This invention relates to photoimageable polymers, particularly those polymers having perfluorocyclobutane groups.

Photoimageable polymers are widely used, especially in the electronics industry to apply coatings of polymer to exact portions of an electronic device, often such that other materials, for instance metals can be applied in regions not coated with polymer. There are a number of ways of achieving the desired results, conveniently classified into positive photoresists, in which the area exposed to light is removed, and negative photoresists, in which the area exposed to light is insolubilized and remains after the unexposed area is removed.

Polyimide negative photoresists are widely used in electronics. Because most polyimides are nearly insoluble in common organic solvents, a soluble precursor is generally used. The precursor has a photosensitive group such as a methacrylate ester group. The photosensitive group results in crosslinking of the precursors on exposure to light of a certain wavelength, such that unexposed precursor can be removed by solvent washing. Then the remaining precursor is converted to polyimide by exposure to heat of 400°C. Exposure to such heat results in loss of the photosensitive groups and water. Loss of such materials requires removal of them and often results in bubbles and shrinkage of from 15 to 50 percent. Photodefinable polyimides that are not subjected to a high temperaure post-cure contain unreacted polyamic acid groups that contribute to increases in the dielectric constant and water absorption of the polymer. Such systems are described in references such as Rohde et al. " Recent Advances in Photoimageable Polyimides," SPIE Vol. 539 Advances in Resist Technology and Processing II (1985).

Those skilled in the art recognize that polyimides, though widely used have various disadvantages. For instance, D. Makino has stated,

Though many kinds of photosensitive polyimides, including positive working or preimidized, have been proposed, their processing latitudes are narrow and their properties are still inferior to thermal cure polyimides, and their application has been limited to a small portion of microelectronics. "Recent Progess of the Application of Polyimides to Microelectronics", Proceedings of the American Chemical Society Division of Polymeric Materials: Science and Engineering, vol. 66, April 1992, p. 233.

Furthermore, when the optical density of the photosensitive material is high in the region of excitation and does not show a hypsochromic shift when irradiated, then most of the photochemistry will occur on the surface. Light intensity will be significantly attenuated

and thus the level of crosslinking will be decreased as a function of depth into the photosensitive layer This results in undercutting of pattern features and creates problems in line width control and integrated circuit fabrication

A number of other polymers have been suggested for use as photoimageable polymers; however, they have not offered properties suitable for use in electronics For instance, certain photoimageable polyesters disclosed by J G Jegal, L H Lin and A Blumstein, Polymer Preprints, Vol. 32, No. 3, August 1991 , pp 205-206, were formed by reaction of 4,4'- Dihydroxy-α-methylstilbene with various dicarboxylic acids, and subsequently crosslinked via irradiation with UV light at 254 nm The resulting polyesters have not been used in thin film dielectric or microelectronic applications because polyesters in general exhibit relatively higher water absorption and dielectric values than polymers currently used in these applications

It would be desirable to have a photoimageable polymer which does not lose water or other materials in its formation or insolubilization, and therefore has less resulting shrinkage, which does not require heating to 300 or 400°C, shows a hypsochromic or bathochromic shift (that is a shift of the absorption maxiumum to shorter or longer wavelengths respectively) when irradiated and which has properties such as low dielectric constant, low dissipation factor, low moisture absorbance, low ionic mobility or ionic transport properties, optical clarity (to visible light) good planarizability, good compatibility of the prepolymer with a wide variety of organic solvents (such as ethers, ketones, aromatics, that is, compounds containing a benzene ring, either substituted or unsubstituted, including fused ring systems such as naphthalene, as is described by Andrew Streitwieser, Jr. and Clayton Heathcock in Introduction to Organic Chemistry, Macmillan Publishing Co., Inc , 1976, p 35 and p. 577, polar aprotic solvents to facilitate application methods such as spin coating, spray coating, dip coating, roll coating, pad printing and the like, but after thermal curing and/or no curing yields a finished polymer with good solvent resistance and good resistance to chemical etchants such as acids and bases

In one aspect the invention is a polymer having at least one photoactive site and more than one perfluorocyclobu tane group The invention also includes monomers containing photoactive sites or photoactive precursors for making such polymers

In another aspect, the invention includes the uses of such polymers in coatings and in negative photoresists

In yet another aspect the invention includes processes of making such polymers and the monomers from which they are made

Polymers of the invention have at least one photoactive site, that is a grouping of atoms capable of absorbing energy from incident photonic radiation such that the polymer becomes less soluble or dispersible in at least one solvent or dispersing medium than it was before exposure to the incident photonic radiation. Compounds of the invention also have such photoactive sites or photoactive precursors; in which case, a polymer made at least partially from such compounds containing photoactive sites becomes less soluble or dispersible upon photonic irradiation. Decreasing solubility or dispersibility is also evidenced by differential solubility between exposed and unexposed polymer, for example in a layer, a first o portion of which is exposed to incident photonic radiation and second portion of which remains unexposed.

The term "incident photonic radiation" or "actinic radiation" refers to energy in the form of electromagnetic waves of a wavelength capable of exciting bonding or non- 5 bonding electrons in certain functional groups referred to herein as photoactive sites or the active portion of such sites to produce a chemical reaction.

The term polymer is used herein to include any compound or compounds comprised of two or more like or different monomer units. Thus the term polymer includes 0 prepolymers, dinners, trimers, tetramers and other oligomers.

Determining reduced solubility or dispersibility is within the skill in the art. For instance, a solid, gel, or organic phase separates from a liquid medium; more solvent is required to dissolve or disperse the same weight of polymer; latex particles coalesce; an 5 emulsion separates or requires additional stirring. The polymer is optionally dissolved or dispersed in any medium effective therefor. For instance, polymers of the invention are advantageously dissolved in solvents such as ethers, ketones, aromatic hydrocarbons, polar aprotic solvents, halocarbon solvents and the like. Among these solvents, mesitylene, diglyme, n-methylpyrrolidinone, and dimethylformamide are advantageously used in electronic 0 applications such as depositing a layer of polymer on a substrate such as a metal (for example copper, aluminum, indium, tin, silver, gold, platinum, cadminum and alloys thereof), silicon, silicon oxide, gallium arsenide, germanium arsenide, barrium ferrite, alloy of chromium and at least one other metal, ceramitized glass, indium tin oxide, glass, quartz, a like, similar, or different polymer (particularly epoxy resins, polycarbonates, polyesters, polyimides, 5 polystyrenes (particularly syndiotactic), benzocyclobutenes, acrylics, other perfluorocyclobutane-containing polymers having differenct aryl groups and combinations thereof), graphite, combinations of the.above and the like. Similarly, the polymer may be dispersed in an aqueous and/or organic medium particularly in an aqueous medium. For

instance, in the form of a latex or emulsion. Reduced solubility or dispersibility is believed to be associated with increased molecular weight of the polymer, for instance from increasing chain length, or preferably crosslinking Preferably, the decreased solubility or dispersibility is a result of chemical changes (chemical reactions), which more preferably result in the formation of covalent bonds. Formation of coatings and other layers of this type of polymer is advantageously as disclosed in U.S Patent 5,246,782 (Kennedy et al )

Polymers of the invention additionally have more than one perfluorocyclobutane group. Methods of making polymers having perfluorocyclobutane groups are disclosed in U.S Patents 5,021,602; 5,023,386; 5,037,917, 5,037,918 and 5,037,919. U.S. Patent 5,021,602 (Clement et al.) discloses compounds of the formula:

CF2- CF2

G _n ^R — ^{x CF} — ^CF — ^x ' ^R ' — ( -G ' ) n '

(hereinafter Formula I)

wherein R and R' independently represent optionally inertly substituted hydrocarbyl groups; X and X' represent any molecular structures which link R and R' with the perfluorocyclobutane ring; n and n' are the number of G and G' groups, respectively; and G and G' independently represent any reactive functional groups or any groups convertible into reactive functional group and methods for making such compounds and forming polymers therefrom

U.S. Patent 5,023,380 (Babb et al) discloses compounds of the formula:

CF ₂ = CF-X-R-(X-CF = CF ₂ )m

(hereinafter Formula II)

wherein R represents an unsubstituted or inertly substituted hydrocarbyl group; each X is independently selected from the group consisting of groups having at least one non-carbon

atom between R and -CF = CF ₂ ; and m is an integer of from 1 to 3 and methods for making such compounds and forming polymers therefrom.

U.S. Patent 5,037,919 (Clement, et al.) discloses compounds of the formula:

(G) _n -R-(X-CF = CF ₂ ) _m

(hereinafter Formula ill)

wherein R represents an optionally substituted hydrocarbyl group, X represents any group which links R and a trifluorovinyl (perfluorovinyl, trifluoroethenyl, or perfluoroethenyl) group; n is the number of G groups, m is the number of (XCF = CF ) groups; and G represents any reactive functional group or a group convertible into a reactive functional group and methods for making such compounds and forming polymers therefrom.

These patents and U.S. Patent 5,037,917 (Babb et al.) and 5,037,918 (Babb) all of which are incorporated herein by reference in their entireties disclose methods of forming polymers having perfluorocyclobutane rings by heating monomers having trifluorovinyl groups, by reacting compounds having perfluorocyclobutane groups such as compounds of Formula I with di- or polyfunctional compounds reactive with the groups designated G and/or G'; and by reacting compounds having a reactive group (G) and at least one trifluorovinyl group such as compounds of Formula III with oligomers or polymerizabie compounds followed by polymerization.

The disclosed methods are applicable for forming polymers of the invention. In the practice of the present invention, however; at least a portion of the compounds used in forming the polymers have photoactive sites. In the practice of the invention R and R' preferably have from 6 to 100 carbon atoms, more preferably from 6 to 50 carbon atoms, most preferably from 6 to 25 carbon atoms. For instance, the molecular fragments designated R and R' in Formulas l-lll optionally have photoactive sites. Photoactive sites include those having at least two conjugated multiple bonds (wherein the term "multiple bonds" is used to include double, triple or aromatic bonds between two carbon atoms, between a carbon atom and a heteroatom such as an oxygen, nitrogen, sulfur, phosphorus or between two or more heteroatoms such as between sulfur and oxygen, phosphorus and oxygen or sulfur, nitrogen and oxygen, or nitrogen and nitrogen such that incident photonic radiation is absorbed by the molecule.

Exemplary photoactive sites include molecular groups such as:

R'

(stilbenes)

(styrenes)

(1 -aryl propenyl)

(coumarins)

(benzylidenecyclohexanones)

iaryl-1,4-pentadiene-3-

O

CH ₂

O' (for example acrylates, methacrylates, such

R" as:

O

(maleimides)

(naphthoquinones)

(polyacetylenes)

= OH; y = O-R", namaldehydes

(β,β'-bis(benzoyl) αivinylbenzene, for example with o, m, or p substituted middle ring)

in each case wherein each R" is H or a hydrocarbyl group which is optionally inertly substituted, preferably H or a hydrocarbyl group of from 1 to 12 carbon atoms, more preferably H or an alkyl hydrocarbyl group of from 1 to 6 carbon atoms; and Y stands for a bond to any

(2-cinnamvlidene and higher cyclohexanones)

(1,9-bis(aryl)-1 ,3-6,8-nonatetraene-5-one and higher polyaryl alkyl polyenones)

where each n is independently an integer 0 to 11.

(2,6-bis(cinnamylidene and higher) cyclohexanones)

where each n is independently an integer of from 0 to 11.

(polyenone cycloalkylenes) where each n is independently an integer of from 1 to 12 and with optional addition unsaturation in the cycloalkylring

enzophenones)

other atom or group of atoms (for example H, OH, OR, R", SH, SR", NHR", and the like).

Any photoactive site or compound containing such a site is optionally inertly substituted, that is substituted with any group which does not undesirably affect the function of the photoactive site.

The photoactive site (represented hereinafter as "PAS") is optionally any part of a compound and optionally becomes part of a polymer backbone or side chain. For instance, when the photoactive site corresponds to at least a portion of R in Formula II, a monomer is represented:

CF ₂ = CF-X-PAS-(X-CF = CF ₂ ) _q

(Formula IV)

wherein X is as defined for Formula I; PAS is a photoactive site or photoactive precursor as defined previously; and q is an integer of from 0 to 4. When such a compound is polymerized by formation of perfluorocyclobutane groups from the trifluorovinyl groups, the photoactive sites are in the polymer backbone. Alternatively, the photoactive sites are in side chains such as when a compound such as

CF ₂ = CF ₂ -X-R" _ (X-CF = CF ₂ ) _q

(PAS).

(Formula V)

wherein X is as defined for Formula I; R" is as defined for R and R' of Formula I exceptthat it is substituted with PAS which is as defined for Formula IV; q is an integer of from 0 to 4; and r is an integer from 1 to 4 is similarly polymerized. Compounds of Formula IV or V are novel compounds of the invention.

Alternatively, photoactive sites are formed on already formed polymers having plural perfluorocyclobutane groups, such as by reaction of compounds having photoactive sites or photoactive precursors that are subsequently converted to photoactive sites with any polymer formed by a process taught in any of the already cited patents disclosing perfluorocyclobutane containing polymers.

