JP2008081737A - Active energy ray-curable resin composition for optical sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active energy ray-curable resin composition for an optical sheet which gives a cured material excellent in dimensional stability and optical transparency. <P>SOLUTION: The active energy ray-curable resin composition for the optical sheet comprises a copolymer (A) which makes an ethylenically unsaturated monomer (a1) whose homopolymer has a glass transition temperature of 80-250°C as a constitutional unit and has at least one (meth)acryloyl group, a polymerization initiator (B), and a multifunctional (meth)acrylate which has 3-6 acryloyl groups (C). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an active energy ray-curable resin composition for optical sheets. More specifically, the present invention relates to an active energy ray-curable resin composition for optical sheets, which gives a cured product excellent in dimensional stability and light transmittance.

  Optical sheet such as prism sheet for improving brightness of liquid crystal display device, light diffusing sheet, Fresnel lens for projection TV, lenticular lens, etc., active energy ray curable resin (urethane acrylate etc.) composition and resin for the purpose of improving productivity [For example, a polyethylene terephthalate (hereinafter abbreviated as PET), polycarbonate, polystyrene] sheet is used, which is continuously produced by shaping with a mold and curing with ultraviolet rays (see, for example, Patent Document 1). .

JP 2003-107219 A

  However, in this method, since the lamp as a light source generates heat simultaneously with light emission, the optical sheet in the vicinity of the lamp is exposed to a temperature of about 80 ° C., and is partially bent and deformed. There is a problem that luminance unevenness occurs and a problem that under high humidity, dimensional stability is deteriorated due to moisture absorption of the optical sheet, and deformation due to bending is promoted.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention comprises a copolymer (A) having at least one (meth) acryloyl group having a structural unit of an ethylenically unsaturated monomer (a1) having a glass transition temperature of 80 to 250 ° C. of the homopolymer, An active energy ray-curable resin composition for an optical sheet, comprising a polymerization initiator (B) and a polyfunctional (meth) acrylate (C) having 3 to 6 (meth) acryloyl groups; A cured product obtained by curing; an optical sheet having the cured product on at least a part of at least one side of the substrate; and applying the composition to at least a part of at least one side of the substrate and irradiating with active energy rays. It is a manufacturing method of the optical sheet characterized by making it harden.

The active energy ray-curable resin composition of the present invention has the following effects.
(1) A cured product obtained by curing the composition is excellent in dimensional stability.
(2) A cured product obtained by curing the composition is excellent in light transmittance.

The active energy ray-curable resin composition for an optical sheet of the present invention has an ethylene whose homopolymer has a glass transition temperature (hereinafter abbreviated as Tg) of 80 to 250 (preferably 85 to 200, more preferably 90 to 180) ° C. Polyfunctional having a copolymerizable monomer (a1) as a constituent unit and at least one (meth) acryloyl group copolymer (A), polymerization initiator (B), and 3 to 6 (meth) acryloyl groups It consists of (meth) acrylate (C).
When the Tg of the homopolymer (a1) is less than 80 ° C., the dimensional stability of the cured product described later is deteriorated, and when it exceeds 250 ° C., the flexibility of the cured product is deteriorated.
When the number of (C) (meth) acryloyl groups in (C) is less than 3, the hardness of the cured product decreases, and when it exceeds 6, warpage due to shrinkage of the cured product is deteriorated.

  (A1) includes 2 to 40 carbon atoms (hereinafter abbreviated as C), for example, an aromatic ring-containing vinyl compound (a11), a cyclic olefin (a12), a halogen-containing aliphatic vinyl compound (a13), and a cyano group-containing aliphatic vinyl. The compound (a14), the (meth) acryloyl group-containing compound (a15) and a mixture thereof are included.

The aromatic ring-containing vinyl compound (a11) includes monocyclic [C8-40, such as styrene, alkyl (C1-36) styrene (o-, m- and p-methylstyrene, α- and β-methylstyrene, p- t-butylstyrene, etc.), o-, m- and p-chlorostyrene, pt-butoxystyrene, dimethylaminomethylstyrene, dimethylaminoethylstyrene] and polycyclic [C12-40, such as vinylnaphthalene, 4-methylthio −1-vinylnaphthalene, 1- (3-naphth-1-ylthio) propylthio-4-vinylnaphthalene, N-vinylcarbazole] compound.
Among these, styrene, α- and β-methylstyrene, pt-butylstyrene, o-, m- and p-chlorostyrene are preferable from the viewpoint of light transmittance and dimensional stability of the cured product described later. is there.

  The cyclic olefin (a12) includes a non-aromatic cyclic hydrocarbon having 5 to 30 carbon atoms and having an ethylenically unsaturated bond in the ring structure and / or outside the ring, and each of the following general formulas (1) to (4): And [(a121), (a122), (a123) and (a124)].

［式中、複数のＲ¹は同一でも異なっていてもよい、ＨまたはＣ１〜４のアルキル基；複数のＲ²は同一でも異なっていてもよい、Ｈ、Ｃ１〜１２の炭化水素基、カルボキシル基、−ＣＯＯＲ⁴基（但し、Ｒ⁴はＣ１〜４のアルキル基）、ハロゲン原子、シアノ基、ベンゾイル基；Ｒ³はＨまたは、Ｒ²と結合して環を形成してなるアルキリデンもしくはアルケニリデン基；ｈは０〜２の整数を表し、繰り返し単位の６員環内には二重結合を有していてもよい。］

[Wherein a plurality of R ^{1 s} may be the same or different, H or a C1-4 alkyl group; a plurality of R ^{2 s} may be the same or different, H, a C1-12 hydrocarbon group, carboxyl Group, —COOR ⁴ group (where R ⁴ is a C1-4 alkyl group), halogen atom, cyano group, benzoyl group; R ³ is H or alkylidene or alkenylidene formed by bonding to R ² to form a ring Group; h represents an integer of 0 to 2, and a 6-membered ring of the repeating unit may have a double bond. ]

