Patent ID: 6323301
Filing Date: 2001-11-27
Classification: B41J,G03F,Y10S

Abstract:
A crosslinked or chain extended polymer formed by crosslinking or chain extending a precursor polymer with a weight average molecular weight of from about 1,000 to about 100,000, said precursor polymer having terminal end groups and monomer repeat units, said crosslinking or chain extension occurring through first, photosensitivity-imparting substituents pendant from at least some of the monomer repeat units of the precursor polymer which form crosslinks or chain extensions in the precursor polymer upon exposure to actinic radiation, said precursor polymer also containing a second, thermal sensitivity-imparting substituent, present as (1) at least one terminal end group, (2) a substituent pendant from one or more of the monomer repeat units, or (3) a combination of (1) and (2), which enables further crosslinking or chain extension of the precursor polymer upon exposure to temperatures of about 140.degree. C. and higher subsequent to exposure to actinic radiation at a wavelength sufficient to cause crosslinking or chain extension of the precursor polymer through the first, photosensitivity-imparting substituents, wherein the first substituent is not the same as the second substituent, said second, thermal sensitivity-imparting substituent being selected from the group consisting of ethynyl groups, allyl groups, vinyl groups, vinyl ether groups, benzocyclobutene groups, phenolic groups, maleimide groups, biphenylene groups, 5-norbornene-2,3-dicarboximido groups, and mixtures thereof, provided that when the thermal sensitivity imparting groups are phenolic groups, either halomethyl groups or hydroxymethyl groups are present (A) on the precursor polymer having the phenolic thermal sensitivity imparting groups, (B) on a second polymer admixed with the precursor polymer having the phenolic thermal sensitivity imparting groups, or (C) on a monomeric species admixed with the precursor polymer having the phenolic thermal sensitivity imparting groups, said precursor polymer being selected from the group consisting of polysulfones, polyphenylenes, polyether sulfones, polyimides, polyamide imides, polyarylene ethers, polyphenylene sulfides, polyarylene ether ketones, phenoxy resins, polycorbonates, polyether imides, polyquinoxalines, polyquinolines, polybenzimidazoles, polybenzoxazoles, polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixtures thereof, said crosslinking or chain extending being effected by (i) first exposing the precursor polymer to actinic radiation at a wavelength sufficient to cause crosslinking or chain extension of the precursor polymer through the first, photosensitivity-imparting substituents, and (ii) exposing the precursor polymer to temperatures of about 140.degree. C. or higher subsequent to exposure to actinic radiation to cause further crosslinking or chain extension of the precursor polymer through the second, thermal sensitivity-imparting substituent, wherein either (a) the first, photosensitivity-imparting substituent and the second, thermal sensitivity-imparting substituent are selected so that the second, thermal sensitivity imparting group does not react or crosslink when exposed to actinic radiation at a level to which the first, photosensitivity-imparting group is sensitive, or (b) photocuring is halted while at least some of the second, thermal sensitivity imparting groups remain intact and unreacted or uncrosslinked on the precursor polymer.