JP7637582B2 - Active energy ray-curable (meth)acrylate polymer, its production method, and coating agent - Google Patents

Description

The present invention relates to an active energy ray-curable (meth)acrylate polymer, a method for producing the same, and a coating agent.

Conventionally, coating agents used to form hydrophobic surfaces such as active energy ray-curable and thermosetting water/oil repellents and release agents have used copolymers of long-chain (meth)acrylates such as stearyl (meth)acrylate, copolymers grafted with silicone polymers such as dimethylsiloxane, and copolymers of fluorine-based (meth)acrylates (Patent Documents 1 to 5). By forming copolymers with such specific monomers or forming graft structures, it is possible to impart properties such as water/oil repellency and release properties to the copolymers, and these are used in coating agents that exhibit antifouling and peelability, and release sheets, etc. In addition, in order to harden these copolymers, (meth)acryloyloxy groups that function as crosslinking groups are introduced into the polymers, and these are used in coating agents that are hardened by active energy rays.

Japanese Unexamined Patent Publication No. 63-202685 JP 2003-147327 A Japanese Patent Application Publication No. 55-9619 Japanese Unexamined Patent Publication No. 6-166705 JP 2010-144046 A

To improve the curing performance of active energy ray-curable polymers, it is necessary to increase the amount of crosslinking groups such as (meth)acryloyl groups introduced. However, when the amount of crosslinking groups introduced is increased, the amount of functional groups that exert releasability and water/oil repellency introduced relatively decreases, and various functionalities such as releasability tend to decrease. On the other hand, when the amount of crosslinking groups introduced is decreased in order to improve various functionalities such as releasability, curing properties may become insufficient.

The present invention has been made in consideration of the problems associated with the conventional techniques, and its object is to provide an active energy ray-curable (meth)acrylate polymer capable of preparing a coating agent with good curability, capable of forming a cured film that is excellent in water repellency, oil repellency, and releasability, while retaining properties such as adhesion, abrasion resistance, chemical resistance, and solvent resistance. Another object of the present invention is to provide a method for producing this active energy ray-curable (meth)acrylate polymer, and a coating agent using this active energy ray-curable (meth)acrylate polymer.

That is, according to the present invention, there is provided the following active energy ray-curable (meth)acrylate polymer.
[1] An active energy ray-curable (meth)acrylate polymer comprising: 10 to 60 mass% of a structural unit (i) represented by the following general formula (1); 40 to 80 mass% of a structural unit (ii) derived from at least one monomer (ii) selected from the group consisting of cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, and one-terminal (meth)acrylic-modified polysiloxane of polydimethylsiloxane having a number average molecular weight of 900 to 12,000; and 0 to 20 mass% of a structural unit (iii) derived from at least any one monomer (iii) of (meth)acrylic acid and (meth)acrylate (wherein the total of the structural units (i) to (iii) is 100 mass%), wherein at least any one of the monomers (ii) and (iii) has an acryloyloxy group in its molecular structure and has a number average molecular weight of 10,000 to 30,000.

（前記一般式（１）中、Ｒは、水素原子又は炭素数１～１８のアルキル基を示し、「Ｐｏｌｙｍｅｒ １」は、下記構成単位（ａ）３０～８５質量％、下記構成単位（ｂ）１０～４０質量％、及び下記構成単位（ｃ）０～３０質量％を含む（但し、（ａ）＋（ｂ）＋（ｃ）＝１００質量％とする）ポリマーブロックを示す。
構成単位（ａ）：グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチルメタクリレートの少なくともいずれかに由来する構成単位と、（メタ）アクリル酸とのエポキシ開環反応物（ａ１）；メタクリル酸に由来する構成単位と、グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチル（メタ）アクリレートの少なくともいずれかとのエポキシ開環反応物（ａ２）；又は２－ヒドロキシエチルメタクリレート、２－ヒドロキシプロピルメタクリレート、及び４－ヒドロキシブチルメタクリレートからなる群より選択される少なくとも一種に由来する構成単位と、（メタ）アクリロイルオキシエチルイソシアネートとの付加反応物（ａ３）
構成単位（ｂ）：炭素数６～２２のアルキル基を有するアルキルメタクリレートに由来する構成単位
構成単位（ｃ）：その他のメタクリレートに由来する構成単位）

(In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 1" represents a polymer block containing 30 to 85 mass% of the following structural unit (a), 10 to 40 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (a) + (b) + (c) = 100 mass%).
Structural unit (a): (a1) an epoxy ring-opening reaction product of a structural unit derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate with (meth)acrylic acid; (a2) an epoxy ring-opening reaction product of a structural unit derived from methacrylic acid with at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; or (a3) an addition reaction product of a structural unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate with (meth)acryloyloxyethyl isocyanate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate.

[2] The active energy ray-curable (meth)acrylate polymer according to [1] above, having an unsaturated bond equivalent of 550 to 1,350 eq/g.

According to the present invention, there is also provided a method for producing an active energy ray-curable (meth)acrylate polymer, as shown below.
[3] A method for producing an active energy ray-curable (meth)acrylate polymer according to the above [1] or [2], comprising: a step (2) of radically polymerizing a polymeric monomer represented by the following general formula (2), the monomer (ii), and the monomer (iii) to obtain a macromonomer having a number average molecular weight of 1,000 to 12,000; and a step (3) of reacting the obtained macromonomer with (meth)acrylic acid when the structural unit (d) in the following general formula (2) is structural unit (d1), reacting at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate when the structural unit (d) in the following general formula (2) is structural unit (d2), or reacting with (meth)acryloyloxyethyl isocyanate when the structural unit (d) in the following general formula (2) is structural unit (d3).

（前記一般式（２）中、Ｒは水素原子又は炭素数１～１８のアルキル基を示し、「Ｐｏｌｙｍｅｒ ２」は、下記構成単位（ｄ）、下記構成単位（ｂ）１５～４５質量％、及び下記構成単位（ｃ）０～３０質量％を含む（但し、（ｄ）＋（ｂ）＋（ｃ）＝１００質量％とする）ポリマーブロックを示す。
構成単位（ｄ）：グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチルメタクリレートの少なくともいずれかに由来する構成単位（ｄ１）；メタクリル酸に由来する構成単位（ｄ２）；又は２－ヒドロキシエチルメタクリレート、２－ヒドロキシプロピルメタクリレート、及び４－ヒドロキシブチルメタクリレートからなる群より選択される少なくとも一種に由来する構成単位（ｄ３）
構成単位（ｂ）：炭素数６～２２のアルキル基を有するアルキルメタクリレートに由来する構成単位
構成単位（ｃ）：その他のメタクリレートに由来する構成単位）

(In the above general formula (2), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 2" represents a polymer block containing the following structural unit (d), 15 to 45 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (d)+(b)+(c)=100 mass%).
Structural unit (d): A structural unit (d1) derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; a structural unit (d2) derived from methacrylic acid; or a structural unit (d3) derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate.

