Carboxyl-containing compositions and their polymerization

Abstract

Polymerizable compositions comprise (a) a compound containing (i) at least one acryloyloxy or methacryloyloxy group, (ii) at least one allyl, methallyl, or 1-propenyl group attached, either directly or through an oxygen atom or an oxycarbonyl group, to a carbon atom which forms part of an aromatic or cycloaliphatic nucleus, and (iii) at least one carboxylic acid group, (b) a compound containing at least two mercaptan groups directly attached to aliphatic carbon atoms, in a proportion as to supply at least 0.8 such --SH group per allyl, methallyl, and 1-propenyl group in (a) but less than 1.0 such --SH group in (a) per acryloyl, methacryloyl, allyl, methallyl, and 1-propenyl group. Examples of (a) are 2,2-bis(3-allyl-4-(3-(methacryloyloxy)-2-(2-carboxyethylcarbonyloxy)propox y)phenyl)propane, 1-(allyloxycarbonyl)-2,4-bis(3-(methacryloyloxy)-2-(2-carboxyethylcarbonyl oxy)propoxycarbonyl)benzene, and diallyl bis(3-(methacryloyloxy)-2-(2-carboxyethylcarbonyloxy)propyl) esters of benzophenone-3,4,3',4'-tetracarboxylic acid. Examples of (b) are pentaerythritol tetrathioglycollate, trimethylolpropane trithioglycollate, and 3,6-dioxa-1,8-dimercapto-octane. The compositions may be polymerized by means of actinic irradiation in the presence of an added or "built-in" photosensitizer or by the action of a free-radical catalyst. They are especially useful in the production of printed circuits.

Dependencies are inferred from the claim text.