JP2012031434A - Method for producing photocurable (meth)acrylic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a photocurable (meth)acrylic resin having ultraviolet absorptivity and long term weatherability, showing excellent solubility in various solvents, many resins and monomers, formable of a transparent coating film without precipitation even at a low temperature, and desirable in the viewpoint of uniform dispersion and solubility in case of being compounded in a wide range of the photocurable (meth)acrylic resins and the like.SOLUTION: The method for producing the photocurable (meth)acrylic resin having a specific component unit comprises: a step of forming a precursor containing a specific component unit by separately adding a specific compound (a1), a specific compound (b2) and another monomer (c1) copolymerizable with either of the compounds (a1) and (b2), reacting and copolymerizing them using a radical polymerization initiator several times so as to finally get a predetermined amount ratio, and a step (2) of reacting the precursor with the specific compound (b1).

Description

  The present invention relates to a method for producing a photocurable (meth) acrylic resin.

  Conventionally, a method for improving light resistance and weather resistance by blending an ultraviolet absorber with a photocurable resin composition is known. This method has a drawback that the ultraviolet absorbent bleeds out from the resin, and the sustainability of the effect is difficult to continue.

  In contrast, in Japanese Patent No. 2963029 (Nippon Shokubai, Patent Document 1), 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole and cycloalkyl (meth) acrylate A coating composition containing a copolymer obtained by copolymerizing a cycloalkyl group-containing unsaturated monomer such as hydroxyethyl (meth) acrylate and the like with a hydroxyl group-containing unsaturated monomer is disclosed. . In this copolymer, the ultraviolet absorber is incorporated in the copolymer, and there is no problem of bleeding out of the ultraviolet absorber.

  However, this composition is a two-component coating composition obtained by blending the above copolymer (hydroxyl group-containing acrylic polyol) and an isocyanate group-containing crosslinking agent such as a polyisocyanate compound or a modified product thereof. That is, the above-mentioned ultraviolet absorber-containing copolymer itself does not have photocurability, and can be combined with a polyisocyanate compound as a crosslinking agent to form a cured coating film by a two-component urethane curing reaction. It is a coalescence and cannot be used for a photocurable resin composition.

Therefore, the present inventors repeated intensive studies to solve the above problems,
(A) In the obtained copolymer (photocurable (meth) acrylic resin), at least the side chain terminal is not subjected to a copolymerization reaction together with the ultraviolet absorbing compound component unit (A) having ultraviolet absorbing properties. When a photopolymerizable polyfunctional (meth) acryloyl group-containing compound component unit (B) having an unreacted (meth) acryloyl group is present, the photocurable acrylic resin is at least copolymerized. It has photocurability because it contains a photocurable (meth) acryloyl group in the body side chain,
(B) The photocurable resin composition containing the photocurable acrylic resin has a long-term weather resistance because the photocurable acrylic resin is reactively immobilized in the cured product by the curing reaction of the composition. That can be granted,
(C) In addition, this photo-curable (meth) acrylic resin is different from various solvents, UV absorbers that are poorly soluble in resins and monomers, ketones, esters, ethers, various aromatic solvents, and many Since the solubility with the resin and the monomer is good, a transparent coating film can be formed without precipitation even at low temperatures, and it can be uniformly dispersed and dissolved by blending with a wide range of photocurable (meth) acrylate resins. In addition, since the solubility in the resin and the monomer is good, the ratio of the ultraviolet absorbing component in the composition can be increased, so that the ultraviolet absorbing performance can be further improved, and the present invention is completed. It came.

  The reactive ultraviolet absorber (monomer) 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole (trade name “RUVA-93” manufactured by Otsuka Chemical Co., Ltd.) As an example of using as a kind of monomer for copolymerization, a copolymer of the monomer and cyclohexyl acrylate (JP-A-9-3134, Patent Document 2) and the like can be mentioned.

  In addition, JP-A-6-88065 (Patent Document 3) discloses an ultraviolet absorber in which a polymerizable unsaturated double bond is bonded to the skeleton of a benzotriazole ultraviolet absorber through an alkylene chain via a urethane bond. And an ultraviolet absorbing composition containing the same.

  Japanese Patent Application Laid-Open No. 6-88066 (Patent Document 4) discloses an ultraviolet absorber having an unsaturated double bond that can be polymerized via a urethane bond in the skeleton of a benzophenone ultraviolet absorber, and an ultraviolet absorber containing the same. A composition is disclosed.

  Further, as ultraviolet absorbers and related technologies, JP-A-6-128502 (Patent Document 5, corresponding patent No. 3223459), JP-A-61-2236805 (Patent Document 6), JP-A-4 -106161 (Patent Document 7), JP-A-5-65316 (Patent Document 8), JP-A-10-130456 (Patent Document 9), JP-A-2001-342439 (Patent Document 10), and the like. Can be mentioned.

Patent No. 2963029 JP-A-9-3134 JP-A-6-88065 JP-A-6-88066 JP-A-6-128502 Japanese Patent Laid-Open No. Sho 61-236805 JP-A-4-106161 JP-A-5-65316 JP-A-10-130456 JP 2001-342439 A

  The present invention seeks to solve the problems associated with the prior art as described above, has ultraviolet absorptivity, has long-term weather resistance, and is soluble in various solvents, resins and monomers. Unlike inferior reactive ultraviolet absorbers, it has excellent solubility in ketones, esters, ethers, aromatic solvents, many resins and monomers, and can form a transparent coating without precipitation even at low temperatures. An object of the present invention is to provide a photocurable (meth) acrylic resin that can be blended in a wide range of photocurable (meth) acrylate resins and the like and can be uniformly dispersed and dissolved.

Another object of the present invention is to provide a UV-absorbing photocurable resin composition having the above effects.
The present invention also provides a weather-resistant film formed from the above composition and having physical properties such as ultraviolet absorption, hardness, steel wool resistance, and curl resistance, a substrate coated with the film, and a coated film. It is an object.

  Another object of the present invention is to provide a method for absorbing ultraviolet light by forming a specific weather-resistant film on the surface of a substrate.

The photocurable (meth) acrylic resin according to the present invention is
(A) a UV-absorbing compound component unit derived from a (meth) acryloyl group-containing UV-absorbing compound (a1) having a UV-absorbing compound skeleton and a (meth) acryloyl group, and (B) (meth) acryloyl Photopolymerizable (meth) acryloyl group-containing compound having a (meth) acryloyl group at the side chain terminal derived from two types of compounds (b1) and (b2) having a group and a functional group via a urethane bond or an ester bond Component units;
(C) (meth) acryloyl group-containing UV-absorbing compound (a1) that forms the component unit (A), and a compound that induces a photopolymerizable (meth) acryloyl group-containing compound that forms the component unit (B) (B2)
A component unit derived from another monomer (c1) copolymerizable with any of
It is characterized by containing.

  In the present invention, the (meth) acryloyl group-containing ultraviolet absorbing compound (a1) is 2- [2′-hydroxy-5 ′-((meth) acryloyloxyethyl) phenyl] -2H-benzotriazole. It is preferable in terms of easy availability of raw materials and excellent performance of the copolymer in view of the above-mentioned purpose.

In the present invention, the photopolymerizable (meth) acryloyl group-containing compound component unit (B) is at least one selected from the group consisting of the following general formulas (BI) to (B-III) ( It is preferable in terms of the performance of the copolymer, the availability of raw materials, and the ease of synthesis in inducing the (meth) acryloyl group-containing compound component unit (B).
Formula (I):

一般式（Ｂ−II）：

General formula (B-II):

一般式（Ｂ−III）：

General formula (B-III):

［式（Ｂ−Ｉ）、（Ｂ−II）、（Ｂ−III）中、ＲはＨまたはＣＨ₃を示す。］
本発明では、上記光重合性（メタ）アクリロイル基含有化合物成分単位（Ｂ）が、予め共重合体（前駆体）中に導入された２−（メタ）アクリロイルオキシエチルイソシアネート単位中のイソシアネート基（−ＮＣＯ）と、２−ヒドロキシエチル(メタ)アクリレートのヒドロキシル基（−ＯＨ）とのウレタン化反応により形成され、一般式（Ｂ−II）で表されることが好ましい。

[In the formulas (BI), (B-II) and (B-III), R represents H or CH ₃ . ]
In the present invention, the photopolymerizable (meth) acryloyl group-containing compound component unit (B) is an isocyanate group in a 2- (meth) acryloyloxyethyl isocyanate unit introduced in advance into a copolymer (precursor) ( -NCO) is preferably formed by a urethanization reaction between 2-hydroxyethyl (meth) acrylate hydroxyl group (-OH) and represented by the general formula (B-II).

