WO2006057413A1 - Photocurable resin composition and optical member - Google Patents

Abstract

Disclosed is an ultraviolet curable resin composition containing an urethane(meth)acrylate (A) obtained by reacting a hydroxylated (meth)arylate (a) and an organic polyisocyanate (b) and then further reacting a diol (c) represented by the formula (1) below; an ethylenically unsaturated group-containing compound (B) other than the component (A); and a photopolymerization initiator (C). This ultraviolet curable resin composition is characterized in that a cured product thereof has an Abbe number of not less than 40 and a refractive index (nD25) at 589 nm of not less than 1.55.

Description

 Specification

 Photocurable resin composition and optical member

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a photocurable resin composition, and more specifically, a prism lens sheet used for a backlight of a liquid crystal display device, a Fresnel lens sheet used for a screen of a projection television, and a lenticular lens. The present invention relates to a photocurable resin composition useful for forming a lens portion of a lens sheet such as a sheet, or an optical member such as a backlight using such a sheet, and an optical member made of the cured product.

 Background art

 Conventionally, lenses such as Fresnel lenses and lenticular lenses have been manufactured by techniques such as a press method and a cast method, but both methods require a long time to manufacture the lenses and have poor productivity. In order to solve such problems, in recent years, studies have been made on the production of lenses using ultraviolet curable resins. Specifically, an ultraviolet curable resin composition is poured between a lens-shaped mold and a transparent resin substrate, and the lens is irradiated in a short time by irradiating ultraviolet rays from the substrate side to cure the composition. Can be manufactured. Furthermore, with the recent thinning and enlargement of projection televisions and video projectors, various proposals according to various lens characteristics, such as higher refractive index and mechanical characteristics, can be applied to the resin forming the lens. Consideration has been made. For example, Patent Document 1 discloses that (A) diol (a) obtained by reacting bisphenol A and alkylene oxide is reacted with aromatic organic polyisocyanate (b), and then hydroxyl group-containing. Urethane (meth) acrylate which is a reaction product obtained by reacting (meth) acrylate (c), (B) an ethylenically unsaturated group-containing compound other than (A) component, and (C) a photopolymerization initiator An ultraviolet curable resin composition for a transmission type screen is described.

 Patent Document 1: Japanese Patent Laid-Open No. 5-255464

[0004] However, such conventional ultraviolet curable resin compositions have required characteristics required for lenses such as refractive index, adhesion to various plastic substrates, releasability from molds, and resilience. A sufficiently satisfactory cured product could not be obtained. In general, the refractive index of the organic material is larger on the short wavelength side (up to 365 nm) than on the long wavelength side (from 589 nm). Therefore, a lens made of an organic material can easily refract short wavelength light (blue) more greatly than long wavelength light (red). In recent years, thin-type rear projection TVs, which are the mainstream, have a sharp incident angle of light from the light source to the Fresnel lens, and short wavelength light is refracted more remarkably.

 An object of the present invention is to provide a resin for a Fresnel lens and a rear processing TV Fresnel lens with improved blue loss on a rear process TV screen. Disclosure of the invention

 Means for solving the problem

[0005] In order to solve the problems in such a conventional photocurable resin composition, the present inventors have intensively studied, and as a result, urethane (meta) composed of a diol having a specific structure by a certain process. Various plastic substrates with a high refractive index can be obtained by producing a cured product using an ultraviolet curable resin composition in which atallate, other ethylenically unsaturated group-containing compound, and a photopolymerization initiator are combined. It was found that a transmissive screen such as a Fresnel lens or a lenticular lens can be obtained.

 Furthermore, it has been found that by setting the Abbe number and the refractive index at 589 nm of the cured product obtained by curing the above-mentioned ultraviolet curable resin composition to a specific value or more, the problem of blue loss can be improved. The invention has been completed.

That is, the present invention provides the following ultraviolet curable resin composition and a rear project using the same.

[1] The following components (A), (B) and (C):

 (A) (a) hydroxyl group-containing (meth) acrylate and (b) organic polyisocyanate are reacted, then (c) formula (1)

[Chemical 1]

(Wherein, R ¹ represents a hydrogen atom, a methyl group, or Echiru group, Yogu even if Mashimashi these mixed to R ¹ in one molecule, however, R ¹ of at least 50 mol% of all R ¹ Is other than a hydrogen atom, R ² represents a hydrogen atom or a methyl group, and m and n each represent a number from 1 to 20.

G;

 (B) an ethylenically unsaturated group-containing compound other than the component (A);

 (C) Photopolymerization initiator

A UV curable resin composition containing a curable resin, wherein the cured product has an Abbe power of 40 or more and a refractive index (n ²⁵ ) at 589 nm of 1.55 or more.

 D

An ultraviolet curable resin composition.

 [2] The ultraviolet curable resin composition according to the above [1], wherein the average value of the Abbe number of the component (B) is 41 or more.

 [3] The ultraviolet curable resin composition according to the above [1], wherein the molecular weight of the component (A) is 350 or more.

