Patent GB-872139-A (GB)
Title: Improvements relating to interpolymers and coating compositions containing them
IPC: C08F8/00
Filed: 1959-08-11
Abstract: Interpolymers suitable for use in coating compositions are prepared by a process which comprises heating at 125 DEG -200 DEG C. a mixture of 30%-80% (molar) styrene, 15%-65% ethyl acrylate and 5%-25% maleic anhydride in the presence of 25%-400% (by weight of the monomers) of an aromatic hydrocarbon solvent until substantially the whole mixture has polymerized and then converting the maleic anhydride in the copolymer into a half ester by esterification with at least one primary or secondary monohydric alcohol or phenol which is free from non-benzenoid unsaturation, contains only carbon, hydrogen and oxygen, has no functional groups other than hydroxyl, and contains up to 18 carbon atoms.  Suitable polymerization catalysts are 0,1 to 2 wt. per cent of di-t-butyl peroxide; benzaldehyde peroxide; 2, 2-bis (t-butylperoxy) butane; t-butyl peracetate; diazoaminobenzene; and cumene hydroperoxide.  Activators, inhibitors, surfactive agents and chain transfer agents may also be present.  Aromatic hydrocarbon solvents specified are benzene, toluene, xylene and several proprietary petroleum distillate fractions.  Esterifying alcohols and phenols specified are the saturated aliphatic alcohols from methyl to stearyl; cycloaliphatic alcohols, e.g. cyclohexyl, methylcyclohexyl and cyclopentyl; and phenol and substituted phenols, e.g. t-butyl phenol, octyl phenol and phenyl-phenol.  Polymer compositions Coating compositions comprise as the essential film-forming material 30-95% wt. of one of the above interpolymers and 70-5% wt. of at least one of urea-formaldehyde-alcohol condensates; melamine-formaldehyde-alcohol condensates; epoxide resins; and epoxidized vegetable oils.  The mixture is dissolved in a volatile organic solvent.  The compositions may contain pigments e.g. metal oxides, hydroxides, chromates, silicates, sulphides, sulphates, and carbonates; carbon blacks; organic dyestuffs and lakes thereof; and metal flakes such as aluminium.  Solvents and diluents mentioned are aromatic and aliphatic hydrocarbons, alcohols, ketones and esters. Mixtures of aromatic hydrocarbons and aliphatic alcohols, e.g. xylene and butanol, are preferred. The epoxidized vegetable oils which may be used may be obtained by epoxidizing the natural or synthetic C8-22 vegetable oil acid esters of polyhydric alcohols, e.g. glycerol or sorbitol. Natural oils mentioned are soya, linseed, dehydrated castor, perilla and cottonseed oils.  The epoxide resins are epoxyhydroxypolyethers and may be obtained by condensing a polyhydric phenol, e.g. diphenylol propane, with an epihalohydrin or a polyepoxy compound.  The formaldehyde resins may be obtained by reacting urea (or melamine) and formaldehyde, or a reaction product thereof, e.g. dimethylol urea (or tetra-, penta-, or hexa-methylol melamine) with methanol, ethanol, propanol or butanol.  Preferably an excess of the alcohol is used.  In examples the pigments used are titanium dioxide and barytes.  In some examples (2 to 5) cetyl dimethyl amine is incorporated as a baking accelerator.  The compositions may be used as enamels for coating refrigerators or washer or drier cabinets. Coating applications  In an Example (1) an enamel containing 80 parts of styrene/ethyl acrylate/2-ethylhexyl maleate interpolymer, 10 parts epoxidized soya oil and 10 parts epoxide resin with butanol, isopropanol and aromatic hydrocarbons as solvents and titanium oxide pigment is diluted to spraying consistency with toluene containing octadecyltrimethylammonium acid phthalate as baking accelerator and is sprayed on to phosphated steel refrigerator cabinet panels to yield 1,5 mil coatings and the panels are baked at 300 DEG F. for 30 minutes.  In Example 6 clear coatings are baked on to polished chrome plate, aluminium and brass.  