Abstract: One aspect of the present invention relates to a process for preparing plastic lenses having a high-refractive index comprising forming a mixture containing one or more polyisocyanate compounds; one or more active hydrogen compounds selected from the group consisting of a polyol compound having no sulfur atom, a polyol compound having at least one sulfur atom, and a polythiol compound having at least one sulfur atom in addition to the sulfur atom contained in mercapto group and at least one internal releasing agent and then casting and polymerizing the mixture.

Abstract: A composition for a urethane-base plastic lens, comprising:(a) at least one ester compound selected from the group consisting of isocyanate compounds, isothiocyanate compounds and isocyanato-containing isothiocyanate compounds,(b) at least one active hydrogen compound selected from the group consisting of hydroxyl compounds, mercapto compounds and mercapto-containing hydroxyl compounds,(c) a tertiary amine, and(d) a Lewis acid;a plastic lens obtained by heating and curing the composition, and a process for the production of the plastic lens. The composition has a long pot life and can produce an optically uniform plastic lens in a short time.

Abstract: A composition for optical materials is herein disclosed which comprises the following two components (a) and (b):(a) a component containing at least one of poly isocyanates represented by the formula (1)A.paren open-st.S--B--NCO).sub.n (1)wherein A is an alkanediyl group or an alkanetetrayl group which may contain a sulfur atom, or a dithianetetrayl group, and the alkanediyl group or the alkanetetrayl group may be substituted by a phenyl group; B is a methylene chain represented by .paren open-st.CH.sub.2 .paren close-st..sub.m (m is an integer of 1 to 4) which may contain a sulfur atom, and B's may be the same or different; and n is an integer of 2 or 4, and(b) a component containing at least one of polythiols having two or more mercapto groups. The composition is useful to provide optical products such as plastic lenses, filters, substrates for recording media and optical fibers which have a very high refractive index and which are excellent in heat resistance.

Abstract: One aspect of the present invention relates to a process for preparing plastic lenses having a high-refractive index comprising forming a mixture containing one or more polyisocyanate compounds; one or more active hydrogen compounds selected from the group consisting of a polyol compound having no sulfur atom, a polyol compound having at least one sulfur atom, and a polythiol compound having at least one sulfur atom in addition to the sulfur atom contained in mercapto group and at least one internal releasing agent and then casting and polymerizing the mixture.

Abstract: Described are a high-speed polymerizable resin composition and a lens obtained from it. The composition comprises:a) at least 70 but smaller than 90 parts by weight of a mixture composed of:i) an aromatic polyisocyanate compound represented by the following formula (I): ##STR1## wherein R represents a hydrogen atom or a methyl group, and ii) a polythiol having at least 3 mercapto groups per molecule and a sulfur content of at least 40 wt. %; andb) at least 10 but smaller than 30 parts by weight of a compound which has, in a molecule, at least one functional group selected from a hydroxyl group or a mercapto group and also at least one functional group selected from an acrylic group, methacrylic group or styrylic group, said composition containing isocyanato groups.

Abstract: A polymerizable monomer has the formula, ##STR1## where R.sub.5 and R.sub.6 are similar or dissimilar and are selected from group consisting of hydrogen and methyl, k is an integer of 2-10, and the isopropenyl substituent on the aromatic ring is in the p-position or m-position.The polymerizable monomer can be used to prepare a high hardness transparent resin which in turn can be used to prepare a laminated transparent plastic material.

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 non 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.

Abstract: A laminated transparent plastic material comprises a transparent resin material having a total visible light transmittance of at least 85% and a high hardness transparent resin layer of at least 0.2 mm thick having a pencil hardness of at least 4H, Rockwell M scale hardness of at least 100, and a total visible light transmittance of at least 85% overlying the surface of the transparent resin material, the laminated transparent plastic material having a bending modulus of elasticity of at least 350 kgf/mm.sup.2.A polymerizable monomer has the formula, ##STR1## where R.sub.5 and R.sub.6 are similar or dissimilar and are selected from group consisting of hydrogen and methyl, k is an integer of 2-10, and the isopropenyl substituent on the aromatic ring is in the p-position or m-position.

Abstract: The present invention relates to a polysulfide based resin lens, comprising a mixture of at least one epoxy resin having at least two epoxy groups, and at least one polythiol compound having at least two mercaptan groups, and at least one internal release agent, which is cast polymerized, and the process for preparing the same.

Abstract: In an electronic endoscope apparatus each of the signals of a plurality of systems output from at least one solid state imaging device is judged by a signal monitoring device as to whether it is normal or not. On the basis of the judged result, the processing mode corresponding to each of the signals of the plurality of systems is changed and each signal is processed. If an abnormality occurs, an observed image with which the endoscope inspection can continue will be secured to be safe. Further, in the electronic endoscope apparatus, when the output signal from the solid state imaging device is judged to be abnormal, the amount of illuminating light will be attenuated, the danger by the excessive amount of illuminating light will be avoided and the safety of the person being monitored will be secured.

