JP2017082204A - Active energy ray-curable resin composition and coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-curable resin composition that gives extremely high hardness and excoriation resistance when forming a cured coating film and moreover, can form a cured coating film resistant to curling.SOLUTION: An active energy ray-curable resin composition has a urethane (meth) acrylate composition (A) obtained by the reaction between a (meth) acrylic acid adduct of dipentaerythritol with a hydroxyl value of 60 mgKOH/g or more (a) and polyvalent isocyanate (b), and silica (B).SELECTED DRAWING: None

Description

  The present invention relates to an active energy ray-curable resin composition comprising a urethane (meth) acrylate composition and a coating agent. More specifically, the present invention has extremely high hardness and scratch resistance when a cured coating film is formed. The present invention relates to an active energy ray-curable resin composition capable of forming a cured coating film which is obtained and hardly curled, and a coating agent using the same.

  Conventionally, an active energy ray-curable resin composition is cured by irradiation with an active energy ray such as a very short time of radiation or ultraviolet rays, so that it can be used as a coating agent or adhesive on various substrates, or an anchor coating agent, etc. Widely used, urethane (meth) acrylate compounds and polyfunctional monomers are used as the curing component. However, when the active energy ray-curable resin composition is used as a coating agent, particularly as a coating agent for a hard coat, there is a problem that the cured film shrinks and the cured film tends to curl. There is a need for hard-to-harden coatings.

  In recent years, in order to reduce the thickness and weight of electronic devices, development of a material in which a hard coat is applied to a resin plate instead of a heavy glass substrate has been advanced. The coating agent for hard coat used in them is required to be able to form a coating layer with higher hardness than before, and there is a coating agent that can obtain a coating layer with ultra-high hardness and less curing shrinkage. It has been demanded.

  As a technique for obtaining a coating layer having ultra-high hardness and low curing shrinkage, for example, Patent Document 1 discloses a colloidal surface-treated with a hexafunctional urethane acrylate, a tetrafunctional or higher acrylic monomer, and a specific silane coupling agent. A hard coat composition combining silica is disclosed. According to this hard coat composition, it has a further improved surface hardness, does not generate cracks at the time of curing, and does not cause problems such as warping or curl of the plastic film, hardness and low curing shrinkage. It is described that a hard coat agent can be obtained (see paragraphs [0005] to [0007]).

JP 2008-150484 A

  However, in the technique disclosed in Patent Document 1, since the active energy ray curable resin to be used is a general polyfunctional urethane (meth) acrylate or polyfunctional (meth) acrylate monomer, curing shrinkage becomes large. The curl resistance is considered to be insufficient. Further, as described in the examples, in order to apply a thick film of 20 μm or more, the final nonvolatile content of the hard coat composition needs to be at least 40% by weight or more. This requires a cumbersome work of blending after the solvent of the colloidal silica is distilled off under reduced pressure, and is inferior in thick film coatability.

  In view of the above situation, in the present invention, when forming a cured coating film, an active energy ray curability that can form a cured coating film that has extremely high hardness and scratch resistance and is difficult to curl. It is an object of the present invention to provide a resin composition and a coating agent using the same.

  However, as a result of intensive studies in view of such circumstances, the present inventors have obtained a urethane (meth) acrylate composition and silica obtained by reacting a (meth) acrylic acid adduct of dipentaerythritol with a polyvalent isocyanate. Furthermore, by using an adduct having a higher hydroxyl value than usual in the (meth) acrylic acid adduct of dipentaerythritol, it has extremely high hardness and scratch resistance, and has a small curing shrinkage and is difficult to curl. It discovered that a cured coating film was obtained and completed this invention.

That is, the active energy ray-curable resin composition of the present invention is obtained by reacting a (meth) acrylic acid adduct (a) of dipentaerythritol having a hydroxyl value of 60 mgKOH / g or more with a polyvalent isocyanate (b). The urethane (meth) acrylate composition (A) and silica (B) obtained in this manner are contained.
Moreover, the coating agent of this invention contains the active energy ray-curable resin composition of this invention, It is characterized by the above-mentioned.

  According to the active energy ray-curable resin composition of the present invention, a cured coating film having a very high hardness and hardly cured and contracted can be obtained. Therefore, the composition of the present invention is a coating agent, particularly a coating agent for hard coat and optical coating. It is useful as a film coating agent. It is also useful as a paint or ink. Furthermore, since the active energy ray-curable resin composition of the present invention can be easily adjusted to have a high viscosity, it has excellent thick film coatability.

Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate.

