JPWO2016002399A1 - Active energy ray-curable resin composition, paint, coating film, and laminated film - Google Patents

Abstract

Active energy ray-curable resin composition, paint containing the resin composition, and paint capable of expressing excellent performance in paint film processability while the cured film obtained has a very high surface hardness And a film having the coating layer. A weight average molecular weight (Mw) formed by connecting a plurality of acrylic polymers (a) having a (meth) acryloyl group in the side chain via a functional group other than the (meth) acryloyl group is 6,000 to 70, An active energy ray-curable resin composition containing a branched acrylic acrylate resin (A) in the range of 000 as an essential component, a paint containing the same, and a coating layer obtained by curing the paint the film.

Description

  The present invention provides an active energy ray-curable resin composition, a paint containing the resin composition, and a paint film comprising the paint, which can obtain a paint film having an extremely high surface hardness and excellent workability. And a laminated film having the coating layer.

  Plastic films produced using polyethylene terephthalate resin (PET), acrylic resin, polycarbonate resin, acetylated cellulose resin and the like are widely used in industrial applications. These films are used as, for example, a polarizing plate protective film or a surface protective film incorporated in a flat panel display, and high scratch resistance is required for these films.

  Various methods have been studied as a method for improving the scratch resistance. However, in recent years, a polyfunctional acrylate having a high crosslinking density is mainly used on the film from the viewpoint of environmental advantages such as reduction of energy required for curing. A method of forming a hard coat layer by applying the active energy ray-curable resin composition and curing with active energy rays such as ultraviolet rays (UV) and electron beams (EB) has been implemented.

  With the progress of lighter and thinner displays, the films used are also made thinner. Therefore, a hard coating agent applied and cured on a film is required to have both higher hardness than before and workability compatible with applications requiring flexibility. Hard coating agents that can be used for such applications include acrylic polymers having a double bond in the side chain, obtained by reacting acrylic acid with an acrylic polymer containing an epoxy group, and polyfunctional acrylates. An active energy ray-curable resin composition obtained by the above is known (for example, see Patent Document 1).

  However, in the active energy ray-curable resin composition comprising an acrylic polymer having a double bond in the side chain and a polyfunctional acrylate provided in Patent Document 1, the reaction of the double bond contained in the composition Due to the insufficient rate, the coating film hardness was still insufficient, although it had a certain workability.

  In addition, the inorganic fine particle dispersed active energy ray curable resin composition obtained by dispersing inorganic fine particles in the resin component has a higher hardness of the cured coating film compared to a resin composition consisting of only an organic material, It is provided as a new material that can be improved in performance and impart new functions such as adjusting the refractive index and imparting conductivity (see, for example, Patent Document 2). A coating film obtained from a resin composition in which such inorganic fine particles are dispersed has a feature of high hardness and can be used as a hard coat layer exhibiting scratch resistance, but is inferior in processability. Therefore, it may be difficult to apply to flexible display applications.

JP 2011-207947 A International Publication WO2013 / 047590

  The problem to be solved by the present invention is that the cured coating film has an extremely high surface hardness and exhibits an excellent workability, and an active energy ray-curable resin composition, and a paint containing the resin composition Another object of the present invention is to provide a coating film comprising the coating material and a laminated film having the coating film layer.

  As a result of intensive studies to solve the above problems, the present inventors have found that a plurality of acrylic polymers (a) having a (meth) acryloyl group in the side chain via a functional group other than the (meth) acryloyl group. An active energy ray-curable resin composition comprising a branched acrylic acrylate resin (A) having a weight average molecular weight (Mw) in the range of 6,000 to 70,000, which is connected, has a very high surface hardness after curing. As a result, the present invention was completed by finding out that it was rich in workability (flexibility) when applied and cured on a plastic substrate.

  That is, the present invention has a weight average molecular weight (Mw) formed by connecting a plurality of acrylic polymers (a) having a (meth) acryloyl group in the side chain via a functional group other than the (meth) acryloyl group. An active energy ray-curable resin composition containing a branched acrylic acrylate resin (A) in the range of 6,000 to 70,000 as an essential component, a paint containing the same, and a cured coating film; And the laminated film which has the said coating film layer is provided.

  According to the present invention, a cured coating film having a very high surface hardness and transparency, and a workability capable of being used as a flexible display, and an active energy ray-curable resin composition capable of providing the cured coating film A paint containing the same can be provided.

  In the active energy ray-curable resin composition of the present invention, the acrylic polymer (a) having a (meth) acryloyl group in the side chain is connected in plural via a functional group other than the (meth) acryloyl group. The branched acrylic acrylate resin (A) having a weight average molecular weight (Mw) in the range of 6,000 to 70,000 is contained as an essential component.

  Since the branched acrylic acrylate resin (A) has a weight average molecular weight (Mw) in the range of 6,000 to 70,000, the cured coating film obtained by curing it has high hardness and workability. Can be granted. From the viewpoint that these effects are more excellent and the viscosity of the active energy ray-curable resin composition is easy to adjust to those suitable for coating, the weight average molecular weight (Mw) is in the range of 8,000 to 50,000. It is preferable that it is in the range of 10,000 to 40,000.

  In the present invention, the weight average molecular weight (Mw) is a value measured under the following conditions using a gel permeation chromatograph (GPC).

Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Tosoh Corporation guard column HXL-H
+ Tosoh Corporation TSKgel G5000HXL
+ Tosoh Corporation TSKgel G4000HXL
+ Tosoh Corporation TSKgel G3000HXL
+ Tosoh Corporation TSKgel G2000HXL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 1.0 ml / min Standard: Polystyrene sample: 0.4 mass% tetrahydrofuran solution filtered in terms of resin solids with a microfilter (100 μl)

  Further, the (meth) acryloyl group equivalent of the branched acrylic acrylate resin (A) is 200 g / eq to 700 g / eq in that a cured coating film having high surface hardness and excellent workability can be easily obtained. The range is preferably 200 g / eq to 550 g / eq.

  The branched acrylic acrylate resin (A) is, for example, an acryl obtained by homopolymerizing a compound having a glycidyl group and a (meth) acryloyl group, or by copolymerizing the compound and a (meth) acrylic ester. An acrylic polymer having a hydroxyl group in the side chain is obtained by reacting a precursor of the polymer with a compound having a carboxyl group and a (meth) acryloyl group, and the reactivity with the hydroxyl group is obtained via this hydroxyl group. It can be obtained by a method of linking a plurality of acrylic polymers using a compound having the same.

  More specifically, first, a homopolymer of a compound having a glycidyl group and a (meth) acryloyl group, or a copolymer of the compound and a (meth) acrylic ester (hereinafter referred to as “precursor (1) The acrylic polymer (a1) obtained by reacting this with a compound having a carboxyl group and a (meth) acryloyl group has two or more isocyanate groups in one molecule. Examples thereof include a resin obtained by reacting the compound (b1). A branched acrylic acrylate resin (A) that can be used in the present invention by reacting a compound (b1) having two or more isocyanate groups in one molecule with a hydroxyl group produced by a reaction between a glycidyl group and a carboxyl group. ) Can be obtained.

  Here, the compound having a glycidyl group and a (meth) acryloyl group as a raw material of the precursor (1) is, for example, glycidyl (meth) acrylate, glycidyl α-ethyl (meth) acrylate, α-n-propyl ( (Meth) acrylic acid glycidyl, α-n-butyl (meth) acrylic acid glycidyl, (meth) acrylic acid-3,4-epoxybutyl, (meth) acrylic acid-4,5-epoxypentyl, (meth) acrylic acid- 6,7-epoxypentyl, α-ethyl (meth) acrylic acid-6,7-epoxypentyl, β-methylglycidyl (meth) acrylate, (meth) acrylic acid-3,4-epoxycyclohexyl, lactone modified (meth) Acrylic acid-3,4-epoxycyclohexyl, vinylcyclohexene oxide and the like can be mentioned. Among these, (meth) acrylic acid glycidyl, α-ethyl (meth) acrylic acid glycidyl, in that it is easy to adjust the (meth) acryloyl group equivalent of the acrylic polymer (a1) to be obtained to a preferred range, And α-n-propyl (meth) acrylate glycidyl are preferably used, and glycidyl (meth) acrylate is more preferably used.

  When the precursor (1) is produced, any of the (meth) acrylic acid esters that can be polymerized with the compound having the glycidyl group and the (meth) acryloyl group can be used. Especially, it becomes easy to adjust the (meth) acryloyl group equivalent of the acrylic polymer (a1) to be obtained within a preferable range of 200 g / eq to 700 g / eq, and an isocyanate group in one molecule. From the viewpoint that a cured coating film obtained by using the branched acrylic acrylate resin (A) obtained by further adding the compound (b1) having two or more compounds can be easily obtained while having high hardness and high workability. (Meth) acrylic acid ester having an alkyl group having 1 to 22 carbon atoms and (meth) acrylic acid ester having an alicyclic alkyl group are preferred. Ku, having an alkyl group of 1 to 22 carbon atoms (meth) acrylic acid ester is more preferable. In particular, it is particularly preferable to use methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and t-butyl (meth) acrylate.

  Here, in order to adjust the (meth) acryloyl group equivalent of the obtained polymer (a1) to a suitable range, the mass ratio of the two at the time of copolymerization [compound having a glycidyl group and a (meth) acryloyl group: It is preferable to use a polymer obtained by copolymerizing (meth) acrylic acid ester] in a ratio of 20/80 to 95/5 as a precursor, and more preferably in a range of 30/70 to 90/10. The range of 60/40 to 90/10 is more preferable, and the range of 80/20 to 90/10 is most preferable.

  The precursor (1) is, for example, a compound having the glycidyl group and the (meth) acryloyl group alone in the temperature range of 60 ° C. to 180 ° C. in the presence of a polymerization initiator, or the compound and (meth). It can be produced by addition polymerization in combination with an acrylic ester. In the case of a copolymer, it may be any of a random copolymer, a block copolymer, a graft copolymer, and the like. As the polymerization method, a bulk polymerization method, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, or the like can be used. Among these, the production of the precursor (1), the subsequent reaction of the precursor (1) with a compound having a carboxyl group and a (meth) acryloyl group, and two isocyanate groups in one molecule The solution polymerization method is preferred in that the reaction with the compound (b1) having the above can be carried out continuously.

