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Title:
INITIATED CHEMICAL VAPOR DEPOSITION OF 1,1 DISUBSTITUTED ALKENE COMPOUNDS
Document Type and Number:
WIPO Patent Application WO/2019/108680
Kind Code:
A1
Abstract:
A method of coating a substrate using an initiated chemical vapor deposition process is disclosed. The process includes vaporizing a reactive monomer and introducing a polymerization initiator to the reactive monomer. The reactive monomer deposits on a substrate to form a polymeric film. The reactive monomer can be a 1,1-di substituted alkene monomer. Similar systems to coat a substrate are also disclosed.

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Inventors:
STEVENSON, Peter, Rulon (2039 Sheriton Court, Loveland, OH, 45140, US)
SULLIVAN, Jeffrey, M. (6174 State Route 132, Goshen, OH, 45122, US)
VANDERPOOL, Katherine, E. (210 Elm Street, Milford, OH, OH, US)
Application Number:
US2018/062887
Publication Date:
June 06, 2019
Filing Date:
November 28, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SIRRUS, INC. (422 Wards Corner Road, Loveland, OH, 45140, US)
International Classes:
B05D1/00
Domestic Patent References:
WO2014110388A12014-07-17
WO2016040261A12016-03-17
Foreign References:
US20070104860A12007-05-10
US20090087562A12009-04-02
US20170028436A12017-02-02
US6855370B22005-02-15
US20160215398A12016-07-28
US20170050214A12017-02-23
US9217098B12015-12-22
US9416091B12016-08-16
US8609885B22013-12-17
US8884051B22014-11-11
US6458956B12002-10-01
US9181365B22015-11-10
US20150210894A12015-07-30
US9217098B12015-12-22
US9315592B22016-04-19
Attorney, Agent or Firm:
VANDRAKE, Vance, V., III et al. (Ulmer & Berne LLP, 600 Vine StreetSuite 280, Cincinnati OH, 45202, US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A method of coating a substrate comprising: providing a substrate; vaporizing a reactive monomer comprising one or more 1,1 -di substituted alkene monomers; introducing a polymerization initiator to the reactive monomer; and depositing the reactive monomer on the substrate to form a polymeric film.

2. The method according to claim 1, wherein the one or more 1,1 -di substituted alkene monomers comprise one or more of methylene malonate, methylene b-ketoester, methylene b- diketone, dialkyl disubstituted vinyl, dihaloalkyl disubstituted vinyl, monofunctional, difunctional or multifunctional monomer, oligomer, or polymer thereof, and combinations thereof.

3. The method according to claim 1 or claim 2, wherein the one or more 1,1 -disubstituted alkene monomers comprise one or more of diethyl methylene malonate, fenchyl methyl methylene malonate, methylmethoxy ethyl methylene malonate, hexyl methyl methylene malonate, and dibutyl methylene malonate.

4. The method according to any preceding claim, wherein the one or more 1,1 -disubstituted alkene monomers comprise a fluorinated 1,1 -disubstituted alkene monomer.

5. The method according to any preceding claim, wherein the reactive monomer is provided in a reactive monomer composition, the reactive monomer composition further comprising one or more of a liquid phase stabilizer and a gaseous phase stabilizer.

6. The method according to any preceding claim, wherein the vaporizing of the reactive monomer comprises heating the reactive monomer to its respective boiling point.

7. The method according to claim 6, wherein the vaporizing of the reactive monomer occurs under a vacuum pressure from about 1 mmHg to about 4 mmHg.

8. The method according to any of claims 1 to 5, wherein the vaporizing of the reactive monomer occurs by an aerosol spray.

9. The method according to any preceding claim, wherein the polymerization initiator is vaporized by heating the polymerization initiator to its respective boiling point or by an aerosol spray.

10. The method according to any preceding claim, wherein the polymerization initiator comprises l,8-diazabicyclo[5.4.0]undec-7-ene.

11. The method according to any preceding claim, wherein the introducing the polymerization initiator to the reactive monomer initiates polymerization of the reactive monomer in situ in the vapor phase.

12. The method according to any preceding claim, wherein the polymerization initiator is vaporized before the vaporizing the reactive monomer.

13. The method according to any preceding claim, wherein the polymerization initiator is monofunctional, difunctional, trifunctional, or multifunctional.

14. The method according to any preceding claim, wherein the polymerization initiator is in a liquid or solid state and substantially coats at least one surface of the substrate.

15. The method according to any preceding claim, wherein the polymerization initiator comprises 0.1 weight percent tetramethylguanidine in ethanol.

16. The method according to any preceding claim, wherein the polymerization initiator initiates polymerization of the reactive monomer at a surface of the substrate.

17. The method according to any preceding claim, wherein the reactive monomer is deposited on the substrate prior to the step of introducing a polymerization initiator.

18. The method according to any preceding claim, wherein the substrate is formed of an organic material, inorganic material, or composite material.

19. The method according to any preceding claim, further comprising the step of supplying a second reactive monomer comprising a second 1,1 -di substituted alkene monomer, and wherein the second reactive monomer is initiated by the polymeric film.

20. The method according to any preceding claim, further comprising the step of adding an additive to the polymeric film.

21. The method according t any preceding claim, wherein the introducing of the polymerization initiator occurs at ambient temperature.

22. A system comprising: a reaction chamber comprising: a first inlet port for a vaporized reactive monomer comprising a 1 , 1 -di substituted alkene monomer; a second inlet port for a vaporized polymerization initiator; and a mixing zone to combine the vaporized reactive monomer and the vaporized polymerization initiator.

23. The initiated chemical vapor deposition system according to claim 22, wherein the reaction chamber is under a reduced atmosphere of about 1 mmHg to about 4 mmHg.

24. A coated substrate comprising: a substrate; and a polymerized 1,1 -di substituted alkene monomer; and wherein the substrate comprises one or more of a material or shape, wherein the material comprises a fabric and the shape comprises one or more of a curve and cavity.

