METHOD OF MAKING CARBAMATE FUNCTIONAL MATERIALS

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. Application No. 11/854,636, filed on September 13, 2007. The disclosure of the above application is incorporated herein by reference.

FIELD

[0002] The present disclosure relates to methods of making materials, including oligomers and polymers, having carbamate groups and coating compositions containing such materials.

BACKGROUND

[0003] The statements in this section provide background information in relation to the present disclosure and may or may not constitute prior art.

[0004] Clearcoat-basecoat composite coatings are widely used in the coatings art and are notable for desirable gloss, depth of color, distinctness of image and/or special metallic effects. Composite systems are particularly utilized by the automotive industry to achieve advantageous visual effects, especially a high degree of clarity. However, a high degree of clarity in the clearcoat makes it easier to observe defects, among which are defects from degradation by environmental effects on the coating.

[0005] The clearcoat layer also provides protection of the substrate and lower coating layers from environmental degradation. Curable coating compositions utilizing carbamate-functional resins have been used in coatings and include those described, for example, in U.S. Patent Nos. 5,693,724,

5,693,723, 5,639,828, 5,512,639, 5,508,379, 5,451 ,656, 5,356,669, 5,336,566, and 5,532,061 , each of which is incorporated herein by reference. These coatings can provide significant improvements in resistance to environmental etch over other coatings using other compositions, such as hydroxy-functional acrylic/melamine coating compositions.

[0006] Carbamate functionality may be incorporated by 'trans- carbamating ¹ hydroxyl-functional acrylic resins with hydroxy carbamate compounds, as described in U.S. Patent Nos. 5,693,724, 5,693,723, 5,639,828, 5,512,639, 5,508,379, 5,451 ,656, 5,356,669, 5,336,566, 5,532,061 and 6,531 ,560. The reaction step is a time-consuming process, however, and produces side products like methanol that, along with other solvents used for the reaction medium, must be removed somehow. Moreover, undesirable side reactions may take place to some degree.

[0007] Vinyl polymers prepared from acrylates and methacrylates have been extensively used for topcoats such as automotive clearcoats and basecoats because of the excellent balance of properties they provide, forming coatings that are tough, durable, and glossy. Derango et al., "The Lipase- Catalyzed Synthesis of Carbamoyloxyethyl Methacrylate," Biotechnology Letters, Vol. 16, No. 3 (March 1994) pp. 241-46 describes using lipase as a catalyst for transesterification of 2-hydroxyethylcarbamate with vinyl methacrylate to prepare carbamoyloxyethyl methacrylate. Dietsche et al., U.S. Patent 7,164,037 teaches an enzymatic preparation of (meth)acrylic esters containing urethane groups and their use in a radiation-curable composition, the reaction producing as a byproduct a low boiling point alcohol.

SUMMARY

[0008] Compositions and methods of making a carbamate functional material and preparing coatings containing carbamate-functional materials include transesterification of a material having an ester group with a hydroxy compound containing a carbamate group. The material having an ester group typically has a molecular weight greater than about 500 g/mol and can be an oligomer, polymer, and/or an ester of a fatty acid. The transesterification reaction is catalyzed by a biocatalyst, which can include an enzyme such as lipase. The carbamate functional reaction products are used to make coating compositions.

[0009] The material having an ester group may include a polymer, oligomer, or crosslinkable compound that has a plurality of ester groups. The

ester group can comprise a pendant or terminal group on the material. For example, where the material is a polymer, one or more units forming the backbone chain may have an ester side group and/or the terminal units of the backbone chain may have an ester group. Polymers include vinyl polymers, acrylic polymers, polyesters, polyurethanes, mixtures thereof, and copolymers thereof and typically have molecular weights greater than about 1500 g/mol. Oligomehc materials having an ester group include at least two units which may be the same or different and typically have molecular weights of about 500 to 1500 g/mol. In some cases, the oligomers may be polymerized to form polymers or copolymers. Upon transesterification, the material having an ester group may release an alcohol, such as various alkanols having 1 to about 18 carbons, or where the ester includes an ethenoxy group, vinyl alcohol is produced.

[0010] The hydroxy compound having a carbamate group is used to add carbamate functionality to the material having an ester group. For example, the hydroxy compound having a carbamate can be a hydroxyalkyl carbamate, having linear and/or cyclic alkyl portions or the hydroxy compound having a carbamate can be a hydroxyaryl carbamate having an aromatic portion in addition to the hydroxy and carbamate groups. The carbamate group of the hydroxy compound may be a primary carbamate (i.e., -0(CO)NH ₂ ) or may be substituted (i.e., -0(CO)NHR or -0(CO)NR ₂ ). Primary carbamates are usually preferred for their improved rates of reaction with aminoplast crosslinkers.

[0011] The biocatalyst is operable to carry out a transesterification reaction between the material having an ester group and the hydroxy compound having a carbamate group to thereby produce the carbamate functional material. Suitable biocatalysts include microbial organisms, fermentation media, and/or isolated enzymes purified from microbial organisms or fermentation media. In some cases, the biocatalyst is an enzyme such as a lipase. The enzyme may form an acyl-enzyme intermediate with the material having an ester group which subsequently reacts with the hydroxy compound having a carbamate group to produce the carbamate functional material. The biocatalyst may be affixed to a solid support.

[0012] The present compositions and methods provide several benefits and advantages. In particular, the present methods are used to form a carbamate functional material from a material having an ester group that has a molecular weight greater than about 500 g/mol, as compared to other methods that add carbamate functionality to monomeric or low molecular weight (< 500 g/mol) materials. By using a material having an ester group with a molecular weight greater than about 500 g/mol, the present methods may employ a reaction medium containing organic solvent since many polymers, oligomers, and esters of fatty acids are more soluble in organic solvents. Moreover, hydroxy compounds having carbamate functionality are often not very soluble in organic solvents. However, polymerization of many monomers (e.g., polymerization of acrylate monomers to form acrylic resins) is typically performed in organic solvents. Thus, the present reactions may be conducted in organic solvents, including hydrophobic organic solvents, providing a better reaction medium for solubilizing both the material having an ester group and the hydroxy compound having carbamate functionality.

[0013] Using a material having an ester group for transesterification provides further advantages compared to using monomers having an ester group. Monomers are typically reactive compounds that can have stability and storage issues and can in some cases be classified as toxic materials. In addition, the availability and cost of monomers can be prohibitive. By using a material having an ester group, where the material is a polymer, oligomer, or ester of a fatty acid, the present methods can employ more stable, less toxic, and less costly components that have a greater storage life. [0014] Finally, the present compositions and methods allow addition of carbamate groups to large ester compounds, such as fatty acid esters that can include biomass-derived compounds including fatty acid methyl esters. For example, fatty acid methyl esters produced by alkali catalyzed reaction between fats or fatty acids and methanol may be used. These compounds can be derived from renewable resources, for example, biodiesel formulations are often composed of fatty acid methyl esters, usually obtained from vegetable oils by transesterification. Thus, the present compositions and methods afford a means

to incorporate carbamate functionality into biomass-derived compounds for use in coating compositions.

[0015] "A" and "an" as used herein indicate "at least one" of the item is present; a plurality of such items may be present, when possible. "About" when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by "about" is not otherwise understood in the art with this ordinary meaning, then "about" as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range.

[0016] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present invention.

