Low-hardness solvent-proof polyurethane elastomer and preparation method thereof

The invention discloses a low-hardness solvent-proof polyurethane elastomer and a preparation method thereof. The raw material of the low-hardness solvent-proof polyurethane elastomer comprises two parts including a component A and a component B, wherein the component A comprises 100 parts of polyester polyatomic alcohol, 15 to 30 parts of toluene diisocyanate, 0 to 20 parts of soften flux, and 3 to 10 parts of filling material; the component B comprises 100 parts of chain extendor, 0 to 0.5 part of foam killer, and 0.02 to 0.05 part of catalyst. The chain extendor is composed of an alcohol amine chain extendor and a three-functionality alcohol chain extendor, wherein the alcohol amine chain extendor adopts a mixture of TIPA (triisopropanolamine) and DEA (diethanol amine) or TEA ( triethavolamine), and the mixture molar ratio is 1 to 0.5-1.5; the three-functionality alcohol chain extendor is made of GLY (glycerine),TMP (trimethylolpropane) or TME (trimethylolethane); the molar ratio of the three-functionality alcohol chain extendor to the alcohol amine mixture is 1 to 0.25-1.5. The material has a better mechanical property, and better solvent resisting performance and cutting machinability, and can be used in the fields of color coating and the like.