The Mead Corporation

Paul D Davis

Jacqueline G Truini

Paul C Adair

Gary F Hillenbrand

David A Hutchings

Gary B Schuster

Joseph G O'Connor

Jesse Hipps, Sr

Michael S Shanklin

Al Fentiman

The present invention is directed to an improved method for forming photosensitive microcapsules and increasing sensitivity by incorporating a thiol into the microcapsules through diffusion while maintaining an aqueous surrounding medium at a pH of 7.0 or less.

Method for preparing photosensitive microcapsules

A photohardenable composition comprising a free radical addition polymerizable or crosslinkable compound, an ionic dye/reactive counter ion complex capable of absorbing actinic radiation and producing free radicals which initiate free radical polymerization or crosslinking of the polymerizable or crosslinkable compound, and a disulfide represented by the structure ##STR1## wherein X is selected from the group consisting of S and O except in a specific case in which the disulfide is derived from one or more tetrazolyl groups; n represents 0 or 1; A represents the residue of the ring containing the N, C and X atoms, the ring containing five or six members and, in addition, said ring members may be fused to an aromatic ring; and R.sup.5 is an aromatic radical selected from the group consisting of (i) phenyl, (ii) benzothiazolyl, (iii) benzoxazolyl, (iv) tetrazolyl, (v) pyridinyl, (vi) pyrimidinyl, (vii) thiazolyl, (viii) oxazolyl, (ix) quinazolinyl, and (x) thiadiazolyl, each of which may have a substituent on one or more C or N atoms of the ring.

Photoinitiator compositions containing disulfides and photohardenable

A photohardenable composition comprising a free radical addition polymerizable or crosslinkable compound, a cationic dye-borate anion complex, and a borate salt, said complex being capable of absorbing actinic radiation and producing free radicals which initiate free radical polymerization or crosslinking of said compound.

Photohardenable compositions containing a borate salt

A photoinitiator composition comprising a compound which absorbs actinic radiation and directly or indirectly generates free radicals, and an O-acylthiohydroxamate compound or an N-alkoxypyridine thione; photohardenable compositions containing that photoinitiator composition; and photosensitive materials employing same.

Photoinitiator compositions containing O-acylthiohydroxamate or an

Imaging materials employing photosensitive microcapsules having improved film speed are disclosed wherein the microcapsules contain a photoinitiator system including an absorber, a coinitiator and an autoxidizer; the absorber is a compound such as an aromatic ketone, the coinitiator and the autoxidizer are different but may be compounds such as N,N-dialkylanilines; the coinitiator and autoxidizer are selected such that free radical generation and oxygen consumption occur with optimum efficiency thereby providing an imaging material having high film speed.

Imaging material employing photosensitive microcapsules containing

An imaging material comprising a support and a layer of photosensitive microparticles on one surface of said support, said microparticles including an image-forming agent and a photosensitive composition containing a polymer which is capable of undergoing cationically-initiated depolymerization and a photoinitiator including a silver halide and an organo silver salt, wherein, after exposing said microparticle to radiation, said microparticles, directly or with additional processing, release said image-forming agent or become permeable to a developer which reacts with said image-forming agent to form a visible image.

Imaging materials employing microparticles including a silver initiator

Game board

Imaging systems employing photosensitive microcapsules having improved film speed are disclosed wherein the microcapsules contain a photosensitive composition in which the photoinitiator system includes a photobleachable sensitizer such as a 3-substituted coumarin compound; the invention is particularly useful in providing self-contained imaging systems which are sensitive at 390-500 nm but which can be photobleached to reduce background yellow; an imaging process including a photobleaching step following exposure and development is also disclosed.

Growing community of inventors

Centerville, OH, United States of America

Paul D Davis