JP2020007503A - Active energy ray-curable composition - Google Patents

Abstract

To provide an active energy ray-curable composition whose state can be changed to a liquid state and a gel state between a high temperature and a low temperature and whose cured product after active energy ray irradiation has excellent oil resistance.SOLUTION: The active energy ray-curable composition contains: a (meth)acrylic block copolymer (I) which contains a methacrylic polymer block (a) having an α,β-unsaturated double bond structure in an ester moiety and an acrylic polymer block (b) having no active energy ray-curable group and which has an Mw of 20,000 or more; and a (meth)acrylic monomer (II) having a polyoxyalkylene structure. The content of the polymer block (a) is 15-50 mass% based on the total mass of the (meth)acrylic block copolymer (I) and the (meth)acrylic monomer (II).SELECTED DRAWING: None

Description

  The present invention relates to a polymer composition having active energy ray 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 into a liquid state and a gel state.

  Active energy ray-curable compositions that are cured by irradiating active energy rays such as ultraviolet rays and electron beams are known, and include adhesives, adhesives, sealing materials, paints, inks, coating materials, optical molding materials, and the like. Used for applications.

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

  Among the above applications, there are adhesives for fixing components of optical devices such as a liquid crystal display and an optical lens, and components of electronic devices such as electronic paper and batteries, and in some cases, the fixing. Need to be released. Patent Literature 1 discloses that a specific block copolymer compound and a medium are compatible to form a compatible composition, and the state changes between a high temperature and a low temperature to a liquid state and a gel state. It is described that the members can be easily applied underneath, become gel-like at a low temperature, and can be bonded to each other, and when heated again, become liquid and can easily release the fixing between the members.

JP 2017-066368 A

  Although the compatible composition described in Patent Document 1 includes a description of a compound to which reactivity is further imparted and a description of a reactive medium such as a (meth) acrylate-based monomer, it is described in Patent Document 1. In the case of the compatible composition, the cured product after irradiation with active energy rays had poor oil resistance.

  Thus, an object of the present invention is to easily apply a member to a member at a high temperature, to form a gel at a low temperature and to bond the members to each other, and to raise the temperature to a liquid again to easily release the fixing between the members. In order to provide an active energy ray-curable composition, the state of which can change between a high temperature and a low temperature into a liquid state and a gel state, and a cured product after irradiation with active energy rays has excellent oil resistance. That is.

  The present inventors have conducted intensive studies to achieve the above object, and as a result, by using a specific (meth) acrylic block copolymer and a (meth) acrylic monomer having a specific structure, The state can be changed from liquid to gel between high and low temperatures, it can be easily applied to members at high temperatures, becomes gel at low temperatures, and can adhere to each other. An active energy ray-curable composition that can easily release the fixation between members as well as an active energy ray-curable composition that is excellent in oil resistance as a cured product after active energy ray irradiation is obtained. The present invention was completed by further study based on the finding and the findings.

The present invention relates to the following.
[1] A methacrylic polymer block (a) having an active energy ray-curable group containing a partial structure (1) represented by the following general formula (1), and an acrylic polymer having no active energy ray-curable group A (meth) acrylic block copolymer (I) containing a coalesced block (b) and having a weight average molecular weight of 20,000 or more, and a (meth) acrylic monomer (II) having a polyoxyalkylene structure An active energy ray-curable composition containing
The methacrylic polymer block (a) is based on the total mass of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) contained in the active energy ray-curable composition. ) Is 15 to 50% 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.)
[2] The active energy ray-curable composition according to [1], wherein the content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I) is 17 to 80% by mass. object.
[3] The mass ratio (I) / (II) of the (meth) acrylic block copolymer (I) to the (meth) acrylic monomer (II) is 40/60 to 80/20. The active energy ray-curable composition according to [1] or [2].
[4] The active energy ray-curable composition according to any one of [1] to [3], wherein the number of repeating oxyalkylene units in the (meth) acrylic monomer (II) is 3 to 100. .

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

Hereinafter, the present invention will be described in detail.
In this specification, “(meth) acryl” means a general term for “methacryl” and “acryl”, and “(meth) allyl” means a general term for “methallyl” and “allyl”. “(Meth) acryloyl” means a generic term for “methacryloyl” and “acryloyl”, and “(meth) acrylate” means a generic term for “methacrylate” and “acrylate”.

  The active energy ray-curable composition of the present invention comprises a methacrylic polymer block (a) having an active energy ray-curable group having a partial structure (1) and an acrylic polymer having no active energy ray-curable group. A (meth) acrylic block copolymer (I) containing a coalesced block (b) and having a weight average molecular weight of 20,000 or more, and a (meth) acrylic monomer (II) having a polyoxyalkylene structure ).

<(Meth) acrylic block copolymer (I)>
The (meth) acrylic block copolymer (I) of the present invention has a methacrylic polymer block (a) having an active energy ray-curable group containing a partial structure (1) and an active energy ray-curable group. And an 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. Light rays include far ultraviolet rays, ultraviolet rays (UV), near ultraviolet rays, visible rays, infrared rays, etc., electromagnetic waves include X-rays and γ-rays, and particle rays include electron rays (EB) and proton rays (α). Wire), neutron beam and the like. Among these active energy rays, ultraviolet rays and electron beams are preferable, and ultraviolet rays are more preferable, from the viewpoints of curing speed, availability of an irradiation device, and price.

  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.

In the general formula (1), examples of the hydrocarbon group having 1 to 20 carbon atoms represented by R 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- Butyl, t-butyl, 2-methylbutyl, 3-methylbutyl, 2-ethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, n-pentyl, neopentyl, n-hexyl Alkyl groups such as a group, 2-methylpentyl group, 3-methylpentyl group and n-decyl group; cycloalkyl groups such as a cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group; aryl groups such as a phenyl group and a naphthyl group An aralkyl group such as a benzyl group and a phenylethyl group. R ¹ is preferably a hydrocarbon group having 1 to 6 carbon atoms, more preferably a hydrocarbon group having 1 to 2 carbon atoms, and still more preferably a methyl group, from the viewpoint of active energy ray curability.

  In the above 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, is preferably linear or branched, and is more preferably linear. Examples of W include ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, Pentane-1,5-diyl group, hexane-1,6-diyl group, cyclohexane-1,4-diyl group and the like. W is preferably a saturated hydrocarbon group having 2 to 6 carbon atoms, more preferably a saturated hydrocarbon group having 2 carbon atoms, and particularly preferably an ethane-1,2-diyl group, from the viewpoint of active energy ray curability.

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

  The ratio of the number of moles of the partial structure (1) to the number of moles of all monomer units constituting the methacrylic polymer block (a) is 0.01% by mole or more from the viewpoint of active energy ray curability. It is preferably at least 0.05 mol%, more preferably at least 0.3 mol%, particularly preferably at least 1.0 mol%. Further, it is preferably at most 50 mol%, more preferably at most 40 mol%, further preferably at most 30 mol%, further preferably at most 20 mol%, furthermore preferably at least 10 mol%. %.

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

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

In the general formula (2), the definition and description of each of R ¹ and W are the same as those in the general formula (1), and the description thereof will not be repeated.

