Lintec Corporation

Kazuhiro Tsuda

Kiichiro Kato

Osamu Kanazawa

Yumiko Matsubayashi

To produce a pressure-sensitive adhesive sheet according to which air entrapment and blistering can be prevented or eliminated through through-holes, and yet the through-holes are not readily visible at a substrate surface, a pressure-sensitive adhesive surface of a pressure-sensitive adhesive layerin a laminate comprising a substrateand the pressure-sensitive adhesive layeris irradiated with a COlaser having a pulse width of from 1 to 140 &#x3bc;sec, a pulse energy at each processing point of from 0.01 to 3.0 mJ, and a beam spot diameter at each processing point of from 30 to 160 &#x3bc;m, so as to form through-holeshaving a diameter at the surface of the substrateof from 0.1 to 42 &#x3bc;m at a hole density of from 30 to 50,000 per 100 cm.

Method of producing pressure-sensitive adhesive sheet

A pressure-sensitive adhesive layeris formed on a release treated surface of a release liner, and gas from holesin the release lineris made to move to the outside of the pressure-sensitive adhesive layer, thus forming through holesin the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layerand a base materialhaving provided therein gas-passing channels that communicate to the outside of the pressure-sensitive adhesive sheet are then laminated together such that the gas-passing channels in the base materialand the through holesin the pressure-sensitive adhesive layercommunicate with one another, thus obtaining a pressure-sensitive adhesive sheet. According to the pressure-sensitive adhesive sheet, air entrapment and blistering can be prevented or eliminated while securing adequate adhesive strength and with no marring of the appearance.

Pressure-sensitive adhesive sheet and method of manufacturing the same

To provide a pressure-sensitive adhesive sheet according to which air entrapment and blistering can be prevented or eliminated via through-holes, and yet the appearance compares favorably with that of a pressure-sensitive adhesive sheet having no through-holes therein, as a substratethere is used one having a surface roughness (Ra) of not less than 0.03 &#x3bc;m, a lightness (L*) in the L*a*b* color system of not more than 60 in the case of having a chroma (C*) of not more than 60 and a lightness (L*) of not more than 85 in the case of having a chroma (C*) greater than 60, and a contrast ratio of not less than 90%, through-holespassing through the substrateand a pressure-sensitive adhesive layerare made to have a diameter in the substrateand the pressure-sensitive adhesive layerof from 0.1 to 200 &#x3bc;m, a diameter at a surface of the substrateof from 0.1 to 42 &#x3bc;m, and a hole density of from 30 to 50,000 per 100 cm, in the case that melted portions formed by a laser are present around the through-holesat the surface of the substrate, the melted portions are made to have an outside diameter of not more than 50 &#x3bc;m, and in the case that thermally deformed portions are present around the through-holesat the surface of the substrate, the thermally deformed portions are made to have an outside diameter of not more than 180 &#x3bc;m.

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Warabi, Japan

Kazuhiro Tsuda