JP2009155523A - Resin composition and adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which is used for an adhesive capable of bonding materials to be bonded having mutually different polarities, such as a polar material and a nonpolar material, to each other with a high adhesive strength. <P>SOLUTION: The resin composition includes: (A) component: a (meth)acrylic acid ester copolymer obtained by polymerizing a monomer component containing a (meth)acrylic acid ester monomer (A-1) having an alicyclic structure and a monomer (A-2) capable of copolymerizing with the monomer (A-1); and (B) component: a polyvinyl alcohol resin. The (A) component is obtained by polymerizing a monomer component comprising 0.1-99 parts by mass of the monomer (A-1) and 1 to 99.9 parts by mass of the monomer (A-2), wherein the total amount of the monomer (A-1) and the monomer (A-2) is 100 parts by mass. The resin composition includes 0.1 to 100 parts by mass of the (B) component based on 100 parts by mass of the (A) component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin composition and an adhesive. More specifically, a resin composition used for an adhesive capable of bonding adherends having different polarities such as a polar material and a nonpolar material with high adhesive force, and such a resin composition The present invention relates to an adhesive containing

  In recent years, research and development for applying liquid crystal materials to optical applications has been actively conducted. An alignment film obtained by aligning the liquid crystal material into a film has been put to practical use for liquid crystal display color compensation or viewing angle expansion.

  Such an oriented film is used in a state of a laminated structure in which a retardation film or the like is combined with a polarizing plate via an adhesive or the like.

  In the case where the above polarizing plate is made of a hygroscopic polyvinyl alcohol resin, its characteristics change depending on the external environment. Therefore, this polarizing plate is used as a protective film (for example, a triacetyl cellulose film. It is necessary to protect it with a film.

  Examples of the adhesive for adhering such a polarizing plate or TAC film and the retardation film include a monomer having an ethylenically unsaturated double bond and a polymerizable carbonyl group in the molecule, An adhesive containing a polymer emulsion formed by emulsion polymerization using a monomer having a heavy bond and a benzene ring in the molecule and a monomer having an ethylenically unsaturated double bond and a carboxyl group is used (for example, Patent Documents 1 to 3).

JP 2006-52359 A JP 2006-168243 A JP-A-8-165464

  However, the above polarizing plate and TAC film are made of a polar material such as polyvinyl alcohol resin or triacetyl cellulose, whereas the above retardation film is usually a nonpolar material such as a norbornene resin. Therefore, even if both are bonded using a conventional adhesive, a sufficient adhesive force cannot be obtained, for example, peeling occurs at the interface between the polarizing plate and the retardation film. was there.

  In addition, after the alignment film is disposed on the glass cell, the alignment film and the glass are removed when a defective portion of the alignment film is removed and the alignment film is reattached (hereinafter sometimes referred to as “rework”). Since the adhesive strength of the adhesive that adheres to the cell is higher than the adhesive strength in the laminated structure of the oriented film (for example, the adhesive strength to adhere the polarizing plate and the retardation film), the oriented film was removed. There was also a problem that a retardation film or the like remained on the glass cell.

  For this reason, for example, adhesion capable of adhering adherends having different polarities to each other with high adhesive force, such as a polar material such as polyvinyl alcohol resin and a nonpolar material such as norbornene resin. Development of a resin composition used for the agent is eagerly desired.

  The present invention has been made in view of such problems of the prior art, and adherends having different polarities, such as a polar material and a nonpolar material, can be bonded with high adhesive force. Provided are a resin composition suitably used for a possible adhesive and an adhesive containing such a resin composition.

  As a result of intensive studies to solve the problems of the prior art as described above, the present inventors have found that a polyvinyl alcohol resin capable of exhibiting a good adhesive force to a polar material and a good adhesion to a nonpolar material. The present inventors have found that the above-mentioned problems can be solved by a resin composition containing a specific (meth) acrylic acid ester copolymer capable of developing force, and have completed the present invention. It was. Specifically, the following resin composition and adhesive are provided by the present invention.

[1] (A) A monomer component containing a (meth) acrylic acid ester monomer (A-1) having an alicyclic structure and a monomer (A-2) copolymerizable with the monomer (A-1) is polymerized. (Meth) acrylic acid ester copolymer and (B) polyvinyl alcohol resin obtained, and the (A) (meth) acrylic acid ester copolymer is the monomer (A-1) 0. The monomer component comprising 1 to 99 parts by mass and 1 to 99.9 parts by mass of the monomer (A-2) (provided that the monomer (A-1) + monomer (A-2) = 100 parts by mass) A resin containing 0.1 to 100 parts by mass of the (B) polyvinyl alcohol resin with respect to 100 parts by mass of the (A) (meth) acrylic acid ester copolymer. Composition.