  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 Ethyl-6-heptenyl, 7-ethyl-7-octenyl methacrylate, and the like, among which, from the viewpoint of active energy ray curability, allyl methacrylate, 3-methyl-3-butenyl methacrylate, 4-methacrylic acid Methyl-4-pentenyl, 5-methyl-5-hexenyl methacrylate, 6-methacrylic acid -6-heptenyl, methacrylic acid 7-methyl-7-octenyl, and more preferably methacrylic acid 3-methyl-3-butenyl. In addition, 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 (a) is determined by active energy ray curing. From the viewpoint of properties, it is preferably at least 0.01 mol%, more preferably at least 0.05 mol%, further preferably at least 0.3 mol%, and more preferably at least 1.0 mol%. It is particularly preferred that there is. 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, or even 10 mol% or less.

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

  Examples of the monofunctional methacrylate include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate Methacrylates having no functional group such as isobornyl methacrylate, dodecyl methacrylate, 2-methoxyethyl methacrylate, phenyl methacrylate, naphthyl methacrylate; 2-hydroxyethyl methacrylate, 2-hydroxybutyl methacrylate, methacrylic acid Trimethoxysilylpropyl acrylate, 2-aminoethyl methacrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, 2- (trimethylsilyl methacrylate) Oxy) ethyl, 3- (trimethylsilyloxy) propyl methacrylate, glycidyl methacrylate, γ- (methacryloyloxypropyl) trimethoxysilane, ethylene oxide adduct of methacrylic acid, trifluoromethylmethyl methacrylate, 2-trifluoro methacrylate Methyl ethyl, 2-perfluoroethyl methacrylate, 2-perfluoroethyl methacrylate-2-perfluorobutyl ethyl, 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, methacryl 2-perfluoromethyl-2-perfluoroethylmethyl acid, 2-perfluorohexylethyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluorohexyl methacrylate Examples include methacrylates having a functional group such as xadecylethyl. Among these, alkyl methacrylate 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 preferable, and methyl methacrylate is more preferable.

  The ratio of the number of moles of the monomer unit derived from the monofunctional methacrylate ester (for example, methyl methacrylate) to the number of moles of all the monomer units of the methacrylic polymer block (a) is represented by an active energy ray. From the viewpoint of curability, the content is preferably 99.99 mol% or less, more preferably 99.95 mol% or less, further preferably 99.7 mol% or less, and more preferably 99 mol% or less. Is particularly preferable, and it is preferably at least 10 mol%, more preferably at least 30 mol%, even more preferably at least 50 mol%. The ratio of the number of moles of the monomer unit derived from the monofunctional methacrylic ester is determined when the methacrylic polymer block (a) is contained in the (meth) acrylic block copolymer (I) in plurals. Is preferably 99.99 mol% or less, more preferably 99.95 mol% or less, even more preferably 99.7 mol% or less, and more preferably 99 mol% in each polymer block. It is particularly preferred that the content is not more than 10 mol%, more preferably not less than 30 mol%, and still more preferably not less than 50 mol%.

  When the methacrylic polymer block (a) is formed from a monofunctional methacrylic acid ester and a monomer containing the methacrylic acid ester represented by the general formula (2), the methacrylic polymer block (a) The ratio of the number of moles of the monomer unit derived from the monofunctional methacrylate to the number of moles of all the monomer units and the mole of the monomer unit derived from the methacrylate represented by the general formula (2) The total proportion of the proportions occupied by the numbers is preferably at least 30 mol%, more preferably at least 70 mol%, further preferably at least 90 mol%, particularly preferably at least 95 mol%. Preferably, it may be 100 mol%. Further, when the methacrylic polymer block (a) is formed from a monomer containing methyl methacrylate and a methacrylic ester represented by the general formula (2), the methacrylic polymer block (a) The ratio of the number of moles of monomer units derived from methyl methacrylate to the number of moles of all monomer units and the number of moles of monomer units derived from methacrylic ester represented by the above general formula (2) The total ratio of the occupying ratio is preferably at least 30 mol%, more preferably at least 70 mol%, further preferably at least 90 mol%, particularly preferably at least 95 mol%, It may be 100 mol%. When the methacrylic polymer block (a) includes a plurality of (meth) acrylic block copolymers (I), the content is preferably in the above-mentioned preferred range for each polymer block. Is a more preferable range, which is a preferable embodiment.

  The methacrylic polymer block (a) may be any other than the methacrylic ester represented by the general formula (2) and the monofunctional methacrylic ester having one methacryloyl group as long as the effects of the present invention are not impaired. It may include a monomer unit derived from a monomer.

  Examples of the other monomers 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-acrylate Dimethylaminoethyl, N, N-diethylaminoethyl acrylate, phenyl acrylate, naphthyl acrylate, 2- (trimethylsilyloxy) ethyl acrylate, 3- (trimethylsilyloxy) propyl acrylate, glycidyl acrylate, γ- ( (Acryloyloxypropyl) trimethoxysilane, ethylene oxide adduct of acrylic acid, trifluoromethylmethyl acrylate, 2-trifluoromethylethyl acrylate, 2-perfluoroethylethyl acrylate, 2-perfluoroethyl acrylate 2-perfluorobutylethyl, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethylmethyl acrylate, 2-perfluoromethyl acrylate-2-perfluoroethylmethyl, 2-perfluoroacrylate Acrylic esters such as hexylethyl, 2-perfluorodecylethyl acrylate and 2-perfluorohexadecylethyl acrylate; α-alkoxyacrylic acid such as α-methyl methacrylate and α-ethoxy methacrylate; Steronic acid esters such as methyl crotonate and ethyl crotonate; 3-alkoxyacrylic acid esters such as 3-methoxyacrylic acid ester; N-isopropyl (meth) acrylamide; Nt-butyl (meth) acrylamide; (Meth) acrylamides such as N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide; methyl 2-phenylacrylate, ethyl 2-phenylacrylate, n-butyl 2-bromoacrylate, 2-bromo Examples include methyl methyl acrylate, ethyl 2-bromomethyl acrylate, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, and ethyl isopropenyl ketone.

  One of these other monomers may be used alone, or two or more thereof may be used in combination.

  The ratio of the mole number of the monomer unit derived from the other monomer to the mole number of all the monomer units constituting the methacrylic polymer block (a) is 10 mol% from the viewpoint of curability. Or less, more preferably 5 mol% or less. 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 methacrylic polymer block (a) is represented by the methacrylic polymer block (a). ) Is contained in the (meth) acrylic block copolymer (I) in one embodiment, in each of the polymer blocks, preferably 10 mol% or less, more preferably 5 mol% or less. It is.

  The content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I) is preferably 80% by mass or less, more preferably 70% by mass or less. It is preferably at least 30 mass%, more preferably at least 30 mass%. When the content is equal to or more than the above lower limit, it tends to become a gel at a low temperature, and when the content is equal to or less than the above upper limit, there is a tendency that the viscosity is reduced at a high temperature.

  The glass transition temperature (Tg) of the methacrylic polymer block (a) is preferably 90 ° C. or higher, more preferably 95 ° C. or higher, and further preferably 100 ° C. or higher. Further, the temperature is preferably 160 ° C. or lower, more preferably 150 ° C. or lower. The Tg of the methacrylic polymer block (a) can be controlled by the type of the monomer forming the methacrylic polymer block (a), the polymerization method, and the like. When the Tg of the methacrylic polymer block (a) falls within this range, the handleability and heat resistance of the (meth) acrylic block copolymer (I) obtained are improved. The Tg in the present specification refers to a polymer observed in a curve obtained by performing a DSC measurement on a polymer block or a (meth) acrylic block copolymer (I) at a temperature rise rate of 10 ° C./min. Extrapolation start temperature (Tgi) of the transition region of the block.