DETAILED DESCRIPTION [0017] Compositions and methods for making a carbamate functional material include reacting a material having an ester group and a hydroxy compound having a carbamate group. The reaction employs a biocatalyst capable of performing a transesterification reaction in order to produce the carbamate functional material along with an alcohol byproduct. The material having an ester group has a molecular weight of at least about 500 g/mol. [0018] The material having an ester group can be an oligomer, polymer, or fatty acid ester. Oligomers are polymers having relatively few monomer units; generally, an oligomer has ten or fewer polymerized monomer units. Polymers are generally larger than oligomers and typically have more than ten polymerized monomer units and may include hundreds or thousands or more polymerized monomer units. Polymeric materials having an ester group may therefore have molecular weights on the order of several thousand grams

per mol, tens of thousands of grams per mol, hundreds of thousands of grams per mol, or even greater.

[0019] In some embodiments, oligomers and polymers may be homogeneous or heterogeneous materials; for example, two or more different monomers may be used to form a heterogeneous oligomer or polymer. Polymerization of two different monomers forms what is typically referred to as a copolymer. Oligomers may be subsequently polymerized to form polymers and different oligomers and/or oligomers formed from different monomers may be used to form polymers having ordered or random block units. Oligomeric and polymeric materials may have linear or branched structures and may themselves be hyperbranched or may be used to form hyperbranched structures, such as dendrimers.

[0020] The material having an ester group includes at least one ester group and may have a plurality of ester groups. The ester group(s) may be a pendant or terminal ester group on the material and both pendant and terminal ester groups may be present. For example, where the material having an ester group is a fatty acid ester, the fatty acid ester may be a fatty acid diester, or where the material having an ester group is a polymer, the polymer may have dozens, hundreds, or thousands or more pendant ester groups. [0021] In some embodiments, the material having an ester group has the formula (1 ):

wherein, R ¹ is an oligomeric or polymeric group; and R ² is a saturated C1-C1 ₈ alkyl group or unsaturated C ₂ -Ci ₈ alkyl group. In some embodiments, R ¹ is an oligomeric or polymeric group; and R ² is CrCi ₈ alkyl; C ₂ -Ci ₈ alkyl uninterrupted or interrupted by one or more oxygen and/or sulfur atoms and/or by one or more substituted or unsubstituted imino groups; C ₂ -Ci ₈ alkenyl; C ₆ -Ci ₂ aryl; C ₅ -Ci ₂ cycloalkyl; five- to six-membered heterocycle containing oxygen, nitrogen and/or sulfur atoms; or a group of the formula -[Xj] _k -H, where k is a number from 1 to 50, and Xj for i=1 to k selected independently from the group consisting of -CH ₂ - CH ₂ -O-, -CH ₂ -CH ₂ -N(H)-, -CH ₂ -CH ₂ -CH ₂ -N(H)- -CH ₂ -CH(NH ₂ )- -CH ₂ -

CH(NHCHO)-, -CH ₂ -CH(CH ₃ )-O- -CH(CH ₃ )-CH ₂ -O-, -CH ₂ -C(CHs) ₂ -O-, - C(CH ₃ ) ₂ — CH ₂ -O-, -CH ₂ -CH ₂ -CH ₂ -O-, -CH ₂ -CH ₂ -CH ₂ -CH ₂ -O-, -CH ₂ - CHVin-O- -CHVJn-CH ₂ -O-, -CH ₂ -CHPh-O-, and -CHPh-CH ₂ -O-, where Ph stands for phenyl and Vin stands for vinyl. [0022] Reaction of the material having an ester group with the hydroxy compound having a carbamate group can produce an alcohol byproduct based on the R ² group of formula (1 ). For example, where R ² is Ci (i.e., a methyl group) the subsequent alcohol byproduct is methanol.

[0023] In some embodiments, the material having an ester group has the formula (2):

in which n is 1 , m is 1 or an integer greater than 1 , each R is independently H or an alkyl group of 1 to 4 carbon atoms, and X is an m-valent material that is polymer, oligomer, or fatty acid ester. In this case, the unsaturated alcohol byproduct produced by reaction with the hydroxy compound having a carbamate group may tautomerize to the corresponding aldehyde or ketone, thereby reducing or eliminating the reverse reaction. The result is that the reaction equilibrium is shifted toward complete conversion of the material having an ester group to the carbamate functional material. Where each R in formula (2) is H, the material having an ester group can have the formula (3):

wherein, R ¹ is an oligomeric or polymeric material. In this case, the ethenoxy leaving group forms vinyl alcohol that can tautomerize to acetaldehyde. In addition to tautomerization, the alcohol by-product may be removed either by distillation at atmospheric pressure or using vacuum, or by using osmotic filters to remove the alcohol by-product.

[0024] In some embodiments, where the material having an ester group is a polymer, the polymer can be a vinyl polymer, acrylic polymer,

polyester, polyurethane, mixtures thereof, or copolymers thereof. Acrylic polymers include those of methyl, ethyl and/or propyl (meth)acrylate and polymers and copolymers formed using other known acrylic monomers. Methanol, ethanol and/or propanol may be used to incorporate ester groups into polyesters or polyethers. Carboxyl-functional methyl to propyl esters may be used to react with epoxide-functional polymers, oligomers and materials. Hydroxy-functional methyl to propyl esters may be used to incorporate ester groups into urethane polymers, oligomers and materials. The material having an ester group may also be formed by reacting a polyisocyanate and an ethenyl ester of a hydroxyalkanoic acid.

[0025] In some embodiments, the material having an ester group may be a polymer, such as a vinyl polymer, a polyester, a polyurethane, or a polyether. A vinyl polymer having a pendent ethenoxy group may be prepared by the free radical polymerization of a material containing active double bonds and non-activated double bonds. An example of such a material is vinyl methacrylate. Examples of suitable co-monomers include, without limitation, α,β-ethylenically unsaturated monocarboxylic acids containing 3 to 5 carbon atoms such as acrylic, methacrylic, and crotonic acids and the esters of those acids; α,β-ethylenically unsaturated dicarboxylic acids containing 4 to 6 carbon atoms and the anhydrides, monoesters, and diesters of those acids; vinyl esters, vinyl ethers, vinyl ketones, and aromatic or heterocyclic aliphatic vinyl compounds.

[0026] Representative examples of suitable esters of acrylic, methacrylic, and crotonic acids include, without limitation, those esters from reaction with saturated aliphatic and cycloaliphatic alcohols containing 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert- butyl, 2-ethylhexyl, lauryl, stearyl, cyclohexyl, trimethylcyclohexyl, tetrahydrofurfuryl, stearyl, sulfoethyl, and isobornyl acrylates, methacrylates, and crotonates. Representative examples of other ethylenically unsaturated polymerizable monomers include, without limitation, such compounds as fumaric, maleic, and itaconic anhydrides, monoesters, and diesters with alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, and tert-

butanol. Representative examples of polymerization vinyl monomers include, without limitation, such compounds as vinyl acetate, vinyl propionate, vinyl ethers such as vinyl ethyl ether, vinyl and vinylidene halides, and vinyl ethyl ketone. Representative examples of aromatic or heterocyclic aliphatic vinyl compounds include, without limitation, such compounds as styrene, α-methyl styrene, vinyl toluene, tert-butyl styrene, and 2-vinyl pyrrolidone. The co- monomers may be used in any desired combination to produce desired vinyl or acrylic polymer properties.

[0027] The vinyl polymer may be prepared using conventional techniques, such as by heating the monomers in the presence of a polymerization initiating agent and optionally chain transfer agents. The polymerization is preferably carried out in solution, although it is also possible to polymerize the acrylic polymer in bulk. Suitable polymerization solvents include, without limitation, esters, ketones, ethylene glycol monoalkyl ethers and propylene glycol monoalkyl ethers, alcohols, and aromatic hydrocarbons such as xylene, toluene, and Aromatic 100.

