Vinyl ester resins containing mesogenic/rigid rodlike moieties

A thermosettable vinyl ester composition containing a mesogenic or rigid rodlike moiety which is prepared by reacting

• (A) a polyepoxide composition comprising
• (1) one or more advanced epoxy resins prepared by reacting
• (a) one or more epoxy resins containing an average of more than one vicinal epoxide group per molecule wherein from about zero to 100 percent of such epoxy resins contain a mesogenic or rigid rodlike moiety;
• with
• (b) at least one compound having an average of more than one phenolic hydroxyl group per molecule or an average of more than one carboxylic acid group per molecule, or a combination thereof;
• wherein at least one of components (a) or (b) contains a mesogenic or rigid rodlike moiety;
• (2) optionally one or more compounds containing only one vicinal epoxide group per molecule wherein from zero to 100 percent of such monoepoxide compounds contain a mesogenic or rigid rodlike moiety;
• and, optionally,
• (3) one or more epoxy resins containing an average of more than one vicinal epoxy group per molecule and which do not contain a mesogenic or rigid rodlike moiety;
• with
• (B) one or more polymerizable monounsaturated monocarboxylic acids;
• and
• wherein from about 1 to about 100 percent of the molecules of components (a) and (b) contain a mesogenic or rigid rodlike moiety;
• components (A) and (B) are present in quantities which provide a ratio of carboxylic acid groups per epoxide group of from about 0.9:1 to about 1.1:1;
• components (a) and (b) are present in amounts which provide a ratio of phenolic hydroxyl groups of carboxylic acid groups or combination of such groups per epoxy group of from about 0.01:1 to about 0.90:1;
• component (2) is present in an amount of from about zero to about 95 percent by weight based upon the combined weight of components (1), (2) and (3);
• and component (3) is present in an amount of from about zero to about 90 percent by weight based upon the combined weight of components (1), (2) and (3);
• but with the proviso that said advanced epoxy resin of component (A1) is, when the amount of component (A2) is zero:
• (i) other than the advanced epoxy resin prepared by reacting 4,4'-dihydroxybiphenyl with the diglycidyl ether of 4,4'-dihydroxybiphenyl;
• and
• (ii) other than the advanced epoxy resin prepared by reacting any 4,4'-dihydroxychalcone compound with the diglycidyl ether of any 4,4'-dihydroxychalcone compound wherein the alkenyl group(s) of the chalcone moiety contain(s) only hydrogen or monoalkyl or monoaryl substituents.