［（２）〜（４）式中、Ｒ1およびｈは上記に同じ。一般式（２）、（３）における繰り返し単位の６員環内には二重結合を有していてもよい。］

[In the formulas (2) to (4), R1 and h are the same as above. The 6-membered ring of the repeating unit in formulas (2) and (3) may have a double bond. ]

Examples of the alkyl group in R ¹ include methyl, ethyl, n- and i-propyl and n-, i-, sec- and t-butyl groups.
Among R ¹ , H, methyl group and ethyl group are preferable from the viewpoint of dimensional stability.
The hydrocarbon group in R ² includes an aliphatic group [alkyl group (C1-4, such as methyl, ethyl, n- and i-propyl and n-, i-, sec- and t-butyl groups), alkenyl (C2-5, such as ethenyl, propenyl, butenyl, pentenyl), (in the case where R ² and R ³ are bonded to form a ring, C2-5, for example ethylidene, propylidene and butylidene) alkylidene group, alkenylidene A group (when R ² and R ³ are combined to form a ring, C2-5, such as vinylidene, propenylidene, and butenylidene), etc.], an alicyclic group (C4-6, such as cyclobutyl, cyclohexyl, and cyclohexenyl) And aromatic groups (C6-12, such as phenyl and naphthyl groups).
Among R ² , H, methyl group, ethyl group, ethylidene group and vinylidene group are preferable from the viewpoint of heat resistance. h is preferably 0 or 1 from the viewpoint of the mechanical strength (tensile strength, tensile elongation, etc.) of the cured product.

Specific examples of (a121) include 2-norbornene, 1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 5-ethylidene-2-norbornene , 5-vinyl-2-norbornene and 2-ethylidene-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and the like.
Of these, 2-ethylidene-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a is preferable from the viewpoint of light transmittance and dimensional stability of the cured product. -Octahydronaphthalene and more preferred 2-norbornene, 1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and 5-ethylidene-2-norbornene It is.

  Examples of (a122) include tetrahydroindene, hexahydroindene, 1-methylindene and the like. Among these, tetrahydroindene and hexahydroindene are preferable from the viewpoint of light transmittance and dimensional stability of the cured product.

  Examples of (a123) include dicyclo-, tricyclo-, and tetracyclopentadiene. Among these, dicyclo- and tricyclopentadiene are preferable from the viewpoint of light transmittance and dimensional stability of the cured product.

  Examples of (a124) include norbornadiene and 2,5-norbornadiene. Among these, norbornadiene is preferable from the viewpoint of light transmittance and dimensional stability of the cured product.

  The halogen-containing aliphatic vinyl compound (a13) includes C2 to 10, for example, 1,2-difluoroethylene, tetrafluoroethylene, tetradecafluoropentylethylene, hexafluoropropylene, and the light transmittance and dimensional stability of the cured product. From the viewpoint of properties, tetradecafluoropentylethylene is preferred.

  The cyano group-containing aliphatic vinyl compound (a14) contains C3-10, such as acrylonitrile and 1-acetoxy-1-cyanoethylene, and 1- is preferred from the viewpoint of light transmittance and dimensional stability of the cured product. Acetoxy-1-cyanoethylene.

In the (meth) acryloyl group-containing compound (a15), the number (functionality) of (meth) acryloyl groups is 1-2, and C8-40 aromatic ring-containing (meth) acrylate (a151), alicyclic ring-containing ( A meth) acrylate (a152), a cyano group-containing (meth) acrylate (a153), a halogen-containing (meth) acrylate (a154) and a (meth) acrylamide compound (a155) are included.
Among these, (a152) and (a154) are preferable from the viewpoint of light transmittance and dimensional stability of the cured product.

  The aromatic ring-containing (meth) acrylate (a151) includes bifunctional [alkylene oxide of bisphenol A (hereinafter abbreviated as AO) adduct, etc.], monofunctional [naphthyl (meth) acrylic acid, anthranyl (meth) ) Acrylic acid etc.] are included, and from the viewpoint of light transmittance and dimensional stability of the cured product, the bifunctional (A) adduct (meth) acrylate of bisphenol A is preferred, and the anthranyl (meth) acrylic acid is monofunctional It is.

  Bicyclic [dicyclopentadienyl di (meth) acrylate, etc.], monofunctional [isobornyl (meth) acrylate, adamantyl (meth) acrylate, 3,5-dimethyladamantyl] (Meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, etc.] and the like, and dicyclopentadienyl di (meth) is preferred from the viewpoint of light transmittance and dimensional stability of the cured product. An acrylate, monofunctional is isobornyl (meth) acrylate.

  The cyano group-containing (meth) acrylate (a153) includes monofunctional [cyanomethyl-, 2-cyanoethyl-, 2-cyanobutyl-, 2-cyanohexyl-, 2-cyanoheptyl (meth) acrylate, etc.] and the like. From the viewpoint of light transmittance and dimensional stability of the cured product, cyanomethyl (meth) acrylate is preferred.

  The halogen-containing (meth) acrylate (a154) includes monofunctional [monofluoromethyl-, difluoromethyl-, trifluoromethyl-, pentafluoroethyl-, trichloromethyl (meth) acrylate, etc.] and the like. From the viewpoint of light transmittance and dimensional stability, trifluoromethyl (meth) acrylate is preferred.

  The (meth) acrylamide compound (a155) contains monofunctional [(meth) acrylamide, N-sec- or N-tert-butyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl and -diisopropyl. (Meth) acrylamide, N- (meth) acryl morpholide, N- (meth) acryl piperidide, etc.] and the like, and from the viewpoint of light transmittance and dimensional stability of the cured product, N- (Meth) acryl morpholide, more preferably N-acryl morpholide.

  The monomer constituting the copolymer (A) in the present invention further has an ethylenically unsaturated monomer other than (a1), which has a functional group reactive with the hydroxyl group-containing (meth) acrylates (a2) and (a2). At least one monomer selected from the group consisting of (a3) may be added. Moreover, the (meth) acryloyl group in (A) may be derived from any of (a1) to (a3).

