JP2013204026A - Active energy ray-curable resin composition, method for producing the same and molded article with cured film thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-curable resin composition, a method for producing the same, and a molded article with a cured film thereof exhibiting high scratch resistance when the cured film is formed, and capable of preventing silica fine particles from easily falling even when the cured film is rubbed.SOLUTION: An active energy ray-curable resin composition includes an inorgnic oxide-acrylic resin composite (α) prepared by binding an acrylic resin (A) containing an ethylenically unsaturated group in a side chain and fine inorganic oxide particles (B) containing colloidal silica as the principal component via a binding part represented by formula (1)-O-Si-R-NHCOO- (wherein Ris a 1-10C linear or branched alkylene group), and a photopolymerization initiator (C).

Description

  The present invention relates to an active energy ray-curable resin composition capable of improving the scratch resistance of a molded product by coating the surface of the molded product with a cured film, a method for producing the same, and a molding provided with the cured film. It is about goods.

  Conventionally, the surface of a molded product made of plastic or the like is covered with a cured film of a resin composition, and the cured product is protected by this cured film and its scratch resistance is improved. When the resin composition becomes a cured body, it not only gives excellent scratch resistance to the molded product, but also does not peel off or shift from the molded product, and the molded product is thin Therefore, it is required to have a property that no curling (warping) occurs.

In addition, when imparting scratch resistance to a molded product using such a resin, the active energy beam is not irradiated on another substrate sheet having releasability, instead of coating the resin on the surface of the molded product. There is a transfer method in which a transfer material with a protective layer made of a resin is formed, the transfer material is adhered to the surface of the molded product, the substrate sheet is peeled off, and the protective layer is transferred to the surface of the molded product A method of curing the protective layer by irradiating the protective layer on the surface of the molded product with active energy rays after the transfer has been studied. At this time, the protective layer is required to form a tack-free film at around room temperature (for example, 25 ° C. ± 5 ° C.) at least to the extent that it is not liquid after solvent drying and is not sticky to the touch. (Hereinafter, in the present invention, the ability to form a film that is not liquid and that is not tacky to the touch with a finger after solvent drying is sometimes referred to as “film-forming ability”).
As such a resin composition, for example, a resin composition described in Patent Document 1 has been proposed.

  That is, in Patent Document 1, acrylic acid or the like is reacted with a copolymer having an epoxy equivalent of 200 to 1000 g / eq and a weight average molecular weight of 5,000 to 100,000, and then silica fine particles or the like are mixed therewith. An active energy ray-curable resin composition is disclosed, and it is said that a film made of a cured body excellent in scratch resistance and heat resistance can be formed.

JP 2009-242647 A

  However, with an epoxy equivalent of 200 to 1000 g / eq in the copolymer, the amount of acrylic acid or the like that can be introduced thereafter decreases, and the scratch resistance of the finally obtained cured film deteriorates. Further, in this active energy ray-curable resin composition, the silica fine particles are merely blended and not bonded to the resin portion, so that when the cured film is rubbed, the silica fine particles are rubbed. The problem of falling off occurs.

  The present invention has been made in view of such circumstances, and has high scratch resistance when it becomes a cured film. Further, even when the cured film is rubbed, the silica fine particles do not fall off, and the occurrence of curling also occurs. An object of the present invention is to provide a suppressed active energy ray-curable resin composition, a method for producing the same, and a molded product having the cured film.

  That is, as a result of intensive studies to achieve the above object, the present inventors have found that in the active energy ray-curable resin composition, an acrylic resin (A) containing an ethylenically unsaturated group in the side chain and When an inorganic oxide-acrylic resin composite (α) formed by bonding inorganic oxide fine particles (B) containing colloidal silica as a main component via a bonding site represented by the following formula (1) is used, The inorganic oxide-acrylic resin composite (α) is bonded to the inorganic oxide fine particles (B) even in the vicinity of the center other than the end portion of the chain of the specific acrylic resin (A). Since the resin (A) has a structure that covers the whole of the inorganic oxide fine particles (B), it has a film-forming ability even before irradiation with active energy rays, and after irradiation with active energy rays. The cured film is The present inventors completed the present invention by finding that the shrinkage due to curing is reduced and the silica fine particles do not easily fall off even when the cured film is rubbed, and that they have excellent scratch resistance.

In the present invention, the acrylic resin (A) containing an ethylenically unsaturated group in the side chain and the inorganic oxide fine particles (B) mainly composed of colloidal silica are represented by the following formula (1). An active energy ray-curable resin composition containing an inorganic oxide-acrylic resin composite (α) formed through a binding site and a photopolymerization initiator (C) is a first gist.
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]

And it is a manufacturing method of the active energy ray-curable resin composition of the 1st summary, Comprising: [I] Monomer containing the monomer (a1) which has an epoxy group and one ethylenically unsaturated group An acrylic resin (A) is produced by adding a compound (a4) having a carboxyl group and a (meth) acryloyl group to a polymer (a3) having an epoxy group obtained by polymerizing the body component [i]. And [II] a step of reacting the isocyanate group of the compound (a5) having an isocyanate group and an alkoxysilyl group with the hydroxyl group produced during the addition reaction to produce a reaction product (A-a5); III] By reacting the alkoxysilyl group in the reaction product (A-a5) with the hydroxyl group in the inorganic oxide fine particles (B) mainly composed of colloidal silica, the acrylic resin (A) and the inorganic acid are reacted. Objects and particles (B), but inorganic oxides formed by bonding via a binding site represented by the formula (1) - a step of producing acrylic resin complex (alpha),
[IV] A method for producing an active energy ray-curable resin composition comprising a step of mixing a photopolymerization initiator (C) with the inorganic oxide-acrylic resin composite (α) To do.

  A method for producing an active energy ray-curable resin composition according to the first aspect, wherein the step [I], [V] a hydroxyl group, an isocyanate group, and an alkoxysilyl in the inorganic oxide fine particles (B) are provided. Reacting an alkoxysilyl group in the compound (a5) having a group to produce a reaction product (B-a5), [VI] an isocyanate group in the reaction product (B-a5) and an acrylic group Inorganic oxidation formed by reacting the hydroxyl group in the resin (A) with the acrylic resin (A) and the inorganic oxide fine particles (B) via the bonding site represented by the above formula (1). Activity comprising: a step of producing a product-acrylic resin composite (α); and a step of [VII] mixing a photopolymerization initiator (C) together with the inorganic oxide-acrylic resin composite (α). Production of energy ray curable resin composition How to the third aspect.

  Furthermore, a molded article provided with a cured film in which at least a part of the surface is coated with the cured film of the active energy ray-curable resin composition of the first aspect is a fourth aspect.