25. The coated substrate according to claim 24, wherein the 1,1 -di substituted alkene monomer comprises one or more of methylene malonate, methylene b-ketoester, methylene b- diketone, dialkyl disubstituted vinyl, dihaloalkyl disubstituted vinyl, monofunctional, difunctional or multifunctional monomer, oligomer, or polymer thereof, and combinations thereof.

Description:
INITIATED CHEMICAL VAPOR DEPOSITION OF 1,1 DISUBSTITUTED ALKENE

COMPOUNDS

REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the priority of U.S. provisional application Serial No. 62/591,916, entitled INITIATED CHEMICAL VAPOR DEPOSITION OF 1,1 DISUBSTITUTED ALKENE COMPOUNDS, filed November 29, 2017, and hereby incorporates the same application herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure generally relates to thin polymeric films formed from initiated chemical vapor deposition of 1,1 -di substituted alkene compounds.

BACKGROUND

[0003] The application of thin polymeric films to substrates can be useful to provide such substrates with desirable properties such as improved durability, chemical or water resistance, antibacterial resistance, and reduced friction. Known techniques to apply thin polymeric films have suffered from a number of drawbacks however. For example, conventional chemical vapor deposition (“CVD”) techniques including thermal, plasma-assisted, and photo-assisted CVD techniques can damage substrates or undesirably modify surfaces due to damaging temperatures or heterogeneous reactions caused by ions, electrons, or photons generated by CVD processes. Additionally, it can be difficult to modify, or tailor, the thin polymeric films formed from conventional CVD techniques. It would therefore be desirable to provide an improved CVD system and method that can form tailorable thin polymeric films on a substrate under ambient conditions.

SUMMARY

[0004] According to one embodiment, a method of coating a substrate includes providing a substrate, vaporizing a reactive monomer, introducing a polymerization initiator to the reactive monomer, and depositing the reactive monomer on the substrate to form a first polymeric film. The reactive monomer includes one or more 1,1 -di substituted alkene monomers. [0005] According to another embodiment, a system includes a reaction chamber. The reaction chamber includes a first inlet port, a second inlet port, and a mixing zone. The first inlet port is for a vaporized reactive monomer and the second inlet port is for a vaporized polymerization initiator. The vaporized reactor monomer includes a 1,1 -di substituted alkene monomer. The mixing zone mixes the vaporized reactive monomer and the vaporized polymerization initiator.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 depicts a schematic view of an initiated chemical vapor deposition system for simultaneous vapor deposition of a reactive monomer and polymerization initiator according to one embodiment.

[0007] FIG. 2 depicts a side view of a substrate coated with two thin polymeric films according to one embodiment.

[0008] FIG. 3 depicts the experimental setup for Example 4.

[0009] FIG. 4 depicts the experimental setup for Example 5.

[0010] FIG. 5 depicts the experimental setup for Example 6.

[0011] FIG. 6 depicts the experimental setup for Example 7.

DETATTED DESCRIPTION

[0012] As will be appreciated, the application or formation of thin polymeric films to, or on, substrates can provide substrates, and articles containing such substrates, with a variety of beneficial properties and improvements. For example, substrates coated with thin polymeric films can have properties such as improved water and chemical resistance, increased durability, increased conductivity, and reduced friction. Chemical vapor deposition (“CVD”) is a known class of techniques used to form thin polymeric films. CVD techniques are advantageous for their ability to provide coatings to a wide variety of substrates that cannot easily be coated by other techniques and because such techniques can be solvent free. As can be appreciated, the elimination of solvent can eliminate side reactions that can occur in solution and the need to evaporate excess solvent. Known CVD techniques however can suffer from a number of disadvantages.

[0013] For example, thermal-assisted CVD and plasma-assisted CVD can cause damage to temperature-sensitive substrates as a result of the necessary heat required for such CVD processes and the presence of ions and electrons generated during the process which can result in undesirable heterogeneous reactions. Such techniques are also energy intensive. Other CVD techniques such as photo-assisted CVD can also cause undesirable damage or modification of a substrate due to the use of high energy photons.

[0014] An improved CVD process, such as an initiated chemical vapor deposition (“iCVD”) process, can alleviate these disadvantages by forming thin polymeric layers without the high thermal temperatures, plasmas, or high-energy photons required by conventional CVD processes. An iCVD process can instead form thin polymeric layers under ambient conditions through deposition of a vaporized reactive monomer on a substrate.

[0015] As will be described herein, an iCVD process is disclosed which can exhibit desirable growth and reactivity rates at moderate temperatures, can create thin polymeric layers of high chemical purity and adjustable properties, and which is stable with co-precursors and apparatus components during the deposition process. The described iCVD process and coatings does not damage substrates and can be useful for fiber optic applications, electronics and circuitry applications, aerospace applications, lubricious applications, hydrophobic applications, hydrophilic applications, ecological applications, and medical device applications. The described process can also be useful for microfabrication and microelectromechanical systems.

[0016] Generally, the described iCVD process can form thin polymeric layers from one or more vaporized 1,1 -di substituted alkene compounds functioning as reactive monomers and one or more polymerization initiators which initiate polymerization of the 1, 1 -di substituted alkene compounds. The vaporized 1,1 -di substituted alkene compounds can deposit on a substrate following activation to form a thin polymeric film on the substrate.

[0017] As used herein, 1,1 -di substituted alkene compounds can mean compounds having two carbonyl groups bonded to the 1 carbon and a hydrocarbyl group bonded to each of the carbonyl groups. In such 1,1 -di substituted alkene compounds, the hydrocarbyl groups can be bonded to the carbonyl groups directly or through an oxygen atom.

[0018] According to certain embodiments, suitable hydrocarbyl groups for the one or more 1,1- disubstituted alkene compounds can include at least straight or branched chain alkyl groups, straight or branched chain alkyl alkenyl groups, straight or branched chain alkynyl groups, cycloalkyl groups, alkyl substituted cycloalkyl groups, aryl groups, aralkyl groups, and alkaryl groups. Additionally, suitable hydrocarbyl groups can also contain one or more heteroatoms in the backbone of the hydrocarbyl group.

