JP2020084085A - Active energy ray-curable composition - Google Patents

Abstract

To provide an active energy ray-curable composition capable of changing its state between a liquid and gel between high temperature and low temperature, and providing a cured article after active energy ray irradiation excellent in oil resistance.SOLUTION: There is provided an active energy ray-curable composition containing a (meth)acrylic block copolymer (I) containing a methacrylic polymer block (a1) having a partial structure (1), and an acrylic copolymer block (b) having no active energy ray-curable group, and having Mw of 20,000 or more, a (meth)acrylic copolymer (II) having Mw of 3,000 or more and smaller than Mw of the (meth)acrylic block copolymer (I), having a monomer unit same as a monomer unit constituting the polymer block (b) of 70 mol% or more and having a radical polymerizable unsaturated bond, and a compound (III) having 2 or more mercapto groups in a molecule.SELECTED DRAWING: None

Description

The present invention relates to a polymer composition having actinic radiation curability. More specifically, the present invention relates to an active energy ray-curable composition capable of changing its state between a high temperature and a low temperature in a liquid state or a gel state.

Active energy ray-curable compositions that are cured by irradiation with active energy rays such as ultraviolet rays and electron beams are known, and adhesives, adhesives, sealing materials, paints, inks, coating materials, stereolithography materials, etc. It is used for purposes.

On the other hand, a (meth)acrylic block copolymer consisting of a methacrylic polymer block and an acrylic polymer block is excellent in tackiness, moldability, weather resistance, etc. It is expected to be applied to coating materials and various molding materials.

Among the above applications, there are adhesives for fixing constituent members of optical devices such as liquid crystal displays and optical lenses and constituent devices of electronic devices such as electronic paper and batteries, and fixing them in some cases. Need to cancel. Patent Document 1 discloses that when a compatible composition in which a specific block copolymer compound and a medium are compatible with each other, the state changes between a high temperature and a low temperature into a liquid state and a gel state. It is described that the members can be easily coated below, become gel-like at a low temperature, can adhere to each other, and become liquid again when the temperature is raised again to easily release the fixation between the members.

JP, 2017-066368, A

Although the compatible composition described in Patent Document 1 has a description of a compound to which reactivity is further added and a medium having reactivity such as a (meth)acrylate-based monomer, etc., after irradiation with active energy rays The cured product of was inferior in oil resistance.

Therefore, an object of the present invention is to easily coat members at high temperatures, to form a gel at low temperatures, to bond members to each other, and to make them liquid at the high temperature again to easily release the members from each other. To provide an active energy ray-curable composition, the state of which can be changed between a high temperature and a low temperature into a liquid state or a gel state, and a cured product after irradiation with active energy rays is excellent in oil resistance. It is to be.

As a result of intensive studies to achieve the above object, the present inventors have a specific (meth)acrylic block copolymer, a specific (meth)acrylic copolymer, and a specific functional group. By using a compound, the state can be changed between liquid and gel state between high temperature and low temperature, it can be easily applied to members at high temperature, and it becomes gel state at low temperature and members can be bonded to each other. , An active energy ray-curable composition that becomes liquid when heated to a high temperature again and can easily release the fixation between members, and further, an active energy ray-curable composition in which the cured product after irradiation with active energy rays has excellent oil resistance It was found that a product can be obtained, and further studies were conducted based on the findings to complete the present invention.

The present invention relates to the following.
[1] A methacrylic polymer block (a1) having an active energy ray-curable group containing a partial structure (1) represented by the following general formula (1), and an acrylic polymer block having no active energy ray-curable group. A (meth)acrylic block copolymer (I) containing a polymer block (b) and having a weight average molecular weight of 20,000 or more, and a (meth)acrylic block copolymer having a weight average molecular weight of 3,000 or more. A monomer that is smaller than the weight average molecular weight of the polymer (I) and that constitutes the acrylic polymer block (b) having no active energy ray-curable group of the (meth)acrylic block copolymer (I). (Meth)acrylic copolymer (II) having 70% by mole or more of the same monomer unit as the unit and having a radical polymerizable unsaturated bond, and a compound having two or more mercapto groups in one molecule ( An active energy ray-curable composition containing III), which comprises the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) contained in the active energy ray-curable composition. The content of the methacrylic polymer block (a1) is 5 to 35 mass% with respect to the total mass of the active energy ray-curable composition.

(In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and W represents a saturated hydrocarbon group having 1 to 10 carbon atoms.)
[2] The (meth)acrylic copolymer (II) has a methacrylic polymer block (a2) having an active energy ray-curable group containing the partial structure (1) represented by the general formula (1). The active energy ray-curable composition according to [1], which is contained.
[3] The methacrylic polymer block (a1) and the methacrylic polymer block with respect to the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). The active energy ray-curable composition according to [2], wherein the total content of (a2) is 7 to 35% by mass.
[4] The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I) is 15 to 80% by mass, [1] to [3]. Active energy ray curable composition.
[5] The mass ratio (I)/(II) of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) is 10/90 to 50/50. The active energy ray-curable composition according to any one of [1] to [4].
[6] The mercapto group contained in the compound (III) is relative to the carbon-carbon double bond of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). The active energy ray-curable composition according to any one of [1] to [5], which is contained in an amount of 0.1 to 5.0 molar equivalents.

According to the present invention, there is provided an active energy ray-curable composition which can change its state between a high temperature and a low temperature into a liquid state or a gel state, and further, a cured product after irradiation with active energy rays has excellent oil resistance. To be done.

Hereinafter, the present invention will be described in detail.
In the present specification, "(meth)acrylic" means a generic name of "methacrylic" and "acrylic", and "(meth)allyl" means a generic name of "methallyl" and "allyl". "(Meth)acryloyl" means a generic term of "methacryloyl" and "acryloyl", and "(meth)acrylate" means a generic term of "methacrylate" and "acrylate".

The active energy ray-curable composition of the present invention comprises a methacrylic polymer block (a1) having an active energy ray-curable group containing a partial structure (1) and an acrylic polymer block having no active energy ray-curable group. A (meth)acrylic block copolymer (I) containing a polymer block (b) and having a weight average molecular weight of 20,000 or more, and a (meth)acrylic block copolymer having a weight average molecular weight of 3,000 or more. Monomers constituting the acrylic polymer block (b) having a weight average molecular weight smaller than that of the polymer (I) and having no active energy ray-curable group of the (meth)acrylic block copolymer (I). (Meth)acrylic copolymer (II) having 70% by mole or more of the same monomer unit as the unit and having a radical-polymerizable unsaturated bond, and a compound having two or more mercapto groups in one molecule ( III) is contained.

[(Meth)acrylic block copolymer (I)]
The (meth)acrylic block copolymer (I) of the present invention has a methacrylic polymer block (a1) having an active energy ray-curable group having a partial structure (1) and an active energy ray-curable group. Not contained acrylic polymer block (b).

[Active energy ray curable group]
The active energy ray-curable group containing the partial structure (1) exhibits polymerizability upon irradiation with an active energy ray. As a result, the active energy ray-curable composition of the present invention is cured to be a cured product. In addition, in this specification, an active energy ray means a light beam, an electromagnetic wave, a particle beam, and a combination thereof. Examples of light rays include far ultraviolet rays, ultraviolet rays (UV), near ultraviolet rays, visible rays, and infrared rays. Examples of electromagnetic waves include X-rays and γ rays. Particle rays include electron beams (EB) and proton rays (α). Rays), neutron rays and the like. Among these active energy rays, ultraviolet rays and electron rays are preferable, and ultraviolet rays are more preferable, from the viewpoints of curing rate, availability of an irradiation device, cost, and the like.

The partial structure (1) is represented by the following general formula (1).

In the general formula (1), R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and W represents a saturated hydrocarbon group having 1 to 10 carbon atoms.

Examples of the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a sec- group. Butyl group, t-butyl group, 2-methylbutyl group, 3-methylbutyl group, 2-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group Group, an alkyl group such as a 2-methylpentyl group, a 3-methylpentyl group and an n-decyl group; a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group; an aryl group such as a phenyl group and a naphthyl group An aralkyl group such as a benzyl group or a phenylethyl group. R ¹ is preferably a hydrogen atom or a methyl group from the viewpoint of reactivity with a mercapto group, and more preferably a hydrogen atom.

In the general formula (1), W represents a saturated hydrocarbon group having 1 to 10 carbon atoms. Here, the saturated hydrocarbon group refers to a divalent hydrocarbon group having no double bond or triple bond. W may be linear, branched or cyclic, preferably linear or branched, and more preferably linear. Examples of W include methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3- Examples thereof include a diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a cyclohexane-1,4-diyl group and the like. From the viewpoint of curability with active energy rays, W is preferably a saturated hydrocarbon group having 1 to 6 carbon atoms, more preferably a saturated hydrocarbon group having 1 to 4 carbon atoms, and particularly preferably a methanediyl group.

[Methacrylic polymer block (a1)]
The (meth)acrylic block copolymer (I) contains a methacrylic polymer block (a1) having an active energy ray-curable group containing the partial structure (1).

From the viewpoint of active energy ray curability, the ratio of the number of moles of the partial structure (1) to the number of moles of all the monomer units constituting the methacrylic polymer block (a1) is 0.01 mol% or more. It is preferably 0.05 mol% or more, more preferably 0.3 mol% or more, and particularly preferably 1.0 mol% or more. Further, it is preferably 50 mol% or less, more preferably 40 mol% or less, further preferably 30 mol% or less, further preferably 20 mol% or less, and further 10 mol% It may be less than or equal to %.

The partial structure (1) contained in the methacrylic polymer block (a1) may be at the terminal or side chain of the methacrylic polymer block, but the partial structure (1) having a preferable content is introduced. From the viewpoint of the above, it is preferable that it is at least in the side chain.

The methacrylic polymer block (a1) preferably contains a monomer unit derived from a methacrylic acid ester represented by the following general formula (2). When the methacrylic acid ester represented by the following general formula (2) is used, living anion polymerization is performed under the conditions described below, whereby the methacryloyl group is selectively polymerized, and the active energy ray curability containing the partial structure (1) is obtained. It is preferable because a methacrylic polymer block (a1) having a group can be obtained.

In the above general formula (2), the definition and description of each of R ¹ and W are the same as those in the above general formula (1), and a duplicate description will be omitted here.

Specific examples of the general formula (2) include allyl methacrylate, 3-methyl-3-butenyl methacrylate, 4-methyl-4-pentenyl methacrylate, 5-methyl-5-hexenyl methacrylate, 6-methacrylic acid. Methyl-6-heptenyl, 7-methyl-7-octenyl methacrylate, 3-ethyl-3-butenyl methacrylate, 4-ethyl-4-pentenyl methacrylate, 5-ethyl-5-hexenyl methacrylate, 6-methacrylic acid Examples thereof include ethyl-6-heptenyl and 7-ethyl-7-octenyl methacrylate. Among them, allyl methacrylate, 3-methyl-3-butenyl methacrylate and 4-methacrylate are preferred from the viewpoint of active energy ray curability. Methyl-4-pentenyl, 5-methyl-5-hexenyl methacrylate, 6-methyl-6-heptenyl methacrylate and 7-methyl-7-octenyl methacrylate are preferable, and allyl methacrylate is more preferable. These methacrylic acid esters may be used alone or in combination of two or more.

The ratio of the number of moles of the monomer unit derived from the methacrylic acid ester represented by the general formula (2) to the number of moles of all the monomer units of the methacrylic polymer block (a1) is the active energy ray curing. From the viewpoint of the property, it is preferably 0.01 mol% or more, more preferably 0.05 mol% or more, further preferably 0.3 mol% or more, and 1.0 mol% or more. It is particularly preferable that Further, it is preferably 50 mol% or less, more preferably 40 mol% or less, and may be 30 mol% or less, 20 mol% or less, and further 10 mol% or less.

The methacrylic polymer block (a1) is a monomer derived from a monofunctional methacrylic acid ester having one methacryloyl group in addition to the monomer unit derived from the methacrylic acid ester represented by the general formula (2). It is preferred to include units.