When the polymer of the invention is formed at least partially from compounds corresponding to Formulas I, II or III wherein R and/or R' contain at least one photoactive site (as in Formula IV or V), the compounds are suitably formed by methods disclosed in the cited references from starting materials having the desired photoactive sιte(s) or from starting materials having precursors for the photoactive sites When zinc is used to form trifluorovinyl groups from bromotetrafluoroethyl groups, it is preferable to use precursors for photoactive sites containing carbon-carbon double bonds conjugated with aromatic rings and carbon- oxygen double bonds because such double bonds are often attacked by zinc under reaction conditions For instance, para-perfluoroethenyloxybenzaldehyde can be formed by reaction of zinc with para-bromotetrafluoroethoxybenzaldehyde; then for instance, the para- perfluoroethenyloxybenzaldehyde can be condensed in an aldol condensation with a ketone, either two moles of the aldehyde with a ketone like acetone or one mole of the aldehyde with a tπfluoroethenyl compound containing a ketone group e.q. para- perf luoroethenyloxyacetophenone to form

O

O luoroethenyl-

/ )-1,4-

CF ₂ = CF e-3-one)

(4,4'-bis(trifluoroethenyloxy)chalcone)

respectively

A process for making such compounds is then:

(a) forming a salt having an anion corresponding to a compound (acid) of Formula VI:

HX-PAP-(XH) _α

VI

wherein X and q are defined as for Formula IV; and PAP and PAP' are photoactive precursors (any group(s) which can react to form a photoactive group), where PAP represents a group which can be modified to become photoactive (either a single group or a group illustrated by the benzaldehyde and acetophenone groups in the above illustration which can react, optionally with other reactants, to become a photoactive site);

(b) reacting the salt with a 1,2-dihalo-1,1,2,2-tetrafluoroethane wherein the halo groups are iodine, bromine, chlorine or mixtures thereof, at least one halo group being a bromine or an iodine atom, to form a compound of Formula VII;

Z-CF ₂ CF ₂ -X-PAP-(X-CF ₂ CF ₂ -Z) _q VII

wherein PAP, X and q are defined as for Formula VI; and each Z is independently iodine or bromine;

(c) eliminating the halogen atoms represented by Z to form the trifluorovinyl compound(s); and

CF ₂ = CF-X-PAP-(X-CF = CF ₂ ) _q VIII

wherein X, PAP, and q are as defined for Formula VI.

(d) modifying the photoactive precursors (PAP) to form photoactive sites

(PAS) to form compounds represented by Formula IV.

CF ₂ = CF-X-PAS-(X-CF = CF ₂ ) _q

Step d is suitably before or after step(s) b and/or c. Those skilled in the art are able to ascertain suitable order of steps from chemical sensitivity and reactivities of groups present with reactants used in the steps.

It should be noted that groups represented by PAP, and PAS optionally include groups which are not photoactive along with the photoactive groups. For instance the molecular structure between the X's in Formula IV is optionally not itself totally photoactive but has, for instance a pendant photoactive group or a reactive group to which a photoactive site may be attached.

The step of modifying the photoactive precursor(s) optionally includes reactions which combine like or different precursors to form a photoactive site as illustrated by the condensation of aldehydes and ketones already discussed. Alternatively, one site in a molecule is chemically modified. For instance, a photoactive site of unsaturation (carbon-carbon double bond) may be generated from a non-photoactive precursor by the acid catalyzed α, β- dehydration of an alkyl alcohol. Alternatively, a photoactive site may be modified via reactive substitution to change the quantum yield or absorption maximum of the chromophore. For instance, the compound 4-(trifluoroethenyloxy)-β-(4-nitrobenzylidene) acetophenone, formed bythe Aldol condensation of 4-(trifluoroethenyloxy)acetophenone with 4-nitrobenzaldehyde, is suitably catalytically hydrogenated using palladium on carbon to reduce the nitro group to an amine, thereby changing the absorption spectrum of the chromophore. The resulting amine is optionally subsequently reacted with iodomethane to form the dimethylamine compound to further change the absorption characteristics of the chromophore.

Steps (a) through (c) of the process are advantageously carried out as described in U.S. Patent 5,023,380.

Compounds of Formula IV where q is at least 1 are homo or copolymerized to form polymers having photoactive sites and perfluorocyclobutane groups.

In a variation on this process, a compound of Formula VI where q is 0 is used to form a compound of Formula IV where q is 0 and wherein the molecular structure represented by PAP includes a group reactive with at least one compound to become a photoactive site. The compound CF = CF-X-PAP has onetrifluorovinyl group which is reacted into perfluorocyclobutane-containing polymers (by processes such as those disclosed in U.S. Patents

5,037,917 and 5,037,918), which polymers then have side chains corresponding to molecular structures represented by PAP. Exemplary of compounds of Formula VI where q is 0 are p- perfluoroethenyloxyacetophenones (optionally substituted for instance with cyano, nitro, sulfonate ester, sulfonamide, trifluoromethyl, carboxylic ester, aldehyde, ketone, or halo (preferably fluoro, bromo or chloro) groups in the ortho and/or meta positions) which are reactive, for instance under acid conditions (including hydrochloric acid in ethanol) with optionally substituted benzaldehydes. Such electron donating substituents as methoxy, ethoxy, or dimethylamino groups para to an aldehyde or propenaldehyde group act to move the wavelength of light absorbed by the resulting chalcone group from 300-320 nm to 340-420 nm wavelengths, for instance 414 nm in the case of the p-dimethylammo substituted aldehyde Electron releasing groups such as secondary or tertiary amines, hydroxy groups, ethers, alkoxy groups preferably of from one to 12 carbon atoms or alkyl groups preferably having from 1 to 12 carbon atoms, on the benzaldehyde act to further induce charge separation and cause the resulting compound to absorb light at longer wavelengths. Benzaldehyde is illustrative of aldehydes useful in the process; such aldehydes include unsubstituted or inertly substituted, cinnamaldehydes, acroleins, furfural, heptadienals (and other polyene aldehydes), retinals, phenyl-2,4-pentadienal terephthaldehyde, naphthalenedicarboxaldehyde, furylpolyene aldehydes and combinations thereof.

In yet another variation of the process, a compound of Formula VI where q is 0 is reacted with a compound having at least two, preferably at least three, trifluorovinyl groups such that a perfluorocyclobutane group is formed in a compound having at least one, preferably at least two, more preferably two, trifluorovinyl groups for subsequent polymer formation. Such compounds include reaction products of 1,1 ,1-tris (4'- trifluoroethenyloxyphenyl) ethane with compounds of Formula IV such as 1-acroyloxy-2-(4- trifluoroethenyloxy)-benzoyloxyethane and 1-methacroyloxy-2-(4-trifluoroethenyloxy)- benzoyloxyethane and the like.

Similarly, compounds of Formula III are advantageously formed by the process disclosed in U.S. Patent 5,037,919 wherein R contains a photoactive site or by a modification of that process wherein steps a' through c' are advantageously carried out as described therein and step d' involves formation of the photoactive site:

(a') preparing a 2-halotetrafluoro compound of the Formula IX

(Q-CF ₂ -CF ₂ -X-) _m -PAP-(G") _n

or at least two compounds, at least one of each of Formula X and XI

(Q-CF ₂ -CF ₂ -X) _m -PAP'

and

PAP'-(G") _n XI

wherein X, PAP, m and n are as defined for Formulas I and II, and Q is bromine, chlorine or iodine: and G" is a functional group G; as previously defined, or a functional group suitable for conversion into G: and each PAP' is independently the same or different photoactive precursor which react with one another to form a photoactive site;

(b') chemically modifying group G" to produce functional group G;

(c') dehalogenating the 2-halotetrafluoro compound to form the corresponding trifluorovinyl compound; and

(d') modifying the photoactive precursors to form photoactive sites thus forming novel compounds of the invention represented by Formula XII:

(G) _n -PAS-(X-CF = CF ₂ ) m

Step d' is carried out as step d in the process for making compounds of Formula VIII and optionally takes place between steps a' and b', b' and c', after c', or simultaneously with steps b' or c', but preferably after step c'. Also, step b' may take place before or after step c' or step d' : For instance; the hydroxy group of β-(4-hydroxybenzylidene)-4-trifluoro- ethenyloxyacetophenone may be converted to an acetate by treatment with acetyl chloride in tetrahydrofuran.

Exemplary of compounds of Formula XII are β-(4-hydroxybenzylidene)-4-

(trifluoroethenyloxy)acetophenone, β-(4-Acetyl benzyl idene)-4-

(trifluoroethenyloxy)acetophenone, β-(4-Acetyloxybenzylidene)-4-(trifiuoroethenyloxy) acetophenone, β-(4-aminobenzylidene)-4-(trifluoroethenyloxy)acetophenone, β-(4- carboxybenzylidene)-4-(trifluoroethenyloxy)acetophenone, β-(4-isocyanatobenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-chlorocarboxybenzylidene)-4- (trifluoroethenyioxy)acetophenone, β-(4-carboxymethylbenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-carboxyethyl benzyl idene)-4- (trifluoroethenyloxy)acetophenone, 4-hydroxy-β-(4-

trifluoroethenyloxybenzylidene)acetophenone, 4-amino-β-(4- tπfluoroethenyloxybenzylιdene)acetophenone, 4-carboxy-β-(4- tπfluoroethenyloxybenzylidene)acetophenone, 4-chlorocarboxy-β-(4- trιfluoroethenyloxybenzylidene)acetophenone, 4-ιsocyanato-β-(4- trιfluoroethenyloxybenzylidene)acetophenone, 4-carboxymethyl-β-(4- trιfluoroethenyloxybenzylidene)acetophenone, 4-carboxyethyl-β-4- (trifluoroethenyloxybenzylidene)acetophenone, 1-(4-hydroxyphenyl)-2-(4- trifluoroethenyloxyphenyl)-1-propene, 2-(4-hydroxyphenyl)-1-(4-trifluoroethenyloxyphenyl)-1- propene, 1-(4-aminophenyl)-2-(4-trifluoroethenyloxyphenyl)-1-propene, 2-(4-aminophenyl)-1- (4-trifluoroethenyloxyphenyl)-1-propene, 1-(4-carboxyphenyl)-2-(4- trifluoroethenyloxyphenyl)-1-propene, 2-(4-carboxyphenyl)-1-(4-trifluoroethenyloxyphenyl)-1- propene, 1 -(4-chlorocarboxyphenyl)-2-(4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4- chlorocarboxyphenyl)-1-(4-trifluoroethenyloxyphenyl)-1-prope ne, 1-(4-isocyanatophenyl)-2-(4- <trifluoroethenyloxyphenyl)-1 -propene, 2-(4-isocyanatophenyl)-1-(4- trif I uoroethenyloxyphenyl)- 1 -propene, 1 -(4-carboxymethyl phenyl)-2-(4- trifluoroethenyloxyphenyl)-1-propene _f 2-(4-carboxymethylphenyl)-1-(4- trifluoroethenyloxyphenyl)-1 -propene, 4-hydroxy-4'-trifluoroethenyloxystilbene, 4- aminophenyl-4'-trifluoroethenyloxystilbene, 4-carboxyphenyl-4'-trifluoroethenyloxystilbene, 4-isocyanato-4'-trifluoroethenyloxystilbene, 4-carboxymethyl-4'-trifluoroethenyloxystilbene, 5-hydroxy-8-trifluoroethenyloxynaphthoquinone, 1-(4-hydroxyphenyl)-5-(4- trifluoroethenyloxyphenyl)-1 ,4-pentadien-3-one, 1-(4-aminophenyl)-5-(4- tri f I uoroethenyl oxyphenyl )- 1 ,4-pentad i en-3-one, 1 -(4-ca rboxyphenyl )-5-(4- trifluoroethenyloxyphenyl)-1 ,4-pentadien-3-one, 1 -(4-carboxymethyl phenyl)-5-(4- trifluoroethenyloxyphenyl)-1,4-pentadien-3-one, 1-(4-isocyanatophenyl)-5-(4- trifluoroethenyloxyphenyl)-1 ,4-pentadien-3-one, 5-hydroxy-8-trifluoroethenyloxycoumarin, 8- hydroxy-5-trifluoroethenyloxycoumarin, 5-amino-8-trifluoroethenyloxycoumarin, 8-amino-5- trifluoroethenyloxycoumarin, 5-isocyanato-8-trifluoroethenyloxycoumarin, 8-isocyanato-5- trifluoroethenyloxycoumarin, 2-(4-hydroxybenzylidene)-6-(4- trifluoroethenyloxybenzylidene)cyclohexanone, 2-(4-hydroxybenzylidene)-6-(4- trifluoroethenyloxybenzylidene)-4-methylcyclohexanone, 2-(4-aminobenzylidene)-6-(4- trifluoroethenyloxybenzylidene)cyclohexanone, 2-(4-aminobenzylidene)-6-(4- trifluoroethenyloxybenzylidene)-4-methylcyclohexanone, 2-(4-carboxymethyl benzyl idene)-6- (4-trifluoroethenyloxybenzylidene)cyclohexanone, 2-(4-carboxymethylbenzylidene)-6-(4- trifluoroethenyloxybenzylidene)-4-methylcyclohexanone, 2-(4-isocyanatobenzylidene)-6-(4- trifluoroethenyloxybenzylidene)cyclohexanone, 2-(4-isocyanatobenzylidene)-6-(4- trifluoroethenyloxybenzylidene)-4-methylcyclohexanone, 2-(4-chlorocarboxybenzylidene)-6- (4-trifluoroethenyloxybenzylidene)cyclohexanone, 2-(4-chlorocarboxybenzylidene)-6-(4- trifluoroethenyloxybenzylidene)-4-methylcyclohexanone

Compounds of Formula XII are optionally dimerized as discussed in U .S. Patent 5,021 ,602 to form compounds of Formula I. Polymers are formed as described in U.S. Patents 5,037,919; 5,021 ,602; 5,037,917 and 5,037,918, which are incorporated by reference in their entirities.

Alternatively, compounds of Formula XII wherein X is oxygen, PAS = ArC(0)CH = CH-Ar wherein Ar is preferably of from 6 to 50 carbon atoms, and G is a reactive site such as hydroxyl, amine, carboxylic acid, carboxylic acid halide, cyanate, or isocyanate are o reacted (through the group represented by G) with such compounds as alkyl diamines, diols, dicarboxylic acids, dicarboxylic acid halides, phosgene, etc. to form polyesters, polyethers, polycarbonates, polyamides, polyurethanes, end capped with trifluoroethenyloxy groups. These compounds are then heated to cause dimerization of the trifluoroethenyloxy end groups, thereby creating perfluorocyclobutane ring containing polymers with photoactive sites 5 included in the polymer backbone. These polymers are suitably dissolved and applied as coatings by any means within the skill in the art such as spin-coating, roll coating, spray coating, pad printing and the like. The coating is then exposed to light of the appropriate wavelength to crosslink the polymer. This photocuring process crosslinks the exposed polymer and thereby imparts increased solvent resistance, increased mechanical properties, and modified optical 0 properties with respect to the unexposed polymer or prepolymer.

