ACTIVE ENERGY RAY-CURABLE RESIN COMPOSITIONS, A CURED ARTICLE AND AN OPTICAL LENS OBTAINED THEREFROM, AND NOVEL (METH)ACRYLATE COMPOUNDS THEREFOR

Abstract: Disclosed are active energy ray-curable resin compositions and new (meth)acrylates. The active energy ray-curable resin compositions are excellent in stability of the composition, curability, and coating ability compared to conventional active energy-curable resin compositions. Cured articles prepared from the active energy ray-curable resin compositions have a high refractive index, an excellent scratch resistance, and a moderate flexibility for giving an excellent recovery property in a dent generated by compression, which can be preferably employed as an optical lens such as a Fresnel lens or lenticular lens.

Description: ACTIVE ENERGY RAY-CURABLE RESIN COMPOSITIONS, A CURED ARTICLE AND AN OPTICAL LENS OBTAINED THEREFROM, AND NOVEL (METH)ACRYLATE COMPOUNDS THEREFOR. The present invention relates to active energy ray-curable resin compositions which can be cured by an active energy ray such as an ultraviolet ray or electron beam and, further the present invention relates to a cured article therefrom having a high refractive index, a Fresnel lens or lenticular lens wherein a thermoplastic resin plate is combined with a layer of the cured article, and a transmission type screen in which a thermoplastic resin is combined with two-layers of the cured article. The active energy ray-curable resin compositions are excellent in workability for forming, in properties of a coating layer, and from an economical viewpoint. The active energy ray-curable resin compositions can provide a cured article having a high refractive index, and an optical lens wherein a thermoplastic resin is combined with two-layers of the cured article. The invention also relates to novel (meth)acrylates usable in some of these compositions. An active energy ray-curable resin composition which can be cured by irradiation of an active energy ray such as ultraviolet ray or electron beam has been widely used in a variety of fields such as printing fields, coatings fields, and electric fields, etc., because of its excellent productivity and low pollution from a viewpoint of recent environmental problems. In a general way, active energy ray-curable resin compositions have advantageous properties which are (1) a solvent free and low pollution type, (2) capability of high speed curability and high productivity of products, (3) capability of slight shrinkage in volume because of curing by solid of 100%, and (4) capability of slight thermal loss and minor adverse thermal affection to base materials, etc. As more specific uses of the active energy ray-curable resin compositions, there may be cited resin for inks, coating for plastics, coating for films, coating for metals, coating for furniture, lining materials, adhesives, insulating varnishes for electronics, insulating sheet, laminated sheet, printed circuit board, resist ink, and encapsulating materials for semiconductors. In addition to these uses, the active energy ray-curable resin compositions have been employed as resins for moulding and as a cured article having a high refractive index, such as coatings for an optical lens, particularly, a Fresnel lens or a lenticular lens, and a transmission type screen in which a Fresnel lens is combined with a lenticular lens, owing to the above-described advantageous properties. A Fresnel lens or a lenticular lens requires thin thickness, and further a high refractive index, for example, more than 1.47, preferably more than 1.50. In addition to a high refractive index in a cured article, the preparation of a cured article for a Fresnel lens or a lenticular lens requires quick curing rate by active energy, and the cured article must have an excellent scratch resistance and a moderate flexibility for giving an excellent recovery property in a dent generated by compression. As resins for moulding having a high refractive index in a cured article, for example, there are disclosed compounds containing sulphur in JP-A-5255464 and JP-B-94025232, and there are disclosed compounds containing halogens such as bromine except fluorine in JP-A-5117348, there are disclosed compounds having bromine in JP-A-4216814, and further there are disclosed acrylate monomer having peculiar aromatic rings in JP-A- 5065318. However, the compounds disclosed in these JP's are peculiar, and articles moulded from these compounds are not sufficient in scratch resistance and recovery property in a dent generated by compression. In view of this situation, as a result of intensive investigations, the present inventor has found active energy ray-curable resin compositions capable of providing a cured article having a high refractive index, a high scratch resistance and an excellent recovery property in a dent generated by compression. The present invention will be described hereinafter in more detail. According to a first aspect of the present invention, there is provided an active energy ray-curable resin composition based on a urethane(meth)acrylate comprising the reaction product of: (a) an organic isocyanate having at least two isocyanate groups, (b) a polyol having a molecular weight of at least 300 which has at least two hydroxyl groups in the molecule, (c) at least one compound selected from the group consisting of compounds represented by following formulae (1) to (5) , (1) (2) (3) (4) ( 5 ) wherein R- j _ is a hydrogen atom or a methyl group, R2 is independently a hydrogen or an alkyl group having a carbon number ranging from 1 to 10, R3, R 4 , and R5 is independently a hydrogen, an alkyl group having a carbon number ranging from 1 to 10, and phenyl group or bromine, nl is an integer ranging from 1 to 7, n2 is an integer ranging from 0 to 20, Ra and Rb are independently a hydrogen or a methyl group, n3 is independently an integer ranging from 0 to 10, n4 is 0 or 1, and n5 is an integer ranging from 0 to 5. As the organic isocyanate having at least two isocyanate groups which are capable of reacting with a hydroxyl group, there are specifically exemplified isocyanates such as tolylene diisocyanate, 4,4-diphenylme hane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexylisocyanate) , 1,6-hexamethylene diisocyanate, isocyanurates such as trimer of hexamethylene