JP6606498B2 - Adhesive, adhesive, and method for producing adhesive - Google Patents

Description

  The present invention relates to an adhesive, an adhesive body, and a method for manufacturing the adhesive body.

  Films containing polyvinyl alcohol (hereinafter sometimes referred to as “PVA films”) are excellent in moisture permeability, heat retention, and the like, and are used in various fields such as the food packaging field, the agricultural field, and the medical field. In particular, the stretched PVA film is used as an optical film such as a polarizing film or a retardation film.

  As for the said polarizing film, the protective film is normally bonded together through the aqueous solvent containing adhesive agent etc. on the single side | surface or both surfaces. As this protective film, for example, a transparent film such as a triacetyl cellulose (TAC) film having high moisture permeability has been used.

  In recent years, in order to improve the strength and durability of the protective film, a film other than a TAC film such as a (meth) acrylic polymer film, a polyester film, or an alicyclic structure-containing polymer film is used instead of the conventional TAC film. (See, for example, Japanese Patent Application Laid-Open No. 2008-241945). However, since these films have relatively low moisture permeability, when the aqueous solvent-containing adhesive is used, the moisture in the adhesive is difficult to evaporate, and it takes time to cure the adhesive. There is a disadvantage that the adhesive strength is low.

  In response to the above inconveniences, active energy ray-curable compositions such as ultraviolet rays containing urethane (meth) acrylate obtained from a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate compound have been developed (for example, International Publication No. 2010/123082). However, there is room for improvement in adhesive strength.

JP 2008-241945 A International Publication No. 2010/123082

  The present invention has been made on the basis of the above-mentioned circumstances, and has an adhesive body having high adhesive strength in adhesion between a film containing polyvinyl alcohol and a substrate, excellent in curing speed, and reduced in warpage. It is an object of the present invention to provide an adhesive that can be obtained, an adhesive obtained using the adhesive, and a method for producing the adhesive.

  The invention made to solve the above problems is an adhesive for bonding a film containing polyvinyl alcohol and a substrate, and a (meth) acrylic polymer (X) having an active energy ray-curable group And a compound (Y) having an active energy ray-curable group other than the (meth) acrylic polymer (X) (hereinafter, the adhesive may be referred to as “adhesive (1)”). .

  Moreover, another invention made | formed in order to solve the said subject is an adhesive agent for adhere | attaching the film and base material containing polyvinyl alcohol, Comprising: Polymer (X ') which has an active energy ray hardening group And a compound (Y ′) having an active energy ray-curable group other than the polymer (X ′), and obtained from a storage elastic modulus of a rubber-like flat region obtained by dynamic viscoelasticity measurement after curing. The crosslinking density is 0.4 mol / L or more and 2 mol / L or less (hereinafter, the adhesive may be referred to as “adhesive (2)”).

  Moreover, another invention made | formed in order to solve the said subject is an adhesive body provided with the film containing polyvinyl alcohol, the base material, the adhesive layer arrange | positioned between the film containing polyvinyl alcohol, and a base material. And the said adhesive bond layer is formed from the said adhesive agent.

  Furthermore, another invention made in order to solve the above-mentioned problems is that after the step of obtaining a laminate including a film containing polyvinyl alcohol, the adhesive, and the substrate arranged in this order, and the step of obtaining the laminate, It is a manufacturing method of an adhesion object provided with the process of irradiating the above-mentioned adhesive with active energy rays.

  Since the adhesive (1) contains the (meth) acrylic polymer (X) and the compound (Y) having an active energy ray-curable group as described above, the (meth) acrylic polymer (X ) To the substrate, the film containing the polyvinyl alcohol of the compound (Y) and the adhesion to the substrate, the interaction between the (meth) acrylic polymer (X) and the compound (Y), etc. It is thought that the adhesive body excellent in the adhesive strength and hardening rate of the film containing alcohol and a base material, and the curvature was reduced can be obtained.

  Moreover, the said adhesive agent (2) is excellent in the balance of the adhesiveness to the film and base material containing polyvinyl alcohol, and the intensity | strength of the hardened | cured material itself of the said adhesive agent, when the crosslinking density after hardening exists in a specific range. Therefore, it is considered that an adhesive body with improved adhesive strength and reduced warpage can be obtained, and the curing speed is also excellent.

  Moreover, since the adhesive layer is formed from the adhesive as described above, the adhesive has excellent adhesive strength between the film containing polyvinyl alcohol and the substrate, and warpage is reduced. Furthermore, according to the manufacturing method of the said adhesive body, the said adhesive body can be manufactured easily and reliably.

  Here, the “active energy ray-curable group” means a functional group that exhibits polymerizability upon irradiation with active energy rays, and includes a functional group that exhibits polymerizability through the action of an active energy ray polymerization initiator. “(Meth)” such as “(meth) acrylic polymer” means to include both notation with “meta” and notation with “meta”, and notation with “meta” and “ Indicates that either of the notation without "meta" may be used. For example, “(meth) acrylic polymer” includes “methacrylic polymer” and “acrylic polymer”, and indicates that either “methacrylic polymer” or “acrylic polymer” may be used. . “Peel adhesion strength” is a value measured in accordance with JIS K6854-2 (1999).

  As described above, the adhesive of the present invention has a high adhesive strength in the adhesion between a film containing polyvinyl alcohol and a base material, and can provide an adhesive body having excellent curing speed and reduced warpage. Moreover, the adhesive body of this invention is excellent in the adhesive strength of the film and base material containing polyvinyl alcohol, and curvature is reduced. Furthermore, the manufacturing method of the adhesive body of this invention can manufacture the said adhesive body excellent in the adhesive strength of the film containing a polyvinyl alcohol, and a base material, and the curvature was reduced easily and reliably.

FIG. 1 is a cross-sectional view schematically showing an example of the adhesive body of the present invention.

  Hereinafter, embodiments of the adhesive, the adhesive body, and the manufacturing method of the adhesive body of the present invention will be described in detail.

<Adhesive (1)>
The adhesive (1) is an adhesive for bonding a film containing polyvinyl alcohol and a substrate, and comprises a (meth) acrylic polymer (X) having an active energy ray-curable group, ) A compound (Y) having an active energy ray-curable group other than the acrylic polymer (X).

[(Meth) acrylic polymer (X)]
The (meth) acrylic polymer (X) has at least one active energy ray-curable group in the molecule. The active energy ray-curable group of the (meth) acrylic polymer (X) is bonded to the compound (Y) and cured, or the (meth) acrylic polymer (X) is cured alone. It is considered that the adhesive strength and the curing rate between the film containing polyvinyl alcohol and the substrate are excellent and the warpage of the bonded body can be reduced.

  Examples of the active energy rays include electromagnetic waves such as ultraviolet rays, infrared rays, X rays, and γ rays, as well as electron rays, proton rays, and neutron rays. Among these, ultraviolet rays or electron beams are preferred from the viewpoints of curing speed, availability of irradiation equipment, price, etc., and ultraviolet rays are more preferred.

  The active energy ray-curable group is not particularly limited as long as it is a functional group that exhibits polymerizability upon irradiation with active energy rays, but has, for example, a group having an ethylenic double bond, a group having an oxirane ring, and an oxetane ring. Group, a group having a thiol group, a group having a maleimide group, a group having a hydrolyzable silyl group, and the like. As a minimum of carbon number of the said active energy ray hardening group, 1 is preferable and 2 is more preferable. On the other hand, the upper limit of the carbon number is preferably 30, and more preferably 15. Examples of the group having an ethylenic double bond include a group having a group represented by the following formula (1) (a group having a (meth) acryloyloxy group); a group having an allyl group; a group having a vinyl group (Groups having a vinyl ether group, etc.); groups having a 1,3-dienyl group; groups having a styryl group.

In the above formula (1), ^{R 1} represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

Examples of R ¹ include a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, 2-methylbutyl group, and 3-methylbutyl group. 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl Group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, n-hexadecyl group, n-eicosyl group and other alkyl groups; cyclopropyl group, cyclobutyl group, cyclopentyl group Cycloalkyl groups such as cyclohexyl group and cyclooctyl group; aryl groups such as phenyl group and naphthyl group. When R ¹ is a hydrocarbon group, the upper limit of the number of carbon atoms is preferably 10, and more preferably 4.

Further, a hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ may have a substituent. The substituent is not particularly limited as long as it does not inhibit the active energy ray curable property of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group; a chlorine atom, A halogen atom such as a bromine atom is exemplified.

R ¹ is preferably a hydrogen atom or a methyl group from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

  Among the active energy ray-curable groups, at least one selected from the group consisting of a group having an ethylenic double bond, a group having an oxirane ring, and a group having an oxetane ring is excellent in handleability and reactivity. Preferably, at least one selected from the group consisting of a group having a group represented by the above formula (1), a group having an oxirane ring, and a group having an oxetane ring is more preferred, and a group represented by the above formula (1) More preferred are groups having

  The group having a group represented by the above formula (1) is not particularly limited, but a group represented by the following formula (2) is preferable because the effects of the present invention are more remarkably exhibited.

In the above formula (2), R ² and R ³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, X ¹ represents an oxygen atom, a sulfur atom or —NR ⁴ —, and R ⁴ Represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and n represents an integer of 1 to 20.

In addition, the definition and description of R ¹ in the above formula (2) are the same as those in the above formula (1).

Examples of R ² and R ³ include a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, 2-methylbutyl group, 3 -Methylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3 -An alkyl group such as a methylpentyl 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;

Further, the hydrocarbon group having 1 to 6 carbon atoms represented by R ² and R ³ may have a substituent. The substituent is not particularly limited as long as it does not inhibit the active energy ray curable property of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group; a chlorine atom, A halogen atom such as a bromine atom is exemplified.

R ² and R ³ are each preferably a methyl group or an ethyl group from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

Examples of the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁴ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. 2-methylbutyl group, 3-methylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group, Examples thereof include alkyl groups such as 2-methylpentyl group and 3-methylpentyl group; cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group.

Moreover, the C1-C6 hydrocarbon group represented by R < ⁴ > may have a substituent. The substituent is not particularly limited as long as it does not inhibit the active energy ray curable property of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group; a chlorine atom, A halogen atom such as a bromine atom is exemplified.

R ⁴ is preferably a methyl group or an ethyl group from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

X ¹ is preferably an oxygen atom or —NR ⁴ —, more preferably an oxygen atom, from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

  From the standpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed, the lower limit of n is preferably 2, while the upper limit of n is preferably 10, and more preferably 5.

  The (meth) acrylic polymer (X) is a polymer mainly containing a structural unit derived from a (meth) acrylic monomer, and may be a homopolymer or a copolymer. Examples of the (meth) acrylic monomer include those having a partial structure represented by the following formula (4). Here, in the (meth) acrylic polymer (X), part or all of the structural unit derived from the (meth) acrylic monomer having a partial structure represented by the following formula (4) is cured by active energy rays. A structure derived from a (meth) acrylic monomer having a partial structure represented by the following formula (4), which may have an active energy ray-curable group as a result of having a functional group Even when some or all of the units do not have an active energy ray-curable group, by having an active energy ray-curable group at the terminal and / or side chain of the polymer, As a result, a (meth) acrylic polymer (X) having an active energy ray-curable group can be obtained.

In the above formula (4), R ⁷ represents a hydrogen atom or a methyl group, X ³ represents an oxygen atom, a sulfur atom or —NR ⁸ —, and R ⁸ represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. To express.

R ⁷ is preferably a methyl group.

Examples of the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁸ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. 2-methylbutyl group, 3-methylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group, Examples thereof include alkyl groups such as 2-methylpentyl group and 3-methylpentyl group; cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group.

Further, the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁸ may have a substituent. The substituent is not particularly limited as long as it does not hinder the active energy ray curability of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, or a t-butoxy group; a chlorine atom And halogen atoms such as bromine atom.

R ⁸ is preferably a methyl group or an ethyl group from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

X ³ is preferably an oxygen atom or —NR ⁸ —, more preferably an oxygen atom, from the viewpoint of ease of production of the (meth) acrylic polymer (X) and excellent curing speed.

Specific examples of the (meth) acrylic monomer in the case where X ³ is an oxygen atom include compounds having an active energy ray-curable group and a (meth) acryloyloxy group in addition thereto. . In addition, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth) acrylic T-butyl acid, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, trimethoxysilyl (meth) acrylate Propyl, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, phenyl (meth) acrylate, naphthyl (meth) acrylate , 2- (trimethylsilyloxy) ethyl (meth) acrylate, (meth) acrylic An acid 3- (trimethylsilyloxy) propyl may be mentioned.

  The lower limit of the proportion of the number of moles of structural units derived from the (meth) acrylic monomer to the number of moles of all structural units constituting the (meth) acrylic polymer (X) is preferably 30 mol%, 50 mol% is more preferable, 80 mol% is further more preferable, 95 mol% is especially preferable, and the said ratio may be 100 mol%.

  Further, the lower limit of the proportion of the number of moles of the active energy ray-curable group to the number of moles of all structural units constituting the (meth) acrylic polymer (X) is preferably 0.3 mol%, and preferably 1 mol%. Is more preferable, and 2 mol% is further more preferable. On the other hand, the upper limit of the ratio is preferably 90 mol%, more preferably 30 mol%, further preferably 15 mol%, and particularly preferably 10 mol%. When the ratio of the number of moles of active energy ray-curable groups to the number of moles of all structural units constituting the (meth) acrylic polymer (X) is in the above range, the adhesive (2) described later can be easily obtained. In addition, it is easy to obtain an adhesive capable of further improving the adhesive strength and further reducing the warpage.

  When the (meth) acrylic polymer (X) is a copolymer, examples of the (meth) acrylic polymer (X) include a random copolymer and a block copolymer. Examples of the random copolymer include (meth) acrylic polymers (acrylic resin (meth) acrylate etc.) having (meth) acryloyloxy groups at the terminal and / or side chain. As the (meth) acrylic polymer (X), it is possible to obtain an adhesive with particularly reduced warpage, and the effects of the present invention are more remarkably exhibited. Therefore, a block copolymer is preferable and active. Block copolymer having a (meth) acrylic polymer block (A) having an energy ray-curable group and a (meth) acrylic polymer block (B) having substantially no active energy ray-curable group Coalescence is more preferred. Thus, the adhesive is based on the fact that the (meth) acrylic polymer (X) has the (meth) acrylic polymer block (A) and the (meth) acrylic polymer block (B). It is considered that the followability to the unevenness on the surface of the material is improved, the warp is further reduced by the anchor effect and the adhesive strength is further improved.

((Meth) acrylic polymer block (A))
The (meth) acrylic polymer block (A) is a (meth) acrylic polymer block having an active energy ray-curable group. The lower limit of the proportion of the number of moles of structural units derived from the (meth) acrylic monomer to the number of moles of all structural units constituting the (meth) acrylic polymer block (A) is preferably 30 mol%. , 50 mol% is more preferable, 80 mol% is more preferable, 95 mol% is particularly preferable, and the above ratio may be 100 mol%.

  The (meth) acrylic polymer block (A) is a vinyl compound having an active energy ray-curable group and another ethylenic double bond (hereinafter referred to as “active energy ray-curable monomer”). It preferably has a structural unit formed by addition polymerization of ethylenic double bonds.

  Preferred examples of the active energy ray-curable monomer include compounds represented by the following formula (5). As the compound represented by the formula (5), one type may be used alone, or two or more types may be used in combination.

In the above formula (5), the definitions and explanations for each of R ¹ , R ² , R ³ , X ¹ and n are the same as those in the above formula (1) and the above formula (2). In the above formula (5), a plurality of R ¹ may be the same or different from each other, but may be the same due to the ease of production of the compound represented by the formula (5). preferable.