  The weight average molecular weight of the methacrylic polymer block (a) is 500 or more and 40,000 or less from the viewpoint of handleability, fluidity, mechanical properties, and the like of the (meth) acrylic block copolymer (I) obtained. It is more preferable that it is 1,000 or more and 30,000 or less. When a plurality of the methacrylic polymer blocks (a) are included in the (meth) acrylic block copolymer (I), the weight average molecular weight of each polymer block is in the above-mentioned preferred range, preferably in the more preferred range. Is a preferred embodiment. In this specification, the number average molecular weight (Mn), the weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) are calculated from the values in terms of standard polystyrene obtained by gel permeation chromatography (GPC) measurement and the values thereof. This 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 this specification, the term "active energy ray-curable group" means a functional group that exhibits polymerizability upon irradiation with the active energy ray. Examples of the active energy ray-curable group include a (meth) acryloyl group (may be a (meth) acryloyloxy group), a vinyl group, a (meth) allyl group, a vinyloxy group, a 1,3-dienyl group, and a styryl. ethylenic double bond (in particular the general formula CH 2 ₌ CR- (wherein, R ethylenic double bond represented by an alkyl group or a hydrogen atom)), such as a group functional group having, epoxy group, oxetanyl group, a 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 include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, acrylic Isobornyl acrylate, lauryl acrylate, dodecyl acrylate, trimethoxysilyl 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, 2- (2-ethoxyethoxy) ethyl acrylate, methoxytriethylene glycol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) acrylate And acrylic acid (3-ethyloxetane-3-yl). Among these, n-butyl acrylate, tetrahydrofurfuryl acrylate, 2- (2-ethoxyethoxy) ethyl acrylate, and methoxytriethylene glycol acrylate from the viewpoint of lowering the viscosity when liquid at high temperatures 2-methoxyethyl acrylate is preferred, 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, tetrahydrofur acrylate having high hydrophilicity is preferred. Furyl, 2- (2-ethoxyethoxy) ethyl acrylate, methoxytriethylene glycol acrylate, and 2-methoxyethyl acrylate are more preferred, and 2-methoxyethyl acrylate is even more preferred. One of these acrylic acid esters may be used alone, or two or more thereof may be used in combination.

  As the solubility parameter (SP value) of the acrylate, the compatibility with the (meth) acrylic monomer (II) and the value after irradiating the active energy ray-curable composition of the present invention with the active energy ray are used. From the viewpoint of the oil resistance of the cured product, it is preferably 8.0 or more, more preferably 8.5 or more, and even 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 more preferable. In addition, the solubility parameter in this specification is a value obtained 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 based on the number of moles of all the monomer units of the acrylic polymer block (b), The content 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 a plurality of the acrylic polymer blocks (b) are contained in the (meth) acrylic block copolymer (I), the content of the monomer unit derived from the acrylate ester is determined by the content of each polymer. In each of the blocks, it is preferably at least 90 mol%, more preferably at least 95 mol%, and may be at least 100 mol%.

  The acrylic polymer block (b) may contain a monomer unit derived from another monomer in addition to the acrylate ester as long as the effects of the present invention are not impaired.

  Examples of the other monomers include the above-mentioned methacrylates; α-alkoxyacrylates such as α-methyl methacrylate and α-ethoxy acrylate; crotonic acids such as methyl crotonate and ethyl crotonate Ester; 3-alkoxyacrylic acid ester such as 3-methoxyacrylic acid ester; acrylamide such as N-isopropylacrylamide, Nt-butylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide; N-isopropylmethacrylic Methacrylamides such as amide, Nt-butylmethacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide; methyl 2-phenylacrylate, ethyl 2-phenylacrylate, 2-bromoacrylic acid n − Le, 2-bromomethyl methyl acrylate, 2-bromo-methyl acrylate, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, ethyl isopropenyl ketone.

  One of these other monomers may be used alone, or two or more thereof may be used in combination.

  The ratio of the mole number of the monomer unit derived from the other monomer to the mole number of all the monomer units constituting the acrylic polymer block (b) is preferably 10 mol% or less. More preferably, it is 5 mol% or less. The ratio of the mole number of the monomer unit derived from the other monomer to the mole number of all the monomer units constituting the acrylic polymer block (b) is as follows. ) Is contained in the (meth) acrylic block copolymer (I) in one embodiment, in each of the polymer blocks, preferably 10 mol% or less, more preferably 5 mol% or less. It is.

  The content of the acrylic polymer block (b) in the (meth) acrylic block copolymer (I) is preferably at least 20% by mass, more preferably at least 30% by mass, and 83 It is preferably at most 70 mass%, more preferably at most 70 mass%. When the content is equal to or more than the above lower limit, the viscosity tends to be excellent when the liquid becomes a liquid at a high temperature, and when the content is less than the above upper limit, a gel tends to be formed at a 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 temperatures.

  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 (meth) acrylic block copolymer (I) obtained. And more preferably 10,000 or more and 200,000 or less.

  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 a low temperature. Further, it is preferably not more than 400,000, more preferably not more than 300,000. When the weight average molecular weight of the (meth) acrylic block copolymer (I) is equal to or less than the above upper limit, fluidity tends to be excellent when it becomes liquid at high temperatures.

  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 1.01. The range of 1.80 is more preferred, and the range of 1.01 to 1.50 is even more preferred.

  The (meth) acrylic block copolymer (I) is a block copolymer having at least one methacrylic polymer block (a) and at least one acrylic polymer block (b). There is no particular limitation on the number and the bonding order of the coalesced blocks, but from the viewpoint of active energy ray curability, the methacrylic polymer block (a) has at least one terminal of the (meth) acrylic block copolymer (I). It is preferably formed, and from the viewpoint of easy production of the (meth) acrylic block copolymer (I), it is more preferably a linear polymer, and one methacrylic polymer block (a) Or a diblock copolymer in which one acrylic polymer block (b) is bonded, or a methacrylic polymer block at both ends of one acrylic polymer block (b) a) tri-block copolymer each one is attached respectively are more preferred.

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

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

  As the living anionic polymerization method, a method of living polymerization using an organic rare earth metal complex as a polymerization initiator (see Japanese Patent Application Laid-Open No. Hei 6-93060), a method of using an organic alkali metal compound as a polymerization initiator, Living anion polymerization in the presence of a salt such as a salt (see Japanese Patent Application Laid-Open No. 5-507737), and living anion polymerization in which an organic alkali metal compound is used as a polymerization initiator in the presence of an organic aluminum compound. (See, for example, JP-A-11-335432 and WO 2013/141105). Among these living anionic polymerization methods, from the viewpoint that the (meth) acrylic block copolymer (I) can be polymerized directly and efficiently, an organic alkali metal compound is used as a polymerization initiator in the presence of an organic aluminum compound. A method of anionic polymerization is preferable, and a method of living anionic 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 to be used can be determined by the ratio to the amount of the monomer to be used, according to the number average molecular weight of the target (meth) acrylic block copolymer (I).