[2] The resin composition according to [1], which is a mixture containing the (A) (meth) acrylic acid ester copolymer and the (B) polyvinyl alcohol resin.

[3] The resin composition according to [1], which is a graft copolymer obtained by graft polymerization of the (A) (meth) acrylic acid ester copolymer and the (B) polyvinyl alcohol resin.

[4] The resin composition according to any one of [1] to [3], further comprising (C) a water-soluble epoxy compound.

[5] The resin composition according to any one of [1] to [4], wherein the saponification degree of the (B) polyvinyl alcohol resin is 50 to 100 mol%.

[6] An adhesive containing the resin composition according to any one of [1] to [5].

  The resin composition of the present invention can be suitably used as an adhesive that adheres adherends having polarities different from each other, such as a polar material and a nonpolar material, with high adhesive force. For example, such an adhesive can favorably bond a polarizing plate made of a polar material and a retardation film made of a nonpolar material. Moreover, the adhesive of this invention can adhere | attach the adherends which have the different polarity mentioned above with high adhesive force.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

[1] Resin composition:
The resin composition of the present invention comprises (A) a (meth) acrylic acid ester monomer (A-1) having an alicyclic structure and a monomer (A-2) copolymerizable with the monomer (A-1). It contains (meth) acrylic acid ester copolymer obtained by polymerizing the monomer component and (B) polyvinyl alcohol resin.

  In this resin composition, a polar material (B) polyvinyl alcohol resin (hereinafter sometimes referred to as “component (B)”) can exhibit a good adhesive force, and a non-polar material. On the other hand, the (A) (meth) acrylic acid ester copolymer (hereinafter sometimes referred to as “component (A)”) can exhibit good adhesive strength.

  Thus, since the resin composition contains adhesive components for each of a polar material and a nonpolar material, for example, adherends having different polarities, such as a polar material and a nonpolar material, are attached to each other. It can be suitably used for an adhesive that adheres with high adhesive strength. In addition, this resin composition is a film laminate having a layer (intermediate layer) made of this resin composition by coating and arranging between two or more films made of a polar material or a nonpolar material. It can be suitably used also when forming.

  The (A) (meth) acrylic acid ester copolymer is composed of 0.1 to 99 parts by mass of a (meth) acrylic acid ester monomer (A-1) having an alicyclic structure and a monomer (A-2) 1 It is obtained by polymerizing a monomer component containing ˜99.9 parts by mass (however, monomer (A-1) + monomer (A-2) = 100 parts by mass).

  By comprising in this way, the structural unit derived from the (meth) acrylic acid ester monomer (A-1) which has an alicyclic structure functions well as an adhesive component with respect to a nonpolar material.

  Moreover, in this resin composition, 0.1-100 mass parts of (B) polyvinyl alcohol resin contains with respect to 100 mass parts of said (A) (meth) acrylic acid ester copolymers. By comprising in this way, the favorable adhesion | attachment of the to-be-adhered bodies which have a different polarity is implement | achieved.

  The resin composition of the present invention may be a mixture containing (A) (meth) acrylic acid ester copolymer and (B) polyvinyl alcohol resin, or (A) (meth) acrylic acid ester copolymer. It may contain a graft copolymer obtained by graft polymerization of a polymer and (B) a polyvinyl alcohol resin.

  For example, when the resin composition is a mixture of the component (A) and the component (B), an adhesive having a high adhesive force can be easily produced. On the other hand, when the resin composition contains a graft copolymer of the component (A) and the component (B), it is possible to further improve the adhesive force to adherends having different polarities. It becomes.

  Hereinafter, each component of the resin composition of the present invention will be described in more detail.

[1-1] (A) (Meth) acrylic acid ester copolymer:
(A) (meth) acrylic acid ester copolymer is copolymerized with 0.1 to 99 parts by mass of (meth) acrylic acid ester monomer (A-1) having an alicyclic structure and this monomer (A-1). Copolymers obtained by polymerizing monomer components including 1 to 99.9 parts by mass of the possible monomer (A-2) (provided that the monomer (A-1) + the monomer (A-2) = 100 parts by mass). It is a polymer.