  Thus, the active energy ray-curable resin composition of the present invention comprises an acrylic resin (A) containing an ethylenically unsaturated group in the side chain, and inorganic oxide fine particles (B) mainly composed of colloidal silica. Contains an inorganic oxide-acrylic resin composite (α) formed by binding via the binding site represented by the above formula (1), and the inorganic oxide-acrylic resin composite (α) In addition to the end portion of the chain of the specific acrylic resin (A), a bond is formed with the inorganic oxide fine particles (B), particularly near the center, and the inorganic oxide is effectively oxidized by the specific acrylic resin (A). The structure is such that the object fine particles (B) are covered. For this reason, it comes to have a film-forming ability even in a state before irradiation with active energy rays.

  In addition, the active energy ray-curable resin composition of the present invention has a small amount of cure shrinkage of the cured film after irradiation with active energy rays, and has a high surface hardness. Even if the surface of the cured film is rubbed, the silica fine particles Since it does not fall off, the scratch resistance is greatly improved.

  Furthermore, when the weight average molecular weight of the acrylic resin (A) is 10,000 to 100,000, the viscosity becomes easy to apply, and the inorganic oxide fine particles (B) can be sufficiently covered. This is preferable in that aggregation of the fine particles (B) and gelation of the resulting resin composition can be prevented.

  Moreover, the transparency of the cured film is securable that the average particle diameter of the said inorganic oxide microparticles | fine-particles (B) is 10-100 nm.

  And when the compounding quantity of the said inorganic oxide microparticles | fine-particles (B) is 5-400 weight part with respect to 100 weight part of acrylic resin (A), the adhesiveness with respect to a molded article increases, and also the cured film of The scratch resistance can be further improved and the life of the cured film can be extended.

  Next, an embodiment for carrying out the present invention will be described. The description of the constituent requirements described below is an example (representative example) of the embodiment of the present invention, and is not limited to these contents.

  In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate.

In the active energy ray-curable resin composition of the present invention, the specific acrylic resin (A) and the inorganic oxide fine particles (B) containing colloidal silica as a main component are bonded to the bonding site represented by the following formula (1). It contains an inorganic oxide-acrylic resin composite (α) and a photopolymerization initiator (C) that are bonded via a photocatalyst. Below, these components (A)-(C) are explained in full detail.
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]

<< Specific acrylic resin (A) >>
The specific acrylic resin (A) used in the present invention contains an ethylenically unsaturated group in the side chain. For example, an epoxy group obtained by polymerizing the following monomer component [i]: The compound (a4) having a carboxyl group and a (meth) acryloyl group can be added to the polymer (a3) having
The addition of the specific compound (a4) to the specific polymer (a3) is to react the epoxy group of the polymer (a3) with the carboxyl group of the compound (a4). Thus, the (meth) acrylolyl group of the compound (a4) is used as the ethylenically unsaturated group of the acrylic resin (A).

  The epoxy equivalent of the polymer (a3) having an epoxy group obtained by polymerizing the monomer component [i] is preferably 200 or less, particularly preferably 190 or less, and further preferably 180 or less. When the epoxy equivalent is too high, the (meth) acryloyl group that can be introduced is reduced when the compound (a4) having a carboxyl group and a (meth) acryloyl group is added to the specific polymer (a3). As a result, there is a possibility that improvement in scratch resistance in a cured film obtained by photocuring the obtained active energy ray-curable resin composition may not be observed. The epoxy equivalent can be measured according to JIS K-7236. Moreover, it is preferable that the weight average molecular weights of the said polymer (a3) which has an epoxy group are 5,000-100,000, Most preferably, it is 6,000-90,000.

[Monomer component [i]]
The monomer component [i] for producing the polymer (a3) having an epoxy group includes the following monomer (a1) having an epoxy group and one ethylenically unsaturated group, and one And other monomer (a2) having an ethylenically unsaturated group.
(Monomer (a1) having an epoxy group and one ethylenically unsaturated group)
The monomer (a1) having the epoxy group and one ethylenically unsaturated group may be a (meth) acrylic acid ester having an epoxy group as a part of the ester group. Those having an alicyclic epoxy structure are preferred because the reaction at the time of photocuring the active energy ray-curable resin composition is fast. Examples of the (meth) acrylic acid ester having such an epoxy group as a part of the ester group include glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate. Acryester G (glycidyl methacrylate) manufactured by Mitsubishi Rayon Co., Ltd., and Cyclomer M100 (3,4-epoxycyclohexylmethyl methacrylate) manufactured by Daicel Chemical Industries, Ltd. These may be used alone or in combination of two or more.

  Although content of the said monomer (a1) is set so that the preferable range of the above-mentioned epoxy equivalent may be satisfied, Specifically, Preferably it is 70-100 with respect to the whole monomer component [i]. % By weight, particularly preferably 75 to 100% by weight. If the content of the monomer (a1) is too small, it can be introduced when the compound (a4) having a carboxyl group and a (meth) acryloyl group is added to the above-mentioned specific polymer (a3) ( As a result, the number of (meth) acryloyl groups decreases, and as a result, the scratch resistance of a cured film obtained by photocuring the obtained active energy ray-curable resin composition tends to be lowered.

(Other monomer having one ethylenically unsaturated group (a2))
As said monomer component [i], you may contain the other monomer (a2) which has the said monomer (a1), and one ethylenically unsaturated group, Such other single quantity Examples of the body (a2) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, and n-propyl (meth). ) Acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, Stearyl (meth) acrylate, iso-stearyl (meth) acrylate, etc. Alkyl acrylate esters; cyclohexyl (meth) acrylate, isobornyl (meth) alicyclic (meth) acrylic acid esters such as acrylates, styrene and the like. In the case of the above (meth) acrylic acid alkyl ester, the alkyl group preferably has 1 to 20 carbon atoms, particularly 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. These may be used alone or in combination of two or more. Among these, from the point that the obtained active energy ray-curable resin composition has a high film-forming ability even before active energy ray irradiation, a monomer having a high glass transition point of a homopolymer, for example, methyl ( It is preferable to use meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like.

  The content of the other monomer (a2) is preferably 0 to 30% by weight, particularly preferably 0 to 25% by weight, based on the entire monomer component [i]. When the content of the other monomer (a2) is too large, it is introduced when the compound (a4) having a carboxyl group and a (meth) acryloyl group is added to the above-mentioned specific polymer (a3). (Meth) acryloyl groups that can be reduced are reduced, and as a result, the scratch resistance of a cured film obtained by photocuring the obtained active energy ray-curable resin composition tends to be lowered.

(Compound (a4) having a carboxyl group and a (meth) acryloyl group)
Examples of the specific compound (a4) include (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyhexahydrophthal Examples thereof include a reaction product of an acid, a carboxylic acid or a derivative thereof and a hydroxyl group-containing (meth) acrylate.
Examples of the carboxylic acid and derivatives thereof include succinic acid, succinic anhydride, phthalic acid, and phthalic anhydride. Examples of the hydroxyl group-containing (meth) acrylate include pentaerythritol tri (meth) acrylate, Examples thereof include pentaerythritol penta (meth) acrylate.