Alternative methods for preparing polymers of the invention include a process of preparing a compound of Formula XIII:

5 PAS-R(-X-CF = CF ₂ ) _t

wherein PAS, R, and X are as defined for Formula IV and t is an integer of from 1 to 4 by

(a") forming the salt of an anion corresponding to a compound (acid) of formula XIV: 0

H-X-R-(X-H) _t _.

³ AP

5 wherein X, R, and t are as defined for Formula XIII and PAP is as defined for Formula VI;

(b") reacting the salt with a 1 ,2-dihalo-1 , 1 ,2,2-tetraf luoroethane wherein the halo groups are iodine, bromine, chlorine or mixtures thereof, at least one halo group being a bromine or an iodine atom, to form a compound of Formula XV:

Z-CF ₂ -CF ₂ -R-(X-CF ₂ -CF ₂ -Z) _t. .

PAP

wherein R, X, PAP and t are as defined for Formula XIV are as each Z is independently bromine or iodine

(c") eliminating the halogen atoms represented by Z to form the trifluorovinyl compound; and

(d") modifying the photoactive precursor to form a photoactive site, forming compounds represented by Formula XIII.

PAS-R-(X-CF = CF ₂ ) _t

Step (d") is carried out as steps (d) and (d') and optionally occurs before step a", between steps a" and b" or b" and c", simultaneous with steps a", b", or " or, preferably,after step c". For instance, the acetyl group of 1-(4-acetophenyl)-1 ,1-bis(4- trifluoroethenyloxy)phenyl ethane is optionally combined via Aldol condensation with benzaldehyde or variously substituted benzaldehydes to form 1-(4-(β- benzylidene)acetophenyl)-1,1-bis(4-trifluoroethenyloxy phenyl)ethane.

In an important embodiment of the process of the invention PAP is a molecular structure having a group reactive with at least one compound having or suitable for forming a photoactive site (a photoactive site-containing or photoactive precursor-containing compound). In this embodiment, the step of reacting with such a compound is represented as at least a part of step d". When there are steps of reacting such a PAP with at least one such compound and of converting a resulting PAP into a PAS, the reacting and converting steps are optionally consective or separated by one or more of steps b" and c".

Preferred species formed by such a process are compounds of the formula XVI:

PAS

which compounds are novel. Wherein R is an unsubstituted or inertly substituted hydrocarbyl group preferably of from 1 to 10, more preferably of from 1 to 4 carbon atoms. R is optionally and advantageously substituted with functional groups which provide additional desirable properties to the polymer, for example a photosensitizing group such as those within the skill in the art.

Compounds exemplary of Formula XIII include 1-(4-acroyloxyphenyl)-1,1-bis(4- trifluoroethenyloxyphenyl)ethane, 1-(4-methacroyloxyphenyl)-1 ,1-bis(4- trifluoroethenyloxyphenyl)ethane, 1-(4-acroyl phenyl)- 1,1 -bis(4- trifluoroethenyloxyphenyl)ethane, 1-(4-methacroylphenyl)-1 ,1-bis(4- trifluoroethenyloxyphenyl)ethane, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β- (benzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- dimethylaminobenzylidene) acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- methoxybenzylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- trifluoromethylbenzylidene) acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- carboxymethylbenzylidene) acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- nitrobenzylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- chlorobenzylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- fluorobenzylidene)acetophenone, 4-(1 ,1-bis(4-trifluόroethenyloxyphenyl)ethyl)-β-(4- acetylbenzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4- cyanobenzylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)styrene, 4-(1 ,1- bis(4-trifluoroethenyloxyphenyl)ethyl)-N-phenyl maleimide, 1-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl)-5-phenyl-1 ,4-pentadiene-3-one, 1-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-(dimethylamino) phenyl) -1 ,4-pentadiene-3-one, 1-(4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-methox yphenyl)- 1 ,4-pentadiene- 3-one, 1-(4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-(carbo xymethyl)phenyl)- 1 ,4-pentadiene-3-one, 1-(4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-

(carboxyethyl)phenyl)-1 ,4-pentadiene-3-one, 1-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-(trifluoromethy l)phenyl)-1 ,4-pentadiene-3-one, 1-(4-(1 , 1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-nitroph enyl)-1 ,4-pentadiene-3- one, 1-(4-( 1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-chloro phenyl)-1 ,4- pentadiene-3-one, 1-(4-(1 , 1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4-fluorop henyl)- 1 ,4-pentadiene-3-one, 1-(4-(1 ,1 -bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5-(4- acetophenyl)-1 ,4-pentadiene-3-one, 1 -(4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl)-5- (4-cyanophenyl)-1 ,4-pentadiene-3-one, 4-(1, 1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl acetylene, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)phenyl buta-1 ,3-diyne, 4-(1 , 1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl hexa-1 ,3,5-triyne, 4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl octa-1,3,5,7-tetrayne, 4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenyl-1,3,5,7,9-pentayne, 6-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenoxy)naphthoquinone, 6-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenoxy)coumarin, 7-(4-(1 ,1-bis(4- trifluoroethenyloxyphenyl)ethyl)phenoxy)coumarin, 2-(4-(1 ,1- bis(trifluoroethenyloxyphenyl)ethyl)benzylidene)cyclohexanon e, 2-(4-(4-( 1 ,1- bis(trifluoroethenyloxyphenyl)ethyl)phenoxy)benzylidene)cycl ohexanone, 1-acroyloxy-2-(4- trifluoroethenyloxy)benzoyloxyethane, 1-methacroyloxy-2-(4- trifluoroethenyloxy)benzoyloxyethane, N-(4-trifluoroethenyloxyphenyl)acrylamide, N-(4- trifluoroethenyloxyphenyl)methacrylamide, 4-trifluoroethenyloxyphenyl acrylate, 4- trifluoroethenyioxyphenyl methacrylate, N-(4-trifluoroethenyloxyphenyl)maleimide, N-(4- trifluoroethenyloxybenzoyl)maleimide, β-(4-methoxybenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-dimethylaminobenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-carboxymethylbenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-carboxyethyl benzyl idene)-4- (tri f I uoroethenyl oxy)acetophenone, β-(4-nitrobenzyl idene)-4- (trifluoroethenyloxy)acetophenone, β-(4-chlorobenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-fluorobenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-acetyl benzyl idene)-4- (trifluoroethenyloxy)acetophenone, β-(4-cyanobenzylidene)-4-

(trifluoroethenyloxy)acetophenone, β-(3-trifluoromethylbenzylidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-trifiuoromethylbenzyiidene)-4- (trifluoroethenyloxy)acetophenone, β-(4-trifluoroethenyloxybenzylidene)acetophenone, 4- methoxy-β-(4-trifluoroethenyloxybenzylidene)acetQphenone, 4-dimethylamino-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-carboxymethyl-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-carboxyethyl-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-chloro-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-nitro-β-(4-

trifluoroethenyloxybenzylidene)acetophenone, 4-fluoro-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-acetyl-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-cyano-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-trifluoromethyl-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 3-trifluoromethyl-β-(4- trifluoroethenyloxybenzylidene)acetophenone, 4-trifluoroethenyloxycinnamaldehyde, 4- trifluoroethenyloxycinnamic acid, 4-trifluoroethenyloxycinnamic acid, methyl ester, 4- trifluoroethenyloxycinnamic acid, ethyl ester, 4-trifluoroethenyioxycinnamic acid, isopropyl ester, 4-trifluoroethenyioxycinnamic acid, phenyl ester, 1-(4-trifluoroethenyloxyphenyl)- propen-1-one, 1-(4-trifluoroethenyloxyphenyl)-1-buten-3-one, 5-

(trifluoroethenyloxy)naphthoquinone, 6-(trifluoroethenyloxy)naphthoquinone, 5-(4- (trifluoroethenyloxy)benzoyloxy)naphthoquinone, 6-(4- (trifluoroethenyloxy)benzoyloxy)naphthoquinone, 5-(trifluoroetheny!oxy)coumarin, 6-(trifluoroethenyloxy)coumarin, 7- (trifluoroethenyloxy)coumarin, 8-(trifluoroethenyloxy)coumarin, 5-(4-

(trifluoroethenyloxy)benzoyloxy)coumarin, 6-(4-(trifluoroethenyloxy)benzoyloxy)coumarin, 7- (4-(trifluoroethenyloxy)benzoyloxy)coumarin, 8-(4-(trifluoroethenyloxy)benzoyloxy)coumarin, 2-(4-trifluoroethenyoxylbenzylidene)cyclohexanone, 1-(4-trifluoroethenyloxyphenyl)-5- phenyl-1,4-pentadiene-3-one, 1-(4-trifluoroethenyloxyphenyl)-5-(4-(dimethylamino)phenyl)- 1,4-pentadiene-3-one, 1-(4-trifluoroethenyloxyphenyl)-5-(4-methoxyphenyl)-1 ,4-pentadiene-3- one, 1-(4-trifluoroethenyloxyphenyl)-5-(4-(carboxymethyl)phenyl)- 1,4-pentadiene-3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(4-(carboxyethyl)phenyl)-1 ,4-pentadiene-3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(4-(trifluoromethyl)phenyl)-1,4 -pentadiene-3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(3-(trifluoromethyl)phenyl)-1,4 -pentadiene-3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(4-nitrophenyl)-1,4-pentadiene- 3-one, 1-(4- trifiuoroethenyloxyphenyl)-5-(4-chlorophenyl)-1,4-pentadiene -3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(4-fluorophenyl)-1,4-pentadiene -3-one, 1-(4- trifluoroethenyloxyphenyl)-5-(4-acetophenyl)-1,4-pentadiene- 3-one, 1-(4-methoxyphenyl)-2- (4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4-methoxyphenyl)-1 -(4- trif luoroethenyloxyphenyl)-1 -propene, 1-(4-dimethylaminophenyl)-2-(4- trifluoroethenyloxyphenyl)-1 -propene, 2-(4-dimethylaminophenyl)-1-(4- trifluoroethenyloxyphenyl)-1 -propene, 1 -(4-carboxymethyl phenyl)-2-(4- trifl uoroethenyloxyphenyl)-1 -propene, 2-(4-carboxymethylphenyl)-1 -(4- trifluoroethenyloxyphenyl)-1 -propene, 1-(4-chlorophenyl)-2-(4-trifluoroethenyloxyphenyl)-1- propene, 2-(4-chlorophenyl)-1-(4-trifluoroethenyloxyphenyl)-1 -propene, 1-(4-nitrophenyl)-2- (4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4-nitrophenyl)-1-(4-trifluoroethenyloxyphenyl)-1- propene, 1-(4-fluorophenyl)-2-(4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4-fluorophenyl)-1- (4-trifluoroethenyloxyphenyl)-1 -propene, 1-(4-cyanophenyl)-2-(4-trifluoroethenyloxyphenyl)-

1 -propene, 2-(4-cyanophenyl)-1-(4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4-acetyl phenyl )- 1-(4-trifluoroethenyloxyphenyl)-1 -propene, 2-(4-acetylphenyl)-1-(4- trifluoroethenyloxyphenyl)-1 -propene, 4-methoxy-4'-trifluoroethenyioxystilbene, 4- dimethylaminophenyl-4'-trifluoroethenyloxystilbene, 4-carboxymethyl phenyl-4'- trifluoroethenyloxystilbene, 4-carboxyethylphenyl-4'-trifluoroethenyloxystilbene, 4-nitro-4'- trifluoroethenyloxystilbene, 4-chloro-4'-trifluoroethenyloxystilbene, 4-fluoro-4'- trifluoroethenyloxystilbene, 4-cyano-4'-trifluoroethenyloxystilbene, 4-acetyl-4'- tri f luoroethenyloxysti I bene, 4-tri f I uoromethyl-4'-tri f I uoroethenyloxysti I bene, 1 -(4- dimethyfaminophenyi)-5-(4-trifluoroethenyloxyphenyl)-1,4-pen tadiene-3-one, 1-(4- methoxyphenyl)-5-(4-trifluoroethenyloxyphenyl)-1 ,4-pentadiene-3-one, β-cinnamylidene-4- trifluoroethenyloxyacetophenone, β-(4'-dimethylamιnocinnamylidene)-4- trifiuoroethenyloxyacetophenone, β-(2'-methoxycinnamylidene)-4- trifluoroethenyloxyacetophenone, β-(4'-methoxycinnamylidene)-4- trifluoroethenyloxyacetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β- (benzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- methoxybenzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- dimethylaminobenzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- cyanobenzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- nitrobenzylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyioxyphenyl)ethyl)-β- (cinnamylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(2'- methoxycinnamylidene)acetophenone, 4-(1,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- methoxycinnamylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β-(4'- dimethylaminocinnamylidene)acetophenone, 4-(1 ,1-bis(4-trifluoroethenyloxyphenyl)ethyl)-β- (4'-nitrocinnamylidene)acetophenone, 1,1-bis(4-trifluoroethenyloxyphenyl)-1-(4-(3-(2-furanyl)- 2-propene-1-onyl)phenyl)ethane, 1,1-bis(4-trifluoroethenyloxyphenyl)-1-(4-(5-(2-furanyl)-2,4 - pentadiene-1-onyl)phenyl)ethane, 3,5-bis(trifluoroethenyloxy)-β-(benzylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-β-(4'-methoxybenzylidene)aceto phenone 3,5- bis(trifluoroethenyloxy)-β-(4'-dimethylaminobenzylidene)ace tophenone, 3,5- bis(trifluoroethenyloxy)-β-(4'-cyanobenzylidene)acetophenon e, 3,5-bis _. trifluoroethenyloxy)-β- (4'-nitrobenzylidene)acetophenone, 3,5-bis(trifiuoroethenyloxy)-β- (cinnamylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-β-(2'- methoxycinnamylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-β-(4'- methoxycinnamylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-β- (4'dimethylaminocinnamylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-β- (nitrocinnamylidene)acetophenone, 3,5-bis(trifluoroethenyloxy)-1-(3-(2-(furanyl)-2-propene-1- onyl)benzene, 3,5-bis(trifluoroethenyloxy)-1-(5-(2-(furanyl)-2,4-pentadien e-1-onyl)benzene, 2- (3-phenyl-2-propene-1-onyl)-9,9-bis(4-trifluoroethenyloxyphe nyl)fluorene, 2-(3-(4- methoxyphenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroethenylo xyphenyl)fluorene, 2-(3-(2-

methoxyphenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroethenylo xyphenyl)fluorene, 2-(3-(4- dιmethylaminophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroe thenyloxyphenyl)fluorene, 2-(3- (4-cyanophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroethenyl oxyphenyl)fluorene, 2-(3-(4- nitrophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroethenyloxy phenyl)fluorene, 2,7-bis(3-phenyl- 2-propene-1-onyl)-9,9-bis(4-trifluoroethenyloxyphenyl)fluore ne, 2,7-bis(3-(4-methoxyphenyl)- 2-propene-1-onyl)-9,9-bis(4-trifluoroethenyloxyphenyl)fluore ne, 2,7-bis(3-(2-methoxyphenyl)- 2-propene-1-onyl)-9,9-bis(4-trifluoroethenyloxyphenyl)fluore ne, 2,7-bis(3-(4- dimethylaminophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroet henyloxyphenyl)fluorene, 2,7- bis(3-(4-cyanophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroe thenyloxyphenyl)fluorene, 2,7- bis(3-(4-nitrophenyl)-2-propene-1-onyl)-9,9-bis(4-trifluoroe thenyloxyphenyl)fluorene, 2-(5- phenyl-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluoroethenyloxyp henyl)fluorene, 2-(5-(4- methoxyphenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluoroeth enyloxyphenyl)fluorene, 2-(5-(2- methoxyphenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluoroeth enyloxyphenyl)fluorene, 2-(5-(4- dimethylaminophenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-triflu oroethenyloxyphenyl)fluorene, 2-(5-(4-cyanophenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-triflu oroethenyloxyphenyl)fluorene, 2- (5-(4-nitrophenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluor oethenyloxyphenyl)fluorene, 2,7- bis(5-phenyl-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluoroethen yloxyphenyl)fluorene, 2,7-bis(5-(4- methoxyphenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-trifluoroeth enyloxyphenyl)fluorene, 2,7- bis(5-(4-dimethylaminophenyl)-2,4-pentadiene-1-onyl)-9,9-bis (4- trifluoroethenyloxyphenyl)fluorene, 2,7-bis(5-(2-dimethylaminophenyl)-2,4-pentadiene-1- onyl)-9,9-bis(4-trifluoroethenyloxyphenyl)fluorene, 2,7-bis(5-(4-cyanophenyl)-2,4-pentadiene- 1-onyl)-9,9-bis(4-trifluoroethenyloxyphenyl)fluorene, and 2,7-bis(5-(4-nitrophenyl)-2,4-pentadiene-1-onyl)-9,9-bis(4-t rifluoroethenyloxyphenyl)fluorene.

When R is part of PAS and t is 2, compounds of Formula XIII correspond to

Formula IV. Exemplary compounds of Formula IV include 4,4'-bis(trifluoroethenyloxy)-α- methylstilbene; 4,4'-bis(trifluoroethenyloxy)stilbene; 4-Trifluoroethenyloxy-β-(4- trifluoroethenyloxybenzylidene)acetophenone; 2,6-bis(4- trifluoroethenyloxybenzylidene)cyclohexanone; 2,6-bis(4-trifluoroethenyloxybenzylidene)-4- methylcyclohexanone; 1,4-bis(3-(4-trifluoroethenyloxyphenyl)-2-propene-1-onyl)ben zene; 1,3- bis(3-(4-trifluoroethenyloxyphenyl)-2-propene-1-onyl)benzene ; 1 ,4-bis(3-(4- trifluoroethenyloxyphenyl)-1-propene-3-onyl)benzene; 1 ,3-bis(3-(4- trifluoroethenyloxyphenyl)-1-propene-3-onyl)benzene; 1 ,5-bis(4-trifluoroethenyloxyphenyl)- 1 ,4-pentadiene-3-one; 4-Trifluoroethenyloxy-β-(4- trifluoroethenyloxybenzylidene)acetophenone; 4,4'-bis-(trifluoroethenyloxy)stilbene; 4,4'- bis(trifluoroethenyloxy)-α-methylstilbene; β,β'-bis(4-trifluoroethenyloxybenzylidene)-1 ,4- diacetyl benzene; β,β'-bis(4-trifluoroethenyloxybenzylidene)-1 ,3-diacetylbenzene; β,β'-bis(4- trif I uoroethenyloxybenzylidene)-1 ,2-diacetyl benzene; 5,8-bis(trifluoroethenyloxy)coumarin;

2,6-bιs(4,trifluoroethenyloxybenzylidene)cyclohexanone; 2,6- bιs(4,trιfluoroethenyloxybenzylιdene)-4-methylcyclohexano ne; 5,8- bιs(trιfluoroethenyloxy)naphthoquιnone; β,β'-bιs(4-tπfluoroethenyloxybenzoyl)-1 ,4- divinyl benzene Polymers of the invention include those formed according to the teachings of U.S

Patent 5,037,917 by copolymerizing or reacting such compounds with compounds of Formula II wherein m is greater than 1 to form polymers having (in the case of m = 2) repeating units of Formula XV:

X

CF-CF ₂

I I

CF-CF ₂

I x

I

R

³ AS

wherein X, R, and PAS are as defined for Formulas I and IV.

For instance, the reaction products of compounds of Formula XIII where t = 1 with compounds such as 1,1,1-tris (4'-trifluoroethenyloxyphenyl)ethane, (1,3,5-tris(2-{4- trifluoroethenyloxy)phenylene)-2-propyl benzene), or the (trifluorovinyl etherified) polyphenolic compounds such as Novolac compounds, exemplify polymers of Formula XV. Preferred Novolac compounds correspond to Formula XVI:

wherein p is an integer of from O to 10; each R ⁴ is independently a linear or cyclic hydrocarbylidene or group preferably of from 1 to 20 carbon atoms (more preferably

methylene, dicyclopentadienylene, isopropyiidenelene, fluorenylidene; and the like); and each R5 is independently a hydrogen or an unsubstituted or inertly substituted alkyl or alkyl ether group preferably of from 1 to 6 carbon atoms, preferably of 1 to 3 carbon atoms.

Monomers containing trifluorovinyl or perfluorocyclobutane groups and photoactive groups are suitably homopolymerized or copolymerized, preferably copolymerized, for instance, with any monomer of the types disclosed by U. S. Patents 5,021 ,602; 5,023,380; 5,037,917; 5,037,918; or 5,037,919; by methods disclosed therein. Preferably sufficient monomer having at least one photoactive site or photoactive precursor to form a polymer which becomes less soluble or dispersible upon exposure to photonic radiation is used. Advantageously, at least 0.1 percent by molar composition of such monomers are used in a polymer, preferably at least 1 , more preferably from 1 to 100, most preferably from 5 to 25 mole percent of photoactive site containing monomers are used. The polymer is suitably linear, branched, crosslinked, or a mixture thereof.

To avoid solubility of at least a portion of a photoactive polymer after treatment with actinic radiation, it is advantageous to avoid having low molecular weight oligomers and polymers after photoactive sites have reacted. When a photoactive monomer containing two trifluorovinyl groups is homopolymerized or copolymerized with another monomer containing two trifluorovinyl groups to form a substantially linear thermoplastic polymer with photoactive sites either pendant to or incorporated in the polymer backbone, the molecular weight of such a system is advantageously made as high as possible while still maintaining desirable properties for processability, such as solubility in a solvent suitable for solution coating processes which are within the skill in the art, or melt processability such as extrusion, injection molding or melt blowing. In addition, the molar percent composition of the photoactive site is advantageously optimized to maintain the same features of processability. Optimization of molecular weight and molar composition of the photoactive site enhance the photochemical sensitivity as defined by Minsk et al. in The Journal of Applied Polymer Science, Volume 2, p. 302 (1959), or by Robertson et al. ibid, p. 308.

Similarly, in systems where the photoactive monomer has three or more trifluorovinyl groups, or is polymerized in a system containing a comonomer with three or more trifluorovinyl groups in sufficient quantity to result in a thermoset polymer, the molecular weight of the polymer (preferably prepolymer) is advantageously as close to the gel point of the system as possible while still maintaining processability as defined above, including solvent solubility and/or melt processability. In this case, processability also involves the exclusion of gels or very high molecular weight fractions which may form before the gel point, but which adversely affect the processability of the polymer and the quality of the coatings and

laminates obtained from these prepolymers in applications where properties such as planaπzation and optical uniformity are important In addition, the molar content of the photoactive site is optimized to provide maximum photochemical sensitivity as defined for the linear polymers In general, weight average molecular weights on the order of 5,000 to 500,000, most preferably from 10,000 to 300,000 are useful in these systems

When the polymer is a thermoplastic, however, it is advantageously applied in a liquid media as described but at a weight average molecular weight greater than 20,000, preferably greater than 60,000. Such high molecular weight polymers are advantageously applied in liquid media, preferably solutions such as by spin coating, spray coating, dip coating, pad printing and other methods known to those skilled in the art. Whereas a post application baking step is used for thermoset resins of the invention, thermoplastics are advantageously applied in a sufficiently high molecular weight to obviate the need for a post bake step Alternatively, thermoplastic polymers of the invention are applied in melted form such as in a melt extruder, by melt coextrusion of a multilayer laminate, or by spin coating, dip coating or spray coating the polymer directly from the melt phase. The polymer may also be formed into a free standing film by melt extrusion, blow molding or other means known to those skilled in the art.

Alternatively, the polymer is applied as a dry film as is within the skill in the art for instance as discussed in Printed Circuits Handbook, C. F. Combs, Jr., ed., second ed., McGraw- Hill, New York, 1979, pages 6-12 through 6-13. In a dry film application, a film of photoactive polymer is advantageously supplied as a layer on one, or preferably between two, polymer sheets. The film is advantageously applied to a material such as a conductor, for example copper, is exposed to light such that the viscosity of the exposed photoactive polymer increases leaving the unexposed polymer unchanged for removal.

Photoactive polymers prepared by any of the foregoing methods are advantageously used as coatings. For use as coating, the polymer is preferably prepared in an organic solvent, aqueous medium, emulsion, or latex or is dissolved or dispersed after formation or used as a dry film. The coating is applied to a surface by means within the state of the art, such as by spin coating, spray coating, plasma deposition, roll coating, pad printing, dip coating and the like Then the polymer is exposed or at least a portion of the polymer is selectively exposed to photonic radiation of a wavelength which interacts directly or indirectly with the photoactive sites. Preferably, sufficient photonic radiation is used to render the polymer less soluble or dispersible, more preferably essentially insoluble or not dispersible (that is insufficiently soluble or dispersible to be removed from the surface by rinsing in the solvent

used for application or any other solvent(s) effective for removal of the unexposed portion of the polymer) or more viscous.

The polymer is suitably applied to any surface such as the surface of flat, spherical, irregular shapes, such as glass plates, silicon or silicon oxide wafers such as those used in the production of semiconductor devices, glass beads, copper film, other polymers including for instance polycarbonate, polyimide, polyester, polytetrafluoroethylene or other fluoropolymers, polyquinolines, polybenzoxazoles, polybenzimidazoles, polyaryl sulfones , microelectronic circuitry including multilayer microelectronic circuitry devices or other surfaces of the like which optionally may be prepared by processes such as cleaning by washing with soap followed by rinsing with deionized water and then drying, either in an oven or with a stream of dry gas such as air, or cleaning by a plasma cleaning process such as oxygen plasma or sulfur hexafluoride plasma cleaning. Other surface treatments may include preparing the surface with an adhesion promoter such as bis[3-(triethoxysilyl)propyl]amine using standard conditions such as those outlined in "Silicon Compounds - Register and Review," published by Petrarch Systems Silanes and Silicones (1987), Petrarch Systems.

Any incident photonic radiation which is effective to render the polymer less soluble or dispersible (hereinafter effective wavelength) is suitably used. Such radiation is advantageously at a wavelength which is absorbed by the photoactive site, preferably from 250 nm to 500 nm, for instance 405-436 nm for sites having the 4-dimethylaminochakone group, 300-365 nm for sites having the 4-methoxychalcone group, 254-280 nm for sites having the α- methylstilbene group, 300-365 nm for sites having the (unsubstituted) chalcone group, 300-365 nm for sites having the 1,4-pentadiene-3-one group, and the like. Alternatively, another compound can absorb the photonic radiation and change the available energy. For instance, compounds referred to as photosensitizers, such as benzophenone, 1 ,2-benzanthraquinone, or Michler's ketone are known in the art to absorb light at a wavelength different from the absorption of the photoactive site, and transfer the absorbed energy via collision processes from the photosensitizer to the photoactive site, activating the photoactive site for covalent reaction with an appropriate site for crosslinking. Thus, the photonic energy is suitably used directly or indirectly.

While the photosensitizer compounds are effective to increase the effective wavelength to those more commonly used in industry, use of wavelengths in the mid and deep ultraviolet (UV), that is wavelengths such as the 313 nm (nanometer) line for mid UV, and the 254 nm line for deep UV are advantageous especially for formation of coatings having very fine definition because resolution is improved. Most commonly used photoimageable polymers are active in the near U V region rather than the more desirable mid and deep U V. In a preferred

embodiment of this invention, the photoactive group is active with a wavelength of incident photonic radiation of from 235 to 260 or from 250 to 275 to avoid optical density from the presence of aromatic groups.

