Adhesive agent composition, layered product and production method for layered product, and method for reducing thickness of semiconductor forming substrate

An adhesive composition for forming an adhesive layer that can bond a first substrate formed of a semiconductor-forming substrate to a second substrate formed of a support substrate in a peelable manner,

• the composition comprising
• a component (A) which is cured through hydrosilylation and
• a peeling component (B) which contains a component containing an epoxy-modified polyorganosiloxane having an epoxy value of 0.1 to 5, wherein
• the component (A) comprises
• a polysiloxane (A1) having one or more units selected from the group consisting of a siloxane unit represented by SiO2 (unit Q), a siloxane unit represented by R1R2R3SiO1/2 (unit M), a siloxane unit represented by R4R5SiO2/2 (unit D), and a siloxane unit represented by R6SiO3/2 (unit T) (wherein each of R1 to R6 is a group or an atom bonded to a silicon atom and represents an alkyl group, an alkenyl group, or a hydrogen atom) and
• a platinum group metal catalyst (A2);
• and
• the polysiloxane (A1) comprises:
• a polyorganosiloxane (a1) having one or more units selected from the group consisting of a siloxane unit represented by SiO2 (unit Q′), a siloxane unit represented by R1′R2′R3′SiO1/2 (unit M′), a siloxane unit represented by R4′R5′SiO2/2 (unit D′), and a siloxane unit represented by R6′SiO3/2 (unit T′), and at least one unit selected from the group consisting of unit M′, unit D′, and unit T′ (wherein each of R′ to R6′ is a group bonded to a silicon atom and represents an alkyl group or an alkenyl group, and at least one of R′ to R6′ is an alkenyl group), and
• a polyorganosiloxane (a2) having one or more units selected from the group consisting of a siloxane unit represented by SiO2 (unit Q″), a siloxane unit represented by R1″R2″R3″SiO1/2 (unit M″), a siloxane unit represented by R4″R5″SiO2/2 (unit D″), and a siloxane unit represented by R6″SiO3/2 (unit T″), and at least one unit selected from the group consisting of unit M″, unit D″, and unit T″, and having a functional group (Si—H) content of 5.0 mol/kg or greater (wherein each of R1″ to R6″ is a group or an atom bonded to a silicon atom and represents an alkyl group or a hydrogen atom, and at least one of R1″ to R6″ is a hydrogen atom).