	US 12,410,348 B2
	Isocyanate-based adhesive
Megumi Abe, Hiratsuka (JP); and Yuichi Matsuki, Hiratsuka (JP)
Assigned to SIKA TECHNOLOGY AG, Baar (CH)
Appl. No. 17/624,889
Filed by SIKA TECHNOLOGY AG, Baar (CH)
PCT Filed Jul. 2, 2020, PCT No. PCT/JP2020/026085 § 371(c)(1), (2) Date Aug. 3, 2022, PCT Pub. No. WO2021/006187, PCT Pub. Date Jan. 14, 2021.
Claims priority of application No. 2019-126348 (JP), filed on Jul. 5, 2019.
Prior Publication US 2022/0372352 A1, Nov. 24, 2022
Int. Cl. C09J 175/04 (2006.01); C08G 18/10 (2006.01); C08G 18/32 (2006.01); C08G 18/48 (2006.01); C08G 18/66 (2006.01); C08G 18/73 (2006.01); C08K 3/04 (2006.01); C08K 3/26 (2006.01); C09J 9/00 (2006.01); C09J 11/04 (2006.01)

CPC C09J 175/04 (2013.01) [C08G 18/10 (2013.01); C08G 18/3206 (2013.01); C08G 18/4854 (2013.01); C08G 18/6607 (2013.01); C08G 18/73 (2013.01); C09J 9/00 (2013.01); C09J 11/04 (2013.01); C08G 2170/00 (2013.01); C08K 3/04 (2013.01); C08K 2003/265 (2013.01); C09J 2301/408 (2020.08)]

8 Claims

1. An isocyanate-based adhesive used for a surface-treated crystalline thermoplastic resin base material, the isocyanate-based adhesive comprising:

a main agent containing a urethane prepolymer; and

a curing agent containing a tri- or higher functional polyol having a weight average molecular weight of 1000 or less,

wherein:

a ratio of a mixed amount of the curing agent to a mixed amount of the main agent is, in terms of mass ratio, 1.1 or less,

the isocyanate-based adhesive contains no terpene compounds,

the isocyanate-based adhesive has a value represented by Formula (A) of 2.0 to 70 after being cured by being allowed to stand still under a condition at 23° C. and 50% RH for 3 days, and

the crystalline thermoplastic resin base material has a value represented by Formula (B) of 2.0 to 30.0:

Formula (A)=(JIS-A hardness)/(strength at break [MPa])×(elongation at break (%))/100

Formula (B)=δ^d/δ^p+δ^p

where δ^p=γ^p−γ^p0and δ^d=|γ^d−γ^d0|,

γ^p0is a polar term of surface free energy of a crystalline thermoplastic resin base material before the surface treatment,

γ^pis a polar term of the surface free energy of the crystalline thermoplastic resin base material after the surface treatment,

γ^d0is a dispersion term of the surface free energy of the crystalline thermoplastic resin base material before the surface treatment, and

γ^dis a dispersion term of the surface free energy of the crystalline thermoplastic resin base material after the surface treatment.