  The active energy ray-curable resin composition of the present invention is obtained by reacting a (meth) acrylic acid adduct (a) of dipentaerythritol having a hydroxyl value of 60 mgKOH / g or more with a polyvalent isocyanate (b). The urethane (meth) acrylate-based composition (A) and silica (B) are contained.

  Such a urethane (meth) acrylate composition (A) includes a hydroxyl group in a (meth) acrylic acid adduct (a) of dipentaerythritol having a hydroxyl value of 60 mgKOH / g or more, and an isocyanate of a polyvalent isocyanate (b). By reacting with a group, a urethane bond is formed and obtained.

The hydroxyl value of the (meth) acrylic acid adduct (a) of dipentaerythritol needs to be 60 mgKOH / g or more, preferably 63 to 120 mgKOH / g, particularly preferably 65 to 100 mgKOH / g. is there.
If the hydroxyl value is too small, the content of dipentaerythritol hexa (meth) acrylate, which has a low molecular weight and a large number of ethylenically unsaturated groups and does not react with isocyanate, increases, resulting in an increase in curing shrinkage during curing and curling. It tends to be easy and the flexibility tends to decrease. In addition, when the said hydroxyl value becomes large too much, there exists a tendency for a viscosity to become high with the increase in molecular weight, and to become difficult to handle.

As the (meth) acrylic acid adduct (a) of dipentaerythritol, a product obtained by reacting dipentaerythritol and (meth) acrylic acid by a known general method is used, and usually a mixture of a plurality of reaction products. Exist.
As the (meth) acrylic acid adduct (a) of dipentaerythritol, one of (meth) acrylic acid added to dipentaerythritol, two added, and three added to the component. And those with four additions, those with five additions, and those with six additions, and satisfy the above hydroxyl values as a whole.
In adjusting the hydroxyl value, for example, the mixing ratio of adducts from one to six is added.

  Examples of the polyvalent isocyanate (b) include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Isocyanates; aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate; hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis ( Isocyanatomethyl) cyclohex Alicyclic polyisocyanates such as styrene; or trimer compounds or multimeric compounds of these polyisocyanates, allophanate type polyisocyanates, burette type polyisocyanates, water-dispersed polyisocyanates (for example, "Aqua" manufactured by Tosoh Corporation) Nate 100 "," Aquanate 105 "," Aquanate 120 "," Aquanate 210 ", etc.). These can be used alone or in combination of two or more.

  The polyvalent isocyanate (b) may be various polyols such as low molecular weight polyols and high molecular weight polyols, among which polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, (meta ) A reaction product with a polyol such as an acrylic polyol may be used.

  Among these, aliphatic polyisocyanates and alicyclic polyisocyanates are preferable in terms of weather resistance and strength, and particularly preferable are trimers of hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and isophorone diisocyanate. is there.

  The urethane (meth) acrylate composition (A) used in the present invention is a functional group comprising the isocyanate group of the polyvalent isocyanate (b) and the hydroxyl group of the (meth) acrylic acid adduct (a) of dipentaerythritol. It can be obtained by adjusting the molar ratio of the group and, if necessary, using a catalyst such as dibutyltin dilaurate to react the polyisocyanate (b) with the (meth) acrylic acid adduct of dipentaerythritol (a). it can.

  The reaction molar ratio of the charge of the polyvalent isocyanate (b) and the (meth) acrylic acid adduct (a) of dipentaerythritol is a polyvalent isocyanate (b) having two isocyanate groups. Isocyanate (b): Dipentaerythritol (meth) acrylic acid adduct (a) is about 1: 2 to 1: 5.

  When the proportion of the (meth) acrylic acid adduct (a) of dipentaerythritol is too large, the amount of low molecular weight monomers increases, and the shrinkage of curing increases, which tends to increase curl. When the ratio of the acrylic acid adduct (a) is too small, unreacted isocyanate remains, and the stability and safety of the cured coating film tend to be lowered.

  The reaction between the (meth) acrylic acid adduct (a) of dipentaerythritol and the polyvalent isocyanate (b) is usually performed by the above (meth) acrylic acid adduct (a) of the dipentaerythritol and the polyvalent isocyanate (b). Can be carried out in batch or separately in the reactor.