[4] The method for producing an active energy ray-curable (meth)acrylate polymer according to [3] above, further comprising a step (1) of polymerizing at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; methacrylic acid; or at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate, an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms, and another methacrylate in the presence of a compound represented by the following general formula (3) to obtain the polymeric monomer.

（前記一般式（３）中、Ｒは水素原子又は炭素数１～１８のアルキル基を示す）

(In the above general formula (3), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.)

Furthermore, according to the present invention, there is provided the following coating agent.
[5] An active energy ray-curable coating agent containing the active energy ray-curable (meth)acrylate polymer according to [1] or [2] above.
[6] The coating agent according to [5], further comprising an organic solvent and at least one of an active energy ray-curable monomer and oligomer having a (meth)acryloyloxy group.
[7] The coating agent according to [5] or [6] above, which is used as a release agent.
[8] The coating agent according to [5] or [6] above, which is used as a water and oil repellent.

According to the present invention, it is possible to provide an active energy ray-curable (meth)acrylate polymer that is capable of preparing a coating agent with good curability, capable of forming a cured film that has excellent water repellency, oil repellency, and releasability, while retaining properties such as adhesion, abrasion resistance, chemical resistance, and solvent resistance. In addition, according to the present invention, it is possible to provide a method for producing this active energy ray-curable (meth)acrylate polymer, and a coating agent using this active energy ray-curable (meth)acrylate polymer.

<Active energy ray curable (meth)acrylate polymer>
Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. The active energy ray curable (meth)acrylate polymer of the present invention (hereinafter also referred to as "curable polymer") contains 10 to 60 mass% of a structural unit (i) having a number average molecular weight of 1,000 to 12,000 represented by the following general formula (1), 40 to 80 mass% of a structural unit (ii) derived from at least one monomer (ii) selected from the group consisting of cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, and one-terminal (meth)acrylic-modified polysiloxane of polydimethylsiloxane having a number average molecular weight of 900 to 12,000, and 0 to 20 mass% of a structural unit (iii) derived from at least one monomer (iii) of (meth)acrylic acid and (meth)acrylate (however, the total of the structural units (i) to (iii) is 100 mass%). At least one of the monomers (ii) and (iii) is a monomer having an acryloyloxy group in its molecular structure, and the number average molecular weight of the curable polymer of the present invention is 10,000 to 30,000.

（前記一般式（１）中、Ｒは、水素原子又は炭素数１～１８のアルキル基を示し、「Ｐｏｌｙｍｅｒ １」は、下記構成単位（ａ）３０～８５質量％、下記構成単位（ｂ）１０～４０質量％、及び下記構成単位（ｃ）０～３０質量％を含む（但し、（ａ）＋（ｂ）＋（ｃ）＝１００質量％とする）ポリマーブロックを示す。
構成単位（ａ）：グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチルメタクリレートの少なくともいずれかに由来する構成単位と、（メタ）アクリル酸とのエポキシ開環反応物（ａ１）；メタクリル酸に由来する構成単位と、グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチル（メタ）アクリレートの少なくともいずれかとのエポキシ開環反応物（ａ２）；又は２－ヒドロキシエチルメタクリレート、２－ヒドロキシプロピルメタクリレート、及び４－ヒドロキシブチルメタクリレートからなる群より選択される少なくとも一種に由来する構成単位と、（メタ）アクリロイルオキシエチルイソシアネートとの付加反応物（ａ３）
構成単位（ｂ）：炭素数６～２２のアルキル基を有するアルキルメタクリレートに由来する構成単位
構成単位（ｃ）：その他のメタクリレートに由来する構成単位）

(In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 1" represents a polymer block containing 30 to 85 mass% of the following structural unit (a), 10 to 40 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (a) + (b) + (c) = 100 mass%).
Structural unit (a): (a1) an epoxy ring-opening reaction product of a structural unit derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate with (meth)acrylic acid; (a2) an epoxy ring-opening reaction product of a structural unit derived from methacrylic acid with at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; or (a3) an addition reaction product of a structural unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate with (meth)acryloyloxyethyl isocyanate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate.

The curable polymer of the present invention is a graft-type polymer having a main chain that exerts effects such as releasability, water repellency, and oil repellency, and a side chain that is bonded (grafted) to the main chain and hardens under the action of active energy rays, and is a polymer with separated functions. The polymers used in conventional coating agents have a random structure in which crosslinking groups are randomly introduced into the main chain, and are composed of short repeating units of monomer units that exert releasability, etc. and monomer units that have crosslinking groups. In contrast, the curable polymer of the present invention has a long functional monomer unit contained in the main chain, and the effects of releasability, etc. are fully exerted. In addition, since a monomer unit that is compatible with the main chain is incorporated into the graft chain, the compatibility between the main chain and the graft chain is good, and the transparency of the coating film formed can be improved. Furthermore, since the crosslinking groups are introduced into the graft chain in a dense state, the crosslinking and curing properties are good, and a coating film (cured film) with improved adhesion to the substrate can be formed.

The curable polymer of the present invention is a polymer having a highly hydrophobic main chain and a side chain (graft chain) bonded (grafted) to the main chain and having a crosslinking group introduced therein. The graft chain having a crosslinking group introduced therein is a polymer chain containing a structural unit (i) represented by the following general formula (1).

In general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. In general formula (1), "Polymer 1" represents a polymer block containing 30 to 85% by mass of the following structural unit (a), 10 to 40% by mass of the following structural unit (b), and 0 to 30% by mass of the following structural unit (c) (where (a) + (b) + (c) = 100% by mass).

Structural unit (a): (a1) an epoxy ring-opening reaction product of a structural unit derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate with (meth)acrylic acid; (a2) an epoxy ring-opening reaction product of a structural unit derived from methacrylic acid with at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; or (a3) an addition reaction product of a structural unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate with (meth)acryloyloxyethyl isocyanate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms Structural unit (c): A structural unit derived from another methacrylate

R in general formula (1) is a group derived from the compound represented by the following general formula (3) used in the manufacturing method described below.

（前記一般式（３）中、Ｒは水素原子又は炭素数１～１８のアルキル基を示す）

(In the above general formula (3), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.)