  (A2) includes C4-30, such as 2-hydroxyethyl-, hydroxypropyl- and hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, caprolactone-modified (meth) acrylate [e.g. (Poly) caprolactone (reaction product of n = 1-5) and 2-hydroxyethyl (meth) acrylate] is included, and hydroxyethyl (meth) acrylate is preferred from the viewpoint of high hardness of the cured product surface.

  (A3) includes carboxyl group-containing (meth) acryloyl group-containing compound (a31), epoxy group-containing (meth) acrylate (a32), isocyanate group-containing (meth) acrylate (a33), (meth) acrylic acid and (meth) ) (Anhydrous) unsaturated carboxylic acids (a34) which do not contain acryloyl groups.

  (A31) includes C5 to 20, for example, 2- (meth) acryloyloxyethyl-succinic acid, -hexahydrophthalic acid, and -phthalic acid. From the viewpoint of the surface hardness of the cured product, 2- (meth) is preferable. (Meth) acryloyloxyethyl succinic acid.

  (A32) includes C6-20, for example, glycidyl (meth) acrylate, α-ethyl-, α-n-propyl- and glycidyl α-n-butyl acrylate, (meth) acrylic acid-3,4-epoxy. Dimension of cured product including butyl, (meth) acrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6,7-epoxyheptyl, o-, m- and p-vinylbenzylglycidyl ether Preferred from the viewpoints of stability and surface hardness are glycidyl methacrylate, methacrylic acid-6,7-epoxyheptyl, o-, m- and p-vinylbenzyl glycidyl ether.

  (A33) includes C6-20, for example, bifunctional [bis (meth) acryloyl isocyanate, etc.], monofunctional [2- (meth) acryloyloxyethyl isocyanate, etc.], and is preferable from the viewpoint of reactivity. Bis (meth) acryloyl isocyanate.

  (A34) includes C4 to C20, such as (anhydrous) fumaric acid, (anhydrous) itaconic acid and (anhydrous) maleic acid, oleic acid, linoleic acid, linolenic acid, and is preferable from the viewpoint of the surface hardness of the cured product. Is maleic anhydride.

The proportion of the structural unit (a1) based on the weight of (A) is usually from 30 to 90%, preferably from 35 to 85%, more preferably from 40 to 83%, particularly preferably from the viewpoint of dimensional stability and the hardness of the cured product. 50-80%
The proportion of (a2) is usually 30% or less, preferably 26% or less, more preferably 5 to 15% from the viewpoint of the hardness of the cured product and curling of the cured product; more preferably 5 to 15%; the proportion of (a3) is usually 40% Hereinafter, it is preferably 10 to 30% from the viewpoint of the hardness of the cured product and the suppression of warpage of the cured product.
Among the combinations of (a1), (a2), and (a3), the combination of (a1) / (a2) / (a3) is preferable from the viewpoint of dimensional stability, and the weight ratio is the hardness of the cured product. From the viewpoint, it is preferably 40 to 70/10 to 30/20 to 30.

  The ratio of (A) based on the total weight of (A) and (B) and (C) described later is preferably 50 to 97%, more preferably 55 to 90% from the viewpoint of dimensional stability and hardness of the cured product. It is.

The polymerization initiator (B) includes a photopolymerization initiator (B1), a thermal polymerization initiator (B2), and a mixture thereof.
Examples of (B1) include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoylformate compounds (methylbenzoyl formate, etc.) ), Thioxanthone compounds (such as isopropyl thioxanthone), benzophenone compounds (such as benzophenone), phosphate ester compounds (such as 1,3,5-trimethylbenzoyldiphenylphosphine oxide), benzyldimethyl ketal, and the like.
Among these, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and 1,3,5-trimethylbenzoyldiphenylphosphine oxide are preferable from the viewpoint of preventing coloring of the cured product. is there.

  Examples of (B2) include peroxides (t-butyl peroxybenzoate, benzoyl peroxide, methyl ethyl ketone peroxide, etc.) and azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.). Of these, peroxides are preferable from the viewpoint of stability and reactivity of the composition, and t-butyl peroxybenzoate and methyl ethyl ketone peroxide are more preferable.

  The amount of (B) used is preferably from 0.1 to 20%, more preferably from the viewpoint of reactivity and hardness of the cured product, based on the total weight of (A), (B) and (C) described later. 0.3 to 10%.

  The polyfunctional (meth) acrylate (C) having 3 to 6 (meth) acryloyl groups is C14 or more and a number average molecular weight [hereinafter abbreviated as Mn. The measurement is based on a gel permeation chromatography (GPC) method. ] 1,000 or less, for example, pentaerythritol (hereinafter abbreviated as PE) tri- and tetra (meth) acrylate, trimethylolpropane (hereinafter abbreviated as TMP) triacrylate, dipentaerythritol (hereinafter abbreviated as DPE) hexa (meth) acrylate Glycerol (hereinafter abbreviated as GR) AO adduct tri (meth) acrylate, PE AO adduct tri- and tetra (meth) acrylate, and the like. Among these, PE tri (meth) acrylate and DPE hexa (meth) acrylate are preferable from the viewpoint of the surface hardness of the cured product.

  The amount of (C) used is preferably 2.9 to 49.9% based on the total weight of (A), (B) and (C) from the viewpoint of hardness of the cured product and curling of the cured product. More preferably, it is 5 to 40%, and particularly preferably 10 to 30%.

If necessary, the composition of the present invention may further contain various other additives (D) used for paints and inks as long as the effects of the present invention are not impaired. (D) includes inorganic fine particles (D1), organic fine particles (D2), organic pigments (D3), dispersants (D4), antifoaming agents (D5), leveling agents (D6), and silane coupling agents (D7). , Thixotropic property-imparting agent (thickening agent) (D8), slip agent (D9), antioxidant (D10) ultraviolet absorber (D11) and antistatic agent (D12).
The total use amount of (D) is usually 60% or less based on the total weight of the composition of the present invention, preferably 0.5 to 50% from the viewpoint of the addition effect and industrial viewpoint.