Examples of the organoaluminum compound include an organoaluminum compound represented by the following general formula (A-1) or (A-2).
AlR ² (R ³ ) (R ⁴ ) (A-1)
(Wherein, 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)
(Wherein, R ⁵ represents an aryloxy group, and R ⁶ and R ⁷ each independently represent 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 independently include, for example, a phenoxy group, a 2-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, And a 7-methoxy-2-naphthoxy group.

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, and 2,2 ′ -Methylenebis (4-methyl-6-t-butylphenol), (R)-(+)-1,1'-bi-2-naphthol, (S)-(-)-1,1'-bi-2- In a compound having two phenolic hydroxyl groups, such as naphthol, a functional group in which the hydrogen atoms of the two phenolic hydroxyl groups have been removed is exemplified.
One or more hydrogen atoms contained in the above aryloxy group and arylenedioxy group may be substituted by a substituent, for example, a methoxy group, an ethoxy group, an isopropoxy group, An alkoxy group such as a t-butoxy group; a halogen atom such as a chlorine atom and a 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 an n-propyl Groups, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, 2-methylbutyl group, 3-methylbutyl group, n-octyl group, alkyl group such as 2-ethylhexyl group; cyclohexyl group And the monovalent aromatic hydrocarbon group includes, for example, an aryl group such as a phenyl group; an aralkyl group such as a benzyl group; and the alkoxy group includes, for example, 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 dimethylamino group, a diethylamino group, and a diisopropylamino group. A dialkylamino group such as a mino group; a bis (trimethylsilyl) amino group; 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 by 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; and a halogen atom such as a chlorine atom and a bromine atom.

  Examples of the organoaluminum compound (A-1) include ethyl bis (2,6-di-t-butyl-4-methylphenoxy) aluminum, ethyl bis (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, Sopropoxy [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, t-butoxybis (2,6-di-tert-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, tris (2,6-diphenylphenoxy) aluminum and the like. Above all, isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum and isobutylbis (2,6) are considered from the viewpoints of polymerization initiation efficiency, living property of the 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, diisobutyl (2 , 6-Di-tert-butyl-4-methylphenoxy) aluminum, diisobutyl (2,6-di-tert-butylphenoxy) aluminum, di-n-octyl (2,6-di-tert-butyl-4-methyl) Phenoxy) aluminum, di-n-octyl (2,6-di-t-butylphenoxy) aluminum and the like. One of these organoaluminum compounds may be used alone, or two or more thereof may be used in combination.

  The amount of the organoaluminum compound to be used can be appropriately selected according to the type of the solvent, various other polymerization conditions, and the like. It is preferably used in a range of 0.0 mol, more preferably in a range of 1.1 to 5.0 mol, and still more preferably in a range of 1.2 to 4.0 mol. If the amount of the organoaluminum compound exceeds 10.0 mol per 1 mol of the organolithium compound, it tends to be disadvantageous in terms of economy, 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 a molecule or a non-cyclic ether having one or more ether bonds in a molecule from the viewpoint of high polymerization initiation efficiency and living property of a polymerization terminal anion. Is preferred. Examples of the cyclic ether having two or more ether bonds in a molecule include crown ethers such as 12-crown-4, 15-crown-5, and 18-crown-6. Examples of the acyclic 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, , 3-diphenoxypropane, 1,4-dimethoxybutane, 1,4-diethoxybutane, Acyclic diethers such as 1,4-diisopropoxybutane, 1,4-dibutoxybutane and 1,4-diphenoxybutane; 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 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, acyclic polyethers such as tetramethylammonium butylene glycol diethyl ether. Among them, acyclic ethers having one or two ether bonds in the molecule are preferable, and diethyl ether or 1,2-dimethoxyethane is more preferable, from the viewpoint of suppression of side reactions and availability.

  Examples of the compound having a tertiary amine structure in the molecule used as the Lewis base include a tertiary polyamine. The tertiary polyamine means a compound having two or more tertiary amine structures in a 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 and 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. That.

  Further, a compound having one or more ether bonds and one or more tertiary amine structures 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 to be used is preferably in the range of 0.3 to 5.0 mol, and more preferably 0.5 to 5.0 mol, per 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 even more preferably in the range of 1.0 to 2.0 mol. If the amount of the Lewis base is more than 5.0 moles per 1 mole of the organolithium compound, the economy tends to be disadvantageous, and if it is less than 0.3 mole, the polymerization initiation efficiency tends to decrease.

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

  The living anionic polymerization is preferably performed in the presence of an organic solvent from the viewpoint of controlling the temperature and making the inside of the system uniform so that the polymerization proceeds smoothly. Examples of the organic solvent include hydrocarbons such as toluene, xylene, cyclohexane and methylcyclohexane; chloroform, chloride, and the like, from the viewpoints of safety, separation from water in washing the reaction solution after polymerization with water, and ease of recovery and reuse. Halogenated hydrocarbons such as methylene and carbon tetrachloride; esters such as dimethyl phthalate are preferred. One of these organic solvents may be used alone, or two or more thereof may be used in combination. The organic solvent is preferably subjected to a drying treatment and degassed in advance in the presence of an inert gas, from the viewpoint of allowing the polymerization to proceed smoothly.

  In addition, in the living anionic polymerization, other additives may be added to the reaction system as needed. Examples of the other additives include inorganic salts such as lithium chloride; metal alkoxides such as lithium methoxyethoxy ethoxide and potassium t-butoxide; tetraethylammonium chloride and tetraethylphosphonium bromide.

  The living anionic polymerization is preferably performed at -30 to 25 ° C. If the temperature is lower than -30 ° C, the polymerization rate tends to decrease, and the productivity tends to decrease. On the other hand, when 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 properties.

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

  In the living anionic polymerization, as a method of adding an organic lithium compound, an organic aluminum compound, a Lewis base and a monomer to the reaction system, the Lewis base may be brought into contact with the organoaluminum compound before contact with the organolithium compound. It is preferred to add. The organoaluminum compound may be added to the reaction system before the monomer, or may be added at the same time. When the organoaluminum compound is added to the reaction system simultaneously with the monomer, the organoaluminum compound may be added after being separately mixed with the monomer.

  The living anionic polymerization can be stopped by adding a polymerization terminator such as methanol, a methanol solution of acetic acid or hydrochloric acid, or a protic compound such as an aqueous solution of acetic acid or hydrochloric acid to the reaction solution. Usually, the amount of the polymerization terminator 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 solution after the termination of the living anionic polymerization, a known method can be adopted. For example, a method in which the reaction solution is poured into a poor solvent of the (meth) acrylic block copolymer (I) to cause precipitation, or the (meth) acrylic block copolymer (I) is distilled off by removing an organic solvent from the reaction solution. And a method of obtaining the information.

  If the metal component derived from the organolithium compound and the organoaluminum compound remains in the separately obtained (meth) acrylic block copolymer (I), the (meth) acrylic block copolymer (I) In some cases, a decrease in physical properties, poor transparency and the like may occur. Therefore, it is preferable to remove the metal components derived from the organolithium compound and the organoaluminum compound after termination of the anionic polymerization. As a method for removing the metal component, a washing treatment using an acidic aqueous solution, an adsorption treatment using an adsorbent such as an ion exchange resin, celite, activated carbon, and the like are 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 and the like can be used.