 [4] The ultraviolet curable resin composition according to any one of [1] to [3], which is used for forming an optical member.

 [5] A rear projection TV Fresnel lens comprising a cured product of the ultraviolet curable resin composition according to any one of [1] to [4] above.

 According to the ultraviolet curable resin composition of the present invention, the required characteristics required for a lens such as adhesion to various plastic substrates, mold force peelability, coatability (viscosity), and resilience are sufficiently satisfied. A cured product can be provided.

 The cured product obtained by curing the ultraviolet curable resin composition of the present invention can improve blue loss particularly in a thin rear-projection TV, and can improve image quality.

BEST MODE FOR CARRYING OUT THE INVENTION [0008] Hereinafter, the present invention will be described in detail.

 I. UV curable resin composition

 (A) component

 The component (A) used in the ultraviolet curable resin composition of the present invention comprises: (a) a hydroxyl group-containing (meth) acrylate and (b) an organic polyisocyanate, and then (c) It is urethane (meth) acrylate which is a reaction product obtained by reacting the diol represented by the formula (1).

 [0009] Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2 hydroxy-3 phenyl. Oxypropyl (meth) acrylate, 1, 4 butanediol mono (meth) acrylate, 2 Hydroxyalkyl (meth) attaylloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 1, 6-hexanediol Mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylol ethanedi (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (Meta) Atarirate The following formula (3)

[0010] [Chemical 2] (3)

[0011] (In the formula, R ⁸ represents a hydrogen atom or a methyl group, V represents a number of:! To 15), and the like. A compound obtained by an addition reaction between a glycidyl group-containing compound such as alkyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate, and (meth) attalinoleic acid can also be used. These hydroxyl group-containing (meth) acrylates may be used alone or in combination of two or more.

[0012] Examples of the organic polyisocyanate include 2, 4_tolylene diisocyanate, 2, 6-tolylene diisocyanate, 1,3_xylylene diisocyanate, and 1,4_xylylene diisocyanate. 1, 5 _Naphthalenediisocyanate, m-Phenylene diisocyanate, p -Phenylene diisocyanate, 3, 3 '-Dimethyl _4, 4' -Diphenylmethane diisocyanate, 4, 4 Examples include '-diphenylmethane diisocyanate, 3,3,1 dimethylphenylene diisocyanate, 4,4'-biphenyl diisocyanate, and the like. In particular, 2, 4_ birds It is preferable to use range isocyanate, 2, 6_tolylene diisocyanate, 1,3_xylylene diisocyanate, 1,4_xylylene diisocyanate.

Furthermore, the diol is represented by the above formula (1). In the formula (1), R ¹ is a hydrogen atom, a methyl group, or an ethyl group, and these may be mixed in R ¹ in one molecule, but 50 mol% or more of the total R ¹ R ¹ is other than a hydrogen atom. The ratio in which R ¹ is other than a hydrogen atom is preferably at least 60 mol%, more preferably at least 80 mol%, particularly preferably at least 90 mol%, and most preferably all R ¹ are methyl groups. Preferred. If 50 mol% or more of R ¹ is a hydrogen atom, the adhesion to the substrate is lowered, and when a lens is formed, there is a risk of causing a problem when the lens is peeled off from the substrate and used as a lens. R ² represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable. m and n are each a number from 1 to 20, and the average power of m + n is preferably 4 to 30, especially 6 to 25. When the average value of m + n is 2 or less, the adhesion to the substrate is lowered. Conversely, when it exceeds 40, it is difficult to obtain the refractive index required for the lens. Among the above-mentioned diols, examples of commercially available products include Uniunore DB-360, DB-400, DB-800, DB-900 (above, Nippon Oil & Fats Co., Ltd.).

 [0014] The urethane (meth) acrylate (A) is produced by first reacting a hydroxyl group-containing (meth) acrylate and an organic polyisocyanate and then reacting the diol in the next step. In other production methods, such as adding all components at once or reacting the organic isocyanate and diol first, then reacting the hydroxyl group-containing (meth) acrylate, the viscosity becomes high and difficult to handle. Since it may become, it is not preferable.

[0015] At this time, the diol, the organic polyisocyanate, and the hydroxyl group-containing (meth) acrylate are used in proportion to the isocyanate group contained in the organic polyisocyanate compound with respect to 1 equivalent of the hydroxyl group contained in the diol. 1 .:! ~ 2 equivalents, It is preferable that the hydroxyl group of the hydroxyl group-containing (meth) acrylate is 0.:!~1 equivalents. Furthermore, 1.3 to 2 equivalents of the isocyanate group contained in the organic polyisocyanate compound and 0.3 to 1 equivalent of the hydroxyl group of the hydroxyl group-containing (meth) acrylate with respect to 1 equivalent of the hydroxyl group contained in the diol It is particularly preferable that If it is out of this preferred range, it becomes difficult to handle in a liquid state due to an increase in viscosity. [0016] When producing the urethane (meth) acrylate, usually, copper naphthenate, cobalt naphthenate, zinc naphthenate, di-dilaurate, n_butyltin, triethylenamine, triethylenediamine _ 2 _ A urethanization catalyst such as methyltriethyleneamine is used in an amount of 0.0 :! to 1% by mass based on the total amount of the reaction raw materials. The reaction temperature is usually 10 to 90 ° C, preferably 30 to 80 ° C.