  As the active energy ray-curable monomer, in addition to the compound represented by the above formula (5), for example, a group having an oxirane ring and a vinyl compound having an ethylenic double bond, a group having an oxetane ring and ethylene It may be a vinyl compound having an ionic double bond. The active energy ray-curable monomer may be used alone or in combination of two or more.

  As a minimum of the content rate of the structural unit derived from the active energy ray hardening monomer with respect to all the structural units which form a (meth) acrylic-type polymer block (A), 5 mol% is preferable and 10 mol% is more. Preferably, 20 mol% is more preferable. On the other hand, the upper limit of the content is preferably 90 mol%, more preferably 70 mol%, but the structural unit derived from the (meth) acrylic monomer contained in the (meth) acrylic polymer block (A). Is formed from an active energy ray-curable monomer, the upper limit of the content may be 100 mol%.

  The (meth) acrylic polymer block (A) is mono (meth) acrylic acid as a structural unit derived from a (meth) acrylic monomer in addition to a structural unit derived from an active energy ray-curable monomer. You may have the structural unit derived from ester.

  Examples of the mono (meth) acrylate ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , T-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, (meth) Trimethoxysilylpropyl acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, phenyl (meth) acrylate, ( Naphthyl (meth) acrylate, 2- (trimethylsilyloxy) (meth) acrylate ) Ethyl, and the like (meth) acrylic acid 3- (trimethylsilyloxy) propyl. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate A (meth) acrylic acid alkyl ester having an alkyl group having 5 or less carbon atoms such as is preferred. Moreover, as mono (meth) acrylic acid ester, monomethacrylic acid ester is preferable. These mono (meth) acrylic acid esters may be used alone or in combination of two or more.

  As an upper limit of the content rate of the structural unit derived from the said mono (meth) acrylic acid ester with respect to all the structural units which form a (meth) acrylic-type polymer block (A), 95 mol% is preferable and 90 mol% is more. Preferably, 80 mol% is more preferable. On the other hand, as a minimum of the above-mentioned content rate, 0 mol% is preferred, 20 mol% is more preferred, and 30 mol% is still more preferred.

  The (meth) acrylic polymer block (A) is a structural unit derived from a (meth) acrylic monomer, or other structural unit, and the active energy ray-curable monomer and mono ( You may have the structural unit derived from other monomers other than (meth) acrylic acid ester.

  Examples of the other monomers include α-alkoxy acrylates such as methyl α-methoxyacrylate and methyl α-ethoxyacrylate; crotonates such as methyl crotonate and ethyl crotonate; 3-methoxyacrylic acid. 3-alkoxyacrylic esters such as esters; N-isopropylacrylamide, Nt-butylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide and other acrylamides; N-isopropylmethacrylamide, Nt-butyl Methacrylamide such as methacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide; methyl 2-phenylacrylate, ethyl 2-phenylacrylate, n-butyl 2-bromoacrylate, 2-bromomethyl Acrylic acid Chill, 2-bromomethyl acrylate, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, and ethyl isopropenyl ketone. These other monomers may be used individually by 1 type, and may use 2 or more types together.

  As an upper limit of the content rate of the structural unit derived from the said other monomer with respect to all the structural units which form a (meth) acrylic-type polymer block (A), 10 mol% is preferable and 5 mol% is more preferable.

  Although there is no restriction | limiting in particular in the number average molecular weight (Mn) of a (meth) acrylic-type polymer block (A), From points, such as the handleability of the (meth) acrylic-type polymer (X) obtained, fluidity | liquidity, a mechanical characteristic. The lower limit of Mn is preferably 500, more preferably 1,000. On the other hand, the upper limit of Mn is preferably 1,000,000, and more preferably 300,000.

((Meth) acrylic polymer block (B))
The (meth) acrylic polymer block (B) is a (meth) acrylic polymer block having substantially no active energy ray-curable group. Here, as an example in the case of having substantially no active energy ray-curable group, derived from the active energy ray-curable monomer for all structural units forming the (meth) acrylic polymer block (B) For example, the content of the structural unit is less than 5 mol%, less than 3 mol%, less than 1 mol%, less than 0.5 mol%, or even 0 mol%. The lower limit of the proportion of the number of moles of structural units derived from the (meth) acrylic monomer to the number of moles of all structural units constituting the (meth) acrylic polymer block (B) is preferably 30 mol%. , 50 mol% is more preferable, 80 mol% is more preferable, 95 mol% is particularly preferable, and the above ratio may be 100 mol%.

  The (meth) acrylic polymer block (B) can have a structural unit derived from a (meth) acrylic acid ester as a structural unit derived from a (meth) acrylic monomer. Examples of such (meth) acrylic acid esters include monoacrylic acid esters and monomethacrylic acid esters.

  Examples of the monoacrylate 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 Examples include naphthyl, 2- (trimethylsilyloxy) ethyl acrylate, 3- (trimethylsilyloxy) propyl acrylate, and the like.

  Examples of the monomethacrylate include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid. Isobornyl acid, lauryl methacrylate, dodecyl methacrylate, trimethoxysilylpropyl methacrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, 2-methoxyethyl methacrylate, phenyl methacrylate, methacrylic acid Examples include naphthyl, 2- (trimethylsilyloxy) ethyl methacrylate, 3- (trimethylsilyloxy) propyl methacrylate, and the like.

  As the (meth) acrylic acid ester, an acrylic acid alkyl ester having an alkyl group having 4 or more carbon atoms and a methacrylic acid alkyl ester having an alkyl group having 6 or more carbon atoms are preferable, and n-butyl acrylate, t-acrylic acid t- Butyl, 2-ethylhexyl acrylate, lauryl acrylate, dodecyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and dodecyl methacrylate are more preferable. In addition, these (meth) acrylic acid ester may be used individually by 1 type, and may use 2 or more types together.

  As a minimum of the content rate of the structural unit derived from the said (meth) acrylic ester with respect to all the structural units which form a (meth) acrylic-type polymer block (B), 90 mol% is preferable and 95 mol% is more preferable. .

  The (meth) acrylic polymer block (B) is a structural unit derived from a (meth) acrylic monomer, or other structural unit other than the above (meth) acrylic acid ester. It may have a structural unit derived from the body. Examples of other monomers include α-alkoxy acrylates such as α-methyl methoxyacrylate and α-methyl ethoxy acrylate; crotonic acid esters such as methyl crotonate and ethyl crotonate; 3-methoxy acrylate, etc. 3-alkoxyacrylic acid ester; acrylamide such as N-isopropylacrylamide, Nt-butylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide; N-isopropylmethacrylamide, Nt-butylmethacrylamide And methacrylamide such as N, N-dimethylmethacrylamide and N, N-diethylmethacrylamide; methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, and ethyl isopropenyl ketone. These other monomers may be used individually by 1 type, and may use 2 or more types together.

  As an upper limit of the content rate of the structural unit derived from the said other monomer with respect to all the structural units which form a (meth) acrylic-type polymer block (B), 10 mol% is preferable and 5 mol% is more preferable.

  Although there is no restriction | limiting in particular in the number average molecular weight (Mn) of a (meth) acrylic-type polymer block (B), From points, such as the handleability of the obtained (meth) acrylic-type polymer (X), fluidity | liquidity, and mechanical characteristics. The lower limit of Mn is preferably 3,000, and more preferably 5,000. On the other hand, the upper limit of Mn is preferably 5,000,000, and more preferably 1,000,000.

  The (meth) acrylic polymer (X) is a block copolymer in which at least one (meth) acrylic polymer block (A) and at least one (meth) acrylic polymer block (B) are bonded to each other. It is preferably a coalescence. When the (meth) acrylic polymer (X) is a block copolymer having a (meth) acrylic polymer block (A) and a (meth) acrylic polymer block (B), The number and the bonding order are not particularly limited, but from the viewpoint of easy production of the (meth) acrylic polymer (X), one (meth) acrylic polymer block (A) and one (meth) A diblock copolymer to which the acrylic polymer block (B) is bonded and one (meth) acrylic polymer block (A) at each end of one (meth) acrylic polymer block (B). A bonded triblock copolymer is preferred. In this way, the block at both ends of the (meth) acrylic polymer (X) is the (meth) acrylic polymer block (A) having an active energy ray-curable group. It is considered that the combined blocks (A) interact with each other during polymerization and curing of the adhesive to form a network structure, so that the toughness after curing of the adhesive is improved, and as a result, the adhesive strength is further improved. Further, the presence of the (meth) acrylic polymer block (B) between the (meth) acrylic polymer blocks (A) is considered to further reduce the warpage of the obtained adhesive.

  When (meth) acrylic polymer (X) is a block copolymer having (meth) acrylic polymer block (A) and (meth) acrylic polymer block (B), (meth) acrylic The constituent ratio of the polymer block (A) and the (meth) acrylic polymer block (B) is preferably 5:95 or more and 90:10 or less by mass ratio. When the ratio of the (meth) acrylic polymer block (A) to the total of the (meth) acrylic polymer block (A) and the (meth) acrylic polymer block (B) is 5% by mass or more, the active energy The curing speed by the line and the adhesive strength after curing are good. On the other hand, when the proportion of the (meth) acrylic polymer block (B) is 10% by mass or more, the viscoelasticity of the adhesive after curing becomes good.

  The number average molecular weight (Mn) of the entire (meth) acrylic polymer (X) is not particularly limited, but from the viewpoints of handleability, fluidity, mechanical properties, etc. of the (meth) acrylic polymer (X) As a lower limit of Mn, 4,000 is preferable, 5,000 is more preferable, and 7,000 is more preferable. On the other hand, the upper limit of Mn is preferably 7,000,000, more preferably 3,000,000, and further preferably 2,000,000.

  The molecular weight distribution (Mw / Mn) of the entire (meth) acrylic polymer (X) is not particularly limited, but the upper limit of the Mw / Mn is preferably 2.0, more preferably 1.5. 2 is more preferable. Thus, the adhesive strength and the cure rate of the adhesive can be further increased by setting the Mw / Mn to the upper limit or less.

  As a minimum of the content rate of (meth) acrylic-type polymer (X) in the said adhesive agent (1), 1 mass% is preferable, 3 mass% is more preferable, 5 mass% is further more preferable, and 10 mass% is especially. Preferably, the said content rate is good also as 15 mass% or more. On the other hand, the upper limit of the content is preferably 90% by mass, more preferably 70% by mass, and particularly preferably 50% by mass. When the content is equal to or higher than the lower limit, an adhesive body in which mechanical properties such as adhesive strength of the adhesive are further improved and warpage is further reduced can be obtained. On the other hand, when the content is less than or equal to the above upper limit, the viscosity of the adhesive can be appropriately maintained, and the handleability is improved.

(Method for producing (meth) acrylic polymer (X))
There is no restriction | limiting in particular in the manufacturing method of (meth) acrylic-type polymer (X), For example, it obtains by superposing | polymerizing the said active energy ray hardening monomer with another (meth) acrylic-type monomer as needed. be able to. In the case where the (meth) acrylic polymer (X) is a block copolymer having a (meth) acrylic polymer block (A) and a (meth) acrylic polymer block (B), active energy ray curability is used. A monomer containing a monomer and a monomer containing a (meth) acrylic monomer is anionic polymerized in the presence of an organolithium compound, a tertiary organoaluminum compound and a Lewis base. A monomer that does not substantially contain an active energy ray-curable monomer after the polymerization step and the first polymerization step and that contains a (meth) acrylic monomer is added, and anionic polymerization is performed. A production method including the second polymerization step is preferable. According to this production method, the target (meth) acrylic polymer (X) can be produced efficiently. In this case, after the second polymerization step, a monomer containing an active energy ray-curable monomer and a monomer containing a (meth) acrylic monomer is added to perform anionic polymerization. A three polymerization step may be further provided.

(First polymerization step)
In the first polymerization step, a monomer containing an active energy ray-curable monomer and a monomer containing a (meth) acrylic monomer is converted into an organolithium compound and a tertiary organoaluminum compound. And anionic polymerization in the presence of Lewis base. The monomer used in the first polymerization step may contain an active energy ray-curable monomer as a (meth) acrylic monomer, and in addition to the active energy ray-curable monomer ( It may contain a (meth) acrylic monomer. The content of the active energy ray-curable monomer in the monomer used in the first polymerization step is preferably 5 mol% or more and 100 mol% or less.

In the first polymerization step, when using the compound represented by the above formula as the active energy ray-curable monomer (5), at least one of R ² and R ^3, preferably both R ² and R ³ are both It is preferably a hydrocarbon group having 1 to 6 carbon atoms. Thus, when R ² and / or R ³ is a hydrocarbon group having 1 to 6 carbon atoms, —OCO—CR ¹ ═CH ₂ that is directly bonded to the carbon atom to which R ² and R ³ are bonded. The ethylenic double bond on the non-group side is selectively polymerized, while the polymerization of the —OCO—CR ¹ ═CH ₂ group directly bonded to the carbon atom to which R ² and R ³ are bonded is suppressed ( Since it remains in the side chain of the (meth) acrylic polymer (X), it is preferable. The active energy ray-curable monomer used in the first polymerization step may be only one type or two or more types.

  The monomer used in the first polymerization step may contain a mono (meth) acrylic acid ester as a (meth) acrylic monomer in addition to the active energy ray-curable monomer. As this mono (meth) acrylic acid ester, for example, the same mono (meth) acrylic acid ester as exemplified in the above (meth) acrylic polymer block (A) can be used. Mono (meth) acrylic acid ester may use only 1 type, and may use 2 or more types.

  As an upper limit of the ratio of the active energy ray-curable monomer to the total of the active energy ray-curable monomer and the mono (meth) acrylate ester in the monomer used in the first polymerization step, 100 mol% is preferable, 80 mol% is more preferable, and 70 mol% is further more preferable. On the other hand, as a minimum of the above-mentioned ratio, 5 mol% is preferred, 10 mol% is more preferred, and 20 mol% is still more preferred. By making the said ratio into the said range, the speed | rate of the anion polymerization in a 1st superposition | polymerization process, the hardening rate of the said adhesive agent, and the adhesive strength after hardening improve more.

  In the first polymerization step, as the (meth) acrylic monomer or other monomer, other monomers other than the active energy ray-curable monomer and mono (meth) acrylic acid ester are used. It may be polymerized. As the said other monomer, the thing similar to the other monomer illustrated, for example in the said (meth) acrylic-type polymer block (A) can be used. Only 1 type may be used for another monomer and 2 or more types may be used for it.

  In the first polymerization step, the upper limit of the amount of the other monomer used relative to the total of the active energy ray-curable monomer, mono (meth) acrylate and other monomers is preferably 10 mol%, 5 mol% is more preferable. When the usage amount is equal to or less than the upper limit, the curing rate of the adhesive and the adhesive strength after curing are further improved.

  Monomers used in the first polymerization step (active energy ray-curable monomers and optional mono (meth) acrylates and other monomers) are not suitable from the viewpoint of smoothly proceeding anionic polymerization. It is preferable to perform a drying treatment in advance in an active gas atmosphere. Examples of the treatment agent used for the drying treatment include dehydrating agents or drying agents such as calcium hydride, molecular sieves, and activated alumina.

  The organolithium compound acts as an anionic polymerization initiator. Examples of the organolithium compound include C3-C30 organolithium compounds having a structure having a carbon atom as an anion center. Examples of such organic lithium compounds include t-butyllithium, 2,2-dimethylpropyllithium, 1,1-diphenylhexyllithium, 1,1-diphenyl-3-methylpentyllithium, ethyl α-lithioisobutyrate. Butyl α-lithioisobutyrate, methyl α-lithioisobutyrate, isopropyl lithium, sec-butyl lithium, 1-methylbutyl lithium, 2-ethylpropyl lithium, 1-methylpentyl lithium, cyclohexyl lithium, diphenylmethyl lithium, α-methylbenzyl lithium, methyl lithium, n-propyl lithium, n-butyl lithium, n-pentyl lithium, n-hexyl lithium and the like can be mentioned. These organolithium compounds may be used individually by 1 type, and may use 2 or more types together.