  In the production of the (meth) acrylic block copolymer (I), as a method for introducing the partial structure (1), a monomer containing a methacrylic ester represented by the general formula (2) is polymerized. In addition to the method of forming the methacrylic polymer block (a) by the above, after forming a polymer block including a partial structure (hereinafter, referred to as “precursor structure”) which is a precursor of the partial structure (1), There is also a method of converting the precursor structure into the partial structure (1). The polymer block containing the precursor structure is obtained by polymerizing a monomer containing a polymerizable functional group and a compound containing the 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. The precursor structure includes 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, and a thiol group protected by a protecting group. And an isocyanate group.

  A polymer block containing a hydroxyl group as a precursor structure is prepared by reacting a methacrylic polymer block (a) with a compound having a partial structure (1) and a compound having a partial structure (carboxylic acid, ester, carbonyl halide, etc.) capable of reacting with a hydroxyl group. ) Can be formed. Further, a polymer block containing a hydroxyl group protected by a protecting group as a precursor structure can similarly form a methacrylic polymer block (a) after removing the protecting 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 the amino group (such as carboxylic acid, carboxylic anhydride, ester, carbonyl halide, aldehyde group, and isocyanate group). The methacrylic polymer block (a) can be formed by reacting with a compound. Further, a polymer block containing an amino group protected by a protective group as a precursor structure can form a methacrylic polymer block (a) in the same manner after removing the protective group to make an amino group.

  The polymer block containing a thiol group as the precursor structure includes a partial structure (1) and a partial structure capable of reacting with the thiol group (carboxylic acid, carboxylic anhydride, ester, carbonyl halide, isocyanate group, carbon-carbon double bond) ) To form a methacrylic polymer block (a). Further, a polymer block containing a thiol group protected by a protective group as a precursor structure can form a methacrylic polymer block (a) in the same manner after removing the protective group to form a thiol group.

  A polymer block containing an isocyanate group as a precursor structure can form a methacrylic polymer block (a) by reacting with a compound having a partial structure (1) and a partial structure (such as a hydroxyl group) that can react with the isocyanate group. .

  In the production of the (meth) acrylic block copolymer (I), as a method of forming the methacrylic polymer block (a), from the viewpoint that the partial structure (1) can be easily directly introduced, the above general formula (2) )), A method of polymerizing a monomer containing a methacrylic acid ester, typically a method of living anionic polymerization is preferred.

<(Meth) acrylic monomer (II) having polyoxyalkylene structure>
The active energy ray-curable composition of the present invention contains a (meth) acrylic monomer (II) having a polyoxyalkylene structure.

  Examples of the polyoxyalkylene structure of the (meth) acrylic monomer (II) include a polyoxyethylene structure, a polyoxypropylene structure, a polyoxybutylene structure, and the like. An ethylene structure is preferred.

  The (meth) acrylic monomer (II) preferably has a repeating unit number of the oxyalkylene unit of 100 or less, more preferably 30 or less, from the viewpoint of lowering the viscosity when it becomes a liquid at a high temperature. Is more preferable, it is still more preferably 20 or less, and particularly preferably 15 or less. Further, it is preferably 3 or more, and more preferably 4 or more.

  The number average molecular weight (Mn) of the (meth) acrylic monomer (II) is preferably 150 or more, more preferably 200 or more, and even more preferably 250 or more, from the viewpoint of flexibility and strength of the cured product. In addition, from the viewpoint of lowering the viscosity when it becomes liquid at a high temperature, it is preferably 5,000 or less, more preferably 3,000 or less, and still more preferably 1,500 or less.

  The boiling point of the (meth) acrylic monomer (II) is preferably 200 ° C or higher, more preferably 250 ° C or higher, even more preferably 300 ° C or higher, from the viewpoint of storage stability of the active energy ray-curable composition. .

  The solubility parameter (SP value) of the (meth) acrylic monomer (II) is preferably 8.0 or more from the viewpoint of compatibility with the (meth) acrylic block copolymer (I). 5 or more is more preferable, and 9.0 or more is further preferable. Moreover, 13 or less is preferable, 12.5 or less is more preferable, and 12 or less is further more preferable.

  Specific examples of the (meth) acrylic monomer (II) include, for example, di (meth) acrylate having a polyoxyalkylene structure, and mono (meth) acrylate having a polyoxyalkylene structure. In addition, tri- or more functional (meth) acrylic monomers such as ethoxylated glycerin tri (meth) acrylate may be used.

  Examples of the di (meth) acrylate having a polyoxyalkylene structure include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol-polypropylene glycol di (meth) acrylate, and triethylene glycol di (meth) acrylate. Examples include acrylate, tripropylene glycol di (meth) acrylate, and polytetramethylene glycol di (meth) acrylate.

  Examples of the mono (meth) acrylate having a polyoxyalkylene structure include polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, triethylene glycol (meth) acrylate, and tripropylene. Polyalkylene glycol mono (meth) acrylates such as glycol (meth) acrylate; methoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, methoxypolyethylene glycol-polypropylene glycol (meth) acrylate, methoxytriethylene glycol (meth) Acrylate, methoxytripropylene glycol (meth) acrylate, E Bruno alkoxy polyethylene glycol (meth) acrylate, phenoxy polypropylene glycol (meth) acrylate, etc. alkoxy polyalkylene glycol mono A (meth) acrylate such as ethoxydiethylene glycol (meth) acrylate.

  As the (meth) acrylic monomer (II), one type may be used alone, or two or more types may be used in combination. Among these (meth) acrylic monomers (II), acrylic monomers are preferred, diacrylates having a polyoxyalkylene structure, and monoacrylates having a polyoxyalkylene structure are more preferred. Diacrylate having, alkoxy polyalkylene glycol monoacrylate is more preferable, diacrylate having a polyoxyethylene structure, even more preferably alkoxy polyethylene glycol monoacrylate, diacrylate having a polyoxyethylene structure, methoxy polyethylene glycol monoacrylate is particularly preferable. .

  In addition, a commercially available product can also be used as the (meth) acrylic monomer (II). Commercially available products include light acrylate 14EG-A, light acrylate 9EG-A, light acrylate 4EG-A, light acrylate 3EG-A, light acrylate MTG-A, light acrylate EC-A, light acrylate 130A, light Acrylate P-200A, light acrylate PTMGA-250, light acrylate NP-4EA, light acrylate NP-8EA (all manufactured by Kyoeisha Chemical Co., Ltd.), NK ester A-1000, NK ester A-600, NK ester A-400, NK ester A-200, NK ester AM-90G, NK ester AM-130G, NK ester AMP20GY, NK ester APG-700, NK ester A-PTMG-65, NK ester APG-100, K ester APG-200, NK ester APG-400, NK ester A-GLY-9E, NK ester A-GLY-20E (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Bismer MPE550A, Bismer MPE400A, Biscoat MTG, Biscoat # Aronix M-240, Aronix M-111, Aronix M-113, Aronix M-117, Aronix M-101, Aronix M-102 (above, manufactured by Toagosei Co., Ltd.) ), PEG400DA-D, EBECRYL11 (all manufactured by Daicel Ornex), Blemmer AP-400, Blemmer AP-550, Blemmer AP-800, and Blemmer ASE (all manufactured by NOF CORPORATION).