  As described above, since the (A) (meth) acrylic acid ester copolymer includes a structural unit derived from the monomer (A-1) having an alicyclic structure, for example, a norbornene resin is used. A high adhesion force to an adherend made of a nonpolar material can be expressed.

  As described above, the content ratio of the monomer (A-1) to the monomer (A-2) in the monomer component is 0.1 to 99 parts by mass of the monomer (A-1). 2) is 1 to 99.9 parts by mass, but in the resin composition of the present invention, the monomer (A-2) is 5 to 70 parts by mass with respect to 30 to 95 parts by mass of the monomer (A-1). The monomer (A-2) is more preferably 10 to 60 parts by mass, and the monomer (A-1) 50 to 85 parts by mass with respect to 40 to 90 parts by mass of the monomer (A-1). It is particularly preferable that the monomer (A-2) is 15 to 50 parts by mass with respect to parts. However, in the said content rate, it is a monomer (A-1) + monomer (A-2) = 100 mass parts.

  By comprising in this way, the structural unit derived from the (meth) acrylic acid ester monomer (A-1) which has an alicyclic structure functions well as an adhesive component with respect to a nonpolar material. If the monomer (A-1) is less than 30 parts by mass, adhesion to non-polar materials may not be exhibited. On the other hand, if it exceeds 95 parts by mass, film formation failure may occur when used as an adhesive. This may occur and a preferable adhesive force may not be obtained.

[1-1a] Monomer (A-1):
The monomer (A-1) is a (meth) acrylic acid ester having an alicyclic structure, and specifically, an ester of (meth) acrylic acid and an alcohol having an alicyclic structure.

  Specific monomers (A-1) include, for example, cyclohexyl (meth) acrylate, isobornyl acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyl (meth) acrylate. Preferred examples include cycloalkyl (meth) acrylates such as dicyclopentadienyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanyl (meth) acrylate. In the resin composition of the present invention, cyclohexyl methacrylate is particularly preferable.

[1-1b] Monomer (A-2):
The monomer (A-2) is not particularly limited as long as it is a monomer copolymerizable with the monomer (A-1).

  Specific monomers (A-2) include (meth) acrylic acid, itaconic acid, fumaric acid, 2-ethylhexyl (meth) acrylate, butyl (meth) acrylate, ethyl (meth) acrylate, glycidyl (meth) acrylate, Examples include 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide, styrene, α-methylstyrene, and the like.

[1-1c] Method for producing (A) (meth) acrylic acid ester copolymer:
The method for producing the (A) (meth) acrylic acid ester copolymer is not particularly limited, and for example, an emulsion polymerization method, a suspension polymerization method, or a solution polymerization method can be used. Among these, it is preferable to manufacture by an emulsion polymerization method.

  When manufacturing by emulsion polymerization, first, for example, a monomer component containing each monomer (monomer (A-1) and monomer (A-2)) in water is emulsified using a surfactant. Thereafter, a radical polymerization initiator such as a peroxide catalyst or a redox catalyst as a polymerization initiator, and a molecular weight regulator such as a mercaptan compound or a terpene compound as necessary are added, for example, polymerization at 50 to 90 ° C. To do. In this way, an aqueous emulsion containing the (A) (meth) acrylic acid ester copolymer can be obtained.

  The component (A) used in the resin composition of the present invention may be used in the state of the aqueous emulsion thus obtained, or may be used after being isolated from the aqueous emulsion. In addition, by using (A) component in the state of the said aqueous emulsion, an aqueous adhesive can be manufactured using the resin composition containing this aqueous emulsion.

  Component (A) used in this resin composition preferably has a glass transition temperature (Tg) of -50 to 80 ° C, more preferably -20 to 50 ° C, and 0 to 40 ° C. Is particularly preferred.

  For example, when the glass transition temperature (Tg) of the component (A) is less than −50 ° C., the resin composition may cause cohesive failure when used as an adhesive, and a preferable adhesive force may not be obtained. When it exceeds 80 ° C., when it is used as an adhesive, a film formation failure may occur, and a preferable adhesive force may not be obtained.