[0019] In certain embodiments, a suitable hydrocarbyl group can also, or alternatively, be substituted with a substituent group. Non-limiting examples of substituent groups can include one or more alkyl, halo, alkoxy, alkylthio, hydroxyl, nitro, cyano, azido, carboxy, acyloxy, and sulfonyl groups. In certain embodiments, substituent groups can be selected from one or more alkyl, halo, alkoxy, alkylthio, and hydroxyl groups. In certain embodiments, substituent groups can be selected from one or more halo, alkyl, and alkoxy groups.

[0020] In certain embodiments, suitable hydrocarbyl groups can be C1-20 hydrocarbyl groups. For example, the hydrocarbyl group can be an alkyl ether having one or more alkyl ether groups or alkylene oxy groups. Suitable alkyl ether groups can include, without limitation, ethoxy, propoxy, and butoxy groups. In certain embodiments, suitable hydrocarbyl groups can contain about 1 to about 100 alkylene oxy groups; in certain embodiments, about 1 to about 40 alkylene oxy groups; and in certain embodiments, about 1 to about 10 alkylene oxy groups. In certain embodiments, suitable hydrocarbyl groups can contain one or more heteroatoms in the backbone.

[0021] Suitable examples of more specific hydrocarbyl groups can include, in certain embodiments, C 1-15 straight or branched chain alkyl groups, C1-15 straight or branched chain alkenyl groups, C5-18 cycloalkyl groups, C 6 -24 alkyl substituted cycloalkyl groups, C 4 -is aryl groups, C4-20 aralkyl groups, and C4-20 alkaryl groups. In certain embodiments, the hydrocarbyl group can more preferably be C i -8 straight or branched chain alkyl groups, C5-12 cycloalkyl groups, C 6 -i2 alkyl substituted cycloalkyl groups, C4-18 aryl groups, C4-20 aralkyl groups, or C4-20 alkaryl groups. [0022] As used herein, alkaryl can include an alkyl group bonded to an aryl group. Aralkyl can include an aryl group bonded to an alkyl group. Aralkyl can also include alkylene bridged aryl groups such as diphenyl methyl or propyl groups. As used herein, aryl can include groups containing more than one aromatic ring. Cycloalkyl can include groups containing one or more rings including bridge rings. Alkyl substituted cycloalkyl can include a cycloalkyl group having one or more alkyl groups bonded to the cycloalkyl ring.

[0023] In certain embodiments, suitable alkyl groups can include methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, pentyl, hexyl, and ethyl hexyl. Similarly, examples of suitable cycloalkyl groups can include cyclohexyl and fenchyl groups. Examples of suitable alkyl substituted groups can include menthyl and isobornyl groups.

[0024] According to certain embodiments, suitable hydrocarbyl groups can include methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, ethyl pentyl, hexyl, ethyl hexyl, fenchyl, menthyl, and isobornyl groups.

[0025] In certain embodiments, illustrative examples of 1,1 -di substituted alkene compounds suitable for use as a reactive monomer for an iCVD process can include methylene malonates, methylene B-ketoesters, methylene B-di-ketones, di-alkyl di- substituted vinyls, di-haloalkyl di- substituted vinyls and any monofunctional, difunctional, or multifunctional monomers, oligomers, or polymers thereof. As can be appreciated, multiple 1,1 -di substituted alkene monomers, such as two or more different methylene malonates, can also be used as the reactive monomers for an iCVD process.

[0026] Suitable 1,1 -di substituted alkene compounds can be monofunctional, difunctional, or multifunctional. Monofunctional compounds can refer to monomers that have a single addition polymerizable group. Difunctional compounds can refer to monomers, oligomers, resins, or polymers that contain two addition polymerizable groups. Multifunctional compounds can refer to any monomer, oligomer, resin, or polymer that contains three or more addition polymerizable groups. In contrast to monofunctional compounds, certain difunctional compounds and multifunctional compounds can undergo additional crosslinking, chain extension, or both when exposed to certain suitable polymerization initiators. As can be appreciated, selection of a monofunctional, difunctional, or multifunctional monomer can determine properties such as the durability of the applied coating layer, the reactivity of the monomer with other additives, and the adhesion strength to a substrate.

[0027] As can be appreciated, the purity of a 1,1 -di substituted alkene compound can affect the polymerization process. For example, the purity of the 1 , 1 -di substituted alkene compounds can influence the glass transition temperature of the polymerized product formed from the 1,1- disubstituted alkenes. In certain embodiments, the purity of a 1,1 -di substituted alkene compound can be sufficiently high such that about 70 mole percent or more, in certain embodiments, 80 mole percent or more, in certain embodiments, about 90 mole percent or more, in certain embodiments, about 95 mole percent or more, and in certain embodiments, about 99 mole percent or more of the 1,1 -di substituted alkene compound is converted to polymer during a polymerization process.

[0028] Additionally, or alternatively, the purity of a 1,1 -di substituted alkene compound can be measured by determining the mole percent that is formed from the monomer. For example, about 85 mole percent or more, about 90 mole percent or more, about 93 mole percent or more, about 95 mole percent or more, about 97 mole percent or more, and about 99 mole percent or more, of the reactive monomer can be a 1 , 1 -di substituted alkene compound in certain embodiments.

[0029] If impurities are present, the impurity can be about 10 mole percent or less in certain embodiments, and about 1 mole percent or less in certain embodiments. In embodiments having a dioxane group impurity, the dioxane group can be present at about 2 mole percent or less, about 1 mole percent or less, about 0.2 mole percent or less, and about 0.05 mole percent or less, based on the total moles of the 1,1 -di substituted alkene compound. The total concentration of any impurity having the alkene group replaced by an analogous hydroxyalkyl group (e.g., by a Michael addition of the alkene with water) can be about 3 mole percent or less, about 1 mole percent or less, about 0.1 mole percent or less, and about 0.01 mole percent or less, based on the total moles in the 1,1 -di substituted alkene compound.

