Abstract: Disclosed is a radiation-crosslinkable thermoplastic polyurethane composition comprising (a) the reaction product of: (i) an aliphatic polyisocyanate, and (ii) a polyahl, and (b) a reactive monomer cross-linker. The reactive monomer cross-linker facilitates cross-linking of the reaction product upon contact of the cross-linker-containing composition with photons from a radiation source. Also disclosed is a process for converting this thermoplastic polyurethane into a thermoset polyurethane by irradiating the thermoplastic polyurethane with a beam of photons.

Abstract: A new UV curable pressure sensitive adhesive composition, which comprises in weight percent: about 0.1% to about 15% of a photoinitiator agent, about 10% to about 80% of a polyurethane resin with a pendent acrylate functionality, zero to about 70% by of an acrylate monomer, about 0.1% to about 25% by weight of a 1,2-vinyl polybutadiene component, and zero to about 50% by weight of a tackifier agent.

Abstract: Compounds of the formulaRG--A--INwherein IN is a photoinitiator basic structure A is a spacer group and RG is a functional reactive group can be employed as coreactive photoinitiators for photo-polymerization of systems containing ethylenically unsaturated compounds.

Abstract: A liquid curable resin composition for optical fibers comprising a polymer (a) having a number average molecular weight of 5,000 or more and derived from at least two types of recurring ethylenic units, of which one type has a substituent group containing an ethylenically unsaturated group and the second type is substituted by a group --COOR.sup.3 (wherein R.sup.3 is a hydrogen atom or a hydrocarbon group having 1-30 carbon atoms), an aryl group, a cyano group, an alkyl group having 1-10 carbon atoms or by one or more halogen atoms.

Abstract: A photopolymerizable composition for a photosensitive lithographic printing plate, comprising (A) addition-polymerizable ethylenically unsaturated bond-containing monomers, (B) a photopolymerization initiator system and (C) a polymer binder having carboxyl groups in its molecule, wherein the addition-polymerizable ethylenically unsaturated bond-containing monomers (A) contain a specific monomer which is a phosphoric acid ester compound (A-1) having at least one (meth)acryloyl group and/or a compound (A-2) of the following formula ##STR1## wherein R.sup.1 is a hydrogen atom or a methyl group, X is a C.sub.1-6 alkylene group which may be branched and may be substituted by halogen, and m is an integer of at least 2, and the polymer binder (C) having carboxyl groups in its molecule, is a compound having at least a part of the carboxyl groups reacted with an alicyclic epoxy group-containing unsaturated compound.

Abstract: A photosensitive resin composition comprising the following components (A), (B) and (C): (A) a photopolymerizable urethane (meth)acrylate compound containing at least two acryloyl or methacryloyl groups, (B) an alkali-soluble polymer compound having an acid value of from 50 to 250 mgKOH/g, and (C) a photopolymerization initiator, wherein the photosensitive resin composition has an electrical insulation resistance of 8.0.times.10.sup.9 to 1.0.times.1.0.sup.14 .OMEGA..multidot.cm after photocuring. A photosensitive resin laminated film comprising a flexible film, a photosensitive layer provided on the flexible film, and a releasable film layer provided on the photosensitive layer, wherein the photosensitive layer comprises the above photosensitive resin composition.

Abstract: Disclosed is a photosensitive resin composition suitable as a resist material against sandblasting for pattern-wise engraving of the surface of a body after photo-lithographic patterning, which comprises: (a) a urethane compound having a (meth)acrylate group at the molecular end, which is obtained from a polyether or polyester compound having a hydroxy group at the molecular chain end, a diisocyanate compound and a (meth)acrylate compound having a hydroxy group; (b) an alkali-soluble polymeric compound having an acid value in the range from 50 to 250 mg KOH/g; and (c) a photopolymerization initiator.

Abstract: A new UV curable pressure sensitive adhesive composition, which comprises in weight percent: about 0.1% to about 15% of a photoinitiator agent, about 10% to about 80% of a polyurethane resin with a pendent acrylate functionality, zero to about 70% by of an acrylate monomer, about 0.1% to about 25% by weight of a an acrylated polybutadiene component, and zero to about 50% by weight of a tackifier agent.

Abstract: A photosensitive resin composition comprising (A) a binder polymer having carboxyl groups, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, and (C) a photoinitiator can provide a film excellent in mechanical strength, chemical resistance, flexibility, and suitable for producing a photosensitive element.