The compound represented by the general formula (3) functions as a chain transfer agent when polymerizing a methacrylate monomer. That is, when a methacrylate monomer is polymerized in the presence of the compound represented by the general formula (3), a polymerizable group can be introduced at one end of the polymer formed. When a compound represented by the general formula (3) is used as a chain transfer agent, when a monomer other than a methacrylate monomer (vinyl monomer such as styrene or acrylate) is polymerized, the polymerizable group in the general formula (3) polymerizes with these monomers, and a polymerizable group cannot be introduced at one end of the polymer formed. In contrast, when a methacrylate monomer is polymerized, the methacrylate monomer does not react with the polymerizable group in the general formula (3) due to the steric hindrance of the radical of the methacrylate monomer, and a constitutional unit represented by the general formula (1) in which a polymerizable group is introduced can be formed.

“Polymer 1” in general formula (1) contains the structural unit (a) shown below.
Structural unit (a): (a1) an epoxy ring-opening reaction product of a structural unit derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate with (meth)acrylic acid;
(a2) an epoxy ring-opening reaction product of a structural unit derived from methacrylic acid with at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; or (a3) an addition reaction product of a structural unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate with (meth)acryloyloxyethyl isocyanate.

The proportion of structural unit (a) in "Polymer 1" is 30 to 85% by mass, and preferably 35 to 80% by mass. The total of structural unit (a), structural unit (b), and structural unit (c) is 100% by mass. If the proportion of structural unit (a) is less than 30% by mass, crosslinking performance and adhesion will be insufficient. On the other hand, if the proportion of structural unit (a) is more than 85% by mass, the polymer will contain many highly polar hydroxyl groups and urethane bonds, which will reduce compatibility with the main chain.

"Polymer 1" in general formula (1) contains the structural unit (b) shown below.
Structural unit (b): a structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms

The inclusion of structural unit (b) in "Polymer 1" improves compatibility with the main chain, and the coating film (cured film) formed can be made transparent. The alkyl group having 6 to 22 carbon atoms may be linear, branched, or cyclic. Examples of alkyl methacrylates having an alkyl group having 6 to 22 carbon atoms include hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, cyclohexyl methacrylate, trimethylcyclohexyl methacrylate, t-butylcyclohexyl methacrylate, tricyclodecyl methacrylate, and isobornyl methacrylate. Among these, alkyl methacrylates having an alkyl group having 8 to 18 carbon atoms are preferred, and cetyl methacrylate, stearyl methacrylate, and behenyl methacrylate are more preferred. By using these alkyl methacrylates, the crystallization and hydrophobicity of the main chain are not inhibited, and the softening, liquefaction, and tackiness of the coating film can be reduced, while also providing effects such as release properties.

The proportion of structural unit (b) in "Polymer 1" is 10 to 40% by mass, and preferably 15 to 35% by mass. If the proportion of structural unit (b) is less than 10% by mass, compatibility with the main chain may not improve. On the other hand, if the proportion of structural unit (b) is more than 60% by mass, the glass transition point (Tg) of the side chain becomes too low, which tends to cause film softening, deterioration in performance such as releasability, and deterioration in polymerizability.

"Polymer 1" in general formula (1) may contain the structural unit (c) shown below.
Structural unit (c): Structural unit derived from other methacrylates

By introducing structural units derived from other methacrylates, it is possible to adjust the Tg of the side chain, the properties of the cured film formed (soft/hard), adhesion to the substrate, etc., and further improve the polymerization property. Other methacrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, adamantyl (meth)acrylate, adamantylmethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, methyl meth ... Examples of radical polymerizable monomers include diethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, allyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and an adduct of phthalic anhydride and 2-hydroxyethyl (meth)acrylate. Furthermore, for the purpose of improving light resistance, monomers capable of absorbing ultraviolet light, such as 2-(4-benzoxy-3-hydroxyphenoxy)ethyl methacrylate and 2-(2'-hydroxy-5-(meth)acryloyloxyethylphenyl)-2H-benzotriazole, may be used.

The proportion of structural unit (c) in "Polymer 1" is 0 to 30% by mass, and preferably 0 to 20% by mass. If the proportion of structural unit (c) exceeds 30% by mass, the proportions of structural unit (a) and structural unit (b) decrease relatively, and the effect as a side chain may become insufficient.

The curable polymer contains a structural unit (ii) derived from at least one monomer (ii) selected from the group consisting of cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, and one-terminated (meth)acrylic-modified polysiloxane of polydimethylsiloxane having a number-average molecular weight of 900 to 12,000 (hereinafter also referred to as "silicone macromonomer").

Cetyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate are highly crystalline and can impart wax-like properties to the polymer, thereby providing effects such as mold releasability and water/oil repellency. As described above, the polymerizable group of the compound represented by general formula (3) is unlikely to react with methacrylate monomers, so monomer (ii) is preferably an acrylate monomer, and cetyl acrylate, stearyl acrylate, and behenyl acrylate are particularly preferred from the viewpoint of their crystallinity.

In addition, since the silicone macromonomer has a highly hydrophobic siloxane structure, it can exhibit effects such as releasability and water/oil repellency. The silicone macromonomer usually has a (meth)acryloyl group at one end of a linear polysiloxane molecule whose main skeleton is a repeating unit of a siloxane bond (Si-O-Si). As the silicone macromonomer, polydimethylsiloxane having a (meth)acryloyloxy group at one end and an optional organic group such as a dimethylbutyloxy group at the other end is preferred.

The number average molecular weight (Mn) of the silicone macromonomer is 900 to 12,000, and preferably 2,000 to 5,000. If the Mn of the silicone macromonomer is less than 900, the water and oil repellency may be insufficient. On the other hand, if the Mn of the silicone macromonomer is more than 12,000, the polymerizability decreases and it is more likely to remain.

The proportion of the structural unit (ii) contained in the curable polymer is 40 to 80% by mass, preferably 45 to 75% by mass, when the total of the structural units (i) to (iii) is 100% by mass. If the proportion of the structural unit (ii) is less than 40% by mass, the releasability and water and oil repellency become insufficient. On the other hand, if the proportion of the structural unit (ii) is more than 80% by mass, the proportion of the structural unit (i) decreases relatively, so that the curability by active energy rays, adhesion to the substrate, abrasion resistance, etc. decrease.

The curable polymer may further contain a structural unit (iii) derived from at least one monomer (iii) of (meth)acrylic acid and (meth)acrylate. Examples of the (meth)acrylate include the same as the "other methacrylates" mentioned above. The proportion of the structural unit (ii) contained in the curable polymer is 0 to 20% by mass, preferably 0 to 15% by mass, when the total of the structural units (i) to (iii) is 100% by mass. If the proportion of the structural unit (iii) exceeds 20% by mass, the proportions of the structural units (i) and (ii) decrease relatively, and the mold releasability, water repellency, and oil repellency may be insufficient, and the crosslinking property may decrease.