[0030] In certain embodiments, 1,1 -di substituted alkene compounds can be prepared by a process including one or more (e.g., two or more) steps of distilling a reaction product or an intermediate reaction product (e.g., a reaction product or intermediate reaction product of a source of formaldehyde and a malonic acid ester). [0031] An illustrative example of a monofunctional 1,1 -di substituted alkene compound is depicted by general formula I:

wherein each X can independently be O or a direct bond; Ri and R 2 can be the same or different and can each represent a hydrocarbyl group; and R 3 can be H, a Ci-Cx alkyl, or a hydrocarbyl.

[0032] An illustrative example of a multifunctional monomer having more than one methylene group connected by a multivalent hydrocarbyl group is depicted by general formula II:

I

wherein each X can independently be O or a direct bond; R 4 and R 6 can be the same or different and can each represent a hydrocarbyl group; R 5 can be a hydrocarbyl group having n + 1 valences; s and R 7 can independently be H, a Ci-C 8 alkyl, or a hydrocarbyl; and n is an integer of 1 or greater. In certain embodiments, n can be 3 or fewer; and in certain embodiments, n can be 2 or fewer.

[0033] According to certain embodiments, specific examples of suitable polymerizable compositions can include methylene malonate compounds having general formula III

wherein R9 and Rio can be the same or different and can each represent a hydrocarbyl group. For example, in certain more specific embodiments, suitable methylene malonate compounds can include one or more of diethyl methylene malonate (“DEMM”), dimethyl methylene malonate (“DMMM” or“D3M”), hexyl methyl methylene malonate (“HMMM”), ethylethoxy ethyl methylene malonate (“EEOEMM”), fenchyl methyl methylene malonate (“FMMM”), dibutyl methylene malonate (“DBMM”), di-n-propyl methylene malonate, di-isopropyl methylene malonate, and dibenzyl methylene malonate. Additionally, in certain embodiments, certain transesterification reaction products formed from the reaction of methylene malonate compounds with acetates, diacetates, alcohols, diols, and polyols can also be used to form a suitable reactive monomer including the products disclosed in ET.S. Patent No. 9,416,091 which is incorporated herein by reference.

[0034] According to certain embodiments, examples of suitable methylene beta ketoesters can be represented by general formula IV:

wherein Rn and R12 can be the same or different and can each represent a hydrocarbyl group.

[0035] According to certain embodiments, examples of suitable methylene beta diketones can be represented by general formula V: wherein R 13 and R 14 can be the same or different and can each represent a hydrocarbyl group.

[0036] Nearly any 1,1 -di substituted alkene can be useful as the reactive monomer of an iCVD process. As can be appreciated, such flexibility can allow the reactive monomer to be selected for particular properties. For example, a fluorinated polymeric film can be imparted to a substrate by the use of a fluorinated reactive monomer such as the fluorinated 1,1 -di substituted alkene monomer depicted in formula VI:

wherein n is an integer of 1 or greater. The fluorinated monomer depicted in Formula VI can be produced through a transesterification reaction. As can be appreciated, fluorinated surfaces can exhibit high lipophobicity and low coefficients of friction.

[0037] Additional details and methods of making suitable 1,1 -di substituted alkene compounds as well as other suitable reactive monomers are disclosed in U.S. Patent No. 8,609,885; U.S. Patent No. 8,884,051; and WO 2014/110388 each of which are hereby incorporated herein by reference.

[0038] As can be appreciated, 1,1 -di substituted alkene compounds can exhibit a variety of properties that make them particularly suitable for use as reactive monomers in an iCVD process. For example, 1,1 -di substituted alkene compounds can exhibit desirable volatility rates to enable favorable growth and reactivity at moderate vaporization temperatures (e.g., DEMM has a boiling point of about 140 °C to about 145 °C at about 1 atm of pressure and a boiling point of about 65 °C to about 75 °C at 1 mmHg) and reasonable temperature ranges between evaporation and decomposition to allow for polymeric film deposition without precise temperature control. In combination with the ready availability of 1 , 1 -di substituted alkene monomers in high chemical purity, the favorable temperature ranges also allows for the formation of polymerized films in high yields and at relatively low costs compared to comparative CVD processes. As can be appreciated, such purity can also allow the monomers to form‘clean’ polymerized coatings substantially free of residual impurities.

[0039] Additionally, polymerized 1,1 -di substituted alkene compounds can exhibit excellent mechanical properties including chemical and/or water resistance, chemical and/or water affinity, excellent adhesion properties, and can tolerate modifications to adjust microscale and macroscale properties of the finished coating. In certain embodiments, at least one of the reactive monomers can be selected from a 1,1- disubstituted alkene monomer having fluorinated moieties allowing for the formation of a fluorinated polymeric thin film that is oleophobic and has low friction.

[0040] 1,1 -disubstituted alkene compounds are also beneficial reactive monomers because they can be stable in both liquid and vaporized states and can remain non-reactive with any co- precursors and components of an iCVD coating system. As can be appreciated, both liquid and vapor phase stability are important to an iCVD coating process. For example, stability of the monomers in a liquid state can influence the shelf life of the monomers while stability in the vapor state can influence the conditions necessary for deposition as well as the properties of the polymeric film. Specifically, vapor phase stability can influence the molecular weight and polydispersity of the polymeric film. 1,1 -disubstituted alkene monomers can generally exhibit a long shelf life providing enhanced flexibility to iCVD processes.