  Examples of the organic lithium compound include isopropyl lithium, sec-butyl lithium, 1-methylbutyl lithium, 1-methylpentyl lithium, cyclohexyl lithium, diphenylmethyl lithium, α-methylbenzyl lithium from the viewpoints of availability and anion polymerization initiation ability. An organolithium compound having 4 to 15 carbon atoms having a structure having a secondary carbon atom as the anion center, such as sec-butyllithium, is more preferred.

  As the amount of the organic lithium compound used relative to the total amount of monomers (active energy ray-curable monomer and mono (meth) acrylate ester and other monomers which are optional components) used in the first polymerization step, 0.0001 mol times or more and 0.3 mol times or less are preferable. By making the usage-amount of an organolithium compound into the said range, the target (meth) acrylic-type polymer (X) can be manufactured smoothly.

  As said tertiary organoaluminum compound, the compound containing the structure represented by following formula (6) is preferable, and the compound represented by following formula (6-1) or (6-2) is more preferable. By using these compounds as the tertiary organoaluminum compound, the polymerization rate, the polymerization initiation efficiency, the stability of the polymerization terminal anion, and the like can be improved. These tertiary organoaluminum compounds may be used alone or in combination of two or more.

  In said formula (6), Ar represents an aromatic ring.

In the above formula (6-1), R ⁹ represents a monovalent saturated hydrocarbon group, a monovalent aromatic hydrocarbon group, an alkoxy group, an aryloxy group or an N, N-2 substituted amino group, and R ¹⁰ and R ¹¹ each independently represents an aryloxy group or an arylenedioxy group bonded to each other.

In the above formula (6-2), R ¹² represents an aryloxy group, and R ¹³ and R ¹⁴ each independently represent a monovalent saturated hydrocarbon group, a monovalent aromatic hydrocarbon group, an alkoxy group, or N, Represents an N-2 substituted amino group.

Examples of the aryloxy group represented by R ⁹ , R ¹⁰ , R ¹¹ and R ¹² include a phenoxy group, a 2-methylphenoxy group, a 4-methylphenoxy group, a 2,6-dimethylphenoxy group, and a 2,4-dioxy group. -T-butylphenoxy group, 2,6-di-t-butylphenoxy group, 2,6-di-t-butyl-4-methylphenoxy 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, 7-methoxy-2-naphthoxy group and the like.

Examples of the aryleneoxy group represented by R ¹⁰ and R ¹¹ bonded to 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-naphthol and the like in two phenolic hydroxyl groups And a group in which a hydrogen atom is removed.

Examples of the monovalent saturated hydrocarbon group represented by R ⁹ , R ¹³ and R ¹⁴ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, t Examples include -butyl group, 2-methylbutyl group, 3-methylbutyl group, n-octyl group, alkyl group such as 2-ethylhexyl group; and cycloalkyl group such as cyclohexyl group.

Examples of the monovalent aromatic hydrocarbon group represented by R ⁹ , R ¹³ and R ¹⁴ include aryl groups such as a phenyl group; aralkyl groups such as a benzyl group.

Examples of the alkoxy group represented by R ⁹ , R ¹³ and R ¹⁴ include a methoxy group, an ethoxy group, an isopropoxy group, and a t-butoxy group.

Examples of the N, N-2 substituted amino group represented by R ⁹ , R ¹³ and R ¹⁴ include dialkylamino groups such as dimethylamino group, diethylamino group and diisopropylamino group; bis (trimethylsilyl) amino group and the like. .

One or a plurality of hydrogen atoms of R ^{9 to} R ¹⁴ may be substituted with a substituent. Examples of such a substituent include alkoxy groups such as methoxy group, ethoxy group, isopropoxy group and t-butoxy group; halogen atoms such as chlorine and bromine.

  Examples of the tertiary organoaluminum compound represented by the above formula (6-1) include methylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum and 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-methylphenol) Xyl) 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, tris (2,6-diphenylphenoxy) aluminum and the like.

  Among these, as the tertiary organoaluminum compound represented by the above formula (6-1), from the viewpoints of polymerization initiation efficiency, stability of polymerization terminal anion, availability and ease of handling, etc., isobutylbis ( 2,6-di-t-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-di-t-butylphenoxy) aluminum, or isobutyl [2,2′-methylenebis (4-methyl-6-t) -Butylphenoxy)] aluminum is preferred.

  Examples of the tertiary organoaluminum compound represented by the above formula (6-2) include diethyl (2,6-di-t-butyl-4-methylphenoxy) aluminum and diethyl (2,6-di-t-). Butylphenoxy) aluminum, 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-methylphenoxy) aluminum, di-n-octyl (2,6-di-t-butylphenoxy) aluminum and the like.

  The amount of the tertiary organoaluminum compound used can be appropriately selected according to the type of solvent and other various polymerization conditions. From the viewpoint of the polymerization rate, the upper limit of the amount used for 1 mol of the organolithium compound. Is preferably 10 moles, more preferably 5 moles, and still more preferably 4 moles. On the other hand, as a minimum of the usage-amount with respect to 1 mol of organolithium compounds, 1 mol is preferable, 1.1 mol is more preferable, and 1.2 mol is more preferable. It is economically advantageous that the amount used is less than or equal to the upper limit. On the other hand, the starting efficiency of anionic polymerization improves that the said usage-amount is more than the said minimum.

  Examples of the Lewis base include those selected from the group consisting of ethers and tertiary polyamines. This ether means a compound having an ether bond in the molecule. A tertiary polyamine means a compound having two or more tertiary amine structures in the molecule. This Lewis base may use only 1 type and may use 2 or more types.

  The ether is preferably 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 polymerization initiation efficiency and stability of the polymerization terminal anion.

  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 acyclic ether having one or more ether bonds in the molecule include acyclic monoethers, acyclic diethers, and acyclic polyethers.

  Examples of the acyclic monoether include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, and anisole.

  Examples of the acyclic diether include 1,2-dimethoxyethane, 1,2-diethoxyethane, 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-di Ethoxypropane, 1,3-diisopropoxypropane, 1,3-dibutoxypropane, 1,3-diphenoxypropane, 1,4-dimethoxybutane, 1,4-diethoxybutane, 1,4-diisopropoxy Examples include butane, 1,4-dibutoxybutane, 1,4-diphenoxybutane and the like.

  Examples of the acyclic polyether include 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, and 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 Ethyl ether, tetrapropylene glycol diethyl ether, tetrabutylene glycol diethyl ether, and the like.

  Among these, an acyclic ether having one or two ether bonds in the molecule is preferable from the viewpoint of suppression of side reactions, availability, etc., and diethyl ether or 1,2-dimethoxyethane is preferred. Is more preferable.

  Examples of the tertiary polyamine include N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N ″, N ″ -penta. Chain polyamines such as methyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, 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 It is.

  The Lewis base may be a compound having one or more ether bonds and one or more tertiary amine structures in the molecule. Examples of such a compound include tris [2- (2-methoxyethoxy) ethyl] amine.

  The upper limit of the amount of Lewis base used with respect to 1 mol of the organolithium compound is preferably 5 mol, more preferably 3 mol, and even more preferably 2 mol. On the other hand, the lower limit of the amount used is preferably 0.3 mol, more preferably 0.5 mol, and even more preferably 1 mol. It is economically advantageous that the amount used is less than or equal to the upper limit. On the other hand, the starting efficiency of anionic polymerization improves that the said usage-amount is more than the said minimum.

  Moreover, as an upper limit of the usage-amount of the Lewis base with respect to 1 mol of said tertiary organoaluminum compounds, 1.2 mol is preferable and 1 mol is more preferable. On the other hand, the lower limit of the amount used is preferably 0.2 mol, more preferably 0.3 mol.

  In the first polymerization step, other additives may be added to the polymerization reaction system as necessary. Examples of such 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 anionic polymerization in the first polymerization step is preferably performed in the presence of an organic solvent from the viewpoint of easy temperature control and from the viewpoint of smoothing the anionic polymerization by homogenizing the inside of the system. Organic solvents include hydrocarbons such as toluene, xylene, cyclohexane, and methylcyclohexane from the viewpoints of safety, separability from water in washing the reaction mixture after anionic polymerization, and ease of recovery and reuse; chloroform Halogenated hydrocarbons such as methylene chloride and carbon tetrachloride are preferred. These organic solvents may be used individually by 1 type, and may use 2 or more types together. In addition, it is preferable to deaerate the organic solvent in advance in the presence of an inert gas while performing a drying treatment from the viewpoint of smoothly proceeding anionic polymerization.

  In the first polymerization step, the amount of the organic solvent used relative to 100 parts by mass of the monomer used (active energy ray-curable monomer and mono (meth) acrylic ester and other monomers as optional components) is as follows: The monomer, organolithium compound, tertiary organoaluminum compound, Lewis base, other additives, organic solvent, etc. can be adjusted as appropriate, but anionic polymerization proceeds smoothly and is produced (meta) In light of separation and acquisition of the acrylic polymer (X), waste liquid treatment, and the like, the upper limit of the amount used is preferably 10,000 parts by mass, and more preferably 3,000 parts by mass. On the other hand, as a minimum of the above-mentioned amount of use, 150 mass parts is preferred and 200 mass parts is more preferred.

  As a minimum of reaction temperature of anionic polymerization in the 1st polymerization process, -100 ° C is preferred and -30 ° C is more preferred. On the other hand, the upper limit of the reaction temperature of the anionic polymerization is preferably 50 ° C, more preferably 25 ° C. When the reaction temperature of the anionic polymerization is not less than the above lower limit, a decrease in polymerization rate is suppressed and productivity is improved. On the other hand, when the reaction temperature of the anionic polymerization is not more than the above upper limit, polymerization with an active energy ray-curable group in the active energy ray-curable monomer can be more effectively suppressed and obtained (meta ) The active energy ray curability of the acrylic polymer (X) is improved.

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

  In the first polymerization step, monomers (active energy ray-curable monomers and optional mono (meth) acrylic esters and other monomers), organolithium compounds, tertiary organoaluminum compounds and Lewis The method for adding the base to the polymerization reaction system is not particularly limited. For example, the tertiary organoaluminum compound may be added to the polymerization reaction system before the monomer to be used, or may be added simultaneously. When adding to the polymerization reaction system at the same time as the monomer using the tertiary organoaluminum compound, add the tertiary organoaluminum compound and the monomer after mixing separately before adding to the polymerization reaction system. Also good. The Lewis base is preferably added so as to come into contact with the tertiary organoaluminum compound before contact with the organolithium compound.

(Second polymerization step)
In the second polymerization step, a monomer that substantially does not contain the active energy ray-curable monomer after the first polymerization step and that contains a (meth) acrylic monomer is added, Anionic polymerization. Thereby, the monomer which forms (meth) acrylic-type polymer block (B) can further superpose | polymerize in the polymer used as the (meth) acrylic-type polymer block (A) produced | generated at the 1st superposition | polymerization process. . Here, as an example of the case where the active energy ray-curable monomer is not substantially contained, the content of the active energy ray-curable monomer in the monomer used in the second polymerization step is, for example, The case is less than 5 mol%, less than 3 mol%, less than 1 mol%, less than 0.5 mol%, and further 0 mol%.

  Examples of the (meth) acrylic monomer contained in the monomer used in the second polymerization step are the same as the (meth) acrylic acid ester exemplified in the (meth) acrylic polymer block (B). Is mentioned. This (meth) acrylic acid ester may use only 1 type, and may use 2 or more types.

  In the second polymerization step, another monomer other than the (meth) acrylic acid ester may be further added as the (meth) acrylic monomer or as the other monomer. As this other monomer, the thing similar to the other monomer illustrated in the said (meth) acrylic-type polymer block (B), for example is mentioned. Only 1 type may be used for this other monomer, and 2 or more types may be used for it.

  As an upper limit of the usage-amount of the other monomer with respect to the sum total of the said (meth) acrylic acid ester and another monomer, 10 mol% is preferable and 5 mol% is more preferable. When the use amount is not more than the upper limit, the curing rate of the adhesive and the adhesive strength after curing are improved.

  The monomer used in the second polymerization step is preferably dried in advance in the same manner as the monomer used in the first polymerization step.

  In the second polymerization step, one or more of tertiary organic aluminum compounds, Lewis bases, other additives and organic solvents may be added to the polymerization reaction system in the same manner as in the first polymerization step. The types of these components can be the same as those in the first polymerization step. In addition, the usage-amount of these components can be suitably used according to the kind of organic solvent, other various polymerization conditions, etc., and the method in particular of adding these components to a polymerization reaction system is not restrict | limited.

  Various conditions such as the reaction temperature of anionic polymerization in the second polymerization step can be the same as those in the first polymerization step.

  Further, in the second polymerization step, from the viewpoint of improving the stability of the polymerization terminal anion, after the first polymerization step, a step of anionic polymerization by adding a monomethacrylate ester, and then an anion polymerization by adding a monoacrylate ester It is preferable to provide a process.

  As said monomethacrylic acid ester, the thing similar to the monomethacrylic acid ester illustrated in the said (meth) acrylic-type polymer block (B) can be used. As said monoacrylic acid ester, the thing similar to the monoacrylic acid ester illustrated in the said (meth) acrylic-type polymer block (B) can be used. Each of these monomethacrylic acid esters and monoacrylic acid esters may be used alone or in combination of two or more.

(Third polymerization step)
In the third polymerization step, after the second polymerization step, a monomer containing an active energy ray-curable monomer and containing a (meth) acrylic monomer is added, and anionic polymerization is performed. . As a result, a new (meth) acrylic polymer block (A) is formed in the polymer produced in the second polymerization step, and (meth) acrylic is formed at both ends of one (meth) acrylic polymer block (B). It is possible to easily and reliably obtain a triblock copolymer in which each one of the polymer block (A) is bonded.

  Examples of the monomer used in the third polymerization step include the same monomers as those used in the first polymerization step, and redundant description is omitted here. The monomer used in the third polymerization step may be the same as or different from the monomer used in the first polymerization step.

  In the third polymerization step, one or more of tertiary organic aluminum compounds, Lewis bases, other additives, and organic solvents may be added to the polymerization reaction system. The types of these components can be the same as those in the first polymerization step. In addition, the usage-amount of these components can be suitably used according to the kind of organic solvent, other various polymerization conditions, etc., and the method in particular of adding these components to a polymerization reaction system is not restrict | limited.

  Various conditions such as the reaction temperature of anionic polymerization in the third polymerization step can be the same as those in the first polymerization step.

  Anionic polymerization can be stopped by adding a polymerization terminator such as a protic compound to the reaction mixture after passing through the second polymerization step, and optionally the third polymerization step. Examples of the protic compound include methanol, a methanol solution of acetic acid, a methanol solution of hydrogen chloride, an aqueous solution of acetic acid, an aqueous solution of hydrogen chloride, and the like. As a usage-amount of a polymerization terminator, the range of 1 mol or more and 100 mol or less is preferable with respect to 1 mol of organolithium compounds.

  As a method for separating and obtaining the (meth) acrylic polymer (X) from the reaction mixture after the anionic polymerization is stopped, a known method can be adopted. As a method for separating and obtaining the (meth) acrylic polymer (X), for example, the reaction mixture is poured into a poor solvent of the (meth) acrylic polymer (X) and the (meth) acrylic polymer (X). And a method of obtaining the (meth) acrylic polymer (X) by distilling off the organic solvent from the reaction mixture.

  When the metal component derived from the organolithium compound and the tertiary organoaluminum compound remains in the obtained (meth) acrylic polymer (X), physical properties such as strength after curing of the adhesive are lowered. In some cases, poor transparency may occur. For this reason, it is preferable to remove the metal component derived from the organolithium compound and the tertiary organoaluminum compound after the anionic polymerization is stopped. Examples of the method for removing the metal component include a washing treatment using an acidic aqueous solution, an adsorption treatment using an adsorbent such as an ion exchange resin, celite, and activated carbon. Examples of the acidic aqueous solution include hydrochloric acid, sulfuric acid aqueous solution, nitric acid aqueous solution, acetic acid aqueous solution, propionic acid aqueous solution, and citric acid aqueous solution.