The unsaturated bond present at the end of the structural unit (i) represented by general formula (1) hardly polymerizes with the methacrylate monomer, so a monomer having an acryloyloxy group in its molecular structure is used for at least one of the monomers (ii) and (iii).

The number average molecular weight (Mn) of the curable polymer is 10,000 to 30,000, preferably 11,000 to 25,000. If Mn is less than 10,000, the durability may be insufficient even after curing. On the other hand, if Mn is more than 30,000, the viscosity of the solution increases excessively, making it difficult to coat. In addition, if the solution is excessively diluted with an organic solvent to obtain a viscosity suitable for coating, it becomes difficult to form a cured film with a sufficient thickness. In this specification, the number average molecular weight (Mn) and weight average molecular weight (Mw) both refer to values calculated in terms of polystyrene as measured by gel permeation chromatography (GPC).

The unsaturated bond equivalent of the curable polymer derived from the (meth)acryloyloxy group in the general formula (1) is preferably 550 to 1,350 eq/g, and more preferably 550 to 1,300 eq/g. The unsaturated bond equivalent means the molecular weight per functional group of the (meth)acryloyloxy group in the active energy ray curable (meth)acrylate polymer. More specifically, the reciprocal of the number of moles of (meth)acryloyloxy groups per gram of resin (curable polymer) can be calculated as the molecular weight per mole of (meth)acryloyloxy groups (unsaturated bond equivalent). If the unsaturated bond equivalent exceeds 1,300 eq/g, the curability may be somewhat insufficient. On the other hand, if the unsaturated bond equivalent is less than 550 eq/g, the amount of (meth)acryloyloxy groups in the structural unit (i) increases relatively, and the compatibility with the main chain may be somewhat reduced.

<Method for producing active energy ray-curable (meth)acrylate polymer>
The curable polymer of the present invention can be produced, for example, by the method shown below. That is, the method for producing the curable polymer of the present invention is a method for producing the above-mentioned curable polymer, and includes a step (2) of radically polymerizing a polymeric monomer represented by the following general formula (2), monomer (ii), and monomer (iii) to obtain a macromonomer having a number average molecular weight of 1,000 to 12,000, and a step (3) of reacting the obtained macromonomer with (meth)acrylic acid, at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate, or (meth)acryloyloxyethyl isocyanate.

（前記一般式（２）中、Ｒは水素原子又は炭素数１～１８のアルキル基を示し、「Ｐｏｌｙｍｅｒ ２」は、下記構成単位（ｄ）、下記構成単位（ｂ）１５～４５質量％、及び下記構成単位（ｃ）０～３０質量％を含む（但し、（ｄ）＋（ｂ）＋（ｃ）＝１００質量％とする）ポリマーブロックを示す。
構成単位（ｄ）：グリシジルメタクリレート及び３，４－エポキシシクロヘキシルメチルメタクリレートの少なくともいずれかに由来する構成単位（ｄ１）；メタクリル酸に由来する構成単位（ｄ２）；又は２－ヒドロキシエチルメタクリレート、２－ヒドロキシプロピルメタクリレート、及び４－ヒドロキシブチルメタクリレートからなる群より選択される少なくとも一種に由来する構成単位（ｄ３）
構成単位（ｂ）：炭素数６～２２のアルキル基を有するアルキルメタクリレートに由来する構成単位
構成単位（ｃ）：その他のメタクリレートに由来する構成単位）

(In the above general formula (2), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 2" represents a polymer block containing the following structural unit (d), 15 to 45 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (d)+(b)+(c)=100 mass%).
Structural unit (d): A structural unit (d1) derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; a structural unit (d2) derived from methacrylic acid; or a structural unit (d3) derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate.

The method for producing a curable polymer of the present invention preferably further includes a step (1) of obtaining a polymeric monomer. In this step (1), a methacrylate monomer is polymerized in the presence of a compound represented by the following general formula (3) to obtain a polymeric monomer represented by the general formula (2). The methacrylate monomer is at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; methacrylic acid; or at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate, an alkyl methacrylate having an alkyl group with 6 to 22 carbon atoms, and another methacrylate.

（前記一般式（３）中、Ｒは水素原子又は炭素数１～１８のアルキル基を示す）

(In the above general formula (3), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.)

When a methacrylate monomer is polymerized in the presence of a compound of general formula (3), a polymer having an unsaturated bond introduced at its terminal can be formed. That is, the compound represented by general formula (3) is a component that functions as a chain transfer agent. The methacrylate monomer can be polymerized by a conventionally known solution polymerization. Specifically, when an azo-based polymerization initiator such as azobisisobutyronitrile or a peroxide-based initiator such as benzoyl peroxide is used in the presence of a compound represented by general formula (3), radicals are generated. When a methacrylate monomer is polymerized under these conditions, the generated radical reacts with the compound represented by general formula (3) to generate a tertiary carbon radical. The generated tertiary carbon radical moves to the methylene group at the α position, and the bromine bonded to the carbon at the α position is released as a radical to form an unsaturated bond terminal. The released bromine further polymerizes with the methacrylate monomer, and the radical at the polymer terminal reacts with another compound represented by general formula (3) to form an unsaturated bond terminal. When this cycle is repeated, the methacrylate radical end during polymerization cannot react with the unsaturated bond end that is formed due to steric hindrance. As a result, a polymeric monomer having an unsaturated bond end and represented by general formula (2) can be obtained.

The amount of the compound represented by general formula (3) relative to 100 parts by mass of the methacrylate monomer is preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass. If the amount of the compound represented by general formula (3) relative to 100 parts by mass of the methacrylate monomer is less than 0.5 parts by mass, the Mn of the resulting polymeric monomer tends to be large. On the other hand, if it exceeds 10 parts by mass, the Mn of the resulting polymeric monomer tends to be small.

The amount of initiator, such as an azo initiator or a peroxide initiator, is preferably 10 mol % or less based on the amount of the compound represented by general formula (3). If the amount of initiator is too large, the polymerization is likely to be completed by the initiator, and a large amount of polymer other than the desired polymeric monomer may be easily produced.

Examples of solvents used in solution polymerization include hydrocarbon solvents such as hexane, dodecane, isododecane, methylcyclohexane, and ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate, propyl acetate, and butyl acetate; ether solvents such as tetrahydrofuran, dioxolane, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; glycol solvents such as diethylene glycol monobutyl ether; glycol ester solvents such as propylene glycol monopropyl ether acetate; and amide solvents such as dimethylacetamide. Among these, it is preferable to use a solvent with low polarity, and it is preferable to use a hydrocarbon solvent, an ester solvent, or a ketone solvent.