  In the present invention, the photopolymerizable (meth) acryloyl group-containing compound component unit (B) is subjected to an esterification reaction between a (meth) acrylic acid unit previously introduced into the copolymer and glycidyl (meth) acrylate. It is preferably formed and represented by the general formula (B-II).

In the present invention, the photopolymerizable (meth) acryloyl group-containing compound component unit (B) is a (meth) acrylic acid unit previously introduced into the copolymer, and a glycidyl ether of 4-hydroxybutyl (meth) acrylate. Is formed by an esterification reaction with general formula (B-III)
It is preferable to be represented by

  The photocurable (meth) acrylic resin according to the present invention has a number average molecular weight (Mn) of the photocurable (meth) acrylic resin measured by gel permeation chromatography (GPC) of 800 to 7,000, The weight average molecular weight (Mw) is preferably 3,000 to 50,000, and the molecular weight distribution (Mw / Mn) is preferably 2 to 9.

  The photocurable (meth) acrylic resin according to a more preferred embodiment of the present invention has a number average molecular weight (Mn) of 1,000 to 5,000 as measured by gel permeation chromatography. It is desirable that the weight average molecular weight (Mw) is 4,000 to 30,000 and the molecular weight distribution (Mw / Mn) is 2.5 to 7.

The photocurable (meth) acrylic resin according to the present invention is
When the total [(A) + (B) + (C)] of the component unit (A), the component unit (B) and the component unit (C) constituting the photocurable (meth) acrylic resin is 100% by weight ,
UV-absorbing compound component unit (A) 5 to 90% by weight,
The photopolymerizable (meth) acryloyl group-containing compound component unit (B) is 5 to 80% by weight,
The component unit (C) derived from the other monomer (c1) is preferably 1 to 80% by weight.

In a further preferred embodiment of the present invention, the sum of the component unit (A), the component unit (B) and the component unit (C) constituting the photocurable (meth) acrylic resin [(A) + (B) + (C) ] Is 100% by weight,
UV-absorbing compound component unit (A) is 10 to 80% by weight,
The photopolymerizable (meth) acryloyl group-containing compound component unit (B) is 15 to 70% by weight,
The component unit (C) derived from the other monomer (c1) is preferably 5 to 70% by weight.

In a particularly preferred embodiment of the present invention, the sum of the component unit (A), the component unit (B) and the component unit (C) constituting the photocurable (meth) acrylic resin [(A) + (B) + (C )] Is 100% by weight,
UV-absorbing compound component unit (A) is 20 to 60% by weight,
The photopolymerizable (meth) acryloyl group-containing compound component unit (B) is 25 to 60% by weight,
The component unit (C) derived from the other monomer (c1) is preferably 10 to 55% by weight.

The ultraviolet-absorbing photocurable resin composition according to the present invention includes the photocurable (meth) acrylic resin (d1) described above,
A photocurable (meth) acryloyl group-containing resin (e1);
Compared to the resin (e1), a lower molecular weight photocurable monomer or its oligomer (f1),
A photopolymerization initiator (g1);
Contains.

  In the ultraviolet-absorbing photocurable resin composition according to the present invention, the photocurable (meth) acryloyl group-containing resin (e1) is an epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, or poly It is desirable that it is at least one selected from the group consisting of ether (meth) acrylates.

In the ultraviolet-absorbing photocurable resin composition according to the present invention, the photocurable (meth) acryloyl group-containing resin (e1) has a number average molecular weight (Mn) of 300 to 300 measured by gel permeation chromatography. 50000, and
It is desirable that it is at least one selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate and polyether (meth) acrylate.

In a more preferred embodiment, the photocurable (meth) acryloyl group-containing resin (e1) has a number average molecular weight (Mn) measured by gel permeation chromatography of 1,000 to 10,000, and
It is desirable in terms of hardness and steel wool resistance that it is at least one selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate and polyether (meth) acrylate.

  In a more preferred embodiment of the ultraviolet-absorbing photocurable resin composition according to the present invention, the molecular weight of the photocurable monomer having a lower molecular weight than the component (e1) or its oligomer (f1) is 100 to 2000, More preferably, a photocurable monomer of 150 to 1000 or an oligomer thereof is desirable in terms of hardness and steel wool resistance.

  In a preferred embodiment of the ultraviolet absorbing photocurable resin composition according to the present invention, it is desirable that the photopolymerization initiator (g1) contains at least an acylphosphine oxide or a thioxanthone.

The weather-resistant film according to the present invention is formed from the ultraviolet-absorbing photocurable resin composition described in any of the above.
The substrate according to the present invention is a substrate (coated substrate) coated with a weather-resistant film formed from the photocurable resin composition described in any one of the above.

  The coated film according to the present invention is characterized in that the surface of a plastic film is coated with an ultraviolet absorbing coating comprising the ultraviolet absorbing photocurable resin composition described in any of the above.

  The ultraviolet absorption method according to the present invention is characterized in that a weather-resistant film made of the ultraviolet-absorbing photocurable resin composition described in any one of the above is formed on a substrate surface.

  The photocurable (meth) acrylic resin according to the present invention has a photopolymerizable (meth) acryloyl group-containing compound having an unreacted (meth) acryloyl group that has not been subjected to a copolymerization reaction at a side chain end. Since the component unit (B) is present, this photocurable acrylic resin has photocurability.

  In addition, the photocurable resin composition containing the photocurable acrylic resin is a bleed of a component having an ultraviolet absorbing function by the reaction and immobilization of the photocurable acrylic resin in the cured product by a photocuring reaction. There is no out and long-term weather resistance can be imparted.

  In addition, this photo-curable (meth) acrylic resin dissolves well in solvents, resins, and monomers, unlike UV absorbers that are poorly soluble in various solvents, resins, and monomers, so it is transparent without precipitation even at low temperatures. Can be formed and can be uniformly dispersed and dissolved by blending with a wide variety of photocurable (meth) acrylate resins.

FIG. 1 is an IR spectrum of the photocurable acrylic copolymer B-1 obtained in Example 1. FIG. 2 is an IR spectrum of the photocurable acrylic copolymer B-2 obtained in Example 2. FIG. 3 is an IR spectrum of the photocurable acrylic copolymer B-3 obtained in Example 3. FIG. 4 is an IR spectrum of the photocurable acrylic copolymer B-4 obtained in Example 4. FIG. 5 is an IR spectrum of the photocurable acrylic copolymer B-5 obtained in Example 5. FIG. 6 is an IR spectrum of the photocurable acrylic copolymer B-6 obtained in Example 6. FIG. 7 is an IR spectrum of the photocurable acrylic copolymer B-7 obtained in Example 7. FIG. 8 is an IR spectrum of the photocurable acrylic copolymer B-8 obtained in Example 8. FIG. 9 is a GPC chromatogram of the photocurable acrylic copolymer B-1 obtained in Example 1. FIG. 10 is a GPC chromatogram of the photocurable acrylic copolymer B-2 obtained in Example 2. FIG. 11 is a GPC chromatogram of the photocurable acrylic copolymer B-3 obtained in Example 3. FIG. 12 is a GPC chromatogram of the photocurable acrylic copolymer B-4 obtained in Example 4. FIG. 13 is a GPC chromatogram of the photocurable acrylic copolymer B-5 obtained in Example 5. FIG. 14 is a GPC chromatogram of the photocurable acrylic copolymer B-6 obtained in Example 6. FIG. 15 is a GPC chromatogram of the photocurable acrylic copolymer B-7 obtained in Example 7. FIG. 16 is a GPC chromatogram of the photocurable acrylic copolymer B-8 obtained in Example 8.

  Hereinafter, the photocurable (meth) acrylic resin {(meth) acryloyl group-containing photocurable acrylic resin copolymerized with the reactive ultraviolet absorber according to the present invention. }, The photocurable resin composition containing the resin and the weather-resistant film made of the composition will be specifically described.

