PRESSURE-SENSITIVE ADHESIVE SHEET

• Main Authors: KITAYAMA KAZUHIRO, FUKUHARA ATSUHITO, HIRAYAMA TAKAMASA
• Format: Patent
• Language: English; Japanese
• Published: 20.06.2016
• Subjects: ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; ADHESIVES; CHEMISTRY; DYES; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; PAINTS; POLISHES; USE OF MATERIALS AS ADHESIVES

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet that has both adhesiveness and releasability and can reduce unevenness generated on an adhesive surface of a workpiece (adherend).SOLUTION: The pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer includes a pressure-sensitive adhesive and thermally expansible fine spheres capable of being foamed at a predetermined temperature. The average particle size of the thermally expansible fine spheres at 25°C is 10 μm or less; the content of the thermally expansible fine spheres is 15 wt.% or more; and the elastic modulus of the pressure-sensitive adhesive layer at a temperature lower than a foaming temperature of the thermally expansible fine spheres by 20°C as measured by a nanoindentation method is 0.6 MPa to 30 MPa.SELECTED DRAWING: Figure 1 【課題】粘着性と剥離性とが両立され、かつ、該加工物（被着体）の貼着面に生じる凹凸を低減し得る粘着シートを提供すること。【解決手段】本発明の粘着シートは、粘着剤層を備える、粘着シートであって、該粘着剤層が、粘着剤と、所定温度で発泡可能な熱膨張性微小球とを含み、該熱膨張性微小球の２５℃での平均粒子径が、１０μｍ以下であり、 該熱膨張性微小球の含有割合が、１５重量％以上であり、該熱膨張性微小球の発泡温度よりも２０℃低い温度における、該粘着剤層のナノインデンテーション法による弾性率が、０．６ＭＰａ〜３０ＭＰａである。【選択図】図１