 [0017] The preferred number average molecular weight of the urethane (meth) acrylate of component (A) is 500 to 20,000, and preferably 1,000 to 15,000. If the number average molecular weight of the component (A) urethane (meth) acrylate is less than 500, the adhesion of the cured product obtained by curing the resin composition to the substrate is lowered, and conversely the number average When the molecular weight exceeds 20,000, the viscosity of the resin composition becomes high and it is difficult to handle.

 [0018] The urethane (meth) acrylate of component (A) is preferably added in an amount of 5 to 70% by mass, particularly preferably 10 to 60% by mass, in the total resin composition. The lower limit of the blending amount is preferably in the above range from the viewpoint of imparting appropriate mechanical properties such as toughness to the cured product and imparting adhesion to the substrate. In addition, the upper limit of the blending amount is preferably in the above range from the viewpoint of preventing the viscosity of the composition from increasing and deteriorating workability and coating property.

 [0019] Component (B)

The component (B) used in the ultraviolet curable resin composition of the present invention is an ethylenically unsaturated group-containing compound other than the component (A), and a compound containing a (meth) atalyloyl group or a bur group. (Hereinafter referred to as “unsaturated monomer”) can be used. As such an unsaturated monomer, a monofunctional monomer and a polyfunctional monomer can be used. Examples of monofunctional monomers include N-Buylpyrrolidone, N-Buyl Prolactam, vinyl imidazole, and Bulpyridine. Monomers: isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentyl (meth) acrylate, cyclohexyl (Meth) Atalylate, Benzyl (Meth) Atalylate, 4-Butylcyclohexyl (Meth) Atalylate, Atariloy Noremonorephorine, 2-Hydroxyethyl (meth) atarylate, 2-Hydroxypropyl (meth) atalylate, 2- Hydroxybutyl (meth) Atarire DOO, methyl (meth) Atari rate, Echinore (meth) Atari rate, propyl (meth) Atari rate, isopropyl (meth) Atari rate, butyl ( 'Relate, aminore (meth) acrylate, isobutyl (meth) acrylate, t_butyl (meth) acrylate, pentyl (meth) acrylate, isoamino acrylate (meth) acrylate, hexyl (meth) acrylate, heptyl ( (Meth) acrylate, octyl (meth) acrylate, isooctanol (meth) acrylate, 2_ethyl hexyl (meth) acrylate, nonyl (meth) acrylate

, Dodecyl (meth) acrylate, lauryl (meth) acrylate, stearinole (meth) acrylate chill (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono ( (Meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) alkyl

—Dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, jetylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, N, N-Jetyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, hydroxybutyl building ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethyl hexyl vinyl ether and the following formulas (4), (5)

[0020] [Chemical 3]

(Wherein R ⁹ represents a hydrogen atom or a methyl group, R ^1Q represents an alkylene group having 2 to 8 carbon atoms)

, W: indicates the number of! ~ 8)

[0022] [Chemical 4]

( Five )

[0023] (wherein R ¹¹ and each independently represents a hydrogen atom or a methyl group, R ¹² represents an alkylene group having 2 to 8 carbon atoms, and X represents a number of 1 to 8). Monofunctional monomers, etc.

 [0024] trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate , Tris (2-hydroxychetyl) isocyanurate tri (meth) acrylate, Tris (attaroyloxy) iso

Di (meth) talylate of diol, which is an adduct of polyethylene oxide or propylene oxide of bis (r) hexa (meth) acrylate, bisphenol A, Di of diol, which is an adduct of ethylene oxide or propylene oxide of bisphenol A (Meth) acrylate, bisphenol A diglycidyl ether and polyfunctional monomers such as epoxy (meth) acrylate and triethylene glycol divinyl ether obtained by carotenating (meth) acrylate.

[0025] As a result of intensive studies, the cured product has an Abbe number of 40 or more and a refractive index ( _n ²⁵ ) at 589 nm of 1.55 or more. Adhesion, cured product

D

 It was found that a monomer having a tricyclodecane group is essential in order to obtain a composition satisfying all of the restorability, and that the content is 10 parts by weight or more.

[0026] Among the examples of component (B), the Abbe number of the cured product obtained by curing the composition of the present invention is 40 or more, and the refractive index (n ²⁵ ) at 589 nm is 1.55 or more. For each (B)

 D

 The Abbe number per minute is preferably 40 or more, more preferably 50 or more, and particularly preferably 60 or more. However, when a plurality of components (B) are used in combination, the component (B) having an Abbe number force of less than S40 may be used in a range that does not lower the Abbe number of the cured product to less than 40.

[0027] The refractive index of each component (B) is preferably 1.54 or more, more preferably 1.55 or more, and particularly preferably 1.56 or more. However, multiple When the component (B) is used in combination, the component (B) having a refractive index of less than 1.54 may be used in a range that does not lower the Abbe number of the cured product to less than 40.