[Photocurable (meth) acrylic resin (d1)]
The photocurable (meth) acrylic resin (also referred to as copolymer, resin (d1), etc.) according to the present invention contains the following component units (A), (B), and (C).
Ingredient unit (A) :
A UV-absorbing compound component unit (A) derived from a (meth) acryloyl group-containing UV-absorbing compound (a1) having a UV-absorbing compound skeleton and a (meth) acryloyl group. Ingredient unit (B) :
Photopolymerizability having a (meth) acryloyl group at the side chain terminal derived from two compounds (b1) and (b2) having a (meth) acryloyl group and a functional group via a urethane bond or an ester bond An acryloyl group-containing compound component unit (B).
Component unit (C) :
The (meth) acryloyl group-containing UV-absorbing compound (a1) that forms the component unit (A), and the compound (b2) that induces the photopolymerizable (meth) acryloyl group-containing compound that forms the component unit (B). Component unit (C) derived from other monomer (c1) copolymerizable with any of the above.

  In the photocurable (meth) acrylic resin according to the present invention, the sum of the component unit (A), the component unit (B) and the component unit (C) constituting the resin [(A) + (B) + (C )] Is 100% by weight, the UV-absorbing compound component unit (A) is usually 5 to 90% by weight, preferably 10 to 80% by weight, particularly preferably 20 to 60% by weight, and is photopolymerizable. The (meth) acryloyl group-containing compound component unit (B) is usually 5 to 80% by weight, preferably 15 to 70% by weight, particularly preferably 25 to 60% by weight, and is derived from the other monomer (c1). The component unit (C) is usually present in a proportion of 1 to 80% by weight, preferably 5 to 70% by weight, particularly preferably 10 to 55% by weight. It is desirable in terms of physical properties.

  In the photocurable (meth) acrylic resin of the present invention, each component unit may be arranged in any form such as random, block, alternating copolymer, etc., so that the total amount is in the above range. Usually, it is randomly arranged in any order.

  In addition, when the amount of the component unit (A) in the photocurable (meth) acrylic resin is less than the above range, there is a tendency that the ultraviolet absorptivity is lowered, and when the amount exceeds the above range, the component unit (B). There is a tendency for the amount to decrease and the photocurability to be poor.

  Moreover, when the amount of the component unit (B) in the photocurable (meth) acrylic resin is less than the above range, the photocurability tends to be inferior, and when the amount exceeds the above range, the amount of the component unit (A) Tends to decrease, and the ultraviolet absorptivity tends to be low.

  Further, when the amount of the component unit (C) in the photocurable (meth) acrylic resin is less than the above range, the hardness tends to be low, and when the amount exceeds the above range, the amount of the component unit (A) or There is a tendency that the amount of the component unit (B) is decreased and the ultraviolet absorptivity is lowered or the photocurability is inferior.

  In the photocurable (meth) acrylic resin according to the present invention, the number average molecular weight (Mn) of the photocurable (meth) acrylic resin measured by gel permeation chromatography (GPC) is usually 800 to 7,000, Preferably, it is 1,000 to 5,000, and the weight average molecular weight (Mw) is usually 3,000 to 50,000 (50,000), preferably 4,000 to 30,000 (30,000), and the molecular weight The distribution (Mn / Mw) is usually 2 to 9, preferably 2.5 to 7 in terms of making the viscosity and viscosity appropriate when applying and processing the photocurable resin composition on a substrate. preferable.

  Hereinafter, each component unit (A), (B), (C) and the compound (a1), (b1) or (b2), (c1), etc. which can form (derivatize) these component units will be described.

<Ultraviolet-absorbing compound component unit (A) and compound (a1) capable of deriving it>
The ultraviolet absorbing compound component unit (A) (component unit (A)) has an ultraviolet absorbing compound skeleton and a (meth) acryloyl group in the side chain.
The UV-absorbing compound skeleton is required to have an absorption wavelength of light of about 300 to 400 nm, a large absorption coefficient, and not to be decomposed by light or heat. The UV-absorbing compound skeleton includes aromatic derivatives (eg, derivatives such as benzene and naphthalene), chromophores (eg, C = N, N = N, N = O, C = O, etc.) and assistants. It is derived from a compound having a color group (eg, NH ₂ , OH, SO ₃ H, COOH, etc.) and often has a function of stabilizing by absorbing UV and causing inversion within the molecule ( http://www.osaka-kyoiku.ac.jp/~sawada/plastic/kaisitu.html#head).

  Examples of such UV-absorbing compound skeletons include skeletons derived from UV absorbers described in JP 2001-64504 A, for example, benzophenone-based, benzotriazole-based, phenyl salicylate-based, triazine. Type, cyanoacrylate type and the like. A preferable ultraviolet absorber skeleton is a benzotriazole-based ultraviolet absorber skeleton.

  This component unit (A) is derived from the (meth) acryloyl group-containing ultraviolet absorbing compound (a1). More specifically, an ultraviolet-absorbing substance serving as an ultraviolet-absorbing compound skeleton {eg, 2- [2′-hydroxy-5 ′-(hydroxyethyl) phenyl]-having a benzotriazole-based skeleton that is an ultraviolet-absorbing skeleton) — 2H-benzotriazole} and a (meth) acryloyl group-containing substance {example: (meth) acrylic acid ester} derived from a (meth) acryloyl group-containing UV-absorbing compound (a1) and the like .

Specifically, for example, (I): 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole [trade name: RUVA-93, manufactured by Otsuka Chemical Co., Ltd.],
In addition, 2- (2′-hydroxy-3′-t-butyl-5′-methacryloxyethylphenyl) -2H-benzotriazole, 2- [2 ′-(meth) acryloyloxy-5′-methylphenyl] Benzotriazole, 2- [2 ′-(meth) acryloyloxy-5′-t-octylphenyl] benzotriazole, 2- [2 ′-(meth) acryloyloxy-3 ′, 5′-di-t-butylphenyl Benzotriazole compounds such as benzotriazole; 2-hydroxy-4- (methacryloyloxyethoxy) benzophenone, 2-hydroxy-4- (acryloyloxyethoxy) benzophenone, 2-hydroxy-4-methacryloyloxymethylaminobenzophenone, 2-hydroxy -4- (methacryloyloxymethoxy) benzophenone 2-hydroxy-4-methacryloyloxymethylthiobenzophenone, 2- (meth) acryloyloxy-4-methoxybenzophenone, 2- (meth) acryloyloxy-2′-hydroxy-4-methoxybenzophenone, 2,2′-di ( (Meth) acryloyloxy-4-methoxybenzophenone, 2,2′-di (meth) acryloyloxy-4,4′-dimethoxybenzophenone, 2- (meth) acryloyloxy-4-methoxy-2′-carboxybenzophenone, 2- Benzophenone compounds such as hydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone and 2,2′-dihydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone; 2 -(4,6-Dife Triazine compounds such as ru-1,2,5-triazin-2-yl) -5- (methacryloyloxyethoxy) -phenol; cyanoacrylates such as 2-ethylhexyl-2-cyano-3,3-diphenyl (meth) acrylate Compound etc. are mentioned. (Refer to the ultraviolet absorber described in JP 2001-342439 A [0015])

Among these, monomers such as 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, other radical polymerizable monomers (meth) acrylic acid ester (b2) Any of the other monomers (c1) such as styrene, acrylonitrile and the like can be favorably radically copolymerized, and the resulting copolymer or a coating film containing a cured product thereof is excellent in UV absorption, In the point that UV absorber is not volatilized at the time of processing at high temperature, and there is no elution (bleed out) from the coating film surface, and high safety and stable weather resistance can be exhibited for a long time. desirable.
These (meth) acryloyl group-containing UV-absorbing compounds (a1) may be present alone or in combination of two or more in the copolymer.

<Photopolymerizable (meth) acryloyl group-containing compound component unit (B) and compounds (b1) and (b2) for deriving the same>
The photopolymerizable (meth) acryloyl group-containing compound component unit (B) (component unit (B)) has at least a (meth) acryloyl group that is a photopolymerizable functional group at the side chain terminal.

  In the present invention, the photopolymerizable (meth) acryloyl group-containing compound component unit (B) may be at least one selected from the group consisting of the following general formulas (BI) to (B-III) ( The copolymer is preferable in terms of the performance of the copolymer, the availability of raw materials, the ease of synthesis of (meth) acryloyl group induction, and the like.

  Formula (BI):

一般式（Ｂ−II）：

General formula (B-II):

一般式（Ｂ−III）：

General formula (B-III):

［式（Ｂ−I）、（Ｂ−II）、（Ｂ−III）中、ＲはＨまたはＣＨ₃を示す。］

[In the formulas (B-I), (B-II) and (B-III), R represents H or CH ₃ . ]

<(BI)>
The photopolymerizable (meth) acryloyl group-containing compound component unit represented by the above general formula (BI) is preferably a radically polymerizable group (meth) acryloyl group, etc., and a non-radically polymerizable group in advance. A monomer having a functional group such as an isocyanate group (NCO) or the like is used for copolymerization with 2- (meth) acryloyloxyethyl isocyanate or the like (corresponding to the monomer (b2)). The unit (B ′) having a radical polymerizable functional group in the side chain is introduced into a photocurable (meth) acrylic resin-forming copolymer (precursor).