  Examples of the inorganic fine particles (D1) include alumina [aluminum oxide, aluminum hydroxide, alumina white (alumina hydrate), silica alumina (a fused product of alumina and silica, alumina surface coated with silica, etc.)], zirconia , Tungsten carbide, titanium carbide, silicon carbide, boron carbide, diamond, carbon black (channel black, furnace black, thermal black, acetylene black, etc.), silica (fine powdered silicic acid, hydrous silicic acid, diatom, colloidal silica, etc.), Silicate (fine magnesium silicate, talc, soapstone, stearite, calcium silicate, magnesium aluminosilicate, sodium aluminosilicate, etc.), carbonate (sedimentation (active, dry, heavy or light) calcium carbonate, carbonic acid Magnesium Etc.], clay (kaolinic clay, sericite clay, vilophyllite clay, montmorillonite clay, bentonite, acid clay, etc.), sulfate [aluminum sulfate (sulfate band, satin white, etc.), barium sulfate (barite powder) , Precipitated barium sulfate, lithopone, etc.), magnesium sulfate, calcium sulfate (stone koji) (anhydrous koji, hemihydrate koji, etc.)], lead white, mica powder, zinc white, titanium oxide, activated calcium fluoride, cement Lime, calcium sulfite, molybdenum disulfide, asbestos, glass fiber, lock fiber, microballoon and the like.

Of these, from the viewpoint of scratch resistance and composition of the cured product (film), and suppression of coloring of the cured product, alumina, silica, silicate, carbonate, sulfate, and titanium oxide are preferable, and silica is more preferable. Calcium carbonate, barium sulfate and titanium oxide.
(D1) may be used in combination of two or more, or two or more may be combined (for example, titanium oxide is fused to silica). The shape of (D1) is not particularly limited, and may be, for example, an indefinite shape, a spherical shape, a hollow shape, a porous shape, a petal shape, an aggregated shape, or a granular shape.
The amount of (D1) used is usually 50% or less based on the total weight of the composition of the present invention, preferably from 5 to 30%, more preferably from 10 to 25 from the viewpoint of heat resistance and flexibility of the cured product. %.

Examples of the organic fine particles (D2) include beads of acrylic, styrene, silicone, polyurethane, acrylic urethane, benzoguanamine, and polyethylene resins. Of these, silicone resin beads are preferred from the viewpoint of heat resistance.
Moreover, the number average particle diameter (μm) of (D2) is preferably 1 to 30, more preferably 3 to 20, from the viewpoints of light transmittance and coatability of the cured product.
The amount of (D2) used is usually 50% or less based on the total weight of the composition of the present invention, preferably 5 to 40%, more preferably 10 to 35, from the viewpoints of heat resistance and coating properties of the cured product. %.

Examples of the organic pigment (D3) include the following (1) to (4).
(1) Azo pigments Insoluble monoazo pigments (toluidine red, permanent carmine FB, fast yellow G, etc.), insoluble disazo pigments (disazo yellow AAA, disazo orange PMP, etc.), azo lakes (soluble azo pigments) (lake red C, brilliant carmine 6B) Etc.), condensed azo pigments, chelate azo pigments, etc .;
(2) Polycyclic pigments: phthalocyanine blue, indanthrone blue, quinacridone red, dioxazine violet, etc .;
(3) Dyeing lakes Basic dyes (Victoria Pure Blue BO lake, etc.), acidic dyes (alkali blue toner, etc.), etc .;
(4) Others Azine pigments (aniline black, etc.), daylight fluorescent pigments, nitroso pigments, nitro pigments, natural pigments, etc.
The amount of (D3) used is usually 5% or less based on the total weight of the composition of the present invention, preferably 0.5 to 4%, more preferably 1 from the viewpoint of colorability and flexibility of the cured product. ~ 3%.

  Examples of (D4) include organic dispersants [polymer dispersants (Mn 2,000 to 500,000) and low molecular dispersants (molecular weight of 100 or more and less than Mn 2,000)] and inorganic dispersants.

  Examples of the polymer dispersant include naphthalene sulfonate [alkali metal (lithium, sodium, potassium, etc.) salt, quaternary ammonium salt, and the following salts. ] Formalin condensate, polystyrene sulfonate, polyacrylate, poly (2-4) carboxylic acid (maleic acid / glycerin / monoallyl ether copolymer, etc.) salt, carboxymethyl cellulose (Mn 1,000-10,000) ) And polyvinyl alcohol (Mn 1,000 to 100,000).

Examples of the low molecular weight dispersant include the following (1) to (8).
(1) Polyoxyalkylene type AO [C2-4, aliphatic alcohol (C4-30), [alkyl (C1-30)] phenol, aliphatic (C4-30) amine and aliphatic (C4-30) amide For example, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO)] 1 to 30 mol adduct, etc .;
N-, i-, sec- and t-butanol, octanol, dodecanol and the like as the aliphatic alcohol; phenol, methylphenol and nonylphenol as the (alkyl) phenol; laurylamine and methylstearyl as the aliphatic amine Examples of the aliphatic amides include stearic acid amides.
(2) Polyhydric alcohol type C4-30 fatty acid (lauric acid, stearic acid, etc.) and polyhydric (divalent to hexavalent or higher) alcohol [for example, glycerin, pentaerythritol, sorbitol (hereinafter referred to as GR, PE, SO respectively) Abbreviation) and sorbitan] monoester compounds, etc .;
(3) Carboxylate type C4-30 fatty acid (same as above) alkali metal (same as above) salt and the like;
(4) Sulfate ester type C4-30 aliphatic alcohol (same as above) and sulfate alcohol alkali metal (same as above) salts of aliphatic alcohol AO (C2-4) 1-30 mol adduct, etc .;