  According to the method for producing the (meth) acrylic polymer (X), a (meth) acrylic polymer (X) having a narrow molecular weight distribution is usually obtained, and the molecular weight distribution (Mw / Mn) is 1.5. The following (meth) acrylic polymers (X) can be produced.

[Compound (Y)]
The compound (Y) is a compound having an active energy ray curable group, and is a compound other than the (meth) acrylic polymer (X). The active energy ray-curable group of the compound (Y) is bonded to the (meth) acrylic polymer (X) and cured, or the compound (Y) is cured alone and the (meth) acrylic polymer (X ) And an intertwined network structure (interpenetrating polymer network (IPN)), etc., and the adhesive strength and curing speed between the film containing polyvinyl alcohol and the substrate are excellent, and the warpage is reduced. It is considered to be an adhesive capable of obtaining a bonded adhesive.

  Examples of the compound (Y) include a styrene compound, a fatty acid vinyl, a compound having a group represented by the following formula (3), a compound having an oxirane ring, a compound having an oxetane ring, a vinyl ether, and an N-vinyl compound. It is done. A compound (Y) may be used individually by 1 type, and may use 2 or more types together. In addition, when a polyfunctional compound (Y) is used as at least a part of the compound (Y), it can act as a crosslinking agent, which is preferable.

In the above formula (3), R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, X ² represents an oxygen atom, a sulfur atom or —NR ⁶ —, where R ⁶ represents a hydrogen atom or a carbon number. 1 to 6 hydrocarbon groups are represented.

Examples of R ⁵ include a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, 2-methylbutyl group, and 3-methylbutyl. Group, 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3-methyl Alkyl groups such as pentyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, n-hexadecyl group, n-eicosyl group; cyclopropyl group, cyclobutyl group, cyclopentyl A cycloalkyl group such as a group, a cyclohexyl group and a cyclooctyl group; an aryl group such as a phenyl group and a naphthyl group. When R ⁵ is a hydrocarbon group, the upper limit of the carbon number is preferably 10, and more preferably 4.

Further, a hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵ may have a substituent. The substituent is not particularly limited as long as it does not hinder the active energy ray curability of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, or a t-butoxy group; a chlorine atom And halogen atoms such as bromine atom.

R ⁵ is particularly preferably a hydrogen atom or a methyl group from the viewpoint of availability of the compound (Y) and excellent curing rate.

Examples of the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁶ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Group, 2-methylbutyl group, 3-methylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, neopentyl group, n-hexyl group Alkyl groups such as 2-methylpentyl group and 3-methylpentyl group; cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group; and aryl groups such as phenyl group.

Further, the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁶ may have a substituent. The substituent is not particularly limited as long as it does not hinder the active energy ray curability of the active energy ray curable group. For example, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, or a t-butoxy group; a chlorine atom And halogen atoms such as bromine atom.

R ⁶ is preferably a methyl group or an ethyl group from the viewpoints of availability of the compound (Y) and excellent curing rate.

X ² is preferably an oxygen atom or —NR ⁶ —, more preferably an oxygen atom, from the viewpoint of excellent availability of compound (Y) and curing rate.

  Examples of the styrene compound include styrene, indene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-chloromethylstyrene, p-acetoxystyrene, divinylbenzene and the like. It is done.

  Examples of the fatty acid vinyl include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, and vinyl cinnamate.

  Examples of the compound having a group represented by the above formula (3) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth). N-butyl acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 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, lauryl (meth) acrylate, stearyl (meth) acrylate , Isostearyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (Meth) acrylic acid dicyclopentenyloxyethyl, (meth) acrylic acid 4-butylcyclohexyl, (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 2-hydroxybutyl 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, benzyl (meth) acrylate, (meta ) Phenoxyethyl acrylate, (Me ) Tetrahydrofurfuryl acrylate, polyethylene glycol monoester (meth) acrylate, polypropylene glycol monoester (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxy (meth) acrylate Polyethylene glycol, methoxypolypropylene glycol (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, 4-acryloylmorpholine, Trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (Meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol 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 end (meth) acrylic acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2- (2,3-dihydroxypropoxy) ethyl Isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, ethylene oxide or propylene of bisphenol A Di (meth) acrylate of diol as an adduct of oxide, di (meth) acrylate of diol as an adduct of hydrogenated bisphenol A or propylene oxide, and (meth) acrylate added to diglycidyl ether of bisphenol A And epoxy (meth) acrylate, (3-ethyloxetane-3-yl) (meth) acrylate, and the like.

  Moreover, as another example of the compound having a group represented by the above formula (3), for example, epoxy (meth) acrylate type such as bisphenol A type epoxy acrylate resin, phenol novolac type epoxy acrylate resin, cresol novolak type epoxy acrylate resin, etc. Resin; Carboxyl group-modified epoxy (meth) acrylate resin; Urethane (meth) acrylate resin obtained by reacting urethane resin obtained from polyol and organic isocyanate with hydroxyl-containing (meth) acrylic acid ester; Ester bond to polyol (Meth) acryloyl group introduced resin; polyester (meth) acrylate resin; (meth) acrylamide compound such as N-hydroxyethyl (meth) acrylamide.

  Examples of the polyol include 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 poly And isobutylene.

  Examples of the organic isocyanate include tolylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate.

  Examples of the hydroxyl group-containing (meth) acrylic acid ester include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and pentaerythritol triacrylate.

  Examples of the compound having an oxirane ring include dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis (3,4 -Epoxycyclohexylmethyl) adipate, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, polytetramethylene glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, epoxidized vegetable oil, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- Lysidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, polybutadiene diglycidyl ether of hydroxyl groups at both ends, internal epoxidized product of polybutadiene, compound in which double bond of styrene-butadiene copolymer is partially epoxidized ("Epofriend" from Daicel Chemical Industries, Ltd.), compounds in which isoprene units of ethylene-butylene copolymer and polyisoprene block copolymer are partially epoxidized (such as "L-207" from KRATON), polyamide Examples include amine epichlorohydrin.

Examples of the compound having an oxetane ring include alkoxyalkyl group-containing monofunctional oxetanes such as 3-ethyl-3-hydroxymethyloxetane and 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, and 3-ethyl-3. -Aromatic group-containing monofunctional oxetane such as phenoxymethyloxetane, xylylenebisoxetane, 1,4-bis [(3-ethyloxetane-3-yl) methoxymethyl] benzene, 1,4-bis [(3-ethyl Oxetane-3-yl) methoxy] benzene, 1,3-bis [(3-ethyloxetane-3-yl) methoxy] benzene, 1,2-bis [(3-ethyloxetane-3-yl) methoxy] benzene, 4,4′-bis [(3-ethyloxetane-3-yl) methoxy] biphenyl, 2,2′-bis [(3- Tyloxetane-3-yl) methoxy] biphenyl, 3,3 ′, 5,5′-tetramethyl-4,4′-bis [(3-ethyloxetane-3-yl) methoxy] biphenyl, 2,7-bis [(3-Ethyloxetane-3-yl) methoxy] naphthalene, bis [4-{(3-ethyloxetane-3-yl) methoxy} phenyl] methane, bis [2-{(3-ethyloxetane-3-yl ) Methoxy} phenyl] methane, 2,2-bis [4-{(3-ethyloxetane-3-yl) methoxy} phenyl] propane, ether of novolac type phenol-formaldehyde resin with 3-chloromethyl-3-ethyloxetane modifications thereof, 3 (4), 8 (9) - bis [(3-ethyloxetan-3-yl) methoxymethyl] - tricyclo [5.2.1.0 ^{, 6]} decane, 2,3-bis [(3-ethyloxetan-3-yl) methoxymethyl] norbornane, 1,1,1-tris [(3-ethyloxetan-3-yl) methoxymethyl] propane, 1 -Butoxy-2,2-bis [(3-ethyloxetane-3-yl) methoxymethyl] butane, 1,2-bis [{2- (3-ethyloxetane-3-yl) methoxy} ethylthio] ethane, bis [{4- (3-ethyloxetane-3-yl) methylthio} phenyl] sulfide, 1,6-bis [(3-ethyloxetane-3-yl) methoxy] -2,2,3,3,4,4 , 5,5-octafluorohexane, 3-[(3-ethyloxetane-3-yl) methoxy] propyltrimethoxysilane, 3-[(3-ethyloxetane-3-yl) methoxy Hydrolysis condensate of propyltriethoxysilane, 3-[(3-ethyloxetane-3-yl) methoxy] propyltrialkoxysilane, condensate of tetrakis [(3-ethyloxetane-3-yl) methyl] silicate, etc. Can be mentioned.

  Examples of the vinyl ether include cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, dodecyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, and the like.

  Examples of the N-vinyl compound include N-vinylpyrrolidone and N-vinylmorpholine.

  Among these, the compound (Y) has a compound having a group represented by the above formula (3), a compound having an oxirane ring, and an oxetane ring from the viewpoints of handleability, reactivity and adhesiveness. At least one selected from the group consisting of compounds is preferable, and tetrahydrofurfuryl (meth) acrylate, 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, tris (2-hydroxyethyl) isocyanurate tri (meta) ) Acrylate is more preferred. Adhesiveness with adhesive obtained by using radical reactive compounds such as compounds having the group represented by the above formula (3) as compound (Y) and the base material of the cured product after curing the compound is improved. Tend to. Adhesion with an adhesive obtained by using a cation-reactive compound such as a compound having an oxirane ring or a compound having an oxetane ring as the compound (Y) or a film containing polyvinyl alcohol as a cured product after curing thereof Tend to improve. From the viewpoint of improving the adhesion to both the substrate and the film containing polyvinyl alcohol, it is preferable to use both a radical-reactive compound and a cation-reactive compound as the compound (Y), particularly the above formula (3). It is more preferable to use a compound having a group represented by the following: a compound having an oxirane ring and / or a compound having an oxetane ring.

  Further, from the viewpoint of bonding the active energy ray-curable group of the (meth) acrylic polymer (X) and the compound (Y), the active energy ray-curable property of the (meth) acrylic polymer (X). When the group is a radical reactive group, it is preferable that at least a part of the compound (Y) is a radical reactive compound, and the active energy ray curable group of the (meth) acrylic polymer (X) is When it is a cation reactive group, it is preferable that at least a part of the compound (Y) is a cation reactive compound. Specifically, when the active energy ray-curable group of the (meth) acrylic polymer (X) is a group having a group represented by the above formula (1), at least a part of the compound (Y) is the above. A compound having a group represented by the formula (3) is preferred, and the active energy ray-curable group of the (meth) acrylic polymer (X) is a group having an oxirane ring and / or a group having an oxetane ring. In this case, at least a part of the compound (Y) is preferably a compound having an oxirane ring and / or a compound having an oxetane ring.

  As a minimum of the content rate of compound (Y) in the adhesive (1), 10 mass% is preferred, 30 mass% is more preferred, and 50 mass% is still more preferred. On the other hand, the upper limit of the content is preferably 99% by mass, more preferably 95% by mass, further preferably 90% by mass, and the content is 85% by mass or less, 80% by mass or less, and further 75% by mass. It is good also as follows. When the content is equal to or higher than the lower limit, the viscosity of the adhesive can be appropriately maintained, and handleability is improved. On the other hand, when the content is less than or equal to the upper limit, mechanical properties such as adhesive strength of the adhesive are further improved.

[Active energy ray polymerization initiator (P)]
The adhesive (1) preferably further contains an active energy ray polymerization initiator (P) in addition to the (meth) acrylic polymer (X) and the compound (Y). The active energy ray polymerization initiator (P) can promote the reaction of the (meth) acrylic polymer (X) and the compound (Y) contained in the adhesive by irradiating the active energy ray. Examples of such an active energy ray polymerization initiator (P) include a compound that generates radicals by irradiation with active energy rays (radical polymerization initiator (R)), a compound that generates cations (cationic polymerization initiator ( C)), a compound capable of generating a base, and may be appropriately selected according to the type of the (meth) acrylic polymer (X) and the compound (Y) used.

  Examples of the radical polymerization initiator (R) include carbonyl compounds such as acetophenones, benzophenones, Michler ketones, and benzoins; sulfur compounds such as tetramethylthiuram monosulfide and thioxanthone. These radical polymerization initiators (R) may be used alone or in combination of two or more.

  Examples of the acetophenones include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the like. It is done.

  Examples of the benzophenones include benzophenone, benzoylbenzoic acid, hydroxybenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, acrylated benzophenone, and the like.

  Examples of the benzoins include benzoin, benzoin methyl ether, and benzoin isopropyl ether.

  Among these, as the radical polymerization initiator (R), acetophenones or benzophenones are preferable in terms of reactivity and transparency, and 1-hydroxycyclohexyl phenyl ketone is more preferable.

  Commercially available products of the above radical polymerization initiator (R) include, for example, “IRGACURE 184” (1-hydroxycyclohexyl phenyl ketone; manufactured by BASF), “Sorbastron BIPE” (manufactured by Kurokin Kasei), “Sorbaslon BIBE” (Kurokin Kasei) ), “IRGACURE 651” (2,2-dimethoxy-1,2-diphenylethane-1-one; manufactured by BASF), “DAROCUR 1173” (2-hydroxy-2-methyl-1-phenylpropane-1-one) ; BASF), “IRGACURE 2959” (BASF), “IRGACURE 127” (BASF), “IRGACURE 907” (BASF), “IRGACURE 369” (BASF), “KAYACURE BP” (Nippon Kayaku) ), "IRGACURE 379" BASF), “DAROCUR TPO” (BASF), “IRGACURE 819” (BASF), “IRGACURE 819DW” (BASF), “IRGACURE 784” (BASF), “IRGACURE OXE 01” (BASF), “IRGACURE OXE 02” (BASF), “IRGACURE 754” (BASF), “IRGACURE 500” (BASF), “IRGACURE 1800” (BASF), “IRGACURE 1870” (BASF), “DAROCUR 4265” (Manufactured by BASF), “KAYACURE DETX-S” (manufactured by Nippon Kayaku), “ESACURE KIP 150” (manufactured by Lamberti), “S-121” (manufactured by Shinko Giken), “Sake All BE” E "(manufactured by Seiko Chemical) and the like.

  Examples of the cationic polymerization initiator (C) include onium salt initiators such as sulfonium salt initiators and iodonium salt initiators, sulfonic acid derivatives, carboxylic acid esters, aryldiazonium salts, iron arene complexes, and pyridinium salts. , Quinolinium salts, O-nitrobenzyl group-containing compounds, and the like. These cationic polymerization initiators (C) may be used alone or in combination of two or more.

  Examples of the sulfonium salt initiator include p-hydroxyphenylbenzylmethylsulfonium salts such as p-phenylbenzylmethylsulfonium salt, p-phenyldimethylsulfonium salt, benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate, and triphenylsulfonium. Salts, triarylsulfonium salts such as diphenyl-4- (phenylthio) phenylsulfonium salt, diphenyl-4-thiophenoxyphenylsulfonium salt, 4,4-bis [di (β-hydroxyethoxy) phenylsulfonio] phenisulfide bishexa Examples thereof include disulfonium salts having a bis [4- (diphenylsulfonio) phenyl] sulfide skeleton such as fluoroantimonate.

Examples of the counter anion of these sulfonium salts include SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ^{− and the} like. Among these, PF ₆ ⁻ and SbF ₆ ⁻ are preferable from the viewpoint of reactivity and stability. preferable.