[0041] In certain embodiments, stabilizers can be included to improve the stability of the 1,1- disubstituted alkene monomers when in the liquid state and/or the vapor state. Stabilizers can improve the shelf life, prevent spontaneous polymerization, and can improve stability during vaporization. Liquid phase stabilizers can generally be selected from anionic polymerization inhibitors such as methanesulfonic acid (“MSA”) and free-radical stabilizers such as 4- methoxyphenol or mono methyl ether of hydroquinone (“MeHQ”). Vapor phase stabilizers can be selected from at least acidic vapor phase stabilizers such as sulfur dioxide and trifluoroacetic acid (“TFA”). Additional details about suitable stabilizers for 1,1- disubstituted alkene monomers are disclosed in U.S. Patent Nos. 6,458,956; 8,609,885; and 8,884,051 each incorporated by reference herein. Generally, the selection and quantity of stabilizers included with the monomer, or system, can balance the stabilizing effects of the stabilizers against any detriments caused by the presence of impurities in the monomer and polymerized product. In certain embodiments, the quantity and selection of stabilizers can also be varied to influence the microscale properties such as the molecular weight and polydispersity of the polymerized films.

[0042] The iCVD processes described herein can involve polymerization of a vaporized 1,1- di substituted alkene reactive monomer in situ in the vapor phase or, alternatively, at the surface of a substrate in a surface synthesis process. Polymerization of the reactive monomers can occur by reaction of the one or more 1,1 -di substituted alkene monomers with suitable polymerization initiators.

[0043] As will be appreciated, a wide variety of polymerization initiators can initiate polymerization of 1,1 -di substituted alkene reactive monomers. Generally, 1,1 -di substituted alkenes and compositions including such 1,1 -di substituted alkenes can undergo anionic polymerization when exposed to basic initiators. Details of suitable polymerization activators and methods of initiating polymerization of 1,1 -di substituted alkene compositions are disclosed in U.S. Patent No. 9,181,365 which is incorporated herein by reference in its entirety.

[0044] Examples of suitable polymerization initiators which can initiate polymerization of 1,1- disubstituted alkene reactive monomers can include weak anionic compounds {i.e., metal carboxylates, sodium benzoate, and metal halides) and neutral nucleophiles (i.e., secondary and tertiary amines and phosphines). Alternatively, free radical initiators can be used to initiate free radical polymerization. Examples of suitable polymerization initiators can include sodium acetate; potassium acetate; acid salts of sodium, potassium, lithium, copper, and cobalt; tetrabutyl ammonium fluoride, chloride, and hydroxide; secondary or tertiary amines; salts of polymer bound acids; benzoate salts ( e.g ., sodium benzoate; potassium benzoate); 2,4- pentanedionate salts; sorbate salts; propionate salts; secondary aliphatic amines; piperidine, piperazine, N-methylpiperazine, dibutylamine, morpholine, diethylamine, pyridine, tri- ethylamine, tripropylamine, triethylenediamine, N,N-dimethylpiperazine; salts of amines with organic monocarboxylic acids; piperidine acetate; guanidines, such as tetramethyl guanidine, metal salts of a lower monocarboxylic acid; copper(II) acetate, cupric acetate monohydrate, potassium acetate, zinc acetate, zinc chloroacetate, magnesium chloroacetate, magnesium acetate; salts of acid containing polymers; salts of polyacrylic acid co-polymers, and pigments having a basic character. Compounds having basic character can be one or more amines or polyamines. For example, compounds having basic character can be one or more polyalkyleneimines, such as polyethylenimines.

[0045] As can be appreciated, certain substrates can also inherently act as a polymerization initiator and initiate polymerization of a 1,1 -di substituted alkene monomer. For example, basic glass substrates can initiate polymerization of a vaporized 1,1 -di substituted alkene monomer without requiring the addition of a separate polymerization initiator. As can be appreciated, a variety of other substrates can also inherently initiate polymerization of a 1,1 -di substituted monomer including, for example, plastics such as certain polycarbonate and acrylonitrile butadiene styrene plastics.

[0046] As can be further appreciated, substrates can also, or alternatively, be modified to act as an inherent polymerization activator in certain embodiments. For example, polymerization initiators can be incorporated into a substrate as disclosed in U.S. Patent App. Pub. No. 2015/0210894, which is hereby incorporated herein by reference.

[0047] In certain embodiments, polymerization can also be initiated using non-chemical reaction initiators. For example, radiation or electron beams can be used to initiate polymerization of a 1,1 -di substituted monomer. Advantageously, electricity can also be used to initiate polymerization of 1, l-di substituted alkene monomers as described in U.S. Patent No. 9,217,098 which is hereby incorporated by reference herein.

[0048] Suitable polymerization initiators can be monofunctional, difunctional, trifunctional, or multifunctional in certain embodiments. As used herein, functionality of the polymerization initiator indicates the number of initiating sites included on each polymerization initiator. As can be appreciated, functionality of a polymerization initiator can influence the relative amounts of chain entanglement and crosslinking experienced by a reactive monomer. Functionality can also influence the relative quantity of polymerization initiator necessary for an iCYD process. [0049] In certain embodiments, liquid polymerization initiators can be preferred. As can be appreciated, liquid polymerization initiators can be beneficial because such initiators can be free of solvent and can produce polymeric thin films of extremely high purity. For example, in certain embodiments, a liquid tertiary amine or a liquid heterocyclic amine such as 1,8- diazabicyclo[5.4.0]undec-7-ene (“DBU”) and l,5-diazabicyclo[4.3.0]non-5-ene (“DBN”) can be used as a liquid polymerization initiator.

[0050] Liquid polymerization initiators such as DBU and DBN can also be desirable because such initiators can be volatilized and initiate polymerization in situ in the vapor phase. Sometimes referred to as simultaneous vapor deposition, in situ polymerization of the reactive monomer can be useful to form polymeric thin films of high purity and excellent adhesion on a wide variety of substrates in a single step process. In such embodiments, vaporized reactive monomer and vaporized polymerization initiator can be mixed and initiate polymerization before being depositing on a substrate. A schematic diagram of one illustrative iCVD system for simultaneous vapor deposition is depicted in FIG. 1.