Advantageously, to reduce solubility or dispersibility, the photoactive group acts such that crosslinking occurs as a result of incident photonic energy. Crosslinking optionally occurs between like photoactive groups or between a photoactive group and a group which is not photoactive. Most photoactive compounds of the invention react to crosslink through chemical reactions at the photoactive site, and generally involve lower energy (longer o wavelength, for example greater than 320 nm) absorptions of molecules with large and diffuse molecular orbitals, usually spread out over one or more aromatic ring systems. A benzophenone chromophore reacts somewhat differently however, irradiation of benzophenone with light excites the benzophenone carbonyl group to the excited singlet state, which crosses to the chemically active triplet state. During this excitation of the carbonyl 5 group, the n bond is broken and the triplet state can be considered as a 1 ,2 diradical, which is believed to abstract hydrogen from hydrogen-donor molecules such as hydrocarbons, alcohols, ethers, amines, thiols, sulphides, and phenols and produce a benzophenone ketyl radical, also called a diphenylhydroxymethyl radical orsemipinacal radical which radical reacts with another part of the polymer such that crosslinking occurs. 0

In the practice of the invention, it is preferred that crosslinking occurs such that the resulting group is not photoactive or photoabsorptive at the effective wavelength, preferably not photoactive at any wavelength. When photoactive groups continue to absorb photonic radiation at substantially the same wavelength (a wavelength sufficiently close to the 5 effective wavelength to absorb at least a portion of the incident photonic radiation) after solubility or dispersibility is reduced, they prevent that photonic radiation from going deeper into the polymer to cause another photoactive group to react. A material having groups which absorb photonic radiation at a given wavelength are referred to as having optical density at that wavelength. At reduced optical density, there is transparency that permits the photonic 0 radiation to go deeper within a polymer. The deeper penetration of photonic radiation permits curing of thicker films or layers of polymer than is possible in a polymer with a higher optical density. Thus, practice of this preferred embodiment of the invention permits formation of thicker films than is possible in systems where optical density remains after solubility or dispersibility is reduced. For instance films having a high optical density are 5 generally limited to a thickness of less than 10 μm, but films of greater than 2 μm preferably greater than 5 μm more preferably greater than 10 μm are formed in the practice of the invention. Films of the invention are advantageously at least 0.01 μm, preferably at least 0.1 μm, more preferably at least 0.5 μm thick. Formation of

such thick films also is facilitated by the lack of volatiles (water or molecules eliminated in formation of the final polymer film) formed in the practice of the invention

Photoactive groups that result in crosslinking not having optical density at the effective wavelength include chalcones, cinnamates, acrylates, cinnamaldehydes, maleimides, 1 ,5-aryl-1 ,4-pentadιene-3-ones naphthoquιnones, coumaπns, (benzy dene) cyclohexanones, 2,6-bιs(benzylιdene)cyclohexanones, 2-cιnnamylιdene cyclohexanones, 1 ,9-bιs(aryl)-1 , 3,6,9- nonatetraene-5-ones, 2,6-bιs(cιnnamylιdene)cyclohexanones, and stilbenes

For use as a negative photoresist, only a portion of the photoactive polymer is exposed to sufficient photonic radiation to render it less soluble or dispersible The remaining portion is referred to as unexposed and is removed by means within the skill in the art such as by a process known as developing, such as by spray development, which includes steps of spraying a film-coated substrate with a continuous stream of atomized or otherwise dispersed stream of a developing solvent for a sufficient time to efficiently remove the uncrosslinked portion of a polymer, followed by a drying step comprised of for instance either oven drying the substrate, or drying with a continuous stream of dry gas such as air or nitrogen, or a combination of both oven-drying and gas drying Alternative means of removing the less soluble portion of polymer include dunk rinsing, which involves immersing the substrate in a bath of the developing solvent for sufficient time to dissolve the uncrosslinked portion of the polymer

When the polymer has remaining trifluorovinyl groups, such as in the case of oligomers or B-staged polymers, the polymer is advantageously heated sufficiently to allow at least a portion of the trifluorovinyl groups to form perfluorocyclobutane groups, advantageously further building molecular weight of the polymer such that it becomes less soluble, more oxidatively and thermally stable, less swellable by contact with solvent, and attains a low dielectric constant and a dissipation factor which is characteristic of the perfluorocyclobutane ring containing polymers Temperatures and conditions for forming perfluorocyclobutane groups are those disclosed in the previously cited patents

Such coatings are also advantageously optically transparent and may be suitable as scratch resistant or chemically resistant coatings on optical lenses or other devices where optical transparency is an important feature

Polymers formed in the practice of the invention advantageously have low moisture absorption, preferably moisture absorption of less than 2 percent, low dielectric constant, preferably below 3 5, low dissipation factor, preferably below

01 , flame retardency, good mechanical properties such as tensile modulus and flexural modulus of at least 150,000 psi (1 ,034,213 kPa) chemical resistance, such as resistance to hydrocarbon, aromatic ring-containing solvents including benzene, chlorobenzene, nitrobenzene, toluene, xylene, mesitylene, and the like, ketone or halocarbon solvents, and 5 high thermal-oxidati ve stability, preferably above 100°C, preferably 150°C, more preferably 200°C, (advantageously formulated without added antioxidant) Polymers with at least some of these properties are particularly useful in fabrication of dielectric polymer films for microelectronics applications

10 The following examples are offered to illustrate but not limit the invention

Examples (Ex.) of the invention are designated numerically, while Comparative Samples (CS) are not examples of the invention and are designated alphabetically All parts, ratios, percentages and fractions are by weight unless designated otherwise

15 Example 1 : Synthesis and Polymerization of 4,4'-Bιs(tπfluoroethenyloxy)-α-methylstιlbene

4,4'-Bιs(2-bromotetrafluoroethoxy)-α-methylstιlbene

4,4'-bis(hydroxy)-α-methylstιlbene (100 0 g, 0 442 mole) was added to a 3 liter, 4 20 necked round bottomed flask along with DMSO (dimethylsulfoxide) (1150 ml) and toluene (350 ml). The resulting mixture was deoxygenated with nitrogen for 15 minutes, then OH (58.4 g, 0.884 mole as 85 percent pellets, the remaining 15 percent being water) was added all at once The mixture was stirred and heated to reflux, and water was removed azeotr opically by distillation of the water/toluene azeotrope for a total of 10 hours A Soxhlet extractor 25 containing a drying bed of anhydrous Na2S04 was placed on the reactor, and the toluene was refluxed through this drying bed to remove residual water. Toluene (260 ml) was removed by simple distillation, then the remaining mixture was cooled to 24°C. 1,2- Dibromotetrafluoroethane (276 g, 1.06 mole) was added slowly over 30 minutes, and the reaction mixture was stirred at 24 ^C C for 8 hours After filtration and evaporation, the residue 30 was flushed through a column of alumina using hexane as the eluent Hexane was removed by evaporation, and the resulting residue weighed 109 4 g (0 19 mole) for an isolated yield of 42 percent

Mass Spectrometπc Analysis: m/e(mass/charge ratio) = 165 (9 6 percent), 179 (9.5 percent), 35 387 (10 0 percent); 389 (10.0 percent); 582 (41 1 percent); 583 (21.5 percent); 584 (100 percent), 585 (20 6 percent); 586 (47.1 percent)

4,4'-Bιs(trιfluoroethenyloxy)-α-methylstιlbene

The intermediate product 4,4-bιs(2-bromotetrafluoroethoxy)-α-methylstιlbene ( 106 43 g, 0 18 mole) was added to 100 ml of acetonitπle in a 250 ml dropping addition funnel attached to a 1 liter 5-necked round bottomed flask. Zinc granules (40 mesh, 25.0 g, 0.38 mole) were added to the reactor along with 100 ml of acetonitπle, and the resulting stirred suspension was deoxygenated with nitrogen for 10 minutes by introducing nitrogen gas through a gas dispersion tube. The suspension was then heated to 75°C, at which point the addition of intermediate product solution in acetonitπle was begun. The addition was carried out over 20 minutes, and the resulting mixture was heated at 75°C overnight. After centnfugation to remove suspended solids, the resulting supernatant was evaporated to dryness, leaving a crude product which was filtered through a short bed (4 cm) of alumina in a 600 ml sintered glass filter funnel using hexane as the eluent. After removal of the hexane by evaporation, the product was heated at 55 ^G C under high vacuum for 30 minutes

Mass Spertrometric Analysis: m/e = 191 (20.7 percent); 192 (12.2 percent); 386 (100 percent); 387 (22.2 percent).

α-Methylstilbene Perfluorocyclobutyl Ether Polymer:

A small sample (2.0g) of the 4,4'-bis(trifluoroethenyloxy)-α-methyl-stilbene monomer was placed in a 50 ml 3-necked round bottomed flask fitted with a mechanical stirrer and a temperature controller. The monomer was agitated slowly as nitrogen was bubbled through the liquid for 5 minutes. The temperature of the flask was raised to 160°C for 90 minutes, then to 180°C for 60 minutes, and finally to 200°C for 90 minutes. After it was cooled to room temperature, the resulting polymer was recovered by breaking pieces of the polymer out of the reaction flask, and a small portion of the polymer was dissolved in benzene. The benzene solution was filtered to remove any insoluble portion of the polymer and deposited on a salt plate for infrared (IR) analysis. The benzene was evaporated at 130°C in an oven to leave a thin polymer film deposited on the salt plate.

Examination of the IR spectrum of the polymer revealed a medium absorption at

837 cm-1 , indicative of a carbon-hydrogen stretch associated with the hydrogen attached to a carbon-carbon olefin bond between two aromatic rings in the α-methylstilbene structure. The salt plate was then placed under UV irradiation at 254 nm for 3 hours. Analysis of the UV-cured film by IR indicated a significant decrease in the carbon-hydrogen absorption at 837 cm-1. This loss of intensity at 837 cm-1 was attributed to the disappearance of the carbon-carbon double bond between the aromatic rings of the α-methylstilbene as this structure dimerized

upon irradiation with UV light at 254 nm. Subsequent irradiation overnight with light of 254 nm wavelength produced little change in the spectrum as compared to irradiation for 3 hours

The resulting polymer film deposited on the salt plate was washed extensively with benzene in an effort to dissolve and thereby remove the polymer film which had originally been deposited from benzene solution After being washed in 50 ml of benzene for 5 minutes, the salt plate was removed and the benzene allowed to evaporate to dryness The IR spectrum of the salt plate was taken again, and no measurable loss of absorption intensity of the polymer film was observed with respect to the film before washing with benzene. This demonstrated that the polymer film was substantially intact after being washed with the solvent originally used to deposit the soluble form of the polymer, and indicated a degree of crosslinking in the polymer sufficient to render it insoluble in a solvent in which it was soluble prior to irradiation with UV light at 254 nm.

Example 2: Copolymeπzation of 20 Mole Percent 4,4'-Bis(trifluoroethenyloxy)-α- methylstilbene with 80 mole Percent 1 ,1 ,1-Tris(4-trifluoroethenyloxyphenyl)ethane (TVE Monomer) and Subsequent Photocrossl inking of the Copolymer

A mixture of 4,4'-bis(trifluoroethenyloxy)-α-methylstilbene (1.01 g, 0.0026 mole) and 1,1,1-tris(4-trifluoroethenyloxyphenyl)ethane (prepared here and in all examples as described in U.S. Patent 5,066,746) (5.66 g, 0.010 mole) was placed in a 100 ml round bottomed flask equipped with a mechanical stirrer and and deoxygenated by introducing nitrogen into the flask through a gas dispersion tube for 10 minutes. The resulting mixture was then heated to 150°C with stirring for one hour. The resulting prepolymer was cooled to room temperature, and a I.O g sample of the prepolymer was removed from the flask. This sample was combined with 10 ml of benzene in a 100 ml Erhlenmeyer flask and heated to 45°C with stirring for 1 hour. The resulting polymer solution was deposited on a NaCl salt plate and the benzene solvent was evaporated to dryness in a drying oven at 120°C. Infrared (IR) analysis of this salt plate showed an absorption spectrum of the copolymer, with characteristic IR absorptions at 1605 cm-1, 1594 cm-1, and 1505 cm-1 , corresponding to the aromatic ring absorptions of the polymer system, and at 1206 cm-1, 1 175 cm-1 , and 1 141 cm-1 , corresponding to the absorption of the carbon-fluorine bonds. After irradiation of the film with UV light at 254 nm wavelength for 64 hours, a broad absorption band of moderate intensity from 1685 cm-1 to 1772 cm-1 appeared The salt plate was immersed in benzene and washed by swirling the benzene solvent over the salt plate for two minutes. Subsequent IR analysis of the washed plate revealed no decrease in the absorbance intensity, indicating that the polymer film was still substantially intact. This example demonstrated that the polymer was

rendered insoluble to a solvent in which it was soluble before irradiation by irradiation with UV light at 254 nm wavelength.

Example 3: Synthesis of 1 ,5-Bis(4-trifluoroethenyloxyphenyl)-1 ,4-pentadιene-3-one

4-(2-bromotetrafluoroethoxy)benzaldehyde:

Method 1 :

Dimethylsulfoxide (210 ml) and toluene (75 ml) were placed in a 500 ml 5-necked round bottomed flask equipped with a mechanical stirrer, a Barrett trap topped with a nitrogen padded reflux condenser, and a thermocouple attached to a temperature controller which controls a heating mantle on the flask through a Variac rheostat power supply. The solution was deoxygenated by bubbling nitrogen into the reactor for 10 minutes. Potassium hydroxide (KOH) (23.0 g, 0.35 mole as 85.5 percent pellets, the remainder was water) was added to the solution and the mixture was heated to 1 10°C to dissolve the KOH. 4-

Hydroxybenzaldehyde (42.7 g) was added in two equal portions. The solution was heated to reflux to begin water removal. When 14 ml of lower phase had been collected in the Barrett trap, the trap was replaced with a Soxhlet extractor containing anhydrous Na2S04 (sodium sulfate), and the residual water in the toluene was removed by distilling the toluene through this Na2S04 drying bed. Toluene (50 ml) was removed by simple distillation, and the resulting mixture was cooled to 60°C. 1,2-Dibromotetrafluoroethane (140 g, 0.538 moles) was added slowly and the mixture was heated to 70°C. After 2.5 hours of heating at 70°C, the mixture was heated to 85°C overnight. The resulting reaction mixture was cooled, filtered and extracted with hexane (4 times, 400 ml each). The hexane extracts were combined and washed with distilled water (6 times, 500 ml each). After evaporation of the hexane a yellow oil remained, which was flash distilled on a Kugelrohr apparatus (80°-90°C, 0.20 mm Hg (26.6 Pa)) to provide a colorless liquid (8.35g, 0.028 mole) in 7.9 percent yield.

