US 12,473,471 B2
Laminate, production method therefor, and automotive exterior material
Masashi Ikeda, Tokyo (JP); Seiji Takagi, Tokyo (JP); Toru Seo, Tokyo (JP); and Jun Matsui, Tokyo (JP)
Assigned to MITSUBISHI CHEMICAL CORPORATION, Tokyo (JP)
Filed by MITSUBISHI CHEMICAL CORPORATION, Tokyo (JP)
Filed on Jun. 9, 2022, as Appl. No. 17/836,369.
Application 17/836,369 is a continuation of application No. PCT/JP2020/047656, filed on Dec. 21, 2020.
Claims priority of application No. 2019-235250 (JP), filed on Dec. 25, 2019.
Prior Publication US 2022/0298397 A1, Sep. 22, 2022
Int. Cl. C09J 163/00 (2006.01); B32B 7/027 (2019.01); B32B 7/12 (2006.01); B32B 15/01 (2006.01); B32B 37/12 (2006.01); C09J 7/21 (2018.01); C09J 7/35 (2018.01)
CPC C09J 163/00 (2013.01) [B32B 7/027 (2019.01); B32B 7/12 (2013.01); B32B 15/012 (2013.01); B32B 37/1207 (2013.01); C09J 7/21 (2018.01); C09J 7/35 (2018.01)] 14 Claims
 
1. A laminate comprising a first material, an adhesive agent layer, and a second material provided in this order,
wherein the first material and the second material have different linear expansion coefficients,
wherein the adhesive agent layer comprises an adhesive agent having a warpage reduction index of not less than 30,
wherein a content of an epoxy resin comprised in the adhesive agent is 85 mass % or more based on 100 mass % of overall resin component of the adhesive agent,
wherein the adhesive agent layer has an average storage elastic modulus of 1 to 400 MPa in a temperature range of 25° C. to 180° C.,
the warpage reduction index of the adhesive agent being determined by:
preparing an analysis model laminate having:
an aluminum plate having a width of 25 mm, a length of 100 mm, and a thickness of 1.6 mm,
a cold-rolled steel plate having a width of 25 mm, a length of 100 mm, and a thickness of 1.6 mm, and
a layer of the adhesive agent between the aluminum plate and the cold-rolled steel plate, the layer of the adhesive agent having a thickness of 0.7 mm;
preparing a reference model laminate having:
an aluminum plate having a width of 25 mm, a length of 100 mm, and a thickness of 1.6 mm, and
a cold-rolled steel plate having a width of 25 mm, a length of 100 mm, and a thickness of 1.6 mm,
wherein the reference model laminate does not have any adhesive agent between the aluminum plate and the cold-rolled steel plate;
determining a displacement amount WA at an end of the analysis model laminate by finite element structure analysis using Computer Aided Engineering (CAE) software while a middle portion of the cold-rolled steel plate is fixed in place and a temperature of the analysis model laminate is changed from a starting temperature of 180° C. to a final temperature of 25° C.;
determining a displacement amount WB at an end of the reference model laminate by finite element structure analysis using Computer Aided Engineering (CAE) software while a middle portion of the cold-rolled steel plate is fixed in place and a temperature of the reference model laminate is changed from a starting temperature of 180° C. to a final temperature of 25° C.; and
calculating the warpage reduction index from the following expression (1):
Warpage reduction index=100−(WA/WB)×100  (1).