[0051] As depicted in FIG. 1, a simultaneous vapor deposition system 100 can include a plurality of inlet ports (la, lb) for injection of vaporized compounds. In FIG. 1, inlet port la can inject a reactive monomer such as a 1,1 -di substituted alkene monomer and inlet port lb can inject a polymerization initiator such as vaporized DBU. As can be appreciated, additional inlet ports (not depicted) can be included in certain embodiments for the injection of additional vapors or additives. Vapors injected into system 100 can mix in situ and initiate polymerization in chamber 5. After polymerization of the reactive monomer is initiated, the polymerizing monomer can deposit on article 10 (e.g., a substrate).

[0052] The reactive monomer and the polymerization initiator can be vaporized in any suitable fashion. For example, the reactive monomer and the polymerization initiator can independently be heated to their respective boiling points to form a vapor suitable for injection into system 100. In certain embodiments, it can be advantageous to vaporize the reactive monomer and the polymerization initiator under vacuum. Vaporization under a vacuum can reduce the boiling point temperature leading to increased stability of the vaporized compounds, lower energy requirements, and less heat transfer to the substrate upon deposition. In other certain embodiments, a reactive monomer and polymerization initiator can alternatively be aerosolized. For example, conventional aerosol canisters can be used in certain embodiments.

[0053] As can be appreciated, the selection of a vaporization or an aerosolization system can be selected based on the desired properties of the coatings. For example, a vaporization system can produce uniform coatings because the reactive monomer and/or reaction initiator can be evenly distributed throughout the system. Aerosolization systems, in contrast, allow for improved control because spraying of the reactive monomer and/or reaction initiator can be selectively controlled.

[0054] As can be appreciated, many variations to simultaneous vapor deposition systems are possible. For example, the system 100 depicted in FIG. 1 further includes a perforated plate 15 to support the article 10 and a second chamber 20. In FIG. 1, the second chamber 20 is under vacuum and includes an outlet port 25 to remove excess vapors and create a vacuum in chambers 5 and 20. However, in other systems (not depicted), only a single chamber 5 can be present. In such embodiments, the reactive monomer and polymerization initiator can be vaporized at standard atmospheric pressure and the system 100 can include an outlet port (not depicted) in chamber 5 to equilibrate pressure with the surrounding environment. As can be appreciated, an iCVD system can also include a number of other conventional components including flow controllers, vacuum controllers, temperature controllers, thermocouples, valves, gauges, sensors, condensers, controls, and exhaust systems.

[0055] In certain embodiments, additional inlet ports can be included in simultaneous vapor deposition system to modify an iCVD process. For example, an additional reactive monomer, such as an additional l,l-disubstituted alkene monomer, can simultaneously be injected in certain embodiments. The use of multiple 1,1 -di substituted alkene monomers can be useful to tailor the properties of the polymeric film deposited on a substrate. For example, additional 1,1- disubstituted alkene monomers can enhance the properties of the polymeric film by forming polymers having a different glass transition temperature or different tackiness than the first 1,1- disubstituted alkene monomer. Additional benefits and examples disclosing the use multiple 1,1- disubstituted alkene compounds are disclosed in U.S. Patent No. 9,315,592 and PCT Patent App. Pub. No. WO 2016/040261 each of which are incorporated herein by reference. [0056] Alternatively, additional inlet ports can be included to inject one or more additives to the system. Generally, any additive that can be vaporized, or aerosolized, can be injected into an iCVD system including mechanical support additives, conductive additives, and additives that chemically interact with the reactive monomers. For example, in certain embodiments, crosslinking agents or polymerization chain growth terminators can be injected to modify the amount of crosslinking or molecular weight of the 1,1 -di substituted alkene monomers.

[0057] In certain embodiments, it can be useful to utilize difunctional or multifunctional 1,1- disubstituted alkene monomers. As can be appreciated, the use of difunctional or multifunctional monomers can increase the amount of crosslinking between the monomers and can produce different polymer properties. For example, the use of multifunctional monomers can improve the durability of coatings formed from the iCVD process and can improve the resistance of the coatings to degradation. In certain embodiments, about 5%, by weight, or more of the 1,1- disubstituted alkene monomers can be difunctional or multifunctional monomers. In certain embodiments, about 10%, by weight, or more of the disubstituted alkene monomers can be difunctional or multifunctional.

[0058] As can be appreciated, it can also be advantageous in certain embodiments to minimize the quantity of difunctional or multifunctional monomers. In certain embodiments, about 30%, by weight, or less of the 1,1 -disubstituted alkene monomers can be difunctional or multifunctional. In certain embodiments, about 20%, by weight, or less of the 1,1 -disubstituted alkene monomers can be difunctional or multifunctional.

[0059] As can be appreciated, the relative timing and quantities of vapors and additives injected into a system can be varied in certain embodiments. For example, relatively less polymerization initiator can be injected in certain embodiments to favor relatively longer polymer chain growth with less crosslinking in certain embodiments. In certain embodiments, suitable gas flow rates for the reactive monomers, initiator, and additives can vary from about 20 cm 3 /min to about 100 cm 3 /min. In certain embodiments, suitable liquid flow rates can vary from about 100 pL/min to about 5,000 pL/min. [0060] In certain embodiments, the amount of polymerization can also be varied by modifying the temperature of the reactive monomer and/or the reaction initiator. As can be appreciated, heating the reactive monomer or the reaction initiator can increase the rate of polymerization.

[0061] Additionally, or alternatively, injection of a polymerization initiator can be terminated in certain embodiments after a set period of time while still supplying additional reactive monomer. As can be appreciated, certain 1,1 -di substituted alkene monomers can undergo living anionic polymerization which will continue to polymerize additional reactive monomer even in the absence of any polymerization initiators.

[0062] In certain embodiments, simultaneous vapor deposition can be a substantially one-step process and can be used as a continuous coating process for both small and large volumes of coatings.

[0063] Alternatively, in certain embodiments, a polymerization initiator can be applied to a substrate of an article in a solid or liquid form. In such surface synthesis embodiments, vaporized 1,1 -di substituted alkene monomer can polymerize upon contact with the liquid or solid polymerization initiator on the substrate to form a polymeric film. As can be appreciated, any of the additives suitable for a simultaneous vapor deposition process can be used in a surface synthesis process.