Abstract: A mercapto compound represented by the following formula (1): ##STR1## is obtained by reacting, in the presence of a mineral acid, thiourea with a compound represented by the following formula (2): ##STR2## wherein X means a hydroxyl group or a chlorine or bromine atom, and then adding a base to alkalinize the reaction mixture so that the reaction product is hydrolyzed.The mercapto compound represented by the formula (1) can be reacted with at least one cyanate compound selected from the group consisting of polyisocyanate compounds, polyisothiocyanate compounds and isocyanate-group-containing isothiocyanate compounds to form a sulfur- containing urethane resin. A lens made of the resin is colorless and transparent, has high refractive index and low dispersion characteristics, and is excellent especially in heat resistance.

Abstract: Herein disclosed are an .alpha.-(aminocyclohexyl)alkylamine represented by the following general formula (II): ##STR1## wherein R represents hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, provided that the amino group bonded to the cyclohexyl group may be in either of the 2-, 3- and 4-positions and a method for preparing it; an .alpha.-(isocyanatocyclohexyl)alkylisocyanate of Formula (II) wherein the amino groups are replaced with isocyanato groups and a method for preparing it; polyisocyanato-isocyanurate represented by the following general formula (IV): ##STR2## wherein R.sub.1, R.sub.2 and R.sub.

Abstract: The present invention discloses a composition for high refractive index plastic lens consisting of a monomer mixture wherein a particular aliphatic thiol compound is added to a polyisocyanate represented by general formula (1): ##STR1## wherein each X represents a hydrogen atom or a methyl group; each R represents a chlorine atom, a bromine atom, a methyl group or an ethyl group; m represents an integer of 0-4; and n represents an integer of 2-4, and a polythiol of formula (2): ##STR2## and a high refractive index plastic lens made of a urethane-containing resin obtained by polymerizing said composition.

Abstract: A mercapto compound represented by the following formula (1): ##STR1## is obtained by reacting, in the presence of a mineral acid, thiourea with a compound represented by the following formula (2): wherein X means a hydroxyl group or a chlorine or bromine atom, and then adding a base to alkalinize the reaction mixture so that the reaction product is hydrolyzed.The mercapto compound represented by the formula (1) can be reacted with at least one cyanate compound selected from the group consisting of polyisocyanate compounds, polyisothiocyanate compounds and isocyanate-group-containing isothiocyanate compounds to form a sulfur-containing urethane resin lens made of the resin is colorless and transparent, has high refractive index and low dispersion characteristics, and is excellent especially in heat resistance.

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 novel polymerizable monomer represented by the formula (I) useful as a raw material for the high surface hardness transparent resin. ##STR1## wherein R is an aliphatic residue having or not having an oxygen atom, an alicyclic ring, a heterocyclic ring or an aromatic ring, or an alicyclic residue, l is 0 or 1, each of i and j is an integer of 1 or more, and when l=0, i=j=1, when l=1, (i+j) is 4 or less, when j=1, X is oxygen or sulfur, when j.gtoreq.2, all X's are oxygen or sulfur, or one X is oxygen and the other X's are sulfur, or one X is sulfur and the other X's are oxygen.The high surface hardness transparent resin comprises a crosslinked polymer prepared by copolymerizing a monomer (A) represented by the formula (I) as above and a monomer (B) containing one or more functional groups of at least one kind selected from the group consisting of CH.sub.2 .dbd.CH--C(O)--O--, CH.sub.2 .dbd.C(CH.sub.

Abstract: A movement amount detected by a movement detection circuit on the basis of an image signal corresponding to an object image is input to a minimum value detection circuit. This detection circuit sets an operation time for the detection of the minimum value by using fuzzy inference on the basis of the movement amount and the gradient amount of the movement. An image signal corresponding to the smallest movement amount in this operation time is retained in a freeze memory. In this case, the operation time is set by fuzzy inference by using the movement amount and the gradient amount as factors for fuzzy inference so that the operation time can be set automatically to a time suitable for obtaining static images possessing a small amount of movement.

Abstract: Herein disclosed are an .alpha.-(aminocyclohexyl)alkylamine represented by the following general formula (II): ##STR1##wherein R represents hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, provided that the amino group bonded to the cyclohexyl group may be in either of the 2-, 3- and 4-positions and a method for preparing it; an .alpha.-(isocyanatocyclohexyl)alkylisocyanate of Formula (II) wherein the amino groups are replaced with isocyanato groups and a method for preparing it; polyisocyanato-isocyanurate represented by the following general formula (IV): ##STR2##wherein R.sub.1, R.sub.2 and R.sub.

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: There is provided a frozen picture memorizing memory holding as a frozen picture image a picture image signal imaged by an electronic endoscope. By the operation of a frozen picture directing switch, whether the frozen picture is adapted to the memorizing condition or not is judged through a picture image movement detecting circuit. In case it is judged to be adapted to the memorizing condition, the picture image signal is memorized actually as a frozen picture image to obtain a clear frozen picture having little color smear and fogging.