  The solvent used when the precursor (1) is produced by the solution polymerization method is preferably a solvent having a boiling point of 80 ° C. or higher in consideration of the reaction temperature. For example, methyl ethyl ketone, methyl-n-propyl ketone, methyl Isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, diethyl ketone, ethyl n-butyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclohexanone, holon, etc. Ketone solvent; ether solvents such as n-butyl ether, diisoamyl ether, dioxane, etc .; acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, acetic acid-n-amyl, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate Esters, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl-3-ethoxypropionate, etc .; toluene, xylene, Solvesso 100, Solvesso 150, Swazol 1800, Swazol 310, Isopar E, Isopar G, Exxon naphtha No. 5, Exxon naphtha No. 6 and other hydrocarbon solvents. These may be used alone or in combination of two or more.

  Among the above solvents, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and ester solvents such as isopropyl acetate and n-butyl acetate are preferred because of the excellent solubility of the resulting precursor (1).

  Examples of the catalyst used in the production of the precursor (1) include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), and 2,2′-. Azo compounds such as azobis- (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, t-butylperoxyethylhexanoate, 1,1'-bis- Examples thereof include organic peroxides such as (t-butylperoxy) cyclohexane, t-amylperoxy-2-ethylhexanoate, and t-hexylperoxy-2-ethylhexanoate, and hydrogen peroxide.

  When using a peroxide as a catalyst, it is good also as a redox type initiator using a peroxide with a reducing agent.

  The precursor (1) thus obtained can be further reacted with a compound having a carboxyl group and a (meth) acryloyl group to obtain an acrylic polymer (a1). In the reaction method, for example, the precursor (1) is polymerized by a solution polymerization method, a compound having a carboxyl group and a (meth) acryloyl group is added to the reaction system, and the temperature range is from 60 ° C to 150 ° C. Examples thereof include a method of appropriately using a catalyst such as triphenylphosphine. The (meth) acryloyl group equivalent of the acrylic polymer (a1) is preferably in the range of 200 eq to 700 g / eq, and this includes the precursor (1), the carboxyl group, and the (meth) acryloyl group. It can adjust with the reaction ratio with the compound which has. Usually, by reacting 1 mol of the glycidyl group of the precursor (1) so that the carboxyl group is in the range of 0.9 to 1.2 mol, the ((1) of the acrylic polymer (a1) obtained) It becomes easy to adjust the (meth) acryloyl equivalent to the preferred range.

  Examples of the compound having a carboxyl group and a (meth) acryloyl group used here include (meth) acrylic acid, (acryloyloxy) acetic acid, 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, and 1- [succinic acid]. Unsaturated monocarboxylic acids such as 2- (acryloyloxy) ethyl], 1- (2-acryloyloxyethyl) phthalate, hydrogen 2- (acryloyloxy) ethyl hexahydrophthalate, and lactone-modified products thereof; maleic acid, etc. Unsaturated dicarboxylic acid: carboxyl group-containing polyfunctional (meth) obtained by reacting acid anhydrides such as succinic anhydride and maleic anhydride with hydroxyl-containing polyfunctional (meth) acrylate monomers such as pentaerythritol triacrylate An acrylate etc. are mentioned. These may be used alone or in combination of two or more. Among these, (meth) acrylic acid, (acryloyloxy) acetic acid, acrylic acid 2 is easy in that the (meth) acryloyl group equivalent of the resulting acrylic polymer (a2) can be easily adjusted to the above-described preferred range. -Carboxyethyl and 3-carboxypropyl acrylate are preferred, and (meth) acrylic acid is particularly preferred.

  The acrylic polymer (a1) thus obtained has a hydroxyl group produced by a reaction between an epoxy group and a carboxyl group in its molecular structure. The branched acrylic acrylate resin (A) used in the present invention can be obtained by further reacting the hydroxyl group and the compound (b1) having two or more isocyanate groups in one molecule.

  Furthermore, from the viewpoint that it can be produced by a method that is easier to synthesize, glycidyl (meth) acrylate is used, and this is copolymerized with (meth) acrylate to obtain precursor (1). ) Is particularly preferably an acrylic polymer (a1) obtained by reacting (meth) acrylic acid.

  The weight average molecular weight of the acrylic polymer (a1) thus obtained is preferably in the range of 3,000 to 15,000. That is, by using the acrylic polymer (a1) within this range, the degree of branching of the obtained branched acrylic acrylate resin (A) becomes appropriate, and the hardness and workability of the resulting cured coating film are expressed in a balanced manner. It becomes easy. From the point of increasing the effect, the weight average molecular weight of the acrylic polymer (a1) is preferably in the range of 4,000 to 13,000, and in the range of 5,000 to 10,000. Is particularly preferred.

  The active energy ray-curable resin composition of the present invention comprises reacting a hydroxyl group in the acrylic polymer (a1) with an isocyanate group in a compound (b1) having two or more isocyanate groups in one molecule. By using the branched acrylic acrylate resin (A) having a branched structure introduced into the resin and having an increased molecular weight distribution width, the surface hardness of the resulting coating film is increased and a urethane bond is included. It is assumed that the processability of the film can be improved. Accordingly, the compound (b1) is not particularly limited as long as it is a compound having two or more isocyanate groups, but the degree of branching is more efficiently increased and the workability of the cured coating film is further expressed. From the point of view, it is preferably a compound having a compound having three or more isocyanate groups in one molecule.

  Examples of the compound (b1) having two or more isocyanate groups in one molecule include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Methyl ester, lysine triisocyanate, m-xylylene diisocyanate, α, α, α ', α'-tetramethylxylylene diisocyanate, bis (isocyanatomethyl) naphthalene, mesitylylene triisocyanate, bis (isocyanatomethyl) sulfide Bis (isocyanatoethyl) sulfide, bis (isocyanatomethyl) disulfide, bis (isocyanatoethyl) disulfide, bis (isocyanatomethylthio) methane, bis (isocyanatoethylthio) methane, Aliphatic polyisocyanate compounds such as bis (isocyanatoethylthio) ethane and bis (isocyanatomethylthio) ethane; isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane isocyanate 2,5-bis (isocyanatomethyl) bicyclo- [2.2.1] -heptane, 2,6-bis (isocyanatomethyl) bicyclo- [2.2.1] -heptane, 3,8-bis (Isocyanatomethyl) tricyclodecane, 3,9-bis (isocyanatomethyl) tricyclodecane, 4,8-bis (isocyanatomethyl) tricyclodecane, 4,9-bis (isocyanatomethyl) trisi Alicyclic polyisocyanate compounds such as lodecane; aromatic polyisocyanate compounds such as diphenyl sulfide-4,4-diisocyanate; 2,5-diisocyanatothiophene, 2,5-bis (isocyanatomethyl) thiophene, 2,5 -Diisocyanatotetrahydrothiophene, 2,5-bis (isocyanatomethyl) tetrahydrothiophene, 3,4-bis (isocyanatomethyl) tetrahydrothiophene, 2,5-diisocyanato-1,4-dithiane, 2,5-bis Heterocyclic polyisocyanate compounds such as (isocyanatomethyl) -1,4-dithiane, 4,5-diisocyanato-1,3-dithiolane, 4,5-bis (isocyanatomethyl) -1,3-dithiolane, and the like Biuret bodies and nurate bodies that are derivatives of isocyanate compounds An allophanate body, a polyol adduct body, etc. can be mentioned, and they may be used alone or in combination of two or more.

  Among these, hexamethylene isocyanate, hexamethylene isocyanate biuret, and hexamethylene isocyanate nurate are used from the viewpoint of excellent processability of the resulting coating film, transparency, and resistance to yellowing. preferable.

  As a use ratio of the compound (b1) having two or more isocyanate groups in one molecule, the weight average molecular weight (Mw) of the obtained branched acrylic acrylate resin (A) is 6,000 to 70,000. It is preferable to use so that it may become a range, It is especially preferable to use so that it may become the range of 8,000-50,000, Furthermore, it is more preferable to use so that it may become the range of 10,000-40,000. Specifically, the compound (B) with respect to 1 mol of the hydroxyl group in the acrylic polymer (a1) having a weight average molecular weight (Mw) having a hydroxyl group and a (meth) acryloyl group in the range of 3,000 to 15,000. ) Is preferably used in an amount of 0.002 to 0.25 mol, particularly preferably 0.01 to 0.18 mol, and more preferably 0.02 to 0.12 mol. It is more preferable to use so that.

  In this reaction, various urethanization reaction catalysts can be used, and the use ratio thereof is about 0.001 to 1.0 part by mass with respect to 100 parts by mass of the acrylic polymer (a1). It is preferable.

  In this urethanization reaction, the organic solvent used in the synthesis of the acrylic polymer (a1) may be used as it is, and the reaction may be performed in the solvent. For example, at a temperature of 40 to 120 ° C., It can be easily obtained by reacting for about 20 hours. Furthermore, you may use together the polymerization inhibitor for suppressing superposition | polymerization of a (meth) acryloyl group.

  In addition, the branched acrylic acrylate resin (A) used in the present invention includes an acrylic polymer (a2) having a glycidyl group-containing weight average molecular weight (Mw) in the range of 2,000 to 14,000, and ( It can also be obtained by reacting a compound (b2) having a (meth) acryloyl group and a carboxyl group with a compound (b3) having two or more carboxyl groups in one molecule.

  Specifically, a homopolymer of a compound having a glycidyl group and a (meth) acryloyl group, or a copolymer of the compound and a (meth) acrylic acid ester (hereinafter referred to as “precursor (2)”) And a compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule and a compound (b3) having two or more carboxyl groups in one molecule are reacted with each other. A reaction for introducing a (meth) acryloyl group into the side chain of the precursor (2) and a reaction for linking a plurality of acrylic polymers (a2) having a (meth) acryloyl group introduced by the reaction are performed.