  In the above reaction, it is also preferable to use a catalyst for the purpose of accelerating the reaction. Examples of such a catalyst include dibutyltin dilaurate, dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, bisacetylacetonate. Organometallic compounds such as zinc, zirconium tris (acetylacetonate) ethylacetoacetate, zirconium tetraacetylacetonate; tin octenoate, zinc hexanoate, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate , Metal salts such as stannous chloride, stannic chloride and potassium acetate: triethylamine, triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4, 0] Undese Amine catalysts such as N, N, N ', N'-tetramethyl-1,3-butanediamine, N-methylmorpholine, N-ethylmorpholine; bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, etc. In addition, organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate, 2-ethylhexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanoic acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, Bismuth-based catalysts such as bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bis-neodecanoate, bismuth disalicylate, bismuth digallate, etc. Among them, dibutyltin dilaurate, 1, - diazabicyclo [5,4,0] undecene is preferred. These may be used alone or in combination of two or more.

  Organic solvents having no functional group that reacts with isocyanate groups, for example, esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; organics such as aromatics such as toluene and xylene A solvent can be used.

  The reaction temperature is usually 30 to 90 ° C., preferably 40 to 80 ° C., and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

A urethane (meth) acrylate composition (A) is thus obtained. As a weight average molecular weight of this urethane (meth) acrylate type composition (A), it is preferable that it is 3,000-100,000, Especially preferably, it is 3,200-50,000, More preferably, it is 3,500- 5,000.
If the weight average molecular weight is too small, the cured coating film tends to be brittle, and if it is too large, the viscosity tends to be too high and difficult to handle.

In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, a column: Shodex GPC KF-806L (in Showa Denko Co., Ltd. make, "Shodex GPC system-11 type | mold"). Exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plate / book, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) 3 Measured by using this series.

The viscosity of the urethane (meth) acrylate composition (A) at 60 ° C. is preferably 2,000 to 200,000 mPa · s, particularly preferably 5,000 to 100,000 mPa · s, and still more preferably. Is 10,000 to 80,000 mPa. When the viscosity is out of the above range, the coatability tends to be lowered.
In addition, the measuring method of a viscosity is based on an E-type viscometer.

  The urethane (meth) acrylate composition (A) of the present invention contains a plurality of types of urethane (meth) acrylates, and further includes a plurality of types of curing monomer components such as (meth) acrylic acid of dipentaerythritol. Dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) which are adducts (a) An acrylate, polypentaerythritol poly (meth) acrylates other than the above may also be contained.

  The urethane (meth) acrylate content in the urethane (meth) acrylate-based composition (A) of the present invention is preferably 50% by weight or more, particularly preferably 60% by weight or more, and still more preferably 70% by weight or more. Preferably it is 80 weight% or more.

Next, silica (B) will be described.
Silica (B) in the present invention is not particularly limited, but finely modified silica containing no dispersion medium, silica dispersion (silica sol) in which silica is dispersed in a dispersion medium, and surface modification with a coupling agent or the like. And the like.

  Such a dispersion medium is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol; cellosolves such as ethyl cellosolve; glycol ethers such as propylene glycol monomethyl ether; acetone, Ketones such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; polyhydric alcohols such as ethylene glycol and derivatives thereof; acrylates such as 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate Others include water, ethyl acetate, butyl acetate, toluene, xylene, diacetone alcohol, and the like. Among these, propanol, n-butanol, i-butanol, methyl isobutyl ketone, methyl ethyl ketone, and toluene are preferable in terms of the coating film appearance.

  Further, the content of silica in the silica dispersion obtained by dispersing silica in the dispersion medium is preferably 10 to 70% by weight and particularly preferably 15 to 50% by weight in the silica dispersion. If the content is too small, the amount of the solvent contained in the composition after blending becomes relatively large, so that the viscosity tends to be low, which tends to be a problem from the viewpoint of coating suitability. There is a tendency to be inferior in stability.

These silicas (B) may be used alone or in combination of two or more.
For example, when two or more types of silica sols in which silica is dispersed in a dispersion medium are used in combination, silica sol in which the dispersion medium is a glycol ether such as propylene glycol monomethyl ether, and the dispersion medium is a ketone such as methyl ethyl ketone or an alcohol such as methanol. The silica sol is a combination of silica sol, the dispersion medium is a ketone such as methyl ethyl ketone, and the silica sol is a dispersion medium being an alcohol such as methanol, and the dispersion medium is selected from two or more alcohols such as methanol. It is preferable from the viewpoint of the appearance of the coating film to use a silica sol which is a liquid.

The average particle diameter of the silica (B) used in the present invention is preferably 3 to 100 nm, particularly preferably 5 to 50 nm, and further preferably 5 to 20 nm. When the average particle diameter of silica (B) is too large, the transparency of the coating film tends to be inferior. In particular, when the average particle size is 50 nm or less, the transparency when the coating film is formed is high and suitable for optical applications.
In addition, this average particle diameter is an average particle diameter measured by BET method.