[0064] Surface synthesis processes can generally be less preferred than simultaneous vapor deposition processes as a consequence of the surface synthesis process being a two-step process requiring (1) application of the polymerization initiator and (2) subsequent deposition of the vaporized reactive monomer. Additionally, the presence of the polymerization initiator on the substrate may cause polymeric film adhesion issues not found in simultaneous vapor deposition processes.

[0065] However, surface synthesis processes can also exhibit several advantages over simultaneous vapor deposition processes. For example, deposition of a polymeric film can be easily limited to specific portions of a substrate through selective application of the polymerization initiator. As can be appreciated, multiple polymeric films exhibiting different qualities can be applied to a substrate using selective placement of polymerization initiator and multiple surface synthesis processes. Although similar results are possible using a simultaneous vapor deposition, protective masking or the like are required.

[0066] As can be appreciated, both simultaneous vapor deposition processes and surface synthesis processes can form polymeric films that are capable of initiating further polymerization as a consequence of certain 1,1 -di substituted alkene monomers undergoing living anionic polymerization. In such embodiments, any additional reactive monomers depositing on a polymeric film still undergoing living anionic polymerization will begin polymerizing on top of the initial film without requiring the injection of any additional polymerization initiators. As can be appreciated, unique coatings can be applied to a substrate by temporarily pausing the addition of monomer and then supplying additional reactive monomer.

[0067] The additional reactive monomers can include 1,1 -di substituted alkene monomers different than the 1,1 -di substituted alkene monomers of the initial polymeric film, 1,1- disubstituted alkene monomers identical to the monomers of the initial polymeric film, and any other reactive monomer that can be initiated by living free radical polymerization process. FIG. 2 depicts a side view of a substrate 200 including first and second polymeric films 225, 250. The second polymeric film 250 of FIG. 2 can be initiated upon contact with the first polymeric film 225 and can be formed of different 1,1 -di substituted alkene reactive monomers.

[0068] As can be appreciated, a second polymeric film can also be applied through a suitable iCVD process. For example, additional reaction initiators can be applied to the previously coated substrate or an additional reaction initiator can be vaporized in certain embodiments.

[0069] As can be appreciated, the use of two polymeric films can be useful to tailor the properties created by the iCVD process. For example, a first polymeric film can be configured to have strong adhesion to a substrate while a second polymeric film can be configured to have a large amount of crosslinking to provide increased durability to the substrate. As can be appreciated, additional properties can be provided by including additional polymeric films over the second polymeric film.

[0070] The iCVD processes described herein can provide a polymeric film coating to a wide variety of substrates including organic, inorganic, and composite substrates. As can be appreciated, iCVD processes can provide polymeric films to a wide variety of substrates because the reactive monomer is initiated before contacting the substrate and because adhesion can occur through either mechanical or chemical bonding. As can be appreciated, adhesion to substrates can also be tailored by selection of the reactive monomer and polymerization initiator. For example, a blend of multiple 1,1- disubstituted alkene monomers each having a different glass transition temperature can be selected when a substrate is relatively rough to ensure there is strong mechanical adhesion caused by tacky polymers.

[0071] Additionally, conventional surface preparation methods can optionally be used to prepare a substrate prior to coating with the iCVD processes described herein. Surface modification using, for example, sand blasting, chemical wipes, solvents, and the like can be useful to improve surface adhesion by cleaning the substrate, exposing chemically reactive sites, or by modifying the surface roughness. Generally, surface preparation can be performed with little to no effect on the remaining steps in an iCVD process.

[0072] Other modifications to the iCVD process are also possible. For example, an iCVD process described herein can be combined with a conventional CVD process in certain embodiments. In such embodiments, a thermal or energy-assisted CVD process can simultaneously be operated in conjunction with an iCVD process described herein. As can be appreciated, combination of such CVD processes can allow for the deposition and polymerization of additional monomers such as acrylates, siloxanes, acrylamides, and dienes with the reactive 1,1 -disubstituted alkene monomers of the iCVD process. In certain embodiments, the additional CVD process can include anionic or free radical polymerizable materials which can be polymerized by the processes used to initiate, or continue, curing of the 1,1 -disubstituted alkene compounds.

Examples

[0073] Aerosol Sprays

[0074] Examples 1 to 3 evaluated the use of aerosol sprays to provide vaporized 1,1- disubstituted alkene materials. In each of Examples 1 to 3, a polymerization initiator and one or more 1,1 -disubstituted alkene reactive monomers were successively deposited onto a cotton-like material using respective aerosol canisters. Each of Examples 1 to 3 was repeated multiple times to ensure repeatability. Table 1 depicts the materials used in each of Examples 1 and 2.

TABLE 1

[0075] Examples 1 and 2 were evaluated by applying a droplet of water to the coated cotton-like material as well as an untreated control sample. In both Example 1 and 2, the untreated control sample immediately absorbed the droplet of water.

[0076] In Example 1, the water droplet beaded on the surface of the coated material and evaporated overnight without any observable absorption into the cotton-like material. Additionally, the coated cotton-like material retained its flexibility and breathability suggesting formation of a functional microscale film of the polymerized 1, l-di substituted material.

[0077] Example 2 achieved similar results to Example 1 with the addition observation of tack. Specifically, Example 2 exhibited a tacky feeling in addition to the beading of the water droplet and retention of flexibility and breathability observed in Example 1. The tacky feel of Example 2 is believed to be caused by poly(HMMM) which is a tacky polymer.

[0078] Example 3 evaluated the ability of previous layers to initiate additional layers of reactive monomer. In Example 3, the process of Example 1 was repeated with identical materials and conditions to form a layer of polymerized DEMM on a cotton-like material. Subsequently, an aerosol canister was then used to apply an additional layer of HMMM to the previously-coated cotton-like material. No additional polymerization initiator was applied to initiate the HMMM.

