Photo-crosslinkable pressure-sensitive adhesive and use thereof
AssigneeNitto Denko Corporation
InventorsRyoko Asai, Naofumi Kosaka, Yosuke Shimizu
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Abstract
Provided is a photo-crosslinkable PSA comprising a polymer having side-chain benzophenone structures. The photo-crosslinkable PSA is a cured product of a PSA composition comprising an ethylenically unsaturated compound and a benzophenone structure-containing component. The photo-crosslinkable PSA has VOC emissions of 500 μg/g or less. Also provided is a PSA sheet having a PSA layer formed from the photo-crosslinkable PSA.
Claims10
A photo-crosslinkable pressure-sensitive adhesive
- being formed from a pressure-sensitive adhesive composition comprising an ethylenically unsaturated compound and a polymer having side-chain benzophenone structures, and
- comprising a polymer having unreacted side-chain benzophenone structures, wherein the pressure-sensitive adhesive composition comprises, as the ethylenically unsaturated compound, a compound having one ethylenically unsaturated group,
- wherein, of the entire monomers forming the pressure-sensitive adhesive composition, a compound having two or more ethylenically unsaturated groups has a weight fraction of 1% by weight or lower.
A method for producing a photo-crosslinkable pressure-sensitive adhesive, the method comprising
- obtaining a pressure-sensitive adhesive composition comprising a polymer (A) having side-chain benzophenone structures, an ethylenically unsaturated compound (B), and a photoinitiator (C) that absorbs 300 nm to 500 nm wavelength light to generate radicals;
- and
- irradiating the pressure-sensitive adhesive composition with active energy rays;
- wherein the pressure-sensitive adhesive composition comprises, as the ethylenically unsaturated compound (B), a compound (B1) having one ethylenically unsaturated group,
- wherein, of the entire monomers forming the pressure-sensitive adhesive composition, a compound having two or more ethylenically unsaturated groups has a weight fraction of 1% by weight or lower, and
- wherein the active energy rays are irradiated to allow reaction of the ethylenically unsaturated group of the ethylenically unsaturated compound (B) while allowing the benzophenone structures of the polymer (A) to remain.
A pressure-sensitive adhesive composition used for producing a photo-crosslinkable pressure-sensitive adhesive comprising a polymer having benzophenone structures in side chains, the pressure-sensitive adhesive composition comprising
- a polymer (A) having benzophenone structures in side chains,
- an ethylenically unsaturated compound (B), and
- a photoinitiator (C) that absorbs 300 nm to 500 nm wavelength light to generate radicals;
- wherein the pressure-sensitive adhesive composition comprises, as the ethylenically unsaturated compound (B), a compound (B1) having one ethylenically unsaturated group, and
- wherein, of the entire monomers forming the pressure-sensitive adhesive composition, a compound having two or more ethylenically unsaturated groups has a weight fraction of 1% by weight or lower below 5% by weight.
Dependencies are inferred from the claim text.