Patent GB-638516-A (GB)
Title: Polymerisable esters and polymers thereof
Filed: 1947-06-06
Abstract: An ester containing a radical R having an olefinic linkage therein, and a radical R1 containing an epoxide group, these radicals being separated by a carboxyl ester group as in the formula <FORM:0638516/IV (a)/1> is polymerized.  Preferably R is <FORM:0638516/IV (a)/2> , wherein R11, R111 are a divalent and monovalent hydrocarbon radical respectively.  The compounds include mixed esters of polycarboxylic acids wherein the hydrogen of one carboxyl group is replaced by the radical of a monohydric alcohol containing a 1,2-epoxide group, such as glycidol, and of another carboxyl group is replaced by the radical of a monohydric alcohol of 2-18 carbon atoms containing an olefinic linkage.  Any further carboxyl groups may be free or esterified with a saturated hydrocarbon radical.  The esters may be formed by first esterifying the acid with the olefinic alcohol to give a monoester, a metal salt of which is reacted with a halogenated epoxide.  Preferably, acids which form anhydrides are used and are reacted as such, e.g. maleic, phthalic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, mono-and poly-chlorphthalic, and mono- and dichlormaleic. Other acids which may be treated include oxalic, malonic, fumaric, phenyl malonic, dimethylmaleic, itaconic, mesaconic, citraconic, terephthalic, acetone dicarboxylic, diglycolic, dilactic, dihydracrylic, sulphonyl - diglycolic, tartaric, citric and p tricarballylic.  Representative alcohols are allyl, methallyl, ethylallyl, crotyl, cinnamyl, 2-chlorallyl, chlorocrotyl, methylvinylcarbinyl, tiglyl, 3-hydroxybuten-1, 3-hydroxypentadien-1,4, 1-hydroxyhexadien-2, 1 - hydroxy - 2 - methyl - hexen - 2, cyclohexenol, oleyl, geraniol, linalool and diallyl carbinol.  Halogenated epoxides include epichlorhydrin, epibromhydrin, b -methyl or ethyl derivatives thereof, 2,3-epoxy-1-chlorbutane, 1,2-epoxy-3-chlorbutane, 2,3 - epoxy - 4 - chlorpentane, 1,2-epoxy-3-chlor-2-methyl-butane, 1,2-epoxy-4-chlorbutane, 2,3 - epoxy - 4 - chlorpentane, 1,2-epoxy-3-chlor-3-phenylpropane, 2,3-epoxy-4-chlor-4-phenyl butane, chlorcyclohexene oxide and chlorcyclopentene oxide. Preferred esters are glycidyl alkenyl esters where the alkenyl group has 3-10 carbon atoms and, in particular, is allyl.  The esters may contain only one carboxyl ester group as in glycidyl acrylate, methacrylate, crotonate, oleate or linoleate.  Acids of drying oils such as linseed, tung and dehydrated castor give suitable esters.  The esters may be polymerized first through the opoxide or olefinic group only, and further polymerized through the other group or subjected to both polymerizations simultaneously.  Preferably, they are polymerized using a Friedel-Crafts' catalyst, especially 1-10 per cent of stannic chloride, and a solvent such as petroleum ether, temperatures being -50 DEG  to 100 DEG , preferably 0-60 DEG  C.  Activated clays may also be used to give the epoxide coupling.  Further olefinic polymerization may be effected with 0.1-10 per cent of a peroxide catalyst at 50-300 DEG  C. giving an insoluble, infusible polymer. This may be done after the initial polymer has been used for surface coating, for impregnating laminated sheets or introduced into moulding operations.  Alternatively, linear polymers obtained by olefinic addition may be baked at 150-300 DEG  C. to give the insoluble polymers or the esters may be mixed with peroxide catalysts and the Friedel-Crafts' catalysts then added.  The esters may be copolymerized with alkylene oxides or epichlorhydrin or compounds containing a vinylidene group such as styrene, acrylonitrile, vinyl chloride or acetate, methyl methacrylate and diallyl phthalate.  In examples: (4) glycidyl allyl phthalate is treated with stannic chloride in chloroform, the polymer separated, and baked after adding benzoyl peroxide; (5) the ester is polymerized with benzoyl peroxide, and a solution of the polymer used for coating metal strips which are then baked; (6) the initial polymer of (4) is used in solution for coating metal strips, and baked, benzoyl peroxide optionally being present; (7) stannic chloride is added to the polymer solution of (5).ALSO:An ester containing a radical R having an olefinic linkage therein, and a radical R1 containing an epoxide group, these radicals being separated by a carboxyl ester group as in the formula <FORM:0638516/IV (b)/1> is prepared by reacting a salt of a compound containing a carboxylic acid group and an olefinic linkage with a halide of an epoxide alcohol.  Preferably R is <FORM:0638516/IV (b)/2> wherein R11, R111 are a divalent and a monovalent hydrocarbon radical respectively.  