Specifications 483,399 and 686,234 are referred to.ALSO:Interpolymers suitable for use in coating compositions are prepared by a process which comprises heating at 125-200 DEG C. a mixture of 30-80% (molar) styrene, 15-65% ethyl acrylate and 5-25% maleic anhydride in the presence of 25-400% (by weight of the monomers) of an aromatic hydrocarbon solvent until substantially the whole mixture has polymerized and then converting the maleic anhydride in the copolymer into a half ester by esterification with at least one primary or secondary monohydric alcohol or phenol which is free from non-benzenoid unsaturation, contains only carbon, hydrogen and oxygen, has no functional groups other than hydroxyl, and contains up to 18 carbon atoms.  Suitable polymerization catalysts are 0.1 to 2% wt. of di-t-butyl peroxide; benzaldehyde peroxide; 2,2-bis(t-butylperoxy) butane; t-butyl peracetate; diazoaminobenzene; and cumene hydroperoxide. Activators, inhibitors, surfactive agents and chain transfer agents may also be present.  Aromatic hydrocarbon solvents specified are benzene, toluene, xylene and several proprietary petroleum distillate fractions.  Esterifying alcohols and phenols specified are the saturated aliphatic alcohols from methyl to stearyl; cycloaliphatic alcohols, e.g. cyclohexyl, methylcyclohexyl and cyclopentyl; and phenol and substituted phenols, e.g. t-butyl phenol, octyl phenol and phenyl-phenol.  Polymer compositions  Coating compositions comprise as the essential film-forming material 30-95% wt. of one of the above interpolymers and 70-5% wt. of at least one of urea-formaldehydealcohol condensates; melamine-formaldehydealcohol condensates; epoxide resins; and epoxidised vegetable oils.  The mixture is dissolved in a volatile organic solvent.  The compositions may contain pigmenst, e.g. metal oxides, hydroxides, chromates, silicates, sulphides, sulphates, and carbonates; carbon blacks; organic dyestuffs and lakes thereof; and metal flakes such as aluminium.  Solvents and diluents mentioned are aromatic and aliphatic hydrocarbons, alcohols, ketones and esters.  Mixtures of aromatic hydrocarbons and aliphatic alcohols, e.g. xylene and butanol, are preferred. The epoxidized vegetable oils which may be used may be obtained by epoxidising the natural or synthetic C8-C22 vegetable oil acid esters of polyhydric alcohols, e.g. glycerol or sorbitol.  Natural oils mentioned are soya, linseed, dehydrated castor, perilla and cotton-seed oils.  The epoxide resins are epoxyhydroxy polyethers and may be obtained by condensing a polyhydric phenol, e.g. diphenylol propane, with an epihalohydrin or a polyepoxy compound.  The formaldehyde resins may be obtained by reacting urea (or melamine) and formaldehyde, or a reaction product thereof, e.g. dimethylol urea (or tetra-, penta-, or hexa-methylol melamine) with methanol, ethanol, propenol or butanol.  Preferably an excess of the alcohol is used.  In examples the pigments used are titanium dioxide and barytes.  In some Examples (2 to 5) cetyl dimethyl amine is incorporated as a baking accelerator.  The compositions may be used as enamels for coating refrigerators or washer or drier cabinets.  Coating applications  In an Example (1) an enamel containing 80 parts of styrene/ethyl acrylate/2-ethylhexyl maleate interpolymer, 10 parts expoxidised soya oil and 10 parts epoxide resin with butanol, isopropanol and aromatic hydrocarbons as solvents and titanium oxide pigment is diluted to spraying consistency with toluene containing octadecyltrimethylammonium acid phthalate as baking accelerator and is sprayed on to phosphated steel refrigerator cabinet panels to yield 1.5 mil coatings and the panels are baked at 300 DEG F. for 30 minutes.  In Example 6 clear coatings are baked on to polished chrome plate, aluminium and brass. Specifications 483,399 and 686,234 are referred to.