  Specific examples of the silica (B) include methanol silica sol (methanol dispersion, particle size 10 to 15 nm), MA-ST-M (methanol dispersion, average particle size 20 to 25 nm), MA-ST-L (methanol). Dispersion, average particle size 40-50 nm), IPA-ST (2-propanol dispersion, average particle size 10-15 nm), IPA-ST-UP (2-propanol dispersion, particle size 9-15 nm, chain) PGM-ST (1-methoxy-2-propanol dispersion, average particle diameter 10-15 nm), EG-ST (ethylene glycol dispersion, particle diameter 10-20 nm), EAC-ST (ethyl acetate dispersion, particle diameter 10-15 nm), MEK- ST (methyl ethyl ketone dispersion, average particle size 10-15 nm), MEK-ST-40 (methyl ethyl ketone dispersion, average particle size 1) ˜15 nm), MEK-ST-L (methyl ethyl ketone dispersion, average particle size 40-50 nm), MIBK-ST (methyl isobutyl ketone dispersion, average particle size 10-15 nm), MIBK-ST-L (methyl isobutyl ketone dispersion, average) Particle diameter 40-50 nm), MEK-EC-2130Y (methyl ethyl ketone dispersion, particle diameter 10-15 nm, surface modification grade), MEK-AC-2140Z (methyl ethyl ketone dispersion, particle diameter 10-15 nm, surface modification grade), MEK -AC-4130Y (methyl ethyl ketone dispersion, particle diameter 40-50 nm, surface modified grade), PGM-AC-2140Y (propylene glycol monomethyl ether dispersion, particle diameter 10-15 nm, surface modified grade), PGM-AC-4130Y ( Propylene glycol Monomethyl ether dispersion, particle diameter 40-50 nm, surface modification grade), MIBK-AC-2140Z (methyl isobutyl ketone dispersion, particle diameter 10-15 nm, surface modification grade) (all manufactured by Nissan Chemical Industries, Ltd.) It is done.

In this invention, it is preferable that content of the said silica (B) is 10 to 70 weight% with respect to the whole non volatile matter of the active energy ray curable resin composition of this invention, Most preferably, it is 15-60. % By weight, more preferably 20-50% by weight.
In addition, when using a silica dispersion as silica (B), content of a silica (B) means content of a non volatile matter.

In the active energy ray-curable resin composition of the present invention, the content ratio (weight ratio) of the urethane (meth) acrylate composition (A) and silica (B) is (A) :( B) = 30: 70- It is preferably 90:10, particularly preferably (A) :( B) = 40: 60 to 80:20, more preferably (A) :( B) = 45: 55 to 75:25.
If the content of the urethane (meth) acrylate-based composition (A) is too small, the content of the silica (B) tends to be relatively large and the cured coating film tends to become brittle, and the urethane (meth) acrylate-based When there is too much content of a composition (A), there exists a tendency for content of a silica (B) to decrease too much, and for hardening shrinkage to become large.

  The active energy ray-curable resin composition of the present invention contains at least the urethane (meth) acrylate-based composition (A) and silica (B), and the composition further starts photopolymerization. It is preferable to contain an agent. Moreover, in the range which does not impair the effect of this invention, you may contain ethylenically unsaturated monomers other than urethane (meth) acrylate, an acrylic resin, a surface conditioner, a leveling agent, a polymerization inhibitor, etc. further. Furthermore, fillers, dyes and pigments, oils, plasticizers, waxes, desiccants, dispersants, wetting agents, gelling agents, stabilizers, antifoaming agents, surfactants, leveling agents, thixotropic agents, antioxidants It is also possible to contain a flame retardant, an antistatic agent, a filler, a reinforcing agent, a matting agent, a crosslinking agent, a zirconium compound, a preservative, and the like.

  In this invention, content of components (except a volatile component) other than said urethane (meth) acrylate type composition (A) and silica (B) is the whole non-volatile component of an active energy ray-curable resin composition. On the other hand, it is preferably 20% by weight or less, particularly preferably 15% by weight or less.

  Examples of the ethylenically unsaturated monomer other than urethane (meth) acrylate include a monofunctional monomer, a bifunctional monomer, and a trifunctional or higher polyfunctional monomer.