[0028] Typical initiators are organic peroxides such as dialkyl peroxides such as di-tert-butyl peroxide, peroxyesters such as tert-butyl peroctoate and tert-butyl peracetate, peroxydicarbonates, diacyl peroxides, hydroperoxides such as tert-butyl hydroperoxide, and peroxyketals; azo compounds such as 2,2'azobis(2-methylbutanenitrile) and 1 ,1 '- azobis(cyclohexanecarbonitrile); and combinations of these. Typical chain transfer agents are mercaptans such as octyl mercaptan, n- or tert-dodecyl mercaptan; halogenated compounds, thiosalicylic acid, mercaptoacetic acid, mercaptoethanol, and dimeric alpha-methyl styrene.

[0029] The solvent or solvent mixture may be heated to the reaction temperature and the monomers and initiator(s) and optionally chain transfer agent(s) added at a controlled rate over a period of time, typically from about two to about six hours. The polymerization reaction may usually be carried out at temperatures from about 20 ^s C to about 200 ^s C. The reaction may conveniently be done at the temperature at which the solvent or solvent mixture refluxes, although with proper control a temperature below the reflux may be maintained.

The initiator should be chosen to match the temperature at which the reaction is carried out, so that the half-life of the initiator at that temperature should preferably be no more than about thirty minutes, more preferably no more than about five minutes. Additional solvent may be added concurrently. The mixture may be held at the reaction temperature after the additions are completed for a period of time to complete the polymerization. Optionally, additional initiator may be added to ensure complete conversion of monomers to polymer.

[0030] An acrylic polymer having groups may be prepared by taking advantage of the lower reactivity of the vinyl group relative to acrylate or methacrylate groups in addition polymerization, so that polymerization of vinyl (meth)acrylate with other acrylate or methacrylate monomers can be achieved without reaction of the vinyl group of the vinyl (meth)acrylate.

[0031] In some embodiments, the material having an ester group is a polyurethane polymer. Polyurethane polymers may be prepared by reaction of compounds or macromonomers having two hydroxyl groups, for example compounds such as alkylene glycols and polyalkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and neopentyl glycol, 1 ,4-butanediol, 1 ,6-hexanediol, 1 ,4-cyclohexane dimethanol, glycerine, trimethylolpropane, trimethylolethane, pentaerythritol, 2,2,4-trimethyl-1 ,3- pentanediol, fatty acid dimer diols such as PRI POL™ C36 dimer diols from Uniqema (New Castle, DE), hydrogenated bisphenol A, hydroxyalkylated bisphenols, and macromonomers such as polyester diols, with a diisocyanate materials. When the carbmate function material formed from the material having an ester group is to be used in coating composition, such as a topcoat (including basecoat and clearcoat) composition, the diisocyanate is aliphatic, for example isophorone diisocyanate, hexamethylene diisocyanate, or cyclohexamethylene diisocyanate.

[0032] In some embodiments, the polyurethane is prepared in two stages, with an isocyanate-functional prepolymer prepared in the first stage and then capped with a polyhydroxyl compound, such a trimethylolpropane,

pentaerythritol, diethanolamine, and so on. Polyester polymers are prepared by reaction of dihydroxy compounds, such as those already mentioned, and dicarboxylic acids. An ethenoxy group is introduced onto the polyurethane by the reaction of a carboxyl, hydroxyl, oxirane, or cyclic anhydride functional vinyl material. Also included are homopolymers formed from diiisocyanates, such as isocyanurates, uretdiones, and biuretes. These materials may be used "as is" to make oligomers, or further extended to form polymers.

[0033] In some embodiments, the material having an ester group is a polyester polymer. Polyester polymers are prepared by reaction of a compounds or macromonomers having two hydroxyl groups, for example those already mentioned, with a compound or macromonomer having two carboxylic groups or an anhydride group. Dicarboxylic acids or anhydrides of dicarboxylic acids are preferred, but higher functional acid and anhydrides can be used when some branching of the polyester is desired. For the same reason, higher functional polyols may be used. Non-limiting examples of suitable carboxylic acids and anhydrides include those having from about 3 to about 20 carbon atoms. Illustrative examples of suitable compounds include, without limitation, phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, pyromellitic acid, malonic acid, maleic acid, succinic acid, azeleic acid, glutaric acid adipic acid, azelaic acid, 1 ,4- cyclohexanedicarboxylic acid, dodecane-1 ,12-dicarboxylic acid, citric acid, trimellitic acid, and anhydrides thereof. Fatty acid dimers such as PRI POL™ C36 dimer diols from Uniqema (New Castle, DE) may also be used. An ethenoxy group may be introduced onto the polyurethane by copolymerization of mono- or polyhydroxy materials with ethenyl groups such as the ethenyl ester of 3-hydroxypropionic acid, or the ethenyl ester of 3-hydroxy-2-(hydroxymethyl)-2- methylpropanoic acid. A non-limiting, suitable example of a compound having at least two ethenoxy groups is the diethyenyl ester of 3-hydroxyadipic acid.

[0034] In some embodiments, the material having an ester group is an oligomer. Examples of oligomers include the reaction products of polyols with lactones, such as ε-caprolactone. In addition, the incorporation of monomeric

acids and/or alcohols may be used to adjust the molecular weight of the polyester.

[0035] In some embodiments, the material having an ester group is a fatty acid ester. Fatty acid esters include fatty acids with multiple ester groups, such as diesters. Fatty acid esters include fatty acids esterified by reaction with various alcohols. For example, fatty acids may be esterified with methanol or ethanol to form fatty acid methyl esters and fatty acid ethyl esters. Various fatty acid esters are derived from biomass sources for production of biodiesel.

[0036] Suitable fatty acid esters and diesters may be based on the following oils, for example: castor oil, coconut oil (copra oil), corn oil, cottonseed oil, false flax oil, hemp oil, mustard oil, palm oil, peanut oil, radish oil, rapeseed (canola) oil, ramtil oil, rice bran oil, safflower oil, soybean oil, sunflower oil, tung oil, algae oil, copaiba, honge oil, pioneered jatropha oil, jojoba oil, milk bush, petroleum nut oil, dammar oil, linseed oil, poppyseed oil, stillingia oil (also called Chinese vegetable tallow oil), and vernonia oil.

[0037] Diesters of C18 fatty acid dimers may also be used. Examples include Pripol™ 1009 from Uniqema, a distilled and hydrogenated acid dimer which may be further reacted with an alcohol, such as methanol, to form a diester. [0038] The hydroxy compound having a carbamate group includes at least one hydroxy! group and at least one carbamate group. In some embodiments, the hydroxy compound having a carbamate group may have a plurality of hydroxyl groups and/or a plurality of carbamate groups. The hydroxy compound having a carbamate group may be a hydroxyalkyl carbamate, such as for example, hydroxymethyl carbamate, hydroxyethyl carbamate, hydroxypropyl carbamate, hydroxybutyl carbamate, hydroxycyclohexyl carbamate, or hydroxyphenyl carbamate.