  Here, examples of the compound having a glycidyl group and a (meth) acryloyl group as raw materials for the precursor (2) include glycidyl (meth) acrylate, glycidyl α-ethyl (meth) acrylate, α-n-propyl ( (Meth) acrylic acid glycidyl, α-n-butyl (meth) acrylic acid glycidyl, (meth) acrylic acid-3,4-epoxybutyl, (meth) acrylic acid-4,5-epoxypentyl, (meth) acrylic acid- 6,7-epoxypentyl, α-ethyl (meth) acrylic acid-6,7-epoxypentyl, β-methylglycidyl (meth) acrylate, (meth) acrylic acid-3,4-epoxycyclohexyl, lactone modified (meth) Acrylic acid-3,4-epoxycyclohexyl, vinylcyclohexene oxide and the like can be mentioned. Among these, glycidyl (meth) acrylate and α-ethyl (meth) are easy in that the (meth) acryloyl group equivalent of the resulting acrylic polymer (a1-2) can be easily adjusted to the above-described preferable range. It is preferable to use glycidyl acrylate and glycidyl α-n-propyl (meth) acrylate, and it is more preferable to use glycidyl (meth) acrylate.

  In producing the precursor (2), any of the (meth) acrylic acid esters that can be polymerized with the compound having the glycidyl group and the (meth) acryloyl group can be used. Among them, it is easy to adjust the (meth) acryloyl group equivalent of the obtained branched acrylic acrylate resin (A) to the above-described preferable range, and the obtained cured coating film is high in hardness and rich in workability. From the viewpoint of easily obtaining a product, (meth) acrylic acid ester having an alkyl group having 1 to 22 carbon atoms and (meth) acrylic acid ester having an alicyclic alkyl group are preferable, and those having 1 to 22 carbon atoms. A (meth) acrylic acid ester having an alkyl group is more preferable. Among others, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (n-butyl) (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, It is particularly preferred to use isobornyl (meth) acrylate.

  Here, it becomes easy to adjust the (meth) acryloyl group equivalent of the obtained branched acrylic acrylate resin (A) to a suitable range, has a high surface hardness, and is excellent in curling resistance during curing. From the point that a film is obtained, the mass ratio of the two at the time of copolymerization [compound having a glycidyl group and a (meth) acryloyl group]: [(meth) acrylic acid ester] is in the range of 20/80 to 95/5. It is preferable to use it in the ratio which becomes, and it is especially more preferable to use it in the ratio used as the range of 30 / 70-95 / 5. Furthermore, it is preferably in the range of 60/40 to 90/10, preferably in the range of 80/20 to 90/10, from the viewpoint of obtaining an active energy ray-curable resin composition that is excellent in curability at a low dose. It is particularly preferred that

  The precursor (2) has an epoxy group derived from a compound having the glycidyl group and a (meth) acryloyl group, and the epoxy equivalent of the precursor (2) is a branched acrylic acrylate resin finally obtained. In terms of easy adjustment of the acryloyl equivalent of (A) to a range of 200 to 700 g / eq, the range is preferably 140 to 720 g / eq, and more preferably 150 to 480 g / eq. Preferably, it is in the range of 150 to 240 g / eq, more preferably in the range of 150 to 180 g / eq.

  The precursor (2) is, for example, a compound having the glycidyl group and the (meth) acryloyl group alone in the temperature range of 60 ° C. to 180 ° C. in the presence of a polymerization initiator, or the (meth) acrylic acid. Although it can manufacture by superposing | polymerizing using ester together, manufacture of the said precursor (2), the said precursor (2) following this, (meth) acryloyl group, and a carboxyl group in 1 molecule It is preferable to produce by solution polymerization in that the reaction of the compound (b2) having a azo group and the compound (b3) having two or more carboxyl groups in one molecule can be carried out continuously.

  The solvent used when the precursor (2) is produced by solution polymerization is preferably a solvent having a boiling point of 80 ° C. or higher in consideration of the reaction temperature. For example, methyl ethyl ketone, methyl-n-propyl ketone, methyl Isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, diethyl ketone, ethyl n-butyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclohexanone, holon, etc. Ketone solvent; ether solvents such as n-butyl ether, diisoamyl ether, dioxane; ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol Monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether , Propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether Glycol ether solvents such as tellurium; acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, acetic acid-n-amyl, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Ester solvents such as propylene glycol monomethyl ether acetate and ethyl-3-ethoxypropionate; isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, diacetone alcohol, 3-methoxy-1-propanol, 3-methoxy-1-butanol Alcohol solvents such as 3-methyl-3-methoxybutanol; toluene, xylene, Solvesso 100, Solvesso 150, Examples thereof include hydrocarbon solvents such as Swazol 1800, Swazol 310, Isopar E, Isopar G, Exxon Naphtha 5 and Exxon Naphtha 6. These may be used alone or in combination of two or more.

  Among the solvents, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and ester solvents such as isopropyl acetate and n-butyl acetate are preferable from the viewpoint of excellent solubility of the obtained precursor (2).

  Examples of the catalyst used in the production of the precursor (2) include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), and 2,2′-azobis. Azo compounds such as-(4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, t-butylperoxyethylhexanoate, 1,1'-bis- ( organic peroxides such as (t-butylperoxy) cyclohexane, t-amylperoxy-2-ethylhexanoate, and t-hexylperoxy-2-ethylhexanoate, and hydrogen peroxide.

  When using a peroxide as a catalyst, it is good also as a redox type initiator using a peroxide with a reducing agent.

  The precursor (2) thus obtained has a weight average molecular weight in the range of 2,000 to 14,000, and is obtained by the subsequent reaction with the compounds (b2) and (b3). The molecular weight of the branched acrylic acrylate resin (A) is preferable in that it can be easily prepared in the range of 6,000 to 70,000.

  Next, a compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule and a compound (b3) having two or more carboxyl groups in one molecule are reacted with the precursor (2). In the reaction method, for example, the precursor (2) is polymerized by a solution polymerization method, the compounds (b2) and (b3) are added to the reaction system, and a temperature range of 60 to 150 ° C. is used, such as triphenylphosphine. Examples thereof include a method of appropriately using a catalyst. The branched acrylic acrylate resin (A) to be obtained preferably has a (meth) acryloyl group equivalent in the range of 200 to 700 g / eq. This is because the precursor (2) and (meth) in one molecule are included. It can be adjusted by the use ratio of the compound (b2) having an acryloyl group and a carboxyl group and the compound (b3) having two or more carboxyl groups in one molecule. Usually, the carboxyl group in the compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule and a carboxyl group in one molecule with respect to 1 mol of the glycidyl group of the precursor (2). It is preferably used so that the total number of moles of the carboxyl groups in the compound (b3) having two or more is 0.9 to 1.2 moles, particularly 0.95 to 1.1 moles. Is preferred.

  In the reaction, the proportion of the compounds (b2) and (b3) used is (b3) / (b2) (moles) in view of the degree of branching and the weight average molecular weight of the resulting branched acrylic acrylate resin (A). Ratio) of 0.3 / 99.7 to 30/70, preferably 1/99 to 20/80, and more preferably 5/95 to 12/88. It is more preferable to use in.

  The compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule used here is, for example, (meth) acrylic acid, (acryloyloxy) acetic acid, 2-carboxyethyl acrylate, 3-carboxy acrylate. Unsaturation of propyl, succinic acid 1- [2- (acryloyloxy) ethyl], 1- (2-acryloyloxyethyl) phthalate, hydrogen 2- (acryloyloxy) ethyl hexahydrophthalate, and lactone-modified products thereof Monocarboxylic acids; unsaturated dicarboxylic acids such as maleic acid; carboxyls obtained by reacting acid anhydrides such as succinic anhydride and maleic anhydride with hydroxyl-containing polyfunctional (meth) acrylate monomers such as pentaerythritol triacrylate And group-containing polyfunctional (meth) acrylates. These may be used alone or in combination of two or more. Among these, (meth) acrylic acid, (acryloyloxy) acetic acid, acrylic are easy in that the (meth) acryloyl group equivalent of the obtained branched acrylic acrylate resin (A) can be easily adjusted to the above-mentioned preferable range. Acid 2-carboxyethyl and 3-carboxypropyl acrylate are preferred, and (meth) acrylic acid is particularly preferred.

  Examples of the compound (b3) having two or more carboxyl groups in one molecule include oxalic acid, malonic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, chlorinated maleic acid, and het acid. Aliphatic carboxylic acids having 2 to 50 carbon atoms such as succinic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, 2,4-diethylglutaric acid, decamethylenedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, Aromatic dicarboxylic acids such as dichlorophthalic acid, dichloroisophthalic acid, tetrachlorophthalic acid, tetrachloroisophthalic acid, tetrachloroterephthalic acid; tetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, hexahydroisophthalic acid, hexa Alicyclic dicarboxylic acids such as hydroterephthalic acid, Such as Ma acid, and the like.

  Furthermore, the half ester body of dicarboxylic acid obtained by addition reaction of 1 mol of diol and 2 mol of acid anhydride can be used. Examples of such diols include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1, 6-hexanediol, pentanediol, dimethylbutanediol, hydrogenated bisphenol A, bisphenol A, neopentyl glycol, 1,8-octanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-methyl- 1,3-propanediol and the like can be mentioned. Examples of the acid anhydride used in the half ester body include succinic acid, glutaric acid, 2,4-diethylglutaric acid, phthalic acid, maleic acid, dichlorophthalic acid, tetrachlorophthalic acid, tetrahydrophthalic acid, hexahydro Examples thereof include acid anhydrides of dicarboxylic acids such as phthalic acid and methylhexahydrophthalic acid. In addition, any compound having a dicarboxylic acid structure such as a terminal dicarboxylic acid having a polyester structure or a polybutadiene structure may be used.

  Examples of the tricarboxylic acid compound include propane-1,2,3-tricarboxylic acid, propene-1,2,3-tricarboxylic acid, butane-1,2,3-tricarboxylic acid, pentane-1,2,3-tricarboxylic acid. Acid, aliphatic tricarboxylic acid having 2 to 50 carbon atoms such as hexane-1,2,3-tricarboxylic acid; 1,3,5-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5 -Aromatic tricarboxylic acids such as benzene triacetic acid; and alicyclic tricarboxylic acids such as 1,3,5-cyclohexanetricarboxylic acid and 1,2,4-cyclohexanetricarboxylic acid.