  Examples of such monofunctional monomers include styrene monomers such as styrene, vinyl toluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, acrylonitrile, 2-methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2-hydroxy -3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate Rate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate (2-methyl-2-ethyl-1,3-dioxolan-4-yl) -methyl (meth) acrylate, cyclohexanespiro-2- (1,3-dioxolan-4-yl) -methyl (meth) acrylate, 3-ethyl-3-oxetanylmethyl (meth) acrylate, γ-butyrolactone (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) Acu Rate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified (n = 2) (meth) acrylate, nonylphenol propylene Half (meth) acrylates of phthalic acid derivatives such as oxide-modified (n = 2.5) (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, Furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) (Meth) acrylate monomers such as acrylate, (meth) acryloylmorpholine, polyoxyethylene secondary alkyl ether acrylate, 2-hydroxyethylacrylamide, N-methylol (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine And vinyl acetate.

  Examples of such bifunctional monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and di Propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A Type di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, ethoxylated cyclohexanedimethanol di (me ) Acrylate, dimethylol dicyclopentane di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) Acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid modified neopentyl glycol di (meth) acrylate, ethylene isocyanurate Examples thereof include oxide-modified diacrylate and bis (2- (meth) acryloyloxyethyl) acid phosphate.

  Examples of the tri- or higher functional monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified triacrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol hexa (Meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, capro Kuton modified pentaerythritol tetra (meth) acrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol Examples include tetra (meth) acrylate and ethoxylated 15 glycerin triacrylate.

  Further, a Michael adduct of acrylic acid or 2-acryloyloxyethyl dicarboxylic acid monoester can be used in combination. Examples of such a Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, and methacrylic acid. A trimer, an acrylic acid tetramer, a methacrylic acid tetramer, etc. are mentioned. The 2-acryloyloxyethyl dicarboxylic acid monoester is a carboxylic acid having a specific substituent, such as 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, other oligoester acrylates can be mentioned.

  These ethylenically unsaturated monomers may be used alone or in combination of two or more.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy- 2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propane, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy-2-methyl Acetophenones such as -1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, o-benzoylbenzoate Acid methyl, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, Benzophenones such as 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride; -Isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl Thioxanthones such as -9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine And acyl phosphine oxides such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, only 1 type may be used independently among these photoinitiators, and 2 or more types may be used together.

  These auxiliary agents include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid. Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. can be used in combination.

  Among these photopolymerization initiators, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoyl isopropyl ether, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-hydroxy-2- It is preferable to use methyl-1-phenylpropan-1-one.

As content of a photoinitiator, it is preferable that it is 0.1-20 weight part with respect to 100 weight part of hardening components contained in a composition, Most preferably, it is 0.5-10 weight part, Furthermore, Preferably it is 1-10 weight part.
If the content of the photopolymerization initiator is too small, curing tends to be poor and film formation tends to be difficult, and if too large, yellowing of the cured coating tends to occur, and coloring problems tend to occur.

  It does not specifically limit as a surface conditioning agent, For example, a cellulose resin, an alkyd resin, etc. can be mentioned. Such a cellulose resin has an action of improving the surface smoothness of the coating film, and an alkyd resin has an action of imparting a film-forming property at the time of coating.

  As the leveling agent, a known general leveling agent can be used as long as it has a wettability imparting action to the base material of the coating liquid and a surface tension reducing action. For example, a silicone-modified resin, a fluorine-modified resin, An alkyl-modified resin or the like can be used.

  Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, hydroquinone monomethyl ether, mono-t- Examples thereof include butyl hydroquinone and pt-butyl catechol.

  Moreover, it is also preferable to use the organic solvent for dilution for the active energy ray curable resin composition of this invention as needed, in order to make the viscosity at the time of coating appropriate. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol; ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone; cellosolves such as ethyl cellosolve; toluene and xylene And the like; glycol ethers such as propylene glycol monomethyl ether; acetates such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol. These organic solvents may be used alone or in combination of two or more.

  When two or more organic solvents are used in combination, a combination of glycol ethers such as propylene glycol monomethyl ether and ketones such as methyl ethyl ketone or alcohols such as methanol, or ketones such as methyl ethyl ketone and alcohols such as methanol From the viewpoint of the appearance of the coating film, it is preferable to use two or more types in combination or from alcohols such as methanol.

  The active energy ray-curable resin composition of the present invention can be effectively used as a curable composition for forming a coating film such as a topcoat agent and an anchor coat agent on various substrates. (After further drying if a composition diluted with an organic solvent is applied), it is cured by irradiation with active energy rays.