[0039] In some embodiments, the hydroxy compound having a carbamate group has the formula (4):

wherein, R ³ is C ₂ -C2 ₀ alkylene; C ₅ -Ci ₂ cycloalkylene; or C ₂ -C _2O alkylene interrupted by one or more oxygen and/or sulfur atoms and/or by one or more substituted or unsubstituted imino groups and/or by one or more cycloalkyl, - (CO)- -0(CO)O-, -(NH)(CO)O-, -0(CO)(NH)-, -0(CO)- or -(CO)O- groups. R ⁴ and R ⁵ are each independently hydrogen; CrCi ₈ alkyl; C ₂ -Ci ₈ alkyl uninterrupted or interrupted by one or more oxygen and/or sulfur atoms and/or by one or more substituted or unsubstituted imino groups; C ₂ -Ci ₈ alkenyl; Ce-Ci ₂ aryl; C ₅ -Ci ₂ cycloalkyl; five- to six-membered heterocycle containing oxygen, nitrogen and/or sulfur atoms; or a group of the formula -[Xj] _k -H, where k is a number from 1 to 50, and Xj for i=1 to k can be selected independently from the group consisting of -CH ₂ -CH ₂ -O-, -CH ₂ -CH ₂ -N(H)-, -CH ₂ -CH ₂ -CH ₂ -N(H)-, -CH ₂ -CH(NH ₂ )- -CH ₂ -CH(NHCHO)-, -CH ₂ -CH(CH ₃ )-O- -CH(CH ₃ )-CH ₂ - 0-, -CH ₂ -C(CHa) ₂ -O-, -C(CHs) ₂ -CH ₂ -O-, -CH ₂ -CH ₂ -CH ₂ -O-, -CH ₂ -CH ₂ - CH ₂ -CH ₂ -O-, -CH ₂ -CHVJn-O-, -CHVJn-CH ₂ -O-, -CH ₂ -CHPh-O-, and - CHPh-CH ₂ -O-, where Ph stands for phenyl and Vin stands for vinyl. [0040] R ⁴ and R ⁵ can also together form a ring. [0041] Where R ⁴ and R ⁵ are hydrogen, the hydroxy compound is known as having a primary carbamate group.

[0042] Preferably R ⁴ and R ⁵ are independently hydrogen, CrCi ₂ alkyl, C ₅ -C ₆ cycloalkyl or a group of the formula -[Xi]κ-H; with particular preference R ⁴ and R ⁵ are independently hydrogen, CrC ₄ alkyl, C ₅ -Cβ cycloalkyl or a group of the formula -[Xi]HH; and very preferably R ⁴ and R ⁵ are hydrogen, C ₁ -C4 alkyl, or a group of the formula -[Xi] _k -H _; In particular, one of the radicals R ⁴ and R ⁵ is hydrogen and the other is CrC ₄ alkyl, or a group of the formula -[Xi] _k -H. [0043] R ³ is preferably C2-C10 alkylene, more preferably C ₂ -C ₆ alkylene, very preferably C ₂ -C ₄ alkylene, in particular C ₂ -C ₃ alkylene, and especially C ₂ alkylene, it being possible for each of the radicals stated to be substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and/or heterocycles.

[0044] k is preferably 1 to 30, more preferably 1 to 20, very preferably 1 to 10, and in particular 1 to 5.

[0045] Preferred Xi are -CH ₂ -CH ₂ -O-, -CH ₂ -CH ₂ -N(H)-, -CH ₂ - CH ₂ -CH ₂ -N(H)-, -CH ₂ -CH(NH ₂ )- -CH ₂ -CH(NHCHO)- -CH ₂ -CH(CH ₃ )-O-

and -CH(CHa)-CH ₂ -O-, more preferably -CH ₂ -CH ₂ -O-, -CH ₂ -CH ₂ -N(H)-, - CH ₂ -CH ₂ -CH ₂ -N(H)- and -CH ₂ -CH(NH ₂ )-, very preferably -CH ₂ -CH ₂ -O-, - CH ₂ -CH ₂ -N(H)-, and -CH ₂ -CH ₂ -CH ₂ -N(H)-.

[0046] Examples of R ⁴ and R ⁵ include hydrogen, methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-heptyl, n- octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, 2- ethylhexyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 2-hydroxyethyl, 2- hydroxypropyl, 1 -hydroxypropyl, 5-hydroxy-3-oxapentyl, 8-hydroxy-3,6-dioxaoctyl or 11-hydroxy-3,6,9-trioxaundecyl. [0047] Examples of R ³ include 1 ,2-ethylene, 1 ,2-propylene, 1 ,1- dimethyl-1 ,2-ethylene, 1 -hydroxymethyl-1 ,2-ethylene, 2-hydroxy-1 ,3-propylene, 1 ,3-propylene, 1 ,4-butylene, 1 ,6-hexylene, 2-methyl-1 ,3-propylene, 2-ethyl-1 ,3- propylene, 2,2-dimethyl-1 ,3-propylene, and 2,2-dimethyl-1 ,4-butylene, preferably 1 ,2-ethylene, 1 ,2-propylene, and 1 ,3-propylene, more preferably 1 ,2-ethylene and 1 ,2-propylene, and very preferably 1 ,2-ethylene.

[0048] In some embodiments, the hydroxy compound having a carbamate group may have a carbamate group having the formula (5):

in which R is H or alkyl, preferably R is H or alkyl of from 1 to about 8 carbon atoms, more preferably R is H or alkyl of from 1 to about 4 carbon atoms, and yet more preferably R is H. When R is H, the carbamate group is referred to as a primary carbamate group.

[0049] Further examples of hydroxy compounds having a carbamate group include hydroxyalkyl carbamate compounds prepared from the ring- opening of cyclic carbonates with ammonia (to form primary carbamate groups) or primary or secondary amines (for secondary or tertiary carbamate groups) such as hydroxymethyl carbamate, hydroxyethyl carbamate, hydroxypropyl carbamate, hydroxybutyl carbamate, hydroxycyclohexyl carbamate, hydroxyphenyl carbamate, beta-hydroxypropyl carbamate, and gamma-hydroxy carbamate; the beta-hydroxy carbamate formed from the reaction of carbon dioxide with 2,3-epoxy-1 -propanol or the epoxy ester of neodecanoate; and

asymmetric hydroxy carbamates as described by Ohrbom et al., U.S. Patent Nos. 6,977,309 and 6,858,674.

[0050] In some embodiments, the hydroxy compound having a carbamate group is formed by reacting an amine or ammonia and a cyclic carbonate, as disclosed by U.S. Pat. Nos. 6,740,706, 6,838,530, and 6,624,279, which are incorporated herein by reference.

[0051] Biocatalysts used in the present compositions and methods originate from living organisms and are capable of catalyzing the above- described transesterification reactions . Biocatalysts may originate from microorganisms or from animals and plants, and include enzymes. Enzymes can include those having hydrolase activity such as lipase activity, esterase activity, protease activity, and amidase activity. For example, enzymes capable of catalyzing transesterification reactions may form an acyl-enzyme intermediate with the material having an ester group. This acyl-enzyme intermediate involves a covalent bond between a serine residue of the enzyme and the material having an ester group with the release of an alcohol byproduct. Such enzymes may include those having a catalytic triad formed of serine, aspartate, and histidine residues.

[0052] Typical examples of enzymes which originate from microorganisms are Lipase P (originates from genus Pseudomonas) from Amano Enzyme Inc., Lipase PS (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase A6 (originates from genus Aspergillus) from Amano Enzyme Inc., Lipase AP6 (originates from genus Aspergillus) from Amano Enzyme Inc., Lipase M-10 (originates from genus Mucoή from Amano Enzyme Inc., Lipase OF (originates from genus Candida) from Meito Sangyo Co., Ltd., Lipase PL (originates from genus Alcaligenes) from Meito Sangyo Co., Ltd., Lipase QLM (originates from genus Alcaligenes) from Meito Sangyo Co., Ltd., Lipase SL (originates from Burkholderia cepacia) from Meito Sangyo Co., Ltd., Lipase TL (originates from Pseudomonas stutzeri) from Meito Sangyo Co., Ltd., Lipase MY (originates from Candida cylindracea) from Meito Sangyo Co., Ltd., Toyozyme LIP (originates from genus Pseudomonas) from TOYOBO Co., Ltd., Lipase Type VII (originates from Candida rugosa) from Sigma-Aldrich, Inc.,