(5) Sulfonate type [Alkyl (C1-30)] Phenol (same as above) sulfonate alkali metal (same as above) salt and the like;
(6) Phosphate ester type C4-30 fatty alcohol (same as above) and aliphatic alcohol AO (C2-4) 1-30 mol adduct mono or diphosphate salt [alkali metal The same) salt, quaternary ammonium salt, etc.];
(7) Primary to tertiary amine salt type C4-30 aliphatic amine [primary amine (such as laurylamine), secondary amine (such as dibutylamine) and tertiary amine (such as dimethylstearylamine)] hydrochloride, tri Inorganic acid (hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.) salt of monoester of ethanolamine and C4-30 fatty acid (same as above);
(8) Quaternary ammonium salt type Inorganic acid (same as above) salts of C4-30 quaternary ammonium (butyltrimethylammonium, diethyllaurylmethylammonium, dimethyldistearylammonium, etc.).

Examples of the inorganic dispersant include alkali metal (same as above) salts of polyphosphoric acid and phosphoric acid-based dispersants (phosphoric acid, monoalkyl phosphoric acid ester, dialkyl phosphoric acid ester and the like).
The amount of (D4) used is preferably 5% or less based on the total weight of the composition of the present invention, and preferably 0 from the viewpoints of dispersibility such as (D1) to (D3) and the flexibility of the cured product. 0.05-3%.

Antifoaming agents (D5) include lower alcohols (C1-6) (methanol, butanol, etc.), higher alcohols (C8-18) (octyl alcohol, hexadecyl alcohol, etc.), higher fatty acids (C10-20) (oleic acid) , Stearic acid, etc.), higher fatty acid esters (C11-30) (glycerin monolaurate, etc.), phosphate esters (tributyl phosphate, etc.), metal soaps (calcium stearate, aluminum stearate, etc.), polyether [polyethylene glycol (hereinafter referred to as “polyethylene glycol”) PEG (abbreviated) (Mn200 to 10,000), polypropylene glycol (hereinafter abbreviated as PPG) (Mn200 to 10,000), etc.], silicone (dimethylsilicone oil, alkyl-modified silicone oil, fluorosilicone oil, etc.) and mineral oils Silica powder those dispersed in mineral oil) and the like.
The amount of (D5) used is usually 3% or less based on the total weight of the composition of the present invention, and preferably 0.01 to from the viewpoint of defoaming properties during production of the cured product and light transmittance of the cured product. 2%.

As the leveling agent (D6), PEG type nonionic surfactant (nonylphenol EO 1 to 40 mol adduct, stearic acid EO 1 to 40 mol adduct, etc.), polyhydric alcohol type nonionic surfactant (sorbitan palmitic acid monoester) Sorbitan stearic acid monoester, sorbitan stearic acid triester, etc.), fluorine-containing surfactant (perfluoroalkyl EO 1-50 mol adduct, perfluoroalkyl carboxylate, perfluoroalkyl betaine, etc.), modified silicone oil [above Other than (D5), for example, polyether-modified silicone oil and (meth) acrylate-modified silicone oil].
The amount of (D6) used is usually 3% or less based on the total weight of the composition of the present invention, preferably from 0.1 to 2 in terms of leveling properties during coating of the composition and light transmittance of the cured product. %.

Examples of the silane coupling agent (D7) include amino group-containing silane coupling agents (γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-phenylaminopropyl trimethoxysilane, etc.), ureido group-containing silane. Coupling agents (ureidopropyltriethoxysilane, etc.), vinyl group-containing silane coupling agents [vinylethoxysilane, vinylmethoxysilane, vinyltris (β-methoxyethoxy) silane, etc.], (meth) acrylate group-containing silane coupling agents [ γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, etc.], epoxy group-containing silane coupling agent (γ-glycidoxypropyltrimethoxysilane, etc.), isocyanate group-containing silane Coupling agent (γ-isocyanatopropyltriethoxysilane, etc.), polymer type silane coupling agent (polyethoxydimethylsiloxane, polyethoxydimethylsiloxane, etc.), cationic type silane coupling agent [N- (N-benzyl-β-aminoethyl) ) -Γ-aminopropyltrimethoxysilane hydrochloride, etc.].
The amount of (D7) used is usually 5% or less based on the total weight of the composition of the present invention, preferably 0.5 to 3% from the viewpoint of adhesion of the cured product to the substrate and light transmittance. is there.

Thixotropy imparting agent (thickener) (D8) includes inorganic thixotropic imparting agents [bentonite, organically treated bentonite (surface wax coating treated bentonite, etc.) and ultrafine surface treated calcium carbonate (colloidal calcium carbonate, etc.)] and Examples include organic thixotropic property-imparting agents (hydrogenated castor oil wax, calcium stearate, aluminum oleate, polymerized linseed oil, etc.).
The amount of (D8) used is usually 10% or less based on the total weight of the composition of the present invention, preferably from the viewpoint of dispersibility such as (D1) to (D3) and the flexibility of the cured product. 5 to 5%.

As the slip agent (D9), higher fatty acid esters (C11-30, such as butyl stearate), higher fatty acids (C10-20, such as oleic acid, stearic acid) amide (ethylene bis-stearic acid amide, oleic acid amide, etc.), Metal soap (calcium stearate, aluminum oleate, etc.), wax [paraffin wax, polyolefin wax (polyethylene wax, polypropylene wax, carboxyl group-containing polyethylene wax, etc.)] and silicone (eg dimethyl silicone oil, alkyl-modified silicone oil and fluorosilicone) Oil).
The amount of (D9) used is usually 5% or less based on the total weight of the composition of the present invention, preferably 0.01 from the viewpoint of blocking resistance of composition components such as fine particles and light transmittance of the cured product. ~ 2%.