  Other NCO-containing monomers include “Karenz MOI” (2-methacryloyloxyethyl isocyanate) manufactured by Showa Denko KK, “Karenz AOI” (2-acryloyloxyethyl isocyanate) manufactured by Showa Denko KK, “MAI” manufactured by Nippon Paint Co., Ltd. (Methacryloyl isocyanate) and the like.

  Next, it corresponds to a non-radically polymerizable functional group (eg, NCO group) in the obtained copolymer (precursor) and an OH group-containing monomer (monomer (b1) such as 2-hydroxyethyl (meth) acrylate) ) To form a photopolymerizable polyfunctional (meth) acryloyl group-containing compound component unit (B) represented by the above general formula (BI), that is, the component unit (BI) It is desirable to form a photocurable (meth) acrylic resin having). Other examples of OH group-containing monomers include 2HEA (official name: 2-hydroxyethyl acrylate), 2HEMA (official name: 2-hydroxyethyl methacrylate), 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl. (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, lactone-modified 2-hydroxy (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, Polytetramethylene glycol mono (meth) acrylate, poly (ethylene glycol-propylene glycol) mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) (Meth) acrylates, poly (propylene glycol - tetramethylene glycol) mono (meth) acrylate, OH-terminated polyalkylene glycol mono (meth) acrylate and the like.

  This OH group-containing monomer, such as 2-hydroxyethyl (meth) acrylate, has a functional group (eg, OH group) capable of reacting with the non-radically polymerizable functional group (eg, NCO group) and is co-polymerized. It has a (meth) acryloyl group which is a group involved in photocuring to be introduced into the coalescence (precursor).

  In the present invention, an OH group in such an OH group-containing monomer is reacted with an NCO group, which is a non-radically polymerizable functional group in the unit (B ′), to give the above general formula (BI). It is desirable to form a copolymer having the photopolymerizable (meth) acryloyl group-containing compound component unit (B) represented (Example: Examples 1, 2, 5, etc.).

  In this reaction, an isocyanate group (—NCO) which is a non-radically polymerizable functional group in the 2- (meth) acryloyloxyethyl isocyanate unit (B ′) previously introduced into the copolymer (precursor), The component unit (BI) is formed by the urethanization reaction with the hydroxyl group (—OH) of 2-hydroxyethyl (meth) acrylate.

<NCO group-containing component unit (B ′) + 2-hydroxyethyl (meth) acrylate → component unit (
BI)>

なお、光硬化性（メタ）アクリル樹脂の製造に際し、最初から、共重合性モノマーとして、例えば、（メタ）アクリロイル基を２個またはそれ以上有するモノマー［すなわち少なくとも２個の(メタ)アクリロイル基を有する光重合性多官能性（メタ）アクリロイル基含有化合物に相当］を、成分単位（Ｂ−Ｉ）形成用のモノマーとして配合すると、各モノマーの２重結合の解裂が複数箇所で生じて網目状の架橋反応が進行して、硬化等してしまい、所望の光硬化性（メタ）アクリル樹脂は得られない。下記成分単位（Ｂ−II）、（Ｂ−III）の場合もこれと同様である。

In the production of a photocurable (meth) acrylic resin, from the beginning, as a copolymerizable monomer, for example, a monomer having two or more (meth) acryloyl groups [that is, at least two (meth) acryloyl groups. The photopolymerizable polyfunctional (meth) acryloyl group-containing compound] as a monomer for forming the component unit (BI), the double bonds of each monomer are cleaved at a plurality of locations, resulting in a network. The cross-linking reaction progresses and cures, and the desired photocurable (meth) acrylic resin cannot be obtained. The same applies to the following component units (B-II) and (B-III).

  Here, it is noted that “RUVA-93 (Otsuka Chemical)” corresponding to the component unit (a) has an “OH” group on the benzene ring, but 2- It appears that there is virtually no urethanization reaction with (meth) acryloyloxyethyl isocyanate.

  The reason for this is that the reactivity of the phenol OH group and NCO is slow, and because benzotriazole is present near OH, the reactivity is further slow due to steric hindrance, the addition of no urethanization catalyst, and IR after acrylic polymerization From the fact that there is an NCO absorption peak and no abnormal high molecular weight portion is observed in GPC, it is considered that the urethanization reaction does not occur under the acrylic polymerization conditions in the present invention.

<(B-II)>
The photopolymerizable (meth) acryloyl group-containing compound component unit represented by the general formula (B-II) is preferably a radically polymerizable group (meth) acryloyl group, etc. (Meth) acrylic acid, glycidyl (meth) acrylate and the like (monomers (b2)) which are monomers having a functional group such as carboxyl group (COOH) and epoxy group-containing groups (eg glycidyl group, epoxy group) The component (B) forming unit (B ′) may be introduced into the photocurable (meth) acrylic resin-forming copolymer (precursor) using the equivalent) during copolymerization. desirable.

  Next, non-radically polymerizable functional groups in the obtained copolymer (precursor) {Example: COOH group in (meth) acrylic acid} and "(meth) acrylic acid glycidyl ether" are esterified. It is desirable to react to form the photopolymerizable (meth) acryloyl group-containing compound component unit (B) represented by the general formula (B-II).

  This “(meth) acrylic acid glycidyl ether” or the like has a functional group (for example, an epoxy group for COOH) that can be bonded by reacting with the non-radically polymerizable functional group (for example, COOH group). And a (meth) acryloyl group that is a group involved in photocuring to be introduced into the copolymer (precursor).

  In addition, a copolymer (precursor) having a glycidyl group in a side chain is previously formed using “glycidyl (meth) acrylate” which is a monomer having an epoxy group as a non-radically polymerizable functional group, Next, a monomer ((meth) acrylic acid) having a carboxyl group (COOH) which is one of reactive groups with this glycidyl group and also having a (meth) acryloyl group of a photocurable group, etc. Contact may be made to introduce a photocurable group into the copolymer (Example: Examples 3, 4, 6, 8, etc.).

  <Glycidyl (meth) acrylate component unit (B ′) + (meth) acrylic acid → component unit (B-II)>

＜（Ｂ−III）＞
また、上記一般式（Ｂ−III）で表される光重合性（メタ）アクリロイル基含有化合物成分単位は、好ましくは、予め、ラジカル重合性基である（メタ）アクリロイル基などと、非ラジカル重合性の官能基であるカルボキシル基（ＣＯＯＨ）などとを有するモノマーである（メタ）アクリル酸など（化合物（ｂ２）に相当）を共重合時に用いて、成分単位（Ｂ）形成用のユニット（Ｂ'）である（メタ）アクリル酸単位などを、光硬化性（メタ）アクリル樹脂形成性の共重合体（前駆体）中に導入しておくことが望ましい。

<(B-III)>
In addition, the photopolymerizable (meth) acryloyl group-containing compound component unit represented by the general formula (B-III) is preferably a radically polymerizable group (meth) acryloyl group or the like in advance, and non-radical polymerization. A unit (B) for forming a component unit (B) using (meth) acrylic acid or the like (corresponding to the compound (b2)), which is a monomer having a carboxyl group (COOH), which is a functional functional group, at the time of copolymerization It is desirable to introduce a (meth) acrylic acid unit or the like that is') into a photocurable (meth) acrylic resin-forming copolymer (precursor).

  The copolymer (precursor) having a (meth) acrylic acid unit as the unit (B ′) is a radically polymerizable (meth) acryloyl which becomes a photocurable group in the precursor, particularly in the side chain. It does not yet have a group or the like (the precursor (B ′) is the same in the case of (BI) and (B-II)).

  (Meth) acrylic acid capable of forming a (meth) acrylic acid unit corresponds to “compound (b2)”. This compound (b2) unit, that is, a (meth) acrylic acid unit is a compound (b1) containing a “glycidyl group and a (meth) acryloyl group represented by“ glycidyl ether of 4-hydroxybutyl (meth) acrylate ”and the like. To form a photopolymerizable (meth) acryloyl group-containing compound component unit (B).