  Among these, (meth) acrylic acid, pentaerythritol tri (meth) acrylate and succinic anhydride reaction product, pentaerythritol tri (meth) acrylate and phthalic anhydride It is preferable to use a reaction product, a reaction product of dipentaerythritol penta (meth) acrylate and phthalic anhydride.

(Method for producing specific acrylic resin (A))
1. First, the monomer component [i] is polymerized to produce a polymer (a3) having an epoxy group. Examples of the method for polymerizing the monomer component [i] include solution radical polymerization, suspension polymerization, bulk polymerization, and emulsion polymerization. Among these, polymerization by solution radical polymerization is preferable from the viewpoint of easy control of the reaction. This solution radical polymerization is performed, for example, by mixing or dropping the monomer component [i] and the polymerization initiator in a solvent and heating and stirring. The heating conditions are appropriately set depending on the solvent used, the type of monomer component [i], and the type of polymerization initiator, but are usually in the range of 50 to 150 ° C., and the reaction time is in the range of 2 to 20 hours. It is.

A radical polymerization agent can be used as the polymerization initiator. Examples of such radical polymerization agents include azo polymerization initiators such as asobisisobutyronitrile and azobisdimethylvaleronitrile, benzoyl peroxide, lauryl peroxide, di-t-butyl peroxide, cumene hydroxy peroxide. And other peroxide-based polymerization initiators.
Moreover, as said solvent, what can melt | dissolve the specific acrylic resin (A) obtained is preferable. Examples of such solvents include ketones such as 2-propanone, 4-methyl-2-pentanone, and cyclohexaneone, ethyl acetate, butyl acetate, 1-methoxy-2-propyl acetate, 1,2-diacetoxypropane. And ethers such as tetrahydrofuran and 1,4-dioxane. These may be used alone or in combination of two or more.
However, it is not preferable to use a solvent having a hydroxyl group or an amine. In the subsequent step, when the compound (a5) having an isocyanate group and an alkoxysilyl group is reacted with the hydroxyl group of the specific acrylic resin (A) to produce the reaction product (A-a5), the above-mentioned specific This is because the compound (a5) reacts with a hydroxyl group or an amine in the solvent.

2. Next, the specific acrylic resin (A) is manufactured by adding the compound (a4) which has a carboxyl group and a (meth) acryloyl group to the polymer (a3) which has the epoxy group manufactured above. . That is, the specific compound (a4) is mixed or dropped into the solvent containing the polymer (a3) having an epoxy group produced as described above, and these are heated and stirred.

  At this time, the ratio of the number of moles of the epoxy group in the specific polymer (a3) to the number of moles of the specific compound (a4) is preferably (a3) / (a4) = 1 to 10, ) / (A4) = 1 to 3 is more preferable. If the ratio of (a3) to (a4) [(a3) / (a4)] is too small, the unreacted specific compound (a4) remains in the active energy ray-curable resin composition obtained as the final product. This may cause waste and leave unreacted acid in the active energy ray-curable resin composition, which may cause corrosion due to acid in the molded product in contact with the active energy ray-curable resin composition. There is. On the other hand, if the ratio of (a3) to (a4) ((a3) / (a4)) is too large, there is a tendency that the scratch resistance of the cured film of the active energy ray-curable resin composition cannot be improved.

  And reaction at the time of adding a specific compound (a4) to the said specific polymer (a3) is normally performed at the temperature of 50-120 degreeC for 3 to 50 hours. The progress of this reaction can be confirmed by measuring the epoxy equivalent or acid value in the system. Although the reaction may be terminated at any stage, it is preferable to react 90 mol% or more of the blended specific compound (a4) from the viewpoint that no unreacted acid remains. In addition, the said acid value can be measured by the method based on JISK5601-2-1.

  In addition, a catalyst can be used to promote the reaction when the specific compound (a4) is added to the specific polymer (a3). Examples of such a catalyst include triethylamine, tributylamine, triethylenediamine, N, N-dimethylbenzylamine, benzyltrimethylammonium chloride, tetramethylammonium bromide, tributylphosphine, and triphenylphosphine. And the usage-amount of this catalyst is preferably 0.01-5 weight% with respect to the total weight of a specific polymer (a3) and a specific compound (a4), 0.05-2 weight% It is more preferable that

  Furthermore, the (meth) acryloyl group contained in the specific compound (a4) is prevented from being polymerized during the reaction when the specific compound (a4) is added to the specific polymer (a3). Therefore, a polymerization inhibitor can be used. Examples of such a polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, catechol, pt-butylcatechol, phenothiazine and the like. The amount of the polymerization inhibitor used is preferably 0.01 to 1% by weight with respect to the total weight of the specific polymer (a3) and the specific compound (a4), and 0.05 to 0 More preferably, it is 5% by weight.

  The specific acrylic resin (A) thus obtained preferably has a weight average molecular weight of 10,000 to 100,000, more preferably 20,000 to 50,000. If the weight average molecular weight is too large, the viscosity of the active energy ray-curable resin composition tends to be too high and it becomes difficult to apply a uniform film thickness. Resin composition obtained by reducing the ability to form a cured film obtained by curing a linear curable resin composition or reducing the effect of covering the inorganic oxide fine particles (B), and aggregation of the inorganic oxide fine particles (B) The gelation tends to occur easily.

  The weight average molecular weight of the specific acrylic resin (A) can be controlled by the amount of the polymerization initiator used, the polymerization temperature condition, and the like. If necessary, a chain transfer agent can be added for finer control. it can. As the polymerization initiator, the above-mentioned radical polymerization initiator can be used. Examples of the chain transfer agent include mercaptans such as octyl mercaptan and lauryl mercaptan.

In addition, the said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, and can be measured by using a gel permeation chromatography. Specifically, high performance liquid chromatography (main body “waters 2695”, detector “waters 2414”, column “shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100˜ 2 × 10 ⁷ , theoretical plate number: 10,000 plate / line, filler material: styrene-divinylbenzene copolymer, filler particle diameter: 10 μm in series 3) ”).

<< Inorganic oxide fine particles based on colloidal silica (B) >>
The inorganic oxide fine particles (B) may be those containing colloidal silica as a main component, and may be obtained by a method such as neutralizing with water using water glass as a raw material or hydrolyzing an alkyl silicate with an alkali. Can do. Moreover, what is sold as a commercial item can also be used. In addition, "having colloidal silica as a main component" usually means a material containing 50% by weight or more of colloidal silica, and is intended to include those composed only of colloidal silica.