  In this specification, “glass transition temperature (Tg)” refers to a value measured by a differential scanning calorimeter. Specifically, after the copolymer (for example, the component (A)) is dried by heating, a temperature rising rate of 10 ° C./min is measured using a differential scanning calorimeter (trade name “EXSTAR6000DSC” manufactured by Seiko Instruments Inc.). This is the value when analyzed under the conditions of

[1-2] (B) Polyvinyl alcohol resin:
(B) A polyvinyl alcohol resin becomes an adhesive component which expresses the adhesive force with respect to the adherend which consists of polar materials, such as a polarizing plate used as a liquid-crystal material, and a TAC film, for example.

  As such (B) polyvinyl alcohol resin, for example, polyvinyl alcohol obtained by saponifying polyvinyl acetate obtained by polymerizing general vinyl acetate, cross-linking reactive polyvinyl alcohol, polyvinyl alcohol having active terminal groups, and the like Can be mentioned. (A) From the viewpoint of developing adhesive force due to chemical bonding with the (meth) acrylic acid ester copolymer, the above-described cross-linking reactive polyvinyl alcohol and polyvinyl alcohol having an active terminal group are preferable.

  Moreover, as this (B) polyvinyl alcohol resin, it is preferable that the saponification degree is 50-100 mol%, It is more preferable that it is 70-100 mol%, It is 80-100 mol%. Particularly preferred. By comprising in this way, when a resin composition is used for an adhesive agent, high adhesive force can be expressed. For example, if the degree of saponification is less than 50 mol%, sufficient adhesive strength may not be obtained.

  Moreover, it is preferable that (B) polyvinyl alcohol resin has a carboxyl group in the structural unit. By comprising in this way, the adhesiveness to the to-be-adhered body which consists of polar materials can be improved, and high adhesive force can be expressed.

[1-3] (C) Water-soluble epoxy compound:
The resin composition of the present invention comprises (C) a water-soluble epoxy compound (hereinafter sometimes referred to as “(C) component”) in addition to the component (A) and the component (B) described above. Furthermore, you may contain.

  By further containing such a water-soluble epoxy compound (C), when the resin composition of the present invention is used as an adhesive, the adhesive strength of the adhesive can be further improved.

  (C) As a water-soluble epoxy compound, the water-soluble epoxy compound used for the conventional adhesive agent can be used, for example. In the present invention, polyethylene glycol diglycidyl ether, diglycerol polyglycidyl ether, glycerin diglycidyl ether and the like can be mentioned as preferred examples.

[2] Manufacturing method of resin composition:
Next, the manufacturing method of the resin composition of this invention is demonstrated.

  When manufacturing the resin composition of this invention, first, a monomer (A-1) and a monomer (A-2) are mixed and the monomer component for obtaining (A) component is prepared. The monomer component thus obtained is polymerized using, for example, the above-described emulsion polymerization method to produce an aqueous emulsion containing a (meth) acrylate copolymer (component (A)). As the polymerization method, a suspension polymerization method or a solution polymerization method can also be used.

  When the resin composition is a mixture of the component (A) and the component (B), the aqueous emulsion containing the component (A) described above is added to the polyvinyl alcohol resin as the component (B), and if necessary. The component (C) can be added and mixed.

  On the other hand, when the resin composition contains a graft copolymer obtained by graft polymerization of the component (A) and the component (B), it can be produced, for example, as follows.

  First, the monomer component which mixed the monomer (A-1) and the monomer (A-2) is prepared.

  Next, the aqueous solution containing the component (B) is put into an autoclave or the like, and as a polymerization initiator, a radical polymerization initiator such as a peroxide catalyst or a redox catalyst, and a molecular weight regulator such as a mercaptan compound or a terpene compound as necessary. For example, and heated to 50-90 ° C.

  Next, the monomer component described above was continuously supplied into the autoclave over a certain period of time to polymerize the monomer (A-1) and the monomer (A-2), and thus obtained (A ) Component and (B) component are graft-polymerized. Thus, the resin composition containing the graft copolymer of (A) component and (B) component can be manufactured.

[3] Adhesive:
Next, an embodiment of the adhesive of the present invention will be described. The adhesive of the present invention is an adhesive containing the resin composition of the present invention described so far.

  As described above, the adhesive of the present invention can express a component (B) that can express a good adhesive force to a polar material and a good adhesive force to a non-polar material ( A) The resin composition containing a component is contained. For this reason, for example, adherends having different polarities such as a polar material such as polyvinyl alcohol resin and a nonpolar material such as norbornene resin can be bonded with high adhesive force.

  The adhesive of the present invention is preferably an aqueous adhesive containing an aqueous emulsion containing a resin composition. Such a water-based adhesive can realize a strong adhesive force that was not found in conventional water-based adhesives. Moreover, since workability | operativity is good and it is a low odor, a working environment can be made favorable.