  The (meth) acrylic monomer (II) is produced, for example, by a dehydration condensation reaction between a polyalkylene glycol and (meth) acrylic acid, or a transesterification reaction between a polyalkylene glycol and an alkyl (meth) acrylate. be able to.

  In the active energy ray-curable composition of the present invention, the amount of the methacrylic polymer block (a) is based on the total mass of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II). The content is 15% by mass or more, preferably 18% by mass or more, and more preferably 20% by mass or more. Further, it is 50% by mass or less, preferably 45% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, and particularly preferably 32% by mass or less. preferable. When the content of the methacrylic polymer block (a) is within the above range, an active energy ray-curable composition which is liquid at a high temperature and gels at a low temperature can be obtained.

  The mass ratio (I) / (II) of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) in the active energy ray-curable composition of the present invention is 40. / 60-80 / 20, more preferably 45 / 55-80 / 20, even more preferably 50 / 50-80 / 20, and 50 / 50-75 / 25. Is particularly preferred. When the (meth) acrylic monomer (II) is contained in an amount of 20% by mass or more, the viscosity tends to be low, and when the amount is 60% by mass or less, a gel tends to be formed at low temperature.

  The active energy ray-curable composition of the present invention may contain a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenones (for example, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-2-methyl-1-phenylpropane). -1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methylpropane -1-one, etc.), benzophenones (eg, benzophenone, benzoylbenzoic acid, hydroxybenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, acrylated benzophenone, etc.), Michler's ketones (eg, Michler's ketone, etc.) and benzoins (For example, benzoin, benzoin methyl And benzoin isopropyl ether); sulfur compounds such as tetramethylthiuram monosulfide and thioxanthones (eg, thioxanthone and 2-chlorothioxanthone); acylphosphine oxides (eg, 2,4,6) Phosphorus compounds such as -trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like; titanocenes (for example, bis (η5-2,4-cyclopentadiene-1-) Titanium compounds such as yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium; and azo compounds (eg, azobisisobutylnitrile). Among these, acetophenones and benzophenones are preferred. One of these photopolymerization initiators may be used alone, or two or more thereof may be used in combination.

  The content of the photopolymerization initiator is 0.01 to 10 parts by mass based on 100 parts by mass of the total amount of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II). Is preferable, and 0.05 to 8 parts by mass is more preferable. When it is at least 0.01 part by mass, the curability of the active energy ray-curable composition will be good, and when it is at most 10 parts by mass, 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. Examples of the sensitizer include n-butylamine, di-n-butylamine, tri-n-butylphosphine, allylthiourea, triethylamine, and diethylaminoethyl methacrylate. Among these, diethylaminoethyl methacrylate and triethylamine are preferred.

  When the photopolymerization initiator and the sensitizer are used in combination, the mass ratio of the photopolymerization initiator and the sensitizer is preferably in the range of 10:90 to 90:10, and more preferably in the range of 20:80 to 80:20. Is more preferred.

  The active energy ray-curable composition of the present invention may further contain a solvent. By including a solvent, the viscosity can be adjusted. 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 carbons 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 and amyl acetate; dimethylformamide and the like Amides; alcohols such as methanol, ethanol and propanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone.

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

  The active energy ray-curable composition of the present invention contains the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) of the present invention unless the effects of the present invention are impaired. ), 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 examples thereof include styrene, indene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, pt-butoxystyrene, and p. -Styrene derivatives such as -chloromethylstyrene, p-acetoxystyrene, 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, iso (meth) acrylate Mill, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, (meth) acrylate ) Decyl acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, benzyl (meth) acrylate, (meth) ) Isobornyl acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 4- (meth) acrylate Butylcyclohexyl, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, (meth) Phenoxyethyl acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, 4- (meth) acryloylmorpholine, trimethylolpropanetri (Meth) acrylate, trimethylolpropaneethoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A Both terminal (meth) acrylic acid adducts of glycidyl ether, 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, di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of bisphenol A, addition of ethylene oxide or propylene oxide of hydrogenated bisphenol A Di (meth) acrylate of Diol, Bisphenol A (Meth) acrylic acid derivatives such as epoxy (meth) acrylate and cyclohexanedimethanol di (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether; dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate A) acrylate, ditrimethylolpropanetetra (meth) acrylate, trimethylolpropanepropylene oxide-modified tri (meth) acrylate, trimethylolpropaneethylene oxide-modified tri (meth) acrylate, isocyanuric acid ethylene oxide-modified di (meth) acrylate, ethylene isocyanurate Polyfunctional (meth) acrylates such as oxide-modified tri (meth) acrylate and diglycerin ethylene oxide-modified (meth) acrylate; Epoxy acrylate resins such as sphenol A type epoxy acrylate resin, phenol novolak type epoxy acrylate resin, cresol novolak type epoxy acrylate resin; carboxyl group-modified epoxy acrylate resin; polyol (polyester diol of ethylene glycol and adipic acid, ε-caprolactone Modified polyester diol, 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.). (Meth) acrylate containing hydroxyl group Urethane acrylate resin obtained by reacting with hydroxyoxy (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, pentaerythritol triacrylate, etc.); Resins having introduced groups; polyester acrylate resins; epoxy compounds such as epoxidized soybean oil and epoxy benzyl stearate. Among them, acrylate monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and 4-hydroxybutyl acrylate may be used from the viewpoint of curability and oil resistance of the cured product. preferable. One of these reactive diluents may be used alone, or two or more of them may be used in combination.

  The active energy ray-curable composition of the present invention contains a plasticizer, a tackifier, a softener, an antioxidant, and a filler within a range that does not impair the effects of the present invention and that does not significantly impair the curability. And various additives having no active energy ray-curable group such as a stabilizer, a pigment, and a dye. 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.For example, each component is kneaded with a known mixing or kneading apparatus such as a kneader, an extruder, a mixing roll, and a Banbury mixer. It can be manufactured by mixing at a temperature within the range of 100 to 250 ° C. Moreover, after dissolving each component in a solvent and mixing, the solvent may be removed by distillation.

  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), the acceleration voltage is suitably in the range of 0.1 to 10 MeV, and the irradiation dose is suitably in the range of 1 to 500 kGy.

For UV irradiation, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an LED, or the like that emits light in a 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 20,000 mJ / cm ² , the active energy ray-curable composition may be deteriorated.

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

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

  Examples of the use of the active energy ray-curable composition of the present invention include a curable resin used in the fields of automobiles, home appliances, architecture, civil engineering, sports, displays, optical recording devices, optical devices, semiconductors, batteries, printing, and the like. Adhesives, tapes, films, sheets, mats, sealing materials, sealing materials, sealing materials, coating materials, potting materials, ink, plate materials, vibration damping materials, foams, heat dissipating materials, prepregs, gaskets, packings, etc. .

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

  In addition, BMA, MMA, 2-MEA, and BA in Examples represent 3-methyl-3-butenyl methacrylate, methyl methacrylate, 2-methoxyethyl acrylate, and butyl acrylate, respectively.