diisocyanate and trimer of isophorone diisocyanate. The organic isocyanates may be employed solely or in combination. As the polyol having a molecular weight of at least 300 which has at least two hydroxyl groups in the molecule, there are specifically exemplified polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, lactone- odified polyester polyols such as a polycaprolactone polyol and a butyrolactone polyol, and polycarbonate polyols. The polyols may be employed solely or in combination. If the polyol which has at least two hydroxyl groups in the molecule has a molecular weight of less than 300, there is an unpractically decrease in flexibility of a cured article prepared from the active energy ray- curable resin composition of the present invention. As the compounds represented by the above-described general formula (1) , there are specifically exemplified 2-hydroxyethyl-2- benzene(meth)acrylate, 2-hydroxypropyl-2-benzene(meth)acrylate, 2- hydroxybutyl-2-benzene(meth)acrylate, 2-hydroxybutyl-2-(2,4, 6- 5 tribromobenzene) (meth)acrylate, 2-hydroxybutyl-2-(4- ethylbenzene) (meth)acrylate, a lactone-modified product thereof, and a reaction product of styrene oxide with a caprolactone-modified (meth)acrylate, etc. As the compounds represented by the above-described general formula 10 (2), there are specifically exemplified 2-hydroxypropyl-3- benzoate(meth)acrylate, 2-hydroxybutyl-4-benzoate (meth)acrylate, 2- hydroxypropyl-3-(2,4, 6-tribromobenzoate) (meth)acrylate, 2-hydroxypropyl-3- (4-phenylbenzoate) (meth)acrylate, a lactone-modified product thereof, and a reaction product of glycidyl(meth)acrylate with a caprolactone-modified 15 benzoic acid, etc. As the compounds represented by the above-described general formula (3), there are specifically exemplified 3-hydroxy-4-benzoate- cyclohexylmethyl(meth)acrylate, a lactone-modified product thereof, and a reaction product of 3,4-epoxycyclohexyl methyl(meth)acrylate with a 20 caprolactone-modified benzoic acid, etc. As the compounds represented by the above-described general formula (4) , there are specifically exemplified 2-hydroxypropyl-2- (meth)acryloyloxyethyl phthalate, 2-hydroxyethyl-2-(meth)acryloyloxyethyl phthalate, 2-hydroxybutyl-2-(meth)acryloyloxyethyl phthalate, etc. 25 As the compounds represented by the above-described general formula (5), there is specifically exemplified a reaction product of 2,4-diphenyl- 4-methyl-l,2-epoxypentane with (meth)acrylic acid or a caprolactone- modified (meth)acrylic acid. The compounds represented by the above-described general formulae (1) 30 to (5) may be employed solely or in combination. The compounds represented by general formulae (1) to (5) can be prepared by the reaction of acrylic acid, methacrylic acid, or a lactone- ' adduct thereof with an epoxy compound having at least one aromatic ring. The reaction is carried out in a ratio of chemical equivalent of carboxylic *35 group ranging from 0.8 to 1.2, preferably from 0.9 to 1.1, with respect to 1 chemical equivalent of an epoxy group, and at a temperature range of 60 to 150°C, preferably from 80 to 120°C Catalysts are preferably employed in order to accelerate the reaction. As examples of the catalysts, there are specifically exemplified benzylmethylamine, triethylamine, and benzyl-trimethylammonium chloride, etc. The catalysts are employed in an amount ranging from 0.1 to 10% by weight, and preferably from 0.3 to 5% by weight. In the formulae (1) to (3) and (5), the structural unit: Ra (C) COO- nl Rb is derived from a lactone compound such as epsilon-caprolactone, nl depends upon the lactone compound to be optionally employed, and n2 is the number of mole of the lactone compound to be introduced. For example, in the case when epsilon-caprolactone is employed as the lactone compound, both of Ra and Rb are a hydrogen, and nl is 5. The urethane(meth)acrylate is prepared by reaction of the components (a) , (b) , and (c) . More specifically, 1 equivalent of hydroxyl group in the component (b) is first allowed to react with from about 1.1 to 2.2 equivalent of isocyanate group in the component (a) at ordinary pressure and a temperature ranging from 60 to 90°C to prepare a urethane prepolymer. Subsequently, 1 equivalent of isocyanate group in the urethane prepolymer is allowed to react with from about 1.0 to 1.5, preferably from 1.0 to 1.2 equivalent of hydroxyl group in the component (c) at ordinary pressure and a temperature ranging from 60 to 90°C. In the case when isocyanate group in the component (a) is below 1.1 equivalent, or in the case when it exceeds 2.2 equivalents, the desired urethane prepolymer cannot be prepared, resulting in a decrease of properties, particularly, recovery property in coating layers. Furthermore, in the case when equivalent of hydroxyl group in the component (c) with respect to isocyanate group in the urethane prepolymer is below 1.0, there is an increase in residual isocyanates groups in the urethane(meth) acrylate, resulting in that it causes problems of irritating a worker and, contrarily, in the case when it exceeds 1.5, there is an increase in the residual component (c) in the urethane(meth) acrylate, resulting in that there is a decrease in the releasing property of a cured article from a mould, and there is a decrease in scratch resistance and recovery property in a cured article. Catalysts are preferably employed in order to accelerate the reaction. As examples of the catalysts, there are specifically exemplified dibutyltin dilaurate, dibutyltin diethylhexoate, dibutyltin disulphide, dibutyltin dibutoxide, etc. The catalysts are employed in an amount ranging from 50 to 5000 ppm, and preferably from 250 to 1000 ppm. Furthermore, there can be mixed a compound represented by general formula (6) described below, ( 6 ) *3 R, R. H-.C >= CH, CO ( OCHR.CH 2 ) j {-0-^ * /~ c ~ \ * /— O- f CH j CHR j O Jn- CO in order to improve the mechanical strength of a cured article prepared from the active energy ray-curable resin composition of the present invention. As the compound represented by general formula (6), it may be specifically exemplified a reaction product of modified-bisphenol type compounds such as an ethylene oxide-adduct of bisphenol A or a propylene oxide-adduct of bisphenol A with acrylic acid or methacrylic acid. In the formula (6) , the mark * represents