In step (2), the polymer monomer represented by the general formula (2), the monomer (ii), and the monomer (iii) are radically polymerized to obtain a macromonomer. The specific conditions for the radical polymerization are arbitrary and are not particularly limited. In addition, the radical polymerization is preferably solution polymerization. As the solvent used in the solution polymerization, the various solvents described above can be used.

The number average molecular weight (Mn) of the macromonomer is 1,000 to 12,000, preferably 3,000 to 10,000. If the Mn of the macromonomer is less than 1,000, many reactive unsaturated bonds are introduced into the main chain, which may impair hydrophobicity. In addition, since a large amount of the compound represented by general formula (3) is used during the production of the polymeric monomer represented by general formula (2), it may be difficult to increase the polymerization rate. On the other hand, if the Mn of the macromonomer is more than 12,000, the graft chain becomes too large, which may impair hydrophobicity.

In step (3), when the structural unit (d) in the general formula (2) is the structural unit (d1), (meth)acrylic acid is reacted with the macromonomer. When the structural unit (d) in the general formula (2) is the structural unit (d2), at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate is reacted with the macromonomer. When the structural unit (d) in the general formula (2) is the structural unit (d3), (meth)acryloyloxyethyl isocyanate is reacted with the macromonomer.

When the structural unit (d) in the general formula (2) is the structural unit (d1), when (meth)acrylic acid is reacted with a macromonomer, the (meth)acrylic acid reacts with an epoxy group, the epoxy group is ring-opened, and a (meth)acryloyloxy group is introduced, forming the desired cured polymer. In the reaction, a catalyst such as an amine compound such as triethylamine; a phosphorus compound such as triphenylphosphine; a quaternary ammonium salt such as tetrabutylammonium bromide; or a quaternary phosphonium salt such as tetrabutylphosphonium chloride can be used. The amount of the catalyst is preferably 10 mol% or less based on the amount of (meth)acrylic acid. The reaction temperature is preferably 50 to 150°C, more preferably 80 to 120°C. When the epoxy group is ring-opened, a hydroxyl group is formed. The hydroxyl groups formed may be further reacted with dibasic acids such as succinic anhydride, octyl succinic anhydride, and cyclohexene dicarboxylic anhydride; monoisocyanate compounds such as stearyl isocyanate; etc. The end point of the reaction can be confirmed by using an infrared spectrophotometer to confirm the disappearance of the absorption of the epoxy groups and the generation of hydroxyl groups, or by titration to measure the acid value.

When the structural unit (d) in the general formula (2) is the structural unit (d2), by reacting at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate with a macromonomer, the epoxy group of glycidyl methacrylate or the like reacts with the carboxy group, the epoxy group is ring-opened, and (meth)acryloyloxy groups are introduced, forming the desired cured polymer. In the reaction, a catalyst such as an amine compound such as triethylamine; a phosphorus compound such as triphenylphosphine; a quaternary ammonium salt such as tetrabutylammonium bromide; or a quaternary phosphonium salt such as tetrabutylphosphonium chloride can be used. The amount of the catalyst is preferably 10 mol% or less based on the amount of (meth)acrylic acid. The reaction temperature is preferably 50 to 150°C, more preferably 80 to 120°C. When the epoxy group is ring-opened, a hydroxyl group is formed. The hydroxyl groups formed may be further reacted with dibasic acids such as succinic anhydride, octyl succinic anhydride, and cyclohexene dicarboxylic anhydride; monoisocyanate compounds such as stearyl isocyanate; etc. The end point of the reaction can be confirmed by using an infrared spectrophotometer to confirm the disappearance of the absorption of the epoxy groups and the generation of hydroxyl groups, or by titration to measure the acid value.

When the structural unit (d) in the general formula (2) is the structural unit (d3), reacting (meth)acryloyloxyethyl isocyanate with the macromonomer introduces (meth)acryloyloxy groups, forming the desired curable polymer. A catalyst such as tin dilaurate salt, bismuth salt, or zirconium salt can be used during the reaction. The reaction temperature is preferably 50 to 100°C. The end point of the reaction can be confirmed by using an infrared spectrophotometer to confirm the disappearance of the absorption of the isocyanate group or by titrating to measure the isocyanate %.

The amount of low molecular weight compounds such as (meth)acrylic acid, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and (meth)acryloyloxyethyl isocyanate reacted with the polymer monomer represented by the general formula (2) is preferably less than the amount of functional groups in the polymer monomer. If the amount of low molecular weight compounds reacted is an amount equal to or greater than the amount of functional groups in the polymer monomer, it may take a long time to react all of the low molecular weight compounds, or some low molecular weight compounds may remain. The amount of low molecular weight compounds is preferably 95 mol% or less, more preferably 90 mol% or less, relative to the amount of functional groups in the polymer monomer.

<Active energy ray curable coating agent>
The active energy ray-curable coating agent of the present invention contains the active energy ray-curable (meth)acrylate polymer described above. The coating agent of the present invention is a coating agent that can be cured by irradiation with active energy rays such as ultraviolet rays, electron beams, and radiation to form a film (cured film) that exhibits releasability and water/oil repellency.

The coating agent may further contain an organic solvent and at least one of an active energy ray curable monomer and oligomer having a (meth)acryloyloxy group. As the organic solvent, the above-mentioned organic solvents that can be used in solution polymerization can be used.

Examples of active energy ray curable monomers and oligomers having a (meth)acryloyloxy group include those similar to the above-mentioned "other methacrylates," as well as neopentyl glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, poly(n=2 or more) ethylene glycol di(meth)acrylate, polypropylene glycol (n=2 or more) di(meth)acrylate, polybutylene glycol (n=2 or more) di(meth)acrylate, vinyloxyethoxyethyl (meth)acrylate, 2,2-bis(4-(meth)acryloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxyethoxyphenyl)propane, (meth)acryloxydiethoxyphenyl)propane, trimethylolpropane diacrylate, bis(2-(meth)acryloxyethyl)-hydroxyethyl-isocyanurate, trimethylolpropane tri(meth)acrylate, tris(2-(meth)acryloxyethyl)isocyanurate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, bisphenol A diepoxy and (meth) ) epoxy poly(meth)acrylates such as epoxy di(meth)acrylate obtained by reacting acrylic acid with a trimer of 1,6-hexamethylene diisocyanate, urethane tri(meth)acrylate obtained by reacting 2-hydroxyethyl (meth)acrylate with a trimer of 1,6-hexamethylene diisocyanate, urethane di(meth)acrylate obtained by reacting isophorone diisocyanate with 2-hydroxypropyl (meth)acrylate, urethane hexa(meth)acrylate obtained by reacting isophorone diisocyanate with pentaerythritol tri(meth)acrylate, and dicyclohexyl diisocyanate with 2-hydroxyethyl (meth)acrylate. Examples of such poly(meth)acrylates include urethane di(meth)acrylates obtained by reacting a urethane reaction product of dicyclohexyl diisocyanate and poly(n=6-15)tetramethylene glycol with 2-hydroxyethyl (meth)acrylate, and other urethane poly(meth)acrylates; polyester (meth)acrylates obtained by reacting trimethylolethane with succinic acid and (meth)acrylic acid; and polyester (meth)acrylates obtained by reacting trimethylolpropane with succinic acid, ethylene glycol, and (meth)acrylic acid.