  Instead of this tricarboxylic acid, a half ester of tricarboxylic acid obtained by addition reaction of 1 mol of triol and 3 mol of acid anhydride can be used. Examples of such triols include glycerin, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,7-heptanetriol, 1,2 , 8-octanetriol, 1,2,9-nonanetriol, 1,2,10-decanetriol, 1,3,5-cyclohexanetriol, 1,2,4-cyclohexanetriol, 1,3,5-benzenetriol 1,2,4-benzenetriol, 2,6-bis (hydroxymethyl) -4-cresol, trimethylolpropane, trimethylolethane and the like. Examples of the acid anhydride used in the half ester body include succinic acid, glutaric acid, phthalic acid, maleic acid, dichlorophthalic acid, tetrachlorophthalic acid, tetrahydrophthalic acid, and hexahydrophthalic acid methylhexahydrophthalic acid. Of the acid anhydride.

  Examples of the tetracarboxylic acid compound include aliphatic tetracarboxylic acids having 2 to 50 carbon atoms such as 1,2,3,4-butanetetracarboxylic acid; aromatic tetracarboxylic acids such as benzenetetracarboxylic acid; cyclohexanetetracarboxylic And alicyclic tetracarboxylic acids such as acids.

  Moreover, the tetracarboxylic acid half ester body obtained by addition reaction with 1 mol tetraol and 4 mol acid anhydride can be used instead of this tetracarboxylic acid. Examples of such a tetraol include pentaerythritol. Examples of acid anhydrides used in the half ester form include succinic acid, glutaric acid, phthalic acid, maleic acid, dichlorophthalic acid, tetrachlorophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and methylhexahydrophthalic acid. And acid anhydrides. In addition, any compound having a tetracarboxylic acid structure can be used. The raw materials for these tetracarboxylic acid type compounds may be used alone or in combination of two or more. Among the tetracarboxylic acids, pentaerythritol and methylhexahydrophthalic anhydride are more preferable. Further, examples of the compound having 5 or more functional groups include, for example, a half ester of ditrimethylolpropane with dicarboxylic acid (pentafunctional), a half ester of dipentaerythritol with dicarboxylic acid (hexafunctional), and further five functionals. The half ester (polyfunctionality) with the dicarboxylic acid of the above polyol is mentioned.

  In this reaction, a reaction catalyst such as triphenylphosphine can be used, and the use ratio thereof is about 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the acrylic polymer (a1). It is preferable.

  In this reaction, the organic solvent used in the synthesis of the precursor (2) may be used as it is, and the reaction may be performed in the solvent. For example, the reaction is performed at a temperature of 80 to 130 ° C. for 1 to 20 hours. By making it, it can obtain easily. Furthermore, you may use together the polymerization inhibitor for suppressing superposition | polymerization of a (meth) acryloyl group.

  Among the production methods of the branched acrylic acrylate resin (A) described above, it is preferable to use the precursor (1) from the viewpoint of easier synthesis, and in particular, using glycidyl (meth) acrylate, This is copolymerized with a (meth) acrylic acid ester to obtain a precursor (1), and the precursor (1) is reacted with (meth) acrylic acid to obtain an acrylic polymer (a). A branched acrylic acrylate resin obtained by reacting an isocyanate biuret is particularly preferable.

  Further, in the present invention, from the viewpoint of easy preparation of the viscosity as a paint and good curability and the viewpoint of increasing the surface hardness of the obtained coating film, other than the branched acrylic acrylate resin (A) (Meth) acrylate (C) may be used in combination.

  The (meth) acrylate that can be used in the present application is not particularly limited, and examples thereof include various (meth) acrylate monomers and urethane (meth) acrylate.

  Examples of the (meth) acrylate monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) ) Acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate Relate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phosphoric acid (meth) acrylate, ethylene oxide modified phosphoric acid (meth) acrylate, phenoxy (meth) acrylate , Ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, Methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, 2- (Meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen phthalate, 2- ( (Meth) acryloyloxypropyl hexahydrohydrogen phthalate, 2- (meth) acryloyloxypropyl tetrahydrophthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl ( (Meth) acrylate, octafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, adamantyl Mono (meth) acrylates such as mono (meth) acrylate;

  Butanediol di (meth) acrylate, hexanediol di (meth) acrylate, ethoxylated hexanediol di (meth) acrylate, propoxylated hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate , Di (meth) acrylates such as polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate;

  Trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, tris 2-hydroxyethyl isocyanurate tri (meth) acrylate, glycerin tri (meth) acrylate Tri (meth) acrylates such as;

  Pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) Tetrafunctional or higher functional (meth) acrylates such as acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylylpropane hexa (meth) acrylate;

  And the (meth) acrylate etc. which substituted a part of above-mentioned various polyfunctional (meth) acrylate by the alkyl group etc. are mentioned.

  Examples of the urethane (meth) acrylate include urethane (meth) acrylate obtained by reacting a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate compound.

  Examples of the polyisocyanate compound used as a raw material for the urethane (meth) acrylate include various diisocyanate monomers and a nurate polyisocyanate compound having an isocyanurate ring structure in the molecule.

  Examples of the diisocyanate monomer include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene. Aliphatic diisocyanates such as range isocyanate;

  Cycloaliphatic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate;

  1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate And aromatic diisocyanates such as 1,4-phenylene diisocyanate and tolylene diisocyanate.

  Examples of the nurate type polyisocyanate compound having an isocyanurate ring structure in the molecule include those obtained by reacting a diisocyanate monomer with a monoalcohol and / or a diol. Examples of the diisocyanate monomer used in the reaction include the various diisocyanate monomers described above, and each may be used alone or in combination of two or more. Monoalcohols used in the reaction are hexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-heptadecanol, n- Octadecanol, n-nonadecanol and the like can be mentioned, and the diol includes ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1, Examples include 3-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. These monoalcohols and diols may be used alone or in combination of two or more.

  Among these polyisocyanate compounds, the diisocyanate monomer is preferable, and the aliphatic diisocyanate and the alicyclic diisocyanate are more preferable in that a cured coating film having excellent processability can be obtained.

  The hydroxyl group-containing (meth) acrylate compound used as a raw material for the urethane (meth) acrylate is, for example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, glycerin diacrylate, trimethylolpropane diacrylate, Aliphatic (meth) acrylate compounds such as pentaerythritol triacrylate and dipentaerythritol pentaacrylate;

  4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, 1-phenyl-2-hydroxyethyl acrylate, 3-hydroxy-4-acetylphenyl acrylate, 2-hydroxy-3-phenoxy Examples include (meth) acrylate compounds having an aromatic ring in the molecular structure such as propyl acrylate. These may be used alone or in combination of two or more.

  Among these hydroxyl (meth) acrylate compounds, glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentane are obtained because a cured coating film having excellent processability and high surface hardness can be obtained. An aliphatic (meth) acrylate compound having two or more (meth) acryloyl groups in the molecular structure such as acrylate is preferred. Furthermore, an aliphatic (meth) acrylate compound having three or more (meth) acryloyl groups in the molecular structure such as pentaerythritol triacrylate and dipentaerythritol pentaacrylate in that a cured coating film having higher surface hardness can be obtained. Is more preferable.

  The method for producing the urethane (meth) acrylate includes, for example, the polyisocyanate compound, the hydroxyl group-containing (meth) acrylate compound, the isocyanate group of the polyisocyanate compound, and the hydroxyl group-containing (meth) acrylate compound. The molar ratio [(NCO) / (OH)] with the hydroxyl group to be used is within a range of 1 / 0.95 to 1 / 1.05, within a temperature range of 20 to 120 ° C., if necessary. Examples of the method include using various urethanization catalysts.

  When the urethane (meth) acrylate is produced from the polyisocyanate compound and the (meth) acrylate compound having one hydroxyl group in the molecular structure, the reaction is pentaerythritol tetra (meth) acrylate or dipentaerythritol hexa You may carry out by the type | system | group containing acrylate compounds, such as (meth) acrylate. Specifically, the urethane (meth) acrylate obtained by such a method is obtained by reacting a raw material containing the polyisocyanate compound, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. Examples thereof include urethane (meth) acrylate obtained, urethane acrylate obtained by reacting a raw material containing polyisocyanate compound, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. .

  The weight average molecular weight (Mw) of the urethane (meth) acrylate thus obtained is preferably in the range of 800 to 20,000 in terms of excellent compatibility with the branched acrylic acrylate resin (A). More preferably, it is in the range of 900 to 1,000.

  These compounds (C) may be used alone or in combination of two or more. Among them, a polyfunctional (meth) acrylate having 3 or more (meth) acryloyl groups in one molecule is preferable because a coating film with higher hardness can be obtained. Examples of the polyfunctional (meth) acrylate having three or more (meth) acryloyl groups include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa. (Meth) acrylate is preferred. Moreover, as urethane (meth) acrylate as polyfunctional (meth) acrylate having three or more (meth) acryloyl groups, diisocyanate compound, glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipenta Urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate compound having two or more (meth) acryloyl groups in the molecular structure such as erythritol pentaacrylate is preferred, and the diisocyanate compound and (meth) acryloyl group are A urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate compound having three or more is more preferable.

  The (meth) acrylate (C) that can be used in the present invention may be a multi-branched (meth) acrylate. As such a multi-branched (meth) acrylate, any of those provided with names such as dendrimer, core-shell, hyperbranch and the like can be used, for example, WO08 / 047620, JP What is provided with the manufacturing method in 2012-111963 gazette, Japanese translations of PCT publication No. 10-508052 gazette, etc. can use all suitably. Moreover, as what is marketed as such a multi-branched (meth) acrylate, SIRIUS501 etc. by Osaka Organic Chemical Co., Ltd. are mentioned.

  In the present invention, the use ratio of the branched acrylic acrylate resin (A) and the other (meth) acrylate (C) is not particularly limited, and the hardness and workability of the desired cured coating film are not particularly limited. Furthermore, although it can be appropriately set in view of transparency and scratch resistance, the branched acrylic acrylate resin (from the viewpoint of easily obtaining a coating film having particularly high surface hardness and good processability) The mass ratio (A) / (C) between A) and (meth) acrylate (C) is preferably in the range of 10/90 to 100/0, particularly in the range of 30/70 to 90/10. It is preferable that the ratio is 60/40 to 80/20.

