A main object of the present invention is to provide a receptor layer forming resin which makes it possible to obtain a receptor layer for a thermal transfer image receptor sheet having excellent dyeing property. The present invention achieves the above object by providing a receptor layer forming polyurethane resin for a thermal transfer image receptor sheet obtained by copolymerizing: a high molecular weight polyol having a number average molecular weight of 1000 or higher (A) ; an organic isocyanate (B); and according to need, a polyol compound having a number average molecular weight of 500 or lower (C), wherein the receptor layer forming polyurethane resin for a thermal transfer image receptor sheet meets the following requirements (1) to (4): (1) the resin has at least two glass transition temperatures; (2) at least one of the glass transition temperatures is between −200 to 0° C., and at least one is between 20 to 100° C.; (3) the high molecular weight polyol (A) is a mixture comprising; an aromatic polyester polyol containing metallic base sulfonate (A-1); and a polyol other than said (A-1) (A-2); and (4) the ratio of (A-2) in the high molecular weight polyol (A) is 20 mass percent or higher.
本发明的一个主要目的是提供一种受体层形成
树脂,它可以获得具有优异染色性能的热转印图像受体片的受体层。为实现上述目的,本发明提供了一种用于热转印图像感受器片材的感受器层形成聚
氨酯
树脂,该
树脂由以下物质共聚而成:平均分子量大于等于 1000 的高分子量多元醇(A);有机
异氰酸酯(B);以及根据需要,平均分子量小于等于 500 的多元醇化合物(C),其中用于热转印图像感受器片材的感受器层形成聚
氨酯
树脂满足以下要求(1)至(4):(1) 该
树脂至少有两个
玻璃化转变温度;(2) 至少一个
玻璃化转变温度在 -200 至 0 摄氏度之间,至少一个
玻璃化转变温度在 20 至 100 摄氏度之间;(3) 高分子量多元醇 (A) 是一种混合物,包括:含有
金属基
磺酸盐的芳香族聚酯多元醇 (A-1);以及除所述 (A-1) 之外的多元醇 (A-2);以及 (4) (A-2) 在高分子量多元醇 (A) 中的比例为 20 质量%或更高。