  In addition, without copolymerizing the precursor unit (B ′), (meth) acrylic acid corresponding to “compound (b2)” and “4-hydroxybutyl (meth) acrylate” corresponding to “compound (b1)” The reaction product with “glycidyl ether” can be referred to as “photopolymerizable polyfunctional (meth) acryloyl group-containing compound (BX) having at least two (meth) acryloyl groups”, which is radically polymerizable at both ends. Since it has a (meth) acryloyl group, itself cannot be used as a monomer for polymerization.

  During the production of the photocurable (meth) acrylic resin, if these are radically polymerized using the compound (BX) together with the monomer (a) and the monomer (c), a crosslinking reaction by the compound (BX) also occurs and the product Will harden.

In the present invention, next, in the obtained copolymer (precursor), more specifically, a non-radically polymerizable functional group (eg, COOH group) in the (meth) acrylic acid unit, and “4-hydroxy Forming a photopolymerizable (meth) acryloyl group-containing compound component unit (B) represented by the above general formula (B-III) by an esterification reaction with glycidyl ether of butyl (meth) acrylate, etc., That is, it is desirable to form a photocurable (meth) acrylic resin having the component unit (B-III).

  “Glycidyl ether of 4-hydroxybutyl (meth) acrylate” which is a compound containing a glycidyl group and a (meth) acryloyl group can react with the non-radically polymerizable functional group (eg, COOH group). It has a functional group (eg, epoxy group, glycidyl group) and has a (meth) acryloyl group which is a group involved in photocuring to be introduced into the copolymer (precursor).

  In the present invention, the glycidyl group contained in such “4-hydroxybutyl (meth) acrylate glycidyl ether” or the like and the carboxyl group (COOH) in the unit (B ′) are subjected to an esterification reaction. It is desirable to form a copolymer having a photopolymerizable (meth) acryloyl group-containing compound component unit (B) represented by the formula (B-III) (eg, Example 7).

  <COOH group-containing component unit (B ′) + “glycidyl ether of 4-hydroxybutyl (meth) acrylate” → component unit (B-III)>

<Component unit (C) and compound (c1) capable of deriving it>
Examples of the “other monomer (c1)” that can be copolymerized with the monomer (a1) and the monomer (b2) include (meth) acrylic acid ester, (meth) acrylamide, N-butoxy (meth) acrylamide, and (meth) acrylic. Nitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, and the like.

<Manufacture of photocurable (meth) acrylic resin>
Next, the manufacturing method of the said photocurable (meth) acrylic resin is demonstrated.
(A) Manufacture of Precursor In the present invention, for example, a photocuring property (meta) containing the component unit (A), the component unit (B), and the component unit (C) in the above amount (% by weight). ) In order to produce an acrylic resin, in advance, a (meth) acryloyl group-containing UV-absorbing compound (a1) represented by “RUVA-93” (manufactured by Otsuka Chemical Co., Ltd.) in the above amount;
A monomer (b2) having a radically polymerizable group ((meth) acryloyl group) and a non-radically polymerizable group (NCO) such as 2- (meth) acryloyloxyethyl isocyanate is copolymerized with another monomer (c1). . In such a copolymerization reaction, the respective components may be added in portions, and the reaction may be performed a plurality of times so that the final ratio is reached.

  This precursor formation reaction is generally performed at a temperature of about 60 to 130 ° C. for about 6 to 12 hours as a total time. Thereafter, in order to deactivate the used radical polymerization initiator, the initiator half-life is kept at high temperature for several minutes for 1 to 2 hours.

(B) Introduction of photocurable group Next, the produced copolymer (precursor), a non-radical polymerizable group (NCO) and a reactive functional group (OH group) in the precursor, and radical polymerizable properties A compound having a group ((meth) acryloyl group) (eg, 2-hydroxyethyl (meth) acrylate) is usually reacted at a temperature of about 50 to 100 ° C. for about 1 to 10 hours to obtain a desired photocurability. A (meth) acrylic resin can be produced.

  In the production of this precursor (a) and the subsequent introduction of a photocurable (meth) acryloyl group (b), a conventionally known radical polymerization initiator {example: AIBN (2,2-azobisisobutyrate) Nitrile),}, urethane reaction catalyst {example: dibutyltin dilaurate}, organic solvent (example: butyl acetate, xylene, MIBK) and the like can be used in appropriate amounts.

  In addition, in the case of the said reaction, you may use together polymerization inhibitor like p-methoxy phenol which plays the role of acryloyl group polymerization inhibition of 2HEA (refer Example: etc.). What is necessary is just to manufacture according to the above also in the case of another photocurable (meth) acrylic resin.

  In the photocurable (meth) acrylic resin thus obtained, each component unit (A), (B), (C) is present in an amount corresponding to the amount of each monomer used. This is confirmed by, for example, IR measurement, ultraviolet absorption test, photocurability test, and the like.

  Examples of the copolymer include those represented by the following structural formulas (I), (II), (III), and (IV).

また、このようにして得られた光硬化性（メタ）アクリル樹脂のＧＰＣで測定した数平均分子量（Ｍｎ）が通常、８００〜７，０００、好ましくは１，０００〜５，０００であり、重量平均分子量（Ｍｗ）が通常、３，０００〜５０，０００（５万）、好ましくは４，０００〜３，００００（３万）であり、分子量分布（Ｍｗ／Ｍｎ）が通常、２〜９、好ましくは２．５〜７であることが光硬化性樹脂組成物を基材に塗布、加工する際の適正な粘度、粘性にする点などで望ましい。

Moreover, the number average molecular weight (Mn) measured by GPC of the photocurable (meth) acrylic resin thus obtained is usually 800 to 7,000, preferably 1,000 to 5,000, and weight. The average molecular weight (Mw) is usually 3,000 to 50,000 (50,000), preferably 4,000 to 30,000 (30,000), and the molecular weight distribution (Mw / Mn) is usually 2 to 9, Preferably it is 2.5-7 from the point etc. which make the appropriate viscosity and viscosity at the time of apply | coating and processing a photocurable resin composition to a base material.

  The adjustment of Mn and Mw can be appropriately designed and changed depending on the reaction concentration, reaction temperature, amount and type of polymerization initiator, and the like. For example, if the reaction concentration is increased, the temperature is decreased, and the amount of the polymerization initiator is decreased, Mn and Mw increase.

  According to the present invention, a copolymer of a polymerizable UV-absorbing monomer such as a benzotriazole type, a benzophenone type, or a benzophenol type into which a (meth) acryloyl group is introduced and a polymerizable unsaturated monomer can be obtained. . The following photocurable resin composition such as a photocurable coating composition blended with this copolymer is different from a conventional photocurable coating composition blended with a low molecular weight ultraviolet absorber, and an ultraviolet absorber. The bleed-out problem is resolved.

[Photocurable resin composition]
The ultraviolet-absorbing photocurable resin composition according to the present invention includes at least the photocurable (meth) acrylic resin (d1) described above,
A photocurable (meth) acryloyl group-containing resin (e1);
Compared to the resin (e1), a lower molecular weight photocurable monomer or its oligomer (f1),
A photopolymerization initiator (g1);
Contains.

  When the total “(e1) + (d1) + (f1) + (g1)” of (e1) (d1) (f1) (g1) (solid content) of this composition is 100% by weight, photocurability The (meth) acrylic resin (d1) (solid content) is usually 5 to 70 parts by weight, preferably 20 to 60 parts by weight, and a photocurable (meth) acryloyl group-containing resin (e1) (solid content). Is usually 5 to 50 parts by weight, preferably 10 to 40 parts by weight, and the lower molecular weight photocurable monomer or oligomer (f1) is usually 1 as compared to the resin (e1). The photopolymerization initiator (g1) is usually used in an amount of 1 to 20 parts by weight, preferably 5 to 15 parts by weight, in an amount of -50 parts by weight, preferably 5 to 40 parts by weight.

<Photocurable (meth) acryloyl group-containing resin (e1)>
In the ultraviolet-absorbing photocurable resin composition according to the present invention, the photocurable (meth) acryloyl group-containing resin (e1) is an epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, or poly It is desirable in terms of hardness and steel wool resistance that it is formed by (co) polymerizing at least one selected from the group consisting of ether (meth) acrylates.

  In the present invention, the photocurable (meth) acryloyl group-containing resin (e1) has a number average molecular weight (Mn) measured by gel permeation chromatography of 300 to 50,000 (50,000), and It is desirable that it is at least one selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate and polyether (meth) acrylate.