Antioxidants (D10) include hindered phenol compounds [triethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis. [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,5-di- t-butyl-4-hydroxybenzylphosphonate diethyl ester] and amine compounds (n-butylamine, triethylamine, diethylaminomethyl methacrylate, etc.).
The amount of (D10) used is usually 3% or less based on the total weight of the composition of the present invention, and preferably 0.005 to 2% from the viewpoint of the antioxidant effect and low colorability.

As the ultraviolet absorber (D11), a benzotriazole compound [2- (5-methyl-2
-Hydroxyphenyl) benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chloro Benzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, etc.], triazine compound [2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol], benzophenone (2-hydroxy-4-n-octyloxybenzophenone, etc.), oxalic acid anilide compound (2-ethoxy-2'-ethyloxalic acid bisanilide, etc.) It is done.
The amount of (D11) used is usually 3% or less based on the total weight of the composition of the present invention, and preferably 0.005 to 2% from the viewpoint of weather resistance and light transmittance.

  Examples of the antistatic agent (D12) include a cationic antistatic agent (D121), an anionic antistatic agent (D122), and a nonionic antistatic agent (D123).

Examples of (D121) include amidinium salts, guanidinium salts, and quaternary ammonium salts. Examples of the anion constituting the salt include methyl- and ethyl carbonate anions.
Of (D121), from the viewpoint of low colorability, amidinium alkyl (C1-3) carbonate and guanidinium alkyl (C1-3) carbonate are more preferable, and imidazolinium methyl carbonate and imidazo are more preferable. It is a guanidinium methyl carbonate having a rhinium skeleton.

(D122) include sulfonic acid (polyethylene sulfonic acid, lauryl sulfonic acid, etc.) salt, sulfate ester (lauryl alcohol sulfate ester, lauryl alcohol EO 3 mol adduct sulfate ester, etc.) salt, phosphate ester (octyl alcohol phosphate ester, Lauryl alcohol EO 3 mol adduct phosphate ester, etc.) and the like. Examples of the cation constituting the salt include alkali metal (lithium, sodium, potassium, etc.) ions.
Of the (D122), sulfonate is preferable from the viewpoint of antistatic properties.

  (D123) includes EO adducts of higher alcohols (C8-24, such as oleyl alcohol, lauryl alcohol and stearyl alcohol), PEG fatty acid esters, polyhydric alcohols (C2-20, such as GR, PE, SO and sorbitan). Fatty acid esters and the like can be mentioned, and from the viewpoint of antistatic properties, polyhydric alcohol fatty acid esters are preferable.

  The amount of (D12) used is usually 30% or less based on the total weight of the composition of the present invention, and preferably 10 to 25% from the viewpoint of antistatic properties and light transmittance of the cured product.

  When the additives are the same and overlap between (D1) to (D12) above, the amount of each additive exerting the corresponding additive effect is not used regardless of the effect as the other additive, Considering that the effects as other additives can be obtained at the same time, the amount used is adjusted according to the purpose of use.

In order to adjust the viscosity of the present invention to a viscosity suitable for coating, the composition diluted with a solvent can be used as necessary.
The amount of the solvent used is usually 2,000% or less based on the total weight of the composition, and preferably 10 to 500% from the viewpoint of handling properties (workability) and the surface hardness of the cured product. The viscosity of the diluted composition is usually 5 to 500,000 mPa · s at the temperature during use (usually 5 to 60 ° C.), and preferably 10 to 10,000 mPa · s from the viewpoint of stable coating.

The solvent is not particularly limited as long as it dissolves the resin component in the composition of the present invention. Specifically, aromatic hydrocarbons (C7-10, eg toluene, xylene and ethylbenzene), esters or ether esters (C4-10, eg ethyl acetate, butyl acetate and methoxybutyl acetate), ethers [C4-10, eg Diethyl ether, tetrahydrofuran, monoethyl- and monobutyl ether of ethylene glycol (hereinafter abbreviated as EG), monomethyl ether of propylene glycol (hereinafter abbreviated as PG) and monoethyl ether of diethylene glycol (hereinafter abbreviated as DEG)], ketone (C3-10) , For example acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone and cyclohexanone), alcohols (C1-10, such as methanol, ethanol, n- and i-propano) , N-, i-, sec- and t-butanol, 2-ethylhexyl alcohol and benzyl alcohol), amides (C3-6, such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.), sulfoxides (C2-4, Examples thereof include dimethyl sulfoxide), water, and a mixed solvent of two or more thereof.
Of these solvents, ketones and alcohols are preferable from the viewpoint of the drying process time, and ethyl acetate, methyl ethyl ketone, i-propanol and mixtures thereof are more preferable.

The composition of the present invention is diluted with a solvent if necessary, applied to at least a part of at least one side of the substrate, and dried if necessary, and then irradiated with active energy rays (ultraviolet rays, electron beams, X-rays, etc.). Thus, an optical sheet having a cured product on at least a part of the front surface and / or back surface of the substrate can be obtained.
In the coating, a commonly used apparatus such as a coating machine [bar coater, gravure coater, roll coater (size press roll coater, gate roll coater, etc.), air knife coater, spin coater, blade coater, etc.] can be used. The coating film thickness is usually 0.5 to 300 μm as the film thickness after curing and drying, and the preferable upper limit is 250 μm from the viewpoint of drying property and curability, and the preferable lower limit is from the viewpoint of wear resistance, solvent resistance, and contamination resistance. Is 1 μm.

  When the composition of the present invention is used after being diluted with a solvent, it is preferably dried after coating. Examples of the drying method include hot air drying (such as a dryer). The drying temperature is usually 10 to 200 ° C., the upper limit is preferably 150 ° C. from the viewpoint of the smoothness and appearance of the coating film, and the lower limit is preferably 30 ° C. from the viewpoint of the drying speed.