[0028] From the viewpoint of the Abbe number and the refractive index, preferable monofunctional monomers include N-bule force prolatatum (Abbe number 47.1, refractive index 1.54), attalyleuno monomonophorin (Abbe number 44.4). And the refractive index 1.55). Likewise, preferred polyfunctional monomers include trimethylol propanetriatalylate (Abbe number 45.7, refractive index 1.51), dipentaerythritol hexaatalylate (Abbe number 51.3, refractive index 1.50), tris ( Atari mouth kichetil) isocyanurate (Abbe number 53.0, refractive index 1.53), nonanediol ditalylate (Abbe number 57.7, refractive index 1 · 50), tricyclodecane-3,8-di

 And ethyl dimethyldiatalylate (Abbe number 62.0, refractive index 1.53).

[0029] Examples of commercially available monofunctional monomers include New Frontier PHE (Daiichi Kogyo Seiyaku).

 ), ALONIX M110, M120, M150, M156 (above, manufactured by Toagosei Co., Ltd.), LA, IBXA, 2—MTA, HPA, Pisco Ichigo # 150, # 155, # 158, # 190, # 2000, # 2100, # 2150 (Osaka Organic Chemical Industry Co., Ltd.), Light Atylate BO— A, EC— A, DMP— A, THF— A, HOP— A, HOA— MPE, HOA— MPL (above, manufactured by Kyoeisha Igaku Co., Ltd.), KAYARAD TCI 1 OS (produced by Nippon Kayaku Co., Ltd.), FA—511A, 512A, 513A (above, manufactured by Hitachi Chemical Co., Ltd.), VP (BASF Co., Ltd.), ACMO, DMAA, DM APAA (manufactured by Kojin Co., Ltd.) and the like.

[0030] In addition, commercially available products of polyfunctional monomers include, for example, New Frontier LA-9A (Daiichi Kogyo Seiyaku Co., Ltd.), Neopol V779 (Nippon Cupica), Upimar UV SA1002, SA 2007 (above, Mitsubishi Chemical) (Made by Co., Ltd.), Biscote # 195, # 230, # 215, # 260, # 335HP, # 295, # 300, # 360, # 700, GPT, 3PA (above, made by Osaka Organic Chemicals Co., Ltd.) ), Light acrylate 4EG—A, 9EG—A, NP—A, DCP—A, BP—4EA, B P_4PA, TMP_A, PE_3A, PE_4A, DPE—6A (above, manufactured by Kyoeisha Chemical Co., Ltd.), KAYARAD PET-30, TMPTA, R-604, DPHA, DPCA-20, -30, -60, -120, HX-620, D-310, D-330 (above, manufactured by Enomoto Yakuyaku Co., Ltd.) Allonics M208, M210, M215, M220, M240, M305, M309, M310, M315, M32 5, M400 (above, manufactured by Toagosei Co., Ltd.), Lipoxy VR-77, VR-60, VR-90 (above, Showa Polymer Co., Ltd.).

[0031] Among the components (B) used in the present invention, in order to achieve the refractive index required for the lens,

It is preferable to use a (meth) acrylate represented by

[0032] [Chemical 5]

[0033] (wherein R ³ represents a hydrogen atom or a methyl group, R ⁴ represents — (〇CH 2 CH 3) p—, − (OCH

 twenty two

CH (CH))-or OCH CH (OH) CH-, each R ⁵ is independently hydrogen

2 3 q 2 2

An atom or a halogen atom excluding fluorine, R ⁶ is a hydrogen atom, a halogen atom excluding fluorine, or Ph_C (CH 2) —, Ph— (where Ph represents a phenyl group), carbon number 1 ~ 20

 3 2

 And p and q each represent a number from 1 to 10)

[0034] For example, phenoxychetyl (meth) acrylate, phenoxy_2_methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2 —Fueurphenoxychetyl (meth) atarylate, 4_Fueurphenoxychetyl (meth) atalylate, 3-(2 _Fuylphenyl) _ 2 _Hydroxypropyl (meth) atalylate, ethylene oxide (Meth) atarylate of p_tamylphenol, 2-bromophenoxychetyl (meth) ate, 2,4-dibromophenoxytetyl (meth) ate, 2, 4, 6-tribromophenol Phenoxy modified with multiple moles of chill (meth) acrylate and ethylene oxide and propylene oxide ( Data) Atari rate, and the like. Among them, particularly preferred are phenoxychetyl (meth) acrylate, phenoxy ethoxy ethyl (meth) acrylate, phenoxy phthalate modified with 4 moles of ethylene oxide, and (meth) acrylate of p-tammyl phenol reacted with ethylene oxide.