saturation or unsaturation in the ring, R^ is independently a hydrogen or a lower alkyl group, R2 is independently a hydrogen or a methyl group, and n is an integer ranging from 1 to 10 which depends upon the amount by mole of ethylene oxide or propylene oxide to be introduced. The reaction of the modified-bisphenol A type compounds with acrylic acid or methacrylic acid is carried out in a chemical equivalent ratio ranging from 0.8 to 1.2, preferably from 0.9 to 1.1 of acrylic acid or methacrylic acid with respect to 1 chemical equivalent of hydroxyl group in the modified bisphenol A type compounds, and at a temperature range of 60 to 150, preferably from 80 to 120°C. Usual catalysts are preferably employed in order to accelerate the reaction. The compound represented by general formula (6) can be employed in an amount ranging from 5 to 60 parts by weight based on 100 parts by weight of the urethane(meth)acrylate. In the active energy ray-curable resin composition of the present invention, there can be mixed 1 to 10 parts by weight of a photo- polymerization initiator based on 100 parts by weight of the urethane(meth)acrylate. As the photo-polymerization initiator, specific examples are benzoin, benzoin methylether, benzoin isopropylether, acetophenone, 2,2-dimethoxy-2- phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1- dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-l-[4- (methylthio)phenyl] -2-morpholino-propane-l-on, 2-hydroxydi-2-methyl-1- phenylpropane-1-on, N,N-dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2- amylanthraquinone, 2-aminoanthraquinone, 2,4-diethylthioxanthone, 2,4- diisopropyl thioxanthone, acetophenone di ethylketal, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4' -bisdiethylaminobenzophenone, and Michler's ketone, etc. Furthermore, there can be optionally employed an accelerator such as ethylester of N,N-dimethylaminobenzoic acid, triethanolamine, and triethylamine, etc. The photo-polymerization initiators and accelerators may be employed solely or in combination. The photo-polymerization initiator may be employed in an amount ranging from 1 to 10 parts by weight, preferably from 3 to 6 parts by weight based on 100 parts by weight of the above-mentioned urethane(meth)acrylate. Still further, there can be employed an ethylenically unsaturated monomer other than the compounds represented by the formulae (1) to (5) in order to adjust the viscosity of the composition or to improve the properties in coating layers. As the ethylenically unsaturated monomers, examples are styrene, (meth)acrylonitrile, ethyl(meth)acrylate, butyl(meth)acrylate, 2- ethtylhexyl(meth)acrylate, isobornyl (meth)acrylate, cyclohexyl(meth)acrylate, 2-chlorostyrene, phenoxyethyl(meth)acrylate, (meth)acrylic acid, 2-hydroxyethyl(meth)acrylate, 1, 6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, etc. These ethylenically unsaturated monomers may be employed solely or in combination. The urethane(meth)acrylate to be employed in the present invention can be prepared by conventional reaction methods. Specifically, the above-described organic isocyanate having at least two isocyanate groups is allowed to react with a polyol having a molecular weight of at least 300 which has at least two hydroxyl groups in the molecule, and compounds represented by the general formulae (1) to (5) at a temperature ranging from 60 to 90°C under ordinary pressure. Catalysts are preferably employed in order to accelerate the reaction. As examples of the catalysts, there are specifically exemplified 5 dibutyltin dilaurate, dibutyltin diethylhexoate, dibutyltin sulphide, and , dibutyltin dibuthoxide, etc. The catalysts are employed in an amount ranging from 50 to 5000 ppm, and preferably from 250 to 1000 ppm. The reaction is terminated when a fixed concentration of residual isocyanate groups is reached. 10 According to a second aspect of the present invention, there is provided a cured article having a refractive index of not less than 1.47 at 25°C moulded from the active energy ray-curable resin composition. The cured article having a refractive index of not less than 1.47 at 25°C can be moulded from the active energy ray-curable resin composition of 15 the first aspect of the present invention described hereinabove. Refractive index is preferably more than 1.50 at 25°C. Refractive index can be adjusted by controlling the combination of essential and optional components to be employed in the urethane(meth)acrylates. Additivity rule based on components can be applied in refractive 20 index of the cured article as described below. Refractive index of a mixture = (the sum of respective refractive index x respective weight % in starting materials) /100. In the case when refractive index at 25°C is below 1.47, the thickness in a cured article must be unpractically increased. 25 The cured article of the present invention has not only a high refractive index but also a capability of forming flexible coating layers. Accordingly, a recovery property in a dent generated by compression is sufficient even though hands of workers or other parts are in contact with the surface when being stored and transported. 30 The cured article can be prepared by irradiating the active energy ray-curable resin composition of the present invention with ultraviolet ray or electron beam. ' Irradiation by ultraviolet ray is carried out with a mercury lamp or metal halide lamp, etc. from which curing energy of 100 to 1000 mJ/cm 2 is * 35 preferably radiated. On the other hand, irradiation by electron beam is preferably carried out at the conditions of voltage for pressurization of 150 to 250 KeV and irradiation quantity of 1 to 5 mega-rad. Irradiation is generally carried out in a resin-made mould. According to a third aspect of the present invention, there is provided a Fresnel lens or lenticular lens wherein a thermoplastic resin having a Haze value of below 10% is combined with a layer of the cured article in the second aspect. According to a fourth aspect of the present invention, there is provided a transmission type screen wherein a thermoplastic resin having a Haze value of below 10% is combined with two layers of the cured article in the second aspect. Optical lens, particularly, a Fresnel lens, a lenticular lens, and a transmission- ype screen combined thereof can