S-alkyl thiocarbamate base resin, plastic lens comprising the resin, and process for making the lens
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsTeruyuki Nagata, Koju Okazaki, Nobuyuki Kajimoto, Tohru Miura, Yoshinobu Kanemura, Katsuyoshi Sasagawa
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Abstract
Disclosed herein are a novel and highly refractive S-alkyl thiocarbamate base resin useful in preparing lenses and a process for producing the resin comprising reacting one or more of polyisocyanate compounds and one or more of mercapto compound having at least one hydroxyl group, a plastic lens made of the resin, and a process for making a plastic lens of high profile regularity from the resin by using internal mold releasing agents in the casting polymerization process.
Claims24
A process for producing an S-alkyl thiocarbamate base resin comprising reacting at least one polyisocyanate compound with at least one hydroxyl containing mercapto compound wherein the mole ratio of said polyisocyanate compound to said hydroxyl containing mercapto compound is from about 0.5 to about 3.0 moles of functional isocyanate groups per mole of functional (SH +OH) group, except for the combination of polyisocyanate compounds having no sulfur atoms and hydroxyl-containing-mercapto compounds having no sulfur atoms other than the mercapto group.
A process for producing an S-alkyl thiocarbamate base lens comprising adding an internal mold releasing agent to a mixture of at least one polyisocyanate compound and at least one hydroxyl containing mercapto compound, and then cast polymerizing the same wherein the mole ratio of said polyisocyanate compound to said hydroxyl containing mercapto compound is from about 0.5 to about 3.0 moles of functional isocyanate groups per mole of functional SH +OH) group.
Dependencies are inferred from the claim text.