Abstract: An unsaturated group-containing urethane compound of the following formula (I): ##STR1## wherein X is a C.sub.1-20 alkylene group which may be branched, and R.sup.1 is a group of the following structural formula (A) or (B): ##STR2## wherein each of R.sup.2 and R.sup.3 which are independent of each other, is a hydrogen atom or a methyl group, and Y is a C.sub.1-6 alkylene group which may be branched.

Abstract: A radiation-curable coating composition comprising a PVC resin, an acrylic or methacrylic compound and a radiation-reactive urethane oligomer. Also described is a process for coating a material, comprising the steps of applying to the material a coating composition according to the invention, heating to heart-cure the coating composition and irradiating the composition to radiation-cure the coating composition. There is also provided an article comprising a material coated with the composition according to the invention. The invention is particularly useful for coating resilient vinyl flooring materials.

Abstract: A printing ink for the printing of security documents by the method of engraved steel die printing, having a viscosity of at least 1 Pa.multidot.s at 40.degree. C. under a shear of about 1000 sec.sup.-1, containing a binder matrix, a polymerization initiator for polymerizable matrix components, fillers and pigments, and the usual additives. The binder matrix contains at least one cationically polymerizable compound, modified to bring about the desired rheology of the ink, and the photoinitiator, activable by UV, heat and EB, is an onium salt capable of releasing a Lewis or Bronsted acid.This ink has best and very rapid drying characteristics.

Abstract: A process is disclosed for producing a liquid jet recording head comprising applying an active energy-curing resin composition onto at least a part of a surface of a first member for forming a wall of the liquid path; exposing the applied active energy-ray-curing resin to an active energy ray selected from the group consisting of an ultraviolet-ray having an intensity of 1 mW/cm.sup.2 to 100 mW/cm.sup.2 and an electron beam having an intensity of 0.5M Rad to 20M Rad; and providing a second member on the exposed active energy-ray-curing resin composition.

Abstract: A process is disclosed for producing a liquid jet recording head comprising applying an active energy-curing resin composition onto at least a part of a surface of a first member for forming a wall of the liquid path; exposing the applied active energy-ray-curing resin to an active energy ray selected from the group consisting of an ultraviolet-ray having an intensity of 1 mW/cm.sup.2 to 100 mW/cm.sup.2 and an electron beam having an intensity of 0.5M Rad to 20M Rad; and providing a second member on the exposed active energy-ray-curing resin composition.

Abstract: A process is disclosed for producing a liquid jet recording head comprising applying an active energy-curing resin composition onto at least a part of a surface of a first member for forming a wall of the liquid path; exposing the applied active energy-ray-curing resin to an active energy ray selected from the group consisting of an ultraviolet-ray having an intensity of 1 mW/cm.sup.2 to 100 mW/cm.sup.2 and an electron beam having an intensity of 0.5M Rad to 20M Rad; and providing a second member on the exposed active energy-ray-curing resin composition.

Abstract: A liquid composition which on exposure to actinic radiation polymerizes to form a heat-curable solid film adhesive, said composition comprising (A) a heat-curable phenol-aldehyde resol resin, (B) a photopolymerizable polyurethane or polyester having, on average, more than one polymerizable acrylic group per molecule, or a mixture of said polyurethane and said polyester, (C) a photopolymerization initiator for (B) and (D) a polyvinylacetal.

Abstract: A method for modifying the surface of a solid polymer wherein the polymer surface is exposed to an aqueous solution containing a two-ring heterocyclic compound that is described in more detail herein. The polymer and the two-ring heterocyclic compound are irradiated with electromagnetic radiation having a wavelength ranging from about 10 nm to about 400 nm to photochemically immobilize the two-ring heterocyclic compound to the polymer.

Abstract: A photocurable composition useful in preparing water-developable, solid printing plates is prepared by blending a urethane (meth)acrylate prepolymer with a complexing polymer based on poly(vinyl pyrrolidone) composition. The resulting composition is suitably formulated with additional photoactive (meth)acrylate monomers or oligomers and photoinitiator for casting or extrusion on a substrate to form a flexographic printing plate. Following UV exposure of the plate through a negative, unexposed areas can be removed by washing with aqueous media, to give a plate with a desirable relief image. The use of the aqueous washout solution as opposed to organic solvents minimizes pollution problems. The use of the complexing polymer significantly reduces the cold flow of the uncured plate and both increases toughness and reduces tack of the cured plate.