  Examples of the shape of the inorganic oxide fine particles (B) include a spherical shape, a hollow shape, a porous shape, a rod shape, a fiber shape, a plate shape, and an indefinite shape. Among them, it is more preferable to use a spherical shape. In addition, the spherical shape as used in the field of this invention does not mean only an exact | strict sphere but the meaning containing what is substantially spherical.

  In the present invention, in the form of an organosilica sol dispersed in an organic solvent, it is easy to mix with the specific acrylic resin (A), and it is easy to obtain a uniform active energy ray-curable resin composition. It is preferable to use colloidal silica. As the organic solvent, for example, 2-propanol, 1-methoxy-2-propanol, 2-propanone, 4-methyl-2-pentanone and the like are preferably used.

  The average particle size of the inorganic oxide fine particles (B) is preferably 10 to 100 nm, particularly preferably 10 when considering transparency of the cured film of the active energy ray-curable resin composition, for example. ~ 50 nm. If the average particle size is too large, the transparency tends to decrease. Conversely, if the average particle size is too small, the inorganic oxide fine particles (B) tend to aggregate or the mechanical properties of the resulting composition tend to decrease. Is seen. In addition, the said average particle diameter is computed and calculated from the average specific surface area of the particle | grains calculated | required by BET method based on JISR1626, and the true specific gravity of particle | grains.

  Specifically as said inorganic oxide microparticles | fine-particles (B), IPA-ST (2-propanol dispersion | distribution, the average particle diameter of 10-15 nm) by Nissan Chemical Industries, PGM-ST (1-methoxy-2-propanol) Dispersion, average particle diameter of 10 to 15 nm), MEK-ST (2-propanone dispersion, average particle diameter of 10 to 15 nm), and the like.

  The blending amount of the inorganic oxide fine particles (B) is preferably 5 to 400 parts by weight, more preferably 25 to 150 parts by weight with respect to 100 parts by weight of the specific acrylic resin (A). More preferably, it is 30 to 100 parts by weight. When there are too many compounding quantities of inorganic oxide microparticles | fine-particles (B), the film formation capability before active energy ray irradiation of the obtained active energy ray-curable resin composition will fall, Therefore, an active energy ray-curable resin composition When the transfer material is used to coat the surface of the molded product by transferring the resin composition to the surface of the molded product using the transfer material, the resin composition is applied to the surface of the molded product. There is a tendency for adhesion to be insufficient. Conversely, if the amount of the inorganic oxide fine particles (B) is too small, there is a tendency that a sufficient effect of improving the scratch resistance of the cured film cannot be obtained.

<< Inorganic oxide-acrylic resin composite (α) >>
In the inorganic oxide-acrylic resin composite (α), the specific acrylic resin (A) and the inorganic oxide fine particles (B) are bonded through a bonding site represented by the following formula (1). By containing this inorganic oxide-acrylic resin composite (α), the pot life of the active energy ray-curable resin composition of the present invention becomes excellent, and further, this is cured. It is possible to improve the scratch resistance of the cured film.
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]

In the above formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms, and the alkylene group preferably has 1 to 4 carbon atoms, specifically, a methylene group, an ethylene group, An n-propylene group and an n-butylene group are preferred.

  In order to bond the specific acrylic resin (A) and the inorganic oxide fine particles (B) through the bonding site represented by the formula (1), both an isocyanate group and an alkoxysilyl group are bonded in one molecule. It can carry out by the method using the compound (a5) which has. This specific compound (a5) causes the inorganic oxide fine particles (B) to coexist when the isocyanate group reacts with the hydroxyl group of the specific acrylic resin (A) to hydrolyze the alkoxysilyl group. As a result, the inorganic oxide fine particles (B) are also bonded.

(Compound (a5) having an isocyanate group and an alkoxysilyl group)
Examples of the specific compound (a5) include 3-isocyanatopropyltriethoxysilane, and specific examples include KBE-9007 (3-isocyanatepropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

And as a method of manufacturing the said inorganic oxide-acrylic-type resin composite ((alpha)), as shown below, two methods from which the mixing order of a mixing | blending component differs are mention | raise | lifted, for example.
That is, [1]: [I] having an epoxy group obtained by polymerizing the monomer component [i] containing the monomer (a1) having an epoxy group and one ethylenically unsaturated group A step of producing an acrylic resin (A) by adding a compound (a4) having a carboxyl group and a (meth) acryloyl group to the polymer (a3), and [II] a hydroxyl group produced during the addition reaction, Reacting an isocyanate group of the compound (a5) having an isocyanate group and an alkoxysilyl group to produce a reaction product (A-a5); [III] an alkoxysilyl group in the reaction product (A-a5) And the hydroxyl group in the inorganic oxide fine particles (B) containing colloidal silica as a main component, the acrylic resin (A) and the inorganic oxide fine particles (B) are represented by the following formula (1). Binding site A step of producing an inorganic oxide-acrylic resin composite (α) formed by bonding, and [IV] a photopolymerization initiator (C) together with the inorganic oxide-acrylic resin composite (α). The manufacturing method provided with the process to mix.

  Or [2]: [I] having an epoxy group obtained by polymerizing the monomer component [i] containing the monomer (a1) having an epoxy group and one ethylenically unsaturated group A step of producing an acrylic resin (A) by adding a compound (a4) having a carboxyl group and a (meth) acryloyl group to the polymer (a3); [V] In the inorganic oxide fine particles (B) A step of producing a reaction product (B-a5) by reacting an alkoxysilyl group in the compound (a5) having a hydroxyl group, an isocyanate group and an alkoxysilyl group, and [VI] this reaction product (B-a5) ) And the hydroxyl group in the acrylic resin (A) are reacted with each other so that the acrylic resin (A) and the inorganic oxide fine particles (B) have a bonding site represented by the following formula (1). Inorganic oxidation formed through bonding Manufacturing a product-acrylic resin composite (α) and [VII] a step of mixing a photopolymerization initiator (C) together with the inorganic oxide-acrylic resin composite (α). There are two methods. These methods are described in detail below.

[1] Method for producing inorganic oxide-acrylic resin composite (α) (Production of reaction product (A-a5))
Isocyanate of the compound (a5) having an isocyanate group and an alkoxysilyl group on the hydroxyl group produced when the specific compound (a4) is added to the specific polymer (a3) in the specific acrylic resin (A) The reaction product (A-a5) is produced by reacting the groups. That is, the specific compound (a5) is mixed or dropped into the solution for producing the specific acrylic resin (A), and if necessary, heated and stirred.