In the following Synthesis Examples, Examples and Comparative Examples, the raw materials were dried and purified by a conventional method and used after degassing with nitrogen, and the transfer and supply were performed under a nitrogen atmosphere.
In addition, each evaluation method adopted in the following synthesis examples, examples and comparative examples is shown below.

[Monomer consumption rate]
In the following synthesis examples, the consumption rate of each monomer after polymerization was determined by collecting 0.5 mL of the reaction solution, mixing it in 0.5 mL of methanol, and collecting 0.1 mL from the mixed solution, After dissolving in 0.5 mL of chloroform and performing ¹ H-NMR measurement under the following measurement conditions, a peak derived from a proton directly connected to a carbon-carbon double bond of the (meth) acrylate ester used as a monomer ( It was calculated from the change in the ratio of the integrated value of the peak (chemical shift value: 7.00 to 7.38 ppm) derived from the proton directly connected to the aromatic ring of toluene used as the solvent (chemical shift value: 5.79 to 6.37 ppm). .
⁽¹ H-NMR measurement conditions)
Apparatus: Nuclear magnetic resonance apparatus "JNM-ECX400" manufactured by JEOL Ltd.
Temperature: 25 ° C

[Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn)]
In the following synthesis examples, GPC measurement of the obtained polymer was performed under the following measurement conditions, and values of weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) in terms of standard polystyrene. I asked.
(GPC measurement conditions)
Equipment: GPC equipment "HLC-8220GPC" manufactured by Tosoh Corporation
Separation column: “TSKgel SuperMultipore HZ-M (column diameter = 4.6 mm, column length = 15 cm)” manufactured by Tosoh Corporation (two tubes are connected 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 (a) in (meth) acrylic block copolymer (I)]
The content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I) was determined by adding 0.01 g of the (meth) acrylic block copolymer obtained in the following synthesis example to deuterated chloroform. After dissolving in 0.5 mL, ¹ H-NMR measurement was performed under the following measurement conditions, and peaks (chemical shift values of 2.5 to 5) derived from each ester chain of (meth) acrylate used as a monomer were obtained. 0.0 ppm).
⁽¹ H-NMR measurement conditions)
Apparatus: Nuclear magnetic resonance apparatus "JNM-ECX400" manufactured by JEOL Ltd.
Temperature: 25 ° C

[Method for calculating content of methacrylic polymer block (a) based on total mass of (meth) acrylic block copolymer (I) and (meth) acrylic monomer (II)]
Content of methacrylic polymer block (a) based on the total mass of (meth) acrylic block copolymer (I) and (meth) acrylic monomer (II) contained in the active energy ray-curable composition Is obtained by dissolving 10 mg of the active energy ray-curable composition of the present invention in 0.5 mL of deuterated chloroform and performing ¹ H-NMR measurement under the following measurement conditions to obtain a (meth) acrylate ester used as a monomer. It was calculated from the ratio of the integrated values of peaks (chemical shift values 2.5 to 5.0 ppm) derived from each ester chain.
⁽¹ H-NMR measurement conditions)
Apparatus: Nuclear magnetic resonance apparatus "JNM-ECX400" manufactured by JEOL Ltd.
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 at a measurement temperature of 80 ° C., a measurement gap of 0.05 mm, and a shear rate of 1 (1 / s) using a steady flow viscosity measurement mode as a measurement mode. When the viscosity is 2000 Pa · s or less, it can be regarded as “liquid” in the present invention, and the member can be easily applied at a high temperature.

[Low temperature properties]
The properties of the active energy ray-curable compositions obtained in the following Examples and Comparative Examples at low temperature were evaluated based on the presence or absence of spinnability of the compositions.
Specifically, the active energy ray-curable composition was formed into a sheet having a thickness of 1 mm, and the obtained sheet-like composition was touched with a finger at room temperature of 25 ° C., and evaluated according to the following criteria.
○: No liquid material adheres to fingers (no spinning property)
×: Liquid adheres to finger (has spinnability)
In the case of evaluation of “O” having no spinnability, it can be regarded as “gel” in the present invention.

[Evaluation of oil resistance]
3 mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, Irgacure (registered trademark) 184) as a photopolymerization initiator was added to the active energy ray-curable compositions obtained in the following Examples and Comparative Examples. % Added and mixed. Next, a 1 mm-thick polytetrafluoroethylene tape was stuck on a release surface of a release PET film (K1504, manufactured by Toyobo Co., Ltd.) so that a space of 4 cm wide and 4 cm long was formed. In this space, the prepared active energy ray-curable composition is applied, and then another release PET film (K1504, manufactured by Toyobo Co., Ltd.) is further placed thereon. Pressed. Next, using a UV irradiation device (12A12-A10-HD3A, metal halide lamp, manufactured by GS Yuasa Co., Ltd.), the release PET film is irradiated with ultraviolet rays at 2000 mJ / cm ² to cure the active energy ray-curable composition. I got something. The obtained cured product was cut into strips having a thickness of 1 mm x a width of 20 mm x a length of 50 mm, immersed in an auto fluid (Toyota Auto Fluid WS) at 150 ° C for 70 hours, and then changed in mass and volume. Rate was evaluated.
Mass change rate [%] = {(mass change before and after immersion) / (mass 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)]
(Step (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and purged with nitrogen, while stirring the solution in the flask, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine was further used as a Lewis base. 2.1 g and 42 g of a toluene solution containing 26% by mass of isobutyl bis (2,6-di-t-butyl-4-methylphenoxy) aluminum as an organoaluminum compound were sequentially added, followed by cooling to -30 ° C. To this, 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound was added, and then 118 g of a mixture of 5.1 g of BMA and 113 g of MMA was added as a monomer at a time to start anionic polymerization. Subsequently, the reaction solution was stirred at −30 ° C. for 12 hours, and the reaction solution was sampled.
The consumption rate of BMA and MMA in the step (1) was 100%.

(Step (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 was completed.
The consumption rate of 2-MEA in the step (2) was 100%.

(Step (3))
Subsequently, 99 g of a mixture of 4.3 g of BMA and 95 g of MMA was added as a monomer while stirring the reaction solution 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 BMA and MMA in step (3) was 100%.

(Step (4))
Subsequently, while stirring the reaction solution at 25 ° C., anionic polymerization was stopped by adding 40 g of methanol, and methacrylic polymer block (a) -acrylic polymer block (b) -methacrylic polymer block (a). (Meth) acrylic block copolymer (hereinafter referred to as "(meth) acrylic block copolymer (I-1)") which is a triblock copolymer bonded in the order of (a-ba) Was obtained. Mw of the (meth) acrylic block copolymer (I-1) sampled from such a solution was 53,800 and Mw / Mn was 1.08. Further, the content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I-1) was 47% by mass.

(Step (5))
Next, the resulting solution was poured into 5,000 g of methanol to precipitate an oily precipitate. After collecting and drying the oily precipitate, 420 g of a (meth) acrylic block copolymer (I-1) was obtained.

[Synthesis Example 2: Synthesis of (meth) acrylic block copolymer (I-2)]
(Step (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and purged with nitrogen, while stirring the solution in the flask, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine was further used as a Lewis base. 2.1 g and 42 g of a toluene solution containing 26% by mass of isobutyl bis (2,6-di-t-butyl-4-methylphenoxy) aluminum as an organoaluminum compound were sequentially added, followed by cooling to -30 ° C. To this, 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound was added, and then 154 g of a mixture of 5.1 g of BMA and 149 g of MMA was added as a monomer at a time to start anionic polymerization. Subsequently, the reaction solution was stirred at −30 ° C. for 12 hours, and the reaction solution was sampled.
The consumption rate of BMA and MMA in the step (1) was 100%.