  In the present invention, inorganic fine particles (D) can be used in combination for the purpose of further increasing the surface hardness of the coating film and imparting other performances such as anti-blocking properties.

  The blending ratio of the inorganic fine particles (D) can be appropriately set according to the intended performance. From the point of obtaining a highly transparent cured coating film, the active energy ray-curable resin composition contains It is preferable to contain inorganic fine particles (D) in the range of 30 to 55 parts by mass with respect to 100 parts by mass of the nonvolatile content. That is, when the content of the inorganic fine particles (D) is 30 parts by mass or more, the effect of improving the hardness at the time of curing and the scratch resistance becomes remarkable. Moreover, when content of the said inorganic fine particle (D) is 55 mass parts or less, the storage stability and transparency of an active energy ray hardening-type resin composition will become favorable. Among them, the resin composition is excellent in storage stability, and a cured coating film having both high surface hardness, transparency, and curl resistance can be obtained, with respect to 100 parts by mass of the nonvolatile content in the composition. More preferably, the inorganic fine particles (D) are contained in the range of 35 to 50 parts by mass.

  The average particle diameter of the inorganic fine particles (D) is in the range of 95 to 250 nm as a value measured by a dynamic light scattering method in a state of being dispersed in the composition, and the surface hardness and transparency of the coating film. From the point which is excellent in balance with property. That is, when the average particle diameter is 95 nm or more, the surface hardness of the obtained coating film is further increased. On the other hand, when it is 250 nm or less, the resulting coating film has good transparency. Especially, it is more preferable that the average particle diameter is in the range of 100 to 130 nm in that the hardness and transparency of the obtained coating film can be combined at a higher level.

  In the present invention, the average particle diameter of the inorganic fine particles (D) measured by the dynamic light scattering method is measured according to “ISO 13321” and calculated by the cumulant method. The active energy ray-curable resin composition is diluted with MIBK to prepare a MIBK solution having a concentration of 1.0%, and then this MIBK solution is used to measure a particle size (“ELSZ-2” manufactured by Otsuka Electronics Co., Ltd.). Is a measured value.

  Specific examples of the inorganic fine particles (D) used here include inorganic fine particles such as silica, alumina, zirconia, titania, barium titanate, and antimony trioxide. These may be used alone or in combination of two or more. Among these inorganic fine particles (D), silica fine particles are preferable because they are easily available and easy to handle. Examples of the silica fine particles include wet silica and dry silica. Examples of the wet silica include so-called precipitated silica or gel silica obtained by reacting sodium silicate with a mineral acid. Moreover, when using such wet silica, the average particle size of the inorganic fine particles dispersed in the resin composition finally obtained is that the average particle size in the dry state is 95 to 250 nm. It is preferable in that it is easy to adjust to a preferable value.

  On the other hand, dry silica fine particles are obtained, for example, by burning silicon tetrachloride in an oxygen or hydrogen flame, and have an average primary particle size of 3 to 100 nm, particularly 5 to 50 nm, before being dispersed. It is easy to adjust the average particle diameter of the inorganic fine particles (D) in the finally obtained resin composition to the above-mentioned range of 95 to 250 nm, being secondary particles in which the dry silica fine particles in the range are aggregated. It is preferable from the point which becomes.

  Among the above-mentioned silica fine particles, dry silica fine particles are preferable in that a cured coating film having higher surface hardness can be obtained.

  In the present invention, the inorganic fine particles (D) may be those obtained by introducing reactive functional groups on the surface of the inorganic fine particles using a silane coupling agent to the various inorganic fine particles described above. By introducing a reactive functional group on the surface of the inorganic fine particles (D), the miscibility with the organic component such as the branched acrylic acrylate resin (A) and other (meth) acrylate (C) is increased, and dispersion stability is improved. And storage stability are improved.

  Examples of the silane coupling agent used here include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxy Propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- ( Minoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl- N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, special Aminosilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanate group Pyrtriethoxysilane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, etc. , Vinyl silane coupling agents;

  Diethoxy (glycidyloxypropyl) methylsilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-bridoxypropyl Epoxy-based silane coupling agents such as triethoxysilane;

  styrenic silane coupling agents such as p-styryltrimethoxysilane;

  3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. (meth) Acryloxy silane coupling agent;

  N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltri Amino-based silane couplings such as methoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane Agent;

  Ureido-based silane coupling agents such as 3-ureidopropyltriethoxysilane;

  Chloropropyl-based silane coupling agents such as 3-chloropropyltrimethoxysilane;

  Mercaptopropyl silane coupling agents, such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethinesilane;

  Sulfide-based silane coupling agents such as bis (triethoxysilylpropyl) tetrasulfide;

  Examples thereof include isocyanate-based silane coupling agents such as 3-isocyanatopropyltriethoxysilane. These silane coupling agents may be used alone or in combination of two or more. Among these, a (meth) acryloxy-based silane coupling agent is preferable in that a cured coating film having excellent miscibility with an organic component, high surface hardness, and excellent transparency is obtained, and 3-acryloxypropyltrimethyl is preferred. Methoxysilane and 3-methacryloxypropyltrimethoxysilane are more preferable.

  The resin composition of the present invention may contain a dispersion aid as necessary. Examples of the dispersion aid include phosphate ester compounds such as isopropyl acid phosphate, triisodecyl phosphite, ethylene oxide-modified phosphate dimethacrylate, and the like. These may be used alone or in combination of two or more. Among these, ethylene oxide-modified phosphoric dimethacrylate is preferable because it is excellent in dispersion assist performance.

  Examples of commercially available dispersion aids include “Kayamar PM-21” and “Kayamer PM-2” manufactured by Nippon Kayaku Co., Ltd., “Light Ester P-2M” manufactured by Kyoeisha Chemical Co., Ltd., and the like.

  When using the said dispersion | distribution adjuvant, it contains in 0.5-5.0 mass parts in 100 mass parts of resin compositions of this invention at the point used as a resin composition with higher storage stability. Is preferred.

  Moreover, the resin composition of this invention may contain the organic solvent. For example, when the branched acrylic acrylate resin (A) is produced by a solution polymerization method, the organic solvent may contain the solvent used at that time as it is, or further add another solvent. It may be added. Or you may remove the organic solvent used at the time of manufacture of the said branched acrylic acrylate resin (A) once, and use another solvent. Specific examples of solvents used include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; cyclic ether solvents such as tetrahydrofuran and dioxolane; esters such as methyl acetate, ethyl acetate, and butyl acetate; aromatic solvents such as toluene and xylene; Examples include alcohol solvents such as Tol, Cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether; and glycol ether solvents such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monopropyl ether. These may be used alone or in combination of two or more. Among these, a ketone solvent is preferable and methyl isobutyl ketone is more preferable in that the resin composition has excellent storage stability and excellent paintability when used as a paint.

  The resin composition of the present invention further comprises an ultraviolet absorber, an antioxidant, a silicon-based additive, organic beads, a fluorine-based additive, a rheology control agent, a defoaming agent, a release agent, an antistatic agent, and an antifogging agent. Further, additives such as a colorant, an organic solvent, and an inorganic filler may be contained.

  Examples of the ultraviolet absorber include 2- [4-{(2-hydroxy-3-dodecyloxypropyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1, 3,5-triazine, 2- [4-{(2-hydroxy-3-tridecyloxypropyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3 Triazine derivatives such as 2,5-triazine, 2- (2'-xanthenecarboxy-5'-methylphenyl) benzotriazole, 2- (2'-o-nitrobenzyloxy-5'-methylphenyl) benzotriazole, 2- Xanthenecarboxy-4-dodecyloxybenzophenone, 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone, and the like.

  Examples of the antioxidant include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, and phosphate ester-based antioxidants. These may be used alone or in combination of two or more.

  Examples of the silicon-based additive include dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, and fluorine-modified dimethyl. Examples include polyorganosiloxanes having alkyl groups and phenyl groups, such as polysiloxane copolymers and amino-modified dimethylpolysiloxane copolymers, polydimethylsiloxanes having polyether-modified acrylic groups, and polydimethylsiloxanes having polyester-modified acrylic groups. It is done. These may be used alone or in combination of two or more.

  Examples of the organic beads include polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacryl styrene beads, silicone beads, glass beads, acrylic beads, benzoguanamine resin beads, melamine resin beads, polyolefin resin beads, Examples thereof include polyester resin beads, polyamide resin beads, polyimide resin beads, polyfluorinated ethylene resin beads, and polyethylene resin beads. The preferable value of the average particle diameter of these organic beads is in the range of 1 to 10 μm. These may be used alone or in combination of two or more.

  Examples of the fluorine-based additive include DIC Corporation “Megafac” series. These may be used alone or in combination of two or more.

  Examples of the release agent include “Tegorad 2200N”, “Tegorad 2300”, “Tegorad 2100” manufactured by Evonik Degussa, “UV3500” manufactured by BYK Chemie, “Paintad 8526” manufactured by Toray Dow Corning, and “SH-29PA”. Or the like. These may be used alone or in combination of two or more.

  Examples of the antistatic agent include pyridinium, imidazolium, phosphonium, ammonium, or lithium salts of bis (trifluoromethanesulfonyl) imide or bis (fluorosulfonyl) imide. These may be used alone or in combination of two or more.

  The amount of the various additives used is preferably in a range where the effect is sufficiently exhibited and ultraviolet curing is not inhibited. Specifically, in each 100 parts by mass of the resin composition of the present invention, 0.01 to 40 masses are used. It is preferable to use within the range of parts.