Acylase I (originates from Aspergillus melleus) from Sigma-Aldrich, Inc., Protease Type XXXI (originates from Bacillus licheniformis) from Sigma-Aldrich, Inc., Lipase (originates from Candida antarctica) from Fluka, Lipozyme IM 20 (originates from Humicola lanuginosa) from Novo Nordisk Pharma Ltd., Lipase M (originates from Mucor javanicus) from Amano Enzyme Inc., Lipase MFL from Amano Enzyme Inc., Novozyme 435 (originates from Candida antarctica) from Novo Nordisk Pharma Ltd., Lipozyme RM IM (originates from Rhizomucor miehei) from Novo Nordisk Pharma Ltd., Lipozyme TL IM (originates from Thermomyces lanuginosus) from Novo Nordisk Pharma Ltd., Alcalase (originates from Bacillus licheniformis) from Novo Nordisk Pharma Ltd., Durazym (originates from genus Bacillus) from Novo Nordisk Pharma Ltd., Esperase (originates from genus Bacillus) from Novo Nordisk Pharma Ltd., Savinase (originates from genus Bacillus) from Novo Nordisk Pharma Ltd., Bioplase Cone, (originates from Bacillus subtilis) from Nagase Biochemicals Co., Lipase AY (originates from Candida rugosa) from Amano Enzyme Inc., Lilipase A-10 (originates from Rhizopus japonicus) from Nagase Biochemicals Co., Lipase 2G (originates from genus Pseudomonas) from Nagase Biochemicals Co., Bioplase AL-15FG (originates from Bacillus subtilis) from Nagase Biochemicals Co., Lipase PS-C "Amano" I (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase PS-C "Amano" Il (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase PS-D "Amano" I (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase AK "Amano" 20 (originates from Pseudomonas fluorescens) from Amano Enzyme Inc., CHIRAZYME L-2 (originates from Candida antarctica) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-3 (originates from Candida rugosa) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-3p (originates from Candida rugosa) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-6 (originates from genus Pseudomonas) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-8 (originates from Thermomyces lanuginos) from F. Hoffmann-La Roche Ltd., CHIRAZYME L- 9 (originates from genus Rhizomucor) from F. Hoffmann-La Roche Ltd., and CHIRAZYME L-10 (originates from genus Alcaligenes) from F. Hoffmann-La Roche Ltd.

[0053] Typical examples of enzymes that originate from animals are Pancreatin (originates from swine) from Amano Enzyme Inc., Porcine Pancreas Lipase (originates from swine) from Sigma-Aldrich, Inc., CHIRAZYME L-7 (originates from swine) from F. Hoffmann-La Roche Ltd. A typical example of an enzyme originating from plants includes Papain (originates from papaya) from Sigma-Aldrich, Inc.

[0054] Of the above-described enzymes, preferred are Lipase P (originates from genus Pseudomonas) from Amano Enzyme Inc., Lipase PS (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase PS-C "Amano" I (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase PS-C "Amano" Il (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase PS-D "Amano" I (originates from Pseudomonas cepacia) from Amano Enzyme Inc., Lipase AK "Amano" 20 (originates from Pseudomonas fluorescens) from Amano Enzyme Inc., Lipase AY (originates from Candida rugosa) from Amano Enzyme Inc., Lipase OF (originates from genus Candida) from Meito Sangyo Co., Ltd., Lipase PL (originates from genus Alcaligenes) from Meito Sangyo Co., Ltd., Lipase QLM (originates from genus Alcaligenes) from Meito Sangyo Co., Ltd., Lipase SL (originates from Burkholderia cepacia) from Meito Sangyo Co., Ltd., Lipase TL (originates from Pseudomonas stutzeri) from Meito Sangyo Co., Ltd., Lipase MY (originates from Candida cylindracea) from Meito Sangyo Co. Ltd., Novozym435 (originates from Candida antarctica) from Novo Nordisk Pharma Ltd., CHIRAZYME L-2 (originates from Candida antarctica) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-6 (originates from genus Pseudomonas) from F. Hoffmann-La Roche Ltd., CHIRAZYME L-9 (originates from genus Rhizomucoή from F. Hoffmann-La Roche Ltd., and CHIRAZYME L-10 (originates from genus Alcaligenes) from F. Hoffmann-La Roche Ltd.

[0055] The reaction between the hydroxy carbamate compound and the material having an ester group can be catalyzed by lipase. Crude lipases AK, PS-30, CES from Pseudomonas sp., lipase AP from Aspergillus niger sp., lipase MAP from Mucor sp., lipase G from Penicillium cyclopium sp., lipase GC

from Geotricum candidum sp., lipase FAP from Rhizopus javanicus, are available from Amano International Enzyme Company, Troy, Virginia.

[0056] Enzymes which can be used to catalyze the adduction reaction are selected for example from hydrolases, esterases (E.C. 3.1.-.-), lipases (E. C. 3.1.1.3), glycosylases (E.C. 3.2.-.-) and proteases (E.C. 3.4.-.-) in free form or in a form in which they are chemically or physically immobilized on a carrier or solid support, preferably lipases, esterases or proteases. Particular preference is given to Novozyme 435 (lipase from Candida antarctica B) or lipase from Aspergillus sp., Aspergillus niger sp., Mucor sp., Penicillium cyclopium sp., Geotricum candidum sp., Rhizopus javanicus, Burkholderia sp., Candida sp., Pseudomonas sp., or porcine pancreas, very particular preference to lipase from Candida antarctica B or from Burkholderia sp.

[0057] Not only crude or purified isolated enzymes, as described above, but also living cells capable of catalyzing the above-described transesterification reaction, or the processed product thereof, can be used as the biocatalyst. As such, living cells, microorganisms, animal cells, and plant cells can be used. For example, a culture solution obtained by culturing a microorganism can be used as it is, or cells obtained from the culture by harvesting processes such as centrifugation can be used, or processed product of the cells can be used. In cases where synthesized enzymes are secreted extracellularly, culture media after cell removal operations, such as centrifugation, can be used. However, it can be more effective to subject such culture media to a concentration process and/or purification process, such as ammonium sulfate precipitation. Processed products of cells includes, for example, cells treated with acetone or toluene, etc., freeze-dhed cells, disrupted cells, cell-free extract from disrupting cells, and a crude enzyme solution obtained by extracting the enzyme from any one of these products.

[0058] Typical examples of the microorganisms used as biocatalysts include microorganisms of: genus Pseudomonas, genus Agrobacterium, genus Bacillus, genus Microbacterium, genus Aspergillus, genus Mucor, genus Rhizomucor, genus Mortierella, genus Nocardia, genus Stenotrophomonas, genus Brevundimonas, genus Rhodococcus, genus Aeromonas, genus Candida,

genus Pichia, genus Debaryomyces, genus Alcaligenes, genus Humicola, genus Thermomyces, and genus Rhizopus.

