	US 12,281,193 B2
	Blocked isocyanate composition, production method thereof, curing agent for paint, paint composition and coated film
Yuji Nakashima, Yokkaichi (JP); Shuto Noguchi, Yokkaichi (JP); and Mitsushige Ikemoto, Yokkaichi (JP)
Assigned to TOSOH CORPORATION, Shunan (JP)
Filed by TOSOH CORPORATION, Shunan (JP)
Filed on Mar. 6, 2024, as Appl. No. 18/597,171.
Claims priority of application No. 2023-037806 (JP), filed on Mar. 10, 2023.
Prior Publication US 2024/0301123 A1, Sep. 12, 2024
Int. Cl. C08G 18/80 (2006.01); C09D 175/04 (2006.01)

CPC C08G 18/8077 (2013.01) [C09D 175/04 (2013.01); C08G 2150/00 (2013.01)]

7 Claims

1. A production method of a blocked isocyanate composition, comprising:

a step of mixing and reacting a polyisocyanate and an oxime-based blocking agent,

wherein a ratio of an amount of the oxime-based blocking agent mixed to an amount of the polyisocyanate mixed is 0.91 to 0.99 in terms of an equivalent ratio, and

wherein the polyisocyanate contains an aliphatic polyisocyanate having 4 to 6 carbon atoms or a derivative thereof,

wherein the blocked isocyanate composition has a free isocyanate group, and

wherein the content rate of the free isocyanate in the blocked isocyanate is from 0.1 to 1.5 mass %.