When the composition of the present invention is cured by ultraviolet irradiation, a known ultraviolet irradiation device [for example, trade name “Eye Grandage”, manufactured by Eyegraphic Co., Ltd.] can be used. The dose of the ultraviolet radiation is typically 10~10,000mJ / cm ^2, a preferred upper limit of a flexible viewpoint of curing was 5,000 mJ / cm ^2, preferably lower from the viewpoint of curability of the composition is 100 mJ / cm ² It is.

  When the composition of the present invention is cured by electron beam irradiation, a known electron beam irradiation apparatus [for example, trade name “Electron Beam”, manufactured by Iwasaki Electric Co., Ltd.] can be used. The irradiation amount of electron beam is usually 0.5 to 20 Mrad, and the preferable lower limit from the viewpoint of the curability of the composition is 1 Mrad, the flexibility of the cured product, and avoiding damage to the cured product (coating film) or the substrate From the viewpoint, a preferable upper limit is 15 Mrad.

  The composition of the present invention is usually cured by active energy rays (ultraviolet rays, electron beams, X-rays, etc.), but can be cured by heat when it contains a thermal polymerization initiator (B2). In the case of curing with heat, the heat treatment is usually performed in an oven at 50 to 200 ° C., preferably from 80 to 180 ° C. from the viewpoint of curability and low colorability, for 1 minute to 20 hours.

The optical sheet of the present invention includes a prism sheet for improving the brightness of a liquid crystal display device, a light diffusion sheet, a Fresnel lens for projection television, and a lenticular lens.
Although it does not specifically limit as a base material used in order to create these optical sheets, Various sheets, a film, and a board | plate material are mentioned.
PET sheet, polycarbonate sheet, polystyrene sheet as sheet; PET film, triacetyl cellulose film, etc. as film; polymethyl acrylate (hereinafter abbreviated as PMMA) plate, methyl methacrylate / styrene copolymer as plate material (Hereinafter abbreviated as MS) Plates, glass plates and the like can be mentioned.

  When producing an optical sheet, the above-mentioned various sheets, films, and plate materials are applied to the prism sheet and the light diffusing sheet, dried and cured, and the mold is used for the Fresnel lens and the lenticular lens for projection television. A resin is applied to the substrate, and the above various sheets, films, and plate materials are bonded together, and then cured by the above method.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by this. In the following, “part” represents “part by weight”, and “%” represents “% by weight”.

Production Example 1
Styrene-maleic anhydride copolymer resin [trade name “SMA2000”, manufactured by Sartomer Co., Ltd., styrene / maleic anhydride copolymer ratio (molar ratio) 2/1 in a reaction vessel equipped with a condenser, a stirrer, and a thermometer. . Tg of styrene homopolymer is 109 ° C. ] 43.1 parts and 156.8 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) were added and heated and stirred at 90 ° C. to dissolve uniformly. To this solution, 2-hydroxyethyl acrylate [trade name “Light Ester HOA”, manufactured by Kyoeisha Chemical Co., Ltd., and the same shall apply hereinafter. 14.9 parts and hydroquinone 0.1 part were added, and the mixture was heated and stirred for 30 hours to reflux. The solution was allowed to cool to obtain a copolymer (A-1) solution having a solid content of 27%. The acid value of the solution was 37 mgKOH / g.

Production Example 2
After putting 48.7 parts of methyl ethyl ketone into a reaction vessel similar to Production Example 1 and heating to 80 ° C., 7.4 parts of glycidyl methacrylate [trade name “Light Ester G”, manufactured by Kyoeisha Chemical Co., Ltd.], isobornyl Acrylate [trade name “Light Acrylate IB-XA”, manufactured by Kyoeisha Chemical Co., Ltd. The Tg of the homopolymer is 95 ° C. ] 12.1 parts, and 2,2′-azobis (2,4-dimethylvaleronitrile) [trade name “V-65”, manufactured by Wako Pure Chemical Industries, Ltd. same as below. Each solution of 1.5 parts dissolved in 24.3 parts of MEK was added dropwise simultaneously over 6 hours, and then heated and stirred for 3 hours to reflux. After allowing to cool to 65 ° C., 6.0 parts of 2-hydroxyethyl acrylate was added, and the mixture was heated to 80 ° C. for 10 hours with stirring and refluxed. The solution was allowed to cool to obtain a copolymer (A-2) solution having a solid content of 27%.

Production Example 3
After putting 48.7 parts of methyl ethyl ketone in a reaction vessel similar to Production Example 1 and heating to 80 ° C., 3.1 parts of glycidyl methacrylate [trade name “Light Ester G”, manufactured by Kyoeisha Chemical Co., Ltd.], isobornyl Methacrylate [trade name “Light Ester IB-X”, manufactured by Kyoeisha Chemical Co. The Tg of the homopolymer is 180 ° C.] 19.3 parts, and 1.5 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) dissolved in 24.3 parts of MEK over 6 hours. Were added dropwise at the same time, followed by heating and stirring for 3 hours to reflux. After cooling to 65 ° C., 3.1 parts of 2-hydroxyethyl acrylate was added, and the mixture was heated to 80 ° C. for 10 hours with stirring and refluxed. The solution was allowed to cool to obtain a copolymer (A-3) solution having a solid content of 27%.

Production Example 4
After putting 48.7 parts of methyl ethyl ketone into a reaction vessel similar to Production Example 1 and heating to 80 ° C., 4.0 parts of glycidyl methacrylate [trade name “Light Ester G”, manufactured by Kyoeisha Chemical Co., Ltd.], trifluoromethyl Methacrylate [trade name “Light Ester M-3F”, manufactured by Kyoeisha Chemical Co., Ltd. Homopolymer Tg is 90 ° C.] 17.5 parts and 2,2′-azobis (2,4-dimethylvaleronitrile) 1.5 parts dissolved in MEK 24.3 parts over 6 hours respectively Were added dropwise at the same time, followed by heating and stirring for 3 hours to reflux. After allowing to cool to 65 ° C, 4.0 parts of 2-hydroxyethyl acrylate was added, and the mixture was heated to 80 ° C for 10 hours with stirring and refluxed. The solution was allowed to cool to obtain a copolymer (A-4) solution having a solid content of 27%.