be prepared by the combination of a cured article prepared from the active energy ray-curable resin composition of the present invention with a thermoplastic resin having a Haze value of not more than 10% based on JIS K7105. A Fresnel lens can be prepared by the following steps. First of all, the active energy ray-curable resin composition of the present invention is coated inside a mould for a Fresnel lens on which concentrically circular grooves are formed to prepare a coating layer having the thickness of 100 to 500 microns. Subsequently, onto the coating layer, there is stuck a plate having 50 microns to 3 mm prepared from a thermoplastic resin plate having a Haze value of not more than 10%. Subsequently, from the thermoplastic resin plate through the coating layer, irradiation is carried out to cure the coating layer, for example, with a high pressure mercury lamp from which ultraviolet ray of 400 mJ/cm 2 is radiated. Subsequently, a Fresnel lens having the thiclcness of 150 microns to 3.5 mm can be prepared by removing the mould for Fresnel lens. A lenticular lens can be also prepared with a mould for a lenticular lens similarly to the above descriptions. Specifically, the active energy ray-curable resin composition of the present invention is coated inside a mould for a lenticular lens on which minor semicylindrical projections are formed to prepare a coating layer having the thickness of 100 to 500 microns. Subsequently, from the thermoplastic resin plate side, irradiation is carried out to cure the coating layer, for example, with a high pressure mercury lamp from which ultraviolet ray of 400 mJ/cm 2 is radiated. A transmission-type screen combined thereof can be by the following steps. First of all, a Fresnel lens or a lenticular lens can be prepared as described hereinabove. Subsequently, thermoplastic resin plate in the Fresnel lens or lenticular lens is stuck on coating layer coated inside a mould for a lenticular lens or a Fresnel lens. Subsequently, irradiation is carried out to cure the coating layer. As a result, a transmission-type screen can be prepared by removing the mould for a lenticular lens or a 5 Fresnel lens . As the thermoplastic resin having a Haze value of not more than 10% based on JIS K7105, there are specifically exemplified a polymethylmethacrylate, a polystyrene, a polycarbonate, and a copolymer thereof. Of those, a polymethylmethacrylate and a polystyrene are 10 preferably employed. According to a fifth aspect of the present invention, there is provided an active energy ray-curable resin composition containing per 100 parts by weight of the combined weights of (d) , (e) , and (f) : (d) 15 to 95 % by weight of a urethane(meth)acrylate prepared from 15 an organic polyisocyanate having at least one aromatic ring or at least one alicyclic ring, and a (meth)acrylate having hydroxyl group, (e) 1 to 8 % by weight of a (meth)acrylic-based monomer having at least one bromine atom, and optionally 20 (f) a curable monomer. As the organic polyisocyanate having at least one aromatic ring or at least one alicyclic ring, there are specifically exemplified isocyanates such as tolylene diisocyanate, 4, 4-diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, methylenebis (4- 25 cyclohexylisocyanate) , isocyanurates such as a trimer of hexamethylene diisocyanate and a trimer of isophorone diisocyanate. The organic isocyanates may be employed solely or in combination. The urethane(meth)acrylate which is the component (d) can be prepared by a reaction of the above-described organic polyisocyanate with a 30 (meth)acrylate having a hydroxyl group. As the (meth)acrylate having a hydroxyl group, there are specifically exemplified 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth) crylate, 2- ' hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4- hydroxybutyl (meth)acrylate, phenoxyhydroxypropyl (meth)acrylate, an ethylene '35 oxide-modified phthalic (meth)acrylate, a propylene oxide-modified phthalic(meth)acrylate, a polyethyleneglycol mono(meth)acrylate, pentaerythritol di (meth)acrylate, pentaerythritol tri (meth)acrylate, and a lactone-modified 2-hydroxyethyl (meth)acrylate. The (meth) crylates having a hydroxyl group may be employed solely or in combination. In the reaction for the preparation of the urethane (meth) crylate which is the component (d) , polyols are additionally employed. As the polyols, there are specifically exemplified a polyethyleneglycol, a polypropyleneglycol, a polytetramethylene glycol, and a polylactone polyol, etc. The polyols may be employed solely or in combination. The reaction can be carried out by conventional processes. Specifically, at least one of the polyisocyanates, at least one of the (meth)acrylates having a hydroxyl group, and optionally at least one of the polyols, are allowed to react at ordinary pressures and at a temperature ranging from 60 to 90°C. In the reaction, there can be preferably employed catalysts such as dibutyltin dilaurate, dibutyltin diethylhexoate, and dibutyltin sulphide, etc. The catalysts are employed in an amount ranging from 50 to 5000 ppm, and preferably from 250 to 1000 ppm. The active energy ray-curable resin composition of the fifth aspect in the present invention can be prepared by mixing 15 to 95% by weight, preferably from 30 to 80% by weight of the urethane(meth)acrylate which is the component (d) with 1 to 8% by weight, preferably from 3 to 6% of a (meth) crylic-based monomer having at least one bromine atom which is the component (e) , and a curable monomer which is the component (f) . In the case when the amount of the urethane(meth)acrylate is below 15% by weight, the toughness of the cured layer unpreferably decreases and, contrarily, in the case when it exceeds 90% by weight, there is unpreferably an increase of the viscosity of the active energy ray-curable resin composition, resulting in that the composition is not appropriate for practical uses. On the other hand, in the case when the amount of the (meth)acrylic- based monomer having at least one bromine atom is below 1% by weight, the refractive index does not increase and, contrarily, in the case when it exceeds 8%, not only the scratch resistance and recovery property decrease, but also the cost of the composition disadvantageously increases. As the (meth)acrylate monomer having at