Patent GB-612312-A (GB)
Title: Improvements in or relating to the production of polymerisable esters
IPC: H01B3/44
Filed: 1945-04-17
Abstract: Allyl or methallyl alcohol esters of the Diels-Alder reaction product of maleic anhydride with an organic compound containing at least two conjugated pairs of doubly linked carbon atoms are polymerized to oils or soft resins.  Among the organic compounds which form the Diels-Alder adduct are the conjugated terpenes, e.g. a -terpinene; the conjugated cyclo-aliphatic polyenes, e.g. cyclopentadiene; anthracene; aromatic compounds having an unsaturated aliphatic side chain such as isosaffrole, a -methylstyrene; aromatic compounds containing non-aromatic unsaturation in a ring fused to an aromatic ring, such as coumarone and indene and the conjugated drying oil fatty acids and esters thereof.  Polymerization catalysts such as benzoyl peroxide may be present.  The products may be used in bonding, electrical insulating, impregnating and surface coating compositions.  Fabricated products such as brake linings or plywood may also be produced by using the polymerzedi esters as bonding agents.  In examples, the Diels-Alder reaction products of maleic anhydride with (1) a -terpinene obtained by fractionating commercial dipentene and conducting the Diels-Alder reaction in the presence of a small amount of benzoyl peroxide: (2) pure cyclopentadiene prepared from a crude sample of the dimer by depolymerization and fractionation; (3) pure anthracene, and (4) a mixture of wood oil fatty acids, are esterified with allyl alcohol and polymerized.  The product of example 3 is stated to be diallyl 1 : 4 endo-o-phenyl-1 : 2 : 3 : 4-tetrahydronaphthalene-2 : 3-dicarboxylic ester. Specifications 490,714 and 612,311 are referred to.ALSO:Polymerizable esters are produced by esterifying with allyl or methallyl alcohol the Diels-Alder reaction products of maleic anhydride with an organic compound containing at least two conjugated pairs of doubly linked carbon atoms or by effecting an alcoholysis reaction between a lower alkyl ester of the said Diels-Alder adduct and the allyl or methallyl alcohol.  Among the organic compounds which form the Diels-Alder adduct are the conjugated terpenes, e.g. a -terpinene; the conjugated cyclo-aliphatic polyenes, e.g. cyclopentadiene; anthracene; aromatic compounds having an unsaturated aliphatic side chain such as isosaffrole, a -methylstyrene; aromatic compounds containing non-aromatic unsaturation in a ring fused to an aromatic ring, such as coumarone and indene and the conjugated drying oil fatty acids and esters thereof.  The products vary from oils to soft resins of the character of balsams and can be used in bonding compositions, electrical insulating compositions and in varnish impregnating and surface coating compositions.  Fabricated products such as brake linings or plywood may also be produced by using the polymerized esters as bonding agents.  In examples, the Diels-Alder reaction products of maleic anhydride with (1) a -terpinene obtained by fractionating commercial dipentene and conducting the Diels-Alder reaction in the presence of a small amount of benzoyl peroxide; (2) pure cyclopentadiene prepared from a crude sample of the driver by depolymerization and fractionation; (3) pure anthracene, and (4) a mixture of wood oil fatty acids, are esterified with allyl alcohol. In (1) and (2), esterification is effected in the presence of a small amount of p-toluene sulphonic acid and in (3) and (4) in the presence of concentrated sulphuric acid, a little decolourising charcoal being also added in the case of (4).  The product of example (3) is stated to be diallyl 1 : 4-endo-o-phenylene-1 : 2 : 3 : 4 - tetrahydronaphthalene - 2 : 3 - dicarboxylic esters. Specifications 490,714 and 612,311 are referred to.