  Examples of the iodonium salt initiator include iodonium salts such as diphenyliodonium, bis (4-tert-butylphenyl) iodonium, (4-tert-butoxyphenyl) phenyliodonium, and (4-methoxyphenyl) phenyliodonium. It is done.

  Among these, the cationic polymerization initiator (C) is preferably a triarylsulfonium salt such as diphenyl-4- (phenylthio) phenylsulfonium salt or diphenyl-4-thiophenoxyphenylsulfonium salt from the viewpoint of thermal stability. .

  Examples of commercially available products of the cationic polymerization initiator (C) include “CPI-100P” (manufactured by San Apro), “CPI-101A” (manufactured by San Apro), “IRGACURE 250” (manufactured by BASF), “Adekaoptomer SP- 172 ”(manufactured by ADEKA),“ Adeka optomer SP-170 ”(manufactured by ADEKA),“ Adeka optomer SP-152 ”(manufactured by ADEKA),“ Adeka optomer SP-150 ”(manufactured by ADEKA),“ Sun Aid SI- ” 60L "(manufactured by Sanshin Chemical Industry)," Sun Aid SI-80L "(manufactured by Sanshin Chemical Industry)," Sun Aid SI-100L "(manufactured by Sanshin Chemical Industry)," Sun Aid SI-150L "(manufactured by Sanshin Chemical Industry) ) And the like.

  The lower limit of the amount of the active energy ray polymerization initiator (P) with respect to 100 parts by mass of the (meth) acrylic polymer (X) in the adhesive (1) is preferably 0.01 parts by mass, and 0.05 parts by mass. Is more preferable, 0.1 part by mass is more preferable, 1 part by mass, 3 parts by mass, and further 5 parts by mass may be sufficient. On the other hand, the upper limit of the amount is preferably 50 parts by weight, more preferably 40 parts by weight, and may be 20 parts by weight, 10 parts by weight, or even 8 parts by weight. When the amount is not less than the lower limit, the curing rate of the adhesive and the adhesive strength after curing are improved. On the other hand, when the amount is not more than the above upper limit, lowering of the molecular weight of the cured product due to excessively high curing speed is suppressed, and heat resistance is improved.

[Other optional ingredients]
The adhesive (1) may further contain other components other than the (meth) acrylic polymer (X), the compound (Y) and the active energy ray polymerization initiator (P). Examples of the other components include a crosslinking agent, a sensitizer, a diluent, a tackifier, a softener, a filler, a stabilizer, a pigment, and a dye. The other component may be an organic compound or an inorganic compound.

(Crosslinking agent)
The cross-linking agent cross-links the (meth) acrylic polymer (X), the compound (Y), and the like, thereby increasing the post-curing strength of the adhesive and the adhesive strength between the film containing polyvinyl alcohol and the substrate. Can be improved. Moreover, the said crosslinking agent may use only 1 type and may use 2 or more types together.

  Examples of the crosslinking agent include nitrogen compounds such as polyoxazoline, isocyanate compounds such as diphenylmethane diisocyanate, aldehyde compounds such as glutaraldehyde, zirconium compounds such as ammonium zirconium carbonate, and titanium compounds such as titanium lactate.

  As an upper limit of the content rate of the crosslinking agent in the said adhesive agent, 20 mass% is preferable and 15 mass% is more preferable. On the other hand, as a minimum of the above-mentioned content rate, 1 mass% is preferred and 3 mass% is more preferred. When the content is not more than the above upper limit, the viscosity of the adhesive can be appropriately maintained, and the handleability is improved.

(Sensitizer)
The sensitizer promotes curing of the adhesive by moving or expanding the sensitivity of the active energy ray. Examples of such a sensitizer include n-butylamine, di-n-butylamine, tri-n-butylphosphine, allylthiouric acid, triethylamine, and the like, and triethylamine is preferable.

  The sensitizer is preferably used in combination with the active energy ray polymerization initiator (P). When the sensitizer and the active energy ray polymerization initiator (P) are used in combination, the lower limit of the mass ratio of the sensitizer to the total of the active energy ray polymerization initiator (P) and the sensitizer is preferably 10%, 20% is more preferable. On the other hand, the upper limit of the mass ratio is preferably 90%, more preferably 80%.

(Diluent)
The diluent is added to the adhesive to adjust the viscosity of the adhesive and the mechanical strength after the adhesive is cured. Examples of the diluent include compounds having no active energy ray-curable group. Specifically, for example, phthalates, non-aromatic dibasic esters, aliphatic esters, polyalkylene glycol esters, phosphorus Obtained by polymerizing acid-based esters, trimellitic acid esters, chlorinated paraffin, hydrocarbon-based oils, process oils, polyethers, dibasic acids and dihydric alcohols, polyester-based plasticizers, and vinyl-based monomers A vinyl polymer etc. are mentioned. These inactive compounds may be used individually by 1 type, and may use 2 or more types together. The diluent may have a functional group (hydroxyl group, carboxyl group, halogen group, etc.) other than the active energy ray-curable group.

  Examples of the phthalic acid esters include dibutyl phthalate, diheptyl phthalate, di (2-ethylhexyl) phthalate, and butyl benzyl phthalate.

  Examples of the non-aromatic dibasic acid ester include dioctyl adipate, dioctyl sebacate, dibutyl sebacate, and isodecyl succinate.

  Examples of the aliphatic ester include butyl oleate and methyl acetylricinoleate.

  Examples of the polyalkylene glycol ester include diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester.

  Examples of the phosphoric acid esters include tricresyl phosphate and tributyl phosphate.

  Examples of the hydrocarbon oil include alkyl diphenyl and partially hydrogenated terphenyl.

  Examples of the polyethers include polyether polyols; derivatives obtained by converting polyether polyol hydroxyl groups into ester groups, ether groups, and the like. Here, examples of the polyether polyol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

  Examples of the dibasic acid include sebacic acid, adipic acid, azelaic acid, and phthalic acid. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol.

  Examples of the vinyl polymer include (meth) acrylic polymer, polybutene, polyisobutylene, styrene polymer (polystyrene, poly-α-methylstyrene, etc.), diene polymer (polybutadiene, polychloroprene, etc.), Examples thereof include vinyl ether polymers and copolymers thereof (butadiene-acrylonitrile copolymers and the like).

  As the diluent, a polymer having a number average molecular weight (Mn) of 400 or more and 15,000 or less is preferable. As a minimum of Mn of the above-mentioned polymer, 800 is more preferred and 1,000 is still more preferred. On the other hand, the upper limit of Mn of the polymer is more preferably 10,000, and further preferably 8,000. When the Mn is equal to or more than the lower limit, it is possible to prevent the diluent from flowing out of the cured product after the adhesive is cured, and to maintain the initial physical properties for a long period. Moreover, the handleability of the said adhesive improves because the said Mn is below the said upper limit.

  The molecular weight distribution (Mw / Mn) when the diluent is a polymer is not particularly limited, but is usually less than 1.8, preferably 1.7 or less, more preferably 1.6 or less, and 1.5 or less. Is more preferable, 1.4 or less is particularly preferable, and 1.3 or less is most preferable.

  The diluent is preferably compatible with the (meth) acrylic polymer (X). When the diluent is a polymer, a vinyl polymer is more preferable from the viewpoint of compatibility, weather resistance, and heat resistance. A (meth) acrylic polymer is more preferable, and an acrylic polymer is particularly preferable.

  Examples of the acrylic polymer include poly (n-butyl acrylate) and poly (2-ethylhexyl acrylate). Examples of the synthesis method of the acrylic polymer include a solution polymerization method, a high temperature continuous polymerization method, and a living radical polymerization method.

  As a method for synthesizing the acrylic polymer, a high-temperature continuous polymerization method is preferable from the viewpoint that an acrylic polymer can be synthesized without using a solvent or a chain transfer agent. Examples of the high-temperature continuous polymerization method include methods described in USP 4414370, JP-A-59-6207, JP-B-5-58005, JP-A-1-313522, USP5010166, and the like. Examples of the acrylic polymer synthesized by such a high-temperature continuous polymerization method include Toagosei UP series (see the October 1999 issue of industrial materials).

  Moreover, as a method for synthesizing the acrylic polymer, a living radical polymerization method is preferable, and an atom transfer radical polymerization method is more preferable because a polymer having a narrow molecular weight distribution can be obtained and the viscosity of the adhesive can be reduced. .

  As a minimum of the usage-amount of a diluent with respect to 100 mass parts of (meth) acrylic-type polymer (X), 5 mass parts is preferable, 10 mass parts is more preferable, and 20 mass parts is further more preferable. On the other hand, the upper limit of the amount used is preferably 150 parts by mass, more preferably 120 parts by mass, and even more preferably 100 parts by mass. When the usage amount is equal to or more than the lower limit, the viscosity of the adhesive and the mechanical strength after the adhesive is cured can be more effectively adjusted. On the other hand, when the use amount is not more than the upper limit, the mechanical strength of the cured product is improved.

(Tackifier)
The tackifier imparts tackiness to the cured product after curing the adhesive. Examples of the tackifier include chroman / indene resin, phenol resin, pt-butylphenol / acetylene resin, phenol / formaldehyde resin, terpene resin, synthetic terpene resin, aromatic modified terpene resin, xylene / formaldehyde resin, aromatic carbonization. Hydrogen resin, aliphatic cyclic hydrocarbon resin, monoolefin or diolefin oligomer, hydrocarbon resin, hydrogenated hydrocarbon resin, polybutene, polyhydric alcohol ester of rosin, hydrogenated rosin, hydrogenated wood rosin, hydrogenated rosin and mono Examples thereof include esters with alcohol or polyhydric alcohol, terpine resins, and the like. Among these, terpene resins, synthetic terpene resins, aromatic modified terpene resins, aliphatic saturated petroleum resins, rosin esters, disproportionated rosin esters, hydrogenated rosin esters, aliphatic petroleum resins (C5 aliphatic resins) Petroleum resin, C5 / C9 aliphatic petroleum resin, etc.) or modified aliphatic petroleum resin is preferred.

[Method for producing adhesive (1)]
The said adhesive (1) mixes and stirs (meth) acrylic-type polymer (X), a compound (Y), and other arbitrary components (active energy ray polymerization initiator (P) and other arbitrary components). Can be easily manufactured.

<Adhesive (2)>
The adhesive (2) is an adhesive for bonding a film containing polyvinyl alcohol and a substrate, and includes a polymer (X ′) having an active energy ray-curable group and a polymer (X ′). The crosslinking density obtained from the storage elastic modulus of the rubber-like flat region obtained by measuring the dynamic viscoelasticity after curing is 0.4 mol / L. The above is 2 mol / L or less.

  Since the adhesive (2) has a cross-linking density after curing in a specific range, it is excellent in the balance between the adhesion to the film containing polyvinyl alcohol and the substrate and the strength of the cured product of the adhesive itself, It is considered that an adhesive body with improved adhesive strength and reduced warpage can be obtained, and the curing speed is also excellent.

  The lower limit of the crosslinking density is preferably 0.5 mol / L, more preferably 1 mol / L, further preferably 1.3 mol / L, particularly preferably 1.4 mol / L, and most preferably 1.5 mol / L. Moreover, as an upper limit of the said crosslinking density, 1.9 mol / L is preferable, 1.8 mol / L is more preferable, 1.7 mol / L is further more preferable, 1.6 mol / L is especially preferable. When the crosslinking density is equal to or higher than the lower limit, the strength of the cured product itself after the adhesive is cured is improved. On the other hand, when the crosslinking density is less than or equal to the above upper limit, the adhesiveness to a film containing polyvinyl alcohol and a substrate is improved and bonded due to improved deformation followability of the obtained cured product. Body warpage is further reduced. In addition, the said crosslinking density raises the content rate of the active energy ray-curable group in a polymer (X '), for example, or makes the content rate of the polyfunctional compound in a compound (Y') high. , Can increase its value.

The crosslink density is determined from the storage elastic modulus of the rubber-like flat region obtained by performing dynamic viscoelasticity measurement on the cured product after curing the adhesive. That is, the storage elastic modulus (E ′: unit is Pa) and the desired crosslink density (ν: unit is mol / m ³ ) are E ′ = 3νRT (where R represents a gas constant, and T is an absolute temperature ( The unit can be considered to satisfy the relationship of K)), and can be calculated from the relationship. The storage modulus of the cured product is, for example, 24% at a temperature of 23 ° C. and a relative humidity of 50% by applying an adhesive onto a release-treated base film and irradiating with ultraviolet rays so as to be 700 mJ / cm ^2. After being left for a period of time, it can be measured using a dynamic viscoelasticity measuring device on a cured sample obtained by peeling off from the base film, specifically, the method described in the examples Can be measured. The rubber-like flat region can be obtained from a graph showing the relationship between the measurement temperature and the storage elastic modulus. In particular, when the glass transition point (Tg) of the cured product is sufficiently smaller than 120 ° C., the crosslinking density is It can be obtained from the above equation using the value of the storage elastic modulus at 150 ° C.

The adhesive (2) has a storage elastic modulus at 150 ° C. obtained by the above dynamic viscoelasticity measurement of 4 × 10 ⁶ Pa to 21 × 10 ⁶ Pa, and a film and a substrate containing polyvinyl alcohol It is preferable from the viewpoints of improving the adhesion to the substrate and reducing the warpage of the obtained adhesive. The lower limit of the storage elastic modulus of the 0.99 ° C., preferably from 6 × ¹⁰ 6 Pa, more preferably ¹⁰ × 10 6 Pa, more preferably 14 × ¹⁰ 6 Pa, particularly preferably from ^{15 × 10 6 Pa, 16 ×} 10 ⁶ Pa is most preferred. The upper limit of the storage elastic modulus at 150 ° C. is preferably 20 × 10 ⁶ Pa, more preferably 19 × 10 ⁶ Pa, still more preferably 18 × 10 ⁶ Pa, and more preferably 17 × 10 ⁶ Pa. When the storage elastic modulus at 150 ° C. is equal to or higher than the lower limit, the strength of the cured product itself after the adhesive is cured is improved. On the other hand, when the crosslinking density is less than or equal to the above upper limit, the adhesiveness to a film containing polyvinyl alcohol and a substrate is improved and bonded due to improved deformation followability of the obtained cured product. Body warpage is further reduced. The storage elastic modulus at 150 ° C. is, for example, increasing the content ratio of the active energy ray-curable group in the polymer (X ′) or increasing the content ratio of the polyfunctional compound in the compound (Y ′). The value can be increased.

  The polymer (X ′) is not particularly limited as long as it has an active energy ray-curable group, and a preferable example thereof is the (meth) acrylic polymer (X) ( For example, a (meth) acrylic polymer (acrylic resin (meth) acrylate etc.) having a (meth) acryloyloxy group at the terminal and / or side chain, and a more preferred example having an active energy ray-curable group (meth) And a block copolymer having an acrylic polymer block (A) and a (meth) acrylic polymer block (B) substantially free of an active energy ray-curable group.

  Another preferred example of the polymer (X ′) is urethane (meth) acrylate. There is no restriction | limiting in particular in the kind of the said urethane (meth) acrylate, Urethane (meth) acrylates, such as a polyester type, a polyether type, and a polycarbonate type, can be used. General urethane (meth) acrylates usually have a (meth) acryloyl group at the end of the polymer chain, and the content of active energy ray-curable groups is relatively low. It is preferable to increase the content of the polyfunctional compound in '). The explanation of the active energy ray-curable group that the polymer (X ′) has is the same as the explanation of the active energy ray-curable group that the (meth) acrylic polymer (X) has in the adhesive (1). .

  The number average molecular weight (Mn) of the polymer (X ′) is not particularly limited, but the lower limit of the Mn is 1,000 from the viewpoint of handling property, fluidity, mechanical properties and the like of the polymer (X ′). Preferred is 2,000, more preferred is 2,500, more preferred is 4,000, particularly preferred is 4,000, most preferred is 5,000, and the number average molecular weight (Mn) is a polymer (X ') of 7,000 or more. Can also be preferably used. On the other hand, the upper limit of Mn is preferably 7,000,000, more preferably 3,000,000, and 2,000,000 from the viewpoint of suppressing the increase in viscosity during the preparation of the obtained adhesive and its preparation. Is more preferable.