Abstract: An actinic radiation-reactive pressure-sensitive adhesive composition which can be cured in air at a high speed, without irritation and bad smell, comprises1 a pressure-sensitive adhesive compound comprising an acrylate copolymer and2 an actinic radiation-curable resin comprising (1) one or more polythiol compounds and (2) one or more polyene compounds each having an least two actinic radiation-reactive acrylate carbon-to-carbon double bonds in the molecule.

Abstract: There is provided a radiation-curable adhesive tape comprising a radiation-curable adhesive layer which is formed on a radiation transmitting-substrate. The radiation-curable adhesive layer is composed of an acrylic adhesive and radiation-curable compound having carbon-carbon double bonds. The radiation-curable tape can be used preferably in processing steps for the production of semiconductor wafer, ceramics and glass employing a direct picking-up system.

Abstract: An actinic radiation-reactive pressure-sensitive adhesive composition can be cured in air at a high speed, without irritation and bad smell, and comprises1 a pressure-sensitive adhesive organic compound, and2 an actinic radiation-curable resin comprising (1) one or more polythiol compounds and (2) one or more polyene compounds each having at least two actinic radiation-reactive carbon-to-carbon double bonds in the molecule.

Abstract: A light-polymerizable resin composition for the preparation of clasp patterns comprises (a) a light-polymerizable compound having at least one ethylenically unsaturated double bond, (b) an organic filler material, (c) a light polymerization initiator and (d) a reducing agent. The light-polymerizable compound is solid at normal temperature, and may be a mono- or polyfunctional acrylate or methacrylate.

Abstract: A photopolymerizable mixture is disclosed that contains a polymer binder, a polymerizable compound having at least one terminal ethylene double bond and a boiling point above 100.degree. C. at normal pressure, a hexaarylbisimidazole and a 1,3-diarylpyrazoline or a 1-aryl-3-aralkenyl-pyrazoline. The mixture is suitable for the preparation of printing plates and photoresists and is distinguished by high photosensitivity and low sensitivity towards acid solutions.

Abstract: This invention provides hardenable compositions useful as construction media for a wide range of applications. Particular utility is found in the dental and medical arts where such compositions are highly suitable for the formation and construction of denture base, denture baseplates, denture liners, denture repair, custom trays, veneering for crowns and bridgework, artificial teeth, veneers and repair for natural teeth, and tooth restorative fillings. Such materials having improved impact strengths and elastic moduli when hardened are disclosed which include rubber-modified polymer.

Abstract: The disclosed photosensitive flexographic printing plate composition is to impart a soft printing plate by rubber compounding photosensitive resin which comprises(A) 5-50 wt % of a photopolymerizable prepolymer consisting essentially of a component having the general formula ##STR1## where, R is an alkylene group or polyoxyalkylene group having 2-8 carbons, R.sub.1 is an H or CH.sub.3 group, R.sub.2 and R.sub.3 are diisocyanate residues, R.sub.4 is a portion excluding a hydroxyl group of dienic liquid rubber having a hydroxyl group of dihydric alcohol having less than 2000 molecular weight of the general formula ##STR2## where, R.sub.5 is an alkylene group having 2-8 carbons, R.sub.6 and R.sub.7 are an H, CH.sub.

Abstract: A hot melt adhesive crosslinkable by UV irradiation comprising a hot melt adhesive base, a saturated hydrocarbon oligomer containing at least one acryloyl group in a molecule for affording crosslinkability by UV irradiation, and a photopolymerization initiator, an optical disc comprising a pair of substrate, at least one of which is provided with an information recording layer, adhered to each other by means of a hot melt adhesive crosslinkable by UV irradiation and the process for preparing the same are disclosed. The adhesive of the present invention has a high heat resistance and heat stability, is applicable at a low temperature and at a low viscosity, has high softening point and high viscosity by UV irradiation. The optical disc of the present invention has high productivity, no corrosion and high heat resistance.

Abstract: Ultravioletsetting resin composition contains fragmentary quartz glass powder in the ratio of 50 to 200 parts to 100 parts of the ultravioletsetting resin. The surface hardness of the ultravioletsetting resin of the present invention is increased in a short time by the application of ultraviolet rays.

