Patent ID: 7544761

Claim:
A polythiourethane produced by a reaction of a polythiol component comprising at least one polythiocarbonate polythiol with a polyisocyanate component comprising at least one member selected from polyisocyanates and polyisothiocyanates, wherein the polythiocarbonate polythiol for the polythiol component comprises repeating units represented by the chemical formula (I): in which formula (I), R represents a divalent hydrocarbon group, which hydrocarbon group may have at least one substituent which does not take part in a reaction with the polyisocyanate component and the carbon chain in the hydrocarbon group may include at least one member selected from hetero atoms and an OCO group, and the polythiocarbonate polythiol has a number average molecular weight of 200 to 2,500, and the polythiourethane has repeating units represented by the chemical formula (II); in which formula (II), R is the same as defined above, Y represents a divalent hydrocarbon group, the divalent hydrocarbon group Y may have at least one substituent which does not take part in reaction with the polythiol component, the carbon chain in the hydrocarbon group may include at least one hetero atom, X represents an oxygen or sulfur atom, and n represents an integer of 1 or more.