Examples of the monofunctional methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate. , Methacrylic acid ester having no functional group such as isobornyl methacrylate, dodecyl methacrylate, 2-methoxyethyl methacrylate, phenyl methacrylate and naphthyl methacrylate; 2-hydroxyethyl methacrylate, 2-hydroxybutyl methacrylate, methacrylic acid Acid trimethoxysilylpropyl, 2-aminoethyl methacrylate, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, 2-(trimethylsilyloxy)ethyl methacrylate, 3-(trimethylsilyloxy)methacrylate Propyl, glycidyl methacrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adduct of methacrylic acid, trifluoromethylmethyl methacrylate, 2-trifluoromethylethyl methacrylate, 2-perfluoroethylethyl methacrylate, 2-perfluoroethyl-2-perfluorobutylethyl methacrylate, 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethylmethyl methacrylate, 2-perfluoromethyl-2-perfluoroethyl methacrylate Examples thereof include methacrylic acid esters having a functional group such as methyl, 2-perfluorohexylethyl methacrylate, 2-perfluorodecylethyl methacrylate, and 2-perfluorohexadecylethyl methacrylate. Among these, methyl methacrylate alkyl esters having an alkyl group having 1 to 5 carbon atoms, such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and t-butyl methacrylate. Is preferred, and methyl methacrylate is more preferred. These methacrylic acid esters may be used alone or in combination of two or more.

The ratio of the number of moles of the monomer unit derived from the monofunctional methacrylic acid ester (for example, methyl methacrylate) to the number of moles of all the monomer units of the methacrylic polymer block (a1) is the active energy ray. From the viewpoint of curability, it is preferably 99.99 mol% or less, more preferably 99.95 mol% or less, further preferably 99.7 mol% or less, and 99 mol% or less. Particularly preferred is 10 mol% or more, more preferred is 30 mol% or more, and further preferred is 50 mol% or more. In addition, the ratio of the number of moles of the monomer units derived from the monofunctional methacrylic acid ester is such that when a plurality of methacrylic polymer blocks (a1) are contained in the (meth)acrylic block copolymer (I). Is preferably 99.99 mol% or less, more preferably 99.95 mol% or less, further preferably 99.7 mol% or less, and 99 mol% in each polymer block. It is particularly preferable that the amount is not more than 10 mol%, more preferably 10 mol% or more, more preferably 30 mol% or more, and further preferably 50 mol% or more.

When the methacrylic polymer block (a1) is formed from a monomer containing a monofunctional methacrylic acid ester and the methacrylic acid ester represented by the general formula (2), the methacrylic polymer block (a1) Ratio of the number of moles of monomer units derived from monofunctional methacrylic acid ester to the number of moles of all monomer units and the number of moles of monomer units derived from methacrylic acid ester represented by the above general formula (2). The total proportion of the numbers is preferably 30 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and particularly preferably 95 mol% or more. Preferably, it may be 100 mol %. Furthermore, when the methacrylic polymer block (a1) is formed from a monomer containing methyl methacrylate and a methacrylic ester represented by the general formula (2), the methacrylic polymer block (a1) The ratio of the number of moles of the monomer units derived from methyl methacrylate to the number of moles of all the monomer units and the number of moles of the monomer units derived from the methacrylic acid ester represented by the above general formula (2). The total proportion of the proportion occupied is preferably 30 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, It may be 100 mol %. Further, when the methacrylic polymer block (a1) is contained in plural in the (meth)acrylic block copolymer (I), each of the above-mentioned ratios is in the above preferable range, preferably in each polymer block. A more preferable range is one preferable aspect.

The methacrylic polymer block (a1) is not limited to the methacrylic acid ester represented by the general formula (2) and the monofunctional methacrylic acid ester having one methacryloyl group, as long as the effects of the present invention are not impaired. It may contain a monomer unit derived from a monomer.

Examples of the other monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate. , Isobornyl acrylate, dodecyl acrylate, 2-methoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, trimethoxysilylpropyl acrylate, 2-aminoethyl acrylate, N,N-acrylic acid Dimethylaminoethyl, N,N-diethylaminoethyl acrylate, phenyl acrylate, naphthyl acrylate, 2-(trimethylsilyloxy)ethyl acrylate, 3-(trimethylsilyloxy)propyl acrylate, glycidyl acrylate, γ-(acryloyloxy) Propyl)trimethoxysilane, acrylic acid ethylene oxide adduct, trifluoromethylmethyl acrylate, 2-trifluoromethylethyl acrylate, 2-perfluoroethylethyl acrylate, 2-perfluoroethyl-2-peracrylate Fluorobutylethyl, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethylmethyl acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl acrylate, 2-perfluorohexylethyl acrylate, Acrylic esters such as 2-perfluorodecylethyl acrylate and 2-perfluorohexadecylethyl acrylate; α-alkoxyacrylic esters such as methyl α-methoxyacrylate and methyl α-ethoxyacrylate; methyl crotonic acid, Crotonic acid esters such as ethyl crotonic acid; 3-alkoxyacrylic acid esters such as 3-methoxyacrylic acid ester; N-isopropyl(meth)acrylamide, Nt-butyl(meth)acrylamide, N,N-dimethyl(meth) (Meth)acrylamides such as acrylamide, N,N-diethyl (meth)acrylamide; methyl 2-phenylacrylate, ethyl 2-phenylacrylate, n-butyl 2-bromoacrylate, methyl 2-bromomethylacrylate, 2 -Ethyl bromomethyl acrylate, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, ethyl isopropenyl ketone and the like can be mentioned.

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

From the viewpoint of curability, the ratio of the number of moles of the monomer units derived from the other monomer to the number of moles of all the monomer units constituting the methacrylic polymer block (a1) is 10 mol%. It is preferably below, and more preferably below 5 mol %. Further, the ratio of the number of moles of the monomer units derived from the other monomer to the number of moles of all the monomer units constituting the methacrylic polymer block (a1) is such that In the case where a plurality of () are contained in the (meth)acrylic block copolymer (I), it is desirable that the content in each polymer block is preferably 10 mol% or less, more preferably 5 mol% or less. Is.

The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I) is preferably 80% by mass or less, more preferably 70% by mass or less, and 15 It is preferably at least mass%, more preferably at least 30 mass%. When the content is more than the above lower limit, gelation tends to occur at low temperature, and when it is less than the above upper limit, viscosity reduction at high temperature tends to be excellent.

The glass transition temperature (Tg) of the methacrylic polymer block (a1) is preferably 90°C or higher, more preferably 95°C or higher, and further preferably 100°C or higher. Further, it is preferably 160° C. or lower, and more preferably 150° C. or lower. The Tg of the methacrylic polymer block (a1) can be controlled by the type of monomer forming the methacrylic polymer block (a1), the polymerization method, and the like. When the Tg of the methacrylic polymer block (a1) is in this range, the handleability and heat resistance of the obtained (meth)acrylic block copolymer (I) are improved. The Tg in the present specification means a polymer found in a curve obtained by DSC measurement of a polymer block or a (meth)acrylic block copolymer (I) under a temperature rising condition of 10° C./min. It is the extrapolation start temperature (Tgi) of the transition region of the block.

The weight average molecular weight of the methacrylic polymer block (a1) is 500 or more and 40,000 or less from the viewpoint of handleability, fluidity, mechanical properties, etc. of the (meth)acrylic block copolymer (I) to be obtained. It is preferably 1,000 or more and 30,000 or less. When a plurality of methacrylic polymer blocks (a1) are contained in the (meth)acrylic block copolymer (I), the weight average molecular weight of each polymer block should be in the above-mentioned preferable range, preferably in the more preferable range. Is a preferred embodiment. In the present specification, the number average molecular weight (Mn), the weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) are based on standard polystyrene conversion values obtained by gel permeation chromatography (GPC) measurement, and their values. It is a calculated value.

[Acrylic polymer block (b)]
The (meth)acrylic block copolymer (I) contains an acrylic polymer block (b) having no active energy ray-curable group.

In the present specification, the active energy ray-curable group means a functional group exhibiting polymerizability upon irradiation with the active energy ray. Examples of the active energy ray-curable group include (meth)acryloyl group (may be (meth)acryloyloxy group), vinyl group, (meth)allyl group, vinyloxy group, 1,3-dienyl group, and styryl. Functional group having an ethylenic double bond such as a group (in particular, an ethylenic double bond represented by the general formula CH ₂ ═CR— (wherein R is an alkyl group or a hydrogen atom)); epoxy group, oxetanyl group, thiol Group, maleimide group and the like.

The acrylic polymer block (b) preferably contains a monomer unit derived from an acrylate ester.

Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and acrylic. Isobornyl acid, lauryl acrylate, dodecyl acrylate, trimethoxysilylpropyl acrylate, N,N-dimethylaminoethyl acrylate, N,N-diethylaminoethyl acrylate, 2-methoxyethyl acrylate, phenyl acrylate, acrylic acid Naphthyl, 2-(trimethylsilyloxy)ethyl acrylate, 3-(trimethylsilyloxy)propyl acrylate, tetrahydrofurfuryl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, phenoxyethyl acrylate, acrylic acid 2-(2-ethoxyethoxy)ethyl, methoxytriethylene glycol acrylate, acrylic acid (2-methyl-2-ethyl-1,3-dioxolan-4-yl), acrylic acid (3-ethyloxetan-3-yl) ) And the like. From the viewpoint of lowering the viscosity when it becomes liquid at high temperature, among these, n-butyl acrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, Methoxytriethylene glycol acrylate and 2-methoxyethyl acrylate are preferable, and from the viewpoint of imparting oil resistance to the cured product after irradiating the active energy ray-curable composition of the present invention with active energy rays, hydrophilicity is Higher tetrahydrofurfuryl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, methoxytriethylene glycol acrylate, and 2-methoxyethyl acrylate are more preferable, and 2-methoxyethyl acrylate is even more preferable. These acrylic acid esters may be used alone or in combination of two or more.

As the solubility parameter (SP value) of the acrylic ester, the compatibility with the (meth)acrylic copolymer (II) and the active energy ray-curable composition of the present invention after irradiation with active energy rays From the viewpoint of the oil resistance of the cured product, it is preferably 8.0 or more, more preferably 8.5 or more, still more preferably 9.0 or more. Moreover, 13 or less is preferable, 12.5 or less is more preferable, and 12 or less is further preferable. In addition, the solubility parameter in this specification is a value calculated by the estimation method of the Fedors method, and the solubility parameter of 2-methoxyethyl acrylate used in the examples is 9.5.

From the viewpoint of viscosity, the content of the monomer unit derived from the acrylate ester is preferably 30 mol% or more with respect to the number of moles of all the monomer units of the acrylic polymer block (b), It is more preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, and may be 100 mol%. When the (meth)acrylic block copolymer (I) contains a plurality of acrylic polymer blocks (b), the content of the monomer unit derived from the above-mentioned acrylate ester is In each block, the content is preferably 90 mol% or more, more preferably 95 mol% or more, and may be 100 mol%.

The acrylic polymer block (b) may contain a monomer unit derived from another monomer in addition to the above-mentioned acrylic acid ester, as long as the effect of the present invention is not impaired.

Examples of the other monomer include methacrylic acid esters described above; α-alkoxyacrylic acid esters such as methyl α-methoxyacrylate and methyl α-ethoxyacrylate; crotonic acid such as methyl crotonic acid and ethyl crotonic acid. Ester; 3-alkoxyacrylic ester such as 3-methoxyacrylic ester; acrylamide such as N-isopropylacrylamide, Nt-butylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide; N-isopropylmethacryl Methacrylamides such as amides, N-t-butylmethacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide; methyl 2-phenylacrylate, ethyl 2-phenylacrylate, 2-bromoacrylic acid n. -Butyl, methyl 2-bromomethyl acrylate, ethyl 2-bromomethyl acrylate, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, ethyl isopropenyl ketone and the like.