  The adhesive may further contain various additives used for conventional adhesives depending on the intended use. In addition, when using an adhesive agent for optical uses etc., it is preferable to set it as the adhesive agent which consists of the resin composition of this invention demonstrated until now, without adding an unnecessary additive.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the average particle diameter of the polymer which comprises an adhesive agent, and the measuring method of the adhesive force of the adhesive agent of this invention are shown below.

  [Average particle size]: Measured using a dense particle size analyzer “FPAR-1000” manufactured by Otsuka Electronics Co., Ltd.

  [Adhesive strength]: Using the adhesives obtained in the examples and comparative examples, a film laminate in which a film made of a polar material and a film made of a nonpolar material are bonded is obtained, and the obtained film laminate is obtained. The adhesive strength of each adhesive was measured using a 90 degree peel test with a peel rate of 5 mm / min using “Autograph AG-B500” manufactured by Shimadzu Corporation.

Example 1
[Preparation of monomer component (1)]
Mixing 69 parts by mass of cyclohexyl methacrylate as the monomer (A-1) and 25 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, and 3 parts by mass of methacrylic acid as the monomer (A-2), A monomer component (1) (mixture of monomers) for preparing the component (A) was prepared.

[Preparation of Component (A) (Aqueous Emulsion Containing Component (A))]
In an autoclave equipped with a stirrer, a temperature controller, and a reflux condenser, 420 parts by mass of water, 2 parts by mass of trade name “KH1025” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. as an emulsifier, and potassium persulfate 0 as a polymerization initiator 3 parts by mass, and the temperature was raised to 75 ° C.

  In this autoclave, the monomer component (1) was polymerized at 75 ° C. while continuously supplying 247 parts by mass of the total amount of the pre-emulsion prepared by the following method into the autoclave over 3 hours. By stirring at 80 ° C. for 3 hours to complete the polymerization reaction, an aqueous emulsion containing the component (A) was obtained.

  The pre-emulsion is emulsified by adding 100 parts by mass of the monomer component (1), 1 part by mass of a trade name “KH1025” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and 146 parts by mass of water as an emulsifier. It adjusted by doing.

  The resulting aqueous emulsion had a solid content concentration of 15.1%, and the average particle size of the polymer particles comprising the component (A) was 65 nm. Table 1 shows the formulation of the component (A).

[Manufacture of adhesives]
After the aqueous emulsion containing the component (A) thus obtained was adjusted to pH 7.5 with ammonia, a polyvinyl alcohol resin (trade name “GOHSENOL GL-03”, manufactured by Nippon Synthetic Chemical Co., Ltd.) was used as the component (B). ) Was added in an amount of 200 parts by mass (30 parts by mass as component (B)) to produce an adhesive composed of a resin composition.

[Production of film laminate]
As an adherend for measuring the adhesive strength of the adhesive of Example 1, a norbornene-based resin film (nonpolar material) having a thickness of 100 μm and a polyvinyl alcohol resin film (polar material) having a thickness of 100 μm were prepared. The two films were bonded with the adhesive of Example 1.

  When adhering, first, the surface of each film is corona-treated, and the adhesive of Example 1 is dropped on the treated surface of the norbornene-based resin film, and the treated surface of the polyvinyl alcohol resin film is immediately superimposed and applied with a nip roll. Pressure (nip temperature 23 ° C., nip pressure 100 N / cm) was stored in a constant temperature bath at 50 ° C. for 2 days to produce a film laminate.

  The adhesive strength of the adhesive was measured on the obtained film laminate according to the method described above. The measurement results are shown in Table 1.

(Example 2)
[Preparation of monomer component (2)]
In order to prepare component (A) by mixing 94 parts by mass of cyclohexyl acrylate as monomer (A-1) and 3 parts by mass of 2-hydroxyethyl methacrylate and 3 parts by mass of methacrylic acid as monomer (A-2). A monomer component (2) was prepared.

[Preparation of Component (A) (Aqueous Emulsion Containing Component (A))]
Except for using the monomer component (2), the monomer component (2) was polymerized in the same manner as in Example 1 to obtain an aqueous emulsion containing the component (A). The solid content concentration of the aqueous emulsion was 15.0%, and the average particle size of the polymer particles of the component (A) was 70 nm. Table 1 shows the formulation of the component (A).