[0035] Commercially available products include Alonics M101, M102, M110, Mll, M113, M117, M5700, T〇-1317 (above, manufactured by Toagosei Co., Ltd.), Biscote # 192, # 193, # 220 (above , Osaka Organic Chemical Co., Ltd.), KAYARAD R—564, R—128H Nippon Kayaku Co., Ltd.), NK ester AMP_10G, AMP-20G (above, Shin-Nakamura Chemical Co., Ltd.), Light Atarylate P〇A, P_200A, NP-4EA, NP-8EA, Epoxy STELL M-600A (above, manufactured by Kyoeisha Chemical Co., Ltd.), PHE, CEA, PHE_2, BR_31, BR_31M, BR_32 (above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

 [0036] Component (B) is preferably blended in the total composition in an amount of 10 to 70 mass%, particularly preferably 20 to 60 mass%. The lower limit of the amount is preferably in the above range from the viewpoint of the viscosity of the composition and the refractive index of the cured product. The upper limit of the blending amount is preferably within the above range in terms of maintaining sufficient mechanical properties and coating strength.

 [0037] Component (C)

 The ultraviolet curable resin composition of the present invention is cured by ultraviolet rays. The photocuring reaction requires a photopolymerization initiator as component (C), and if necessary, a photosensitizer is further added. Any photopolymerization initiator may be used as long as it can be decomposed by light irradiation to generate radicals to initiate polymerization. For example, acetophenone, acetophenone benzil ketal, 1-hydroxycyclohexyl phenyl ketone, 2, 2 —Dimethoxy-2-phenacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-clobenzobenzophenone, 4, 4'-dimethoxybenzophenone 4, 4'-Diaminobenzophenone, Michlerketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1 _ (4-isopropylphenyl) _ 2-hydroxy-1-2_methylpropane-1-one , 2-hydroxy mono 2_methyl _ 1 _ Enylpropane _ 1 _one, thixanthone, dimethylthioxanthone, 2 _isopropyl thixanthone, 2 _cyclothiaxanthone, 2 —methyl 1 1 _ [4- (methylthio) phenyl] _ 2_morpholino 1 propane 1 1-one 2, 4, 6_trimethylbenzoyldiphenylphosphine oxide, bis_ (2,6_dimethyoxybenzoyl) _2, 4, 4_trimethylpentylphosphine oxide, etc.

[0038] Commercially available photopolymerization initiators include, for example, Irgacurel 84, 369, 651, 500, 819, 9 07, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1116, 1173 ( Ciba 'Specialty' Chemicals Co., Ltd.), Lucirin TP〇, LR8893 LR8970 (manufactured by BASF Corp.), ubecryl P36 (manufactured by UCB Corp.) and the like.

[0039] The optimal amount of photopolymerization initiator for curing the ultraviolet curable resin composition of the present invention is 0.01 to 10 mass%, particularly 0.5 to 7 in the total composition. Mass% is preferred. The upper limit of the compounding amount is preferable from the viewpoint of the curing characteristics of the composition, the mechanical and optical properties of the cured product, the handling amount, etc. The lower limit of the compounding amount is from this point of preventing the decrease in the curing rate. An enclosure is preferred.

 [0040] Examples of photosensitizers include triethylamine, jetylamine, N-methylethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid methyl, 4-dimethylaminobenzoic acid ethyl, 4-dimethylaminobenzoic acid. Isoamyl and the like can be mentioned, and as commercially available products, for example, Ubekryl P102, 103, 104, 105 (above, manufactured by UCB) and the like can be mentioned.

 [0041] When the ultraviolet curable resin composition of the present invention is cured, a thermal polymerization initiator may be used in combination as necessary. Preferred examples of the thermal polymerization initiator include peroxides and azo compounds. Specific examples include benzoyl peroxide, t-butyl peroxybenzoate, and azobisisobutyronitrile.

 [0042] In addition to the components described above, the ultraviolet curable resin composition of the present invention includes other oligomers that are curable within a range that does not impair the characteristics of the ultraviolet curable resin composition of the present invention, if necessary. Or a polymer can be mix | blended. Examples of other curable oligomers or polymers include polyurethane (meth) acrylates other than component (A), polyester (meth) acrylates, epoxy (meth) acrylates, polyamide (meth) acrylates, (meth) acrylates. Examples thereof include a siloxane polymer having a royloxy group, and a reactive polymer obtained by reacting a copolymer of glycidyl methacrylate and other polymerizable monomers with (meth) acrylic acid.