Method 2: Powdered 4-hydroxybenzaldehyde (351.4 g, 2.584 mole) was added slowly to a stirred solution of KOH (169.5g, 2.584 mole as 85.5 percent pellets also containing 15 percent water) in 1600 ml of methanol which had been thoroughly deoxygenated by introducing nitrogen through a gas dispersion tube for a period of 15 minutes. The mixture was stirred for 1 hour under a nitrogen atmosphere, then evaporated to yield a purple solid. This solid product was placed in a vacuum drying oven at 5 mm Hg (665 Pa) and 1 10°C for 5 hours, then removed, ground into a fine powder and placed in the vacuum drying oven at 5 mm Hg (665 Pa) and 1 10°C overnight. A total of 410.5 g (2.56 mole, 99.3 percent yield) of the potassium salt of p-hydroxybenzaldehyde was isolated by this method.

A portion of this salt (208 0 g, 1 3 mole) was added to 1200 ml of DMSO in a 3-lιter round bottomed flask fitted with a vacuum sealed mechanical stirrer, a thermocouple well, a gas inlet valve and a Soxhlet extractor and condenser unit which was connected to a vacuum pump An oven dried ceramic thimble in the Soxhlet extractor contained activated 5A molecular sieves The mixture was stirred slowly under high vacuum and heated to distill the DMSO through the Soxhlet drying apparatus This distillation was continued until the DMSO solution measured 500 ppm H20 by Karl-Fishertitration

After the system was vented to ambient pressure under dry nitrogen and the reaction mixture was cooled to 45°C, 1 ,2-dιbromotetrafluoroethane (390 g, 1 50 mole) was slowly added to the reaction mixture through a dropping addition funnel A temperature of 45°C was maintained throughout the addition, and thereafter for 1 hour The temperature was then raised to 50°C for 30 minutes, then to 55°C for 20 minutes, then to 65°C for 1 hour, and finally to 75°C overnight. After being cooled to room temperature, the resulting crude reaction mixture was extracted with hexane (6 times with 1 liter portions). The hexane extracts were combined and evaporated to leave a portion of the product as a yellow oil. The remainder of the product was codistilled from the crude reaction mixture with the DMSO solvent. This DMSO/product mixture (1 liter) was diluted with 1200 ml of water and extracted again with hexane (4 times with 1 liter portions) These hexane extracts were combined with the yellow oil from the first extraction and washed with 250 ml of distilled water. After evaporation of the hexane layer, a light yellow oil remained This oil was flash evaporated on a rotary evaporator (75°C, 0 5 mm Hg (66.5 Pa)) to provide a water white oil (136 07 g, 0 452 mole, 34 8 percent yield), 98 6 percent pure by gas chromatography (GC) analysis

Mass Spectrometnc Analysis- m/e = 299 (58 percent), 300 (33 percent); 301 (100 percent); 302 (13 percent); 303 (31 percent)

4-Trιfluoroethenyloxybenzaldehyde-

Acetonitrile (300 ml) and granular zinc (30.0 g) were combined in a 1 liter round bottomed flask and stirred at 75°C under nitrogen as 4-(2- bromotetrafluoroethoxy)benzaldehyde (1 1 1 39 g, 0 37 mole) was added slowly by dropping addition funnel The resulting mixture was stirred and heated at 79°C for 12 hours After filtration to remove zinc salts and unreacted zinc, the acetonitrile was removed under vacuum on a rotary evaporator The resulting oily residue was flash distilled on a rotary

evaporator under high vacuum (26.6 Pa) to provide 47.33g (0.234 mole) of a water white oil in 63.3 percent yield.

Mass Spectrometric Analysis: m/e = 51 (56 percent); 77 (65 percent); 105 (31 percent); 127 (37 percent); 154 (21 percent); 201 (34 percent); 202 (100 percent); 203 (70 percent).

Alternatively the compound was prepared from methyl-4-hydroxy-benzoic acid, salts or esters thereof or from phenol.

1 ,5-Bis(4-trifluoroethenyloxyphenyl)-1 ,4-pentadiene-3-one:

Method 1 :

Acetone (0.70g, 0.012 mole) and 4-trifluoroethenyloxybenzaldehyde (5.0g, 0.0247 mole) were combined in reagent alcohol (90 percent ethanol, 5 percent methanol, and 5 percent isopropyl alcohol, available from Fisher Scientific) (30 ml) in a 250 ml jacketed 3-necked round bottom flask equipped with a mechanical stirrer, a nitrogen padded reflux condenser with a downstream gas flow indicator (a bubbler)and an inlet gas dispersion tube. The solution was cooled to 0°C with stirring by circulating chilled glycol through the jacket of the reaction vessel, and was deoxygenated by introducing nitrogen through a gas dispersion tube into the solution for 15 minutes. A temperature of 0°-5°C was maintained as the nitrogen gas flow was ceased and the alcohol solution was saturated with HCI (hydrochloric acid) by introducing gaseous anhydrous HCI through the gas inlet tube. The solution was stirred at 5°C for 5 hours, then filtered, and the precipitate washed with 20 ml of fresh alcohol. The white crystalline product thus obtained (1.4 g, 0.0032 mole, 27.4 percent yield) had a melting point of 1 13°- 1 14.5°C.

Mass Spectrometric Analysis: m/e = 76 (16 percent); 102 (33 percent); 203 (13 percent); 329 (1 1 percent); 426 (100 percent); 427 (24 percent).

Method 2:

Reagent alcohol (1 10 ml) and 4-trifluoroethenyloxybenzaldehyde (20. Og, 0.099 mole) were combined in the apparatus of Method 1 (with the addition of a septum on one neck of the apparatus, through which was introduced the needle of a syringe containing the reagent acetone), deoxygenated as in Method 1 and cooled to 0°C with stirring. The temperature was maintained at 0°-5°C as the alcohol solution was saturated with anhydrous HCI as in Method 1. When the alcohol solution had reached saturation, as was

, the addition of acetone (2 87g, 0 0495 mole) was begun The acetone was added in small portions (0 50 ml each) at 30 minute intervals, for a total addition time of 3 5 hours The continuous feed of anhydrous HCI gas was allowed to continue overnight at a slow pace ( 10 ml per minute) The HCI feed was then stopped and nitrogen gas was bubbled through the solution for 1 hour to remove some of the dissolved HCI The reaction mixture was then filtered, and the precipitate was washed twice with deionized water (50 mi each) The precipitate was air dried for 20 minutes to provide 10 46g (0 0245 mole) of the desired product The filtrate was evaporated to a red oil, which was dissolved in acetonitrile (70 ml) and extracted with two portions of hexane (600 ml each) The extracts were combined and evaporated to provide an additional 0.55g of the product, for a total of 1 1 01g (0 0258 mole, 52 2 percent yield) as a light pink crystalline solid with a melting point of 1 1 -113°C

Example 4 Preparation and Photocrosslinkmg of a Copolymer of 1 ,5-Bιs(4- trιfluoroethenyloxyphenyl)-1 ,4-pentadιene-3-one and 4,4'-Bιs(trιfluoroethenyloxy)bιphenyl

A sample of the monomer 4,4'-bιs(trιfluoroethenyloxy)bιphenyl, prepared as described in U S Patent 5,023,380 (1.42 g, 0 0041 mole) was combined with the monomer 1,5- bιs(4-trιfluoroethenyloxyphenyl)-1,4-pentadιene-3-one (0.58 g, 0 00136 mole) in a 100 ml 3 necked round bottomed flask fitted with a mechanical stirrer, a temperature controller and a nitrogen inlet The reactor was swept with nitrogen as the mixture of monomers was heated to 155°C The temperature was controlled at 155°C for 2 hours; then the heat was removed A portion of the resulting yellow prepolymer was removed, dissolved in dichloromethane (CH2CI2) and deposited between two NaCl salt plates for IR analysis The two salt plates were rubbed together with the solution of prepolymer between them, then separated The solvent was allowed to evaporate from each plate, leaving roughly identical films of prepolymer on each of the two plates

One plate was placed in a plastic bag and stored in the dark as a control for the experiment The second plate was placed in a round bottomed flask, and the flask was deoxygenated carefully with nitrogen This plate was then subjected to irradiation with a 15 watt GE F15T8/BLB blacklιght (360 nm) for 90 minutes The two salt plates were then analyzed by IR spectroscopy The first salt plate (experimental control) exhibited a complex absorption structure in the region normally associated with carbon-carbon double bonds, with small to medium absorptions at 1674 cm-1 , 1657 cm-1 , 1623 cm-1, 1604 cm-1 , and 1585 cm-1 By contrast, the IR spectrum of the plate which had been subjected to irradiation at 360 nm showed only a single absorption band in this region at 1606 cm-1 , all other absorptions in this region becoming minimal This indicated that irradiation of the polymer film on the second salt

plate had effected a change in the absorbance of the carbon-carbon double bond region of the IR spectrum by causing a light-induced intermolecular dimerization of some of the pentadienone carbon-carbon double bonds.

The second salt plate was then placed back in the round bottomed flask and irradiated with the blacklight for an additional 16 hours, while the first plate was returned to dark storage for the same period of time. Subsequent IR analysis of the two plates showed no noticeable differences from the spectra taken previously, after the second plate had experienced only 90 minutes of irradiation at 360 nm.

The two salt plates were then simultaneously placed in a 250 ml evaporating dish containing 50 ml of CH ₂ CI ₂ , just enough to completely immerse the plates. The evaporating dish was then swirled gently for 1 minute to wash the solvent back and forth across the surfaces of the salt plates. The two plates were then removed and analyzed again by IR spectroscopy. The first plate, which had been stored in the dark, shows no absorption spectrum at all, indicating that the polymer film which was deposited there had been completely washed away by the CH CI ₂ treatment. The second salt plate, which had been subjected to irradiation with light at 360 nm, showed no decrease in the absorption spectrum after the CH ₂ CI ₂ treatment, indicating that the irradiated film was still substaintally intact. This example demonstrated that a polymer film which had been subjected to photonic radiation was rendered insoluble in a solvent in which it was initially soluble.

Example 5: Synthesis of β-(4-trifluoroethenyloxy-benzylidene)-4- trifluoroethenyloxyacetophenone

Method 1 :

4-(2-Bromotetrafluoroethoxy)acetophenone

4-Hydroxyacetophenone (351.4g, 2.584 mole) was added slowly to a solution of

KOH(169.5g, 2.584 mole as 85.5 percent pellets (remainder water)) in 1600 ml of methanol which had been thoroughly deoxygenated by bubbling nitrogen through a gas dispersion tube. The solution was stirred for 1.5 hours, then evaporated to a wet powder. This powder was dried overnight in a vacuum drying oven at 1 15°C, removing once after 2 hours to grind it to a fine powder with a mortar and pestle. The powder was cooled to room temperature under vacuum in the oven. A total of 448.2 g (2.576 mole, 99.7 percent yield) was recovered as a pink/orange solid.

A portion of this solid (228.2 g, 1 31 mole) was added to 1250 ml of DMSO in a 3- liter round bottomed flask equipped with a vacuum-sealed mechanical stirrer, a thermocouple in a glass thermocouple well, a gas dispersion tube, and a Soxhlet extractor topped with a reflux condenser. A ceramic thimble in the Soxhlet extractor was filled with activated 5A molecular sieves After the mixture was thoroughly deoxygenated by introducing nitrogen through the gas dispersion tube for 15 minutes, the tube was removed and replaced by a glass stopper. The mixture was stirred slowly under high vacuum (266 Pa) and heated to distill the DMSO through the Soxhlet drying apparatus for 4 hours. The solution was vented to o atmospheric pressure under nitrogen and cooled to room temperature. Analysis of the DMSO solution indicates a water content of 420 ppm (parts per million by weight) by Karl Fisher titration. The reaction mixture was chilled to 18°C ιn an ice water bath, and addition of 1 ,2- dibromotetrafluoroethane (400.0 g, 1.54 mole) was carried out over 45 minutes. The mixture was held at 18 ^G C for 30 minutes, then allowed to warm to room temperature. Over the course 5 of one hour the temperature was raised to 50°C and was maintained at 50°C for 18 hours. The temperature was then raised to 65°C for 8 hours, after which the mixture was cooled to room temperature. The DMSO solvent was removed from the product at 85°C/2.0 mm Hg, (266 Pa) and the resulting dark residue was distilled on a Kugelrohr apparatus to provide 82.6 g (0.262 mole, 20.0 percent yield) of the 4-(2-bromotetrafluoroethoxy)-acetophenone. 0

Mass Spectrometric Analysis: m/e = 299 (85.8 percent); 300 (30.1 percent); 301 (100 percent); 315 (19.9 percent), 317 (19.9 percent).

Infrared spectral analysis (cm-1): C = O (1690); Ar (1605, 1504); C-F (1203,1 167,1 132). 5

4-Trifluoroethenyloxyacetophenone

4-(2-Bromotetrafluoroethoxy)acetophenone (82.0 g, 0.406 mole) was combined with 175 ml of acetonitrile and placed in an addition funnel attached to a 500 ml round 0 bottomed flask equipped with a reflux condenser, a mechanical stirrer, and a thermocouple attached to a temperature controller which controls a heating mantle on the flask through a Vaπac rheostat power supply. An additional 25 ml of acetonitrile was placed in the 500 ml flask along with granular zinc (32.0 g, 0.4895 mole). The resulting zinc slurry was stirred and heated to 78°C, at which point the addition of 4-(2-bromotetrafluoroethoxy)acetophenone was 5 begun. The addition was carried out over a period of 45 minutes, during which time the heat was increased to the reflux temperature of the mixture (82°C). After the resulting mixture was stirred at reflux for 5 hours, analysis of

the reaction mixture by gas chromatography indicates that all of the starting acetophenone product had been consumed.

The reaction mixture was then cooled to room temperature and decanted away from the unreacted zinc granules into water (400 ml) which had been acidified with 20 ml of 12 N HCI. This aqueous mixture was extracted with dichloromethane (2 times, 250 ml each). This extract was evaporated to provide a yellow oil which was distilled on a rotary evaporator at 85°C and 2 mm Hg (266 Pa). The resulting product was flushed through a short bed of neutral aluminum oxide using hexane as an eluent to provide 27.9 g (0.138 mole, 34 percent yield) of the 4-trifluoroethenyloxyacetophenone product as a water white oil.