least one bromine atom, there is employed at least one compound selected from the group consisting of a methyl (meth)acrylate-2,4, 6-tribromophenol, a brominated di(meth)acrylate of an ethyleneoxide adduct of bisphenol A, and compounds represented by general formulae (7) to (9) (7) (8) (9) OH wherein R ] _ is a hydrogen atom or a methyl group, R 2 is independently a hydrogen or an alkyl group having a carbon number ranging from 1 to 10, R3 , R4, and R is independently a hydrogen, an alkyl group having a carbon number ranging from 1 to 10, and phenyl group or bromine in which at least one of R T , R4, and R5 is a bromine, nl is an integer ranging from 1 to 7, n2 is an integer ranging from 0 to 20, Ra and Rb are independently a hydrogen or a methyl group, and n3 is independently an integer ranging from 0 to 10. It is to be noted that the compounds represented by the above- described general formulae (7) to (9) essentially includes at least one of bromine atom compared to the compounds represented by the above-described general formulae (1) to (3) in the first aspect in which bromine atom is not essential. Compounds (7) to (9) are prepared in the same way as compounds (1) to (3). In the active energy ray-curable resin composition of the fifth aspect of the present invention, a curable monomer which is the component (f) is optionally employed in order to adjust the viscosity of the composition and/or the properties of coating layers. As the curable monomer, there are specifically exemplified styrene, (meth)acrylonitrile, ethyl(meth)acrylate, butyl(meth)acrylate, 2- ethylhexyl(meth)acrylate, isobornyl(meth)acrylate, cyclohexyl(meth)acrylate, 2-chlorostyrene, phenoxyethyl(meth)acrylate, acrylic acid, (meth)acrylic acid, 2-hydroxyethyl(meth)acrylate, 1,6- hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra (meth)acrylate, and dipentaerythritol hexa(meth)acrylate, etc. Furthermore, the compound represented by the above-described general formula (6) is preferably added to the composition in order to improve the mechanical strength of a cured article as well as the active energy ray- curable resin composition in the first aspect. The compound represented by the general formula (6) can be employed in an amount ranging from 5 to 60% by weight based on 100 parts by weight of the components (d) , (e) , and (f) . Also in the active energy ray-curable resin composition of the fifth aspect, it may be added from 0.5 to 15 parts by weight, preferably from 3 to 8 parts by weight of the photo-polymerization initiator and accelerator described in the first aspect, based on 100 parts by weight of the components (d) , (e) , and (f) . According to a sixth aspect of the present invention, there is provided a cured article having a refractive index of not less than 1.47 at 25 3 C moulded from the active energy ray-curable resin composition in the fifth aspect. The cured article can be prepared as well as in the second aspect. According to a seventh aspect of the present invention, there is provided a Fresnel lens or lenticular lens wherein a thermoplastic resin having a Haze value of below 10% is combined with a layer of the cured article as in the sixth aspect. The Fresnel lens or lenticular lens can be prepared as well as in the third aspec . According to an eighth aspect of the present invention, there is provided a transmission type screen wherein a thermoplastic resin having Haze value of below 10% is combined with two layers of the cured article as in the sixth aspect. 5 The transmission type screen can be prepared as well as in the fourth aspect. According to a ninth aspect of the present invention, there is provided an active energy ray-curable resin composition containing: (d) at least one urethane(meth)acrylate prepared from an organic 10 polyisocyanate having at least one aromatic ring or at least one alicyclic ring, and at least one (meth)acrylate having one hydroxyl group, and (f) an ethylenic unsaturated monomer, except the bisphenol derivative of formula (6a) 15 (6a) R 3 R-, CO(OCHR 2 CH 2 ) n -0-v' /~ C— \ _ f ~°~ (CH j CHR j O ** - CO R 1, wherein ] _ is independently a hydrogen or a lower alkyl group, R 2 is independently a hydrogen or a methyl group, and n is an integer ranging from 1 to 10. The component (d) in the ninth aspect is identical to the component 20 (d) in the fifth aspect, and the component (f) in the ninth aspect is identical to the component (f) in the fifth aspect. Furthermore, the compound represented by the above-described general formula (6) , exception being made of the compound represented by formula (6a) , is preferably added to the composition in order to improve the 25 mechanical strength of a cured article as well as the active energy ray- curable resin composition as in the first and fifth aspects. The compound represented by the general formula (6) can be employed in an amount ranging ' from 5 to 60% by weight based on 100 parts by weight of the components (d) and (f) . "30 Also in the active energy ray-curable resin composition of the ninth aspect, it may be added from 0.5 to 15 parts by weight, preferably from 3 to 8 parts by weight of the photo-polymerization initiator and accelerator described in the first and fifth aspects, based on 100 parts by weight of the components (d) and (f) . According to a tenth aspect of the present invention, there is provided a cured article having a refractive index of not less than 1.47 at 25°C moulded from the active energy ray-curable resin composition in the ninth aspect. The cured article can be prepared as well as in the second and sixth aspects. According to an eleventh aspect of the present invention, there is provided a Fresnel lens or lenticular lens wherein a thermoplastic resin having a Haze value of below 10% is combined with a layer of the cured article in the ninth aspect. The Fresnel lens or lenticular lens can be prepared as well as in the third and seventh aspects. According to a twelfth aspect of the present invention, there is provided a transmission type screen wherein a thermoplastic resin having Haze value of below 10% is combined with two layers of the cured article in the ninth aspect. The transmission type screen can be prepared as well as in the fourth and eighth aspect. Furthermore, according to a thirteenth aspect of the invention, there are provided new (meth)acrylates corresponding to the compounds of formulae (3) and (5) of the first aspect of the invention. More specifically, 3- hydroxy-4-benzoate cyclohexylmethyl methacrylate, synthesised in following Synthesis Example 3 and used to prepare the urethanemethacrylate UA-8 of Synthesis Example 8, is a new compound responding to formula (3) . Also, 2- hydroxy-2,4-diphenyl-4-methyl-pentylacrylate synthesised in following Synthesis Example 4 and used to prepare the urethaneacrylate UA-9 in Synthesis Example 9, is a new compound responding to formula (5) . Finally, according to a fourteenth aspect of the invention, there are provided new brominated (meth)acrylates corresponding to the compounds of formulae (7) , (8) and (9) . These compounds are prepared in the same way as set forth for the compounds of formulae (1) to (3) . The following Examples illustrate the present invention without limiting it. The percentages are by weight. Methods of testing: (1) UV curability: A coating layer having the thickness of 200 microns was coated on a glass plate. Subsequently, the coating layer was irradiated twice by an ultraviolet ray with a power of 120W/cm and a velocity of 5m/min with a high pressure mercury lamp to prepare a cured layer. Subsequently, the cured coating layer was peeled from the glass plate. UV curability was evaluated by finger-touch. Evaluation grade is as follows. O: the absence of tackiness Δ: the presence of slight tackiness x: the presence of tackiness (2) Refractive index: Refractive index of the cured coating layer was measured with an Abbe refractometer at 25°C according to JIS K0062. (3) Elongation at break (%) and (4) Strength at break (kg/mm 2 ) : Tensile test relating to the cured coating layer was carried out at the conditions of sample length of 10 cm, marked length for measuring elongation of 6 cm, tensile speed of 100 mm/minute with a tensile tester. (5) Scratch resistance: The cured coating layer was rubbed extending over 30 mm with a metal piece in steel having a thickness of 0.2 mm and a width of 10 mm which is polished by a sandpaper. Subsequently, there was visually observed the presence or absence of scratches. o: the absence of scratches Δ: not more than 5 scratches x: more than 6 scratches (6) Recovery property of a dent: The cured coating layer was pushed at the pressure of 30 kg/cm 2 with a metal rod having the diameter of 5 mm at the point for 5 seconds, and the time after which a dent disappears was measured. < * *: disappeared immediately o: disappeared within 30 seconds Δ: disappeared within 60 seconds x: disappeared after more than 60 seconds Synthesis Example 1 A reaction vessel equipped with an agitator, a thermometer, a dropwise funnel, and an inlet for supplying dried air was placed in an oil bath, and charged with 240g (2 mole) of styrene oxide (manufactured by Daicel Chemical Industries, Ltd.) and 0.5g of triethylamine; the vessel was then heated to 90°C. Subsequently, 144g (2 mole) of acrylic acid was gradually added dropwise from the dropwise funnel, and the reaction was allowed to continue until the concentration of oxirane oxygen had decreased below 0.5%, to obtain 2-hydroxyethyl-2-phenylacrylate. Synthesis Example 2 The same procedures as in Synthesis Example 1 was followed except that 284g (2 mole) of glycidyl methacrylate were employed in place of styrene oxide and 244g (2 mole) of benzoic acid in place of acrylic acid, to obtain 2-hydroxypropyl-3-benzoate methacrylate. Synthesis Example 3 The same procedures as in Synthesis Example 2 was followed except that 392g (2 mole) of 3 , 4-epoxy cyclohexylmethyl methacrylate (Cyclomer MlOO manufactured by Daicel Chemical Industries, Ltd.) was employed in place of glycidyl methacrylate, to obtain 3-hydroxy-4-benzoate cyclohexylmethyl methacrylate. Synthesis Example 4 A warm water-jacketed reaction vessel equipped with an agitator, a thermometer, a dropwise funnel, and an inlet for supplying nitrogen gas was charged with 472g (2.2 mole) of 2,4-diphenyl-4-methyl-l-pentene; the vessel was then heated to 50 C C. Subsequently, 167g (2.2 mole) of peracetic acid was added dropwise over 1 hour and the reaction was allowed to proceed for 4 hours . After cooling to 30°C, washing by water was repeated until the acid value had decreased below 1 mg KOH/g. Volatile components were removed from the reaction product with a dryer at a reduced pressure, to obtain 2, 4-diphenyl-4-methyl-l, 2-epoxypentane. Subsequently, the same procedures as in Synthesis Example 1 was followed except that 252g (1 mole) of 2,4-diphenyl-4-methyl-l,2- epoxypentane was employed in place of styrene oxide, to obtain 2-hydroxy- 2,4-diphenyl-4-methyl-pentylacrylate. Synthesis Example 5 A reaction vessel equipped with an agitator, a thermometer, a dropwise funnel, and an inlet for supplying dried air was placed in an oil bath, and charged with 444g (2 mole) of isophorone diisocyanate and 0.5g of dibutyltin dilaurate; the vessel was then heated to 70°C. Subsequently, 53Og (1 mole) of a polycaprolactone diol having a molecular weight of 530 (Placcel 205 manufactured by Daicel Chemical Industries, Ltd.) was gradually added from the dropwise funnel. After the completion of addition, the reaction was allowed to continue until the concentration of residual isocyanate groups attained a theoretical value. Subsequently, 616g (2 mole) of 2-hydroxyethyl-2-acryloyloxyethyl phthalate (Biscoat 2308 manufactured by Osaka Yuki Industries, Ltd.) was added. After the completion of addition, the reaction was allowed to continue until the concentration of the residual isocyanate groups attained a value below 0.1%, to obtain a urethaneacrylate (hereinafter, referred to as UA-5) . Synthesis Example 6 The same procedures as in Synthesis Example 5 was followed except that 384g (2 mole) of 2-hydroxyethyl-2-phenylacrylate obtained in Synthesis Example 1 was employed in place of 2-hydroxyethyl-2-acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-6) . Synthesis Example 7 The same procedures as in Synthesis Example 5 was followed except that 528g (2 mole) of 2-hydroxypropyl-3-benzoate methacrylate obtained in Synthesis Example 2 was employed in place of 2-hydroxyethyl-2- acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-7) . Synthesis Example 8 The same procedures as in Synthesis Example 5 was followed except that 