  At this time, it is preferable that the compounding quantity of a specific compound (a5) is 0.1-20 mol% of the amount of hydroxyl groups produced at the time of the said specific acrylic resin (A) manufacture, and is 1-5 mol%. It is more preferable. When the compounding amount of the specific compound (a5) is too small, a compound having no binding site is generated between the specific acrylic resin (A) and the inorganic oxide fine particles (B), and the resulting active energy ray curability is obtained. There is a tendency that the scratch resistance of the cured film of the resin composition cannot be improved. On the contrary, if the amount is too large, the crosslinking between the specific acrylic resin (A) and the inorganic oxide fine particles (B) is activated energy rays. This is the same as that performed sufficiently before irradiation, and it tends to be difficult to handle the active energy ray-curable resin composition.

  In addition, the amount of hydroxyl groups generated during the production of the specific acrylic resin (A) is determined by the amount of the specific compound (a4) added to the specific polymer (a3) and the epoxy equivalent or acid value in the system. It can be estimated from the degree of progress of the reaction that can be confirmed by measurement.

  The reaction for producing the reaction product (A-a5) is usually performed at a temperature of room temperature to 90 ° C. for 1 to 50 hours. During this reaction, the reaction can be accelerated using a catalyst. Examples of such a catalyst include organic metal compounds such as dibutyltin dilaurate, trimethyltin hydroxide, and tetra-n-butyltin, zinc octoate, tin octoate, cobalt naphthenate, stannous chloride, and second chloride. Examples thereof include metal salts such as tin, amine catalysts such as triethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene. Of these, dibutyltin dilaurate is preferably used because it is easily available.

(Production of inorganic oxide-acrylic resin composite (α))
Next, the reaction product (A-a5) produced above and the inorganic oxide fine particles (B) containing colloidal silica as a main component are added with water to cause a hydrolysis condensation reaction, whereby the following formula (1) is satisfied. An inorganic oxide-acrylic resin composite (α) formed by bonding through the bonding sites shown can be produced.
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]

  At this time, the bond between the specific acrylic resin (A) and the inorganic oxide fine particles (B) is performed using an alkoxysilyl group derived from the specific compound (a5). It is obtained by reacting a specific compound (a5) with a hydroxyl group produced when a specific acrylic resin (A) is produced. And since a hydroxyl group exists uniformly in the molecular chain of the said specific acrylic resin (A), it is estimated that an alkoxy silyl group arises uniformly in the molecular chain of a reaction product (A-a5). . Therefore, since the reaction product (A-a5) has a binding site evenly in the entire molecular chain, the entire molecular chain is used to bind so as to cover the inorganic oxide fine particles (B). It is guessed. That is, when the inorganic oxide fine particles (B) are bonded to the alkoxysilyl group present in the central part of the molecular chain of the reaction product (A-a5), the reaction product (A It is considered that the molecular chain of -a5) covers and binds the inorganic oxide fine particles (B). For this reason, it is guessed that the whole molecular chain of a specific acrylic resin (A) can be used more effectively than the case where an alkoxysilyl group exists only in the terminal part of the molecular chain of a specific acrylic resin (A). Is done.

  In the reaction, the inorganic oxide fine particles (B) may be added to the solution containing the reaction product (A-a5) produced above, or the reaction product (A- A solution containing a5) may be added, but in any case the reaction is carried out by adding water to these mixtures. That is, the alkoxysilyl group derived from the compound (a5) having an isocyanate group and an alkoxysilyl group is hydrolyzed with water to produce a silanol group, which is a hydroxyl group on the surface of the inorganic oxide fine particles (B) (in the case of organosilica sol, silanol). And a specific acrylic resin (A) and inorganic oxide fine particles (B) are bonded via the bonding site represented by the above formula (1). Become. The amount of water to be added may be at least the amount that all of the alkoxysilyl groups derived from the specific compound (a5) can be hydrolyzed, and is 100 to 100 mols per mol of the alkoxysilyl groups derived from (a5). It is preferably 300 mol%, more preferably 100 to 200 mol%. The above reaction is usually performed at a temperature of room temperature to 100 ° C. for 1 to 100 hours.

  In order to accelerate the hydrolysis reaction, a catalyst can be added to the reaction system. Examples of such a catalyst include acetylacetone aluminum, aluminum diisopropoxide ethyl acetate, aluminum dibutoxide ethyl acetate, borate butoxide, acetic acid, propionic acid, hydrochloric acid, dibutyltin dilaurate, and trimethyltin hydroxide. The blending amount of the catalyst is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of the compound (a5) having an isocyanate group and an alkoxysilyl group and the inorganic oxide fine particles (B). More preferably, it is 0.5-5 weight part.

[2] Method for Producing Inorganic Oxide-Acrylic Resin Composite (α) The difference from the production method of [1] is that the specific acrylic resin (A) has an isocyanate group and an alkoxysilyl group (a5 The reaction product (A-a5) is not produced, but instead, the hydroxyl group in the inorganic oxide fine particles (B) mainly composed of colloidal silica and the alkoxy in the specific compound (a5) The reaction product (B-a5) is produced by reacting with a silyl group.

(Production of reaction product (B-a5))
The reaction product (B-a5) hydrolyzes the alkoxysilyl group derived from the specific compound (a5) with water to form a silanol group, and the hydroxyl group (B) on the surface of the inorganic oxide fine particles (B) In the case of an organosilica sol, it can be produced by a condensation reaction of a silanol group). The obtained reaction product (B-a5) is preferably used immediately for the reaction with the specific acrylic resin (A) from the viewpoint of preventing the isocyanate group from reacting with the blended water.

  It is preferable that the compounding quantity of the specific compound (a5) in the said reaction is 0.1-20 mol% of the amount of hydroxyl groups contained in the specific acrylic resin (A) made to react later, 1-5 More preferably, it is mol%. When the compounding amount of the specific compound (a5) is too small, the bonding site between the specific acrylic resin (A) and the inorganic oxide fine particles (B) depends on the molecular weight of the specific acrylic resin (A). In the case where the obtained active energy ray-curable resin composition is cured, there is a tendency that the scratch resistance of the cured film cannot be improved. Crosslinking between the resin (A) and the inorganic oxide fine particles (B) is the same as that sufficiently performed before irradiation with active energy rays, and the handling of the active energy ray-curable resin composition tends to be difficult.

  Further, unlike the production method of [1], a dispersion medium for the inorganic oxide fine particles having a hydroxyl group is not preferable. This is because when reacting with the specific acrylic resin (A), the isocyanate group of the reaction product (B-a5) is not only the hydroxyl group of the specific acrylic resin (A) but also the hydroxyl group of the dispersion medium. This is to react.

(Production of inorganic oxide-acrylic resin composite (α))
The inorganic oxide-acrylic resin composite (α) can be obtained by reacting the specific acrylic resin (A) with the reaction product (B-a5). That is, the specific acrylic resin (A) has a hydroxyl group generated when the specific compound (a4) is added to the specific polymer (a3). On the other hand, in the reaction product (B-a5), an isocyanate group is introduced by the hydrolysis condensation reaction described above. Therefore, the inorganic oxide-acrylic resin composite (α) can be produced by reacting the hydroxyl group of the specific acrylic resin (A) with the isocyanate group of the reaction product (B-a5).

