The purpose of the present invention is to appropriately control the rate of polymerization of a composition in which a thiol compound and an isocyanate compound are added to an episulfide compound and thereby provide an optical material which has high transparency. This composition for use as optical material comprises (a) an episulfide compound, (b) an isocyanate compound, (c) a thiol compound, and (d) a benzyl halide compound represented by formula (1):

##STR00001##

wherein: X is a halogen; L is selected from the group consisting of a hydrogen atom, a methyl group, a halogen, a mercaptomethyl group, and an isocyanate methyl group; and n is 1 or 2.

A method for producing a polythiol compound, the method including reacting a halide represented by Formula (1) with an alkali metal compound selected from the group made of an alkali metal sulfide and an alkali metal hydroxide to obtain a polyol compound selected from the group made of a polyol compound represented by Formula (2) and a polyol compound represented by Formula (3), in which a content of iron in the alkali metal compound is 100 ppm or less on a mass basis.

##STR00001##

in Formula (1), X represents a halogen atom.

##STR00002##

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

A self-restoring polyurethane-based polymer obtained by polymerization of a composition containing an aromatic disulfide diol represented by Chemical Formula, HOAr.sub.1SSAr.sub.2OH, an alicyclic polyisocyanate, and a polyol. Ar.sub.1 and Ar.sub.2 each are independently a substituted or unsubstituted C.sub.6-C.sub.30 arylene group. The composition satisfies Equation, 0.1M.sub.[disulfide]/M.sub.[OH]. M.sub.[disulfide] is a total mole number of the aromatic disulfide diol in the composition, and M.sub.[OH] is a total mole number of the aromatic disulfide diol and the polyol in the composition.

A polymerizable composition for an optical material according to the present invention includes (A) phosphite triester represented by Formula (1), (D) a photochromic compound, (E) a polyisocyanate compound, and (F) a difunctional or higher functional active hydrogen compound.

##STR00001##

This invention provides flame retardant compositions comprised of or formed from components comprising a sulfur-containing compound and at least one isocyanate-reactive brominated flame retardant.

The present invention is a polishing pad formed by foamed polyurethane, with a content of S phase in the foamed polyurethane, as determined by pulsed NMR measurement at 25 C., exceeding 70%.

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.