[Manufacture of adhesive and production of film laminate]
An adhesive was produced in the same manner as in Example 1 except that the aqueous emulsion containing the component (A) obtained by the above method was used. Furthermore, using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

(Example 3)
[Preparation of monomer component (3)]
Mixing 62 parts by mass of isobornyl acrylate as the monomer (A-1) and 32 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, and 3 parts by mass of methacrylic acid as the monomer (A-2). Thus, a monomer component (3) for preparing the component (A) was prepared.

[Preparation of Component (A) (Aqueous Emulsion Containing Component (A))]
Except for using the monomer component (3), the monomer component (3) was polymerized in the same manner as in Example 1 to obtain an aqueous emulsion containing the component (A). The solid content concentration of this aqueous emulsion was 15.0%, and the average particle size of the polymer particles of component (A) was 76 nm. Table 1 shows the formulation of the component (A).

[Manufacture of adhesive and production of film laminate]
An adhesive was produced in the same manner as in Example 1 except that the aqueous emulsion containing the component (A) obtained by the above method was used. Furthermore, using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

Example 4
[Preparation of monomer component (4)]
Mixing 69 parts by mass of cyclohexyl methacrylate as the monomer (A-1) and 25 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, and 3 parts by mass of methacrylic acid as the monomer (A-2), A monomer component (4) for preparing the component (A) was prepared.

[Manufacture of adhesives]
In an autoclave equipped with a stirrer, a temperature controller, and a reflux condenser, 467 parts by mass of water, 10% of polyvinyl alcohol resin (trade name “GOHSENOL GL-03”, manufactured by Nippon Synthetic Chemical Co., Ltd.) as component (B) The aqueous solution was charged with 300 parts by mass (30 parts by mass as component (B)) and 0.3 part by mass of potassium persulfate as a polymerization initiator, and the temperature was raised to 75 ° C.

  While continuously supplying 100 parts by mass of the monomer component (4) to the autoclave over 3 hours, the monomer component is polymerized at 75 ° C., and further stirred at 80 ° C. for 3 hours. By completing the polymerization reaction, an aqueous emulsion containing a graft copolymer obtained by graft polymerization of the component (A) and the component (B) was obtained. The solid content concentration of this aqueous emulsion was 15.0%, and the average particle size of the polymer particles was 80 nm.

  The aqueous emulsion thus obtained was adjusted to pH 7.5 with ammonia to produce an adhesive.

[Production of film laminate]
Using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

(Example 5)
[Manufacture of adhesive and production of film laminate]
An adhesive was produced in the same manner as in Example 4 except that 300 parts by mass of a 10% aqueous solution of polyvinyl alcohol resin (trade name “Poval M205”, manufactured by Kuraray Co., Ltd.) was used as the component (B). Furthermore, using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

(Example 6)
[Preparation of Component (A) (Aqueous Emulsion Containing Component (A))]
By the same method as in Example 1, an aqueous emulsion containing the component (A) was obtained. The solid content concentration of this aqueous emulsion was 15.1%, and the average particle diameter of the polymer particles of the component (A) was 65 nm. Table 1 shows the formulation of the component (A).

[Manufacture of adhesives]
After the aqueous emulsion containing the component (A) thus obtained was adjusted to pH 7.5 with ammonia, 15% of polyvinyl alcohol resin (trade name “Poval KL318”, manufactured by Kuraray Co., Ltd.) was used as the component (B). 200 parts by mass of the aqueous solution and 3 parts by mass of (C) a water-soluble epoxy compound (trade name “Denacol EX-421”, manufactured by Nagase ChemteX Corporation) were added to produce an adhesive.

[Production of film laminate]
Using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

(Comparative Example 1)
[Preparation of monomer component (5)]
60 parts by mass of methyl methacrylate as a monomer for a comparative example, 34 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, and 3 parts by mass of methacrylic acid as a monomer (A-2) Body component (5) was prepared. In Comparative Example 1, the monomer (A-1) having an alicyclic structure is not used.

(Preparation of aqueous emulsion)
Except for using the monomer component (5), the monomer component (5) was polymerized in the same manner as in Example 1 to obtain a copolymer of the monomer component (5). An aqueous emulsion containing was obtained. The solid content concentration of the aqueous emulsion was 15.2%, and the average particle size of the polymer particles was 62 nm. The formulation is shown in Table 1.