  In a more preferred embodiment, the photocurable (meth) acryloyl group-containing resin (e1) has a number average molecular weight (Mn) measured by gel permeation chromatography of 1,000 to 10,000, and an epoxy (meth) acrylate. In view of hardness and steel wool resistance, at least one selected from the group consisting of urethane (meth) acrylate, polyester (meth) acrylate and polyether (meth) acrylate is desirable.

<Low molecular weight photocurable monomer or oligomer thereof (f1)>
In a more preferred embodiment of the ultraviolet-absorbing photocurable resin composition according to the present invention, the molecular weight of the photocurable monomer having a lower molecular weight than the component (e1) or its oligomer (f1) is 100 to 2000, More preferably, a photocurable monomer having a molecular weight of 150 to 1000 or an oligomer thereof is desirable in terms of hardness, steel wool resistance, and reactivity.

<Photopolymerization initiator (g1)>
In a preferred embodiment of the ultraviolet absorbing photocurable resin composition according to the present invention, it is desirable that the photopolymerization initiator (g1) contains at least an acylphosphine oxide or a thioxanthone.

  In addition to the above-mentioned components, the composition usually contains components such as those contained in UV-absorbing photocurable resin compositions (eg, polymerization inhibitors, non-reactive diluents, antifoaming agents, anti-settling agents, leveling). Agents, dispersants, heat stabilizers, matting agents, color pigments, conductive metal oxides) and the like may be included as long as they do not contradict the purpose of the present invention.

  In order to obtain such a composition, the above-mentioned components may be added and mixed at once or little by little in any order. In this case, a conventionally known method can be appropriately used. For example, mixing and stirring may be performed with a disper, a mill, a mixer, or the like.

[Weather-resistant coating, substrate, UV absorption method]
The weather-resistant film according to the present invention is formed from the ultraviolet-absorbing photocurable resin composition described in any of the above.

  The substrate according to the present invention is a substrate (coated substrate) coated with a weather-resistant film formed from the photocurable resin composition described in any one of the above. The coated film according to the present invention is characterized in that the surface of a plastic film is coated with an ultraviolet absorbing coating comprising the ultraviolet absorbing photocurable resin composition described in any of the above.

  The ultraviolet absorption method according to the present invention is characterized in that a weather-resistant film made of the ultraviolet-absorbing photocurable resin composition described in any one of the above is formed on a substrate surface.

[Example]
Hereinafter, the (meth) acryloyl group containing photocurable acrylic resin which concerns on this invention, the photocurable resin composition containing the photocurable acrylic resin, and the weather resistance film formed using the composition, The suitable aspect However, the present invention is not limited to these examples.

(BI) Measurement conditions of number average molecular weight (Mn) and weight average molecular weight (Mw) of (meth) acryloyl group-containing photocurable acrylic resin by GPC :
Apparatus: HLC-8120GPC manufactured by Tosoh Corporation
Column: Super H2000 + H4000 manufactured by Tosoh Corporation
(Each inner diameter 6mm length 15cm)
Developing solvent: THF, temperature chamber temperature: 40 ° C,
Flow rate: 0.5 ml / min, control: monodisperse polystyrene,
Detector: Refractive index change.

(B-II) Non-volatile content measurement conditions:
Heat residue after 1 g of sample was dried in a circulation dryer at 108 ° C. for 1 hour.
(B-III) Viscosity measurement conditions:
E Viscometer, measured at 25 ° C.

[Example 1]
A 300 ml reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a reflux condenser was charged with 100 parts of butyl acetate, heated to 95 ° C. in a nitrogen gas atmosphere, and 12.5 parts of MMA (methyl methacrylate). Karenz MOI (Showa Denko, 2-methacryloyloxyethyl isocyanate) 5 parts, RUVA-93 (Otsuka Chemical, 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole) 7 0.5 part and 0.75 part of AIBN (2,2′-azobisisobutyronitrile) were added and reacted at 95 ° C. for 45 minutes. Similarly, 12.5 parts of MMA, 5 parts of Karenz MOI, 7.5 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Further, this operation was repeated twice, and after the fourth addition, the reaction was carried out at 95 ° C. for 1.5 hours, and 0.14 parts of AIBN was added. Subsequently, 0.145 parts of AIBN was added twice every 45 minutes, 45 minutes later, the mixture was kept at 120 ° C. for 45 minutes and then cooled. Thus, a highly weather-resistant acrylic copolymer A-1 was obtained.

  Furthermore, 15.71 parts of 2HEA (2-hydroxyethyl acrylate), 0.0079 parts of p-methoxyphenol, 0.029 parts of dibutyltin dilaurate and 15.71 parts of butyl acetate were added and reacted at 90 ° C. for 1 hour.

  By this reaction, a photocured and highly weatherable acrylic copolymer B-1 was obtained. The obtained B-1 is a transparent solution having a nonvolatile content of 50.7% and a viscosity of 1030 mPa · s / 25 ° C., and the number average molecular weight (Mn) by gel permeation chromatography (GPC) is 3990, the weight average molecular weight (Mw) was 17890, and the dispersion ratio Mw / Mn was 4.48.

[Example 2]
A 300 ml reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube and reflux condenser was charged with 100 parts of butyl acetate, heated to 95 ° C. in a nitrogen gas atmosphere, 7.5 parts of MMA, and 10 parts of Karenz MOI. , 7.5 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Similarly, 7.5 parts of MMA, 10 parts of Karenz MOI, 7.5 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Further, this operation (ie, 7.5 parts of MMA, 10 parts of Karenz MOI, 7.5 parts of RUVA-93, 0.75 parts of AIBN, and 45 minutes reaction at 95 ° C.) was repeated twice and the fourth time was added. Thereafter, the mixture was reacted at 95 ° C. for 1.5 hours, and 0.14 parts of AIBN was added. Subsequently, 0.145 parts of AIBN was added twice every 45 minutes, 45 minutes later, the mixture was kept at 120 ° C. for 45 minutes and then cooled.

  As a result, highly weather-resistant acrylic copolymer A-2 was obtained. Further, 31.42 parts of 2HEA, 0.0157 parts of p-methoxyphenol, 0.033 parts of dibutyltin dilaurate and 31.42 parts of butyl acetate were added and reacted at 90 ° C. for 1 hour.

  As a result, a photocured high weather resistant acrylic copolymer B-2 was obtained. The obtained copolymer B-2 is a transparent solution having a non-volatile content of 49.7% and a viscosity of 840 mPa · s / 25 ° C., and has a number average molecular weight determined by gel permeation chromatography (GPC) ( Mn) was 4340, the weight average molecular weight (Mw) was 24250, and the dispersion ratio Mw / Mn was 5.59.

[Example 3]
A 300 ml reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube and reflux condenser was charged with 100 parts of butyl acetate, heated to 95 ° C. in a nitrogen gas atmosphere, and 12.5 parts of MMA, GMA (glycidyl methacrylate). ) 5 parts, 7.5 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Similarly, 12.5 parts of MMA, 5 parts of GMA, 7.5 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Further, this operation (that is, 12.5 parts of MMA, 5 parts of GMA, 7.5 parts of RUVA-93, 0.75 part of AIBN, and reaction for 45 minutes at 95 ° C.) was repeated twice, and after the fourth addition, 95 After reacting at 1.5 ° C. for 1.5 hours, 0.114 part of AIBN was added. Subsequently, 0.14 parts of AIBN was added twice every 45 minutes, and after 45 minutes, the mixture was kept at 120 ° C. for 45 minutes and then cooled. As a result, highly weather-resistant acrylic copolymer A-3 was obtained. Further, 10.14 parts of 98% acrylic acid, 0.000051 part of p-methoxyphenol, 0.112 part of BHT (2,6-di-t-butyl-4-methylphenol), 2.24 parts of dimethylbenzylamine. After reacting at 110 ° C. for 3.5 hours, n-butanol 10.14 was added. As a result, a photocured high weather resistant acrylic copolymer B-3 was obtained. The obtained copolymer B-3 is a transparent solution having a non-volatile content of 51.4% and a viscosity of 2290 mPa · s / 25 ° C., and has a number average molecular weight determined by gel permeation chromatography (GPC) ( Mn) was 1600, the weight average molecular weight (Mw) was 4830, and the dispersion ratio Mw / Mn was 3.02.