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

The ratio of the number of moles of the monomer unit derived from the other monomer to the number of moles of all the monomer units constituting the acrylic polymer block (b) is preferably 10 mol% or less. It is more preferably 5 mol% or less. Further, the ratio of the number of moles of the monomer units derived from the other monomer to the number of moles of all the monomer units constituting the acrylic polymer block (b) is such that the acrylic polymer block (b In the case where a plurality of () are contained in the (meth)acrylic block copolymer (I), it is desirable that the content of each of the polymer blocks is preferably 10 mol% or less, more preferably 5 mol% or less. Is.

The content of the acrylic polymer block (b) in the (meth)acrylic block copolymer (I) is preferably 20% by mass or more, more preferably 30% by mass or more, and 85 It is preferably at most% by mass, more preferably at most 70% by mass. When the content is at least the above lower limit, it tends to be excellent in lowering the viscosity when it becomes liquid at high temperature, and when it is at most the above upper limit, it tends to be gel at low temperature.

The glass transition temperature (Tg) of the acrylic polymer block (b) is preferably 0° C. or lower, more preferably −10° C. or lower, and further preferably −20° C. or lower. The Tg of the acrylic polymer block (b) can be controlled by the type of monomer forming the acrylic polymer block (b), the polymerization method, and the like. When the Tg of the acrylic polymer block (b) is within this range, it is preferable from the viewpoint of lowering the viscosity when it becomes liquid at high temperature.

The weight average molecular weight of the acrylic polymer block (b) is 5,000 or more and 300,000 or less from the viewpoint of handleability, fluidity, mechanical properties and the like of the obtained (meth)acrylic block copolymer (I). Is preferable, and 10,000 or more and 200,000 or less is more preferable.

The weight average molecular weight of the (meth)acrylic block copolymer (I) used in the present invention is 20,000 or more, and preferably 30,000 or more in order to form a gel at low temperature. Further, it is preferably 400,000 or less, and more preferably 300,000 or less. When the weight average molecular weight of the (meth)acrylic block copolymer (I) is at most the above upper limit, it tends to have excellent fluidity when it becomes liquid at high temperature.

The molecular weight distribution of the (meth)acrylic block copolymer (I), that is, the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.00 or less, and 1.01 to The range of 1.80 is more preferable, and the range of 1.01 to 1.50 is further preferable.

The (meth)acrylic block copolymer (I) is a block copolymer having at least one methacrylic polymer block (a1) and at least one acrylic polymer block (b). The number of united blocks and the order of bonding are not particularly limited, but the methacrylic polymer block (a1) has at least one terminal of the (meth)acrylic block copolymer (I) from the viewpoint of active energy ray curability. From the viewpoint of ease of production of the (meth)acrylic block copolymer (I), a linear polymer is more preferable, and one methacrylic polymer block (a1) is preferable. And a diblock copolymer in which one acrylic polymer block (b) is bonded, or one methacrylic polymer block (a1) is bonded to both ends of one acrylic polymer block (b), respectively. The above-mentioned triblock copolymer is more preferable.

The method for producing the (meth)acrylic block copolymer (I) is not particularly limited, but for example, anionic polymerization method or radical polymerization method is preferable. From the viewpoint of controlling polymerization, living polymerization methods such as living anion polymerization method and living radical polymerization method are more preferable, and living anion polymerization method is further preferable.

As the living radical polymerization method, a polymerization method using a chain transfer agent such as polysulfide, a polymerization method using a cobalt porphyrin complex, a polymerization method using a nitroxide (see International Publication No. 2004/014926 etc.), organic tellurium compounds, etc. Polymerization method using a periodic hetero element compound (see Japanese Patent No. 3839829), reversible addition elimination chain transfer polymerization method (RAFT) (see Japanese Patent No. 3639859), atom transfer radical polymerization method (ATRP) (See Japanese Patent No. 3040172 and International Publication No. 2004/013192). Among these living radical polymerization methods, the atom transfer radical polymerization method is preferable, with an organic halide or a sulfonyl halide compound as an initiator, and at least one selected from the group consisting of Fe, Ru, Ni and Cu as a central metal. More preferred is an atom transfer radical polymerization method using a metal complex as a catalyst.

Examples of the living anion polymerization method include a method of living polymerization using an organic rare earth metal complex as a polymerization initiator (see JP-A-6-93060, etc.), and an alkali metal or alkaline earth metal of an organic alkali metal compound as a polymerization initiator. Living anion polymerization in the presence of a salt such as a salt (see JP-A-5-507737), and living anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound. Methods (see JP-A No. 11-335432, WO 2013/141105, etc.) and the like. Among these living anionic polymerization methods, from the standpoint that the (meth)acrylic block copolymer (I) can be directly and efficiently polymerized, living using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound. The method of anionic polymerization is preferable, and the method of living anion polymerization using an organic lithium compound as a polymerization initiator in the presence of an organic aluminum compound and a Lewis base is more preferable.

The amount of the organolithium compound used can be determined by the ratio with the amount of the monomer used, depending on the number average molecular weight of the target (meth)acrylic block copolymer (I).

Examples of the organoaluminum compound include organoaluminum compounds represented by the following general formula (A-1) or (A-2).
^{AlR 2 (R 3) (R} 4) (A-1)
(In the formula, R ² represents a monovalent saturated hydrocarbon group, a monovalent aromatic hydrocarbon group, an alkoxy group, an aryloxy group or an N,N-disubstituted amino group, and R ³ and R ⁴ are each independently. Represents an aryloxy group, or R ³ and R ⁴ are bonded to each other to form an arylenedioxy group.)
AlR ⁵ (R ⁶ ) (R ⁷ ) (A-2)
(In the formula, R ⁵ represents an aryloxy group, and R ⁶ and R ⁷ are each independently a monovalent saturated hydrocarbon group, a monovalent aromatic hydrocarbon group, an alkoxy group, or an N,N-disubstituted amino group. Represents a group.)
In the general formulas (A-1) and (A-2), examples of the aryloxy group represented by R ² , R ³ , R ⁴ and R ⁵ each independently include, for example, a phenoxy group, a 2-methylphenoxy group, and a 4-methylphenoxy group. -Methylphenoxy group, 2,6-dimethylphenoxy group, 2,4-di-t-butylphenoxy group, 2,6-di-t-butylphenoxy group, 2,6-di-t-butyl-4-methyl Phenoxy group, 2,6-di-t-butyl-4-ethylphenoxy group, 2,6-diphenylphenoxy group, 1-naphthoxy group, 2-naphthoxy group, 9-phenanthryloxy group, 1-pyrenyloxy group, A 7-methoxy-2-naphthoxy group and the like can be mentioned.

In the general formula (A-1), examples of the arylenedioxy group formed by combining R ³ and R ⁴ with each other include 2,2′-biphenol, 2,2′-methylenebisphenol, 2,2′. -Methylenebis(4-methyl-6-t-butylphenol), (R)-(+)-1,1'-bi-2-naphthol, (S)-(-)-1,1'-bi-2- A functional group obtained by removing a hydrogen atom from the two phenolic hydroxyl groups in a compound having two phenolic hydroxyl groups such as naphthol can be mentioned.
Incidentally, one or more hydrogen atoms contained in the above aryloxy group and arylenedioxy group may be substituted with a substituent, and as the substituent, for example, a methoxy group, an ethoxy group, an isopropoxy group, Examples thereof include alkoxy groups such as t-butoxy group; halogen atoms such as chlorine atom and bromine atom.

In the general formulas (A-1) and (A-2), examples of the monovalent saturated hydrocarbon group represented by R ² , R ⁶ and R ⁷ each independently include, for example, a methyl group, an ethyl group and n-propyl. Group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, 2-methylbutyl group, 3-methylbutyl group, n-octyl group, 2-ethylhexyl group, and other alkyl groups; cyclohexyl group, etc. Examples of the monovalent aromatic hydrocarbon group include an aryl group such as a phenyl group; an aralkyl group such as a benzyl group; and an alkoxy group such as a methoxy group and an ethoxy group. , An isopropoxy group, a t-butoxy group, and the like. Examples of the N,N-disubstituted amino group include a dialkylamino group such as a dimethylamino group, a diethylamino group, and a diisopropylamino group; and a bis(trimethylsilyl)amino group. Can be mentioned. One or more hydrogen atoms contained in the above-mentioned monovalent saturated hydrocarbon group, monovalent aromatic hydrocarbon group, alkoxy group and N,N-disubstituted amino group may be substituted with a substituent. Examples of the substituent include an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group and a t-butoxy group; a halogen atom such as a chlorine atom and a bromine atom.

Examples of the organoaluminum compound (A-1) include ethylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum, ethylbis(2,6-di-t-butylphenoxy)aluminum, ethyl[2 ,2'-Methylenebis(4-methyl-6-t-butylphenoxy)]aluminum, isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum, isobutylbis(2,6-di-t). -Butylphenoxy)aluminum, isobutyl[2,2'-methylenebis(4-methyl-6-t-butylphenoxy)]aluminum, n-octylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum, n-octylbis(2,6-di-t-butylphenoxy)aluminum, n-octyl[2,2'-methylenebis(4-methyl-6-t-butylphenoxy)]aluminum, methoxybis(2,6-di- t-butyl-4-methylphenoxy)aluminum, methoxybis(2,6-di-t-butylphenoxy)aluminum, methoxy[2,2′-methylenebis(4-methyl-6-t-butylphenoxy)]aluminum, ethoxybis (2,6-di-t-butyl-4-methylphenoxy)aluminum, ethoxybis(2,6-di-t-butylphenoxy)aluminum, ethoxy[2,2'-methylenebis(4-methyl-6-t-). Butylphenoxy)] aluminum, isopropoxybis(2,6-di-t-butyl-4-methylphenoxy)aluminum, isopropoxybis(2,6-di-t-butylphenoxy)aluminum, isopropoxy[2,2 '-Methylenebis(4-methyl-6-t-butylphenoxy)] aluminum, t-butoxybis(2,6-di-t-butyl-4-methylphenoxy)aluminum, t-butoxybis(2,6-di-t). -Butylphenoxy)aluminum, t-butoxy[2,2'-methylenebis(4-methyl-6-t-butylphenoxy)]aluminum, tris(2,6-di-t-butyl-4-methylphenoxy)aluminum, Examples include tris(2,6-diphenylphenoxy)aluminum and the like. Among them, isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum and isobutylbis(2,6) are preferred from the viewpoints of polymerization initiation efficiency, living property of polymerization terminal anion, availability and easy handling. -Di-t-butylphenoxy)aluminum and isobutyl[2,2'-methylenebis(4-methyl-6-t-butylphenoxy)]aluminum are preferred.

Examples of the organoaluminum compound (A-2) include diethyl (2,6-di-t-butyl-4-methylphenoxy) aluminum, diethyl (2,6-di-t-butylphenoxy) aluminum, and diisobutyl (2 ,6-Di-t-butyl-4-methylphenoxy)aluminum, diisobutyl(2,6-di-t-butylphenoxy)aluminum, di-n-octyl(2,6-di-t-butyl-4-methyl) Phenoxy)aluminum, di-n-octyl (2,6-di-t-butylphenoxy)aluminum and the like. These organoaluminum compounds may be used alone or in combination of two or more.

The amount of the organoaluminum compound to be used can be appropriately selected depending on the kind of the solvent, various other polymerization conditions and the like, but is usually 1.0 to 10 with respect to 1 mol of the organolithium compound from the viewpoint of the polymerization rate. It is preferably used in the range of 0.0 mol, more preferably in the range of 1.1 to 5.0 mol, and further preferably in the range of 1.2 to 4.0 mol. If the amount of the organoaluminum compound used exceeds 10.0 mol with respect to 1 mol of the organolithium compound, the economy tends to be disadvantageous, and if it is less than 1.0 mol, the polymerization initiation efficiency tends to decrease.

Examples of the Lewis base include compounds having an ether bond and/or a tertiary amine structure in the molecule.