[0043] Further, in addition to the above components, various additives as necessary include, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents. Agents, surfactants, colorants, storage stabilizers, plasticizers, lubricants, mold release agents, solvents, fillers, anti-aging agents, wettability improvers and the like can be blended as necessary. Here, as the anti-oxidation simultaneous IJ, Irganoxl010, 1035, 1076, 1222 (or more Ruti'Chemicals Co., Ltd.), Antigen P, 3C, FR, GA-80 (Sumitomo Chemical Co., Ltd.) etc., etc., and UV absorption (for example, Tinuvin P, 234, 320, 326, 327, 328, 329, 213 (above, manufactured by Chino Spessianorety Chemikanoles Co., Ltd.), Seesorbl02, 103, 110, 501, 202, 712, 704 (above, manufactured by Siploi Co., Ltd.), etc. For example, Tinuvin 292, 144, 622LD (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), Sanol LS770 (Sankyo Co., Ltd.), Sumisorb TM_061 (Sumitomo Chemical Co., Ltd.) As the silane coupling agent, for example, _γ -aminopropyltriethoxysilane, _γ -mercaptopropyltrimethoxysilane, _γ -metaallyloxypropyltrimethoxysilane, commercially available products such as SH6062, 6030 (above, Toray Dowco Ning's (made by Silicone Co., Ltd.), KBE903, 603, 403 (made by Shin-Etsu Chemical Co., Ltd.), etc., and examples of the coating surface improver include silicone additives such as dimethylsiloxane polyether. Examples of commercially available products include DC-57, DC-190 (above, manufactured by Dowco), SH-28PA, SH-29PA, SH-30PA, SH-190 (above, Toray Dowco. Silicone Co., Ltd.), KF351, KF352, KF353, KF354 (above, Shin-Etsu Chemical Co., Ltd.), L—700, L—7002, L—7500, FK—024—90 (above, Nippon Tunica ( Etc.).

 [0044] The ultraviolet curable resin composition of the present invention can be produced by mixing the above-mentioned components by a conventional method. The viscosity of the ultraviolet curable resin composition of the present invention thus prepared is usually 200 to 50,000 mPa's / 25. C, preferably 1,500 to 10,000 mPa-s / 25 ° C. If the viscosity is too high, unevenness and undulation will occur in the production of the lens, and it will be difficult to obtain the target lens thickness, and the lens performance will not be fully demonstrated. On the other hand, if it is too low, it may not be possible to form a uniform lens with a constant thickness that makes it difficult to control the lens thickness.

[0045] A cured product obtained by curing the ultraviolet curable resin composition of the present invention has good restorability. Here, the recoverability of the cured product refers to, for example, a characteristic in which a trace of compression remaining on the lens surface disappears after a certain load is applied to the lens surface of the lens substrate peeled from the lens mold. Due to the good resilience, the contact marks caused by the load applied when the lenses are stacked and transported quickly disappear. If this contact mark remains, the image quality when set on TV is low. Invite the bottom, but the problem does not occur.

 The cured product obtained by curing the ultraviolet curable resin composition of the present invention has an Abbe number of 40 or more and a refractive index at 589 nm of 1.55 or more. Here, a large Abbe number means that the dispersibility of the refractive index is small, that is, the refractive index difference between the blue light and the red light with a small variation in the refractive index over the entire visible region. Means.

 [0047] In the present invention, the Abbe number is more preferably 42 or more, and 45 or more. Further, the refractive index difference between 436 nm (red light) and 589 nm (blue light) is preferably 0.015 or less, more preferably 0.010 or less.

 [0048] Because the refractive index at 589 nm is high, light on the red side (short-wavelength light) is refracted more than conventional organic resins, so no blue loss occurs on the TV screen. For example, rear projection TV It is possible to design a thinner thickness. In addition, even if the angle of the Fresnel lens is not made acute, blue spots do not occur, so that it is easy to manufacture the Fresnel lens.

 On the other hand, if the refractive index is less than 1.55, when a transmission screen is formed using the ultraviolet curable resin composition of the present invention, sufficient front luminance may not be secured.

 [0049] In order to obtain a cured product having a high Abbe number and a refractive index at 589 nm, it is effective to combine a high Abbe number and a high refractive index, and monomers (components (A) and (B)). is there. In addition to the above, it is effective to combine monomers having good viscosity characteristics and resilience in order to simultaneously provide coating properties (viscosity) and recoverability of the cured product.

[0050] The ultraviolet curable resin composition of the present invention is useful as a material for producing optical parts by having the above-mentioned advantageous characteristics.

 The ultraviolet curable resin composition of the present invention is a Fresnel lens material useful for designing a rear projection TV with a thinner thickness.

[0051] II. Rear Projection Engineering Fresnel Lens for TV

 The present invention optimizes the physical properties required for a rear projection TV Fresnel lens application of an ultraviolet curable resin composition.

As described above, the rear projection TV Fresnel lens of the present invention has a refractive index dispersion. Since the blue light has a low refractive index and the refractive index is high, no blue dropout occurs, so that the image quality is improved and a rear-projection TV with higher visibility can be configured.

[0052] [Example]

 EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

 [0053] Synthesis Example 1 of Urethane (Meth) Atalylate

2 A reaction vessel equipped with a stirrer, 4_ tolylene iso Xia sulphonate 16.72 wt%, Jirauri Rusanji n- butyltin 0.08 mass _^0/0, 2, 6-di -t-butyl-p Tarezoru 0. 02% by mass was charged and cooled to 5 to 10 ° C. Stirring temperature was added dropwise a 30 ° by Uni 2-hydroxy E chill Atari rate C is kept below 11.14 wt _^0/0 while. After completion of the dropwise addition, the mixture was reacted at 30 ° C for 1 hour. Next, 72.04% by mass of the diol described in the above formula (1) (all R ¹ and R ² are methyl groups, m + 1 = 22; average molecular weight = 1,500) was added at 50 to 70 ° C. The time response continued. The reaction was terminated when the residual isocyanate was 0.1% by mass or less. The urethane acrylate obtained by this method was designated as A-1.