Photocurable polymers can also be appropriately incorporated. Examples of photocurable polymers include polymers such as rubber resins including poly(meth)acrylate, polyurethane, polyester, polyamide, polyimide, polyepoxy resin, polyolefin, and polybutadiene, and polymers having multiple radically polymerizable (meth)acryloyloxy groups introduced at the ends or side chains of these polymers. Furthermore, photocurable polymers having carboxy groups or the like and having alkaline developability can also be used.

In addition, a photopolymerization initiator can be contained. Examples of photopolymerization initiators include carbonyl compounds such as benzoin, benzoin monomethyl ether, benzoin isopropyl ether, acetoin, benzil, benzophenone, p-methoxybenzophenone, diethoxyacetophenone, benzil dimethyl ketal, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, methylphenyl glyoxylate, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, and the like. Examples of suitable compounds include sulfur compounds such as phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1; camphorquinone; and the like. In addition, compounds such as photosensitizers may be used in combination.

Additional additives such as leveling agents, waxes, lubricants, UV absorbers, light stabilizers, antioxidants, infrared absorbers, dyes, pigments, fillers such as silica, silane coupling agents, metal particles, antistatic agents, and conductive agents can also be included.

It is preferable to set the content of the curable polymer in the coating agent to 50% by mass or more of the film (cured film) components, since this allows the formation of a cured film that more effectively exhibits properties such as release properties and water and oil repellency. The viscosity of the coating agent may be set to any viscosity suitable for the application method (coating method). For example, when applying by flow coating or dipping, it is preferable to set the viscosity to 100 mPa·s or less.

A cured film can be formed by applying the coating agent to a substrate or an article, and then curing the coating agent by irradiating it with active energy rays. After application to a substrate, the coating agent can be heated to remove volatile components to form an uncured film. A cured film can also be formed by irradiating the uncured film with active energy rays such as ultraviolet rays, electron beams, and radiation. UV rays and electron beams can be irradiated using light sources such as high-pressure mercury lamps, metal halide lamps, xenon arcs, carbon arcs, and LED lamps. The light irradiation amount is, for example, preferably 100 to 10,000 mJ/ ^cm2 , and more preferably 300 to 5,000 mJ/ ^cm2 .

Methods for applying the coating agent include brush coating, spray coating, dip coating, flow coating, roll coating, curtain coating, spin coating, inkjet, etc.

The thickness of the cured film formed by curing the coating agent is preferably 0.1 to 50 μm, and more preferably 1 to 30 μm. By setting the thickness within this range, it is possible to obtain a cured film that is sufficiently hard, has scratch resistance, and exhibits stable adhesion over the long term, and is less susceptible to defects such as cracks.

Examples of substrates to which the coating agent is applied include polymer products such as plastic molded bodies, wood-based products, fibers, ceramics, glass, metals, composites and laminates of these materials, etc. In order to improve adhesion to the cured film to be formed, the surface of the substrate may be activated by corona treatment, plasma treatment, chemical treatment, etc.

By using the coating agent of the present invention, it is possible to impart properties such as mold releasability, water and oil repellency, peelability, antifouling property, waterproof property, fingerprint resistance, low friction, abrasion resistance, surface repellency, and resistance to adhesion of bacteria and viruses to the surface of a substrate or the like for a long period of time.
In particular, the coating agent of the present invention can be suitably used as a release agent.
In particular, when the structural unit (ii) is a structural unit derived from at least one monomer selected from the group consisting of cetyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate, it exhibits particularly good releasability and can therefore be more suitably used as a release agent.

The coating agent of the present invention can also be suitably used as a water/oil repellent. In particular, when the structural unit (ii) is a structural unit derived from a polydimethylsiloxane having a number average molecular weight of 900 to 12,000 and one end of the polysiloxane modified with (meth)acrylic, the coating agent exhibits particularly good water/oil repellency and can therefore be more suitably used as a water/oil repellent.

The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. Note that "parts" and "%" in the examples and comparative examples are based on mass unless otherwise specified.

<Production of Curable Polymer>
Example 1
A reactor equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube was charged with 300.0 parts of propylene glycol monomethyl ether acetate (PGMAc), 9.0 parts of ethyl 2-(bromomethyl)acrylate (abbreviated as EBMA), 120.0 parts of stearyl methacrylate (StMA), 90.0 parts of methyl methacrylate (MMA), and 90 parts of glycidyl methacrylate (GMA), and the mixture was heated to 65°C while bubbling nitrogen gas and stirring. 0.9 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) (trade name "V-65", Fujifilm Wako Pure Chemical Industries, Ltd.) (V-65) was added, and polymerization was carried out at 65°C for 2 hours. 0.9 parts of V-65 was further added and polymerization was carried out at 65°C for 5 hours to obtain a solution of macromonomer EM-1. A part of the reaction solution was sampled, and the solid content measured using a moisture meter was 49.5% (heating residue that reached a constant weight at 180° C.), and the polymerization rate calculated from the solid content was about 100%. The number average molecular weight (Mn) of the macromonomer measured by GPC using tetrahydrofuran (THF) as a developing solvent was 7,400, the peak top molecular weight (PT) was 10,100, and the polydispersity (PDI=weight average molecular weight (Mw)/number average molecular weight (Mn)) was 1.51.

161.6 parts of macromonomer EM-1 solution, 18.4 parts of PGMAc, 100.0 parts of butyl acetate, and 120.0 parts of stearyl acrylate (SA) were placed in a reactor equipped with a stirrer, a reflux condenser, and a thermometer, and the mixture was stirred and heated to 65°C. 3.6 parts of V-65 were added, and polymerization was carried out at 65°C for 2 hours. 1.8 parts of V-65 were further added, and polymerization was carried out at 65°C for 5 hours to form a graft copolymer. The mixture was heated to 90°C and maintained for 30 minutes to decompose the unreacted polymerization initiator, and then cooled to 40°C. A portion of the reaction solution was sampled and measured to find that the graft copolymer had an Mn of 13,700, a PT of 20,100, and a PDI of 1.88. The molecular weight shifted to the high molecular weight side, indicating that a graft copolymer had been formed.