  The resin composition of the present invention preferably further contains a photopolymerization initiator. Examples of the photopolymerization initiator include benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4,4′-bisdimethylaminobenzophenone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichlorobenzophenone, Various benzophenones such as Michler's ketone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone;

  Xanthones, thioxanthones such as xanthone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone; various acyloin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether;

  Α-diketones such as benzyl and diacetyl; sulfides such as tetramethylthiuram disulfide and p-tolyl disulfide; various benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate;

  3,3′-carbonyl-bis (7-diethylamino) coumarin, 1-hydroxycyclohexyl phenyl ketone, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-hydroxy-2-methyl-1- Phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 1- [4- (2-hydroxyethoxy) phenyl] -2- Hydroxy-2-methyl-1-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2- Tylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4'-methyldimethylsulfide, 2,2'-diethoxyacetophenone, benzyldimethyl Ketal, benzyl-β-methoxyethyl acetal, methyl o-benzoylbenzoate, bis (4-dimethylaminophenyl) ketone, p-dimethylaminoacetophenone, α, α-dichloro-4-phenoxyacetophenone, pentyl-4- Dimethylaminobenzoate, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer, 2,4-bis-trichloromethyl-6- [di- (ethoxycarbonylmethyl) amino] phenyl-S-triazine, 2 , 4-Bis-trichloromethyl-6- (4-ethoxy Phenyl-S-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-ethoxy) phenyl-S-triazineanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, etc. Is mentioned. These may be used alone or in combination of two or more.

  Among the photopolymerization initiators, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy- 2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2 , 4,6-trimethylbenzoyl) phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholino One or more mixed systems selected from the group of phenyl) -butan-1-one By are more active against a broad range of wavelengths of light is preferred because highly curable coating is obtained.

  Commercially available products of the photopolymerization initiator include, for example, “Irgacure-184”, “Irgacure-149”, “Irgacure-261”, “Irgacure-369”, “Irgacure-500”, “Irgacure-” manufactured by Ciba Specialty Chemicals. "Irgacure-754", "Irgacure-784", "Irgacure-819", "Irgacure-907", "Irgacure-1116", "Irgacure-1664", "Irgacure-1700", "Irgacure-1800" "Irgacure-1850", "Irgacure-2959", "Irgacure-4043", "Darocur-1173"; "Lucirin TPO" manufactured by BASF; "Kayacure-DETX", "Kayacure-MBP" manufactured by Nippon Kayaku Co., Ltd. ”,“ Kayaki “A-DMBI”, “Kayacure-EPA”, “Kayacure-OA”; “Bicure-10”, “Bicure-55” manufactured by Stowa Chemical Co., Ltd. “Trigonal P1” manufactured by Akzo Co., Ltd .; “Sandray 1000” manufactured by Sands Co .; “Deep” manufactured by Apjon; “QuantaCure-PDO”, “QuantaCure-ITX”, “QuantaCure-EPD”, etc. manufactured by Ward Brenkinsop.

  The amount of the photopolymerization initiator used is an amount that can sufficiently exhibit the function as a photopolymerization initiator, and is preferably within a range that does not cause precipitation of crystals and physical properties of the coating film. It is preferable to use in the range of 0.05 to 20 parts by mass with respect to 100 parts by mass of the resin composition, and it is particularly preferable to use in the range of 0.1 to 10 parts by mass.

  The resin composition of the present invention may further use various photosensitizers in combination with the photopolymerization initiator. Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds.

  In the present invention, a thermal polymerization initiator can also be used. Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-). Azo compounds such as 2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, t-butylperoxyethylhexanoate, 1,1′-bis- (t-butylperoxy) cyclohexane , Organic peroxides such as t-amylperoxy-2-ethylhexanoate and t-hexylperoxy-2-ethylhexanoate, hydrogen peroxide, and the like. It is preferably used in the range of 0.05 to 20 parts by mass.

  The method for producing the active energy ray-curable resin composition of the present invention includes, for example, a disperser, a disperser having a stirring blade such as a turbine blade, a paint shaker, a roll mill, a ball mill, an attritor when the inorganic fine particles (D) are used in combination. A method of mixing and dispersing the inorganic fine particles (D) in the branched acrylic acrylate resin (A) using a dispersing machine such as a sand mill, a bead mill, or the branched fine acrylic acrylate resin. (A) and the method of mixing and dispersing in the resin component which consists of said (meth) acrylate (C) are mentioned. When the inorganic fine particles (D) are wet silica fine particles, a uniform and stable dispersion can be obtained when any of the above-described dispersers is used. On the other hand, when the inorganic fine particles (C) are dry silica fine particles, it is preferable to use a ball mill or a bead mill in order to obtain a uniform and stable dispersion.

  The ball mill that can be preferably used in producing the active energy ray-curable resin composition of the present invention has, for example, a vessel filled with a medium inside, a rotating shaft, and a rotating shaft coaxial with the rotating shaft. A stirring blade that is rotated by the rotational drive of the rotating shaft, a raw material supply port installed in the vessel, a dispersion outlet installed in the vessel, and a portion where the rotating shaft passes through the vessel. The shaft seal device has a structure in which the shaft seal device has two mechanical seal units, and the seal portions of the two mechanical seal units are sealed with an external seal liquid. A wet ball mill is mentioned.

  That is, a method for producing an active energy ray-curable resin composition containing inorganic fine particles (D) includes, for example, a vessel filled with media inside, a rotating shaft, and a rotating shaft coaxial with the rotating shaft. A stirring blade that is rotated by the rotational drive of the rotating shaft, a raw material supply port installed in the vessel, a dispersion outlet installed in the vessel, and a portion where the rotating shaft passes through the vessel. A wet ball mill having a shaft seal device, wherein the shaft seal device has two mechanical seal units, and the seal portions of the two mechanical seal units are sealed with an external seal liquid. Components of the inorganic fine particles (D), the resin (A), and the (meth) acrylate (C) are supplied from the supply port of the wet ball mill as an apparatus. The resin component is supplied to the vessel, and the rotating shaft and the stirring blade are rotated in the vessel to stir and mix the medium and the raw material, whereby the inorganic fine particles (D) are pulverized and the inorganic fine particles ( D) is dispersed in the resin component, and then discharged from the discharge port.

  The active energy ray-curable resin composition of the present invention can be used for coating applications. The coating material can be used as a coating layer that protects the surface of the substrate by applying the coating onto various substrates and irradiating and curing the active energy rays. In this case, the coating material of the present invention may be directly applied to the surface protection member, or a material applied on a plastic film may be used as the protective film. Or you may use what applied the coating material of this invention on the plastic film, and formed the coating film as optical films, such as an antireflection film, a diffusion film, and a prism sheet. The coating film obtained using the paint of the present invention is characterized by high surface hardness and excellent transparency, so it can be applied to various types of plastic film with a film thickness according to the application, and used as a protective film or film It can be used as a molded product.

  Furthermore, in order to obtain a coating film, a heat treatment step can be included before or after irradiation with active energy rays. By performing the heat treatment, a coating film with higher hardness can be obtained. The heating temperature at this time can be appropriately selected depending on the heat resistance of the substrate (plastic film) to be used, but from the viewpoint of further increasing the surface hardness, it is in the range of 80 to 200 ° C. and 1 to 180. It is preferable to perform processing for about a minute.

  The plastic film is, for example, a plastic film made of polycarbonate, polymethyl methacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine resin, triacetyl cellulose resin, ABS resin, AS resin, norbornene resin, cyclic olefin, polyimide resin, or the like. And plastic sheets.

  Among the plastic films, the triacetyl cellulose film is a film that is particularly suitably used for the polarizing plate application of a liquid crystal display. However, since the thickness is generally as thin as 40 to 100 μm, the surface even when a hard coat layer is installed. It is difficult to make the hardness sufficiently high, and there is a feature that it is easily curled. The coating film made of the resin composition of the present invention has a high surface hardness, excellent curl resistance, workability, and transparency even when a triacetyl cellulose film is used as a base material. Can be used. When the triacetyl cellulose film is used as a substrate, the coating amount when applying the coating material of the present invention is applied so that the film thickness after drying is in the range of 1 to 20 μm, preferably in the range of 2 to 15 μm. It is preferable. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, and screen printing.

  Among the plastic films, examples of the polyester film include polyethylene terephthalate, and the thickness thereof is generally about 100 to 300 μm. Although it is a cheap and easy to process film, it is a film used for various applications such as a touch panel display. However, it is very soft and has a feature that it is difficult to sufficiently increase the surface hardness even when a hard coat layer is provided. When the polyethylene film is used as a substrate, the coating amount when applying the coating material of the present invention is in the range of 5 to 100 μm, preferably 7 to 80 μm after drying, depending on the application. It is preferable to apply as described above. In general, when a paint is applied with a film thickness exceeding 20 μm, it tends to curl greatly compared to the case where it is applied with a relatively thin film thickness, but the paint of the present invention is excellent in curling resistance. Since it has characteristics, curling hardly occurs even when it is applied with a relatively high film thickness exceeding 20 μm, and it can be suitably used. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, and screen printing.

  Among the plastic films, the polymethyl methacrylate film is generally relatively thick and strong, with a thickness of about 100 to 2,000 μm, so it is suitable for applications that require a particularly high surface hardness, such as applications for front plates of liquid crystal displays. It is the film used for. When the polymethyl methacrylate film is used as a base material, the coating amount when applying the coating material of the present invention is in the range of 1 to 100 μm, preferably 7 to 80 μm after drying, in accordance with the application. It is preferable to apply so that it becomes. In general, when a coating is applied on a relatively thick film such as a polymethyl methacrylate film to a film thickness exceeding 30 μm, it becomes a laminated film having a high surface hardness, but the transparency tends to decrease. However, since the coating material of the present invention has very high transparency as compared with the conventional coating material, a laminated film having both high surface hardness and transparency can be obtained. Examples of the coating method at that time include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing, and screen printing.

  Examples of the active energy rays irradiated when the coating material of the present invention is cured to form a coating film include ultraviolet rays and electron beams. In the case of curing with ultraviolet rays, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, and an LED lamp as a light source is used, and the amount of light, the arrangement of the light sources, and the like are adjusted as necessary. When using a high-pressure mercury lamp, it is preferable to cure at a conveyance speed of 5 to 50 m / min for one lamp having a light quantity that is usually in the range of 80 to 160 W / cm. On the other hand, in the case of curing with an electron beam, it is preferably cured with an electron beam accelerator having an accelerating voltage that is usually in the range of 10 to 300 kV at a conveyance speed of 5 to 50 m / min.

  Moreover, the base material to which the paint of the present invention is applied can be suitably used not only as a plastic film but also as a surface coating agent for various plastic molded products, for example, cellular phones, electric appliances, automobile bumpers and the like. . In this case, examples of the method for forming the coating film include a coating method, a transfer method, and a sheet bonding method.

