| abstract |
The purpose of the present invention is to provide an isocyanate-based adhesive that exhibits superior adhesiveness, water-resistant adhesiveness, and heat-resistant adhesiveness. The present invention provides an isocyanate-based adhesive to be used in a surface-treated crystalline thermoplastic resin base material. In the isocyanate-based adhesive, the value expressed by formula (A) is 2.0-70 after being cured by being left to stand for three days under conditions of 23ºC and 50%RH. In the crystalline thermoplastic resin base material, the value expressed by formula (B) is 2.0-30.0. Formula (A) = (JIS-A hardness)/(breaking strength [MPa])×(elongation at break(%))/100. Formula (B)= δd/δp + δp, where δp=γp-γp0, δd=|γd-γd0|, γp0 is a polarity term of surface free energy before surface treatment, γp is a polarity term of surface free energy after surface treatment, γd0 is a dispersion term of surface free energy before surface treatment, and γd is a dispersion term of surface free energy after surface treatment. |