| 摘要 |
Polymerization catalysts are described for organic polythiourethane glass which do not contain organometallic compounds, and consisting of a mixture of a tertiary aliphatic amine and a disubstituted phosphoric acid in a molar ratio ranging from 1/1.3 to 1/20. Polymerizable liquid compositions of the polythiourethane type are also described, essentially consisting of three components (A), (B) and (C), wherein component (A) contains at least one cycloaliphatic diisocyanate monomer wherein the weight percentage of free isocyanate groups in said component (A) ranges from about 20% to about 50% by weight, preferably from about 25% to about 40% by weight, with respect to the total weight of component (A); component (B) contains at least one polythiol having a molecular weight ranging from 50 to 1,200 g/moles, preferably from 100 to 1000 g/moles, and a functionality ranging from 2 to 5, preferably from 2 to 4, said components (A) and (B) being present in a weight ratio varying from 0.5:1 to 2:1; component (C) being said polymerization catalyst.The process is also described for the production of organic glass starting from said polymerizable liquid compositions of the polythiourethane type. |