Examples of the compound having an ether bond in the molecule used as the Lewis base include ether. As the ether, a cyclic ether having two or more ether bonds in the molecule or an acyclic ether having one or more ether bonds in the molecule from the viewpoint of high polymerization initiation efficiency and living property of the polymerization terminal anion. Is preferred. Examples of the cyclic ether having two or more ether bonds in the molecule include crown ethers such as 12-crown-4, 15-crown-5 and 18-crown-6. Examples of the non-cyclic ether having one or more ether bonds in the molecule include non-cyclic monoethers such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether and anisole; 1,2-dimethoxyethane, 1,2-diethoxy. Ethane, 1,2-diisopropoxyethane, 1,2-dibutoxyethane, 1,2-diphenoxyethane, 1,2-dimethoxypropane, 1,2-diethoxypropane, 1,2-diisopropoxypropane 1,2-dibutoxypropane, 1,2-diphenoxypropane, 1,3-dimethoxypropane, 1,3-diethoxypropane, 1,3-diisopropoxypropane, 1,3-dibutoxypropane, 1 ,3-Diphenoxypropane, 1,4-dimethoxybutane, 1,4-diethoxybutane, 1,4-diisopropoxybutane, 1,4-dibutoxybutane, 1,4-diphenoxybutane, etc. Diether; diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dibutylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, dibutylene glycol diethyl ether, triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tributylene glycol dimethyl ether, triethylene glycol diethyl Acyclic such as ether, tripropylene glycol diethyl ether, tributylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, tetrabutylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetrapropylene glycol diethyl ether, tetrabutylene glycol diethyl ether A polyether is mentioned. Among these, acyclic ethers having 1 to 2 ether bonds in the molecule are preferable, and diethyl ether or 1,2-dimethoxyethane is more preferable, from the viewpoints of suppressing side reactions, availability, and the like.

Examples of the compound having a tertiary amine structure in the molecule used as the Lewis base include tertiary polyamines. The tertiary polyamine means a compound having two or more tertiary amine structures in the molecule. Examples of the tertiary polyamine include N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetraethylethylenediamine, N,N,N′,N″,N″-pentamethyl. Chain polyamines such as diethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, tris[2-(dimethylamino)ethyl]amine; 1,3,5-trimethylhexahydro-1, 3,5-triazine, 1,4,7-trimethyl-1,4,7-triazacyclononane, 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16 -Non-aromatic heterocyclic compounds such as hexaazacyclooctadecane; aromatic heterocyclic compounds such as 2,2'-bipyridyl and 2,2':6',2"-terpyridine.

Further, a compound having at least one ether bond and at least one tertiary amine structure in the molecule may be used as the Lewis base. Examples of such a compound include tris[2-(2-methoxyethoxy)ethyl]amine.

These Lewis bases may be used alone or in combination of two or more.

The amount of the Lewis base used is preferably 0.3 to 5.0 mol, and 0.5 to 5.0 mol, based on 1 mol of the organolithium compound, from the viewpoints of polymerization initiation efficiency, stability of the polymerization terminal anion, and the like. It is more preferably in the range of 3.0 mol, and further preferably in the range of 1.0 to 2.0 mol. If the amount of the Lewis base used is more than 5.0 mols per mol of the organolithium compound, the economy tends to be disadvantageous, and if less than 0.3 mols, the polymerization initiation efficiency tends to decrease.

The amount of Lewis base used is preferably in the range of 0.2 to 1.2 mol, and more preferably in the range of 0.3 to 1.0 mol, per 1 mol of the organoaluminum compound. ..

The living anionic polymerization is preferably carried out in the presence of an organic solvent from the viewpoint of temperature control and homogenization of the system to smoothly proceed the polymerization. As the organic solvent, hydrocarbons such as toluene, xylene, cyclohexane, and methylcyclohexane; chloroform, chloride, etc., from the viewpoints of safety, separability from water in washing the reaction solution after polymerization, ease of recovery and reuse, etc. Halogenated hydrocarbons such as methylene and carbon tetrachloride; esters such as dimethyl phthalate are preferred. These organic solvents may be used alone or in combination of two or more. In addition, it is preferable that the organic solvent is subjected to a drying treatment and degassed in the presence of an inert gas in advance from the viewpoint of smoothly proceeding the polymerization.

Further, in the above living anionic polymerization, other additives may be present in the reaction system, if necessary. Examples of the other additives include inorganic salts such as lithium chloride; metal alkoxides such as lithium methoxyethoxyethoxide and potassium t-butoxide; tetraethylammonium chloride and tetraethylphosphonium bromide.

The living anionic polymerization is preferably carried out at -30 to 25°C. If the temperature is lower than -30°C, the polymerization rate tends to be low and the productivity tends to be low. On the other hand, if the temperature is higher than 25°C, it tends to be difficult to polymerize the monomer containing the methacrylic acid ester represented by the general formula (2) with good living property.

The living anionic polymerization is preferably carried out in an atmosphere of an inert gas such as nitrogen, argon or helium. Furthermore, it is preferable to carry out under sufficient stirring conditions so that the reaction system becomes uniform.

In the living anionic polymerization, as a method of adding the organolithium compound, the organoaluminum compound, the Lewis base and the monomer to the reaction system, the Lewis base is contacted with the organoaluminum compound before the contact with the organolithium compound. It is preferable to add. Further, the organoaluminum compound may be added to the reaction system before the monomer, or may be added simultaneously. When the organoaluminum compound is added to the reaction system at the same time as the monomer, the organoaluminum compound may be separately added with the monomer and then added.

The living anionic polymerization can be stopped by adding a polymerization terminator such as a protic compound such as methanol; a methanol solution of acetic acid or hydrochloric acid; an aqueous solution of acetic acid or hydrochloric acid to the reaction solution. Usually, the amount of the polymerization terminator used is preferably in the range of 1 to 1,000 mol per 1 mol of the organolithium compound used.

As a method for separating and obtaining the (meth)acrylic block copolymer (I) from the reaction liquid after the termination of living anionic polymerization, a known method can be adopted. For example, the reaction solution is poured into a poor solvent for the (meth)acrylic block copolymer (I) to cause precipitation, and the organic solvent is distilled off from the reaction solution to obtain the (meth)acrylic block copolymer (I). A method of acquiring the information can be given.

When the metal component derived from the organolithium compound and the organoaluminum compound remains in the (meth)acrylic block copolymer (I) obtained separately, the (meth)acrylic block copolymer (I) May cause deterioration in physical properties, poor transparency, and the like. Therefore, it is preferable to remove the metal components derived from the organolithium compound and the organoaluminum compound after the termination of the anionic polymerization. As a method for removing the metal component, a cleaning treatment using an acidic aqueous solution, an adsorption treatment using an adsorbent such as an ion exchange resin, Celite, or activated carbon is effective. Here, as the acidic aqueous solution, for example, hydrochloric acid, sulfuric acid aqueous solution, nitric acid aqueous solution, acetic acid aqueous solution, propionic acid aqueous solution, citric acid aqueous solution, or the like can be used.

In the production of the (meth)acrylic block copolymer (I), the method for introducing the partial structure (1) is to polymerize a monomer containing a methacrylic acid ester represented by the general formula (2). In addition to the method for forming the methacrylic polymer block (a1) by using, after forming a polymer block containing a partial structure (hereinafter, referred to as “precursor structure”) to be a precursor of the partial structure (1), A method of converting the precursor structure into the partial structure (1) is also included. The polymer block containing a precursor structure is obtained by polymerizing a monomer containing a polymerizable functional group and a compound containing a precursor structure (hereinafter referred to as “polymerizable precursor”). Examples of the polymerizable functional group include a styryl group, a 1,3-dienyl group, a vinyloxy group and a (meth)acryloyl group, and a (meth)acryloyl group is preferable. As the precursor structure, a hydroxyl group, a hydroxyl group protected by a protecting group (silyloxy group, acyloxy group, alkoxy group, etc.), an amino group, an amino group protected by a protecting group, a thiol group, a thiol group protected by a protecting group , Isocyanate groups and the like.

The polymer block containing a hydroxyl group as a precursor structure is reacted with a compound having a partial structure (1) and a partial structure capable of reacting with a hydroxyl group (carboxylic acid, ester, carbonyl halide, etc.) to obtain a methacrylic polymer block (a1). ) Can be formed. Further, a polymer block containing a hydroxyl group protected by a protective group as a precursor structure can be similarly formed into a methacrylic polymer block (a1) after removing the protective group to form a hydroxyl group.

The polymer block containing an amino group as a precursor structure has a partial structure (1) and a partial structure capable of reacting with an amino group (carboxylic acid, carboxylic anhydride, ester, carbonyl halide, aldehyde group, isocyanate group, etc.). The methacrylic polymer block (a1) can be formed by reacting with a compound. Further, a polymer block containing an amino group protected by a protecting group as a precursor structure can similarly form a methacrylic polymer block (a1) after removing the protecting group to form an amino group.

The polymer block containing a thiol group as a precursor structure has a partial structure (1) and a partial structure capable of reacting with a thiol group (carboxylic acid, carboxylic anhydride, ester, carbonyl halide, isocyanate group, carbon-carbon double bond). And the like) to form a methacrylic polymer block (a1). In addition, a polymer block containing a thiol group protected by a protecting group as a precursor structure can similarly form a methacrylic polymer block (a1) after removing the protecting group to form a thiol group.

The polymer block containing an isocyanate group as a precursor structure can form a methacrylic polymer block (a1) by reacting with a compound having a partial structure (1) and a partial structure capable of reacting with an isocyanate group (such as a hydroxyl group). .

In the production of the (meth)acrylic block copolymer (I), as a method for forming the methacrylic polymer block (a1), from the viewpoint of easily introducing the partial structure (1) directly, the above general formula (2) The method of polymerizing the monomer containing the methacrylic acid ester represented by the above), typically, the method of living anion polymerization is preferable.

[(Meth)acrylic copolymer (II)]
The active energy ray-curable composition of the present invention has a weight average molecular weight of 3,000 or more, which is smaller than the weight average molecular weight of the (meth)acrylic block copolymer (I), and the (meth)acrylic block copolymer It has 70 mol% or more of the same monomer unit as the monomer unit constituting the acrylic polymer block (b) having no active energy ray-curable group of the polymer (I), and is radically polymerizable unsaturated. A (meth)acrylic copolymer (II) having a bond is included. The (meth)acrylic copolymer (II) may be a homopolymer or a copolymer composed of a plurality of monomer units.

The content of the same monomer unit as the monomer unit constituting the acrylic polymer block (b) of the (meth)acrylic block copolymer (I) in the (meth)acrylic copolymer (II) is , 70 mol% or more, preferably 80 mol% or more. If it is 70 mol% or more, the (meth)acrylic copolymer (II) preferentially becomes compatible with the acrylic polymer block (b) of the (meth)acrylic block copolymer (I), and A liquid-like or gel-like transition easily occurs between the low temperature and the low temperature.

Monomer constituting the acrylic polymer block (b) having no active energy ray-curable group of the (meth)acrylic block copolymer (I), which the (meth)acrylic copolymer (II) has The same monomer unit as the body unit means a monomer unit of the same kind as the monomer unit constituting the acrylic polymer block (b), and the (meth)acrylic copolymer (II) May contain at least one monomer unit of the monomer units constituting the acrylic polymer block (b) in the above content, and for example, the acrylic polymer block (b) When contains two or more kinds of monomer units, it is sufficient that the total of them satisfies the above content. For example, when the acrylic polymer block (b) contains two kinds of monomer units, the (meth)acrylic copolymer (II) contains only one kind of monomer units, The content may satisfy the above range, or the content of the two types of monomer units may be included and the content may satisfy the above range.

In the case where the acrylic polymer block (b) contains two or more kinds of monomer units, the (meth)acrylic copolymer (II) is an acrylic-based polymer of the (meth)acrylic block copolymer (I). The (meth)acrylic copolymer (II) is preferred because it is preferentially compatible with the united block (b) and the liquid-gel transition easily occurs more effectively between high temperature and low temperature. Preferably contains all types of monomer units (for example, two or more types of monomer units) constituting the acrylic polymer block (b), and the acrylic polymer block (b ), and the monomer unit having the largest content on the basis of mol% of the monomer units constituting (), and the mol% of the monomer units constituting (meth)acrylic copolymer (II) The monomer unit having the highest content on the basis is the same kind, and the monomer unit having the highest content on the mol% basis among the monomer units constituting the acrylic polymer block (b). The content of the unit (mol %) and the content of the monomer unit having the largest content on the mol% basis among the monomer units constituting the (meth)acrylic copolymer (II) ( More preferably, the absolute value of the difference with the (mol %) is 30 mol% or less, more preferably 20 mol% or less, particularly preferably 10 mol% or less, and 5 mol% or less. Is most preferable, and may be 0 mol %.