[Example 4]
A 300 ml reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a reflux condenser was charged with 100 parts of butyl acetate and heated to 95 ° C. in a nitrogen gas atmosphere, and 7.5 parts of MMA, 10 parts of GMA, RUVA 7.5 parts of -93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Similarly, 7.5 parts of MMA, 10 parts of GMA, 7.5 parts of RUVA-93, and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Further, this operation (that is, 7.5 parts of MMA, 10 parts of GMA, 7.5 parts of RUVA-93, 0.75 part of AIBN, and reaction for 45 minutes at 95 ° C.) was repeated twice and the fourth time was added. After reacting at 1.5 ° C. for 1.5 hours, 0.114 part of AIBN was added. Subsequently, 0.14 parts of AIBN was added twice every 45 minutes, and after 45 minutes, the mixture was kept at 120 ° C. for 45 minutes and then cooled.

  Thus, a highly weather-resistant acrylic copolymer A-4 was obtained. Furthermore, 20.28 parts of 98% acrylic acid, 0.0101 parts of p-methoxyphenol, 0.123 parts of BHT and 2.45 parts of dimethylbenzylamine were added and reacted at 110 ° C. for 5.5 hours, and then n-butanol 20.28. Part was added. As a result, a photocured high weather resistant acrylic copolymer B-4 was obtained.

  The obtained copolymer B-4 is a transparent solution having a non-volatile content of 50.5% and a viscosity of 2780 mPa · s / 25 ° C., and has a number average molecular weight determined by gel permeation chromatography (GPC) ( Mn) was 1460, the weight average molecular weight (Mw) was 4730, and the dispersion ratio Mw / Mn was 3.24.

[Example 5]
A 500 ml reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube and reflux condenser was charged with 100 parts of butyl acetate, heated to 95 ° C. in a nitrogen gas atmosphere, 5 parts of MMA, Karenz MOI (Showa Denko K.K. ), 2-methacryloyloxyethyl isocyanate), 5 parts, RUVA-93 (manufactured by Otsuka Chemical Co., Ltd., 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole), 15 parts, AIBN of 0 .75 parts was added and reacted at 95 ° C. for 45 minutes. Similarly, 5 parts of MMA, 5 parts of Karenz MOI, 15 parts of RUVA-93 and 0.75 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Further, this operation (that is, 5 parts of MMA, 5 parts of Karenz MOI, 15 parts of RUVA-93, 0.75 part of AIBN, and reaction for 45 minutes at 95 ° C.) was repeated twice and then the fourth time was added and then 95 ° C. After reacting for 1.5 hours, 0.114 part of AIBN was added. Subsequently, 0.145 parts of AIBN was added twice every 45 minutes, 45 minutes later, the mixture was kept at 120 ° C. for 45 minutes and then cooled.

  As a result, highly weatherable acrylic copolymer A-5 was obtained. Furthermore, 15.71 parts of 2HEA, 0.0158 parts of p-methoxyphenol and 0.029 parts of dibutyltin dilaurate were added and reacted at 90 ° C. for 1 hour. Thereafter, 16.15 parts of butyl acetate was added.

  As a result, photocured and highly weather-resistant acrylic copolymer B-5 was obtained. The obtained copolymer B-5 is a transparent solution having a non-volatile content of 51.3% and a viscosity of 730 mPa · s / 25 ° C., and has a number average molecular weight by gel permeation chromatography (GPC) ( Mn) was 3,530, the weight average molecular weight (Mw) was 14250, and the dispersion ratio Mw / Mn was 4.04.

[Example 6]
A 500 ml reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a reflux condenser was charged with 100 parts of butyl acetate and heated to 95 ° C. in a nitrogen gas atmosphere, and 3.33 parts of MMA and 3.33 parts of GMA. , 10 parts of RUVA-93 and 0.5 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Next, 3.33 parts of MMA, 3.33 parts of GMA, 10 parts of RUVA-93 and 0.5 part of AIBN were added in the same manner and reacted at 95 ° C. for 45 minutes. Further, this operation (that is, 3.33 parts of MMA, 3.33 parts of GMA, 10 parts of RUVA-93, 0.5 part of AIBN, and 45 minutes of reaction at 95 ° C.) was repeated 4 times, and after adding the sixth time, 95 After reacting at 1.5 ° C. for 1.5 hours, 0.114 part of AIBN was added. Subsequently, 0.14 parts of AIBN was added twice every 45 minutes, and after 45 minutes, the mixture was kept at 120 ° C. for 45 minutes and then cooled. As a result, highly weather-resistant acrylic copolymer A-6 was obtained.

  Furthermore, 10.14 parts of 98% acrylic acid, 0.0051 part of p-methoxyphenol, 0.11 part of BHT, and 2.2 parts of dimethylbenzylamine were added and reacted at 110 ° C. for 3.5 hours. Thereafter, 13.15 parts of n-butanol was added.

  As a result, a photocured and highly weatherable acrylic copolymer B-6 was obtained. The obtained copolymer B-6 is a transparent solution having a nonvolatile content of 64.6% and a viscosity of 1130 mPa · s / 25 ° C., and has a number average molecular weight by gel permeation chromatography (GPC) ( Mn) was 3080, the weight average molecular weight (Mw) was 12110, and the dispersion ratio Mw / Mn was 3.93.

[Example 7]
A 500 ml reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube and reflux condenser was charged with 60 parts of butyl acetate and 40 parts of n-butanol, heated to 95 ° C. in a nitrogen gas atmosphere, and MMA 3.33. Part, 3.33 parts of methacrylic acid, 10 parts of RUVA-93 and 0.5 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Next, 3.33 parts of MMA, 3.33 parts of methacrylic acid, 10 parts of RUVA-93 and 0.5 part of AIBN were added in the same manner, and the reaction was carried out at 95 ° C. for 45 minutes. Further, this operation (that is, 3.33 parts of MMA, 3.33 parts of methacrylic acid, 10 parts of RUVA-93, 0.5 part of AIBN and reaction for 45 minutes at 95 ° C.) was repeated four times and the sixth time was added. Thereafter, the mixture was reacted at 95 ° C. for 1.5 hours, and 0.14 parts of AIBN was added. Subsequently, 0.14 parts of AIBN was added twice every 45 minutes, and after 45 minutes, the mixture was kept at 115 ° C. for 45 minutes and then cooled.

  Thereby, highly weather-resistant acrylic copolymer A-7 was obtained. Further, 4HBAGE (Mitsubishi Chemical Corporation, 4-hydroxybutyl acrylate glycidyl ether) 48.84 parts, p-methoxyphenol 0.0244 parts, BHT (2,6-di-t-butyl-4-methylphenol) 0. 149 parts, 21.78 parts of butyl acetate and 1.50 parts of dimethylbenzylamine were added and reacted at 100 ° C. for 6 hours.

  As a result, a photocured high weather resistant acrylic copolymer B-7 was obtained. The obtained copolymer B-7 is a transparent solution having a nonvolatile content of 55.1% and a viscosity of 1430 mPa · s / 25 ° C., and has a number average molecular weight determined by gel permeation chromatography (GPC) ( Mn) was 3830, the weight average molecular weight (Mw) was 25090, and the dispersion ratio Mw / Mn was 6.55.

[Example 8]
A 500 ml reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube and reflux condenser was charged with 60 parts of butyl acetate and 40 parts of n-butanol, heated to 95 ° C. in a nitrogen gas atmosphere, and MMA 3.33. Part, 3.33 parts of methacrylic acid, 10 parts of RUVA-93 and 0.5 parts of AIBN were added and reacted at 95 ° C. for 45 minutes. Next, 3.33 parts of MMA, 3.33 parts of methacrylic acid, 10 parts of RUVA-93, and 0.75 parts of AIBN were added in the same manner and reacted at 95 ° C. for 45 minutes. Further, this operation (that is, 3.33 parts of MMA, 3.33 parts of methacrylic acid, 10 parts of RUVA-93, 0.75 part of AIBN and reaction for 45 minutes at 95 ° C.) was repeated four times and the sixth time was added. Thereafter, the mixture was reacted at 95 ° C. for 1.5 hours, and 0.14 parts of AIBN was added. Subsequently, 0.14 parts of AIBN was added twice every 45 minutes, and after 45 minutes, the mixture was kept at 115 ° C. for 45 minutes and then cooled.

  As a result, highly weatherable acrylic copolymer A-8 was obtained. Further, 34.68 parts of GMA, 0.0173 parts of p-methoxyphenol, 0.135 parts of BHT, 10.19 parts of butyl acetate and 1.35 parts of dimethylbenzylamine were added and reacted at 100 ° C. for 6 hours.

