Abstract: The present invention relates to a process for preparing a hard transparent resin comprising polymerizing a monomer (A) having both a functional group of the following formula (I): ##STR1## wherein X is selected from the group consisting of an oxygen atom and a sulfur atom,and a functional group selected from the group consisting of a functional group of the formula (II):CH.sub.2 CR--COO-- (II)wherein R is selected from the group consisting of hydrogen and methyl group,and a functional group of the formula (III): ##STR2## The invention also provides a process for preparing a transparent resin comprising copolymerizing monomer (A) with a monomer (B) having at least one functional group selected from the group consisting ofCH.sub.2 .dbd.CHCOO--,CH.sub.2 .dbd.C(CH.sub.3)--COO--, and ##STR3## This resin can be suitably used as a glazing material, and in the manufacture of optical lenses, optical information recording medium substrates, etc.

Abstract: The present invention relates to a mercapto compound, a process for preparing the mercapto compound, a process for preparing a polythiourethane base resin containing the mercapto compound, and a process for preparing plastic lenses containing the resin.

Abstract: The present invention relates to a high surface hardness transparent resin having excellent scratch resistance, heat resistance and chemical resistance, a glazing material, a protective cover for display devices, an optical lens and a hard coat material comprising the aforesaid resin, and a novel polymerizable monomer which is useful as a raw material of the above-mentioned resin.The monomer is represented by the formula (I) ##STR1## (wherein R is an aliphatic residue having or not having an halogen atom, an oxygen atom, an alicyclic ring, a heterocyclic ring or an aromatic ring, an alicyclic residue, or a heterocyclic residue, n is an integer of 1 to 4, when n=1, X is oxygen or sulfur, when n.gtoreq.2, X's are all oxygen or all sulfur, one X is oxygen while the other X or X's are sulfur, one X is sulfur while the other X or X's are oxygen, or two X's are oxygen while the other X's are sulfur).

Abstract: A resin for urethane lenses is here disclosed which is obtained by reacting an alicyclic isocyanate compound represented by the formula (I) ##STR1## and/or an alicyclic isocyanate compound represented by the formula (II) ##STR2## with at least one active hydrogen compound selected from the group consisting of polyol compounds, polythiol compounds except 1,2-bis[(2-mercaptoethyl)thio]-3-mercaptopropane, and thiol compounds having a hydroxyl group. In addition, lenses comprising this resin and processes for the preparation of the resin and the lenses are also disclosed herein.

Abstract: The present invention relates to resin useful in preparing plastic lenses having a high refractive index comprising reacting an aliphatic polyisocyanate compounds having at least one sulfur atom with one or more of active hydrogen compounds selected from the group consisting of a polyol, a polythiol having sulfur atoms only in a mercapto groups, and a polythiol having at least one sulfur atom other than in the mercapto groups; lenses containing the above-mentioned resin; and a method for the preparation thereof characterized by adding an internal release agent to the mixture of the above-mentioned raw materials in casting lenses from the resin; and lenses obtained by this method.

Abstract: A process for producing a plastic lens having a high refractive index and profile regularity which includes forming a mixture of one or more of sulfur-containing aromatic polyisocyanate compounds, one or more of active hydrogen compounds selected from the group consisting of polyol compounds and polythiol compounds, and at least one internal mold releasing agent. Then subjecting the resulting mixture to casting polymerization, to form the plastic lens.

Abstract: Polyfunctional monomers are disclosed that yield transparent resins having high transparency and excellent surface hardness and heat resistance. The present polyfunctional monomers are represented by the general formula (I): ##STR1## wherein R represents a group having a carbamido group or an oxazolidone group that will be bonded to the dimethylbenzyl group of the formula (I) and an acryl group or methacryl group at the other end. Control of the polymerization of the polyfunctional monomers is easy, and polymerization of the polyfunctional monomers yield and resins having excellent surface hardness, heat resistance, and workability, and having high transparency. The resins are well adapted for use as glazing materials, optical lenses, and optical disc substrates.

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.

Abstract: Polyurethane base lens resins obtained by reacting one or more of sulfur-containing polyisocyanates compound with one or more of sulfur-containing polyols, and polyurethane base lenses comprising these resins are disclosed.A method for preparing polyurethane base lenses which comprises adding internal mold releasing agents to the mixture of the above polyisocyanates and polyols prior to casting polymerization is also disclosed.

Abstract: Disclosed herein is a colorless transparent plastic lens having high refractivity and low dispersion. The lens is light, has heat resistance sufficient for post processing, and is excellent in grinding machinability and impact resistance. It is made of a sulfur-containing urethane resin, which is a polymer of a specific polythiol and a particular polyisocyanate of at least bifunctionality.

Abstract: Disclosed herein are a high-refractivity plastic lens resin obtained by polymerizing under heat at least one polyisocyanate (I): ##STR1## wherein X means a hydrogen, chlorine or bromine atom or a methyl or ethyl group, Z is a hydrogen atom or a methyl group, a stands for an integer of 1-4, b is an integer of 2-4, and a+b is not greater than 6 (a+b.ltoreq.6), with at least one polythiol (II): ##STR2## wherein R means a methyl, ethyl, chloromethyl or bromomethyl group, m stands for an integer of 0-2 and n is 4-m and/or at least one polythiol (III): ##STR3## wherein X means a hydrogen, chlorine or bromine atom or a methyl or ethyl group, Y denotes an oxygen or sulfur atom, r stands for 0 or 1, s is an integer of 0-2, p is an integer of 2-4, q is an integer of 1-4 and p+q is not greater than 6 (p+q.ltoreq.6), in such amounts that the --NCO/--SH molar ratio falls within 0.5-3.0, as well as a lens made of the above resin.

Abstract: Disclosed herein are a resin for high-refractivity lenses, formed by copolymerizing at least one carbonate compound represented by the general formula (I): ##STR1## wherein X is a hydrogen, chlorine or bromine atom, and R is a hydrogen atom or a methyl group with at least one unifunctional monomer represented by the general formula (II): ##STR2## wherein R' is a hydrogen atom or a methyl group and Y represents ##STR3## wherein X' is a chlorine or bromine atom, q is an integer of 0-5, and r is 0 or 1 as well as high-refractivity lenses made of such a resin.The lens-making resin according to this invention has a high refractive index, is excellent in processability such as grinding processability, thermal resistance, solvent resistance and impact resistance. Moreover, it features outstanding miscibility between the unifunctional monomer and the carbonate upon copolymerization thereof, and minimized polymerization strain.