PRESSURE-SENSITIVE ADHESIVE COMPOSITION AND PRESSURE-SENSITIVE ADHESIVE SHEET

• Main Authors: TAMURA JUNKO, FUKUTA KATSUNORI
• Format: Patent
• Language: English; Japanese
• Published: 17.06.2021
• 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

To provide a pressure-sensitive adhesive sheet not only excellent in repeelability and stain resistance which are the required qualities necessary for a surface protection sheet for process conservation but also superior in adhesiveness and durability necessary for the sheet for product protection compared to the conventional sheet and enables compatibility for both process and product protection, and to provide the adhesive composition capable of forming the above adhesive sheet.SOLUTION: An objective pressure-sensitive adhesive composition includes an acrylic copolymer (A) and a hardener (B). The acrylic copolymer (A) is the copolymer of a monomer mixture including (a-1) to (a-4) mentioned below. (a-1): (meth)acrylic alkyl ester having 4-8C alkyl groups, (a-2): (meth)acrylic alkyl ester having hydroxyl groups, (a-3): (meth)acrylic alkyl ester having an alicyclic structure and (a-4): N-substituted (meth)acrylic amide. The copolymer (A) includes (a-3) of 10 mass% or more but less than 30 mass% and (a-4) of 5 mass% or more but less than 20 mass% in 100 mass% of the monomer mixture. The content of the hardener (B) is 0.1 pts.mass or more but 10 pts.mass or less based on 100 pts.mass of the acrylic copolymer (A).SELECTED DRAWING: None 【課題】工程保護用表面保護シートに必要な要求品質である再剥離性および耐汚染性に優れるだけでなく、製品保護用表面保護シートに必要な密着性および耐久性も従来より優れており、これまでの粘着シートでは難しかった、工程保護用と製品保護用との両立が可能な粘着シートと、該粘着シートを形成することができる粘着剤の提供を目的とする。【解決手段】アクリル系共重合体（Ａ）と硬化剤（Ｂ）とを含み、前記アクリル系共重合体（Ａ）は、（ａ−１）〜（ａ−４）を含むモノマー混合物の共重合体であり、かつ前記モノマー混合物１００質量％中に（ａ−３）を１０質量％以上３０質量％未満、および（ａ−４）を５質量％以上２０質量％未満含み、前記硬化剤（Ｂ）の含有量は、アクリル系共重合体（Ａ）１００質量部に対し、０．１質量部以上１０質量部以下である、粘着剤組成物により解決される。【選択図】 なし