  As a result, a photocured high weather resistant acrylic copolymer B-8 was obtained. The resulting B-8 was a transparent solution having a non-volatile content of 54.4% and a viscosity of 2130 mPa · s / 25 ° C., and the number average molecular weight (Mn) by gel permeation chromatography (GPC) was 4090, the weight average molecular weight (Mw) was 15920, and the dispersion ratio Mw / Mn was 3.89.

  Table 1 shows the formulation compositions and quantitative ratios of Examples 1 to 8 above, the solution properties of the obtained (co) polymers, NV, viscosity, Mn, Mw, Mw / Mn, and the like.

[Examples A1 to 11, Comparative Examples A1 to 6]
In Examples A1 to 11 and Comparative Examples A1 to A6, the physical properties were evaluated using the blending components shown in Tables 2 to 4 at the blending ratios shown in the table.
The results are shown in Tables 2-4. In addition, each component used is shown below.

<Photocurable resin composition and coating film physical properties>
[1] Photocurable (meth) acrylic resin (d1) according to the present invention: B-1 to B-8 of Examples 1 to 8.

[2] Photocurable (meth) acryloyl group-containing resin (e1) according to the present invention:
Art resin UN-3320HA "urethane acrylate" (manufactured by Negami Kogyo Co., Ltd.)
Ebecryl 3700 "Epoxy acrylate" (manufactured by Daicel-Cytec),
Aronix M-7100 “Ester acrylate” (manufactured by Toagosei Co., Ltd.).

[3] Photocurable monomer (f1) used in the present invention:
“New Frontier PET-3” (Chemical name: Pentaerythritol triacrylate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).
“Aronix M-400” (manufactured by Toagosei Co., Ltd., chemical name: mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate).

[4] Photopolymerization initiator (g1):
“Irgacure 184” (chemical name: 1-hydroxy-cyclohexyl-phenyl ketone, manufactured by Ciba Specialty Chemicals).
“Bicure 55” (chemical name: methyl-phenylglyoxylate, manufactured by Akzo Nobel).
“Lucirin TPO” (chemical name: diphenyl-2,4,6-trimethylbenzoylphosphine oxide, manufactured by BASF).
“KAYACURE DETX-S” (chemical name: 2,4-diethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd.).

[5] Additive (leveling agent):
“Polyflow No. 75” (manufactured by Kyoeisha Chemical Co., Ltd.).

[Comparative example]
As shown in Table 4, materials other than the above examples were used.
[6] Ultraviolet absorbing compound:
“SANDUVOR 3212 LIQUID” (manufactured by Clariant Japan).
“RUVA-93” (manufactured by Otsuka Chemical Co., Ltd.).
“TINUVIN400” (manufactured by Ciba Specialty Chemicals).
“Zinc oxide paste 770” (manufactured by Teika).

[7] Additive (light stabilizer):
“TINUVIN123“ HALS ”(manufactured by Ciba Specialty Chemicals).
[1] to [7] were used at the component compositions and blending ratios shown in Tables 2 to 4 to obtain coating compositions according to the present invention and comparative examples.

<Formation of evaluation coating film>
On the PET film (Toyobo Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) having a film thickness of 100 μm, the above paints shown in Tables 2 to 4 were applied with a bar coater adjusted to a dry film thickness of 7 μm.

Next, one 80W / cm high-pressure mercury lamp total reflection condensing mirror type is mounted, and this coating film is applied twice at a conveyor speed of 5 m / min to an apparatus (made by IST) whose distance to the object to be irradiated is 15 cm. (Accumulated light amount: about 300 mJ / cm ² ) and cured by irradiation with ultraviolet rays to form a cured coating film.

<Evaluation methods, etc.>
Evaluation was made on 1) paint state, 2) coating state, 3) hardness, 4) adhesion, 5) weather resistance, 6) transmittance, 7) steel wool resistance, and 8) curl resistance. The results are shown in Tables 2-4.

1) Paint condition (white turbidity evaluation by compatibility)
A three-stage evaluation was made visually.
3; completely dissolved and transparent (pass).
2: White turbidity and crystal precipitation (failed) due to temperature change.
1: White turbidity and incomplete dissolution and precipitation of crystals (failed).

2) Coating state Evaluation was performed in three stages by visual observation.
3; A transparent coating film is formed (passed).
2; A coating film is formed, but some crystals are precipitated, discolored, and bleed out (failed).
1: Curing failure (failed).

3) Hardness The hardness was evaluated in three stages according to JIS K5600.
3; Hardness 2H or more (pass).
2; Hardness B to H (failed).
1: Less than B (failed).

4) The adhesive coating film was scratched on the grid (100) with a cutter, and after attaching cello tape (24 mm width manufactured by Nichiban Co., Ltd.), it was peeled off in the vertical direction to evaluate peeling.
3; 100/100 (pass).
2: 80-99 / 100 (failed).
1: 0-79 / 100 (failed).

5) Weather resistance Iwasaki Electric Co., Ltd., Eye Super UV Tester SUV-W23 was exposed for 100 hours, and Δb was measured with a color difference meter (JP7100F, manufactured by JUKI) and evaluated in three stages.
3; Transparent and good with little yellowing. There is no major change in appearance. Δb = 2 (passed).
2: Slightly yellow and transparent. Δb = 2 or more and less than 5 (failed).
1; Yellowing and film and material deteriorate. Δb = 5 or more (failed).

6) UV-cutting property The coating film was measured by U-3400 Spectrophotometer made by Hitachi, Ltd. I, and the transmittance at a wavelength of 370 nm was measured and evaluated in three stages.
3; Transmittance of 30% or less (pass).
2; Transmittance 30-50% (failed).
1; Transmittance of 50% or more (failed).

7) The steel wool resistance Gakushin type friction tester (load 500 g, steel wool # 0000) was subjected to 50 reciprocating tests, and the appearance was evaluated in three stages.
3: Almost no scratch (0 to 3 scratches) (pass).
2; Small amount of scratches (4-10 scratches) (failed).
1: A lot of scratches (10 or more scratches) (failed).

8) Curling resistance A test piece having a size of 100 mm × 100 mm was prepared, two corners were pressed, and an average value of lifting at the other corner was measured, and evaluation was performed in three stages.
3; 3 cm or less (pass).
2; 3 cm to 10 cm (failed).
1: 10 cm or more (failed).

Claims (3)

A (meth) acryloyl group-containing ultraviolet absorbing compound (a1) having an ultraviolet absorbing compound skeleton and a (meth) acryloyl group;
A compound (b2) having a (meth) acryloyl group and a non-radically polymerizable functional group;
The (meth) acryloyl group-containing UV-absorbing compound (a1) and the other monomer (c1) copolymerizable with any of the compounds (b2) are added in portions, and a radical polymerization initiator is used for the final Step (1) for forming a precursor containing the following component units (A), (B ′) and (C) by reacting and copolymerizing a plurality of times so as to obtain a predetermined amount ratio,
A step (2) of reacting the precursor with a compound (b1) having a functional group (i) and a (meth) acryloyl group capable of reacting with the non-radically polymerizable functional group (ii) in the precursor; A process for producing a photocurable (meth) acrylic resin containing the following component units (A), (B) and (C), comprising:
Component unit (A); UV-absorbing compound component unit derived from a (meth) acryloyl group-containing UV-absorbing compound (a1) having a UV-absorbing compound skeleton and a (meth) acryloyl group;
Component unit (B ′): a component derived from the compound (b2) having a (meth) acryloyl group and a non-radically polymerizable functional group (ii) and having a non-radically polymerizable functional group (ii) at the side chain terminal unit,
Component unit (C); (meth) acryloyl group-containing UV-absorbing compound (a1) that forms the component unit (A), and photopolymerizable (meth) acryloyl group that forms the component unit (B ′) A component unit derived from another monomer (c1) copolymerizable with any of the compound (b2) for deriving the compound,
Component unit (B): urethane bond or ester bond obtained by reacting the non-radically polymerizable functional group (ii) of the component unit (B ′) with the functional group (i) of the compound (b1) A photopolymerizable (meth) acryloyl group-containing compound component unit having a (meth) acryloyl group at the side chain terminal derived via the benzene.   Between the step (1) and the step (2), the radical polymerization initiator is deactivated by incubating at a high temperature at which the half-life of the radical polymerization initiator is several minutes for 45 minutes to 2 hours (1 The method for producing a photocurable (meth) acrylic resin according to claim 1, wherein:   A photocurable (meth) acrylic resin obtained by the production method according to claim 1.

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