[0059] More specifically, microorganisms of genus Pseudomonas include, for example, Pseudomonas cepacia, Pseudomonas aeruginosa (IAM 1220), Pseudomonas aeruginosa (IAM 1267), Pseudomonas aeruginosa (IAM 1275), Pseudomonas aeruginosa (IAM 1514), Pseudomonas fluorescens (IAM 1008) and Pseudomonas ovalis (IAM 1002); microorganisms of genus Agrobacterium include, for example, Agrobacterium rhizogenes (IFO 13257); microorganisms of genus Bacillus include, for example, Bacillus subtilis and Bacillus licheniformis; microorganisms of genus Microbacterium include, for example, Microbacterium barker! (JCM 1343); microorganisms of genus Aspergillus include, for example, Aspergillus niger, Aspergillus melleus and Aspergillus oryzae; microorganisms of genus Mucor include, for example, Mucor miehei and Mucor javanicus (IFO 4572); microorganisms of genus Mortierella include, for example, Mortierella isabellina (IFO 7824); microorganisms of genus Nocardia include, for example, Nocardia rubra (IFM 18); microorganisms of genus Stenotrophomonas include, for example, Stenotrophomonas maltophilia (IFO 12020) and Stenotrophomonas maltophilia (IFO 12690); microorganisms of genus Brevundimonas include, for example, Brevundimonas diminuta (IFO 14213); microorganisms of genus Rhodococcus include, for example, Rhodococcus equi {\FO 3730); microorganisms of genus Aeromonas include, for example, Aeromonas hydrophila (IFO 3820); microorganisms of genus Candida include, for example, Candida rugosa, Candida antarctica and Candida tropicalis (IAM 4965); microorganisms of genus Pichia include, for example, Pichia anomala (IFO 146); microorganisms of genus Debaryomyces include, for example, Debaryomyces hansenii (IFO 34); microorganisms of genus Humicola include, for example, Humicola lanuginose; microorganisms of genus Thermomyces include, for example, Thermomyces lanuginos; and microorganisms of genus Rhizopus include, for example, Rhizopus japonicus. Among the above-described microorganisms, preferred are Pseudomonas aeruginosa (IAM 1267), Pseudomonas aeruginosa (IAM 1220), Pseudomonas

aeruginosa (IAM 1514), Brevundimonas diminuta (IFO 14213), Nocardia rubra (IFM 18) and Rhodococcus equi (\FO 3730).

[0060] These microorganisms are well known and can be obtained easily from, for example, Institute for Fermentation, Osaka, Japan (IFO), Institute of Applied Microbiology, the University of Tokyo (IAM), Japan Collection of

Microorganisms, Institute of Physical and Chemical Research (JCM), and

Research Center for Pathogenic Fungi and Microbial Toxioses, Chiba University.

[0061] The variants of the above-described organisms or microorganisms obtained by isolating the intended enzyme genes, introducing the same into a host vector system in the usual way, and transforming a host with the vector, can also be used.

[0062] Microorganisms that catalyze the reaction of the present invention can be obtained by, for example, the following process. First, suitable nutrient medium is selected and microorganisms are cultured in the medium. After completion of the cultivation, cells and supernatant are harvested by a process such as centrifugation. The cells or supernatant is added to a reaction medium that contains a material having an ester group and a hydroxy compound having a carbamate and the solution is shaken or mixed for a reaction period at a suitable temperature, for example 30 ⁰ C. After completion of the reaction, the presence or absence of the products or reactants may be determined by GC (gas chromatography), thereby determining the presence or absence of biocatalyst activity.

[0063] In the present compositions and methods, when using biocatalysts in the reaction, the form in which the biocatalysts are used is not particularly limited, as long as they have catalytic activity. For example, the biocatalysts may be used after immobilizing them on appropriate carriers by a conventional process. Immobilization can be achieved by encompassing the biocatalyst in, for example, cross-linked acrylamide gel, polysaccharides, or by immobilizing the biocatalysts physically or chemically on solid carriers such as ion-exchange resin, magnetic beads, diatomaceous earth, or ceramic. The biocatalyst may be affixed to a solid support comprising a surface. In some cases, the solid support is in the shape of beads that can be used either in a

batch process or used within a column through which the reactants are passed. The catalytic activities of biocatalysts may be increased when used in the immobilized form. In addition, the use of biocatalysts in the immobilized state facilitates separation and recovery after completion of the reaction, thereby the biocatalysts can be recovered and recycled and the isolation and separation of reaction products in an easier and quicker fashion.

[0064] The water content of the biocatalyst can be reduced by freeze- drying or vacuum drying treatment or treatment using organic solvents such as acetone, methanol and ethanol. Removal of water may facilitate reactions that are carried out in the presence of one or more organic solvents.

[0065] In the present invention, usually one kind of biocatalyst selected from the above-described ones is used. However, it is also possible to use two or more kinds of biocatalysts of similar activity in the mixed form.

[0066] In the present invention, any medium for culturing the chosen microorganism can be used as long as the microorganism can grow therein. As a carbon source, saccharides such as glucose, sucrose, and maltose; organic acids such as acetic acid, citric acid and fumaric acid and the salts thereof; and alcohols such as ethanol and glycerol may be used. As a nitrogen source, not only general types of natural nitrogen sources such as peptone, meat extract, yeast extract and amino acids, but also various kinds of inorganic ammonium salts and organic acid ammonium salts may be used. Inorganic salts, trace metal salts, vitamins, etc. are appropriately added if desired or necessary. In some cases, microorganisms can be induced to express more of the desired enzyme activity, such as increased expression of lipase, by culturing the microorganisms using medium containing oils such as olive oil, soy bean oil, etc. or medium containing compounds having an ester bond or an amide bond.

[0067] The microorganisms can be cultured by conventional process. For example, the cultivation may be carried out under aerobic conditions for 6 to 96 hours, at pH 4 to 10, and at temperature of 15°C to 40 ⁰ C. [0068] The biocatalyst can perform a transesterification reaction, as illustrated by the reaction formula (6):

_R 1 _{+ H 0} . ,R ²

(6) where R ¹ and R ² are defined as per formula (1 ) and R ³ , R ⁴ , and R ⁵ are defined as per formula (4). [0069] In some embodiments, R ² in reaction formula (6) is an ethylene group, which can drive the transesterification reaction forward since the vinyl alcohol product (HO-R ² , where R ² is ethylene) can tautomerize to acetaldehyde and is effectively removed from the reaction equilibrium.

[0070] The biocatalyst reaction is preferably performed in aqueous mixture or in an organic solvent or solvent mixture that preserves a small monolayer of water surrounding the enzyme. Aromatic hydrocarbon solvents such as toluene, xylene, and mixtures of aromatic hydrocarbons with range of fractional distillation of 90°C to 220 ⁰ C obtained by fractionally distilling coal tar- based light oil and petroleum-based light oil can be used, such as Solvesso 100 and Aromatic 100 (from Exxon. Mobil Corp.), which have boiling point solvents with range of fractional distillation of 16O ⁰ C to 18O ⁰ C, and Solvesso 150 and Aromatic 150 (from Exxon Mobil Corp.), which have boiling point solvents with range of fractional distillation of 180 ⁰ C to 220 ⁰ C. For example, the reaction may be performed in a reaction medium comprising an aqueous solution, an organic solution, an emulsion having an aqueous continuous phase and an organic discontinuous phase, or an emulsion having an organic continuous phase and an aqueous discontinuous phase. In one embodiment, the reaction is performed in a reaction medium comprising toluene and tetrahydrofuran.

