	US 12,404,428 B2
	Radiation-curable adhesive sheet
Shuhei Fukutomi, Ibaraki (JP); Hirofumi Katami, Ibaraki (JP); and Shinya Yamamoto, Ibaraki (JP)
Assigned to NITTO DENKO CORPORATION, Osaka (JP)
Appl. No. 18/284,135
Filed by NITTO DENKO CORPORATION, Ibaraki (JP)
PCT Filed Mar. 24, 2022, PCT No. PCT/JP2022/014047 § 371(c)(1), (2) Date Sep. 26, 2023, PCT Pub. No. WO2022/210277, PCT Pub. Date Oct. 6, 2022.
Claims priority of application No. 2021-058810 (JP), filed on Mar. 30, 2021.
Prior Publication US 2024/0182756 A1, Jun. 6, 2024
Int. Cl. C09J 7/38 (2018.01); C09J 11/06 (2006.01); C09J 133/14 (2006.01)

CPC C09J 7/385 (2018.01) [C09J 11/06 (2013.01); C09J 133/14 (2013.01)]

14 Claims

1. A pressure-sensitive adhesive sheet, comprising:

i) a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer comprising, in polymerized form, a base monomer, a first photopolymerization initiator and a first crosslinking agent, the pressure-sensitive adhesive layer having two opposite principal surfaces: first principal surface and second principal surface;

ii) a second photopolymerization initiator;

iii) a second crosslinking agent, and

iv) a release sheet laminated onto the first principal surface of the pressure-sensitive adhesive layer, wherein:

when the pressure-sensitive adhesive layer is stored at 50° C. for 4 weeks, a rate of change in residual stress (N/cm²) expressed by the following equation is 70% or less:

residual stress change rate (%)=(residual stress after storage at 50° C. for 4 weeks−initial residual stress)/(initial residual stress)×100, and

the first crosslinking agent forms a crosslinked structure in the pressure-sensitive adhesive layer, while the second crosslinking agent is an unreacted crosslinking agent and is present within the pressure-sensitive adhesive layer and the second photopolymerization initiator is an unreacted photopolymerization initiator and is present within the pressure-sensitive adhesive layer.