Abstract: A resin composition for forming a durable protection coating contains (A) an alkali-soluble resin which is a polymer of a conjugated diene and has a monoamidated succinic acid group represented by the following formula (I) of: ##STR1## wherein R.sup.1 and R.sup.2 each stand for a hydrogen atom, a halogen atom or an organic residue having 1 to 3 carbon atoms; and R.sup.3 stands for an organic residue having 1 to 16 carbon atoms; (B) a pre-polymer having a photosensitive ethylenic double bond; and (C) a photopolymerization initiator. The mixing ratio by weight of the alkali-soluble resin (A) to the pre-polymer (B) ranges from 1:4 to 4:1. A process for preparing the durable protection coating contains applying the resin composition on a substrate, and exposing the resin composition to ultraviolet ray through a circuit pattern mask to cure the resin composition followed by development and after-curing to form the protection coating.

Abstract: A UV sensitive coating composition is described which uses a polymer prepared from a condensation reaction of a diisocyanate, a hydroxy alkyl (di or tri) (meth)acrylate and a carboxylic acid polyol. Optionally, a polyol and/or a dicarboxylic acid polyol can also be included as reactants. The coating polymer, thus prepared, is combined with binders and crosslinkers to form a solder mask.

Abstract: An actinic radiation-curable, rust-preventive coating composition suitable for use in temporary protection of steel products from rusting and having improved rust preventing property even in the presence of oil on the steel surface is disclosed. The coating composition comprises: (A) from 10 to 50 parts by weight of a vinyl polymer having a glass transition temperature of not lower than 5.degree. C. and a solubility parameter in the range of 9 to 11.5; (B) from 50 to 90 parts by weight of one or more polymerizable compounds having at least one unsaturated group capable of initiating reaction by actinic radiation; and (C) from 0.1 to 20 parts by weight of an organic phosphate of the formula: ##STR1## wherein R.sub.1 is hydrogen or methyl; Y is a straight or branched chain alkylene having 2 to 20 carbon atoms which may be interrupted by one or more ester or oxy linkages and/or aromatic rings; and n is an integer of 1 to 3.

Abstract: An improved active energy ray-curing resin composition comprising (i) a graft copolymerized polymer having a number average molecular weight of 5,000 or more and a weight average molecular weight of 50,000 or less: (ii) a linear polymer having a number average molecular weight of 5,000 or more and a weight average molecular weight of 350,000 or less and having a glass transition temperature of 60.degree. C. or more: (iii) an esterified polyurethane obtained from oligoesterdiol or from oligoesterdiol and dihydric isocyanate which has a molecular chain terminal end being esterificated with acrylic acid: and (iv) a photopolymerization initiator.The resin composition can be desirably cured with an active energy ray such as ultraviolet ray or electron beam and it is capable of being laminated in a desired pattern on a copper-coated laminate for use as a printed board or on a plate of metal, glass, ceramics or plastic.

Abstract: A dental glass ionomer cement composition comprises:(a) 5 to 100 parts by weight of a polymer of an .alpha.-.beta. unsaturated carboxylic acid having a weight average molecular weight of 5,000 to 40,000,(b) 5 to 100 parts by weight of a fluoroaluminosilicate glass powder having an average particle size of 0.02 to 10 .mu.m and a specific gravity of 2.4 to 4.0 and capable of reacting with said "polymer of an .alpha.-.beta. unsaturated carboxylic acid having a weight average molecular weight of 5,000 to 40,000",(c) 5 to 100 parts by weight of a polymerizable unsaturated organic compound having at least one CH.sub.2 .dbd.C(R1)--COO--group wherein R1=H or CH.sub.3,(d) 0.01 to 5 parts by weight of a polymerization catalyst,(e) 2 to 50 parts by weight of water,(f) 0.01 to 20 parts by weight of a surface active agent, and(g) 0.01 to 5 parts by weight of a reducing agent, and optionally h. 0 to 50 parts by weight of an inorganic filler having an average particle size of 0.02 to 10 .mu.

Abstract: An active energy ray-curing resin composition comprises (i) a heat-crosslinkable linear copolymer comprising 5 to 30 mol % of a monomer represented by the general formula I shown below and 5 to 50 mol % of a monomer represented by the general formula II shown below as the copolymer constituents: ##STR1## (wherein R.sup.1 is hydrogen or alkyl or hydroxyalkyl group having 1 to 3 carbon atoms; R.sup.2 is hydrogen or alkyl or acyl group having 1 to 4 carbon atoms which may have a hydroxyl group; R.sup.3 is hydrogen or alkyl group having 1 to 3 carbon atoms; R.sup.4 is a divalent hydrocarbon group which may have internally an ether bond and may also be substituted with halogen atoms; and R.sup.5 is alkyl having 3 to 12 carbon atoms or phenylalkyl group or phenyl group), and (ii) a monomer having an ethylenically unsaturated bond.