The (meth)acrylic copolymer (II) has, for example, a main chain made of a copolymer containing an acrylic acid ester as a monomer unit and a side chain containing a radically polymerizable unsaturated bond and bonded to the main chain. . Examples of the radical-polymerizable unsaturated bond include (meth)acryloyl group (may be a (meth)acryloyloxy group), vinyl group, (meth)allyl group, vinyloxy group, 1,3-dienyl group, styryl group. And so on. Among these, from the viewpoint of active energy ray curability, a (meth)acryloyl group, a vinyl group, and a (meth)allyl group are preferable, and from the viewpoint of reactivity with a mercapto group, a vinyl group, a (meth)allyl group, A 1,3-dienyl group is preferred.

For example, when the radical-polymerizable unsaturated bond is a (meth)allyl group, the (meth)acrylic copolymer (II) has an active energy containing the partial structure (1) represented by the general formula (1). It may contain a methacrylic polymer block (a2) having a linear curable group. The monomer units constituting the methacrylic polymer block (a2) can be the same as the methacrylic polymer block (a1) contained in the (meth)acrylic block copolymer (I).

The content of the methacrylic polymer block (a2) in the (meth)acrylic copolymer (II) is preferably 40% by mass or less, and 30% by mass from the viewpoint of reducing the viscosity when it becomes liquid at high temperature. % Or less is more preferable, and 20% by mass or less is particularly preferable.

The (meth)acrylic copolymer (II) is, for example, one or more polymerizable compounds (d) having one or two or more (meth)acrylic acid ester (c) and a reactive functional group. To obtain a (meth)acrylic copolymer having a reactive functional group by copolymerization with, and a functional group reactive with the reactive functional group of this (meth)acrylic copolymer and a radical polymerizable unsaturated A radically polymerizable unsaturated bond is introduced into a side chain of the (meth)acrylic copolymer by reacting one or more compounds (e) having a bond with a (meth)acrylic copolymer. It can be obtained by a method including and. As the (meth)acrylic acid ester (c), for example, a unit amount which constitutes the acrylic polymer block (b) having no active energy ray-curable group of the (meth)acrylic block copolymer (I) It is preferable to select one that can give the same monomer unit as the body unit. Further, the production method is not limited to this, and can be obtained by using the same production method as that for the (meth)acrylic block copolymer (I).

The polymerizable compound (d) preferably has at least one reactive functional group selected from the group consisting of epoxy groups and hydroxyl groups. Epoxy groups and hydroxyl groups are preferable because they have good reactivity with the compound (e).

Examples of the polymerizable compound (d) having an epoxy group as a reactive functional group include acrylic acid esters having an epoxy group such as glycidyl acrylate and 3,4-epoxycyclohexyl acrylate.

Examples of the polymerizable compound (d) having a hydroxyl group as a reactive functional group include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, and 2-hydroxypropyl acrylate. ..

The (meth)acrylic copolymer (II) is a monomer unit obtained by reacting with a monomer unit derived from the (meth)acrylic acid ester (c) and the polymerizable compound (d) (compound (e)). May be present), a monomer unit derived from another polymerizable compound may be further included. Examples of other polymerizable compounds include aromatic vinyl compounds such as styrene and vinyltoluene.

The compound (e) has at least one functional group capable of reacting with the reactive functional group (epoxy group, hydroxyl group and the like) of the polymerizable compound (d) such as a carboxyl group and an isocyanate group.

Specific examples of the compound (e) having a carboxyl group include (meth)acrylic acid, a dimer of (meth)acrylic acid (for example, "Aronix M5600" manufactured by Toagosei Co., Ltd.), and caprolactone-modified (meth)acrylic. A compound obtained by a ring-opening reaction of an acid (for example, ω-carboxy-polycaprolactone monoacrylate, “Aronix M5300” manufactured by Toagosei Co., Ltd.), and a carboxylic acid anhydride (meth)acrylate (for example, phthalic acid Examples thereof include monohydroxyethyl acrylate, "Aronix M5400" manufactured by Toagosei Co., Ltd.), and β-acryloyloxyethyl hydrogen succinate (for example, "NK Ester A-SA" manufactured by Shin Nakamura Chemical Co., Ltd.).

Specific examples of the compound (e) having an isocyanate group include methacryloyloxyethyl isocyanate (for example, "Karenzu MOI" manufactured by Showa Denko KK).

The weight average molecular weight of the (meth)acrylic copolymer (II) is 3,000 or more, preferably 6,000 or more, and more preferably 10,000 or more from the viewpoint of handleability, fluidity and mechanical properties. . Further, it is preferably smaller than the weight average molecular weight of the (meth)acrylic block copolymer (I) and smaller than 80% of the weight average molecular weight of the (meth)acrylic block copolymer (I). When the weight average molecular weight is 3,000 or more, it is possible to obtain the characteristics that it is liquid at high temperature and becomes gel at low temperature. When it becomes liquid, a low viscosity can be achieved. Furthermore, when the weight average molecular weight is within the above range, an active energy ray-curable composition in which the cured product after irradiation with active energy rays has excellent oil resistance can be obtained.

[Compound (III)]
The active energy ray-curable composition of the present invention contains the compound (III) having two or more mercapto groups in one molecule.

The number of mercapto groups contained in the compound (III) is 2 or more in one molecule, and more preferably 3 or more.

The total amount of mercapto groups contained in the compound (III) contained in the active energy ray-curable composition of the present invention is (meth)acrylic block copolymer (I) contained in the active energy ray-curable composition of the present invention. And the total amount of carbon-carbon double bonds in the (meth)acrylic copolymer (II) is preferably 0.1 to 5.0 molar equivalents, and 0.2 to 4.5 molar equivalents. Is more preferable, and 0.3 to 4.0 molar equivalents is even more preferable.

From the viewpoint of curability, the compound (III) is preferably a polyfunctional thiol, and more preferably a polyfunctional thiol having 3 or more mercapto groups per molecule. The upper limit of the number of mercapto groups is not particularly limited, but can be, for example, 10 or less, 7 or less, 5 or less, and further 4 or less.

Specific examples of the compound (III) include, for example, butanediol bis(thioglycolate), ethylene glycol bisthiopropionate, 1,4-butanediol bisthiopropionate, trimethylolpropane tris(3-mercaptobutyrate). Rate), 1,3,5-tris[2-(3-sulfanylbutanoyloxy)ethyl]-1,3,5-triazinane-2,4,6-trione, trimethylolethane tris(3-mercaptobutyrate) ), trimethylolpropane tris(thioglycolate), trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptobutyrate). Rate), pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate) , Dipentaerythritol hexakis (thioglycolate), dipentaerythritol hexakis (3-mercaptobutyrate), thiol-functionalized polydimethylsiloxane, thiol-terminated polysulfide, tripentaerythritol octakis (thioglycolate), mercaptan Terminally propoxylated glycerol, phthalic acid di(1-mercaptoethyl ester), phthalic acid di(2-mercaptopropyl ester), phthalic acid di(3-mercaptobutyl ester), phthalic acid di(3-mercaptoisobutyl ester) , Ethylene glycol bis(3-mercaptobutyrate), propylene glycol bis(3-mercaptobutyrate) diethylene glycol bis(3-mercaptobutyrate), octanediol bis(3-mercaptobutyrate), 1,3-butanediol bis (3-mercaptobutyrate), 1,4-butanediol bis(3-mercaptobutyrate), neopentyl glycol bis(3-mercaptobutyrate), 1,6-hexanediol bis(3-mercaptobutyrate), 1,8-octanediol bis(3-mercaptobutyrate), 1,9-nonanediol bis(3-mercaptobutyrate), cyclohexane-1,4-dimethanol bis(3-mercaptobutyrate), diethylene glycol Rubis(3-mercaptobutyrate), triethylene glycol bis(3-mercaptobutyrate), polyethylene glycol bis(3-mercaptobutyrate), dipropylene glycol bis(3-mercaptobutyrate), tripropylene glycol bis(3 -Mercaptobutyrate), polypropylene glycol bis(3-mercaptobutyrate), polytetramethylene ether glycol bis(3-mercaptobutyrate), cyclohexane-1,4-dimethanol ethylene oxide adduct bis(3-mercaptobutyrate) Rate), hydrogenated bisphenol A ethylene oxide adduct bis(3-mercaptobutyrate), cyclohexane-1,4 bisphenol A propylene oxide adduct bis(3-mercaptobutyrate), glycerol tris(3-mercaptobutyrate) ), diglycerol tetrakis(3-mercaptobutyrate), ditrimethylolpropane tetrakis(3-mercaptobutyrate), hydrogenated bisphenol A bis(3-mercaptobutyrate), bisphenol A dihydroxyethyl ether (3-mercaptobutyrate) , 4,4′-(9-fluorenylidene)bis(2-phenoxyethyl(3-mercaptobutyrate)), ethylene glycol bis(2-mercaptopropionate), propylene glycol bis(2-mercaptopropionate), Diethylene glycol bis(2-mercaptopropionate), 1,4-butanediol bis(2-mercaptopropionate), octanediol bis(2-mercaptopropionate), trimethylolpropane tris(2-mercaptopropionate) ), pentaerythritol tetrakis (2-mercaptopropionate), dipentaerythritol hexakis (2-mercaptopropionate), ethylene glycol bis (3-mercaptoisobutyrate), propylene glycol bis (3-mercaptoisobutyrate) ), diethylene glycol bis(3-mercaptoisobutyrate), 1,4-butanediol bis(3-mercaptoisobutyrate), octanediol bis(3-mercaptoisobutyrate), trimethylolpropane tris(3-mercaptoisobutyrate). Butyrate), pentaerythritol tetrakis (3-mercaptoisobutyrate), dipentaerythritol hexakis (3-mercaptoisobutyrate) ), ethylene glycol bis(2-mercaptoisobutyrate), propylene glycol bis(2-mercaptoisobutyrate), diethylene glycol bis(2-mercaptoisobutyrate), 1,4-butanediol bis(2-mercapto) Isobutyrate), octanediol bis(2-mercaptoisobutyrate), trimethylolpropane tris(2-mercaptoisobutyrate), pentaerythritol tetrakis(2-mercaptoisobutyrate), dipentaerythritol hexakis(2- Mercaptoisobutyrate), ethylene glycol bis(4-mercapto valerate), propylene glycol bis(4-mercapto isovalerate), diethylene glycol bis(4-mercapto valerate), 1,4-butanediol bis(4-mercapto) Valerate), octanediol bis(4-mercapto valerate), trimethylolpropane tris(4-mercapto valerate), pentaerythritol tetrakis (4-mercapto valerate), dipentaerythritol hexakis (4-mercapto valerate). , Ethylene glycol bis(3-mercapto valerate), propylene glycol bis(3-mercapto valerate), diethylene glycol bis(3-mercapto valerate), 1,4-butanediol bis(3-mercapto valerate), octane diol Bis(3-mercaptovalerate), trimethylolpropane tris(3-mercaptovalerate), pentaerythritol tetrakis(3-mercaptovalerate), dipentaerythritol hexakis(3-mercaptovalerate), ethylene glycol bis(3) -Mercapto-3-phenylpropionate), propylene glycol bis(3-mercapto-3-phenylpropionate), diethylene glycol bis(3-mercapto-3-phenylpropionate), 1,4-butanediol bis(3-mercapto) -3-phenylpropionate), octanediol bis(3-mercapto-3-phenylpropionate), trimethylolpropane tris(3-mercapto-3-phenylpropionate), tris-2-(3-mercapto-3-). Phenylpropionate) ethyl isocyanurate, pentaerythritol tetrakis (3-mercapto-3-phenylpropionate), dipentaerythritol hex Sakis(3-mercapto-3-phenylpropionate), trimethylene glycol bis(thioglycolate), propylene glycol bis(thioglycolate), 1,3-butanediol bis(thioglycolate), neopentyl glycol bis( Thioglycolate), 1,8-octanediol bis(thioglycolate), 1,9-nonanediol bis(thioglycolate), cyclohexane-1,4-dimethanol bis(thioglycolate), diethylene glycol bis(thio) Glycolate), triethylene glycol bis (thioglycolate), polyethylene glycol bis (thioglycolate), dipropylene glycol bis (thioglycolate), tripropylene glycol bis (thioglycolate), polypropylene glycol bis (thioglycolate) ), polytetramethylene ether glycol bis(thioglycolate), cyclohexane-1,4-dimethanol ethylene oxide adduct bis(thioglycolate), hydrogenated bisphenol A ethylene oxide adduct bis(thioglycolate), Cyclohexane-1,4-dimethanol propylene oxide adduct bis(thioglycolate), hydrogenated bisphenol A propylene oxide adduct bis(thioglycolate), glycerol tris(thioglycolate), diglycerol tetrakis(thioglycolate) Rate), ditrimethylolpropane tetrakis (thioglycolate), dipentaerythritol hexakis (thioglycolate), trimethylene glycol bis(3-mercaptopropionate), propylene glycol bis(3-mercaptopropionate), 1 ,3-butanediol bis(3-mercaptopropionate), neopentyl glycol bis(3-mercaptopropionate), 1,6-hexanediol bis(3-mercaptopropionate), 1,8-octanediol Bis(3-mercaptopropionate), 1,9-nonanediol bis(3-mercaptopropionate), cyclohexane-1,4-dimethanol bis(3-mercaptopropionate), diethylene glycol bis(3-mercapto) Propionate), triethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), dipropylene glycol bis(3-mercaptopropionate) ), tripropylene glycol bis(3-mercaptopropionate), polypropylene glycol bis(3-mercaptopropionate), polytetramethylene ether glycol bis(3-mercaptopropionate), cyclohexane-1,4-di Methanol ethylene oxide adduct bis(3-mercaptopropionate), hydrogenated bisphenol A ethylene oxide adduct bis(3-mercaptopropionate), cyclohexane-1,4-dimethanol propylene oxide adduct bis( 3-mercaptopropionate), hydrogenated bisphenol A propylene oxide adduct bis(3-mercaptopropionate), glycerol tris(3-mercaptopropionate), diglycerol tetrakis(3-mercaptopropionate), Examples thereof include ditrimethylolpropane tetrakis (3-mercaptopropionate).

