Patent ID: 6151042
Filing Date: 2000-11-21
Classification: B41J,G03F,Y10S

Abstract:
An ink jet printhead which comprises (i) an upper substrate with a set of parallel grooves for subsequent use as ink channels and a recess for subsequent use as a manifold, the grooves being open at one end for serving as droplet emitting nozzles, (ii) a lower substrate in which one surface thereof has an array of heating elements and addressing electrodes formed thereon, and (iii) a layer deposited on the surface of the lower substrate and over the heating elements and addressing electrodes and patterned to form recesses therethrough to expose the heating elements and terminal ends of the addressing electrodes, the upper and lower substrates being aligned, mated, and bonded together to form the printhead with the grooves in the upper substrate being aligned with the heating elements in the lower substrate to form droplet emitting nozzles, said layer comprising 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 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, polycarbonates, polyether imides, polyquinoxalines, polyquinolines, polybenzimidazoles, polybenzoxazoles, polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixtures thereof, 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.