Production Example 5
In the same reaction vessel as in Production Example 1, bisphenol A EO 10 mol adduct [trade name “New Pole BPE100”, Sanyo Chemical Industries, Ltd.] 77.8 parts, maleic anhydride 5.7 parts and dibutyltin oxide 0 0.03 part was charged and dehydrated under the conditions of 10 mmHg and 200 ° C. for esterification. After 13.4 parts of xylylene diisocyanate [trade name “Takenate 500”, manufactured by Mitsui Takeda Chemical Co., Ltd.] was added to the obtained polyester and reacted at 85 ° C. for 2 hours, 3.1 parts of 2-hydroxyethyl acrylate was then added. In addition, it was made to react at 85 degreeC for 3 hours, and 100 parts of copolymers (A-5) were obtained. (A-5) was diluted with MEK to obtain a urethane acrylate (A-5) solution having a solid content of 27%.

Examples 1-6, Comparative Examples 1-4
It mix | blended in the ratio shown in Table 1, and obtained the active energy ray hardening-type resin composition (Examples 1-6, Comparative Examples 1-4) for optical sheets.

（Ａ−６）の溶液：ポリテトラメチレングリコール（以下ＰＴＭＧと略記）ウレタンアク
リレート［商品名「ＮＫオリゴＵＡ−１６０Ｔ」、新中村化学工業（株）製
］のＭＥＫ溶液（固形分２７％）
（Ｂ−１）：光重合開始剤［１−ヒドロキシシクロヘキシルフェニルケトン、
商品名「イルガキュアー１８４」、チバ・スペシャリティ・ケミ
カルズ（株）製］
（Ｃ−１）：多官能アクリレート［ジペンタエリスリトールヘキサアクリレー
ト、商品名「ネオマー ＤＡ−６００」、三洋化成工業（株）製］
（Ｃ−２）：多官能アクリレート［ペンタエリスリトールトリアクリレート、
商品名「ライトアクリレートＰＥ−３Ａ」、共栄社化学（株）製］

Solution (A-6): Polytetramethylene glycol (hereinafter abbreviated as PTMG)
Relate [trade name "NK Oligo UA-160T", manufactured by Shin-Nakamura Chemical Co., Ltd.
] MEK solution (solid content 27%)
(B-1): Photopolymerization initiator [1-hydroxycyclohexyl phenyl ketone,
Product name "Irgacure 184", Ciba Specialty Chemi
Culls Co., Ltd.]
(C-1): Multifunctional acrylate [dipentaerythritol hexaacrylate
G, “Neomer DA-600”, manufactured by Sanyo Chemical Industries Ltd.]
(C-2): Multifunctional acrylate [pentaerythritol triacrylate,
Product name “Light Acrylate PE-3A”, manufactured by Kyoeisha Chemical Co., Ltd.]

A cured product (film) was prepared in the following manner using each of the above compositions, and evaluated according to the following method. The results are shown in Table 1.
(Preparation of sample) [For evaluating water absorption and linear expansion coefficient]
The composition is placed in a space partitioned by a silicon spacer on a glass plate and spread with a bar coater so that the thickness after curing is 500 μm. Name “Igrandage”, manufactured by iGraphic. same as below. ] Was irradiated with ultraviolet rays at 1,000 mJ / cm ² and cured, and then the glass plate was removed to obtain a cured product (film).

(Evaluation methods)
(1) Linear expansion coefficient (dimensional stability)
The linear expansion coefficient in a temperature range of 30 to 80 ° C. was measured according to ASTM D696.
(2) Light transmittance A PET film with a thickness of 100 μm [trade name “Toyobo Ester Film”, manufactured by Toyobo Co., Ltd.] was coated so that the film thickness after curing was 30 μm, dried, and then irradiated with ultraviolet rays. Light transmittance (%) was measured in accordance with ASTM D1003 for a cured product (film) that was cured by irradiating with ultraviolet rays at 1,000 mJ / cm ² with an apparatus.
(3) Water absorption rate The water absorption rate was measured according to ASTM D570. The water absorption rate (%) was obtained from the following formula.

Water absorption rate = (weight after water immersion−weight before water immersion) × 100 / (weight before water immersion)

  From the results of Table 1, a cured product (film) obtained by curing the composition of the present invention (Examples 1 to 6) is a cured product (film) obtained by curing a comparative composition (Comparative Examples 1 to 4). It can be seen that the dimensional stability and light transmittance are superior to those of FIG.

  The cured product obtained by curing the active energy ray-curable resin composition for an optical sheet of the present invention is excellent in dimensional stability and light transmission, and therefore is used for applications requiring dimensional stability and light transmission [optical sheet. (Such as prism sheets for improving the brightness of liquid crystal display devices, light diffusion sheets, Fresnel lenses for projection televisions, lenticular lenses) and the like].

Claims (6)

Copolymer (A) having at least one (meth) acryloyl group, and a polymerization initiator (B) having an ethylenically unsaturated monomer (a1) having a glass transition temperature of 80 to 250 ° C. as a structural unit And an active energy ray-curable resin composition for an optical sheet, comprising a polyfunctional (meth) acrylate (C) having 3 to 6 (meth) acryloyl groups. Furthermore, it comprises at least one monomer selected from the group consisting of ethylenically unsaturated monomers (a3) other than (a1), which has a functional group reactive with hydroxyl-containing (meth) acrylates (a2) and (a2) 2. A composition according to claim 1 in addition to units. The composition according to claim 1 or 2, wherein the proportion of (a1) in (A) is 30 to 90% by weight. Hardened | cured material formed by hardening the composition in any one of Claims 1-3. An optical sheet having the cured product according to claim 4 on at least a part of at least one side of a substrate. A method for producing an optical sheet, wherein the composition according to any one of claims 1 to 3 is applied to at least a part of at least one side of a substrate, and is cured by irradiation with active energy rays.