  Examples of the base material to which the active energy ray-curable resin composition of the present invention is applied include, for example, polyolefin resin, polyester resin, polycarbonate resin, acrylonitrile butadiene styrene copolymer (ABS), and polystyrene resin. And plastic substrates such as molded products (films, sheets, cups, etc.), optical films such as polyethylene terephthalate films, triacetyl cellulose films, cycloolefin films, composite substrates thereof, glass fibers and inorganic substances Examples include mixed base materials of the above materials, metals (aluminum, copper, iron, SUS, zinc, magnesium, alloys thereof, etc.) and glass, and base materials provided with a primer layer on these base materials. It is done.

  Examples of the coating method of the active energy ray-curable resin composition of the present invention include wet coating methods such as spray, shower, gravure, dipping, roll, spin, screen printing, etc. Under, it can be applied to the substrate.

  Moreover, the active energy ray-curable resin composition of the present invention may be applied as it is, or may be diluted with the organic solvent exemplified above and applied. In the case of dilution, the organic solvent is preferably used, and the non-volatile content is usually preferably 3 to 80% by weight, particularly preferably 5 to 60% by weight.

  As drying conditions after coating when the dilution with the organic solvent is performed, the temperature is usually 40 to 120 ° C. (preferably 50 to 100 ° C.), and the drying time is usually 1 to 20 minutes (preferably 2). -10 minutes).

The viscosity at 20 ° C. of the active energy ray-curable resin composition of the present invention is preferably 5 to 50,000 mPa · s, particularly preferably 10 to 10,000 mPa · s, and further preferably 50 to 5, 000 mPa. When the viscosity is out of the above range, the coatability tends to be lowered.
The viscosity is measured with a B-type viscometer.

  Examples of the active energy ray used when the active energy ray-curable resin composition coated on the substrate is cured include, for example, deep ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, X-rays, γ rays, etc. In addition to electromagnetic waves, electron beams, proton beams, neutron beams, and the like can be used, but curing by ultraviolet irradiation is advantageous from the viewpoint of curing speed, availability of an irradiation device, price, and the like. In addition, when performing electron beam irradiation, it can harden | cure even if it does not use a photoinitiator.

When curing by ultraviolet irradiation, use a high-pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, electrodeless discharge lamp, LED lamp, etc. that emits light in the wavelength range of 150 to 450 nm. Usually, ultraviolet rays of 30 to 3000 mJ / cm ² (preferably 100 to 1500 mJ / cm ² ) can be irradiated.
After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.

  The coating film thickness (film thickness after curing) is preferably 0.5 to 1000 μm in view of light transmission for allowing the photopolymerization initiator to react uniformly as an active energy ray-curable coating film. In particular, the thickness is preferably 1 to 500 μm, and more preferably 2 to 200 μm.

  The active energy ray-curable resin composition of the present invention is preferably used as a coating agent, and particularly preferably used as a hard coat coating agent or an optical film coating agent.

  The active energy ray-curable resin composition of the present invention forms a cured coating film that has extremely high hardness and scratch resistance when formed, and that is difficult to curl and has excellent substrate adhesion. In particular, it is useful as a coating agent, and also useful as a paint, ink, and the like.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “parts” and “%” mean weight basis.

  The following were manufactured as a urethane (meth) acrylate type composition (A).

[Production Example of Urethane (meth) acrylate Composition (A-1)]
Into a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas blowing port, an acrylic acid adduct 885. 4 g (1.06 mol), 2,6-di-tert-butylcresol 0.6 g as a polymerization inhibitor and 0.05 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 60 ° C., and the residual isocyanate group was 0.3 The reaction was terminated at the time of reaching%, and a urethane (meth) acrylate composition (A-1) was obtained.
The obtained urethane (meth) acrylate composition (A-1) had a weight average molecular weight of 4,300 and a viscosity at 60 ° C. of 15,000 mPa · s.

[Production Example of Urethane (meth) acrylate Composition (A-2)]
Into a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, an acrylic acid adduct of dipentaerythritol having an isophorone diisocyanate of 159.5 g (0.72 mol) and a hydroxyl value of 98 mgKOH / g 840. 5 g (1.48 mol), 2,6-di-tert-butylcresol 0.6 g as a polymerization inhibitor and 0.05 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 60 ° C., and the residual isocyanate group was 0.3 The reaction was terminated at the time of reaching%, and a urethane (meth) acrylate-based composition (A-2) was obtained.
The urethane (meth) acrylate composition (A-2) obtained had a weight average molecular weight of 4,700 and a viscosity at 60 ° C. of 65,000 mPa · s.