As the compound (III), one type may be used alone, or two or more types may be used in combination. Among these compounds (III), trimethylolpropane tris(3-mercaptobutyrate), 1,3,5-tris[2-(3-sulfanylbutanoyloxy)ethyl]-1,3,5-triazinane- 2,4,6-trione, trimethylolethane tris(3-mercaptobutyrate), trimethylolpropane tris(thioglycolate), trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercapto Propionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(thioglycolate), pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercapto) Propionate), dipentaerythritol hexakis(3-mercaptopropionate), dipentaerythritol hexakis(thioglycolate), dipentaerythritol hexakis(3-mercaptobutyrate), glycerol tris(3-mercaptobutyrate) Rate), diglycerol tetrakis(3-mercaptobutyrate), ditrimethylolpropane tetrakis(3-mercaptobutyrate), trimethylolpropane tris(2-mercaptopropionate), pentaerythritol tetrakis(2-mercaptopropionate). , Dipentaerythritol hexakis (2-mercaptopropionate) and the like, and polyfunctional thiols having 3 or more mercapto groups per molecule are preferable, and further pentaerythritol tetrakis (3-mercaptobutyrate) or pentaerythritol tetrakis (3- Mercaptopropionate) is particularly preferred.

The content of the compound (III) is preferably 0.1 to 10 parts by mass and more preferably 0.1 to 8 parts by mass with respect to 100 parts by mass of the active energy ray-curable composition of the present invention. If it is 0.1 part by mass or more, the curability of the active energy ray-curable composition will be good, and if it is 10 parts by mass or less, the active energy ray-curable composition and its cured product will have a low odor.

In the active energy ray-curable composition of the present invention, the methacrylic polymer block (a1) is added to the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). The content is 5% by mass or more, preferably 6% by mass or more, and more preferably 7% by mass or more. Further, it is 35 mass% or less, preferably 30 mass% or less, and more preferably 25 mass% or less. When the content of the methacrylic polymer block (a1) is within the above range, an active energy ray-curable composition that is liquid at high temperature and gel at low temperature can be obtained.

When the (meth)acrylic copolymer (II) has a methacrylic polymer block (a2), the (meth)acrylic block copolymer ((a) contained in the active energy ray-curable composition of the present invention ( The total content of the methacrylic polymer block (a1) and the methacrylic polymer block (a2) with respect to the total mass of I) and the (meth)acrylic copolymer (II) is 7% by mass or more. It is preferably 8% by mass or more, more preferably 9% by mass or more. Further, it is preferably 35% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less. When the total content of the methacrylic polymer block (a1) and the methacrylic polymer block (a2) is within the above range, an active energy ray-curable composition that is liquid at high temperature and gel at low temperature can be obtained. It can be easily obtained.

The mass ratio (I)/(II) of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) in the active energy ray-curable composition of the present invention is 10 /90 to 50/50 is preferable, and 10/90 to 40/60 is more preferable. When the content of the (meth)acrylic copolymer (II) is 50% by mass or more, the viscosity tends to be low, and when it is 90% by mass or less, the composition tends to be gel at low temperature.

[Photopolymerization initiator (IV)]
The active energy ray-curable composition of the present invention may contain a photopolymerization initiator (IV). Examples of the photopolymerization initiator (IV) include acetophenones (eg, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-[4-(2-hydroxy). Ethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpho (Linophenyl)-1-butanone, etc.), benzophenones (eg, benzophenone, benzoylbenzoic acid, hydroxybenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, acrylated benzophenone, etc.), Michler's ketones (eg, Michler's ketone, etc.) And carbonyl compounds such as benzoins (eg, benzoin, benzoin methyl ether, benzoin isopropyl ether); sulfur compounds such as tetramethylthiuram monosulfide, thioxanthones (eg, thioxanthone, 2-chlorothioxanthone); acylphos Phosphorus compounds such as fin oxides (eg, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide); titanocenes (eg, bis(η5 -2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, etc.); azo compounds (eg, azobis Isobutyl nitrile etc.) and the like. Among these, acetophenones and benzophenones are preferable. These photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator (IV) is 0.01 to 100 parts by mass based on the total amount of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). 10 parts by mass is preferable, and 0.05 to 8 parts by mass is more preferable. If it is 0.01 part by mass or more, the curability of the active energy ray-curable composition will be good, and if it is 10 parts by mass or less, the heat resistance of the obtained cured product will be good.

The active energy ray-curable composition of the present invention may contain a sensitizer in addition to the photopolymerization initiator (IV). Examples of the sensitizer include n-butylamine, di-n-butylamine, tri-n-butylphosphine, allylthiourea, triethylamine, diethylaminoethylmethacrylate and the like. Of these, diethylaminoethyl methacrylate and triethylamine are preferable.

When the photopolymerization initiator (IV) and the sensitizer are used in combination, the mass ratio of the photopolymerization initiator (IV) and the sensitizer is preferably 10:90 to 90:10, and 20:80. The range of up to 80:20 is more preferable.

The active energy ray-curable composition of the present invention may further contain a solvent. The viscosity can be adjusted by including a solvent. In addition, by including a solvent, various components in the active energy ray-curable composition can be easily dissolved or dispersed.

Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and chlorobenzene; aliphatic or alicyclic hydrocarbons such as pentane, hexane, cyclohexane and heptane; halogenated carbonization such as carbon tetrachloride, chloroform and ethylene dichloride. Hydrogen; nitro compounds such as nitromethane and nitrobenzene; ethers such as diethyl ether, methyl t-butyl ether, tetrahydrofuran and 1,4-dioxane; esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate; dimethylformamide, etc. Amides; alcohols such as methanol, ethanol and propanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone.

When the solvent is contained, its content is 100 parts by mass with respect to the total amount of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) used in the present invention. , 1 to 50 parts by mass is preferable, and 2 to 10 parts by mass is more preferable.

Further, in the active energy ray-curable composition of the present invention, the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) of the present invention are used unless the effects of the present invention are impaired. Other than the above), a reactive diluent exhibiting polymerizability may be contained. The reactive diluent is not particularly limited as long as it is a compound exhibiting polymerizability, and for example, styrene, indene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, pt-butoxystyrene, p -Styrene derivatives such as chloromethylstyrene, p-acetoxystyrene and divinylbenzene; fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate and vinyl cinnamate; (meth)acrylic acid Methyl, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, (meth) ) T-butyl acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate , 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, (meth)acrylic acid Stearyl, isostearyl (meth)acrylate, benzyl (meth)acrylate, allyl (meth)acrylate, 3-methyl-3-butenyl methacrylate, isobornyl (meth)acrylate, bornyl (meth)acrylate, (meth ) Tricyclodecanyl acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, ( 2-Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, (meth)acrylic Acid ethoxydiethylene glycol, phenoxyethyl (meth)acrylate, polyethylene glycol monoester (meth)acrylic acid, polypropylene glycol monoester (meth)acrylic acid, methoxyethylene glycol (meth)acrylic acid, ethoxyethyl acrylate (meth)acrylic acid, ( Methoxy)polyethylene glycol (meth), methoxypolypropylene glycol (meth)acrylate, dimethyl (meth)acrylate Minoethyl, diethylaminoethyl (meth)acrylate, 7-amino-3,7-dimethyloctyl (meth)acrylate, 4-(meth)acryloylmorpholine, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethoxytri(meth) ) Acrylate, pentaerythritol tri(meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tricyclodecanediyl dimethanol di(meth)acrylate, polyethylene Glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, bisphenol A diglycidyl ether adducts with both ends (meth)acrylic acid, pentaerythritol tetra(meth)acrylate, 2,4,6-trioxohexahydro-1,3,5-triazine-1,3,5-trisethanol Tri(meth)acrylate, N,N'-bis[2-((meth)acryloyloxy)ethyl]-N"-(2-hydroxyethyl)-1,3,5-triazine-2,4,6(1H ,3H,5H)-Trione, tricyclodecane dimethanol di(meth)acrylate, bisphenol A ethylene oxide or propylene oxide adduct diol di(meth)acrylate, hydrogenated bisphenol A ethylene oxide or propylene oxide. (Meth)acrylic acid derivatives such as di(meth)acrylate of diol, epoxy (meth)acrylate obtained by adding (meth)acrylate to diglycidyl ether of bisphenol A, cyclohexanedimethanol di(meth)acrylate, etc. Dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, trimethylolpropane tri(meth) ) Acrylate, trimethylolpropane propylene oxide-modified tri(meth)acrylate, trimethylolpropane ethylene oxide-modified tri(meth)acrylate G, isocyanuric acid ethylene oxide-modified di(meth)acrylate, isocyanuric acid ethylene oxide-modified tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tri Polyfunctional (meth)acrylates such as propylene glycol di(meth)acrylate and diglycerin ethylene oxide modified (meth)acrylate; pentaerythritol triallyl ether, allyl phenyl ether, allyl glycidyl ether, ethylallyl carbonate, glycerin monoallyl ether, diallyl ether Allyl group-containing monomers such as trimethylolpropane diallyl ether, diallyldimethylammonium chloride, trimethylolpropane triallyl ether, pentaerythritol triallyl ether, triallyl isocyanurate, and pentaerythritol tetraallyl ether; bisphenol A type epoxy acrylate resin; Epoxy acrylate resin such as phenol novolac type epoxy acrylate resin and cresol novolac type epoxy acrylate resin; carboxyl group modified epoxy acrylate resin; polyol (polytetramethylene glycol, polyester glycol of ethylene glycol and adipic acid, ε-caprolactone modified polyester diol) , Polypropylene glycol, polyethylene glycol, polycarbonate diol, hydroxyl-terminated hydrogenated polyisoprene, hydroxyl-terminated polybutadiene, hydroxyl-terminated polyisobutylene, etc.) and organic isocyanates (tolylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, etc.) Urethane acrylate obtained by reacting the urethane resin obtained from the above with a hydroxyl group-containing (meth)acrylate (hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, pentaerythritol triacrylate, etc.) Resins; resins obtained by introducing a (meth)acrylic group into the above polyol via an ester bond; polyester acrylate resins; epoxidized soybean oil, epoxy compounds such as benzyl epoxystearate, and the like. Among them, from the viewpoint of curability, n-octyl acrylate, isooctyl acrylate, acrylate monomers such as 2-ethylhexyl acrylate, pentaerythritol tetraallyl ether, pentaerythritol triallyl ether, trimethylolpropane diallyl ether, glycerin monoallyl. It is preferable to use an allyl group-containing monomer such as ether. These reactive diluents may be used alone or in combination of two or more.