Abstract: Water-processable screenprinting stencils and resists are based upon photopolymerizable systems in which the hydrogen donor compound is a modified polyvinylalcohol having pendant dialkylamino groups.

Abstract: The invention provides a radiation-curable liquid resin for use as a secondary coating of lightwave guides which is a reaction product of (meth)acrylic acid or -acid chloride or isocyanatoalkyl-(meth)acrylate with a 1:2 addition compound of a diepoxide with a mean molecular weight.ltoreq.1000 and a short-chain .alpha.,.omega. -diol with a mean molecular weight.ltoreq.700 or with a 1:2 addition compound of a diepoxide with a mean molecular weight.ltoreq.400 and a monovalent aliphatic alcohol with a mean molecular weight.ltoreq.200, where the diepoxide is an aliphatic-aromatic or aromatic diglycidylether, an aliphatic or cycloaliphatic diepoxide or a silicon-organodiepoxide, and where the short-chain .alpha.,.omega. -diol is an .alpha..omega. -hydroxy-terminated polyoxyalkylene, an .alpha.,.omega. -hydroxy-terminated polyester, an .alpha.,.omega. -hydroxy-terminated polybutadiene, an .alpha.,.omega. -hydroxyterminated organo-functional polysiloxane or an .alpha.,.omega. -alkanediol with a mean molecular weight.

Abstract: The present invention relates to a light-sensitive resin composition that has resistance to heat and chemicals, is particularly adapted for use in the formation of a protective film for chemical plating and which is also improved in resistance to the heat of soldering. This light-sensitive resin composition contains (a) a polyurethane (meth)acrylate, (aa) a bisphenol type epoxy (meth)acrylate, (b) a linear high-molecular weight compound, and (c) a polymerization initiator which generates free radicals upon exposure to light. This resin composition is applicable to the manufacture of printed circuit boards by the additive process.

Abstract: Radiation curable coating compositions for providing solvent-resistant abhesive coatings comprise polyfluorinated acrylates and methacrylates, polyethylenically unsaturated crosslinking agents and a film-forming organic polymer. The compositions can be used after radiation curing to render substrates oil, soil, and water repellent. The cured compositions have particular use as release coatings in image transfer systems wherein a fused xerographic image is transferred from the release coated surface, to another surface due to the particular characteristics of the coatings. Novel poly(fluorooxyalkylene)urethane acrylate compounds are also disclosed.

Abstract: A photopolymerizable mixture is disclosed comprising:(a) a polymeric binder,(b) an acrylate or alkacrylate of a polyhydric alcohol containing one or more groups which are photooxidizable on exposure in the presence of the photoreducible dye, and one or more urethane groups,(c) a photoreducible dye as photoinitiator,(d) a trihalomethyl compound which can be cleaved by irradiation, and(e) an acridine or phenazine compound which is active as a photoinitiator.The mixture is suitable for the production of printing plates and photoresists and is distinguished by increased photosensitivity.

Abstract: A radiation curable liquid resin composition comprising a radiation curable liquid base resin and polymer microparticles having an average particle size from 0.01 to 0.6 microns. The incorporation of polymer microparticles to the base resin may improve the rheological property of the liquid composition and also the physical properties of cured film therefrom.

Abstract: A crude drug ingredient having bactericidal activity incorporated into a curable composition comprising a (meth)acrylate type monomer, a polymerization initiator and if necessary a filler to formulate the ingredient into the drug having sustained release property. The curable composition containing the crude drug ingredient is applied to a defective part of a tooth or an artificial gum for preventing dental diseases such as carious tooth, pyorrhea alveolaris, and the like.

Abstract: Described herein are compositions suitable for photocopolymerization comprising a cyclic vinyl ether containing compound and urethane acrylates. Photocurable coatings can be prepared from such composition and such coatings have markedly improved flexibility and impact resistant properties.