Mass Spectrometric Analysis: m/e = 76 (22.4 percent); 91 (41.0 percent); 104 (38.5 percent); 201 (100 percent); 216 (22.1 percent); 217 (12 percent).

Infrared Spectral Analysis (cm-1): C = O (1689); Ar (1602, 1502); C-F (1203, 1 169, 1 144).

Alternatively, the compound was prepared from ethyl phenol or phenol.

β-(4-trifluoroethenyloxybenzylidene)-4-trifluoroethenylo xyacetophenone

Reagent alcohol (150 ml, Fisher Scientific) was combined in a 1 liter jacketed round bottomed flask with 4-trifluoroethenyloxyacetophenone (25.0 g, 0.1 16 mole) and 4- trifluoroethenyloxybenzaldehyde (23.4 g, 0.1 16 mole). The flask was equipped with a mechanical stirrer, a thermometer, and a gas dispersion tube. The mixture was stirred as chilled glycol coolant was circulated through the flask jacket to cool the mixture to 3°-5°C. Nitrogen gas was bubbled into the mixture through the gas dispersion tube to deoxygenate the solution. The inlet gas was then switched from nitrogen to anhydrous HCI and the feed rate was controlled to maintain a solution temperature of 5°C. This HCI feed was continued for 4.5 hours, at which point the HCI feed was stopped and the stirring was continued for an additional hour.

Cold water (250 ml) was then added slowly to the reactor. The resulting light yellow precipitate was filtered from the liquid, washed twice with 200 ml each of cold deionized water, then dissolved in 1000 ml of hot (60°C) hexane. The resulting hexane layer was decanted away from the water layer and chilled in an ice bath to recrystallize the product. After filtration to remove the precipitate, the hexane filtrate was concentrated by evaporation on a rotary evaporator at 60°C and chilled again to cause the crystallization of the product.

Three batches of crystals were thus collected from the hexane phase and were

combined to provide 26.9 g, (0.067 mole, 58.0 percent yield) of a fluffy white powder, melting point 93.5°-94.0°C.

Mass Spectrometric Analysis: m/e = 102 (20.4 percent); 104 ( 17.1 percent); 178 (19.8 percent); 201 ( 17.2 percent); 206 (21.0 percent); 303 (37.3 percent); 399 (51.4 percent); 400 ( 100 percent); 401 (50,9%).

Method 2:

β-(4-(2-bromotetrafluoroethoxy)benzylidene)-4-(2-bromote trafluoroethoxy)acetophenone

A sample of 4-hydroxy-β-(4-hydroxybenzylidene)acetophenone (4,4'- dihydroxychalcone, prepared according to the procedure of Zahir in Journal of Applied Polymer Science, volume 23, page 1355, (1979)) (229. Og, 0.954 mole) was added to dimethylsulfoxide (DMSO) and toluene in a 2 liter 5-necked round bottom flask equipped with a mechanical stirrer, a Barrett trap topped with a nitrogen padded reflux condenser, and a thermocouple attached to a temperature controller which controls the power output to a heating mantle on the reaction vessel through a variable rheostat power source. The solution was deoxygenated by introducing nitrogen through a gas dispersion tube for 15 minutes. Potassium hydroxide pellets (125.4g, 85 percent KOH by weight, the balance being water) were added to the solution and heating was begun. The nitrogen gas dispersion tube was removed and replaced with a glass stopper when the KOH pellets were completely dissolved, that was when the solution temperature reaches 1 10°C. The solution was heated to reflux (138°C), and water was removed through the Barrett trap via azeotropic distillation with the toluene. A total of 99 ml of lower phase was removed from the Barrett trap over the course of 6 hours. The Barrett trap was then removed and replaced with a Soxhlet extractor containing activated 5A molecular sieves. The toluene was then distilled through the Soxhlet extractor drying bed for 3 hours. The Soxhlet extractor was then removed and replaced with the Barrett trap, and toluene (200 ml) was removed through the Barrett trap by simple distillation. The resulting solution was then cooled to 30°C, and the addition of 1 ,2-dibromotetrafluoroethane (600.0g, 2.31 mole) was begun. The addition was carried out at 30°-35°C over a period of 45 minutes. When the addition was complete, the mixture was heated slowly to 75°C over 1 hour and stirred at 75°C overnight.

After being cooled the mixture was added to a large excess of distilled water (4.0

L) and dichloromethane (500 mL) was added to the solution to facilitate phase separation. The dichloromethane phase was removed from the bottom and evaporated to provide crude product as a dark brown oil. The oil was dissolved in acetonitrile (1500mL) and

placed in a continuous liquid/liquid extractor as the heavy source phase in an apparatus as described for continuous extraction for solvents lighter than water by F Kutscher and H Steudel in Zeitschπft fur Physiologische Chemie, volume 39, page 474, (1903) The light phase which was continuously evaporated and recirculated was hexane The extraction was run for 48 hours, and the hexane was evaporated The residue remaining after evaporation was dissolved in toluene (300 ml) and flushed through a short bed of alumina The toluene was evaporated, and a yellow crystalline product remains and was dissolved in a minimum amount of hot hexane (60°C). The hexane was chilled in an ice bath to cause the crystallization of the product. After filtration to remove the precipitate, the hexane filtrate was concentrated by evaporation on a rotary evaporator at 60°C and chilled again to cause the crystallization of the product. After filtration the precipitate fractions were combined to afford 208.6g (0.35 mole, 36.6 percent yield) of the product β-(4-(2-bromotetrafluoroethoxy)benzylιdene)-4-(2- bromotetrafluoroethoxy)acetophenone as a light green solid with a melting point of 89°-90°C.

Mass Spectrometric Analysis: m/e = 63 (16.9 percent); 92 (14.3 percent); 165 (15.8 percent); 299 (17.0 percent); 401 (55.0 percent); 402 (23.4 percent); 403 (60.5 percent); 404 (20.8 percent); 417 (12.7 percent); 419 (16.1 percent); 596 (62.3 percent); 597 (75.1 percent); 598 (100.0 percent); 599 (47.7 percent); 600 (47.6 percent).

β-(4-trifluoroethenyloxybenzylidene)-4-trifluoroethenylo xyacetophenone

The product of the above reaction, β-(4-(2-bromotetr afluoroethoxy)benzylidene)-4-(2- bromotetra-fluoro-ethoxy)acetophenone (5.0g, 0.00836 mole) was combined in a 200 ml 3- necked round bottom flask with 2-τnethoxy ethyl ether (20 ml) and granular zinc (4.37g, 0.067 mole) The slurry was heated to 120°C and stirred with a mechanical stirrer under a nitrogen atomsphere for 24 hours. The resulting reaction mixture was filtered and the filtrate was evaporated at 90°C under reduced pressure (2.0 mm, 266 Pa) to remove the solvent. The residue remaining after evaporation was dissolved in acetonitrile (150 ml) and extracted with hexane (5 portions, 200 ml each). The hexane extracts were combined and evaporated at 60°C and reduced pressure (20 mm, 2670 Pa) to a volume of 100 ml which was then allowed to cool to room temperature from 60°C. The product which crystallized out of the hexane was collected by filtration and washed with cold hexane (25 ml, 5°C). The hexane filtrates were combined and concentrated by evaporation at 60°C and reduced pressure (20 mm, 2670 Pa) to a volume of 75 ml, then allowed to cool again to room temperature. A second batch of crystals was thereby collected after filtration of the hexane concentrate The combined solids weighed 0.60g (0 0015 mole, 17.9 percent yield) and had a melting point of 93.5°-94°C

Examples 6-10 Preparation of Copolymers of 1 , 1 , 1 -Trιs(trιfluoroethenyloxyphenyl)ethane with β-(4-trιfluoroethenyloxybenzylιdene)-4-trιfluoroethenylo xyac etophenone, and a Copolymer of 1 ,1 , 1-Trιs(trιfluoroethenyloxyphenyl)ethane with 1 ,5-Bιs(4-trιfluoroethenyloxyphenyl)-1 ,4- pentadιene-3-one

For each of Examples 6-1 1 , solid white 1 ,1 ,1 -trιs(tπf luoroethenyloxy- phenyl)ethane (TVE Monomer, 200 g) was added to a 500 mL one necked round bottom flask connected to a Kuglerohr apparatus and then deoxygenated at 80°C under vacuum (0 20 mm

Hg, 26 6 Pa) for 2 hours to give a colorless oil The TVE monomer was then mixed with the stated amounts indicated in each example of β-(4-trιfluoroethenyloxybenzylιdene)-4- tπfluoroethenyloxyacetophenone (hereinafter chalcone monomer) prepared by the process of

Example 5 or 1 ,5-Bιs(4-tπfluoroethenyloxyphenyl)-1,4-pentadιene-3-one (hereinafter bischalcone monomer) prepared by the process of Example 3 and B-staged according to the procedure outlined below

Example 6: 5 Mole percent Chalcone/95 Mole percent TVE

TVE monomer (30 g) and chalcone monomer ( 1.18 g) were placed in a long cylindrical reaction vessel equipped with a three necked glass head, a Teflon™ (polytetrafluoroethylene commercially available from E.l. DuPont de Nemours and Co ) seal, a stirrer with a Teflon'" paddle, a screw clamp, a nitrogen inlet, and a vacuum outlet The mixture was stirred at a constant speed, evacuated, vented two times with nitrogen, immersed in a fluidized aluminum oxide sand bath (preheated to 150°C) to 2/3 its height and then heated at 150°C with stirring for 3.50 hours under nitrogen (Heating to achieve partial polymerization was referred to as B-staging.) Upon cooling, the prepolymer was a yellow glass-like solid After the temperature of the prepolymer reaches room temperature (22°-24°C), the reactor was cooled with dry ice to facilitate removal of the prepolymer by cracking the embrittled prepolymer, thereby making it easier to remove from the reaction vessel The prepolymer was ground to a fine powder with a mortar and pestle to give 2845 g of a yellow solid Analysis of the prepolymer by gel permeation chromatography (GPC) indicated a weight average molecular weight of 7,810 for this sample as standardized against polystyrene

Example 7: 10 Mole percent Chalcone/90 Mole percent TVE

TVE Monomer (30 g) and chalcone monomer (2.50 g) were combined and B- staged at 150°C for 4 hours using the procedure of Example 6 to give 29 05 g of yellow solid prepolymer Analysis of the prepolymer by GPC indicated a weight average molecular weight of 13,800 for this sample as standardized against polystyrene

Example 8 10 Mole Percent Chalcone/90 Mole Percent TVE

TVE Monomer (30 g) and chalcone monomer (2 50 g) were combined and B- staged at 150°C for 4 75 hours using the procedure of Example 6 to give 28 02 g of yellow solid prepolymer Analysis of the prepolymer by GPC indicated a weight average molecular weight of 34,800 for this sample as standardized against polystyrene

Example 9 50 Mole percent Chalcone/50 Mole percent TVE

TVE Monomer (30 g) and chalcone monomer (1 1 24 g) were combined and B- staged at 150 ^C C for 4 25 hours using the procedure of Example 6 to give 40 00 g of yellow solid prepolymer Analysis of the prepolymer by GPC indicated a weight average molecular weight of 3, 160 for this sample as standardized against polystyrene

Example 10: 10 Mole percent Bιschalcone/90 Mole percent TVE

TVE Monomer (20 g) and bischalcone monomer (1 77 g) were combined and B- staged at 150°C for 4 hours using the procedure of Example 6 to give 19 00 g of yellow solid prepolymer Analysis of the prepolymer by GPC indicated a weight average molecular weight of 4,400 for this sample as standardized against polystyrene

Examples 1 1 - 15. Spin coating a photosensitive prepolymer onto a 10-centι meter diameter silicon oxide wafer and photocrossl inking the prepolymer film

In the following examples the silicon oxide wafers were pretreated with an adhesion promoter according to the following method

Bιs[3-(trιethoxysιlyl)propyl]amιne (commercially available from Huls America Inc ) (0 50 g) was combined with distilled water (0 50 g) for 14 minutes to promote some prehydrolysis and condensation of the silane functionality This solution was then diluted with 24 ml of methanol to form a 2 weight percent solution of the adhesion promoter in methanol A portion of the adhesion promoter solution (5 ml) was drawn into a syringe and filtered through a 1 0 micron (0 001 mm) filter onto the surface of the silicon wafer which was spinning at 5000 revolutions per minute (rpm) on a Solitec Model 5100 Spin Coater After the adhesion promoter was applied, the substrate continues to spin at 5000 rpm for 90 seconds to evaporate the water and methanol from the adhesion promoter coating

Example 1 1 Photocrosslinking of a Copolymer of 5 Mole Percent Chalcone Monomer/95 Mole Percent TVE Monomer

The prepolymer of 5 mole percent chalcone/95 mole percent TVE monomer from Example 6 above (weight average molecular weight = 7,810 g/mole) was dissolved to make a 50 percent solid solution in mesitylene The prepolymer solution was filtered from a syringe through a 0 2 micron (0 002 mm) filter (to remove small particles) into a 100 mL clean bottle The term 'clean bottle' isused to refer to a bottle which hasbeen cleaned to contain less than 0 001 particle of size 0 30 micron or larger per milliliter of volume The prepolymer solution (2 mL) was then deposited onto a 10 cm round silicon oxide wafer using a spread cycle of 500 rpm for 3 seconds and a spin cycle of 5000 rpm for 30 seconds to give a film of excellent quality (no large variation in film thickness as noted by the absence of unassisted visually detected colored interference patterns on the wafer) The prepolymer film was prebaked at 80°C for 30 minutes to remove residual solvent and to enhance adhesion of the prepolymer onto the subtrate The prepolymer film thickness as determined by an Alpha Step-200 Prof ilemeter was 1.572 microns

The prebaked prepolymer (5 mole percent chalcone/95 mole percent TVE) was exposed to UV light (wavelength range = 290-350 nanometers (nm), 1000 Watts) using a high pressure mercury xenon short arc lamp for an exposure time of 250, 500, 800, and 999 seconds (seconds ) using a fused silica quartz test mask for pattern transfer The exposed film was then developed by soaking in xylene solvent for 15 seconds and then dried under a stream of nitrogen at a temperature of 25 ^C C A negative relief of the pattern on the quartz mask was sucessfully transferred to the polymer upon development as indicated by uncrosslinked areas within the pattern which were washed away by the developing solvent (xylene) The pattern results indicated that an exposure time of 999 seconds was sufficient to crosslink the prepolymer to an extent sufficient to render it insoluble in the developing solvent. Exposure times of 800 seconds or less under these conditions were found to be insufficient to pattern the film Other solvents such as dichloromethane and 2-methoxyethyl ether were also excellent solvents for development under the same development conditions The film thickness measured after UV exposure and development was determined to be 1 485 mιcrons The loss in film thickness was 6 percent after solvent development

Following the general procedure of Example 1 1 , further examples of processing good quality thin films of photodefinable prepolymers onto 10 cm silicon oxide substrates were outlined in the following examples of the invention

Example 12 (10 mole percent chalcone / 90 mole percent TVE)

B-Staging Conditions: 4.0 hours at 150°C;

Spin Coating Conditions: Spread cycle: 500 rpm for 45 seconds.