[0071] The reaction mixture containing the lipase, the hydroxy compound containing a carbamate group and the material having an ester group may be heated to a reaction temperature of from 30 ⁰ C up to about 120 ⁰ C, preferably from about 40 ⁰ C up to about 60 ⁰ C. The reaction temperature depends at least in part on the thermal stability of the hydroxy carbamate being reacted; beta hydroxy carbamates can undergo unwanted de-amination to reform cyclic carbonates, a side-reaction that should be avoided. In using

compounds susceptible to this side-reaction, it may be helpful to keep the reaction temperature under 60 ⁰ C. When the carbamate and hydroxyl groups of the hydroxy compound having a carbamate group are separated by three or more carbon atoms, the reactant compound is usually stable enough to use reaction temperatures up to about 12O ⁰ C. The reaction mixture is held at the reaction temperature until the reaction is complete, typically from about four to about forty hours. The alcohol byproduct may be left in the reaction mixture, may be drawn off by distillation or vacuum distillation during the reaction in order to help drive the reaction to completion, or may be drawn off after the reaction. [0072] Alternatively, a hydroxy compound having a carbamate group is added to a polymeric, oligomeric or fatty acid material having an ester of a low boiling point alcohol (usually a methyl to propyl ester) via enzymatic transcarbamation using methods similar to those used to make carbamate functional (meth)acrylic monomers, as taught in U.S. Patent 7,164,037. In this approach, the material to which the hydroxy carbamate compound is adducted contains one or more esters of a low boiling point alcohol, usually a methyl, ethyl or propyl ester. The material having the ester group(s) is heated in the presence of a hydroxy compound having a carbamate group, as described above. To help with the removal of the alcohol, the reaction may be carried out under vacuum. [0073] The enzyme content of the reaction medium generally lies in a range from about 0.1% to about 10% by weight, based on the sum of the reactants employed. The reaction time can depend on the temperature, amounts and activity of the biocatalyst used, and on the desired conversion to form the carbamate functional material, and also on the hydroxy compound having a carbamate group. The reaction time is preferably adapted so that the conversion of all hydroxyl groups originally present in the compound with a carbamate group is at least 70%, preferably at least 80%, more preferably at least 90%, and very preferably at least 95%. For this, a time of from 1 to 48 hours and preferably from 1 to 12 hours is generally sufficient. Mild vacuum may be applied during the reaction to remove any low boiling point alcohol byproduct. The reaction temperature is usually between 30 ⁰ C to 12O ⁰ C, and is selected based on the stability of the hydroxy carbamate as described above.

[0074] The two substrates, the material having an ester group and the hydroxy compound having a carbamate group, are alternatively in solution, in suspension as solids, in an aqueous solution, an organic solution, an emulsion having an aqueous continuous phase and an organic discontinuous phase, or an emulsion having an organic continuous phase and an aqueous discontinuous phase. The initial concentration of the reactants is preferably in the range from about 0.1 to 20 mol/L, in particular from 0.15 to 10 mol/L, or from 0.2 to 5 mol/L.

[0075] The reaction can take place continuously, in a tube reactor or in a cascade of stirred reactors, for example, or batchwise. The reaction can be carried out in any reactor that is suitable for such processes as described. Reactors of this kind are known to the skilled worker. The reaction takes place preferably in a stirred tank reactor or in a fixed bed reactor. The reaction mixture can be mixed by a variety of methods. There is no need for special stirring equipment. The reaction medium can be single phase or have a plurality of phases and the reactants are dissolved, suspended or emulsified therein, introduced into the reaction vessel together where appropriate with the molecular sieve, and admixed with the biocatalyst preparation at the beginning of the reaction and also, where appropriate, one or more times during the course of the reaction. During the reaction, the temperature is set at the desired level and can be raised or lowered if desired during the course of the reaction.

[0076] If the reaction is carried out in a fixed bed reactor, the reactor is preferably packed with immobilized enzymes, with the reaction mixture being pumped through a column packed with the enzyme. It is also possible to carry out the reaction in a fluidized bed, with the enzyme being used in immobilized form on a carrier. The reaction mixture can be pumped continuously through the column, in which case the residence time and hence the desired conversion can be controlled via the flow rate. Another possibility is to pump the reaction mixture through a column in circulation, in which case it is possible at the same time to remove the water of reaction and/or liberated alcohol byproduct by distillation, under reduced pressure where appropriate.

[0077] The removal of the water of reaction or of alcohols which are liberated from the transesterification reaction takes place continuously or

gradually in a manner known per se, for example by vacuum, azeotropic removal, absorption, pervaporation, and diffusion via membranes. Means suitable for this purpose include preferably molecular sieves (pore size in the region of about 3 to 10 Angstroms, for example), separation by distillation, or separation with the aid of suitable semipermeable membranes.

[0078] The reaction products prepared by the present methods are generally polymeric, oligomeric, or fatty acid materials modified by transesterifying pendant and/or terminal ester groups of the material to include carbamate functionality. In many cases, not all the pendant and/or terminal ester groups on the material will be transesterified by the hydroxy compound having a carbamate group. In other cases, all or substantially all of the pendant and/or terminal ester groups will be modified. The degree of modification can depend upon the selected reactants, biocatalyst, and other reaction conditions (e.g., time, temperature, pH, removal of alcohol byproduct). Also, in cases where the material having an ester group comprises multiple blocks (e.g., a copolymer or block copolymer), the different blocks may each contain pendant ester groups that differ in some way or one or more blocks may not have any ester groups. The differences in the blocks may be due to the stereochemistry of the repeat units, the length of the spacer between a pendant or terminal ester group and the main chain, or the structure of links between repeat units within each block. Differences in the blocks may be used to create differential reactivity of the pendant or terminal ester groups in the blocks. Thus, the pendant ester groups in one block may react to a greater extent than the pendant ester groups within another block within the material. [0079] Another advantage of the present methods is that materials may be chemically modified to include carbamate groups without altering other side chains groups or sensitive main chain groups. More specifically, by performing enzyme-catalyzed transesterification reactions, hydroxy compounds having a carbamate are linked to pendant or terminal ester groups of the material under relatively mild conditions; e.g., using moderate temperatures, pH, solvents, etc. As such, chemically sensitive groups remain relatively unchanged during the transesterification. Examples of where this can be important include

materials having that have a main chain with silicone, phosphate, carbonate, or other chemically labile groups. Conventional methods to add carbamate functionality to the material may cleave such bonds or result in undesired modifications, where the present enzymatic methods are sufficiently mild to retain the structure of these groups. In some cases, such chemically sensitive groups may be present on the hydroxy compound having a carbamate that is reacted with the material having an ester group. In addition, enzymes may be selective for particular substrates or portions of a substrate, and preferentially incorporate carbamate functionality at these positions. [0080] The carbamate functional material made according to the present methods can be used in a coating composition. The carbamate functional material may be used in a pigmented and/or clearcoat coating composition and may be used to form a cured coating on a substrate. Such coating compositions may be used to coat automotive and industrial substrates, including metal, plastic, or composite substrates. The industrial and automotive coatings may be primers or topcoats, including one-layer topcoats and basecoat/clearcoat composite coatings.

[0081] In some embodiments, the coating compositions are thermosetting. Thermosetting coating compositions preferably include a curing agent (i.e., crosslinker) that is reactive with the carbamate functionality of the polymer or compound. The curing agent typically has two or more reactive functional groups. The reactive functional groups may include groups reactive with carbamate groups.

[0082] Useful curing agents include materials having active methylol or methylalkoxy groups, such as aminoplast crosslinking agents or phenol/formaldehyde adducts. Examples of preferred curing agents include, without limitation, melamine formaldehyde resins (including monomeric or polymeric melamine resin and partially or fully alkylated melamine resin) and urea resins (e.g., methylol ureas such as urea formaldehyde resin, alkoxy ureas such as butylated urea formaldehyde resin). Curing agents may include combinations of various curing agents. Aminoplast resins such as melamine formaldehyde resins or urea formaldehyde resins are especially preferred.

Combinations of tris(alkoxy carbonylamino) triazine with a melamine formaldehyde resin and/or a blocked isocyanate curing agent are likewise suitable.

[0083] In some embodiments, the present disclosure provides a method of coating a substrate. A coating composition, including a carbamate functional material made according to the present methods and a crosslinking agent, is applied to the substrate. The applied coating composition is then cured by reacting the carbamate-functional material and the crosslinker.