The active energy ray-curable composition of the present invention does not impair the effects of the present invention, and within a range that does not significantly impair the curability thereof, a plasticizer, a tackifier, a softening agent, a filler, a stabilizer, Various additives having no active energy ray-curable group such as antioxidants, antioxidants, pigments and dyes may be contained. These various additives may be used alone or in combination of two or more.

The additive having no active energy ray-curable group may be an organic compound or an inorganic compound.

The method for producing the active energy ray-curable composition of the present invention is not particularly limited, and for example, each component can be prepared by using a known mixing or kneading device such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. It can be produced by mixing at a temperature within the range of 100 to 250°C. Further, it may be produced by dissolving the respective components in a solvent and mixing them, and then distilling off the solvent.

The active energy ray used for curing the active energy ray-curable composition of the present invention can be irradiated using a known device. In the case of an electron beam (EB), an accelerating voltage of 0.1 to 10 MeV and an irradiation dose of 1 to 500 kGy are suitable.

For the ultraviolet irradiation, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an LED or the like which emits light in the wavelength range of 150 to 450 nm can be used. Integrated light quantity of active energy rays, usually in the range of 10~20000mJ / cm ^2, the range of 30~5000mJ / cm ² is preferred. If it is less than 10 mJ/cm ^{2, the} curability of the active energy ray-curable composition tends to be insufficient, and if it is more than 20000 mJ/cm ² , the active energy ray-curable composition may deteriorate.

The relative humidity when the active energy ray-curable composition of the present invention is irradiated with the active energy ray is preferably 30% or less from the viewpoint of suppressing decomposition of the active energy ray-curable composition. % Or less is more preferable.

The active energy ray-curable composition of the present invention may be further heated during or after the irradiation with the active energy ray, if necessary, to accelerate the curing. The heating temperature is preferably in the range of 40 to 130°C, more preferably 50 to 100°C.

The application of the active energy ray-curable composition of the present invention includes automobiles, home appliances, construction, civil engineering, sports, displays, optical recording devices, optical devices, semiconductors, batteries, curable resins used in the fields of printing, and the like. Adhesives, tapes, films, sheets, mats, sealing materials, encapsulating materials, coating materials, potting materials, inks, printing plate materials, anti-vibration materials, foams, heat dissipation materials, prepregs, gaskets, packings, etc. ..

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

In addition, AMA, MMA, 2-MEA, BA, and GA in the examples represent allyl methacrylate, methyl methacrylate, 2-methoxyethyl acrylate, butyl acrylate, and glycidyl acrylate, respectively.

In the following Synthetic Examples, Examples and Comparative Examples, the raw materials were used after being dried and purified by a conventional method and deaerated with nitrogen, and the materials were transferred and supplied under a nitrogen atmosphere.
The evaluation methods adopted in the following synthesis examples, examples and comparative examples are shown below.

[Monomer consumption rate]
Regarding the consumption rate of each monomer after polymerization in the following synthesis example, 0.5 mL of the reaction solution was sampled, put in 0.5 mL of methanol and mixed, and then 0.1 mL was sampled from the mixed solution to determine the weight. ¹ H-NMR measurement was carried out under the following measurement conditions by dissolving in 0.5 mL of chloroform, and a peak derived from a proton directly connected to a carbon-carbon double bond of (meth)acrylic acid ester used as a monomer ( It was calculated from the change in the ratio of the chemical shift value of 5.79 to 6.37 ppm) and the integral value of the peak (chemical shift value of 7.00 to 7.38 ppm) derived from the proton directly connected to the aromatic ring of toluene used as the solvent. ..
( ¹ H-NMR measurement condition)
Apparatus: JEOL Ltd. nuclear magnetic resonance apparatus "JNM-ECX400"
Temperature: 25°C

[Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw/Mn)]
In the following synthesis example, GPC measurement of the obtained polymer was performed under the following measurement conditions, and the values of standard polystyrene-equivalent weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were measured. I asked.
(GPC measurement conditions)
Device: Tosoh Corp. GPC device "HLC-8220GPC"
Separation column: "TSKgel SuperMultipore HZ-M (column diameter = 4.6 mm, column length = 15 cm)" manufactured by Tosoh Corporation (using two in series)
Eluent: Tetrahydrofuran Eluent flow rate: 0.35 mL/min Column temperature: 40°C
Detection method: Differential refractive index (RI)

[Content of Methacrylic Polymer Block (a1) in (Meth)acrylic Block Copolymer (I)]
The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I) was 0.01 g of the (meth)acrylic block copolymer obtained in the following synthesis example, and Dissolved in 0.5 mL, ¹ H-NMR measurement was performed under the following measurement conditions, and peaks derived from each ester chain of (meth)acrylic acid ester used as a monomer (chemical shift values 2.5 to 5) It was calculated from the ratio of the integrated value of 0.0 ppm).
( ¹ H-NMR measurement condition)
Apparatus: JEOL Ltd. nuclear magnetic resonance apparatus "JNM-ECX400"
Temperature: 25°C

[Content of Methacrylic Polymer Block (a2) in (Meth)acrylic Copolymer (II)]
The content of the methacrylic polymer block (a2) in the (meth)acrylic copolymer (II) was 0.01 g of the (meth)acrylic copolymer obtained in the following synthesis example, and deuterated chloroform of 0. Dissolved in 5 mL, ¹ H-NMR measurement was performed under the following measurement conditions, and peaks derived from each ester chain of (meth)acrylic acid ester used as a monomer (chemical shift value 2.5 to 5.0 ppm) ) Was calculated from the ratio of the integrated values.
( ¹ H-NMR measurement condition)
Apparatus: JEOL Ltd. nuclear magnetic resonance apparatus "JNM-ECX400"
Temperature: 25°C

[Method for calculating content of methacrylic polymer block (a1) based on total mass of (meth)acrylic block copolymer (I) and (meth)acrylic copolymer (II)]
Content of methacrylic polymer block (a1) with respect to the total mass of (meth)acrylic block copolymer (I) and (meth)acrylic copolymer (II) contained in the active energy ray-curable composition. Was dissolved in 0.5 mL of deuterated chloroform to dissolve 10 mg of the active energy ray-curable composition of the present invention, and ¹ H-NMR measurement was performed under the following measurement conditions. It was calculated from the ratio of the integrated values of the peaks (chemical shift value 2.5 to 5.0 ppm) derived from each ester chain.
( ¹ H-NMR measurement condition)
Apparatus: JEOL Ltd. nuclear magnetic resonance apparatus "JNM-ECX400"
Temperature: 25°C

[The total content of the methacrylic polymer block (a1) and the methacrylic polymer block (a2) based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). Quantity calculation method]
The methacrylic polymer block (a1) and the methacrylic polymer based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) contained in the active energy ray-curable composition. The total content of the polymer block (a2) is determined by dissolving 10 mg of the active energy ray-curable composition of the present invention in 0.5 mL of deuterated chloroform and conducting ¹ H-NMR measurement under the following measurement conditions. It was calculated from the ratio of the integrated values of the peaks (chemical shift value 2.5 to 5.0 ppm) derived from each ester chain of the (meth)acrylic acid ester used as.
( ¹ H-NMR measurement condition)
Apparatus: JEOL Ltd. nuclear magnetic resonance apparatus "JNM-ECX400"
Temperature: 25°C

[Viscosity at high temperature]
The viscosities of the active energy ray-curable compositions obtained in the following Examples and Comparative Examples were measured by the following method using a viscosity/viscoelasticity measuring device (HAAKE MARS III manufactured by Thermo Fisher Scientific Co., Ltd.).
1 g of the active energy ray-curable composition was dropped onto a φ35 mm, 1° inclined cone plate to form a coating film. The viscosity (Pa·s) was measured under the conditions of a measurement temperature of 80° C., a measurement gap of 0.05 mm, and a shear rate of 1 (1/s) using the steady flow viscosity measurement mode as the measurement mode. When the viscosity is 2000 Pa·s or less, it can be regarded as “liquid” in the present invention, and can be easily applied to a member at high temperature.

[Properties at low temperature]
The properties of the active energy ray-curable compositions obtained in the following Examples and Comparative Examples at low temperature were evaluated by the presence or absence of spinnability of the compositions.
Specifically, the active energy ray-curable composition was molded into a sheet having a thickness of 1 mm, and the obtained sheet-shaped composition was touched with fingers at room temperature of 25° C., and evaluated according to the following criteria.
○: Liquid matter does not adhere to fingers (no spinnability)
×: Liquid adheres to fingers (has spinnability)
In the case of evaluation of “◯” having no spinnability, it can be regarded as “gel-like” in the present invention.

[Evaluation of oil resistance]
1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one as a photopolymerization initiator was added to the active energy ray-curable compositions obtained in the following Examples and Comparative Examples. (Irgacure (registered trademark) 2959 manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed in an amount of 3% by mass. Then, a 1 mm-thick polytetrafluoroethylene tape was attached to the release surface of the release PET film (K1504, manufactured by Toyobo Co., Ltd.) so that a space of 4 cm in width and 4 cm in length was formed. In this space, the prepared active energy ray-curable composition was applied, and another release PET film (K1504, manufactured by Toyobo Co., Ltd.) was placed on the composition, and then the surface was made uniform using a laminating roller. Pressed. Next, a cured product of the active energy ray-curable composition is obtained by irradiating the release PET film with ultraviolet rays at 2,000 mJ/cm2 using an ultraviolet irradiation device (12A12-A10-HD3A, manufactured by GS Yuasa Co., Ltd., metal halide lamp). Got The obtained cured product was cut into a strip having a thickness of 1 mm, a width of 20 mm, and a length of 50 mm, and immersed in an autofluid solution (Toyota genuine autofluid WS) at 150° C. for 70 hours, and then a weight change rate and a volume change. The rate was evaluated.
Weight change rate [%]={(weight change before and after immersion)/(weight before immersion)}×100
Volume change rate [%]={(volume change before and after immersion)/(volume before immersion)}×100

[Synthesis Example 1: Synthesis of (meth)acrylic block copolymer (I-1)]
(Process (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and replaced with nitrogen, N,N,N′,N″,N″-pentamethyldiethylenetriamine was added as a Lewis base while stirring the solution in the flask. 2.1 g and 42 g of a toluene solution containing 26 mass% of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum as an organoaluminum compound were sequentially added, and then cooled to -30°C. To this was added 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound, and then 119 g of a mixture of 6.2 g of AMA and 113 g of MMA as a monomer was added all at once to start anionic polymerization. Subsequently, the reaction solution was stirred at −30° C. for 12 hours to sample the reaction solution.
The consumption rate of AMA and MMA in the step (1) was 100%.

(Process (2))
Subsequently, 292 g of 2-MEA as a monomer was added at a rate of 5 g/min while stirring the reaction solution at -30°C. The reaction solution was sampled immediately after the addition of the monomer.
The consumption rate of 2-MEA in the step (2) was 100%.

(Process (3))
While continuously stirring the reaction solution at -30°C, 100 g of a mixture of 5.2 g of AMA and 95 g of MMA as a monomer was added all at once, and the temperature was raised to 25°C. The reaction solution was sampled 300 minutes after the addition of the above mixture.
The consumption rate of AMA and MMA in the step (3) was 100%.