 [0054] Synthetic example 2 of urethane (meth) acrylate

2 A reaction vessel equipped with a stirrer, 4-tolylene iso Xia sulphonate 35.47 wt%, Jirauri Rusanji n-butyltin 0.08 wt _^0/0, 2, 6-di t-butyl-p Tarezoru 0.02 weight % Was charged. While stirring, 23.65% by weight of 2-hydroxyethyl acrylate was added dropwise so that the temperature was kept below 30 ° C. After completion of the dropwise addition, the mixture was reacted at 30 ° C for 1 hour. Next, 40.77 wt% of bisphenol A ethylene oxide addition diol (total R ¹ and R ² are hydrogen, m + n = 2; average molecular weight = 320) is added, and the reaction is continued at 50 to 70 ° C. for 2 hours. It was. The reaction was terminated when the residual isocyanate was 0.1% by weight or less. The urethane acrylate obtained by this method was designated as A-2.

 [0055] Example 1

In a reaction vessel equipped with a stirrer, 37% by mass of A-1 as component (A), 11% by mass of phenoxyethoxyethyl acrylate as component (B), p-tamylphenoxyethylene glycol attaly rate 21 mass _^0/0, 14 mass Bulle force Puroratatamu _^0/0, tricyclodecane one 3, 8 - Jiiru dimethyl Atari rates 14 mass _^0/0, 1-hydroxy to single cycloalkyl as component (C) Xinolephenol-ketone was charged at a blending ratio of 3.0% by mass and stirred for 1 hour while controlling the liquid temperature at 50 to 60 ° C. to obtain a uniform liquid curable resin composition.

[0056] Examples 2 and 3 and Comparative Examples 1 and 2

 For Examples 2 and 3 and Comparative Examples 1 and 2, each component having the composition shown in Table 1 was charged into a reaction vessel to obtain each liquid curable resin composition.

<Measurement method and evaluation method of physical properties of cured product>

Using the liquid curable resin compositions obtained in the above Examples:! To 3 and Comparative Examples 1 and 2, a test piece (cured product) was prepared by the following method, and the refractive index (n ²⁵ ) was as follows: , Abbe number, coatability

 D

 (Viscosity) and restorability were measured. The results are shown in Table 1 below.

[0058] The Abbe number, refractive index (n ²⁵ ), viscosity, and restorability of each monomer of component (A) and component (B) used in each example and comparative example were similarly measured or evaluated. The results are shown in Table 1 below.

 D

 Show.

 [0059] (1) Refractive index (n measurement: applicator bar so that the film thickness is 200 x m on the glass plate.

 D

The resin composition was applied using 1. and irradiated with ultraviolet rays of Oj / cm ² under nitrogen to prepare a test piece. In accordance with JIS K7105, the refractive index at 25 ° C was measured using an Abbe refractometer manufactured by Atago Co., Ltd.

Note that the refractive index (n ²⁵ ) of component (A) and component (B) is determined as 1.

 D

 1. △ is over 54 and 1. 55 or less is “△”, 1. 55 is over 1. 56 is under “○”, 1. over 56 is “◎”.

[0060] (2) Abbe number measurement:

 The refractive power of D-line (589 nm), F-line (486 nm), and C-line (656 nm) was calculated using a multi-wavelength Abbe refractometer manufactured by Atago Co., Ltd.

 The Abbe number of component (A) and component (B) is determined as “X” when less than 40, “◯” when exceeding 40 and less than 50, and “◎” when exceeding 50 and less than 60. "," Exceeding 60 was rated as "◎◎".

 [0061] (3) Coating property (viscosity):

 The sample was kept at 25 ° C and measured according to JIS K-7117 using a B-type viscometer.

When the viscosity at 25 ° C exceeds 4000 mPas, “○”, and when the viscosity is 4000 mPas or less, X ”.

 [0062] (4) Restorability: A ball remaining on the lens surface after pressing a 0.4 mm φ metal ball indenter with a 30 g load for 1 minute on the lens surface of the lens substrate peeled off from the lens mold described above. The trace disappearance time was measured. At this time, “○” indicates that the ball mark is strong or disappears within 30 minutes, “△” indicates that the ball mark disappears within 30 minutes or more, and over 1 hour. Even if the ball mark did not disappear, “X” was assigned.