  The coating method is a method in which the paint is spray-coated or coated as a top coat on a molded product using a printing device such as a curtain coater, roll coater, gravure coater, etc., and then cured by irradiation with active energy rays. is there.

  In the transfer method, a transfer material obtained by applying the above-described coating material of the present invention on a substrate sheet having releasability is adhered to the surface of the molded product, and then the substrate sheet is peeled off to top coat the surface of the molded product. , And then curing by irradiation with active energy rays, or by bonding the transfer material to the surface of the molded article, curing by irradiation with active energy rays, and then peeling the substrate sheet A method of transferring the top coat to the surface is mentioned.

  On the other hand, in the sheet bonding method, a protective sheet having a coating film made of the paint of the present invention on a base sheet, or a protective sheet having a coating film made of the paint and a decorative layer on a base sheet is plastic molded. In this method, a protective layer is formed on the surface of the molded product by bonding to the product.

  Among these, the coating material of the present invention can be preferably used for the transfer method and the sheet adhesion method.

  In the transfer method, first, a transfer material is prepared. The transfer material can be produced by, for example, applying the paint alone or mixed with a polyisocyanate compound on a base sheet and heating to semi-cure (B-stage) the coating film. .

  In order to produce a transfer material, first, the above-described paint of the present invention is applied onto a base material sheet. Examples of the method for applying the paint include a gravure coating method, a roll coating method, a spray coating method, a lip coating method, a coating method such as a comma coating method, and a printing method such as a gravure printing method and a screen printing method. The coating thickness is preferably such that the thickness of the coated film after curing is 1 to 50 μm, since the wear resistance and chemical resistance are good, and 3 to 40 μm. It is more preferable to paint on.

  After coating the coating material on the substrate sheet by the previous method, the coating film is heat-dried and the coating film is semi-cured (B-tage). The heating is usually 55 to 160 ° C, preferably 100 to 140 ° C. The heating time is usually 30 seconds to 30 minutes, preferably 1 to 10 minutes, more preferably 1 to 5 minutes.

  For example, the surface protective layer of the molded product using the transfer material may be formed by, for example, bonding the B-staged resin layer of the transfer material and the molded product, and then irradiating active energy rays to cure the resin layer. To do. Specifically, for example, the B-staged resin layer of the transfer material is adhered to the surface of the molded product, and then the B-staged resin layer of the transfer material is removed by peeling the base sheet of the transfer material. After transferring onto the surface of the molded product, energy rays are cured by irradiation with active energy rays to cure the resin layer by cross-linking (transfer method), or the transfer material is sandwiched in a mold and the resin is placed in the cavity. At the same time as injection filling to obtain a resin molded product, a transfer material is adhered to the surface, the substrate sheet is peeled off and transferred onto the molded product, and then the energy beam is cured by irradiation with active energy rays to crosslink and cure the resin layer. And the like (molding simultaneous transfer method).

  Next, the sheet bonding method is specifically a resin layer formed by bonding a base sheet and a molded product of a protective layer forming sheet prepared in advance and then thermosetting by heating to form a B-stage. A method of performing cross-linking curing (post-adhesion method), and the protective layer forming sheet is sandwiched in a molding die, and a resin is injected and filled in the cavity to obtain a resin molded product, and at the same time, the surface and the protective layer are formed. For example, there may be mentioned a method in which a resin sheet is bonded and then thermally cured by heating to crosslink and cure the resin layer (molding simultaneous bonding method).

  Next, the coating film of the present invention is a coating film formed by applying and curing the coating material of the present invention on the above-described plastic film, or coating and curing the coating material of the present invention as a surface protective agent for plastic molded products. The laminated film of the present invention is a film in which a coating film is formed on a plastic film.

  Among the various uses of the film, as described above, a film obtained by applying the paint of the present invention on a plastic film and irradiating an active energy ray is used as a protective film for a polarizing plate used for a liquid crystal display, a touch panel display or the like. It is preferable to use as the coating film hardness. Specifically, when the paint of the present invention is applied to a protective film of a polarizing plate used for a liquid crystal display, a touch panel display, etc., and the film is formed by irradiating and curing active energy rays, the cured coating film has a high hardness. It becomes a protective film that combines high transparency. In the use of a protective film for a polarizing plate, an adhesive layer may be formed on the opposite surface of the coating layer to which the paint of the present invention is applied.

  Hereinafter, the present invention will be described more specifically with reference to specific production examples and examples, but the present invention is not limited to these examples. Unless otherwise indicated, all parts and percentages in the examples are based on mass.

  In the Example of this invention, a weight average molecular weight (Mw) is the value measured on condition of the following using a gel permeation chromatograph (GPC).

Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Tosoh Corporation guard column HXL-H
+ Tosoh Corporation TSKgel G5000HXL
+ Tosoh Corporation TSKgel G4000HXL
+ Tosoh Corporation TSKgel G3000HXL
+ Tosoh Corporation TSKgel G2000HXL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 1.0 ml / min Standard: Polystyrene sample: 0.4 mass% tetrahydrofuran solution filtered in terms of resin solids with a microfilter (100 μl)

[Pencil hardness test]
1. Preparation method of test piece The active energy ray-curable resin composition obtained in each Example and Comparative Example was applied on a film with a bar coater so as to have a predetermined film thickness after curing, and irradiated with active energy rays. And the laminated film which has a cured coating film by the heat processing was obtained.
2. Pencil Hardness Test Method The surface of the cured coating film obtained above was evaluated by a pencil scratch test with a load of 500 g according to JIS K 5400. The test was conducted five times, and the hardness one degree lower than the hardness at which scratches were made once or more was defined as the pencil hardness of the coating film.

[Abrasion resistance test]
1. Preparation method of cured coating film A coating film was prepared in the same manner as in the pencil hardness test.
2. Steel Wool Resistance Test Steel Wool (Japan Steel Wool Co., Ltd. “Bonster # 0000” 0.5 g is wrapped with a disc-shaped indenter with a diameter of 2.4 cm, and a 1 kg weight load is applied to the indenter to coat the film. The film surface was reciprocated 100 times, and the haze value of the coating film before and after the test was measured using “Haze Computer HZ-2” manufactured by Suga Test Instruments Co., Ltd. and evaluated by the difference δH. It is a cured coating film with excellent scratch resistance.

[Bendability test]
1. Preparation method of cured coating film A coating film was prepared on a polyester film (film thickness 75 μm) by the same method as in the pencil hardness test (film thickness after curing: 18 μm).
2. Bendability test Using a mandrel tester (TP Tester's “Bend Tester”), the laminated film is wrapped around a test bar, and a test is performed to visually check whether a cured coating layer of the film is cracked. The minimum diameter of the test bar that does not cause cracks was taken as the evaluation result. The smaller the minimum diameter, the better the bendability.

Synthesis Example 1: Production of branched acrylic acrylate resin (A-1) 254 parts by mass of methyl isobutyl ketone was charged into a high-pressure sealed reactor equipped with a stirrer, a cooling tube, a dropping funnel and a nitrogen introduction tube, and the system was stirred. The temperature was raised until the internal temperature reached 150 ° C., and then 229 parts by mass of glycidyl methacrylate, 153 parts by mass of methyl methacrylate and t-butylperoxy-2-ethylhexanoate (“Perbutyl O” manufactured by NOF Corporation) ) After dropping a mixed solution consisting of 23 parts by mass and 12 parts by mass of 1,1′-bis- (t-butylperoxy) cyclohexane (“Perhexa C” manufactured by NOF Corporation) from the dropping funnel over 3 hours, 150 Hold for 2 hours at ° C. Next, after the temperature was lowered to 90 ° C., 0.1 part by weight of methoquinone and 118 parts by weight of acrylic acid were added, 3 parts by weight of triphenylphosphine was added, the temperature was further raised to 110 ° C., and the acid value was 3 mgKOH / g It confirmed that it was the following and obtained the acrylic polymer (a-1). The property values of the acrylic polymer (a-1) were as follows.
Weight average molecular weight (Mw): 6,500,
Theoretical acryloyl group equivalent derived from acrylic acid in terms of solid content: 309 g / eq.
Next, 10 parts by mass of HDI and 0.1 part by mass of tin octylate were added and held at 80 ° C. for 5 hours, and it was confirmed that NCO% was 0.3 or less. Subsequently, it diluted with methyl isobutyl ketone and the methyl isobutyl ketone solution (nonvolatile content 50.0 mass%) of branched acrylic acrylate resin (A-1) was obtained. Each property value of this branched acrylic acrylate resin (A-1) was as follows.
Weight average molecular weight (Mw): 20,600,
Theoretical acryloyl group equivalent derived from acrylic acid in terms of solid content: 316 g / eq.

Synthesis Examples 2 to 4, Comparative Synthesis Examples 7 and 8
Synthesis Example 1 except that the amount of glycidyl methacrylate (GMA), methyl methacrylate (MMA), acrylic acid (AA) used, and the compound to be reacted with the obtained acrylic polymer are those shown in Table 1. In the same manner as in Example 1, branched acrylic acrylate resins (A-2) to (A-4) and a comparative acrylic polymer (A′-1) were obtained. The branched acrylic acrylate resin (A′-2) for comparison was stopped because the gelation occurred when 17.5 parts by mass of HDI and 0.1 part by mass of tin octylate were added and held at 80 ° C. for 1 hour. did.