The compounds include mixed esters of polycarboxylic acids wherein the hydrogen of one carboxyl group is replaced by the radical of a monohydric alcohol containing a 1,2-epoxide group, such as glycidol, and of another carboxyl group is replaced by the radical of a monohydric alcohol of 2-18 carbon atoms containing an olefinic linkage.  Any further carboxyl groups may be free or esterified with a saturated hydrocarbon radical.  The esters may be formed by first esterifying the acid with the olefinic alcohol to give a monoester, a metal salt of which is reacted with a halogenated p  epoxide.  Preferably acids which form anhydrides are used and are reacted as such, e.g. maleic, phthalic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, mono- and poly-chlorphthalic, and mono- and di-chlormaleic.  A more general method of formation of the monoesters consists in heating the diester of the acid and the olefinic alcohol with an equimolar quantity of the free acid.  The monoester is also formed by esterifying the acid with the unsaturated alcohol in the presence of at least an equimolar amount of the corresponding diester and an esterification catalyst such as a strong acid.  Other acids which may be treated include oxalic, malonic, fumaric, phenyl malonic, dimethylmaleic, itaconic, mesaconic, citraconic, terephthalic, acetone dicarboxylic, diglycolic, dilactic, dihydracrylic, sulphenyl-diglycolic, tartaric, citric, and tricarballylic.  Representative alcohols are allyl, methallyl, ethylallyl, crotyl, cinnamyl, 2-chlorallyl, chlorocrotyl, methylvinylcarbinyl, tiglyl, 3-hydroxybuten-1, 3-hydroxypentadien-1,4, 1-hydroxyhexadien-2, 1-hydroxy-2-methylhexen-2, cyclohexenol, oleyl, geraniol, linalool, and diallyl carbinol.  Metal salts of the acid esters prepared as above are formed by neutralizing with such a base as sodium, potassium, calcium, barium, strontium or magnesium carbonate, bicarbonate or hydroxide.  They are reacted with halogenated epoxides such as epichlorhydrin, epibromhydrin, b -methyl or ethyl derivatives thereof, 2,3-epoxy-1-chlorbutane, 1,2-epoxy-3-chlorbutane, 2,3-epoxy - 4 - chlorpentane, 1,2 - epoxy - 3 - chlor-2 - methyl - butane, 1,2 - epoxy - 4 - chlorbutane, 2,3 - epoxy - 4 - chlorpentane, 1,2-epoxy - 3 - chlor - 3 - phenylpropane, 2,3-epoxy - 4 - chlor - 4 - phenyl butane, chlorcyclohexene oxide, and chlorcyclopentene oxide. Preferred esters are glycidyl alkenyl esters where the alkenyl group has 3-10 carbon atoms and, in particular, is allyl.  The esters may contain only one carboxyl ester group as in glycidyl acrylate, methacrylate, crotonate, oleate or linoleate.  Acids of drying oils such as linseed, tung, and dehydrated castor give suitable esters. The esters may be polymerized first through the epoxide or olefinic group only, and further polymerized through the other group or subjected to both polymerizations simultaneously (see Group IV (a)). In examples: (1) maleic anhydride and allyl alcohol are heated to give allyl hydrogen maleate which is neutralized with potassium carbonate, further allyl alcohol and then epichlorhydrin added with heating, and glycidyl allyl maleate and diallyl maleate recovered by fractionation; (2) allyl hydrogen phthalate, prepared from phthalic anhydride and allyl alcohol, is converted to the sodium salt and converted with epichlorhydrin to glycidyl allyl phthalate; (3) the same ester is made without isolation of the intermediate metal salt; (4) the ester is treated with stannic chloride in chloroform, the polymer separated, and baked after adding benzoyl peroxide; (5) the ester is polymerized with benzoyl peroxide, and a solution of the polymer used for coating metal strips which are then baked; (6) the initial polymer of (4) is used in solution for coating metal strips, and baked, benzoyl peroxide optionally being present; (7) stannic chloride is added to the polymer solution of (5).  The Specification as open to inspection under Sect. 91 comprises also production of the mixed esters by reacting a metal salt of a polycarboxylic acid with a limited amount of halogenated epoxide to give a salt of the ester, e.g. disodium adipate and epichlorhydrin give glycidyl sodium adipate, acidifying with sulphuric acid to give, e.g. glycidyl hydrogen adipate which is reacted with vinyl or other olefinic acetate ester, e.g. isopropenyl, allyl, cinnamyl or butadienyl acetate, to give the desired ester by interchange reaction. Sulphuric acid and mercuric acetate, together with a polymerization inhibitor are added.  Glycidic and like epoxy-mono-carboxylic acids may be prepared by reacting the corresponding olefinic acids with hypochlorous acid and treating with lime to close the epoxide ring. The epoxide-acid is then esterified with the unsaturated alcohol or an alkali salt reacted with the halide of the alcohol. This subject-matter does not appear in the Specification as accepted.