[0063] [Table 1]

table 1

 Characteristic of raw material alone Composition of 8 curable trees

 Component Target A Number Judgment “D Judgment Viscosity Restoration Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Urethane Atylate Oligomer (A-1) 36.8 X 1.54 Δ

 (A) o ○ 37 30 34 31

 Urethane acrylate oligomer (A—2) 36.7 X 1.58 © ○ Δ 4

 Phenoxetyl Atariate 35.0 X 1.57 ◎ X ◎ 11 9 10 29 8

 Single Paracumyl Noxyethylene glycol Atari 1 / t 32.9 X 1.58 © X ◎ 21 17 21

 Official

 Vinyl caprolactam

 No 47.1 ο 1.54 Δ X Δ 14 13 13

 Acryloylmorpholine 44.4 ο 1.55 〇 X Δ 13

 Tetrabromobisphenol A epoxy acrylate 34.0 X 1.56 © X 9 4 8

 E0 modified bisphenol A diacrylate 35.1 X 1.57 9

 (B) ◎ △ X

 Tricyclodecane 1,8-diyldimethyldiatalylate 62.0 © ◎ 1.53 X Δ Δ 14 10 15 17 21

 Multi-nonanediol glue 57.7

 Government ◎ 1.50 X X ○ 13

 No Tetrabromobisphenol A Epoxy acrylate 34.1 X 1.59 ◎ ◎ X X 20

 Tris (acrylochichetil) isocyanurate 53.0 ◎ 1.53 X Δ Δ 9 14

 Trimeti D-Loop α Pant Reacriate 45.7 ○ 1.51 X X X 3

 Dipentaerythritol hexahexarate 51.3 ◎ 1.50 X X X X 4

 (C) 1-Hydroxy-SiC ο-Hexyl-Fuylketone 3 3 3 3 3

 Total 100 too 100 100 100

 Characterization of cured product

Refractive index (n ⁵ ) 1 1.55 1.55 1.55 1.55 1.54 1.55 or more Appe number------42 46 42 38 48 40 or more Coating property (viscosity) OO 〇 X 〇 Restorability of cured product 〇 〇 OXX 〇

[0064] In Table 1,

 (B) component:

 Phenoxetyl Atylate: New Frontier PHE p-cumino phenoxyethylene glycol acrylate (D-cumyl phenol acrylate modified with 1 mol of ethylene oxide), manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Made by Toagosei Co., Ltd., Alonics Ml 10 Vininole Power Prolatatum: Made by BASF

 Atariloyl morpholine: manufactured by Kojin Co., Ltd., ACMO

 Tetrabromobisphenol A epoxy acrylate: Showa Polymer Co., Ltd., VR77 EO-modified bisphenol A diathalate: Osaka Organic Chemical Industry Co., Ltd., Biscoat 700 Tricyclodecane-3,8-diyldimethyldiatalate: Mitsubishi Chemical Co., Ltd., Upima UV SA1002

 Nonanediol ditalylate: Daiichi Kogyo Seiyaku Co., Ltd., New Frontier LA-9A Tetrabromobisphenol A Epoxy Atallate: Nippon Pica Co., Ltd. Neoponole V779

 Tris (2-ataryllooxychetyl) isocyanurate: Toagosei Co., Ltd., ALONIX M315

 Trimethylolpropane tritalylate: Osaka Organic Chemical Industry Co., Ltd., Biscoat 295 Dipentaerythritol Hexaatalylate: Nippon Kayaku Co., Ltd., DPHA

[0065] Component (C):

 1-Hydroxy 1-cyclohexyl 1-phenyl 1-ketone: Ciba 'Specialty' Chemicals Co., Ltd., Irgacure 1

 Industrial applicability

[0066] The ultraviolet curable resin composition of the present invention has a high refractive index (n ²⁵ ) and excellent adhesion to a substrate.

 D

 Therefore, it is suitable for the production of optical members such as lens sheets.

[0067] The cured product obtained by curing the ultraviolet curable resin composition of the present invention has a high Abbe number and a high refractive index at 589 nm. Therefore, the dispersibility of the refractive index depending on the wavelength is small, and particularly a thin rear projection. Conventional organic resin when used as a Fresnel lens for TV The blue color which is a problem with the lens made of is not generated, and good image quality is provided.

Claims

The scope of the claims

 [1] The following components (A), (B) and (C):

 (A) (a) hydroxyl group-containing (meth) acrylate and (b) organic polyisocyanate are reacted, then (c) formula (1)

 [Chemical 6]

(Wherein, R ¹ represents a hydrogen atom, a methyl group, or Echiru group, Yogu even if Mashimashi these mixed to R ¹ in one molecule, however, R ¹ of at least 50 mol% of all R ¹ R ² represents a hydrogen atom or a methyl group, and m and n each represents a number of 1 to 20). Atarirate;

 (B) an ethylenically unsaturated group-containing compound other than the component (A);

 (C) Photopolymerization initiator

And a cured product obtained by curing the same has an Abbe number of 0 or more and a refractive index (n ²⁵ ) at 589 nm of 1.55 or more.

 D

 An ultraviolet curable resin composition.

[2] The ultraviolet curable resin composition according to claim 1, wherein the average value of the Abbe number of the component (B) is 41 or more.

 [3] The ultraviolet curable resin composition according to claim 1, wherein the molecular weight of component (A) is 350 or more.

4. The ultraviolet curable resin composition according to any one of claims 1 to 3, which is used for forming an optical member.

 [5] Any one of claims 1 to 4, comprising a cured product of the ultraviolet curable resin composition according to item 1.