Abstract: Disclosed herein is a photopolymerizable composition containing at least (A) a high-molecular compound with a weight-average molecular weight of not less than 10,000 having a polymerizable double bond in the side chain, and (B) a polymerizable monomer represented by the following formula (I): ##STR1## (wherein R.sup.1, R.sup.2 and R.sup.3 represent hydrogen atom, ##STR2## and two or more of them are not hydrogen atom at the same time).

Abstract: Vehicles for ultraviolet radiation-curable ceramic enamels comprising (a) acrylate- or methacrylate- modified oligomers; (b) monofunctional acrylate- or methacrylate-modified monomers; (c) pentafunctional acrylate or methacrylate-modified monomers; and (d) a photoinitiator system for said polymerizable components; and the enamels prepared therefrom comprising glass enamels and the vehicles as described.

Abstract: This invention provides hardenable compositions useful as construction media for a wide range of applications. Particular utility is found in the dental and medical arts where such compositions are highly suitable for the formation and construction of denture base, denture baseplates, denture liners, denture repair, custom trays, veneering for crowns and bridgework, artificial teeth, veneers and repair for natural teeth, and tooth restorative fillings. Such materials having improved impact strengths and elastic moduli when hardened are disclosed which include rubber-modified polymer.

Abstract: Disclosed herein are novel diesters of (meth)acrylic acid represented by the following formula: ##STR1## wherein the mean values of m and n are respectively 0 to 5, preferably 0 to 3, the mean value of m+n is 1 to 10, preferably 1 to 6, and R represents H or CH.sub.3.Also, disclosed herein are resin compositions comprising said diester(s) of (meth)acrylic acid, polyurethane (meth)acrylate(s), monoethylenically unsaturated monomer(s) and initiator(s) of photopolymerization as an optional component.

Abstract: An active energy beam-curable type resin composition, which comprises (A) a graft copolymer comprising a main chain composed mainly of structural units of monomers containing one (meth)acryloyl group and a dicyclopentenyl derivative group represented by the following general formula (I): ##STR1## wherein Z represents a five-membered ring given by ##STR2## and R.sub.1 and R.sub.

Abstract: An active energy ray-curable resin composition comprises (A) a graft copolymerized polymer comprising graft chains composed mainly of structural units derived from at least one monomer selected from the group consisting of (a) hydroxyl containing (meth)acrylic monomers, (b) amino or alkylamino containing (meth)acrylic monomers, (c) carboxyl containing (meth)acrylic or vinyl monomers, (d) N-vinylpyrrolidone, (e) vinylpyridine or its derivatives and (f) (meth)acrylic amide derivatives represented by the general formula (II) shown below: ##STR1## (wherein R.sub.1 is hydrogen or methyl group and R.sub.2 is hydrogen or an alkyl or acyl group having 1 to 4 carbon atoms which may have hydroxyl group added to trunk chains composed mainly of structural units compsiting at least one monomer selected from the group consisting of the monomer represented by the general formula (I) shown below: ##STR2## (wherein R.sub.1 to R.sub.

Abstract: A combined chemical-light-polymerization type composition for dental restoration consists of a formulation A composed mainly of a. an ethylenically polymerizable unsaturated compound, b. a photopolymerization initiator and c. a reducing agent, and a formulation B composed mainly of d. a filler and e. an organic perioxide. The formulations A and B are separately packaged and designed to be mixed for use.

Abstract: A method of molding high definition skins of a photocurable polymers, to said skins and said skin filled with a foam to yield a cushion protective or decorative item.

Abstract: Upon imagewise exposure, a photopolymerizable composition which contains(a) a polymeric binder;(b) a compound that has at least one terminal ethylenic double bond and a boiling temperature, at standard pressure, of above 100.degree. C., and that can form a polymer by polymerization initiated by a free-radical process;(c) a photoinitiator;(d) a leuco base of a triarylmethane dye; and(e) a photochromic spiro-indolino-benzopyran compound represented by the formula ##STR1## wherein R denotes a hydrogen atom or a C.sub.1 -to-C.sub.16 alkyl group,R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different, and each denotes a hydrogen or a halogen atom, a C.sub.1 -to-C.sub.4 alkyl or alkoxy group, or a nitro group, andR.sup.5, R.sup.6, R.sup.7 and R.sup.8 are identical or different, and each denotes a hydrogen or a halogen atom, a nitro or an amino group, a C.sub.1 -to-C.sub.5 alkyl or alkoxy group, or a C.sub.6 -to-C.sub.