[0079] Example 3 exhibited good results including beading of a droplet of water, retention of flexibility and breathability, as well as the tackiness expected from a layer of poly(HMMM).

[0080] Thermal Vaporization of Components

[0081] Example 4 evaluated the ability to deposit a 1, l-di substituted alkene monomer using vaporization of the reactive monomer. The test setup of Example 4 is depicted in FIG. 3. In Example 4, 10 g of a DEMM solution was provided in a 100 mL 3 neck round bottom flask. The DEMM solution included 1,000 ppm of MeHQ and 100 ppm of MSA as stabilizers to improve the stability of DEMM. Evaporation of the monomer was achieved by heating the DEMM solution to a temperature of about 145 °C under a vigorous nitrogen purge. DEMM vapor was then directed to a piece of cold rolled steel previously treated with a 0.1 weight percent tetram ethyl guanidine solution in ethanol.

[0082] The cold-rolled steel substrate exhibited visible signs of coating after exposure to the DEMM vapor. Samples of the coating were evaluated using Gel Permeation Chromatography (“GPC”) and Differential Scanning Calorimetry (“DSC”). The evaluated coating material of Example 4 had a number average molecular weight (“Mn”) of 10,393, a weight average molecular weight (“Mw”) of 15,950, and a polydispersity index of 1.5. The glass transition temperature (“Tg”) of Example 4 was about 30 °C to about 34 °C.

[0083] Example 5 further evaluated the ability to use a vaporized polymerization initiator for a simultaneous vapor deposition. The experimental test setup of Example 5 is depicted in FIG. 4 and includes two 3 neck round bottom flasks and a y-shaped glass connector to mix the vaporous reactive monomer and polymerization initiator. In Example 4, the reactive monomer was DEMM which was vaporized under a vigorous nitrogen purge at the boiling point of DEMM (about 140 °C to about 145 °C) and the polymerization initiator was l,8-diazabicyclo[5.4.0]undec-7-ene (“DBU”) vaporized under a vigorous nitrogen purge at the boiling point of DBU (about 85 °C to about 87 °C). After combination of the vapors, the initiated chemical vapor stream was directed to a substrate where the initiated monomers deposited on a substrate to form a coating. [0084] The coating of Example 5 was evaluated using GPC and DSC. The evaluated coating material of Example 5 had a number average molecular weight (“Mn”) of 105,901, a weight average molecular weight (“Mw”) of 239,659, and a polydispersity index of 2.3. The Tg of Example 5 was about 30 °C to about 34 °C.

[0085] Vacuum Vaporization of Components

[0086] Examples 6 and 7 evaluated the ability to vaporize the components at lower temperatures by using a vacuum to reduce the boiling point of the reactive monomer and the polymerization initiator. Example 6, for example, is similar to Example 4 but was performed under a vacuum pressure of about 3 mm Hg. The reduced pressure of 3 mm HG reduced the boiling point of DEMM to about 75 °C to about 90 °C. The experimental setup of Example 6 is depicted in FIG. 5. The reactive monomer vapor was not collected and was instead directed to an aluminum foil substrate pretreated with a solution of 0.1 weight percent tetramethylguanidine in ethanol to produce a polymeric coating.

[0087] The polymerized coating of Example 6 was evaluated using GPC and DSC. The evaluated coating material of Example 6 had a number average molecular weight (“Mn”) of 129,111, a weight average molecular weight (“Mw”) of 336,673, and a polydispersity index of 2.6. The Tg of Example 6 was about 30 °C to about 34 °C.

[0088] Example 7 demonstrated that both a reactive monomer, DEMM, and a polymerization initiator, DBET, could be vaporized under vacuum conditions. For Example, 7, DEMM was boiled at about 75 °C to about 90 °C and DBET was boiled at about 55 °C to about 70 °C by holding both to a vacuum pressure of about 3 mmHg. The respective vapors were then combined in Zone 1 before coating an aluminum foil substrate as depicted in FIG. 6.

[0089] The resulting coating of Example 6 was evaluated using GPC and DSC. The evaluated coating material of Example 6 had a number average molecular weight (“Mn”) of 113,874, a weight average molecular weight (“Mw”) of 265,993, and a polydispersity index of 2.3. The Tg of Example 7 was about 30 °C to about 34 °C.

[0090] Table 1 depicts the number average molecular weight (“Mn”), weight average molecular weight (“Mw”), and polydispersity of each of Examples 4 to 7. TABLE 2

[0091] As depicted by Table 2, several desirable molecular weight builds have been demonstrated. Table 2 additionally illustrates that the molecular weight build can be influenced by selection and inclusion of stabilizers in the reactive monomer (e.g., the anionic and free radical polymerization stabilizers of Example 4 lowered the molecular weight build but produced more uniform polymers) as well as by relative concentration of polymerization initiators to reactive monomer.

[0092] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value.

[0093] It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. [0094] Every document cited herein, including any cross-referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests, or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in the document shall govern.

[0095] The foregoing description of embodiments and examples has been presented for purposes of description. It is not intended to be exhaustive or limiting to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed and others will be understood by those skilled in the art. The embodiments were chosen and described for illustration of various embodiments. The scope is, of course, not limited to the examples or embodiments set forth herein, but can be employed in any number of applications and equivalent articles by those of ordinary skill in the art. Rather it is hereby intended the scope be defined by the claims appended hereto.

[0096] It should be understood that certain aspects, features, structures, or characteristics of the various embodiments can be interchanged in whole or in part. Reference to certain embodiments mean that a particular aspect, feature, structure, or characteristic described in connection with certain embodiments can be included in at least one embodiment and may be interchanged with certain other embodiments. The appearances of the phrase“in certain embodiments” in various places in specification are not necessarily all referring to the same embodiment, nor are certain embodiments necessarily mutually exclusive of other certain embodiments. It should also be understood that the steps of the methods set forth herein are not necessarily required to be performed in the orders described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps can be included in such methods, and certain steps may be omitted or combined, in methods consistent with certain embodiments.