[0084] The coating composition may be prepared by including the solvents and/or reaction medium in which the reaction between the material having an ester group and the hydroxy compound having a carbamate group is carried out, or the reaction solvents may be removed by distillation and replaced with other solvents. In general, the solvent used in the coating composition can be any organic solvent and/or water. In one preferred embodiment, the solvent includes a polar organic solvent. More preferably, the solvent is selected from polar aliphatic solvents or polar aromatic solvents. Still more preferably, the solvent is a ketone, ester, acetate, aprotic amide, aprotic sulfoxide, aprotic amine, or a combination of any of these. Examples of useful solvents include, without limitation, methyl ethyl ketone, methyl isobutyl ketone, m-amyl acetate, ethylene glycol butyl ether-acetate, propylene glycol monomethyl ether acetate, xylene, N-methylpyrrolidone, blends of aromatic hydrocarbons, and mixtures of these. In another preferred embodiment, the solvent is water or a mixture of water with small amounts of co-solvents.

[0085] In some embodiments, the solvent can be a reactive diluent, and can be the product formed according to the present methods. For example, the dicarbamate of a dimerized fatty acid may act as both the solvent and resin in a coating, as disclosed by US 6,541 ,594, which is incorporated herein by reference. In some embodiments, the coating composition may be solvent less and applied as a powder, as is known in the art. [0086] Coating compositions can be coated on the article by any of a number of techniques well-known in the art. These include, for example, spray

coating, dip coating, roll coating, curtain coating, and the like. For automotive body panels, spray coating is often performed.

[0087] The coating compositions of the invention include topcoat compositions, including one-layer pigmented topcoat compositions as well as clearcoat and basecoat two-layer topcoat compositions. When the resins of the invention are utilized in aqueous compositions, they may include monomers with groups that can be salted, i.e., acid groups or amine groups.

[0088] Additional agents, for example surfactants, fillers, stabilizers, wetting agents, dispersing agents, adhesion promoters, UV absorbers, hindered amine light stabilizers, pigments, etc. may be incorporated into the coating composition. While such additives are well-known in the prior art, the amount used must be controlled to avoid adversely affecting the coating characteristics.

[0089] When the coating composition of the invention is used as a high-gloss pigmented paint coating, the pigment may be any organic or inorganic compounds or colored materials, fillers, metallic or other inorganic flake materials such as mica or aluminum flake, and other materials of kind that the art normally includes in such coatings. Pigments and other insoluble particulate compounds such as fillers are usually used in the composition in an amount of 1% to 100%, based on the total solid weight of binder components (i.e., a pigment-to-binder ratio of 0.1 to 1.0). Preferably, the coating composition of the invention is a clearcoat coating composition, which has no pigments.

[0090] The coating compositions described herein are preferably subjected to conditions so as to cure the coating layers. Although various methods of curing may be used, heat-curing is preferred. Generally, heat curing is effected by exposing the coated article to elevated temperatures provided primarily by radiative heat sources. Curing temperatures will vary depending on the particular blocking groups used in the cross-linking agents, however they generally range between 90 ⁰ C and 180 ⁰ C. The first compounds according to the present invention are preferably reactive even at relatively low cure temperatures. Thus, in a preferred embodiment, the cure temperature is preferably between 115°C and 150 ⁰ C, and more preferably at temperatures between 115 ⁰ C and 140 ⁰ C for a blocked acid catalyzed system. For an

unblocked acid catalyzed system, the cure temperature is preferably between 80 ⁰ C and 100 ⁰ C. The curing time will vary depending on the particular components used, and physical parameters such as the thickness of the layers, however, typical curing times range from 15 to 60 minutes, and preferably 15-25 minutes for blocked acid catalyzed systems and 10-20 minutes for unblocked acid catalyzed systems.

[0091] The invention is further described in the following examples. The examples are merely illustrative and do not in any way limit the scope of the invention as described and claimed. All parts are parts by weight unless otherwise noted.

EXAMPLES [0092] Example 1 [0093] Part One: [0094] A solution of 20 parts of xylene is heated to 140 ⁰ C under an inert atmosphere. Then a mixture of 26 parts of vinyl methacrylate, 5 parts of styrene, 25 parts of butyl acrylate, 9 parts of cyclohexane methacrylate, 5.2 parts of t-butyl peroxy-2-ethylhexanoate and 7 parts of amyl acetate are added at a constant rate over four hours. Then 2.8 parts of xylene are added. The reaction mixture is held at 140 ⁰ C for two hours. The final resin will have a vinyl equivalent weight of 430 g/equ (solution) and a NV of about 67.6%. [0095] Part Two:

[0096] To 100 parts of the resin from example one part one is added

50 parts of hydroxy ethyl carbamate and 1 part of PS-30 Pseudomonas. The reaction mixture is then heated under an inert atmosphere to 50 ⁰ C and held until the reaction is complete (as determined by GC analysis of loss of hydroxyethyl carbamate). Then the solvent and excess hydroxyethyl carbamate are removed under mild vacuum distillation, where the distillation temperature is kept below

120 ⁰ C. Then 30 parts of amyl acetate is added. The final resin will have a NV content of about 62% and a carbamate equivalent weight on solution of 524 g/equ.

[0097] Example 2

[0098] Part One:

[0099] A solution of 120 parts of xylene, 158 parts of the homopolymer of isophorone diisocyanate, and 0.2 parts of dibutyl tin dilaurate is heated under an inert atmosphere to 60 ⁰ C. Then 74 parts of the ethenyl ester of 3- hydroxypropanoic acid is slowly added. The reaction mixture is allowed to exotherm to 8O ⁰ C during the addition. The reaction is held at 8O ⁰ C and followed by infrared spectroscopy until the reaction is complete. Then 5 parts of butanol are added. The resin will have a NV content of about 65% and a vinyl equivalent weight of 562 g/equ on solution. [0100] Part Two:

[0101] To 100 parts of the resin from part one of this example, is added 40 parts of hydroxyethyl carbamate and 1 part of PS-30 Pseudomonas. The reaction mixture is then heated under an inert atmosphere to 50 ⁰ C and held until the reaction is complete (as determined by GC analysis of loss of hydroxy ethyl carbamate). Then the solvent and excess hydroxyethyl carbamate is removed under mild vacuum distillation where the distillation temperature is kept below 120 ⁰ C. The final solid material has a carbamate equivalent weight of 470 g/equ. It can be used as a powder, or reduced in solvent (such as amyl acetate).

[0102] Example 3 [0103] Part One:

[0104] A solution of 120 parts of xylene and 158 parts of the homopolymer of isophorone diisocyanate and 0.2 parts of dibutyl tin dilaurate are heated under an inert atmosphere to 60 ⁰ C. Then 67 parts of methyl-3- hydroxypropanoate is slowly added. The rate of addition is monitored in order to keep the reaction temperature below 70 ⁰ C. Once all of the 2-hydroxyethyl acrylate has been added, the reaction mixture is kept at 70 ⁰ C until the reaction is complete (as determined by infrared spectroscopy). Then 5 parts of butanol are added. The resin will have a NV of 64% and a methyl ester equivalent weight of

543 g/equ on solution. [0105] Part Two:

[0106] 100 parts of the resin from example three part one, 44 parts of hydroxypropyl carbamate and 2 parts of Novozym 435 (company Novozymes) is

heated to 7O ⁰ C under an inert atmosphere in a reactor equipped with a trap. The reaction is kept at 70 ⁰ C and monitored by removal of water and disappearance of hydroxypropyl carbamate. Once the reaction is complete, the excess hydroxypropyl carbamate and solvent is removed under mild vacuum distillation where the distillation temperature is kept below 120 ⁰ C. The final solid material has a carbamate equivalent weight of 466 g/equ. It can be used as a powder, or reduced in solvent (such as amyl acetate).

[0107] The invention has been described in detail with reference to preferred embodiments thereof. It should be understood, however, that variations and modifications can be made within the spirit and scope of the invention and of the following claims.