636g (2 mole) of 3-hydroxy-4-benzoate cyclohexylmethyl methacrylate obtained in Synthesis Example 3 was employed in place of 2-hydroxyethyl-2- acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-8) . Synthesis Example 9 The same procedures as in Synthesis Example 5 was followed except that 648g (2 mole) of 2-hydroxy-2,4-diphenyl-4-methyl-pentylacrylate obtained in Synthesis Example 4 was employed in place of 2-hydroxyethyl-2- acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-9). Synthesis Example 10 The same procedures as in Synthesis Example 5 was followed except that 348g (2 mole) of tolylene diisocyanate was employed in place of isophorone diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-10) . Synthesis Example 11 The same procedures as in Synthesis Example 5 was followed except that 336g (2 mole) of hexamethylene diisocyanate was employed in place of isophorone diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-11) . Synthesis Example 12 The same procedures as in Synthesis Example 5 was followed except that 524g (2 mole) of methylenebis-4-cyclohexylisocyanate was employed in place of isophorone diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-12) . Synthesis Example 13 The same procedures as in Synthesis Example 5 was followed except that 508g (2 mole) of 4,4-diphenyl methane diisocyanate was employed in place of isophorone diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-13). Synthesis Example 14 The same procedures as in Synthesis Example 5 was followed except that 600g (1 mole) of a polyethylene glycol having an average molecular weight of 600 was employed in place of the polycaprolactone diol, to obtain a urethaneacrylate (hereinafter, referred to as UA-14) . Synthesis Example 15 The same procedures as in Synthesis Example 5 was followed except that 500g (1 mole) of a polycarbonate diol having an average molecular weight of 500 (CD-205 manufactured by Daicel Chemical Industries, Ltd.) was employed in place of the polycaprolactone diol, to obtain a urethaneacrylate (hereinafter, referred to as UA-15) . It is to be noted that the polycarbonate diol (CD-205) has a chemical formula of HO- (CH 2 ) 6 -[-0C0(CH 2 )0-] n -H. Synthesis Example 16 The same procedures as in Synthesis Example 5 was followed except that 232g (2 mole) of hydroxyethyl acrylate (HEA) was employed in place of 2-hydroxyethyl-2-acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-16) . Synthesis Example 17 The same procedures as in Synthesis Example 5 was followed except that 688g (2 mole) of an epsilon-caprolactone-modified 2-hydroxyethyl acrylate (PCL FA-2 manufactured by Daicel Chemical Industries, Ltd.) was employed in place of 2-hydroxyethyl-2-acryloyloxyethyl phthalate, to obtain a urethaneacrylate (hereinafter, referred to as UA-17) . Synthesis Example 18 The same procedures as in Synthesis Example 5 was followed except that 696g (2 mole) of pentaerythritol triacrylate (PETIA manufactured by Daicel-UCB, Ltd.) was employed in place of 2-hydroxyethyl-2- acryloyloxyethyl phthalate, to obtain a urethane acrylate (hereinafter, referred to as UA-18) . Examples 1 to 18 and Comparative Examples 1 to 5 Resin compositions were prepared according to respective mixing ratio (parts by weight) as shown in Tables 1 and 2, and the properties of coating layers cured by ultraviolet ray were evaluated. Results are shown in Tables 1 and 2. Table 2 Comparative Example 1 2 3 4 5 UA-5 100 UA-lβ 100 100 UA-17 100 UA-18 100 EOMDA 30 IBOA-B 50 20 50 50 50 MATBP 15 DC-1173 6 6 6 6 6 property (1) o o o o c (2) 1.45 1.46 1.45 1.45 1.55 (3) 70 60 120 40 75 (4) 1.88 2.13 0.97 3.08 0.88 (5) Δ Δ Δ o x (6) A Δ o X x In the Tables 1 and 2, abbreviations and (numbering) are as follows: UA-5 to UA-18: urethane(meth)acrylates prepared in Synthesis Examples 5 to 18 EOMDA: an ethylene oxide-modified bisphenol type diacrylate (n=l-10) which is EB-150 manufactured by Daicel-UCB, Ltd. IBOA-B: isobornyl acrylate which is IBOA-B manufactured by Daicel-UCB, Ltd. BMA: benzylmethacrylate PEA: phenoxyethyl acrylate DPEHA: dipentaerythritol hexaacrylate MATBP: l-methylacrylate-2, 4, 6-tribromophenol DC-1173 2-hydroxy-2-meth-l-phenylpropane-l-on which is Darocure 1173 manufactured by Ciba-Geigy, AG. (1) UV curability (2) Refractive index of cured coating layer at 25°C (3) Elongation at break (%) (4) Strength at break (kg/mm 2 ) (5) Scratch resistance (6) Recovery property of a dent Synthesis Example 19 A reaction vessel equipped with an agitator, a thermometer, a dropwise funnel, and an inlet for supplying dried air was placed in an oil bath, and charged with 348g (2 mole) of 2,4-tolylene diisocyanate and 0.5g of dibutyltin dilaurate, and the vessel was then heated to 70°C. Subsequently, 688g (2 mole) of an epsilon-caprolactone-modified 2- hydroxyethyl acrylate having a molecular weight of 344 (PCL FA-2 manufactured by Daicel Chemical Industries, Ltd.) was added dropwise from the dropwise funnel. After adding dropwise, the reaction was allowed to continue until the concentration of residual isocyanate groups reached a value below 0.1%, to obtain a urethaneacrylate (hereinafter, referred to as UA-19) . Synthesis Example 20 The same procedures as in Synthesis Example 19 was followed except that 444g (2 mole) of isophorone diisocyanate was employed in place of 2,4- tolylene diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-20) . Synthesis Example 21 The same procedures as in Synthesis Example 19 was followed except that 362g (2 mole) of hexamethylene diisocyanate was employed in place of tolylene diisocyanate, to obtain a urethaneacrylate (hereinafter, referred to as UA-21) . Examples 19 to 21 and Comparative Examples 6 and 7 Resin compositions were prepared according to respective mixing ratio (parts by weight) as shown in Table 3. The properties of coating layers cured by an ultraviolet ray were then evaluated. Results are shown in Table 3. Table 3 Example Comparative Example 19 20 21 6 7 UA-19 65 - 45 - - UA-20 - 65 - - - UA-21 - - - 65 70 MATBP 5 5 5 5 - MBPADA - - 20 - - EA 30 30 30 30 30 IC 184 6 6 6 6 6 (1) o o o o o (2) 1.50 1.49 1.52 1.45 1.46 (3) 120 100 90 130 100 (4) 1.24 1.55 1.83 1.07 1.61 (5) o o o o Δ (6) <3> ® < * » x X In the Table 3, abbreviations and (numbering) are as follows: MATBP: l-methylacrylate-2,4, 6-tribromophenol MBPADA: a modified bisphenol