Curable composition for adhesive agents, adhesive sheet, cured article, laminate, and device

A method for producing an adhesive layer, the method comprising using a curable composition comprising a polyorganosilsesquioxane comprising:

• a constituent unit represented by Formula (I):
• [RaSiO3/2] (I)
• wherein Ra is selected from:
• an unsubstituted phenyl group;
• a group represented by Formula (1a):
• wherein R1a represents an ethylene group;
• and
• a group represented by Formula (1d):
• herein R1d represents an ethylene group;
• wherein at least one constituent unit represented by Formula (I) has Ra as the group represented by Formula (1a) or the group represented by Formula (1d);
• a constituent unit represented by Formula (II):
• [RbSiO2/2(ORc)] (II)
• wherein Rb is selected from:
• an unsubstituted phenyl group;
• a group represented by Formula (1a):
• wherein R1a represents an ethylene group;
• and
• a group represented by Formula (1d):
• wherein R1d represents an ethylene group, and
• Rc represents a hydrogen atom or an alkyl group having from 1 to 4 carbons;
• and
• wherein at least one constituent unit represented by Formula (II) has Rb as the group represented by Formula (1a) or the group represented by Formula (1d);
• wherein a molar ratio of the constituent unit represented by Formula (I) to the constituent unit represented by Formula (II), (the constituent unit represented by Formula (I))/(the constituent unit represented by Formula (II)), is from 20 to 21,
• wherein a proportion of the constituent unit represented by Formula (I) having Ra as the group represented by Formula (1a) or the group represented by Formula (1d) and the constituent unit represented by Formula (II) having Rb as the group represented by Formula (1a) or the group represented by Formula (1d) is from 95 to 99 mol % relative to a total amount (100 mol %) of siloxane constituent units,
• wherein a proportion of the constituent unit represented by Formula (I) having Ra as an unsubstituted phenyl group and the constituent unit represented by Formula (II) having Rb as an unsubstituted phenyl group is from 1 to 5 mol % relative to a total amount (100 mol %) of siloxane constituent units,
• wherein a number average molecular weight is from 3000 to 8000,
• wherein a molecular weight dispersity, (weight average molecular weight/number average molecular weight), is from 2.14 to 2.5,
• wherein a content of the polyorganosilsesquioxane is 90 wt. % or greater but less than 100 wt. %, relative to a total amount of the curable composition excluding a solvent, and
• the curable composition further comprises a polymerization stabilizer,
• wherein the polymerization stabilizer comprises a sulfonium sulfate-based compound.