  The lower limit of the content of the polymer (X ′) in the adhesive (2) is preferably 1% by mass, more preferably 3% by mass, further preferably 5% by mass, particularly preferably 10% by mass, and the above content The rate may be 15% by mass or more. On the other hand, the upper limit of the content is preferably 90% by mass, more preferably 70% by mass, and particularly preferably 50% by mass. When the content is equal to or higher than the lower limit, an adhesive body in which mechanical properties such as adhesive strength of the adhesive are further improved and warpage is further reduced can be obtained. On the other hand, when the content is less than or equal to the above upper limit, the viscosity of the adhesive can be appropriately maintained, and the handleability is improved.

  The compound (Y ′) is a compound having an active energy ray-curable group other than the polymer (X ′), and corresponds to the polymer (X ′) among the compounds (Y) described above in the adhesive (1). The thing which does not do is mentioned. Although there is no restriction | limiting in particular in the molecular weight of a compound (Y '), From a viewpoint of the improvement of the adhesiveness to the film and base material containing polyvinyl alcohol, reduction of the curvature of the adhesive body obtained, the said molecular weight is less than 4,000. Is preferable, less than 2,000 is more preferable, and less than 1,000 is more preferable.

  From the viewpoint of bonding the active energy ray-curable group of the polymer (X ′) and the compound (Y ′), the active energy ray-curable group of the polymer (X ′) is a radical reactive group. In this case, at least a part of the compound (Y ′) is preferably a radical-reactive compound. When the active energy ray-curable group of the polymer (X ′) is a cation-reactive group, the compound (Y It is preferable that at least a part of ') is a cation-reactive compound. Specifically, when the active energy ray-curable group of the polymer (X ′) is a group having a group represented by the above formula (1), at least a part of the compound (Y ′) is represented by the above formula (3). In the case where the active energy ray-curable group of the polymer (X ′) is a group having an oxirane ring and / or a group having an oxetane ring, the compound (Y It is preferable that at least a part of ') is a compound having an oxirane ring and / or a compound having an oxetane ring.

  As a minimum of the content rate of compound (Y ') in the adhesive (2), 10 mass% is preferred, 30 mass% is more preferred, and 50 mass% is still more preferred. On the other hand, the upper limit of the content is preferably 99% by mass, more preferably 95% by mass, further preferably 90% by mass, and the content is 85% by mass or less, 80% by mass or less, and further 75% by mass. It is good also as follows. When the content is equal to or higher than the lower limit, the viscosity of the adhesive can be appropriately maintained, and handleability is improved. On the other hand, when the content is less than or equal to the upper limit, mechanical properties such as adhesive strength of the adhesive are further improved.

  It is preferable that the adhesive (2) further contains an active energy ray polymerization initiator (P) in addition to the polymer (X ′) and the compound (Y ′) as in the adhesive (1). The description of the active energy ray polymerization initiator (P) in the adhesive (2) is the same as the description of the active energy ray polymerization initiator (P) in the adhesive (1).

  The lower limit of the amount of the active energy ray polymerization initiator (P) relative to 100 parts by mass of the polymer (X ′) in the adhesive (2) is preferably 0.01 parts by mass, more preferably 0.05 parts by mass. 1 part by mass is more preferable, and 1 part by mass, 3 parts by mass, and further 5 parts by mass may be used. On the other hand, the upper limit of the amount is preferably 50 parts by weight, more preferably 40 parts by weight, and may be 20 parts by weight, 10 parts by weight, or even 8 parts by weight. When the amount is not less than the lower limit, the curing rate of the adhesive and the adhesive strength after curing are improved. On the other hand, when the amount is not more than the above upper limit, lowering of the molecular weight of the cured product due to excessively high curing speed is suppressed, and heat resistance is improved.

  In the adhesive (2) as well as the adhesive (1), other components (for example, a crosslinking agent and a sensitizer) other than the polymer (X ′), the compound (Y ′) and the active energy ray polymerization initiator (P). , Diluents, tackifiers, softeners, fillers, stabilizers, pigments, dyes, etc.). The description of the other components (other optional components) in the adhesive (2) is the same as the description of the other components (other optional components) in the adhesive (1).

  The adhesive (2) can be easily prepared by mixing and stirring the polymer (X ′), the compound (Y ′) and other optional components (active energy ray polymerization initiator (P) and other optional components). Can be manufactured.

[PVA film]
The adhesive of this invention is for adhere | attaching the film (PVA film) containing polyvinyl alcohol, and a base material. Examples of the polyvinyl alcohol (PVA) contained in the PVA film include those obtained by saponifying a polyvinyl ester obtained by polymerizing a vinyl ester. The polyvinyl ester may be obtained by polymerizing only a vinyl ester or may be obtained by copolymerizing a vinyl ester and another monomer copolymerizable therewith. However, it is preferable that it is obtained by polymerizing only vinyl ester. Only 1 type may be used for the said vinyl ester and it may use 2 or more types together, It is preferable to use only 1 type.

Examples of the vinyl ester include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, and isopropenyl acetate. The vinyl ester is preferably a compound having a vinyloxycarbonyl group (H ₂ C═CH—O—CO—) in the molecule from the viewpoint of ease of production, availability, and cost of PVA. Vinyl is more preferred.

  Examples of other monomers copolymerizable with the vinyl ester include, for example, α-olefins having 2 to 30 carbon atoms, (meth) acrylic acid, (meth) acrylate, (meth) acrylate, (meth). Acrylamide, (meth) acrylamide derivatives, N-vinylamide, vinyl ether, vinyl methacrylate, vinyl halide, allyl compound, maleic acid, maleate, maleic acid ester, maleic acid anhydride, itacone Examples thereof include acids, itaconic acid salts, itaconic acid esters, itaconic acid anhydrides, vinylsilyl compounds such as vinyltrimethoxysilane, unsaturated sulfonic acids, and unsaturated sulfonic acid salts.

  Examples of the α-olefin having 2 to 30 carbon atoms include ethylene, propylene, 1-butene, and isobutene.

  Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and (meth) acrylic acid n-. Examples include butyl, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, and the like.

  Examples of the (meth) acrylamide derivative include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, diacetone (meth) acrylamide, (meth) acrylamide propanesulfonic acid or The salt, (meth) acrylamide propyl dimethylamine or its salt, N-methylol (meth) acrylamide or its derivative is mentioned.

  Examples of the N-vinylamide include N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone and the like.

  Examples of the vinyl ether include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether and the like.

  Examples of the vinyl halide include vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride.

  Examples of the allyl compound include allyl acetate and allyl chloride.

  The upper limit of the proportion of structural units derived from the other monomers in the polyvinyl ester is preferably 15 mol%, more preferably 10 mol%, based on the number of moles of all structural units constituting the polyvinyl ester, 5 mol% is more preferable.

  The PVA is preferably not graft-polymerized, but may be modified with a monomer that can be graft-polymerized as long as the effects of the present invention are not significantly impaired. The graft copolymerization may be performed on polyvinyl ester, or may be performed on PVA obtained by saponifying polyvinyl ester.

  Examples of the graft copolymerizable monomer include unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated sulfonic acid, unsaturated sulfonic acid derivative, α-olefin having 2 to 30 carbon atoms, and the like. . The graft copolymerizable monomer may be used alone or in combination of two or more. The proportion of structural units derived from the graft copolymerizable monomer in polyvinyl ester or PVA is preferably 5 mol% or less with respect to the number of moles of all structural units constituting the polyvinyl ester or PVA.

  A part of the hydroxyl groups of the PVA may be cross-linked. Moreover, a part of hydroxyl group which said PVA has may react with aldehyde compounds, such as acetaldehyde and a butyraldehyde, and may form an acetal structure.

  The lower limit of the saponification degree of PVA is preferably 99.0 mol%, more preferably 99.8 mol%, and even more preferably 99.9 mol% from the viewpoint of improving the heat and heat resistance of the PVA film. Here, the “degree of saponification of PVA” is a value measured according to JIS-K6726 (1994). Among structural units of PVA, structural units that can be converted into vinyl alcohol units by saponification (typically The ratio (mol%) of the number of moles of the vinyl alcohol unit to the total number of moles of the vinyl ester unit) and the vinyl alcohol unit.

  The degree of polymerization of the above PVA is not particularly limited, but the upper limit thereof is preferably 10,000, more preferably 8,000, and further preferably 5,000. On the other hand, the lower limit of the polymerization degree of the PVA is preferably 1,000, more preferably 1,500, and still more preferably 2,000. When the polymerization degree of the PVA is not more than the above upper limit, an increase in the production cost of the PVA can be suppressed, and process passability during film formation is improved. On the other hand, when the polymerization degree of the PVA is equal to or higher than the lower limit, for example, when the PVA film is processed into a polarizing film as described later, each performance such as polarization performance is improved. Here, the “degree of polymerization of PVA” means the average degree of polymerization measured according to the description of JIS-K6726 (1994).

  As an upper limit of the content rate of PVA in a PVA film, 100 mass% is preferable. On the other hand, as a minimum of the content rate of the above-mentioned PVA, 50 mass% is preferred, 80 mass% is more preferred, and 85 mass% is still more preferred.

  Examples of other components that the PVA film may contain include a plasticizer, a surfactant, an antioxidant, an antifreezing agent, a pH adjuster, a concealing agent, an anti-coloring agent, and an oil agent.

  The plasticizer is intended to improve the handleability and stretchability of the PVA film. Although it does not specifically limit as a plasticizer, A polyhydric alcohol is preferable. Examples of the polyhydric alcohol include ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, trimethylolpropane, etc. Among them, the stretchability of the PVA film is better. From this point, glycerin is more preferable. Only one type of plasticizer may be used, or two or more types may be used in combination.

  As an upper limit of content of the plasticizer with respect to 100 mass parts of PVA in a PVA film, 20 mass parts is preferable, 17 mass parts is more preferable, and 14 mass parts is further more preferable. On the other hand, as a minimum of content of the above-mentioned plasticizer, 3 mass parts are preferred, 5 mass parts are more preferred, and 7 mass parts are still more preferred. When the content of the plasticizer is not more than the above upper limit, the handleability of the PVA film is improved. On the other hand, when the content of the plasticizer is not less than the above lower limit, the stretchability of the PVA film is improved.

  The surfactant is intended to improve the film forming property and suppress the occurrence of uneven thickness of the PVA film in the case of producing a PVA film using a film-forming stock solution described later. Although the kind of surfactant is not specifically limited, From a viewpoint of film forming property, an anionic surfactant or a nonionic surfactant is preferable and a nonionic surfactant is more preferable. Only one surfactant may be used, or two or more surfactants may be used in combination.

  Examples of the anionic surfactant include carboxylic acid type surfactants such as potassium laurate, sulfate type surfactants such as octyl sulfate, and sulfonic acid type surfactants such as dodecylbenzene sulfonate.

  Nonionic surfactants include, for example, alkyl ether type surfactants such as polyoxyethylene oleyl ether, alkylphenyl ether type surfactants such as polyoxyethylene octylphenyl ether, and alkyl ester type surfactants such as polyoxyethylene laurate. Activators, alkylamine type surfactants such as polyoxyethylene lauryl amino ether, alkylamide type surfactants such as polyoxyethylene lauric acid amide, polypropylene glycol ether type surfactants such as polyoxyethylene polyoxypropylene ether, Examples include alkanolamide type surfactants such as lauric acid diethanolamide and oleic acid diethanolamide, and allyl phenyl ether type surfactants such as polyoxyalkylene allyl phenyl ether. It is.

  As an upper limit of content of surfactant with respect to 100 mass parts of PVA in a PVA film, 0.5 mass part is preferable and 0.3 mass part is more preferable. On the other hand, as a minimum of content of the above-mentioned surfactant, 0.01 mass part is preferred and 0.02 mass part is more preferred. When the content of the surfactant is not more than the above upper limit, the handleability of the PVA film is improved. On the other hand, film forming property improves because content of the said surfactant is more than the said minimum.

  Although it does not specifically limit as an upper limit of the thickness of a PVA film, 50 micrometers is preferable, 45 micrometers is more preferable, and 30 micrometers is further more preferable. On the other hand, although it does not specifically limit as a minimum of the thickness of a PVA film, 3 micrometers is preferable from a viewpoint of manufacturing a PVA film smoothly.

[PVA film production method]
The manufacturing method in particular of a PVA film is not restrict | limited, The manufacturing method from which the thickness and width | variety of the film after film forming become more uniform can be employ | adopted preferably, For example, the said PVA which comprises a PVA film, and as needed Furthermore, a film-forming stock solution in which one or two or more of a plasticizer, a surfactant, an antioxidant, an antifreezing agent, a pH adjusting agent, a concealing agent, an anti-coloring agent, an oil agent, etc. are dissolved in a liquid medium, PVA, and optionally further including one or more of a plasticizer, a surfactant, an antioxidant, an antifreeze agent, a pH adjuster, a concealing agent, an anti-coloring agent, an oil agent, etc. It can manufacture using the melt | dissolution film forming stock solution. When the film-forming stock solution contains optional components such as a plasticizer and a surfactant, it is preferable that these components are uniformly mixed.

  Examples of the liquid medium include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, glycerin, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane, ethylenediamine, and diethylenetriamine. Can be mentioned. Among these, water is preferable from the viewpoint of a small load on the environment and the point of recoverability. The liquid medium may be used alone or in combination of two or more.

  The content of volatile components such as liquid media removed by volatilization and evaporation during film formation in the film-forming stock solution (the volatile content of the film-forming stock solution) varies depending on the film-forming method, film-forming conditions, etc. Is preferably 95% by mass, more preferably 90% by mass, and still more preferably 85% by mass. On the other hand, the lower limit of the volatile fraction of the film-forming stock solution is preferably 50% by mass, more preferably 55% by mass, and still more preferably 60% by mass. When the volatile fraction of the film-forming stock solution is not more than the above upper limit, the concentration of the film-forming stock solution does not become too low, and the production of an industrial PVA film becomes easy. On the other hand, when the volatile fraction of the film-forming stock solution is not less than the above lower limit, the viscosity of the film-forming stock solution does not become too high, and filtration and defoaming are smoothly performed during the preparation of the film-forming stock solution. Manufacture of few PVA films becomes easy.

  Examples of the film forming method for forming a PVA film using the above film forming stock solution include a cast film forming method, an extrusion film forming method, a wet film forming method, a gel film forming method, and the like. The cast film forming method and the extrusion film forming method are preferable in that a PVA film having uniform and good physical properties can be obtained. Only 1 type may be employ | adopted for the said film forming method, and may be employ | adopted combining 2 or more types. The formed film can be dried or heat-treated as necessary.

  As an example of a specific method for producing a PVA film, for example, a T-type slit die, a hopper plate, an I-die, a lip coater die or the like is used to rotate the above-mentioned film forming stock solution on the most upstream side. The volatile component is uniformly discharged or cast on the peripheral surface of the first roll (or belt) and the volatile component is discharged from one surface of the film discharged or cast on the peripheral surface of the first roll (or belt). Evaporate to dry, then further dry on the circumference of one or more rotating heated rolls located downstream, or pass through a hot air dryer and further dry, The method of winding with a winding device can be preferably employed industrially. Drying with a heated roll and drying with a hot air dryer may be performed in an appropriate combination.

  By the production method as described above, a PVA film that is not substantially stretched (not subjected to a stretching step) can be easily obtained. This PVA film can be directly bonded to the substrate using the adhesive, but in the present invention, the PVA film to be bonded to the substrate by the adhesive is a stretched PVA film (stretched polyvinyl alcohol film). It is preferable to be an optical film such as a polarizing film or a retardation film.