[Production Example of Urethane (Meth) acrylate Composition (A′-1)]
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 94 g of acrylic acid adduct of 66 g (0.3 mol) of isophorone diisocyanate and dipentaerythritol having a hydroxyl value of 48 mg KOH / g was added. 8 moles), 0.6 g of 2,6-di-tert-butylcresol as a polymerization inhibitor and 0.05 g of dibutyltin dilaurate as a reaction catalyst were reacted at 60 ° C., and the residual isocyanate group became 0.3%. Reaction was complete | finished at the time and the urethane (meth) acrylate type composition (A'-1) was obtained.
The obtained urethane (meth) acrylate composition (A′-1) had a weight average molecular weight of 2,200 and a viscosity at 60 ° C. of 1,500 mPa · s.

The following were used as silica (B).
(B-1) Silica sol using methyl ethyl ketone as a dispersion medium [trade name: MEK-ST-40, manufactured by Nissan Chemical Industries, Ltd. (colloidal silica with non-volatile content of 40%, average particle size of about 10 nm)]
(B-2) Silica sol using methyl ethyl ketone as a dispersion medium [trade name: MEK-AC2140Z, manufactured by Nissan Chemical Industries, Ltd. (non-volatile content: 45%, surface-reactive colloidal silica having an average particle size of about 10 nm)]

<Example 1> [Active energy ray-curable resin composition]
50 parts of the urethane (meth) acrylate composition (A-1) obtained above, 125 parts of silica (B-1) (nonvolatile content 50 parts), and α-hydroxyalkylphenone light as a photopolymerization initiator 4 parts of a polymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (nonvolatile content: 58%, viscosity: 60 mPa · s).

<Example 2> [Active energy ray-curable resin composition]
50 parts of the urethane (meth) acrylate composition (A-2) obtained above, 125 parts of silica (B-1) (nonvolatile content 50 parts), and α-hydroxyalkylphenone light as a photopolymerization initiator 4 parts of a polymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (non-volatile content: 58%, viscosity: 70 mPa · s).

<Example 3> [Active energy ray-curable resin composition]
55 parts of the urethane (meth) acrylate composition (A-2) obtained above, 112.5 parts of silica (B-1) (nonvolatile content 45 parts), and α-hydroxyalkylphenone as a photopolymerization initiator 4 parts of a photopolymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (non-volatile content 61%, viscosity 260 mPa · s).

<Example 4> [Active energy ray-curable resin composition]
60 parts of the urethane (meth) acrylate composition (A-2) obtained above, 100 parts of silica (B-1) (nonvolatile content 40 parts), and α-hydroxyalkylphenone light as a photopolymerization initiator 4 parts of a polymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (nonvolatile content 63%, viscosity 6,200 mPa · s).

<Example 5> [Active energy ray-curable resin composition]
70 parts of the urethane (meth) acrylate composition (A-2) obtained above, 75 parts of silica (B-1) (non-volatile content 30 parts), and α-hydroxyalkylphenone light as a photopolymerization initiator 4 parts of a polymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (nonvolatile content: 70%, viscosity: 16,000 mPa · s).

<Example 6> [Active energy ray-curable resin composition]
70 parts of the urethane (meth) acrylate composition (A-2) obtained above, 67 parts of silica (B-2) (non-volatile content 30 parts), and α-hydroxyalkylphenone light as a photopolymerization initiator 4 parts of a polymerization initiator (manufactured by BASF, “Irgacure 184”) was blended to obtain an active energy ray-curable resin composition (non-volatile content 74%, viscosity 140 mPa · s).

<Comparative example 1> [Active energy ray-curable resin composition]
70 parts of the urethane (meth) acrylate composition (A′-1) obtained above, 75 parts of silica (B-1) (nonvolatile content 30 parts), and α-hydroxyalkylphenone system as a photopolymerization initiator 4 parts of a photopolymerization initiator (“Irgacure 184” manufactured by BASF Corporation) was blended to obtain an active energy ray-curable resin composition (nonvolatile content: 70%, viscosity: 40 mPa · s).

<Comparative Example 2> [Active energy ray-curable resin composition]
70 parts of dipentaerythritol hexaacrylate (DPHA), 75 parts of silica (B-1) (30 parts of non-volatile content), and α-hydroxyalkylphenone photopolymerization initiator (manufactured by BASF, “Irgacure”) 184 ") was blended to obtain an active energy ray-curable resin composition (non-volatile content: 70%, viscosity: 30 mPa · s).