  In the above reaction, the reaction product (B-a5) may be added to the solution containing the specific acrylic resin (A), or the specific acrylic resin may be added to the solution containing the reaction product (B-a5). (A) may be added. The above reaction is usually performed at a temperature of room temperature to 90 ° C for 1 to 50 hours.

  Moreover, in order to accelerate | stimulate the said reaction, a catalyst can be mix | blended with the said reaction system. Examples of such a catalyst include organic metal compounds such as dibutyltin dilaurate, trimethyltin hydroxide, and tetra-n-butyltin, zinc octoate, tin octoate, cobalt naphthenate, stannous chloride, Examples include amine catalysts such as metal salts such as 2 tin, triethylamine, 1,4-diazabicyclo [2,2,2] octane, and 1,8-diazabicyclo [5,4,0] undecene. Is easy to use, but dibutyltin dilaurate is preferably used.

<< Photopolymerization initiator (C) >>
The photopolymerization initiator (C) generates radicals and the like when irradiated with active energy rays. When ultraviolet rays are used as active energy rays, a normal photopolymerization initiator may be used. it can. Examples of such a photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diethoxyacetophenone, benzyldimethyl ketal, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl. Phenylketone, benzophenone, 2,4,6-trimethylbenzoindiphenylphosphine oxide, 2-methyl [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) -butan-1-one and the like. These may be used alone or in combination of two or more.

  Content of the said photoinitiator (C) is 0.1-10 weight part with respect to a total of 100 weight part of an inorganic oxide-acrylic-resin composite ((alpha)) and the below-mentioned polyfunctional acrylate (D). It is preferable that it is 1-5 weight part. If the content of the photopolymerization initiator (C) is too small, the active energy ray-curable resin composition is not sufficiently cured by irradiation with active energy rays, and the active energy ray-curable resin composition is cured. There is a tendency that the improvement of the scratch resistance of the film cannot be expected. On the other hand, if it is too much, unreacted materials that could not contribute to the curing reaction will later work as a plasticizer or cure the active energy ray curable resin composition The film tends to be deteriorated by receiving active energy rays.

  The active energy ray-curable resin composition of the present invention comprises the inorganic oxide-acrylic resin composite (α), the photopolymerization initiator (C), and, if necessary, a polyfunctional acrylate (D), a solvent ( E) and additives (F) can be contained. Below, these components (D)-(F) are explained in full detail.

<< Multifunctional acrylate (D) >>
Examples of the polyfunctional acrylate (D) include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa. (Meth) acrylate, tris ((meth) acryloxyethyl) isocyanurate and the like can be mentioned. These may be used alone or in combination of two or more.

  The content of the polyfunctional acrylate (D) is preferably 30 parts by weight or less, particularly preferably 20 parts by weight or less with respect to 100 parts by weight of the inorganic oxide-acrylic resin composite (α). When the content of the polyfunctional acrylate (D) is too large, a transfer material having an active energy ray-curable resin composition is produced, and the transfer composition is used to transfer the resin composition to the surface of the molded product, thereby This is because when the surface of the molded product is coated with the resin composition, the film forming ability of the resin composition is not sufficient and a tendency to become tacky is observed.

<< Solvent (E) >>
The active energy ray-curable resin composition of the present invention has an inorganic oxide-acrylic resin composite (α), photopolymerization start, in terms of adjusting the viscosity and adjusting the wettability to the molded product to which the active energy ray-curable resin composition is applied. A solvent that can dissolve the agent (C) and the polyfunctional acrylate (D) can be used. Examples of such solvents include ketones such as 2-propanone, 4-methyl-2-pentanone, and cyclohexanone, ethyl acetate, butyl acetate, 1-methoxy-2-propyl acetate, 1,2-diacetoxypropane, and the like. Esters, ethers such as tetrahydrofuran and 1,4-dioxane, and aromatic hydrocarbons such as toluene and xylene.

<< Additive (F) >>
In the active energy ray-curable resin composition of the present invention, various additives can be used for the purpose of improving the physical properties of the cured film. Examples of such additives include an ultraviolet absorber, a stabilizer, an antioxidant, an antiblocking agent, and a leveling agent.

  The active energy ray-curable resin composition of the present invention can be formed into a cured film by applying the active energy ray to the target molded article, drying it, and then irradiating the active energy ray. Although there is no restriction | limiting in particular as said molded article, From the point of the ease of a process, what uses a plastic and paper as a raw material is used preferably. Examples of the plastic include polyethylene terephthalate, polymethyl methacrylate, polycarbonate, cellulose acetate, polyvinyl chloride, polypropylene, and ABS resin. Further, the shape of the molded product is not particularly limited, but a sheet shape, a film shape and the like are preferably used.

  And the application | coating to the said molded article can be performed using a various method. Examples of such a method include a dipping method, a flow coating method, a spray method, a bar coating method, a spin coating method, a gravure coating method, and a roll coating method. Moreover, there is no restriction | limiting in particular also about the drying method, and it can carry out by heating, ventilation, or these combination to such an extent that a deformation | transformation of a molded product does not arise. The drying time at this time is preferably in the range of 1 to 30 minutes.

  The thickness of the resin composition to be applied after drying is preferably in the range of 1 to 50 μm, and more preferably in the range of 1 to 20 μm. If the thickness is too thin, the scratch resistance of the cured film may not be improved. On the other hand, if the thickness is too thick, curing by irradiation with active energy rays tends to take too long.

  The active energy ray-curable resin composition after drying is not sticky even when touched with a finger near room temperature, and has a film-forming ability without tack. Therefore, in this state, the entire molded product containing the applied active energy ray-curable resin composition can be subjected to processing such as printing, transfer, embossing, etc., and this is further molded into another shape. You can also For example, after printing on the resin composition and the molded product, it can be subjected to vacuum forming, pressure forming, vacuum pressure forming, or the like. Furthermore, the molded product thus obtained can be transferred to another molded product or the like.

  As the active energy ray, for example, an electron beam, α ray, β ray, γ ray and the like can be used, and such an active energy ray is, for example, a xenon lamp, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, It can be obtained by using a metal halide lamp, a carbon arc lamp, a tungsten lamp or the like.

