Patent GB-815902-A (GB)
Title: Improvements in or relating to polyesters
IPC: C08G63/40
Filed: 1955-06-07
Abstract: Polyesters having the general formula R3OOC-R2-COO-R1-OOC-R-COOR1-OOC -R2-COO-R3 wherein R and R2 represent the same or different saturated or unsaturated aliphatic or isocyclic hydrocarbon radicals having at least 2 carbon atoms, R1 is a C2-4 alkylene radical and R3 represents an aliphatic C1-18 hydrocarbon radical are prepared by heating a molar proportion of a di-o -halogen ester of the general formula Hal-R1-OOC-R-COOR1-Hal with two molar proportions of an alkali metal salt of the formula Me-OOC-R2-COOR3, the Rs having the above meaning, at an elevated temperature.  Temperatures of 120-170 DEG  C. may be used in the presence or absence of a solvent, e.g. a mono- or poly-hydric alcohol.  Reaction may be effected in an autoclave. Those esters wherein R, R1 and R2 are as above defined and R3 represents an ethylenically unsaturated C2-18 aliphatic hydrocarbon radical and those in which R1 and R3 are as first defined above and R and R2 represent aromatic or ethylenically unsaturated aliphatic hydrocarbon radicals, are claimed per se.  The esters may be used in the plasticizing of vinyl polymers such as polyvinyl acetate and polyvinyl chloride; those esters containing unsaturated groups have a thermal stabilizing effect on polyvinyl chloride.  In examples: (1) terephthalic acid-di-b -chlor ethyl ester is reacted with two mols. of the sodium salt of phthalic acid-mono-2-ethyl hexyl ester; (2) phthalic acid-di-b -chloro ethyl ester is reacted with two mols. of the sodium salt of phthalic acid mono-butyl ester; (3) maleic acid-di-b -chlorethyl ester is reacted with 2 mols. of the potassium salt of the acid ester of (1); (4) as in (2) using, however, the potassium salt of the acid-ester with sebacic acid di-b -chloroethyl ester and the product is used to plasticise polyvinyl acetate or chloride; (5) phthalic acid di-b -chloroethyl ester is reacted with 2 mols. of the potassium salt of maleic acid mono-2-ethyl hexyl ester; (6) maleic acid di-b -chlor ethyl ester is reacted with two mols. of the potassium salt of maleic acid monoallyl ester; (7) terephthalic acid di-b -chlor ethyl ester is reacted with the allyl ester salt of (6); (8) maleic acid di-b -chlor ethyl ester is reacted with 2 mols. of the sodium salt of maleic acid mono-2-ethylhexyl ester. Many other reagents are mentioned including di-b -chlor-isopropyl, di-g -chlor propyl and di-d -chlor butyl esters of appropriate dibasic acids and semi-ester salts of hydrophthalic, glutaric, fumaric, suberic and naphthalene-1:4-dicarboxylic acids, oleyl esters inter alia being referred to.ALSO:The invention comprises a method for the preparation of polyesters of the general formula <FORM:0815902/IV (b)/1> wherein R and R2 represent the same or different saturated or unsaturated aliphatic or isocyclic hydrocarbon radicals having at least 2 carbon atoms, R1 is an alkylene group having 2-4 carbon atoms and R3 represents a monovalent aliphatic hydrocarbon radical with 1-18 carbon atoms, which comprises reacting a molar proportion of a di-o -halogen ester of the formula Hal-R1-OOC-R-COOR1-Hal with two molar proportions of an alkali metal salt of the formula Me-OOC-R2-COO-R3, the R's having the above meaning, at elevated temperatures.  Reaction is preferably effected in the presence of solvents, e.g. mono- or polyhydric alcohols, and suitably at the temperature at which the alcohol boils; reaction may be effected in the presence or absence of a solvent at 120-170 DEG  C. or in an autoclave.  The product is filtered or washed to remove alkali metal halide and may then be refined with sodium carbonate and quicklime.  The invention also comprises as new compounds those esters wherein R, R1 and R2 are as above defined and R2 represents a monovalent ethylenically unsaturated aliphatic hydrocarbon radical containing 2-18 carbon atoms and those esters in which R1 and R3 are as first defined above and R and R2 represent aromatic or ethylenically unsaturated aliphatic hydrocarbon radicals.  The esters are oily to resinous products and may be used as plasticizers for vinyl polymers (see Group IV (a)).  Preferred esters are those in which R is a straight C2-8 aliphatic chain and R2 is the phenylene radical; in other preferred compounds R and/or R2 represent the phenylene radical and/or the radical -CH=CH-, or R3 represents the allyl radical.  The di-o -halogen esters used as starting materials may be prepared by azeotropic esterification with alkylene chlorhydrins or by reacting dicarboxylic acid dichlorides with alkylene oxides in the presence of alkaline catalysts.  The semi-ester salt reactants may be prepared by reacting the dicarboxylic acid anhydrides with the alcohols to form the semi-esters which are then neutralized with alkali carbonate; alternatively, the ester salts may be obtained in one step by reacting the acid anhydrides with alcoholates.  In examples: (1) phthalic anhydride is heated with 2-ethylhexanol and the resulting acid ester neutralized with Na2CO3; the salt-ester is then heated with terephthalic acid-di-b -chloroethyl ester and the reaction mixture is worked up to isolate the desired polyester; (2) phthalic anhydride is heated with sodium butoxide and the resulting ester-salt reacted with phthalic acid di-b -chloroethyl ester and the desired polyester recovered as in (1); (3) the potassium salt of the acid ester of (1) is prepared and heated with maleic acid di-b -chloroethyl ester, yielding the desired polyester; (4) as in (2) using, however, the sebacic di-ester of b -chloroethyl alcohol with the potassium salt of the acid ester; (5) maleic acid anhydride is reacted with 2-ethylhexanol and the resulting acid ester in the form of its potassium salt is reacted with phthalic acid di-b -chloroethyl ester and the resulting polyester recovered; (6) the potassium salt of the acid allyl ester of maleic acid is formed and reacted as above with maleic acid di-b -chloroethyl ester; or (7) with terephthalic acid di-b -chloroethyl ester; (8) in analogous manner a polyester is prepared from maleic anhydride, 2-ethylhexanol and maleic acid di - b - chloroethyl ester.  Numerous other reagents are mentioned including di-b -chloro-isopropyl, di-g -chloro-propyl and di-g -chloro-butyl esters of appropriate dibasic acids, and semi-ester salts of hydrophthalic, fumaric, glutaric, suberic and naphthalene 1 : 4-dicarboxylic acids, oleyl esters, inter alia, being referred to.