<Comparative example 3> [Active energy ray-curable resin composition]
70 parts of the composition (A-2) obtained above were mixed with 30 parts of methyl ethyl ketone as a solvent and 2 α-hydroxyalkylphenone photopolymerization initiator (“Irgacure 184” manufactured by BASF) as a photopolymerization initiator. 8 parts was blended to obtain an active energy ray-curable resin composition (non-volatile content: 70%, viscosity: 400 mPa · s).

  About the active energy ray-curable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 3, a cured coating film was formed as follows, and the coating film properties (curl value, scratch resistance, pencil hardness) were determined. evaluated. The evaluation results are shown in Table 1.

[Method for producing sample for evaluation]
The above active energy ray-curable resin composition is coated on a PET film provided with an easy-adhesion layer using a bar coater so that the film thickness after drying is 10 μm, and dried at 60 ° C. for 3 minutes. It was. Then, using a high pressure mercury lamp 80W and one lamp, two passes of UV irradiation (cumulative irradiation amount 500 mJ / cm ² ) are performed at a conveyor speed of 5.1 m / min from a height of 18 cm to form a cured coating film. It was.

[Curl value (lifting height of four corners)]
About the said cured coating film, the sample was cut out to 10 cm x 10 cm square, and it set | placed on the horizontal surface, the average value (mm) of the lifting height of four corners was measured, and it evaluated as follows.
(Evaluation)
◎ (Very good) ... No lift at all ○ (Good) ... With a lift of 1 mm or less △ (Slightly defective) ... With a lift of more than 1 mm and 2 mm or less × (Bad) ... With floats exceeding 2 mm

[Abrasion resistance]
About the said cured coating film, the damage degree of the surface after steel wool # 0000 which applied the load of 500 g was reciprocated 10 times on the cured coating film surface was observed visually, and it evaluated as follows.
(Evaluation)
○ (Good) ・ ・ ・ No scratches △ (Slightly bad) ・ ・ ・ Slightly scratched × (Bad) ・ ・ ・ Thin film is whitened due to scratches

〔Pencil hardness〕
About the said cured coating film, pencil hardness was measured according to JISK5600-5-4.

From the above evaluation results, obtained from the active energy ray-curable resin compositions of Examples 1 to 6 containing a urethane (meth) acrylate-based composition obtained using an acrylic acid adduct of dipentaerythritol having a high hydroxyl value. The resulting cured coating film has a small curl value and is difficult to curl, and has excellent scratch resistance and hardness.
On the other hand, the active energy ray-curable resin composition of Comparative Example 1 containing a urethane (meth) acrylate composition obtained by using an acrylic acid adduct of dipentaerythritol having a small hydroxyl value, a polyfunctional (meth) Obtained from the active energy ray-curable resin composition of Comparative Example 2 that contains only acrylate monomers and does not contain a specific urethane (meth) acrylate-based composition, and the active energy ray-curable resin composition of Comparative Example 3 that does not contain silica It can be seen that the cured coatings to be obtained are both excellent in scratch resistance and hardness, but have a large curl value and easily curl, and are inferior in curling resistance.

The active energy ray-curable resin composition of the present invention forms a cured coating film that has extremely high hardness and scratch resistance when formed, and that is difficult to curl and has excellent substrate adhesion. Therefore, it is useful as a coating agent, particularly as a coating agent for a hard coat or a coating agent for an optical film. It is also useful as a paint or ink.

Claims (7)

  Urethane (meth) acrylate-based composition (A) obtained by reacting (meth) acrylic acid adduct (a) of dipentaerythritol having a hydroxyl value of 60 mgKOH / g or more with polyvalent isocyanate (b), and An active energy ray-curable resin composition comprising silica (B).   The active energy ray-curable resin composition according to claim 1, wherein the viscosity of the urethane (meth) acrylate-based composition (A) is 2,000 to 200,000 mPa · s at 60 ° C.   The active energy ray-curable resin composition according to claim 1, wherein the urethane (meth) acrylate-based composition (A) has a weight average molecular weight of 3,000 to 100,000.   The content ratio (weight ratio) of the urethane (meth) acrylate composition (A) and the silica (B) is (A) :( B) = 30: 70 to 90:10. The active energy ray-curable resin composition according to any one of?   The active energy ray-curable resin composition according to any one of claims 1 to 4, wherein the average particle size of silica (B) is 3 to 100 nm.   The active energy ray-curable resin composition according to any one of claims 1 to 5, wherein the viscosity at 20 ° C is 5 to 50,000 mPa · s. A coating agent comprising the active energy ray-curable resin composition according to claim 1.