[Production method of polarizing film]
The method for producing the polarizing film is not particularly limited. For example, the PVA film that is not substantially stretched is subjected to swelling, dyeing, stretching, and, if necessary, crosslinking treatment, fixing treatment, drying, heat treatment, and the like. The method of giving is mentioned. In this case, the order of each treatment such as swelling, dyeing, crosslinking treatment, stretching, and fixing treatment is not particularly limited, and one or two or more treatments can be performed simultaneously. Also, one or more of each process can be performed twice or more. Furthermore, when a dichroic dye is added to the film-forming stock solution in the film-forming process, the dyeing process can be omitted.

(Swelling)
Swelling can be performed by immersing the PVA film in water. The water is not limited to pure water, and may be an aqueous solution in which various components are dissolved, or a mixture of water and an aqueous medium. Examples of the aqueous medium include the same liquid medium as exemplified in the film-forming stock solution.

  As an upper limit of the temperature of the water at the time of immersing a PVA film in water, 40 degreeC is preferable, 38 degreeC is more preferable, and 35 degreeC is further more preferable. On the other hand, as a minimum of the temperature of the above-mentioned water, 20 ° C is preferred, 22 ° C is more preferred, and 25 ° C is still more preferred. Moreover, as an upper limit of time to immerse a PVA film in water, 5 minutes are preferable and 3 minutes are more preferable. On the other hand, as a minimum of time to immerse in the above-mentioned water, 0.5 minutes are preferred and 1 minute is more preferred.

(staining)
Dyeing can be performed by immersing the PVA film in an aqueous solution containing a dichroic dye. Examples of the dichroic dye include iodine dyes and dichroic organic dyes.

As the iodine dye, for example, _I ^{3 -,} _{I 5} -, and the like. These iodine dyes can be obtained, for example, by bringing iodine (I ₂ ) into contact with potassium iodide.

  Examples of the dichroic organic dye include direct black 17, 19, 154; direct brown 44, 106, 195, 210, 223; direct red 2, 23, 28, 31, 37, 39, 79, 81, 240, 242, 247; Direct Blue 1, 15, 22, 78, 90, 98, 151, 168, 202, 236, 249, 270; Direct Violet 9, 12, 51, 98; Direct Green 1, 85; Direct Yellow 8, 12, 44, 86, 87; Direct Orange 26, 39, 106, 107 and the like.

As the dichroic dye, iodine-based dyes are preferable from the viewpoints of handleability, availability, polarization performance, and the like. These dichroic dyes may be used alone, it may be used in combination of two or more, for example, I ₃ ^- may be a balanced mixture as ^- and I _5.

The density | concentration of the dichroic dye in the aqueous solution containing the said dichroic dye can be suitably set according to the kind etc. of the dichroic dye to be used, for example, can be 0.001 mass% or more and 1 mass% or less. When an iodine-potassium iodide aqueous solution is used as the aqueous solution containing the dichroic dye, the iodine (I ₂ ) concentration used is 0.01 because the iodine dye can be efficiently adsorbed to the PVA film. The concentration of potassium iodide (KI) used is preferably 0.01% by mass or more and 10% by mass or less.

  As an upper limit of the temperature of the aqueous solution containing the said dichroic dye, 50 degreeC is preferable and 40 degreeC is more preferable. On the other hand, as a minimum of the temperature of the above-mentioned aqueous solution, 20 ° C is preferred and 25 ° C is more preferred. By setting the temperature of the aqueous solution within the above range, the dichroic dye can be efficiently adsorbed to the PVA film.

(Crosslinking)
Crosslinking can be performed by immersing the PVA film in an aqueous solution containing a crosslinking agent. By this crosslinking, it is possible to effectively prevent PVA from eluting into water even when stretching is performed at a relatively high temperature and wet. For this reason, it is preferable to perform crosslinking before stretching.

  Examples of the crosslinking agent include boron compounds, and examples of the boron compounds include borates such as boric acid and borax. This crosslinking agent may use only 1 type and may use 2 or more types together. Moreover, the aqueous solution containing a crosslinking agent may contain adjuvants, such as potassium iodide.

  As an upper limit of the density | concentration of the crosslinking agent in the aqueous solution containing the said crosslinking agent, 15 mass% is preferable and 7 mass% is more preferable. On the other hand, the lower limit of the concentration of the crosslinking agent is preferably 1% by mass, and more preferably 2% by mass. As an upper limit of the temperature of the aqueous solution containing the said crosslinking agent, 50 degreeC is preferable and 40 degreeC is more preferable. On the other hand, as a minimum of the temperature of the above-mentioned aqueous solution, 20 ° C is preferred and 25 ° C is more preferred.

(Pre-stretch)
Apart from the stretching step described below, the PVA film can be stretched simultaneously with one or more of the treatments such as swelling, dyeing and crosslinking. By performing such stretching (pre-stretching), wrinkles can be prevented from entering the PVA film. The draw ratio of the pre-stretching is preferably 4 times or less, more preferably 3.5 times or less, based on the original length of the PVA film before stretching, from the viewpoint of the polarizing performance of the obtained polarizing film. 5 times or more is preferable.

  Moreover, regarding the draw ratio in each treatment, the upper limit of the draw ratio during swelling is preferably 3 times, more preferably 2.5 times, and even more preferably 2.3 times. On the other hand, the lower limit of the draw ratio is preferably 1.1 times, more preferably 1.2 times, and even more preferably 1.4 times.

  The upper limit of the draw ratio during dyeing is preferably 2 times, more preferably 1.8 times, and even more preferably 1.5 times. On the other hand, the lower limit of the draw ratio is preferably 1.1 times.

  The upper limit of the draw ratio at the time of crosslinking is preferably 2 times, more preferably 1.5 times, and further preferably 1.3 times. On the other hand, the lower limit of the draw ratio is preferably 1.05 times.

(Stretching)
The stretching method for stretching the PVA film is not particularly limited, and a wet stretching method or a dry stretching method can be adopted. However, the wet stretching method is preferable from the viewpoint of improving the thickness uniformity in the width direction of the obtained polarizing film.

  When the wet stretching method is employed, stretching may be performed in an aqueous solution containing a boron compound, or may be performed in an aqueous solution containing the dichroic dye or in a fixing treatment bath described later. Examples of the boron compound include boric acid salts such as boric acid and borax, and one or more of these can be used. Among these, it is preferable to perform stretching in an aqueous solution containing a boron compound, and it is more preferable to perform stretching in an aqueous solution containing boric acid. In this case, the upper limit of the concentration of boric acid in the aqueous solution containing boric acid is preferably 6% by mass, more preferably 5% by mass, and still more preferably 4% by mass. On the other hand, the lower limit of the boric acid concentration is preferably 0.5% by mass, more preferably 1% by mass, and even more preferably 1.5% by mass. The aqueous solution containing the boron compound may contain potassium iodide. In this case, the concentration of potassium iodide in the aqueous solution containing the boron compound is preferably 0.01% by mass or more and 10% by mass or less.

  When employing the dry stretching method, stretching may be performed at room temperature, stretching may be performed while heating, or stretching may be performed after the PVA film is absorbed.

  As an upper limit of the temperature at the time of extending | stretching a PVA film in the said extending | stretching, 90 degreeC is preferable, 80 degreeC is more preferable, and 70 degreeC is further more preferable. On the other hand, as a minimum of the above-mentioned temperature, 30 ° C is preferred, 40 ° C is more preferred, and 50 ° C is still more preferred.

  The lower limit of the stretching ratio of the PVA film in the stretching is preferably 1.2 times, more preferably 1.5 times, and even more preferably 2 times.

  In addition, the total draw ratio including the draw ratio of the above-mentioned pre-stretch (the ratio obtained by multiplying the stretch ratio of each stretch) is the original length of the PVA film before stretching from the viewpoint of the polarizing performance of the obtained polarizing film. Based on this, it is preferably 5.5 times or more, more preferably 5.7 times or more, further preferably 5.8 times or more, and particularly preferably 5.9 times or more. The upper limit of the total stretching ratio is not particularly limited, but 8 times is preferable.

  The stretching of the PVA film is preferably uniaxial stretching from the viewpoint of the performance of the obtained polarizing film. There is no restriction | limiting in particular in the direction of this uniaxial stretching, The uniaxial stretching and the horizontal uniaxial stretching to the length direction in a elongate PVA film are employable. Among these, uniaxial stretching in the length direction is preferable because a polarizing film that is superior in polarization performance is easily obtained. The uniaxial stretching in the length direction can be performed by, for example, using a stretching apparatus including a plurality of rolls parallel to each other and changing the peripheral speed between the rolls. On the other hand, the horizontal uniaxial stretching can be performed using a tenter type stretching machine.

(Fixed processing)
The fixing treatment can be performed by immersing the PVA film in a fixing treatment bath. Thereby, adsorption | suction of the dichroic dye to the said PVA film can be strengthened. The fixing process is not particularly limited as long as it is after dyeing, and the fixing process may be performed before stretching, the fixing process may be performed simultaneously with the stretching, or the fixing process may be performed after the stretching.

  Examples of the fixing treatment bath include an aqueous solution containing a boron compound. Examples of the boron compound include borates such as boric acid and borax. This boron compound may use only 1 type and may use 2 or more types together. The upper limit of the concentration of the boron compound in the aqueous solution containing the boron compound is preferably 15% by mass, and more preferably 10% by mass. On the other hand, the lower limit of the concentration of the boron compound is preferably 2% by mass, and more preferably 3% by mass.

  The upper limit of the temperature of the fixing treatment bath is preferably 60 ° C, and more preferably 40 ° C. On the other hand, the lower limit of the temperature of the fixing treatment bath is preferably 15 ° C and more preferably 25 ° C.

(Dry)
A polarizing film can be obtained by extending | stretching and performing a fixing process as needed, and drying. The drying conditions are not particularly limited, but the lower limit of the drying temperature is preferably 30 ° C and more preferably 50 ° C. On the other hand, as an upper limit of drying temperature, 150 degreeC is preferable and 130 degreeC is more preferable. By setting the drying temperature within the above range, the dimensional stability of the polarizing film is improved.

[Other PVA films]
In the present invention, the PVA film other than the above-described polarizing film and retardation film among the PVA films to be bonded to the base material by the adhesive, for example, an optical film other than the polarizing film and retardation film, a conductive film, a photosensitive film, Examples thereof include a protective film, a release film, a rust preventive film, a cover lay film, a transfer film, a polishing film, a window film, a decorative film, an adhesive film, a film for damping steel plate, a biodegradable film, and an antibacterial film. Examples of the optical film other than the polarizing film and the retardation film include, for example, an antireflection film, an alignment film, a polarizing layer protective film, a viewing angle improving film, a brightness improving film, an electromagnetic wave shielding film, a light shielding film, an infrared shielding film, an ultraviolet shielding film, Examples thereof include a lens filter, an optical low-pass filter (OLPF) film, and a weather-resistant film.

[Base material]
In the present invention, the base material to which the adhesive is bonded to the PVA film is not particularly limited, and examples thereof include films, various shapes such as hollow or solid block bodies, and the like is particularly preferable. Examples of the film include ionomer, polyethylene, cellulose, triacetyl cellulose (TAC), (meth) acrylic polymer, alicyclic structure-containing polymer, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polypropylene, polyester, Examples include films containing polymers such as polycarbonate, polystyrene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, and nylon. Here, in the (meth) acrylic polymer, a lactone ring unit, a maleic anhydride unit, an N-substituted or unsubstituted maleimide unit, a glutaric anhydride unit, an N-substituted or unsubstituted glutarimide unit, etc. are introduced into the main chain. It may be a modified (meth) acrylic polymer. Among these, a film containing triacetyl cellulose, a film containing a (meth) acrylic polymer, a polyester because it can function as a good protective film when a polarizing film or a retardation film is used as the PVA film. Or a film containing an alicyclic structure-containing polymer is preferred. The upper limit of the content of the polymer in the film is preferably 100% by mass. On the other hand, as a minimum of the above-mentioned content rate, 50 mass% is preferred, 80 mass% is more preferred, and 85 mass% is still more preferred.

  In the case where the substrate is a film, the thickness is not particularly limited, but the upper limit is preferably 200 μm, more preferably 80 μm. On the other hand, the lower limit of the thickness is preferably 5 μm, and more preferably 10 μm. When the said thickness is below the said upper limit, it can suppress that the thickness of the adhesive body obtained increases unnecessarily. On the other hand, when the thickness is equal to or more than the lower limit, the strength of the obtained bonded body is improved.

  Even when the substrate is not a film, a substrate containing the same polymer as that in the case where the substrate is a film can be preferably used. In this case, the upper limit of the content of the polymer in the substrate is preferably 100% by mass. On the other hand, as a minimum of the above-mentioned content rate, 50 mass% is preferred, 80 mass% is more preferred, and 85 mass% is still more preferred. The base material may include metal, fiber, fabric, synthetic leather, and the like.

[Use of adhesive]
The use of the adhesive of the present invention includes the use of bonding the polarizing film or retardation film and the protective film as described above (use for producing a polarizing plate or a retardation plate); metal in the production of electronic elements, electronic devices, and the like. Adhesion between synthetic resin, rubber, etc. and PVA film; Adhesion of materials in civil engineering and construction fields; Adhesion of fibers, fabrics, synthetic leather, etc. in clothing; Adhesion of food packaging, etc. Polarizing plate or retardation plate It is particularly useful in the production of the present invention, particularly in the production of polarizing plates.

  According to the adhesive of the present invention, the adhesive between the PVA film and the substrate has high adhesive strength. As specific adhesive strength, as the peel adhesive strength between the PVA film and the base material after curing of the adhesive, the lower limit is preferably 2.5N / 25mm, more preferably 3N / 25mm, and 3.75N. / 25 mm is more preferable.

<Adhesive>
Next, an embodiment of the adhesive body of the present invention will be described. The adhesive body 1 in FIG. 1 includes a PVA film 2, a base material 4, and an adhesive layer 3 disposed between the PVA film 2 and the base material 4. The adhesive layer 3 is formed from the adhesive.

[Adhesive layer]
The adhesive layer 3 is formed from the adhesive. Specifically, it can be formed by irradiating the adhesive with active energy rays. The adhesive layer 3 may contain an additive depending on the application of the adhesive body 1.

  The upper limit of the thickness of the adhesive layer 3 is preferably 500 μm, more preferably 50 μm, further preferably 20 μm, and particularly preferably 10 μm. On the other hand, the lower limit of the thickness is preferably 100 nm, more preferably 300 nm, and even more preferably 500 nm. When the thickness of the adhesive layer 3 is equal to or less than the upper limit, it is possible to suppress an unnecessary increase in the thickness of the obtained bonded body 1. On the other hand, when the thickness is equal to or greater than the lower limit, the adhesive strength between the PVA film 2 and the substrate 4 is improved.

<Manufacturing method of adhesive body>
The adhesive 1 is bonded to the active energy ray after the step of obtaining a laminate in which the PVA film 2, the adhesive, and the base material 4 are arranged in this order (laminate production step), and the laminate production step. It can manufacture with a manufacturing method provided with the process (irradiation process) irradiated to an agent.

[Laminate manufacturing process]
In the laminate manufacturing process, the laminate is manufactured. The method for producing the laminate is not particularly limited as long as a laminate in which the PVA film, the adhesive, and the base material are arranged in this order is obtained, but since the laminate can be obtained more easily, the adhesive. A method of superimposing the PVA film and the substrate after applying the adhesive to one or both of the surface of the PVA film and the surface of the substrate is preferable. The application method when applying the adhesive to one or both of the surface of the PVA film and the surface of the substrate is not particularly limited. For example, die coating, roll coating, air knife coating, gravure roll coating, doctor roll coating, Examples include doctor knife coating, curtain flow coating, spraying, wire bar, rod coating, dipping, and brush coating.

