Improvements in or relating to the production of linear aromatic polyesters

摘要

Linear aromatic polyesters, suitable for the manufacture of film and fibres, are made by heating together (a) a diester of a bis-phenol or a mixture of a bis-phenol and a substance which reacts therewith to form such a diester and (b) an aromatic dicarboxylic acid having two phenylene rings or a chemically equivalent derivative thereof (e.g. an ester or anhydride); at least one of the two reactants having its two phenylene rings linked by a substituted methylene group or by means of a carbon atom forming part of a cycloaliphatic ring. Reaction may be effected in the absence or presence of a solvent (e.g. alphamethylnaphthalene, diphenyl or diphenyl oxide) or a catalyst (e.g. butyl titanate, antimony trioxide or a mixture of p-toluene sulphonic acid and antimony trioxide). Preferably the bis-phenols and dicarboxylic acid are respectively of formula and wherein one of the R and R1 linkages represents an alkyl or aryl substituted methylene group or a carbon atom forming part of a cycloaliphatic ring and the other of R and R1 also represents such a linkage or represents an oxygen atom, a carboxyl group or an unsubstituted methylene group. The Specification contains lists of suitable reactants. The polyesters are soluble in methylene chloride, chloroform, dichloroethane, tetrachloroethane, dioxane and tetrahydrofurane. Examples describe the manufacture of polyesters from (1), (2), (3) and (6). The diacetate of bisphenol A and 2,2-(4,41-dicarboxydiphenyl) propane, 4,41-dicarboxy diphenyl methane or 4,41-dicarboxy diphenyloxide; (4) The diacetate of 1-phenyl-1,1-(4,4-dihydroxydiphenyl) methane and 2,2-(4.4-dicarboxydiphenyl) propane; (5) The diacetate of 4,41-dihydroxydiphenyl-1,1-cyclohexane and 2,2-(4,41-dicarboxydiphenyl) propane. Specification 621,102 is referred to.