[Production of adhesive and production of film laminate]
An adhesive was produced by the same method as in Example 1 except that the aqueous emulsion obtained by the above method was used. Furthermore, using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured. The measurement results are shown in Table 1.

(Comparative Example 2)
[Preparation of Component (A) (Aqueous Emulsion Containing Component (A))]
By the same method as in Example 1, an aqueous emulsion containing the component (A) was obtained. The solid content concentration of this aqueous emulsion was 15.1%, and the average particle diameter of the polymer particles of the component (A) was 65 nm. Table 1 shows the formulation of the component (A).

[Manufacture of adhesive and production of film laminate]
Without using the polyvinyl alcohol resin as component (B), the aqueous emulsion was adjusted to pH 7.5 with ammonia to produce an adhesive. Furthermore, using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured.

(Comparative Example 3)
[Manufacture of adhesives]
A polyvinyl alcohol resin (trade name “GOHSENOL GL-03”, manufactured by Nippon Synthetic Chemical Co., Ltd.) was dissolved in water to give a 15% aqueous solution, and the adhesive of Comparative Example 3 was used.

[Production of film laminate]
Using the obtained adhesive, a film laminate was produced in the same manner as in Example 1, and the adhesive strength of the adhesive was measured.

(result)
As shown in Table 1, the adhesives of Examples 1 to 6 all had a high adhesive force with an adhesive force of 3 N / 25 mm or more. In particular, Example 6 further containing (C) a water-soluble epoxy compound had extremely high adhesive strength. In addition, Examples 4 and 5 using an aqueous emulsion containing a graft-polymerized graft copolymer have higher adhesive strength than Examples 1 to 3 in which the component (A) and the component (B) are mixed. I had it.

  On the other hand, since the adhesive of Comparative Example 1 does not use the monomer (A-1) having an alicyclic structure, the adhesive strength to the norbornene-based resin film (nonpolar material) cannot be obtained, and the adhesive strength is extremely low. It was a thing. Further, since the adhesive of Comparative Example 3 is an adhesive made of a simple polyvinyl alcohol resin in an aqueous solution (that does not contain the component (A)), like the adhesive of Comparative Example 1, a norbornene resin film is used. Adhesive strength to (nonpolar material) was not obtained, and the adhesive strength was extremely low.

  Moreover, since the polyvinyl alcohol resin as the component (B) is not used in the adhesive of Comparative Example 2, the adhesive strength to the polyvinyl alcohol resin film (polar material) cannot be obtained, and the adhesive strength is extremely low. It was.

  The resin composition of the present invention can be used as a resin composition that serves as an adhesive component of an adhesive. In addition, the adhesive of the present invention can be suitably used as an adhesive for bonding adherends having different polarities such as a polar material and a nonpolar material.

  For example, an adherend made of a polar material such as a polarizing plate or a TAC film used as a liquid crystal material (for example, a polyvinyl alcohol resin or triacetyl cellulose) and a nonpolar material such as a retardation film (for example, a norbornene resin) ) Can be particularly suitably used for adhesion to an adherend comprising the above.

Claims (6)

(A) It is obtained by polymerizing a monomer component including a (meth) acrylic acid ester monomer (A-1) having an alicyclic structure and a monomer (A-2) copolymerizable with the monomer (A-1). A (meth) acrylic acid ester copolymer,
(B) containing a polyvinyl alcohol resin,
The (A) (meth) acrylic acid ester copolymer includes 0.1 to 99 parts by mass of the monomer (A-1) and 1 to 99.9 parts by mass of the monomer (A-2) (provided that the monomer ( A-1) + monomer (A-2) = 100 parts by mass) and obtained by polymerizing the monomer component,
The resin composition which contains 0.1-100 mass parts of said (B) polyvinyl alcohol resin with respect to 100 mass parts of said (A) (meth) acrylic acid ester copolymers.   The resin composition according to claim 1, which is a mixture containing the (A) (meth) acrylic acid ester copolymer and the (B) polyvinyl alcohol resin.   The resin composition according to claim 1, which is a graft copolymer obtained by graft polymerization of the (A) (meth) acrylic acid ester copolymer and the (B) polyvinyl alcohol resin.   (C) The resin composition as described in any one of Claims 1-3 which further contains a water-soluble epoxy compound.   The saponification degree of the said (B) polyvinyl alcohol resin is 50-100 mol%, The resin composition as described in any one of Claims 1-4.   The adhesive agent containing the resin composition as described in any one of Claims 1-5.