0.5 parts of 4-methoxyphenol (MEHQ), 0.75 parts of triphenylphosphine (TPP), and 11.7 parts of acrylic acid (AA) were added to the obtained graft copolymer solution, stirred, heated to 100°C, and reacted for 4 hours to form the curable polymer RAG-1. When a part of the reaction solution was sampled and infrared (IR) absorption was measured, an absorption peak of the carbon-carbon unsaturated bond derived from AA was observed. The acid value of the curable polymer RAG-1 measured by neutralization titration using a 0.1 mol/L ethanolic potassium hydroxide solution was 1.5 mg KOH/g, and the reaction rate of AA calculated from this acid value was 94.0%. From the above, it was confirmed that AA reacted almost quantitatively with the glycidyl group in the macromonomer. The Mn of the obtained curable polymer RAG-1 was 14,200, the PT was 21,700, and the PDI was 1.85. The reaction solution was diluted with 231.4 parts of toluene to obtain a solution of curable polymer RAG-1 (solid content 34.3%).

The reaction rate of AA was calculated using the following procedure. First, the acid value of AA in the reaction solution in a state where the reaction has not progressed is calculated. Since the amount of AA in the reaction solution is "0.162/418.35 = 0.000387 mol/g", the acid value of AA is "0.000387 x 56.11 x 1000 = 21.7 mg KOH/g". The acid value of the curable polymer RAG-1 is "1.5 mg KOH/g". From the above, the reaction rate of AA can be calculated as "(21.7 - 1.5)/21.7 x 100 = 94.0%".

The method for calculating the set unsaturated bond equivalent will be explained using Example 1 as an example. 100 parts of the obtained curable polymer contains 16.5 parts of GMA·AA (Mw: 214.21), which is a reaction product of GMA and AA. Therefore, the set unsaturated bond equivalent can be calculated as "16.5/214.21/100 = 0.00077031/0.0007703 = 1,298 eq/g".

(Examples 2 to 12)
Curable polymers RAG-2 to RAG-12 were obtained in the same manner as in Example 1, except that the compositions shown in Tables 1-1, 1-2, 2, 3-1, and 3-2 were used. The meanings of the abbreviations in Tables 1-1, 1-2, 2, 3-1, and 3-2 are as follows.
ECHMA: 3,4-epoxycyclohexyl methacrylate, VA: behenyl acrylate, CA: cetyl acrylate, BA: butyl acrylate, HEMA: 2-hydroxyethyl methacrylate, TDL: tin dilaurate, AOI: 2-acryloyloxyethyl isocyanate, VMA: behenyl methacrylate, CHMA: cyclohexyl methacrylate, HPMA: 2-hydroxypropyl methacrylate, X-22-174BX: one-terminated methacrylic-modified polydimethylsiloxane (product name "X-22-174BX", manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 2,300)
X-22-174ASX: One-terminated methacrylic modified polydimethylsiloxane (product name "X-22-174ASX", manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 900)
KF2012: One-terminated methacrylic modified polydimethylsiloxane (product name "KF2012", manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 4,600)
X-22-2426: One-terminated methacrylic modified polydimethylsiloxane (product name "X-22-2426", manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 12,000)

(Comparative Example 1)
A reactor equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel was charged with 150.0 parts of PGMAc, 150.0 parts of butyl acetate, and 150.0 parts of SA, and heated to 65 ° C. In a separate vessel, 60.0 parts of MMA, 90.0 parts of GMA, and 1.5 parts of V-65 were charged and stirred to prepare a uniformly dissolved monomer solution. About half of the monomer solution was charged into the reactor, and the remainder of the monomer solution was dropped over 1.5 hours. After polymerization at 65 ° C. for 6 hours, 0.5 parts of V-65 was added, and further polymerization was performed at 65 ° C. for 2 hours to obtain a polymer solution. The mixture was heated to 90 ° C. and maintained for 30 minutes to decompose the unreacted polymerization initiator, and then cooled to 40 ° C. The solid content measured by sampling a part of the reaction solution was 49.8%, and the polymerization rate was about 100%. The resulting polymer had an Mn of 23,600, a PT of 46,100, and a PDI of 2.06.

1.0 parts of MEHQ, 3.0 parts of TDL, and 45.6 parts of AA were added to the obtained polymer solution, stirred and heated to 90°C, and reacted for 4 hours to form curable polymer H-1. A part of the reaction solution was sampled and the IR absorption was measured, and an absorption peak of the carbon-carbon unsaturated bond derived from AA was observed. The acid value of the curable polymer H-1 was 1.2 mg KOH/g, and the reaction rate of AA calculated from this acid value was 97.8%. From the above, it was confirmed that AA reacted almost quantitatively with the glycidyl group in the polymer. The Mn of the obtained curable polymer H-1 was 23,900, the PT was 47,500, and the PDI was 2.22. The reaction solution was diluted with 394.8 parts of toluene to obtain a solution of curable polymer H-1 (solid content 33.9%).

(Comparative Examples 2 and 3)
Curable polymers H-2 and H-3 were obtained in the same manner as in Comparative Example 1 except that the compositions shown in Table 4 were used.

(Comparative Examples 4 and 5)
Curable polymers H-4 and H-5 were obtained in the same manner as in Example 1 except that the compositions shown in Table 5 were used.

<Preparation of UV-curable release coating agent>
(Example 13)
20.0 parts of the curable polymer RAG-1 solution, 50.0 parts of a urethane acrylate oligomer (trade name "GD785", manufactured by DIC Corporation), 30 parts of a polyfunctional monomer (dipentaerythritol hexaacrylate (DPHA)), 3 parts of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name "Omnirad 184", manufactured by IGM Resins), and 0.8 parts of toluene were placed in a resin container. The mixture was stirred using a disperser until uniform, to obtain a UV-curable release coating agent.

(Examples 14 to 28, Comparative Examples 6 to 14)
UV-curable release coating agents were prepared in the same manner as in Example 13 above, except that the compositions shown in Tables 6-1, 6-2, and 7 (unit: parts) were used.

<Evaluation (1)>
(Production of Release Film)
The UV-curable release coating agent prepared using a bar coater (No. 6) was applied to a transparent PET film (thickness: 100 μm), and then dried for 1 minute using a dryer at 100° C. Next, the coating was cured by UV irradiation using an 80 W/cm high-pressure mercury lamp at 5 m/min and 1 pass to obtain a release film.