(Step (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 was completed.
The consumption rate of 2-MEA in the step (2) was 100%.

(Step (3))
Subsequently, 129 g of a mixture of 4.3 g of BMA and 125 g of MMA was added as a monomer while stirring the reaction solution 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 BMA and MMA in step (3) was 100%.

(Step (4))
Subsequently, while stirring the reaction solution at 25 ° C., anionic polymerization was stopped by adding 40 g of methanol, and methacrylic polymer block (a) -acrylic polymer block (b) -methacrylic polymer block (a). (Meth) acrylic block copolymer (hereinafter, referred to as "(meth) acrylic block copolymer (I-2)") which is a triblock copolymer bonded in the order of (a-ba) Was obtained. Mw of the (meth) acrylic block copolymer (I-2) sampled from such a solution was 53,700, and Mw / Mn was 1.07. The content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I-2) was 60% by mass.

(Step (5))
Next, the resulting solution was poured into 5,000 g of methanol to precipitate an oily precipitate. After collecting and drying the oily precipitate, 420 g of a (meth) acrylic block copolymer (I-2) was obtained.

[Synthesis Example 3: Synthesis of (meth) acrylic block copolymer (I-3)]
(Step (1))
After adding 1.30 kg of toluene to a 3 L flask whose inside was dried and purged with nitrogen, while stirring the solution in the flask, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine was further used as a Lewis base. 2.1 g and 42 g of a toluene solution containing 26% by mass of isobutyl bis (2,6-di-t-butyl-4-methylphenoxy) aluminum as an organoaluminum compound were sequentially added, followed by cooling to -30 ° C. To this, 5.4 g of a cyclohexane solution containing 10% by mass of sec-butyllithium as an organic lithium compound was added, and then 118 g of a mixture of 5.1 g of BMA and 113 g of MMA was added as a monomer at a time to start anionic polymerization. Subsequently, the reaction solution was stirred at −30 ° C. for 12 hours, and the reaction solution was sampled.
The consumption rate of BMA and MMA in the step (1) was 100%.

(Step (2))
Subsequently, 292 g of BA 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 was completed.
The consumption rate of BA in the step (2) was 100%.

(Step (3))
Subsequently, 99 g of a mixture of 4.3 g of BMA and 95 g of MMA was added as a monomer while stirring the reaction solution 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 BMA and MMA in step (3) was 100%.

(Step (4))
Subsequently, while stirring the reaction solution at 25 ° C., anionic polymerization was stopped by adding 40 g of methanol, and methacrylic polymer block (a) -acrylic polymer block (b) -methacrylic polymer block (a). (Meth) acrylic block copolymer (hereinafter referred to as "(meth) acrylic block copolymer (I-3)") which is a triblock copolymer bonded in the order of (a-ba) Was obtained. Mw of the (meth) acrylic block copolymer (I-3) sampled from this solution was 53,000, and Mw / Mn was 1.07. Further, the content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I-3) was 45% by mass.

(Step (5))
Next, the resulting solution was poured into 5,000 g of methanol to precipitate an oily precipitate. After collecting the oily precipitate, it was dried to obtain 420 g of a (meth) acrylic block copolymer.

[Example 1]
6 g of the (meth) acrylic block copolymer (I-1) and polyethylene glycol diacrylate (light acrylate 14EG-A, manufactured by Kyoeisha Chemical Co., Ltd., a repeating unit of oxyalkylene unit) as the (meth) acrylic monomer Number: 14) 4 g of (hereinafter, referred to as “(meth) acrylic monomer (II-1)”) was mixed and heated and stirred at 100 ° C. to obtain 10 g of an active energy ray-curable composition. .
The physical properties of the obtained active energy ray-curable composition were measured and evaluated by the methods described above. Table 2 shows the results.

[Examples 2 to 9, Comparative Examples 1 to 4]
The type and amount of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) were changed as shown in Table 2, and the use of 4-hydroxybutyl acrylate and isodecyl acrylate An active energy ray-curable composition was obtained in the same manner as in Example 1 except that the amounts were as shown in Table 2.
However, the (meth) acrylic monomer (II) in Table 2 represents the following.
(Meth) acrylic monomer (II-2): polyethylene glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate 9EG-A, number of repeating oxyalkylene units: 9)
(Meth) acrylic monomer (II-3): polyethylene glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate 4EG-A, number of repeating oxyalkylene units: 4)
(Meth) acrylic monomer (II-4): methoxy polyethylene glycol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Bismer MPE550A, number of repeating oxyalkylene units: 13)
(Meth) acrylic monomer (II-5): methoxy polyethylene glycol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., bismer MPE400A, number of repeating oxyalkylene units: 9)

  The physical properties of the obtained active energy ray-curable composition were measured and evaluated by the methods described above. Table 2 shows the results.

From the results shown in Table 2, in Examples 1 to 9 satisfying the requirements of the present invention, there is no spinnability at 25 ° C. and the gel is formed, but at 80 ° C., the viscosity becomes 2000 Pa · s or less and the liquid is liquid. It can be seen that the state changes between liquid and gel between and low temperatures. Furthermore, in the oil resistance evaluation, since the mass and volume change rates are small, it is understood that the oil resistance is excellent.
On the other hand, the methacrylic polymer block (a) is based on the total mass of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) contained in the active energy ray-curable composition. In Comparative Example 1 in which the content was less than 15% by mass, a gel was not formed at 25 ° C., and in Comparative Example 2 in which the content was more than 50% by mass, the (meth) acrylic block copolymer (I) Solid content remained. Furthermore, in Comparative Example 3 using 4-hydroxybutyl acrylate instead of the (meth) acrylic monomer (II), a gel was not formed at 25 ° C. In Comparative Example 4 using isodecyl acrylate, Although it shows a gel state at 25 ° C., it can be seen that the oil resistance is inferior since the rate of change in mass and volume has increased in the evaluation of oil resistance.

Claims (4)

A methacrylic polymer block (a) having an active energy ray-curable group containing a partial structure (1) represented by the following general formula (1), and an acrylic polymer block not having an active energy ray-curable group ( b) and a (meth) acrylic block copolymer (I) having a weight average molecular weight of 20,000 or more, and a (meth) acrylic monomer (II) having a polyoxyalkylene structure An active energy ray-curable composition,
The methacrylic polymer block (a) is based on the total mass of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) contained in the active energy ray-curable composition. ) Is 15 to 50% 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 active energy ray-curable composition according to claim 1, wherein the content of the methacrylic polymer block (a) in the (meth) acrylic block copolymer (I) is 17 to 80% by mass.   The mass ratio (I) / (II) of the (meth) acrylic block copolymer (I) and the (meth) acrylic monomer (II) is 40/60 to 80/20. The active energy ray-curable composition according to 1 or 2. The active energy ray-curable composition according to any one of claims 1 to 3, wherein the number of repeating oxyalkylene units in the (meth) acrylic monomer (II) is 3 to 100.