  Moreover, as a manufacturing method of the said laminated body, after superposing | stacking a PVA film and a base material other than the above, the method of making the said adhesive osmose | permeate between both can also be employ | adopted.

  Furthermore, you may pressurize the obtained laminated body with a roll. In this case, examples of the material of the roll include metal and rubber. The roll on the PVA film side and the roll on the substrate side may be the same material or different materials.

[Irradiation process]
In the irradiation step, active energy rays are irradiated to the uncured adhesive in the laminate. This active energy ray can be appropriately selected according to the type of the active energy ray-curable group contained in the adhesive. Examples of the active energy rays include electromagnetic waves such as ultraviolet rays, infrared rays, X rays, and γ rays, as well as electron rays, proton rays, and neutron rays. Among these, ultraviolet rays or electron beams are preferred from the viewpoints of curing speed, availability of irradiation equipment, price, etc., and ultraviolet rays are more preferred.

  The active energy ray can be irradiated using a known apparatus. When ultraviolet rays are used as the active energy ray, 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 that emits light in a wavelength region of 450 nm or less can be used. When an electron beam (EB) is used as the active energy ray, the acceleration voltage is preferably 0.1 MeV to 10 MeV, and the irradiation dose is preferably 1 kGy to 500 kGy.

The lower limit of the integrated light quantity of the active energy ray, preferably ^{10mJ / cm 2, 30mJ / cm} 2 is more preferable. On the other hand, the upper limit of the cumulative amount of the active energy ray, preferably 20,000mJ / cm ^2, and more preferably 5,000 mJ / cm ^2. When the integrated light amount of the active energy ray is equal to or more than the above lower limit, the curing rate of the adhesive and the adhesive strength after curing are improved. On the other hand, when the integrated light amount of the active energy ray is not more than the above upper limit, the irradiation time can be within an appropriate range, and the productivity is improved.

  Curing may be promoted by heating as necessary during or after irradiation of the active energy ray to the adhesive. As a minimum of this heating temperature, 40 degreeC is preferable and 50 degreeC is more preferable. On the other hand, as an upper limit of heating temperature, 130 degreeC is preferable and 100 degreeC is more preferable. When the heating temperature is at least the above lower limit, the effect of promoting curing is improved. On the other hand, when the heating temperature is not more than the above upper limit, deterioration of the adhesive is suppressed.

  By curing the adhesive, an adhesive layer is formed, and the adhesive body is obtained.

<Other embodiments>
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the above-described embodiment, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  The adhesive body may have a plurality of adhesive layers. For example, the PVA film further has an adhesive layer on the side opposite to the side where the adhesive layer is formed as described above, and another substrate is provided on the side of the adhesive layer opposite to the PVA film. It may have a structure of base material / adhesive layer / PVA film / adhesive layer / base material by being laminated, or PVA film / adhesive layer / base material / adhesive layer / PVA. It may have a film structure.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

<Preparation of adhesive>
[Synthesis of (meth) acrylic polymer (P-1)]
100 ml of toluene was put into a 300 ml flask which had been dried and purged with nitrogen, and 0.78 ml (2.86 mmol) of 1,1,4,7,10,10-hexamethyltriethylenetetramine as a Lewis base while stirring. Then, 12.7 ml of a 0.450 mol / L toluene solution of isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum as a tertiary organoaluminum compound was sequentially added. This solution is cooled to -20 ° C, and 1.30 mol / L cyclohexane solution of sec-butyllithium as an organolithium compound is added to 2.00 ml, and 1,1-dimethylpropane as an active energy ray curable monomer is added. 3.58 ml of a mixture of 2.47 ml (10.4 mmol) of 1,3-diol dimethacrylate and 1.11 ml (10.4 mmol) of methyl methacrylate as a mono (meth) acrylate was added all at once, Polymerization was started (first polymerization step). Ten minutes after the start of anionic polymerization, the polymerization reaction solution changed from the original yellow color to colorless. The polymerization reaction liquid was further stirred for 10 minutes.
Next, while stirring this polymerization reaction solution at −20 ° C., 2.22 ml (20.8 mmol) of methyl methacrylate as a monomethacrylic acid ester was added all at once. After 100 minutes, acrylic acid as a monoacrylic acid ester was added. Anionic polymerization was carried out by further adding 37.4 ml (260 mmol) of n-butyl at a rate of 1 ml / min (second polymerization step).
Thereafter, 10.0 ml of methanol was added at −20 ° C. while stirring the polymerization reaction solution to stop anionic polymerization. The obtained solution was poured into 1 liter of methanol, and the precipitate was collected to obtain a (meth) acrylic polymer (P-1). Mn of the (meth) acrylic polymer (P-1) was 24,700, and Mw / Mn was 1.21.

  Among the compounds used for the preparation of the adhesive, those other than the (meth) acrylic polymer (P-1) are shown below.

[Compound (Y)]
M-1: Tetrahydrofurfuryl acrylate (“Biscoat 150” manufactured by Osaka Organic Chemical Co., Ltd.)
M-2: 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (“Celoxide 2021P” manufactured by Daicel Chemical Industries, Ltd.)
M-3: 3-ethyl-3-hydroxymethyloxetane (“OXT-101” manufactured by Toagosei Co., Ltd.)
M-4: 3-ethyl-3-acryloyloxymethyl oxetane (“OXE-10” manufactured by Osaka Organic Chemical Co., Ltd.)
L-1: Tris (2-hydroxyethyl) isocyanurate triacrylate (“M-315” manufactured by Toa Gosei Co., Ltd.)

[Active energy ray polymerization initiator (P)]
Radical polymerization initiator (R-1): 1-hydroxycyclohexyl phenyl ketone ("IRGACURE 184" manufactured by BASF)
Cationic polymerization initiator (C-1): Diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate in 50% by mass solution of propylene carbonate (“CPI-100P” manufactured by San Apro)

[Example 1]
<Manufacture of adhesives>
In a container with a stirrer capable of being sealed, 14 parts by mass of the (meth) acrylic polymer (P-1), 43 parts by mass of (M-1) as the compound (Y), 33 parts by mass of (M-2) and (L-1) 5 parts by mass, 3 parts by mass of (R-1) as radical polymerization initiator (R) and 2 parts by mass of (C-1) as cationic polymerization initiator (C) were charged for 24 hours. The adhesive (A-1) was prepared by stirring.

<Manufacture of adhesive body (polarizing plate)>
Using a polymethyl methacrylate film (made by Kuraray Co., Ltd.) having a thickness of 50 μm as a base material, the adhesive (A-1) is 2 μm in thickness using a bar coater on one surface of the polymethyl methacrylate film. Coated so that. Next, a polarizing film having a thickness of 10 μm (manufactured by dyeing and stretching the PVA film with an iodine-based dye) was superposed on the substrate via this adhesive. Thereafter, the adhesive (A-1) is applied to the surface of the polarizing film that is not in contact with the adhesive using a bar coater so that the thickness is 2 μm, and the thickness is 50 μm as another substrate. A polymethyl methacrylate film (manufactured by Kuraray Co., Ltd.) was superposed on the polarizing film via the adhesive. The laminate having the layer structure of polymethyl methacrylate film / adhesive / polarizing film / adhesive / polymethyl methacrylate film thus obtained was pressed using a roller.
Thereafter, using an ultraviolet irradiation device (using a metal halide lamp manufactured by GS YUASA Co., Ltd. as a lamp), the laminate was irradiated with ultraviolet rays so that the integrated light amount became 700 mJ / cm ² . In addition, about this integrated light quantity, it measured using the UV measuring device (GS YUSASA Corporation). After irradiating with ultraviolet rays, a polarizing plate as an adhesive was obtained by allowing to stand at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours. As for the size of the polarizing plate and the laminate, the width 10 mm × length 50 mm is used for evaluating the curing speed and peel adhesive strength, and the width 50 mm × length 50 mm is used for evaluating the amount of warpage. It was.

<Evaluation>
About said polarizing plate, each evaluation was performed with the following procedures. In addition, about evaluation of a curing rate, the laminated body immediately after ultraviolet irradiation in manufacture of the said adhesive body (polarizing plate) was used.

[Crosslinking density after curing and storage modulus at 150 ° C.]
An adhesive is applied onto the release-treated base film, and this is irradiated with ultraviolet rays using an ultraviolet irradiation device (using a metal halide lamp manufactured by GS YUASA Co., Ltd. as a lamp) so that the integrated light quantity becomes 700 mJ / cm ^2. did. In addition, about this integrated light quantity, it measured using the UV measuring device (GS YUSASA Corporation). After the ultraviolet irradiation, the cured product was peeled off from the base film after standing at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours. Thus, the dynamic viscoelasticity measurement was performed with respect to the sample of the hardened | cured material obtained using the dynamic viscoelasticity measuring apparatus ("Rheogel-E4000" by UBM Co., Ltd.). Then, the storage elastic modulus (E ′) is obtained at a temperature of 150 ° C. belonging to the rubber-like flat region, and the crosslinking density is determined from the relationship of E ′ = 3νRT using the value of the storage elastic modulus (E ′) at 150 ° C. Asked. In all Examples and Comparative Examples, the Tg of the cured product was sufficiently smaller than 120 ° C.

[Curing speed]
About the laminated body immediately after ultraviolet irradiation, after cutting the adhesive layer part with the cutter as needed, the polarizing film and one polymethyl methacrylate film were peeled by hand. Because the curing of the adhesive is sufficient, the polarizing film and the polymethyl methacrylate film cannot be completely peeled off, and the damaged polymethyl methacrylate film is A (good), and the curing of the adhesive is insufficient. The polarizing film and the polymethyl methacrylate film could be easily peeled off, and none of the films was damaged was evaluated as B (defective).

[Peeling adhesive strength]
The polarizing plate was allowed to stand still for 24 hours at a temperature of 23 ° C. and a relative humidity of 50%, and then a polarizing film and a polarizing film at a peeling rate of 30 mm / min in accordance with JIS-K6854-2 (1999) using a small tensile tester. The peel force when the polymethyl methacrylate film was peeled 180 ° was measured. The obtained measured value was multiplied by 2.5 to obtain a converted value in the case of a width of 25 mm.

[Warpage amount]
The polarizing plate was allowed to stand for 24 hours at a temperature of 23 ° C. and a relative humidity of 60%, and then placed on a smooth surface, and the distance between the smooth surface and the corner of the polarizing plate was measured for each of the four corners. A large value was defined as a warpage amount (limit warpage amount). The amount of warpage (limit warpage amount) is preferably 1 mm or less. These results are shown in Table 2.

[Examples 2 to 6 and Comparative Examples 1 to 4]
Adhesives (A-2) to (A-6) and (CA-1) to (CA-4) were used in the same manner as in Example 1 except that the types and amounts used of the compounds shown in Table 1 were used. ) Was prepared. In adhesive (A-6), it replaced with the (meth) acrylic-type polymer (P-1), and acrylic resin acrylate ("KRAD-3611" by Negami Kogyo Co., Ltd.) (P-2) was used. In the adhesives (CA-1) and (CA-2), a polyether urethane acrylate (“Iupimer AU-2300” manufactured by Mitsubishi Chemical Corporation) is used instead of the (meth) acrylic polymer (P-1). (P-3) was used. In Table 1, “-” indicates that the compound is not used.

  Moreover, it carried out similarly to Example 1 except having used adhesive agent (A-2)-(A-6) and (CA-1)-(CA-4), respectively instead of adhesive agent (A-1). Thus, an adhesive body (polarizing plate) was produced, and each evaluation similar to Example 1 was performed. These results are shown in Table 2.

  As shown in Table 2, the adhesives of the examples all show high peel adhesion strength, high adhesion strength in the adhesion between the PVA film and the substrate, high curing speed, and warping of the polarizing plate. Can be reduced. On the other hand, the adhesive of the comparative example was inferior in peel adhesion strength, and the curing rate was slow or the amount of warping of the polarizing plate was large.

DESCRIPTION OF SYMBOLS 1 Adhesive body 2 PVA film 3 Adhesive layer 4 Base material

Claims (14)

An adhesive for bonding a film containing polyvinyl alcohol and a substrate,
(Meth) acrylic polymer (X) having an active energy ray-curable group;
Containing a compound (Y) having an active energy ray-curable group other than the (meth) acrylic polymer (X) ,
The active energy ray-curable group possessed by the (meth) acrylic polymer (X) is a group having a group represented by the following formula (1),
The (meth) acrylic polymer (X) has a (meth) acrylic polymer block (A) having an active energy ray-curable group and substantially no active energy ray-curable group (meth). An acrylic polymer block (B),
An adhesive in which the compound (Y) is a compound having a group represented by the following formula (3) (provided that (a) at least two alicyclic epoxy groups represented by the following formula (i) are present in the molecule. An epoxy compound having (b) a poly (meth) acrylate of a polyol having 2 to 15 carbon atoms, (c) a photocationic polymerization initiator, (d) an oxetane compound represented by the following formula (ii), and (e) an alkyl It contains a polymer having (meth) acrylate as an essential constituent monomer unit, and the content ratio of the components (a) to (e) is (a) component: 10 to 65% by weight (b) component: 10 to 10%. 55% by weight (c) component: 0.5 to 10% by weight (d) component: 1 to 25% by weight (e) component: excluding those having 0.1 to 25% by weight) .

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

(In the formula, R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, X ² represents an oxygen atom, a sulfur atom or —NR ⁶ —, and R ⁶ represents a hydrogen atom or a carbon atom having 1 to 6 carbon atoms. Represents a hydrocarbon group.)

The adhesive according to claim 1, wherein the active energy ray-curable group of the (meth) acrylic polymer (X) is a group represented by the following formula (2).

(In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, R ² and R ³ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and X ¹ represents oxygen atom, a sulfur atom or -NR ⁴ - represents, ^{R 4} represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, n represents an integer of 1 to 20). The adhesive according to claim 1 or 2 , wherein the content of the (meth) acrylic polymer (X) is 1% by mass or more and 90% by mass or less. The content rate of the said compound (Y) is 10 mass% or more and 99 mass% or less, The adhesive agent of any one of Claims 1-3 . The adhesive according to any one of claims 1 to 4 , further comprising an active energy ray polymerization initiator (P). Crosslink density determined from a storage elastic modulus of the rubbery plateau region obtained by dynamic viscoelasticity measurement after hardening is not more than 0.4 mol / L or more 2 mol / L any one of claims 1 to 5 The adhesive described in 1 . The adhesive according to claim 6 , wherein a storage elastic modulus at 150 ° C. obtained by measuring dynamic viscoelasticity after curing is 4 × 10 ⁶ Pa or more and 21 × 10 ⁶ Pa or less. The adhesive according to any one of claims 1 to 7 , wherein the film containing polyvinyl alcohol is a stretched polyvinyl alcohol film. The adhesive according to claim 8 , wherein the stretched polyvinyl alcohol film is a polarizing film or a retardation film. The adhesive according to any one of claims 1 to 9 , wherein the substrate is a film. The adhesive according to claim 10 , wherein the film contains triacetyl cellulose, a (meth) acrylic polymer, a polyester, or an alicyclic structure-containing polymer. The adhesive according to any one of claims 1 to 11 , wherein a peel adhesive strength between the film containing polyvinyl alcohol and the substrate after curing is 2.5 N / 25 mm or more. An adhesive comprising a film containing polyvinyl alcohol, a substrate, a film containing polyvinyl alcohol and an adhesive layer disposed between the substrate,
Adhesive material the adhesive layer is formed from the adhesive according to any one of claims 1 to 12. Film comprising a polyvinyl alcohol, an adhesive as claimed in any one of claims 12, and to obtain a laminate base material are arranged in this order, and after the step of obtaining the laminate, active energy The manufacturing method of an adhesive body provided with the process of irradiating a line | wire to the said adhesive agent.

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