Synthesis Example 5: Production of branched acrylic acrylate resin (A-5) 254 parts by mass of methyl isobutyl ketone was charged into a high-pressure sealed reactor equipped with a stirrer, a cooling tube, a dropping funnel and a nitrogen introducing tube, and the system was stirred. The temperature was raised until the internal temperature reached 150 ° C., and then 229 parts by mass of glycidyl methacrylate, 153 parts by mass of methyl methacrylate and t-butylperoxy-2-ethylhexanoate (“Perbutyl O” manufactured by NOF Corporation) ) After dropping a mixed solution consisting of 23 parts by mass and 12 parts by mass of 1,1′-bis- (t-butylperoxy) cyclohexane (“Perhexa C” manufactured by NOF Corporation) from the dropping funnel over 3 hours, 150 The precursor (2-5) was obtained by keeping at 2 ° C. for 2 hours. The property values of the precursor (2-5) were as follows.
Weight average molecular weight (Mw): 4,000
Next, after the temperature was lowered to 90 ° C., 0.1 part by weight of methoquinone, 111 parts by weight of acrylic acid and 10 parts by weight of adipic acid were added, 3 parts by weight of triphenylphosphine was added, and the temperature was further raised to 110 ° C. The acid value was confirmed to be 3 mgKOH / g or less, and branched acrylic acrylate (A-5) was obtained. The property values of the acrylic acrylate (A-5) were as follows.
Weight average molecular weight (Mw): 22,000,
Theoretical acryloyl group equivalent derived from acrylic acid in terms of solid content: 312 g / eq.

Synthesis Example 6 and Comparative Synthesis Example 9
Synthesis Example 5 except that the amount of glycidyl methacrylate (GMA) and methyl methacrylate (MMA) used and the acrylic acid (AA) and the compound to be reacted with the obtained precursor are the same as those shown in Table 1. In the same manner as in Example 5, branched acrylic acrylate resins (A-5) to (A-6) were obtained. Since the comparative branched acrylic acrylate resin (A′-3) was gelled when it was held at 110 ° C. for 1 hour, the reaction was stopped.

Footnotes in Table 1:
HDI: hexamethylene diisocyanate 24A-100: biuret of hexamethylene diisocyanate manufactured by Asahi Kasei Chemicals Co., Ltd. AdA: adipic acid SeA: sebacic acid

Example 1
Active energy ray-curable resin composition by adding 40 parts by mass of DPHA (Aronics M-404) and 4 parts by mass of Irgacure 184 to 120 parts by mass of the branched acrylic acrylate resin (A-1) obtained in Synthesis Example 1. Got.

This active energy ray-curable resin composition was coated on a PET film (75 μA 4300 manufactured by Toyobo Co., Ltd.) so as to have a dry film thickness of 18 μm, and cured at 500 mJ / cm ² with an irradiator equipped with a high-pressure mercury lamp. A laminated film was obtained.

Examples 2 to 9 and Comparative Example 1
In the same manner as in Example 1, an active energy ray-curable resin composition was prepared by blending each material with the blending amount (mass basis) shown in Table 2. In Example 8, the cured coating film was further subjected to a heat treatment at 150 ° C. for 30 minutes. In Example 9, inorganic fine particles (D) were blended, and the preparation method was dispersion by a wet ball mill. The results are shown in Table 2.

Each condition of dispersion by the wet ball mill is as follows.
Media: Zirconia beads having a median diameter of 100 μm Filling ratio of resin composition with respect to the inner volume of the mill: 70% by volume
Peripheral speed at the tip of the stirring blade: 11 m / sec
Flow rate of resin composition: 200 ml / min
Dispersion time: 60 minutes

The abbreviations in Table 2 are as follows.
Aronix M-404: Dipentaerythritol hexaacrylate / dipentaerythritol pentaacrylate manufactured by Toagosei Co., Ltd. Aerosil R7200: “Aerosil R7200” manufactured by Nippon Aerosil Co., Ltd. Silica fine particles having

As a result of intensive studies to solve the above problems, the present inventors have a hydroxyl group and a (meth) acryloyl group, an acid value of 4.4 mgKOH / g or less, and a weight average molecular weight (Mw) of 3. , An acrylic polymer (a1) in the range of 1,000 to 15,000 and a compound (b1) having two or more isocyanate groups in one molecule, and a weight average molecular weight (Mw) of 6,000 to 6,000. An active energy ray-curable resin composition containing a branched acrylic acrylate resin (A) in the range of 70,000 as an essential component exhibits a very high surface hardness after curing, and a plastic substrate The present invention has been completed by finding that it is rich in workability (flexibility) when applied and cured.

That is, the present invention provides an acrylic polymer having a hydroxyl group and a (meth) acryloyl group, an acid value of 4.4 mgKOH / g or less, and a weight average molecular weight (Mw) in the range of 3,000 to 15,000. A branched acrylic acrylate resin having a weight average molecular weight (Mw) in the range of 6,000 to 70,000 as a reaction raw material using the compound (a1) and a compound (b1) having two or more isocyanate groups in one molecule ( The present invention provides an active energy ray-curable resin composition containing A) as an essential component, a paint containing the same, a cured coating film, and a laminated film having the coating layer.

The active energy ray-curable resin composition of the present invention has a hydroxyl group and a (meth) acryloyl group, an acid value of 4.4 mgKOH / g or less, and a weight average molecular weight (Mw) of 3,000 to 15, 000-acrylic polymer (a1) and a compound (b1) having two or more isocyanate groups in one molecule are used as reaction raw materials, and the weight average molecular weight (Mw) is in the range of 6,000 to 70,000. The branched acrylic acrylate resin (A) is contained as an essential component.

Among the production methods of the branched acrylic acrylate resin (A) described above, from the viewpoint of easier synthesis , glycidyl ( meth) acrylate is used and copolymerized with (meth) acrylic acid ester to give a precursor ( 1), (meth) acrylic acid is reacted with the precursor (1) to obtain an acrylic polymer (a), and a branched acrylic acrylate resin obtained by reacting this with a biuret of hexamethylene isocyanate It is particularly preferred that

Synthesis Examples 2 to 4, Comparative Synthesis Example 5
Synthesis Example 1 except that the amount of glycidyl methacrylate (GMA), methyl methacrylate (MMA), acrylic acid (AA) used, and the compound to be reacted with the obtained acrylic polymer are those shown in Table 1. In the same manner as in Example 1, branched acrylic acrylate resins (A-2) to (A-4) and a comparative acrylic polymer (A′-1) were obtained .

Examples 2 to 7 and Comparative Example 1
In the same manner as in Example 1, an active energy ray-curable resin composition was prepared by blending each material with the blending amount (mass basis) shown in Table 2. In Example 6 , the cured coating film was further subjected to a heat treatment at 150 ° C. for 30 minutes. In Example 7 , inorganic fine particles (D) were blended, and the preparation method was dispersion by a wet ball mill. The results are shown in Table 2.

Claims (20)

A weight average molecular weight (Mw) formed by connecting a plurality of acrylic polymers (a) having a (meth) acryloyl group in the side chain via a functional group other than the (meth) acryloyl group is 6,000 to 70, An active energy ray-curable resin composition comprising a branched acrylic acrylate resin (A) in the range of 000 as an essential component. The active energy ray-curable resin composition according to claim 1, wherein the branched acrylic acrylate resin (A) has a (meth) acryloyl group equivalent in a range of 200 to 700 eq / g. The branched acrylic acrylate resin (A) has a hydroxyl group and a (meth) acryloyl group and a weight average molecular weight (Mw) in the range of 3,000 to 15,000, and in one molecule. The active energy ray-curable resin composition according to claim 1 or 2, which is obtained by reacting a compound (b1) having two or more isocyanate groups. The hydroxyl group in the linear acrylic polymer (a1) in which the branched acrylic acrylate resin (A) has the hydroxyl group and the (meth) acryloyl group and the weight average molecular weight (Mw) is in the range of 3,000 to 15,000. 4. The active energy ray-curable type according to claim 3, wherein the isocyanate group in the compound (b1) having an isocyanate group is reacted so as to be 0.002 to 0.25 mol with respect to 1 mol. Resin composition. The active energy ray-curable type according to claim 3 or 4, wherein the compound (b1) having two or more isocyanate groups in one molecule is hexamethylene diisocyanate, hexamethylene diisocyanate biuret, or hexamethylene diisocyanate nurate. Resin composition. The branched acrylic acrylate resin (A) comprises a glycidyl group-containing acrylic polymer (a2) having a weight average molecular weight (Mw) in the range of 2,000 to 14,000, and a (meth) acryloyl group in one molecule. The active energy ray-curable resin composition according to claim 1 or 2, which is obtained by reacting a compound (b2) having a carboxyl group with a compound (b3) having two or more carboxyl groups in one molecule. object. The glycidyl in the acrylic polymer (a2) in which the branched acrylic acrylate resin (A) has a glycidyl group, a hydroxyl group, and a (meth) acryloyl group and has a weight average molecular weight (Mw) in the range of 2,000 to 14,000. 1 mol of the group, the carboxyl group in the compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule, and the carboxyl group in the compound (b3) having two or more carboxyl groups in one molecule The active energy ray-curable resin composition according to claim 6, wherein the active energy ray-curable resin composition is reacted by being used so that the total number of moles is 0.9 to 1.2 mol. The active energy ray-curable resin composition according to claim 6 or 7, wherein the compound (b2) having a (meth) acryloyl group and a carboxyl group in one molecule is (meth) acrylic acid. The active energy ray-curable resin composition according to any one of claims 6 to 8, wherein the compound (b3) having two or more carboxyl groups in one molecule is adipic acid, sebacic acid, or dimer acid. Furthermore, the active energy ray hardening-type resin composition of any one of Claims 1-9 containing (meth) acrylate (C) other than the said branched acrylic acrylate resin (A). The active energy ray-curable resin composition according to claim 10, wherein the (meth) acrylate (C) is a polyfunctional (meth) acrylate having 3 or more (meth) acryloyl groups in one molecule. The active energy ray-curable resin composition according to claim 10, wherein the (meth) acrylate (C) has a hydroxyl group. 11. The (meth) acrylate (C) is dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, pentalysitol tetraacrylate, pentaerythritol triacrylate, or pentaerythritol diacrylate. The active energy ray-curable resin composition described. The active energy ray-curable resin composition according to any one of claims 1 to 13, further comprising inorganic fine particles (D). The active energy ray-curable resin composition according to claim 14, wherein the inorganic fine particles (D) are dry silica. A paint comprising the active energy ray-curable resin composition according to claim 1. A coating film obtained by curing the paint according to claim 16. The coating film according to claim 17, wherein the curing includes a heat treatment step of 60 ° C. or higher. A laminated film comprising the coating film according to claim 17 or 18 on one side or both sides of a plastic film. The laminated film according to claim 19, wherein the thickness of the coating film is in the range of 1 to 100 μm.