(Measurement of peel stress)
A 30 mm wide cellophane tape was attached to the coated surface of the obtained release film. After leaving it at room temperature (25°C) for 1 hour, it was set in a peel tester and the 180° peel strength (peel stress (N), 25°C) was measured at a tensile speed of 0.3 m/min. The release film with the cellophane tape attached to its coated surface was heated in an oven at 150°C for 1 hour and then cooled to room temperature (25°C). Then, the 180° peel strength (peel stress (N), 150°C) was measured in the same manner as above. The results are shown in Tables 6-1, 6-2, and 7.

(Evaluation of wear resistance)
A tissue paper was placed on the coated surface of the obtained release film, and a friction test was performed by rubbing it back and forth 10 times under a load of 500 g. After the friction test, the coated surface of the release film was visually observed, and the abrasion resistance was evaluated according to the following evaluation criteria. The results are shown in Tables 6-1, 6-2, and 7.
○: No change at all.
△: Slightly scratched.
x: More than half peeled off.

<Preparation of UV-curable water-repellent coating agent>
(Example 29)
50 parts of a solution of the curable polymer RAG-10, 50 parts of a urethane acrylate oligomer (GD785), 1.0 part of an ultraviolet absorber (product name "Tinuvin 400" manufactured by BASF), 3 parts of a photopolymerization initiator (Omnirad 184), and 6.6 parts of toluene were placed in a resin container. The mixture was stirred using a disperser until it was uniform, to obtain a UV-curable water-repellent coating agent.

(Examples 30 and 31, Comparative Example 15)
A UV-curable water-repellent coating agent was prepared in the same manner as in Example 29 above, except that the formulation (unit: parts) shown in Table 8 was used.

<Evaluation (2)>
(Production of film for evaluating water repellency)
The UV-curable water-repellent coating agent prepared using a bar coater (No. 6) was applied to a transparent PET film (thickness: 100 μm), and then dried for 1 minute using a dryer at 100° C. Next, the film was cured by UV irradiation using an 80 W/cm high-pressure mercury lamp at 5 m/min and 1 pass to obtain a film for evaluating water repellency.

(Evaluation of Water Repellency)
The obtained film for evaluating water repellency was attached to a stand equipped with a protractor. 50 μL of water was dropped onto the coating surface of the film using a pipette. The stand was gradually tilted, and the angle at which the water droplet slid down (initial sliding angle (°)) was measured. The results are shown in Table 8.

(Weather resistance evaluation)
Using a super xenon weather meter, the coating surface of the obtained water repellency evaluation film was irradiated with light for 500 hours. After that, the above-mentioned "evaluation of water repellency" was performed, and the angle at which the water droplets slid down (sliding angle after light irradiation (°)) was measured. The results are shown in Table 8.

The active energy ray-curable (meth)acrylate polymer of the present invention is useful as a material for coating agents for the protection and design of automobiles, buildings, exterior walls, ships, roads, solar power generators, etc.

Claims (8)

10 to 60% by mass of a structural unit (i) represented by the following general formula (1),
40 to 80% by mass of structural units (ii) derived from at least one monomer (ii) selected from the group consisting of cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, and one-terminal (meth)acrylic-modified polysiloxane of polydimethylsiloxane having a number average molecular weight of 900 to 12,000 (excluding the case where only one-terminal (meth)acrylic-modified polysiloxane of polydimethylsiloxane having a number average molecular weight of 900 to 12,000 is used) ;
and 0 to 20% by mass of structural units (iii) derived from at least one monomer (iii) of (meth)acrylic acid or (meth)acrylate (wherein the total of the structural units (i) to (iii) is 100% by mass),
At least one of the monomer (ii) and the monomer (iii) has an acryloyloxy group in its molecular structure,
An active energy ray-curable (meth)acrylate polymer having a number average molecular weight of 10,000 to 30,000.

(In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 1" represents a polymer block containing 30 to 85 mass% of the following structural unit (a), 10 to 40 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (a) + (b) + (c) = 100 mass%).
Structural unit (a): (a1) an epoxy ring-opening reaction product of a structural unit derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate with (meth)acrylic acid; (a2) an epoxy ring-opening reaction product of a structural unit derived from methacrylic acid with at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; or (a3) an addition reaction product of a structural unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate with (meth)acryloyloxyethyl isocyanate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate. The active energy ray-curable (meth)acrylate polymer according to claim 1, wherein the unsaturated bond equivalent is 550 to 1,350 eq/g. A method for producing the active energy ray-curable (meth)acrylate polymer according to claim 1 or 2, comprising the steps of:
A step (2) of radically polymerizing a polymer type monomer represented by the following general formula (2), the monomer (ii), and the monomer (iii) to obtain a macromonomer having a number average molecular weight of 1,000 to 12,000;
The obtained macromonomer is
When the structural unit (d) in the following general formula (2) is the structural unit (d1), it is reacted with (meth)acrylic acid,
When the structural unit (d) in the following general formula (2) is the structural unit (d2), at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate is reacted,
When the structural unit (d) in the following general formula (2) is the structural unit (d3), a step (3) of reacting with (meth)acryloyloxyethyl isocyanate is performed;
The present invention relates to a method for producing an active energy ray-curable (meth)acrylate polymer having the above formula:

(In the above general formula (2), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and "Polymer 2" represents a polymer block containing the following structural unit (d), 15 to 45 mass% of the following structural unit (b), and 0 to 30 mass% of the following structural unit (c) (wherein (d)+(b)+(c)=100 mass%).
Structural unit (d): A structural unit (d1) derived from at least one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; a structural unit (d2) derived from methacrylic acid; or a structural unit (d3) derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.
Structural unit (b): A structural unit derived from an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms. Structural unit (c): A structural unit derived from another methacrylate. In the presence of a compound represented by the following general formula (3),
At least one selected from the group consisting of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; methacrylic acid; or 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate;
an alkyl methacrylate having an alkyl group having 6 to 22 carbon atoms;
Other methacrylates,
The method for producing an active energy ray-curable (meth)acrylate polymer according to claim 3, further comprising the step (1) of polymerizing the above to obtain the polymeric monomer.

(In the above general formula (3), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.) An active energy ray curable coating agent containing the active energy ray curable (meth)acrylate polymer according to claim 1 or 2. An organic solvent;
The coating agent according to claim 5, further comprising at least one of an active energy ray-curable monomer and oligomer having a (meth)acryloyloxy group. The coating agent according to claim 5 or 6, which is used as a release agent. The coating agent according to claim 5 or 6, which is used as a water/oil repellent.