type diacrylate which is one of the compounds represented by the general formula (6) . EA: ethylacrylate IC 184: 1-hydroxycyclohexyl phenylketone which is Irugacure 184 manufactured by Ciba-Geigy, AG. (1) UV curability (2) Refractive index of cured coating layer at 25°C (3) Elongation at break (%) (4) Strength at break (kg/mm 2 ) (5) Scratch resistance (6) Recovery property of a dent Examples 22 to 25 and Comparative Examples 8 and 9 Resin compositions were prepared according to respective mixing ratio (parts by weight) as shown in Table 4. The properties of coating layers cured by ultraviolet ray were then evaluated. Results are shown in Table 4. Table 4 Example Comparative Example 22 23 24 25 8 9 UA-19 100 100 - - - - UA-20 - - 100 100 - - UA-21 - - - - 100 100 IBOA-B 20 20 20 20 20 20 MBPADA - 30 - 30 - 30 DC 1173 6 6 6 6 6 6 (1) o o o o o O (2) 1.52 1.53 1.50 1.51 1.45 1.46 (3) 90 75 85 80 110 85 (4) 1.66 1.98 1.43 1.76 1.88 2.13 (5) o o o o X (6) ® ® ® X X In the Table 4 , abbreviations and (numbering) are as follows : IBOA-B : isobornyl acrylate manufactured by Daicel-UCB, Ltd. MBPADA : an ethylene oxide-modified bisphenol type diacrylate which is EB-150 (n=l-10) manufactured by Daicel-UCB, Ltd. DC 1173 2-hydroxy-2-meth-l-phenylpropane-l-on which is Darocure 1173 manufactured by Ciba-Geigy, AG. (1 UV curability (2 Refractive index of cured coating layer at 25°C (3 Elongation at break (%) (4 Strength at break (kg/mm 2 ) (5 Scratch resistance (6 Recovery property of a dent While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims: CLAIMS An active energy ray-curable resin composition based on a urethane(meth)acrylate comprising the reaction product of: (a) an organic isocyanate having at least two isocyanate groups, (b) a polyol having a molecular weight of at least 300 which has at least two hydroxyl groups in the molecule, (c) at least one compound selected from the group consisting of compounds represented by following formulae (1) * to (5) , (1) (2) (3) OH ( 4 ) ( 5 ) wherein R^_ is a hydrogen atom or a methyl group, R 2 is independently a hydrogen or an alkyl group having a carbon number ranging from 1 to 10, R3, R 4 , and R 5 is independently a hydrogen, an alkyl group having a carbon number ranging from 1 to 10, and phenyl group or bromine, nl is an integer ranging from 1 to 7, n2 is an integer ranging from 0 to 20, Ra and Rb are independently a hydrogen or a methyl group, n3 is independently an integer ranging from 0 to 10, n4 is 0 or 1, and n5 is an integer ranging from 0 to 5. 2. An active energy ray-curable resin composition containing, per 100 parts by weight of the combined weight of (d) , (e) , and (f) : (d) 15 to 95 % by weight of a urethane(meth)acrylate prepared from an organic polyisocyanate having at least one aromatic ring or at least one alicyclic ring, and a (meth)acrylate having an hydroxyl group, (e) 1 to 8 % by weight of a (meth)acrylic-based monomer having at least one bromine atom, and optionally, (f) a curable monomer. An active energy ray-curable resin composition as set forth in claim 2, wherein said (meth)acrylic-based monomer having at least one bromine atom is at least one compound selected from the group consisting of a methyl (meth)acrylate-2 , 4, 6-tribromophenol, a brominated di (meth)acrylate of an ethylene oxide adduct of bisphenol A, and compounds represented by general formulae (7) to (9) (7) (8) (9) wherein R 1 is a hydrogen atom or a methyl group, R 2 is independently a hydrogen or an alkyl group having a carbon number ranging from 1 to 10, R 3 , R 4 , and R 5 is independently a hydrogen, an alkyl group having a carbon number ranging from 1 to 10, and phenyl group or bromine in which at least one of R 3 , R 4 , and R 5 is a bromine, nl is an integer ranging from 1 to 7, n2 is an integer ranging from 0 to 20, Ra and Rb are independently a hydrogen or a methyl group, n3 is independently an integer ranging from 0 to 10. 4. An active energy ray-curable resin composition containing: (d) at least one urethane(meth)acrylate prepared from an organic polyisocyanate having at least one aromatic ring or at least one alicyclic ring, and at least a (meth)acrylate having one hydroxyl group, and (f) an ethylenic unsaturated monomer, except the bisphenol derivative of formula (6a) . (6a) wherein R^ is independently a hydrogen or a lower alkyl group, R2 is independently a hydrogen or a methyl group, and n is an integer ranging from 1 to 10. 5. An active energy ray-curable resin composition as set forth in any of claims 1 to 4, wherein 100 parts by weight of said urethane (meth)acrylate is mixed with 5 to 60 parts by weight of a compound represented by general formula (6), (6) wherein the mark * represents saturation or unsaturation in the ring, R- j _ is independently a hydrogen or a lower alkyl group, R 2 is independently a hydrogen or a methyl group, and n is an integer ranging from 1 to 10. 6. An active energy ray-curable resin composition as set forth in any of claims 1 to 5, wherein 100 parts by weight of said urethane (meth)acrylate is mixed with 1 to 10 parts by weight of a photo¬ polymerization initiator. 7. A cured article having a refractive index of not less than 1.47 at 25°C moulded from an active energy ray-curable resin composition as set forth in any of claims 1 to 6. 8. A Fresnel lens or lenticular lens wherein a thermoplastic resin having a Haze value of below 10% is combined with a layer of the cured article as set forth in claim 7. 9. A Fresnel lens or lenticular lens as set forth in claim 8, wherein said thermoplastic resin is a methylmethacrylic resin. 10. A transmission type screen wherein a thermoplastic resin having a Haze value of below 10% is combined with two layers of the cured article as set forth in claim 7. 11. A transmission type screen as set forth in claim 10 wherein said thermoplastic is a methylmethacrylic resin. 12. (Meth)acrylates represented by formulae (3) and (5) in claim 1. 13. 3-hydroxy-4-benzoate cyclohexylmethyl methacrylate and 2-hydroxy-2, - diphenyl-4-methyl-pentylacrylate, according to claim 12. 14. Brominated (meth)acrylates represented by formulae (7), (8) and (9) in claim 3.

Inventors: KOCHI MICHIO, KOCHI, MICHIO
Applicants: KOCHI MICHIO, UCB SA, KOCHI, MICHIO, UCB, S.A.
Application year: 1996
Main classification: C08G18
IPC codes: C08F283, C08G18, G02B1