Thus, when the active energy ray-curable resin composition of the present invention is irradiated with active energy rays to form a cured film, the specific acrylic resin (A) containing an ethylenically unsaturated group in the side chain. Since the ethylenically unsaturated group causes a polymerization reaction, the cross-linking points are dense, and the cured film has excellent scratch resistance. And since the inorganic oxide fine particle (B) which has colloidal silica as a main component has a metal-oxygen bond like Si-O-, the cured film is further excellent in abrasion resistance. Yes. Further, since the specific acrylic resin (A) and the inorganic oxide fine particles (B) are bonded through the bonding site represented by the following formula (1), the silica fine particles are cured when rubbed. As compared with the case where the specific acrylic resin (A) and the inorganic oxide fine particles (B) are merely mixed, the scratch resistance is remarkably improved.
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]

  Furthermore, at the time of active energy ray irradiation, neither the specific acrylic resin (A) nor the inorganic oxide fine particles (B) contributes to curing shrinkage in the main chain portion. For this reason, when making a composition into a cured film, even if it is a case where the molded article with which this was apply | coated consists of a thin sheet | seat, generation | occurrence | production of curl can be suppressed. Moreover, even when the molded product is not a sheet, it is possible to effectively prevent the occurrence of deviation and peeling of the cured film.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the examples, “parts” and “%” mean weight standards.

[Example 1]
(Production of specific acrylic resin (A))
A monomer having an epoxy group and one ethylenically unsaturated group as a monomer component [i] in a 500 mL flask equipped with a stirrer, reflux condenser, nitrogen inlet, thermometer, and dropping funnel (A1): 50 parts of glycidyl methacrylate (manufactured by Mitsubishi Rayon Co., Ltd., Acryester G), another monomer having one ethylenically unsaturated group (a2): 1 part of methyl methacrylate, 75 parts of butyl acetate as a solvent After adding nitrogen and replacing with nitrogen, 1.6 parts of lauryl mercaptan was added as a chain transfer agent, and 0.52 part of 2,2-azobisdimethylvaleronitrile (manufactured by Otsuka Chemical Co., Ltd., ADVN) was added as a polymerization initiator, The reaction was started at a temperature of 65 ° C. After 3 hours, 0.26 parts of the above polymerization initiator was added and reacted for another 3 hours, then the temperature was raised to 100 ° C., this state was maintained for 0.5 hours, and then cooled to 70 ° C. 78 parts of 1-methoxy-2-propyl acetate was added, and a polymer (a3) having an epoxy group obtained by copolymerizing the monomer component [i] was obtained. The epoxy equivalent of the polymer (a3) having this epoxy group was 150.

While bubbling this into the air, 0.06 part of 4-methoxyhydroquinone was added as a polymerization inhibitor and the temperature was raised to 100 ° C., and 0.77 part of triphenylphosphine was added as a catalyst to form a reaction system. As a compound (a4) having a carboxyl group and a (meth) acryloyl group placed in a dropping funnel, 25 parts of acrylic acid was added dropwise over 30 minutes. After completion of the dropwise addition, the reaction system was heated to a temperature of 115 ° C. to carry out a reaction for adding acrylic acid to the specific polymer (a3). In this reaction, the amount of acrylic acid in the reaction system is tracked by measuring the acid value, and when 97 mol% or more of the charged acrylic acid is consumed, the reaction is terminated and cooled to room temperature. . The acrylic resin (A) thus obtained was added with 347 mmoles of 97 to 100 mol% (337 to 347 mmol%) of hydroxyl groups to the specific polymer (a3) by addition of acrylic acid. The number average molecular weight was 3.7 × 10 ³ and the weight average molecular weight was 1.7 × 10 ⁴ in the measurement by the evaluation method described later.

(Production of reaction product (A-a5))
Next, 3-isocyanatopropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., KBE-9007) is used as the compound (a5) having an isocyanate group and an alkoxysilyl group in the reaction system for producing the specific acrylic resin (A). By adding 0.86 part dissolved in 1.5 part of 1-methoxy-2-propylacetate and adding 0.03 part of dibutyltin dilaurate as a catalyst and reacting at a temperature of 80 ° C. for 2 hours, A reaction product (A-a5) was obtained. In addition, when the liquid after completion | finish of reaction was titrated with the amine, the isocyanate group was not recognized.

(Production of inorganic oxide-acrylic resin composite (α))
Colloidal dispersed in 4-methyl-2-pentanone as inorganic oxide fine particles (B) mainly composed of colloidal silica after the reaction system containing the reaction product (A-a5) is gradually cooled to room temperature. 168 parts of silica (manufactured by Nissan Chemical Industries, MIBK-ST, average particle size 10-15 nm, solid content 30% by weight), 0.065 parts of water, 0.010 parts of aluminum acetylacetonate as a catalyst, as a polymerization inhibitor 4-methoxyphenol 0.06 part was added, and it hydrolyzed at the temperature of 70 degreeC for 4 hours, and obtained the inorganic oxide-acrylic-type resin composite ((alpha)).

(Production of active energy ray-curable resin composition)
To 10 parts of the inorganic oxide-acrylic resin composite (α), 0.064 part of 1-hydroxycyclohexyl phenyl ketone (Ciba Japan Co., Ltd., Irgacure 184) is added as a photopolymerization initiator (C). The active energy ray-curable resin composition of the invention was obtained.

[Comparative Example 1]
The activity of Comparative Example 1 was the same as Example 1 except that the reaction product (A-a5) was not produced and the specific acrylic resin (A) and the inorganic oxide fine particles (B) were simply mixed. An energy ray curable resin composition was obtained. That is, although the active energy ray-curable resin composition of Comparative Example 1 has the inorganic oxide fine particles (B), the specific acrylic resin (A) and the inorganic oxide fine particles (B) They are not bonded via the binding site represented by formula (1).

[Comparative Example 2]
The active energy ray-curable resin composition of Comparative Example 2 was obtained in the same manner as in Example 1 except that the reaction product (A-a5) was not produced and the inorganic oxide fine particles (B) were not used. That is, the active energy ray-curable resin composition of Comparative Example 2 does not contain the inorganic oxide fine particles (B).

  Pot life and film-forming properties (tack) of the active energy ray-curable resin compositions of Example 1 and Comparative Examples 1 and 2 thus obtained, pencil hardness and scratch resistance of these cured films, The curl (degree of warpage) in the film covered with this cured film was measured and evaluated by the following method. These results are also shown in Table 1 below.

[Pot life]
Each active energy ray-curable resin composition was stored in the dark at room temperature (25 ° C.), and the period until gelation was observed visually was measured.

[Film formation (tack)]
Each active energy ray-curable resin composition was applied to a PET film base material (manufactured by Toray Industries Inc., Lumirror, thickness 100 μm) using a # 16 bar coater so that the thickness after drying was 7 μm. It was dried at a temperature of 0 ° C. for 2 minutes. Touch the surface of the active energy ray-curable resin composition after drying with a finger to check the presence or absence of tack. If there is no tack, the film formability is good (O). (×) was evaluated.

