Adhesive resin layer, adhesive resin film, laminate, and method of producing laminate

1. A monolayered adhesive resin layer comprising an acrylic-based adhesive resin composition having transparency, wherein

said adhesive resin composition consists essentially of (A) an acrylic-based polymer, (B) an acrylic-based monomer, and (C) a thermopolymerization initiator, wherein

said (B) acrylic-based monomer is a monomer of (meth)acrylate having a hydroxyl group which is at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctane (meth)acrylate, and cyclohexanedimethanol mon(meth)acrylate,

said adhesive resin composition contains 4 to 10 parts by weight of said (B) acrylic-based monomer based on 100 parts by weight of said (A) acrylic-based polymer, and

said adhesive resin layer has pressure sensitive adhesiveness on both surfaces at an ambient temperature, and can be thermally cured by heating at a temperature of 100 to 250° C. and a time of 30 seconds to 10 minutes.

2. The monolayered adhesive resin layer according to claim 1 , wherein said thermopolymerization initiator is a peroxide.

3. The monolayered adhesive resin layer according to claim 1 , wherein a storage elastic modulus at a temperature of 23° C. after thermal curing by heating is higher than a storage elastic modulus at a temperature of 23° C. before said heating, a storage elastic modulus at a temperature of 23° C. before heating is 1×10 4 to 1×10 6 Pa, and a storage elastic modulus at a temperature of 23° C. after thermal curing by said heating is 1×10 4 to 1×10 9 Pa.

4. An adhesive resin film comprising the monolayered adhesive resin layer according to claim 1 laminated between two separators.

5. A laminate comprising two substrates laminated with the monolayered adhesive resin layer according to claim 1 interposed between the two substrates.

6. The laminate according to claim 5 , wherein at least one substrate of said two substrates comprises one or more level differences of 5 μm to 1 mm in a surface on a side contacting with said adhesive resin layer.

7. The laminate according to claim 6 , wherein said level difference is 50 μm to 1 mm.

8. A method of producing a laminate, comprising:

laminating two substrates with the monolayered adhesive resin layer according to claim 1 interposed between the two substrates; and

thermally curing said adhesive resin layer in a state where the resulting laminate is held between two dies.

9. The method of producing a laminate according to claim 8 , wherein when a boiling point of a solvent contained in a raw material composition of said adhesive resin layer is expressed as “Temperature A”, a temperature at which said thermopolymerization initiator has a half-life of 1 minute is expressed as “Temperature B”, a temperature at heating for removing said solvent in the step of producing said adhesive resin layer is expressed as “Temperature C”, and a pressing temperature of a die in the step of thermally curing said adhesive resin layer is expressed as “Temperature D”, each temperature is in an order of an equation (1) below:

Temperature A<Temperature C<Temperature B<Temperature D.   Equation (1)

10. The method of producing a laminate according to claim 8 , wherein at least one substrate of said two substrates comprises one or more level differences of 5 μm to 1 mm in a surface on a side contacting with said adhesive resin layer.

11. The method of producing a laminate according to claim 10 , wherein said level difference is 50 μm to 1 mm.

12. The method of producing a laminate according to claim 8 , wherein a temperature of the die upon said thermal curing is a temperature of 150 to 300° C.