Spin cycle: 1500 rpm for 30 seconds to yield a 1.4 micron coating after photocrosslinking.

Polymer Prebake and Solvent Evaporation = 80°C for 30 minutes;

UV exposure time: 999 seconds;

Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr (hour) ramp to 210°C (hold 1 hr). ["2 hour ramp to 210°C" refers to raising the temperature from room temperature to 210°C over a 2 hour period; then "hold 1 hr" means the plate was held at 210°C for 1 hour.]

Example 13: (10 mole percent chalcone/ 90 mole percent TVE)

B-Staging Conditions: 4.75 hours at 150°C;

Spin Coating Conditions:

Spread cycle: 500 rpm for 3 seconds.

Spin cycle: 9000 rpm for 30 seconds to yield a 4.4 micron coating after photocrosslinking.

Polymer Prebake and Solvent Evaporation: 80°C for 30 minutes;

UV exposure time: 999 seconds;

Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr ramp to 210°C (hold 1 hr).

Example 14: (10 mole percent chalcone / 90 mole percent TVE)

B-Staging Conditions: 4.0 hours at 150°C;

Spin Coating Conditions:

Spread cycle: 500 rpm for 45 seconds.

Spin cycle: 1500 rpm for 30 seconds to yield a 1.4 micron coating after photocrosslinking.

Polymer Prebake and Solvent Evaporation: 2 hours ramp from 50°C to 120 ^c C (hold 1 hour);

UV exposure time: 999 seconds;

Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr ramp to 210°C (hold 1 hr).

Example 15: (10 mole percent chalcone / 90 mole percent TVE)

B-Staging Conditions: 4.75 hours at 150°C;

Spin Coating Conditions:

Spread cycle: 500 rpm for 3 seconds.

Spin cycle: 9000 rpm for 30 seconds to yield a 4.4 micron coating after photocrosslinking.

Polymer Prebake and Solvent Evaporation: 2 hours ramp from 50°C to 120°C (hold 1 hour);

UV exposure time: 999 seconds;

Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr ramp to 210°C (hold 1 hr).

Example 16: (50 mole percent chalcone / 50 mole percent TVE)

B-Staging Conditions: 4.25 hours at 150°C;

Spin Coating Conditions: Spread cycle: 500 rpm for 3 seconds. j Spin cycle: 9000 rpm for 30 seconds to yield a coating of unknown thickness after photocrosslinking.

Polymer Prebake and Solvent Evaporation: 30 minutes ramp from 50°Cto 120°C (hold 30 minutes);

UV exposure time: 999 seconds;

Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr ramp to 210°C (hold 1 hr).

Example 17: (10 mole percent bischalcone / 90 mole percent TVE)

o B-Staging Conditions: 4.00 hours at 150°C;

Spin Coating Conditions:

Spread cycle: 500 rpm for 3 seconds.

Spin cycle: 9000 rpm for 30 seconds to yield a 1.0 micron coating after photocrosslinking. 5

Polymer Prebake and Solvent Evaporation: 2 hours ramp from 50°C to 120°C (hold 1 hour);

UV exposure time: 500 seconds;

0 Developing solvent: 2-methoxyethyl ether for 15 seconds;

Thermal Cure: 2 hr ramp to 210°C (hold 1 hr). (See Table 1).

Conditions for photodefining the copolymer of the bischalcone (10 mole percent) with TVE (90 5 mole percent) in Example 17 were similar to those in the previous examples, except that the wavelength range of 350-450 nm used for pattern transfer (see Table 2). In an exposure time of 500 seconds, the energy dosage required for crosslinking 10 mole percent bischalcone / 90 mole percent TVE prepolymer film of 4400 weight average molecular weight and 1.0 micron thickness was 30 J/cm ² (at 365 nm). 0

5

40,234-F

Table 1 Photodefinable Conditions of Copolymer of Chalcone Monomer with TVE Monomer

I

J-

00 I

*R was "ramp to" that was increase the temperature from the first temperature over the period indicated before the "R" to the second temperature and hold it there for the final period.

** See explanation on next page.

Chalcone monomer was β-(4-trifluoroethenyloxybenzylidene)-4-trifluoroethenyloxya cetophenone.

25

In the last column, F, D = the quality of the wafer was fair and the polymer film delaminated during developement; E = excellent quality; ND = no delamination; NDT = no delamination on the top side of the wafer; however, some dissolving of the polymer closest to the silicon oxide wafer was observed. G = a good quality film was obtained. The difference between G and E was a subjective evaluation based on the surface appearance of the film, such as a good (G) quality coating appeared smooth and uniform with a non-gloss or matte finish, and an excellent (E) quality film appeared smooth and uniform with a glossy finish.

40,234-F

TABLE 2 Photodefinable Conditions of Copolymer of Bischalcone Monomer with TVE

10

I Ul o

I

* Bischalcone monomer was 1, 5-Bis(4-trifluoroethenyloxyphenyl)-1,4-pentadiene-3-one. **Quality was as for Table 1

15

20

25

Examples 18-20 and Comparative Sample A: Optical Density Measurements and Photobleaching of Photocrosslinkable Prepolymer Films

Solutions of prepolymer (50 percent by weight) with the following compositions;

5 100 mole percent TVE (Comparative Sample A, not an example of the invention), 5 mole percent chalcone / 95 mole percent TVE (Example 18), 10 mole percent chakone/90 mole percent TVE (Example 19), 50 mole percent chalcone/50 mole percent TVE (Example 20) were each separately prepared in mesitylene. The solutions were filtered through a 0.20 micron filter and then spin coated on 10 centimeter quartz substrates using a spread cycle of 500 rpm

10 for 3 seconds and a spin cycle of 9000 rpm for 30 seconds to yield the following film thicknesses before exposure to uv light; 1.042, 1.482, 1.398, 1.280, and 1.000 microns, respectively.

Each coated quartz wafer was exposed to UV light for 999 seconds between the wavelengths of 290-350 nm. The UV absorption spectra for each wafer was analyzed between

15 200 and 500 nm wavelengths with a Perkin Elmer Model Lambda 3B UV/VIS Spectophotometer before and after UV exposure. The spectra of the photocrosslinkable copolymer before photoexposure had the characteristic lambda max (that was the wavelength of maximum absorbance of the prepolymer film in the region of 260 nm to 450 nm); the spectra of the photoexposed prepolymer films had a decrease of absorbance at the position of the lambda 0 rnax of the photocrosslinkable copolymer. The lambda max for the chalcone and bischalcone containing prepolymers were 314 and 330 nm, respectively.

The spectra and the optical density measurements for both photodefinable materials before and after UV exposure indicated that the copolymer "bleaches" (that is, it 5 turns colorless from 260 nm to 500 nm) upon exposure to U V light. Data for the optical density measurements of the chalcone and bischalcone containing prepolymer films at 313 nm, 334 nm, and 365 nm before and after exposure to UV light appear in Tables 3 and 4, respectively.

These examples demonstrated bleaching of these photocrosslinkable copolymers 0 after photoexposure.

5

40,234-F

TABLE 3 Optical Density for Copolymers of Chalcone Monomer with TVE Before Exposure to UV Light

10

I m ts) I

1 5

** Comparative sample not an example of the invention. *Chalcone monomer was as in Table 1.

20

25

40,234-F

TABLE 4 Optical Density (OD) for Copolymers of Chalcone Monomer with TVE After Exposure to UV Light

10

I cn >

I

15 ** Comparatve Sampes not an exampe o t e nventon. *Chalcone monomerwas as in Table 1.

20

25

Example 21 Preparation of β-(4-dιmethylamιnobenzylιdene)-4-trιfluoroethenyloxyace tophe none

4-Tπfluoroethenyloxyacetophenone (prepared in Example 5 above, 10 0 g, 0 046 mole) was combined with dimethylaminobenzaldehyde (commercially available from Aldrich Chemical Co , 7 59 g, 0 051 mole) in 60 ml of reagent alcohol in the apparatus described for the preparation of β-(4-trιfluoroethenyloxybenzylιdene)-4-trιfluoroethenylo xyacetophenone in Example 5, Method 1 , and stirred at 0°-5°C with a slow feed of anhydrous HCI for 78 hours Nitrogen was blown through the reaction mixture to remove some HCI, then the alcohol was evaporated to provide the crude product mixture This mixture was dissolved in dichloromethane and carefully washed with aqueous potassium carbonate to neutralize the acid The dichloromethane was evaporated, and the residue was subjected to column chromatography on alumina using hexane saturated with acetonitrile as an eluent, to provide 1 1 4 g (71 percent) of the β-(4-dιmethylamιnophenyl)-4-trιfluoroethenyloxyacetophen one as an orange crystalline solid with a melting point of 68°-72°C

Spectral analysis of this product indicated a lambda max of 412 nm in acetonitrile solution, with an extinction coefficient of 29,560

Mass Spectrometric Analysis- m/e = 121 (7 4 percent), 146 (6 1 percent), 174 (6 1 percent); 250 (12 3 percent), 347 (100 percent), 348 (30 8 percent) was consistent with identification as β-(4- dιmethylamιno-benzylιdene)-4-trιfluoroethenyloxyacetophe none

Example 22 Copolymeπzation of β-(4-dιmethylamιnobenzylιdene)-4-trιfluoroethenyloxy- acetophenone and TVE monomer

β-(4-dιmethylamιnobenzylιdene)-4-trιfluoroethenyloxy acetophenone (1 4052 g, 0 00404 mole) prepared according to the procedure of Example 21 was combined with the TVE monomer (20 01 g, 0 0366 mole) and mesitylene solvent (21 4 g) in a 200 ml round bottomed flask equipped with a reflux condenser and a thermocouple attached to a temperature controller which controls a heating mantle on the flask through a Variac rheostat power supply A magnetic stirring bar was placed in the flask, and the flask was placed on a magnetic stirrer to provide agitation during the polymerization process The mixture was thoroughly deoxygenated by bubbling nitrogen through a gas dispersion tube into the stirred solution, and was thereafter maintained under a nitrogen atmosphere The solution was heated to 160°C with stirring for 5 hours, then cooled

The molecular weight of the prepolymer was checked by gel permeation chromatography (GPC) as standardized against polystyrene The weight average molecular weight was found to be 6,316 The solution was heated to 160°C for an additional 65 minutes, after which time it was cooled and the molecular weight tested again The weight average molecular weight of the prepolymer was 12,434 as determined by GPC as standardized against polystyrene. The solution was heated to 160°C for an additional 60 minutes, then cooled to test the molecular weight The weight average molecular weight of the prepolymer was 38,442

Example 23: Preparation of β-(4-methoxybenzylιdene)-4-trifluoroethenyloxyacetophenone

4-Trifluoroethenyloxyacetophenone (10.0 g, 0.0463 mole) was combined with 4- anisaldehyde (commercially available from Aldrich Chemical Co.) (6.9 g, 0.050 mole) in reagent alcohol in the apparatus described for the preparation of β-(4- trifluoroethenyloxybenzylιdene)-4-trifluoroethenyloxy-aceto phenone in Example 5, Method 1 above, and was cooled to 0°C-5°C with stirring. After the solution was deoxygenated by bubbling nitrogen through a gas dispersion tube for 10 minutes, anhydrous HCI was introduced into the solution at a rate that maintained a solution temperature of 5°C. After 1.5 hours the solution turned red, and a solid precipitate began to form. The HCI feed was stopped after 4 hours, and nitrogen was blown through the solution to remove some of the HCI. The alcohol was evaporated, and the remaining solid was dissolved in 100 ml of dichloromethane. The dichloromethane solution was carefully washed with aqueous potassium carbonate to neutralize the acid The dichloromethane was then removed from the product by evaporation on a rotary evaporator. Analysis of the final product by gas chromatography indicates that the material was greater than 97 percent pure and requires no further purification.

This product had a melting point of 70.0 ^C -71.5°C.

Spectral analysis of this product indicated that it exhibits a lambda max of 338 nm in acetonitrile solution, with an extinction coefficient of 20,029.

Mass Spectrometric Analysis: m/e = 89 (6.2 percent); 165 (8.6 percent); 303 (8.1 percent); 333 (9.8 percent); 334 (100 percent); 335 (51.3 percent); 336 (8.15 percent) was consistent with identification as β-(4-methoxybenzylιdene)-4-trif I uoroethenyloxyacetophenone

Example 24: Copolymerization of β-(4-methoxybenzylιdene)-4- trif I uoroethenyloxyacetophenone with TVE Monomer:

β-(4-methoxybenzylidene)-4-trifluoroethenyloxyacetophenone ( 1.3544 g, 0.00405 mole) was combined with TVE monomer (20.02 g, 0.0366 mole) and mesitylene solvent (21.37 g) in the apparatus of Example 22, and was deoxygenated thoroughly by introducing nitrogen through a gas dispersion tube for 10 minutes, and thereafter maintaining the solution under a nitrogen atmosphere. The solution was heated to 160 ^c C for 3 hours and 10 minutes, after which time it was cooled and the solution was checked by GPC analysis to ascertain the molecular weight of the prepolymer. The weight average molecular weight of the prepolymer was 379,400.