(Process (4))
While continuing to stir the reaction solution at 25° C., 40 g of methanol was added to stop the anionic polymerization, and the methacrylic polymer block (a1)-acrylic polymer block (b)-methacrylic polymer block (a1) was added. (Meth)acrylic block copolymer (hereinafter, referred to as "(meth)acrylic block copolymer (I-1)") which is a triblock copolymer bonded in the order of (a1-b-a1). A solution containing was obtained. The (meth)acrylic block copolymer (I-1) sampled from this solution had Mw of 53,400 and Mw/Mn of 1.07. The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I-1) was 47% by mass.

(Process (5))
Then, the obtained solution was poured into 5,000 g of methanol to deposit an oily precipitate. The oily precipitate was collected and then dried to obtain 420 g of (meth)acrylic block copolymer (I-1).

[Synthesis Example 2: Synthesis of (meth)acrylic block copolymer (I-2)]
(Process (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and replaced with nitrogen, N,N,N′,N″,N″-pentamethyldiethylenetriamine was added as a Lewis base while stirring the solution in the flask. 2.1 g and 42 g of a toluene solution containing 26 mass% of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum as an organoaluminum compound were sequentially added, and then cooled to -30°C. To this was added 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound, and then 155 g of a mixture of 6.2 g of AMA and 149 g of MMA was added at once as a monomer to start anionic polymerization. Subsequently, the reaction solution was stirred at -30°C for 12 hours to sample the reaction solution.
The consumption rates of AMA and MMA in the step (1) were 100%.

(Process (2))
Subsequently, 221 g of 2-MEA as a monomer was added at a rate of 5 g/min while stirring the reaction solution at -30°C. The reaction solution was sampled immediately after the addition of the monomer.
The consumption rate of 2-MEA in the step (2) was 100%.

(Process (3))
Subsequently, 130 g of a mixture of 5.2 g of AMA and 125 g of MMA as a monomer was added all at once while the reaction solution was stirred at -30° C., and then the temperature was raised to 25° C. The reaction solution was sampled 300 minutes after the addition of the above mixture.
The consumption rate of AMA and MMA in the step (3) was 100%.

(Process (4))
While continuing to stir the reaction solution at 25° C., 40 g of methanol was added to stop the anionic polymerization, and the methacrylic polymer block (a1)-acrylic polymer block (b)-methacrylic polymer block (a1) was added. (Meth)acrylic block copolymer (hereinafter, referred to as "(meth)acrylic block copolymer (I-2)"), which is a triblock copolymer in which (a1-b-a1) is bonded in the order of A solution containing was obtained. The Mw of the (meth)acrylic block copolymer (I-2) sampled from this solution was 54,300 and Mw/Mn was 1.09. The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I-2) was 60% by mass.

(Process (5))
Then, the obtained solution was poured into 5,000 g of methanol to deposit an oily precipitate. The oily precipitate was collected and then dried to obtain 420 g of (meth)acrylic block copolymer (I-2).

[Synthesis Example 3: Synthesis of (meth)acrylic block copolymer (I-3)]
(Process (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and replaced with nitrogen, N,N,N′,N″,N″-pentamethyldiethylenetriamine was added as a Lewis base while stirring the solution in the flask. 2.1 g and 42 g of a toluene solution containing 26 mass% of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum as an organoaluminum compound were sequentially added, and then cooled to -30°C. To this was added 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound, and then 119 g of a mixture of 6.2 g of AMA and 113 g of MMA as a monomer was added all at once to start anionic polymerization. Subsequently, the reaction solution was stirred at −30° C. for 12 hours to sample the reaction solution.
The consumption rate of AMA and MMA in the step (1) was 100%.

(Process (2))
While the reaction solution was continuously stirred at -30°C, BA292g as a monomer was added at a rate of 5g/min. The reaction solution was sampled immediately after the addition of the monomer.
The BA consumption rate in the step (2) was 100%.

(Process (3))
While continuously stirring the reaction solution at -30°C, 100 g of a mixture of 5.2 g of AMA and 95 g of MMA as a monomer was added all at once, and the temperature was raised to 25°C. The reaction solution was sampled 300 minutes after the addition of the above mixture.
The consumption rate of AMA and MMA in the step (3) was 100%.

(Process (4))
While continuing to stir the reaction solution at 25° C., 40 g of methanol was added to stop the anionic polymerization, and the methacrylic polymer block (a1)-acrylic polymer block (b)-methacrylic polymer block (a1) was added. (Meth)acrylic block copolymer (hereinafter referred to as "(meth)acrylic block copolymer (I-3)"), which is a triblock copolymer in which (a1-b-a1) of (3) is bonded in that order. A solution containing was obtained. The (meth)acrylic block copolymer (I-3) sampled from this solution had an Mw of 54,200 and an Mw/Mn of 1.08. The content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I-3) was 45% by mass.

(Process (5))
Then, the obtained solution was poured into 5,000 g of methanol to deposit an oily precipitate. The oily precipitate was collected and then dried to obtain 420 g of a (meth)acrylic block copolymer.

[Synthesis Example 4: Synthesis of (meth)acrylic copolymer (II-1)]
(Process (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and replaced with nitrogen, N,N,N′,N″,N″-pentamethyldiethylenetriamine was added as a Lewis base while stirring the solution in the flask. 2.1 g and 19 g of a toluene solution containing 26 mass% of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum as an organoaluminum compound were sequentially added, and then cooled to -30°C. To this was added 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound, and then 11 g of a mixture of 3.2 g of AMA and 7.9 g of MMA as a monomer was added all at once to start anionic polymerization. did. Subsequently, the reaction solution was stirred at −30° C. for 12 hours to sample the reaction solution.
The consumption rate of AMA and MMA in the step (1) was 100%.

(Process (2))
Subsequently, 114 g of 2-MEA as a monomer was added at a rate of 5 g/min while stirring the reaction solution at -30°C. The reaction solution was sampled immediately after the addition of the monomer.
The consumption rate of 2-MEA in the step (2) was 100%.

(Process (3))
While continuously stirring the reaction solution at -30°C, 3.5 g of MMA as a monomer was added all at once, and then the temperature was raised to 25°C. The reaction solution was sampled 300 minutes after the addition of the above monomers.
The consumption rate of MMA in the step (3) was 100%.

(Process (4))
While continuing to stir the reaction solution at 25° C., 40 g of methanol was added to terminate the anionic polymerization, and a (meth)acrylic copolymer (hereinafter, “(meth)acrylic copolymer (II-3)” was added. Referred to as ). The (meth)acrylic copolymer (II-1) sampled from this solution had an Mw of 16,500 and an Mw/Mn of 1.07. The content of the methacrylic polymer block (a2) in the (meth)acrylic copolymer (II-1) was 13% by mass. Furthermore, the content of the 2-MEA unit in the (meth)acrylic copolymer (II-1) was 87 mol %.

(Process (5))
Then, the obtained solution was poured into 5,000 g of methanol to deposit an oily precipitate. After collecting the oily precipitate, it was dried to obtain 420 g of (meth)acrylic block copolymer.

[Synthesis Example 5: Synthesis of (meth)acrylic copolymer (II-2)]
GA (11.5 g) and 2-MEA (489 g) were solution polymerized in methyl isobutyl ketone according to a conventional method to synthesize a GA-derived epoxy group-containing (meth)acrylic copolymer. The (meth)acrylic copolymer having an acryloyl group is formed by the reaction of the epoxy group of the obtained (meth)acrylic copolymer with acrylic acid (hereinafter, referred to as “(meth)acrylic copolymer (II-2 )”). One equivalent of acrylic acid was used for the reaction based on one equivalent of GA used for the polymerization reaction. The obtained (meth)acrylic copolymer (II-2) had Mw of 22,400 and Mw/Mn of 2.08. The content of the 2-MEA unit in the (meth)acrylic copolymer (II-2) was 98 mol%.

[Example 1]
2.5 g of (meth)acrylic block copolymer (I-1), 7.5 g of (meth)acrylic copolymer (II-1) and pentaerythritol tetrakis(3-mercaptobutyrate) (III-1) ) 0.2g was melt|dissolved and the active energy ray curable composition of 10.2g was obtained.
The physical properties of the obtained active energy ray-curable composition were measured and evaluated by the methods described above. The results are shown in Table 1.

[Examples 2 to 6, Comparative Examples 1 to 4]
(Meth)acrylic block copolymer (I), (meth)acrylic copolymer (II), pentaerythritol tetrakis(3-mercaptobutyrate) (III-1), pentaerythritol tetrakis(3-mercaptopropio) (III-2), pentaerythritol triallyl ether, 4-hydroxybutyl acrylate, and isodecyl acrylate were used in the same manner as in Example 1 except that the amounts used were as shown in Table 1. A sex composition was obtained.
The physical properties of the obtained active energy ray-curable composition were measured and evaluated by the methods described above. The results are shown in Table 1.

From the results shown in Table 1, in Examples 1 to 6 satisfying the requirements of the present invention, at 25° C., there is no spinnability and it is gel-like, but at 80° C., the viscosity is 2000 Pa·s or less and it is liquid, It can be seen that the state changes between liquid and gel between low temperature and low temperature. Furthermore, it can be seen that the oil resistance is excellent because the weight change rate and the volume change rate are small in the oil resistance evaluation.
On the other hand, of the methacrylic polymer block (a1) based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) contained in the active energy ray-curable composition. In Comparative Example 1 in which the content is less than 5% by mass, no gel is formed at 25° C., and in Comparative Example 2 in which the content exceeds 35% by mass, the (meth)acrylic block copolymer (I) The solid content remained. Further, in Comparative Example 3 in which 4-hydroxybutyl acrylate was used instead of the (meth)acrylic copolymer (II), a gel was not formed at 25° C., and in Comparative Example 4 in which isodecyl acrylate was used, Although it shows a gel at 25°C, it is found that the oil resistance is inferior because the weight and volume change rates increase in the oil resistance evaluation.

Claims (6)

A methacrylic polymer block (a1) having an active energy ray-curable group containing a partial structure (1) represented by the following general formula (1), and an acrylic polymer block (a1) having no active energy ray-curable group ( b) and a (meth)acrylic block copolymer (I) having a weight average molecular weight of 20,000 or more,
The weight average molecular weight is 3,000 or more and smaller than the weight average molecular weight of the (meth)acrylic block copolymer (I), and the active energy ray-curable group of the (meth)acrylic block copolymer (I) is used. A (meth)acrylic copolymer (II) having 70% by mole or more of the same monomer unit as the acrylic polymer block (b) which does not have a radical polymerizable unsaturated bond. ), and an active energy ray-curable composition containing a compound (III) having two or more mercapto groups in one molecule,
Based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) contained in the active energy ray-curable composition, the methacrylic polymer block (a1) ) Content is 5 to 35% by mass,
Active energy ray curable composition.

(In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and W represents a saturated hydrocarbon group having 1 to 10 carbon atoms.) The (meth)acrylic copolymer (II) contains a methacrylic polymer block (a2) having an active energy ray-curable group including the partial structure (1) represented by the general formula (1). The active energy ray-curable composition according to claim 1. The methacrylic polymer block (a1) and the methacrylic polymer block (a2) are based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II). The active energy ray-curable composition according to claim 2, wherein the total content thereof is 7 to 35% by mass. The active energy ray curing according to any one of claims 1 to 3, wherein the content of the methacrylic polymer block (a1) in the (meth)acrylic block copolymer (I) is 15 to 80% by mass. Sex composition. The mass ratio (I)/(II) of the (meth)acrylic block copolymer (I) and the (meth)acrylic copolymer (II) is 10/90 to 50/50. The active energy ray-curable composition according to any one of 1 to 4. The mercapto group contained in the compound (III) has a mercapto group of 0. 0 relative to the carbon-carbon double bond of the (meth) acrylic block copolymer (I) and the (meth) acrylic block copolymer (II). The active energy ray-curable composition according to any one of claims 1 to 5, which is contained in an amount of 1 to 5.0 molar equivalents.