〔Pencil hardness〕
After evaluating the film-forming property, each active energy ray-curable resin composition is irradiated with ultraviolet rays so that the irradiation energy at a wavelength of 365 nm is 250 or 500 mJ / cm ² and cured. A cured film was produced. And the pencil hardness of these cured films was measured according to JIS K5600-5-4.

[Abrasion resistance]
Among the cured films produced in the above-mentioned pencil hardness section, the haze of the cured film before and after the wear test was measured for those irradiated with ultraviolet rays so that the ultraviolet irradiation energy at a wavelength of 365 nm was 250 mJ / cm ^2. (Δhaze) was evaluated. The wear test was performed using the wear wheel method according to JIS K-5600-5-9 under the conditions of a wear wheel CS-10F, a load of 1 kg, and a rotation speed of 200 times. The haze of the cured film was measured in accordance with JIS K-7105, and the difference in haze before and after the wear test was calculated to obtain Δ haze (unit:%). In addition, it has shown that it is excellent in scratch resistance, so that the value of (DELTA) haze is small.

〔curl〕
Each active energy ray-curable resin composition was previously placed on a PET film substrate (Toyobo Co., Ltd., Cosmo Shine A4300, thickness 38 μm, A4 size) flattened by placing a weight on it for one day. Using a bar coater, it was applied to a thickness of 4 μm after drying, dried at 80 ° C. for 3 minutes, and then irradiated with ultraviolet rays so that the irradiation energy at a wavelength of 365 nm was 500 mJ / cm ^2. Cured. Thus, a hard coat film in which one surface of the film was covered with the cured film was produced. The hard coat film was left overnight under the conditions of a temperature of 23 ° C. and a humidity of 50 RH%, then cut into a size of 10 cm × 10 cm, and the warp with respect to the center of the four corners of the film was measured using a ruler. The average of the warp was taken as the curl value (mm). Note that the smaller the curl value, the smaller the warp and the less the shrinkage on curing due to ultraviolet irradiation.

  From the above results, the specific acrylic resin (A) containing an ethylenically unsaturated group in the side chain and the inorganic oxide fine particles (B) mainly composed of colloidal silica are represented by the above formula (1). The active energy ray-curable resin composition of Example 1 containing an inorganic oxide-acrylic resin composite (α) bonded through a bonding site is excellent in film formability (tack). It can be seen that the cured film has high pencil hardness and excellent scratch resistance and low curl properties.

  On the other hand, the cured film made of the active energy ray-curable resin composition of Comparative Example 1 that does not contain the inorganic oxide-acrylic resin composite (α) may be inferior in scratch resistance and low curl properties. Recognize. Further, in Comparative Example 2 which does not have the inorganic oxide fine particles (B) itself containing colloidal silica as a main component, the film-forming property (tack) is poor and the scratch resistance of the cured film is an example. The result was extremely inferior to one product.

  The active energy ray-curable resin composition of the present invention can form a cured film having excellent pot life and film-forming properties (tack), high pencil hardness, excellent scratch resistance and low curl properties. Therefore, the active energy ray-curable resin composition of the present invention is useful as various coating agents.

Claims (10)

An acrylic resin (A) containing an ethylenically unsaturated group in the side chain and an inorganic oxide fine particle (B) mainly composed of colloidal silica are bonded via a bonding site represented by the following formula (1). An active energy ray-curable resin composition comprising an inorganic oxide-acrylic resin composite (α) formed by bonding and a photopolymerization initiator (C).
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]   Polymer having epoxy group obtained by polymerizing monomer component [i] containing monomer (a1) having acrylic group (A) having epoxy group and one ethylenically unsaturated group The active energy ray-curable resin composition according to claim 1, wherein the compound (a4) having a carboxyl group and a (meth) acryloyl group is added to (a3).   The monomer component [i] contains the monomer (a1) and another monomer (a2) having one ethylenically unsaturated group. 2. The active energy ray-curable resin composition according to 2.   The weight average molecular weight of acrylic resin (A) is 10,000-100,000, The active energy ray-curable resin composition as described in any one of Claims 1-3 characterized by the above-mentioned.   The average particle diameter of inorganic oxide microparticles | fine-particles (B) is 10-100 nm, The active energy ray curable resin composition as described in any one of Claims 1-4 characterized by the above-mentioned.   The activity according to any one of claims 1 to 5, wherein the compounding amount of the inorganic oxide fine particles (B) is 5 to 400 parts by weight with respect to 100 parts by weight of the acrylic resin (A). Energy ray curable resin composition. A method for producing an active energy ray-curable resin composition according to claim 1,
[I] A polymer (a3) having an epoxy group obtained by polymerizing a monomer component [i] containing a monomer (a1) having an epoxy group and one ethylenically unsaturated group Adding the compound (a4) having a carboxyl group and a (meth) acryloyl group to produce an acrylic resin (A);
[II] a step of producing a reaction product (A-a5) by reacting an isocyanate group of a compound (a5) having an isocyanate group and an alkoxysilyl group with the hydroxyl group generated during the addition reaction;
[III] By reacting the alkoxysilyl group in the reaction product (A-a5) with the hydroxyl group in the inorganic oxide fine particles (B) mainly composed of colloidal silica, the acrylic resin (A) and the inorganic resin are reacted. A step of producing an inorganic oxide-acrylic resin composite (α) in which the oxide fine particles (B) are bonded via a bonding site represented by the following formula (1);
[IV] A method for producing an active energy ray-curable resin composition comprising a step of mixing a photopolymerization initiator (C) together with the inorganic oxide-acrylic resin composite (α).
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ] A method for producing an active energy ray-curable resin composition according to claim 1,
[I] A polymer (a3) having an epoxy group obtained by polymerizing a monomer component [i] containing a monomer (a1) having an epoxy group and one ethylenically unsaturated group Adding the compound (a4) having a carboxyl group and a (meth) acryloyl group to produce an acrylic resin (A);
[V] A step of producing a reaction product (B-a5) by reacting a hydroxyl group in the inorganic oxide fine particles (B) with an isocyanate group and an alkoxysilyl group in the compound (a5) having an alkoxysilyl group; ,
[VI] By reacting the isocyanate group in the reaction product (B-a5) with the hydroxyl group in the acrylic resin (A), the acrylic resin (A) and the inorganic oxide fine particles (B) A step of producing an inorganic oxide-acrylic resin composite (α) formed by binding via a binding site represented by the following formula (1);
[VII] A method for producing an active energy ray-curable resin composition comprising a step of mixing a photopolymerization initiator (C) together with the inorganic oxide-acrylic resin composite (α).
—O—Si—R ¹ —NHCOO— (1)
In [the formula (1), R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms. ]   A molded article comprising a cured film, wherein at least a part of the surface is covered with the cured film of the active energy ray-curable resin composition according to any one of claims 1 to 6.   The molded article provided with the cured film according to claim 9, wherein the molded article is a plastic film.