JP2009067931A - Adhesive composition and adhesive film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition and an adhesive film, each excellent in adhesiveness to a reinforcing material such as a metal and heat resistance. <P>SOLUTION: The adhesive composition comprises (A) 10-98 wt.% acrylic rubber containing a carboxyl group, (B) 2-50 wt.% silane-modified epoxy resin obtained by carrying out dealcoholization reaction of (b1) epoxy resin having 180-400 g/eq epoxy equivalent with (b2) an epoxy compound having at least one hydroxy group in one molecule and (b3) a partially condensed product of an alkoxysilane, (C) 5-90 wt.% epoxy resin, (D) 2-50 wt.% phenol resin and (E) 0.01-10 wt.% dicyandiamide, based on solid content of resin. The adhesive film is formed on a support using the adhesive composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesive composition excellent in adhesion and heat resistance to an adherend such as a metal such as stainless steel, polyimide, glass / epoxy resin composite substrate, and an adhesive film using the same.

  In recent years, not only polyimide and glass / epoxy resin composite substrates but also stainless steel (SUS), LCP (liquid crystal polymer), copper, and ceramics are used as electronic materials.

  In particular, flexible printed circuit boards (FPCs) do not have mechanical strength compared to rigid boards, so when connecting to other FPCs or rigid boards, polyimide film or glass / epoxy resin composite boards are used as reinforcing materials. To reinforce. The material of the reinforcing material is diverse, and SUS, polyimide, glass / epoxy resin composite substrate, etc. are used. An adhesive film is used to bond these reinforcing materials to the FPC. The reinforcing material is laminated by temporarily attaching the reinforcing material and the FPC using an adhesive film at a temperature of about 100 ° C. and pressing. Therefore, it is necessary for the adhesive film to suppress temporary attachment to a reinforcing material or FPC, which is an adherend, and flowability after pressing. In addition, after curing, reflow soldering heat resistance capable of handling lead-free solder is required.

  Adhesives composed of epoxy resins have been widely used for bonding these electronic materials. As such an adhesive, for example, an epoxy resin blended with a curing agent or curing aid such as an aromatic amine or diamine is known.

  Moreover, as the adhesive composition based on epoxy resin, those mainly using bisphenol A type epoxy resin are widely used, and a thermoplastic polymer and an epoxy resin curing agent are blended with bisphenol A type epoxy resin. A thermosetting adhesive composition has been proposed (Cited document 1).

  Moreover, although examination as an adhesive agent came to be performed also about epoxy resins other than a bisphenol A type epoxy resin, sufficient adhesiveness, heat resistance, etc. are not acquired (cited reference 2).

  Furthermore, as a technique for improving the heat resistance, a high Tg (glass transition temperature) of the resin has been proposed, but there is a problem that the peel adhesion strength is lowered, the film is hard and the workability is inferior. In order to sufficiently satisfy the above characteristics, it has been insufficient to improve the resin alone.

  In addition, acrylonitrile butadiene rubber, polyimide, epoxy resin, acrylic rubber, and the like have been used for bonding electronic materials. However, acrylonitrile butadiene rubber-based adhesives have the disadvantage that characteristics such as electrical resistance and peel adhesion strength tend to decrease due to thermal degradation.

  In the polyimide system, since the organic solvent used for the adhesive is a high boiling point solvent such as N-methylpyrrolidone, a large amount of the high boiling point solvent tends to remain as a residual solvent, and the heat resistance of the reflow solder is likely to be lowered. Has drawbacks. Epoxy resin adhesives are inferior in flexibility and also have low peel adhesion strength.

  Acrylic rubber adhesives that can be dissolved in low-boiling general-purpose solvents are excellent in heat deterioration resistance, drying properties, flexibility, and peel-off adhesion strength, but are only cured with isocyanates and crosslinking agents such as melamine. However, it has a drawback that the crosslink density is lower than that of epoxy and polyimide, electrical resistance cannot be obtained sufficiently, and electrical reliability is inferior. For this reason, a technique of improving these properties by blending acrylic rubber with a thermosetting resin such as an epoxy resin has problems such as inferior reflow soldering heat resistance.

  As a countermeasure, low molecular weight acrylic rubber or CTBN is used as an essential component, which improves the fluidity at the B stage and enables temporary attachment at a lower temperature. Problems such as poor solder heat resistance are likely to occur.

Japanese Examined Patent Publication No. 47-43615 Japanese Patent Laid-Open No. 3-90075

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is an adhesive composition excellent in adhesiveness to a reinforcing plate such as SUS and polyimide, and the use of the same. It is to provide an adhesive film.

As a result of earnest research to solve these problems, by using acrylic rubber containing carboxyl group, specific silane-modified epoxy resin, epoxy resin, phenol resin, curing agent as essential components, metal, polyimide, etc. The inventors have found that the adhesiveness to the reinforcing material is excellent, and have completed the present invention.
The present invention relates to an adhesive composition containing the following (A) to (E) as essential components with respect to [1] resin solids.
(A) 10 to 98% by weight of an acrylic rubber containing a carboxyl group,
(B) (b1) an epoxy resin having an epoxy equivalent of 180 to 400 g / eq, (b2) an epoxy compound having one hydroxyl group in at least one molecule, and (b3) a silane obtained by dealcoholization reaction of an alkoxysilane partial condensate 2 to 50% by weight of modified epoxy resin,
(C) 5 to 90% by weight of epoxy resin,
(D) phenol resin (D) 2 to 50% by weight,
(E) Dicyandiamide 0.01 to 10% by weight.
Moreover, this invention relates to the adhesive film using the adhesive composition as described in said [1]. This adhesive film is easy to handle if it is an adhesive film having a structure in which an adhesive film layer is laminated on a release paper.

  The adhesive film of the present invention comprises an adhesive composition comprising (A) a carboxyl group-containing acrylic rubber, (B) a silane-modified epoxy resin, (C) an epoxy resin, (D) a phenol resin, and (E) dicyandiamide as essential components. By doing so, it is possible to provide an adhesive having excellent adhesion to a reinforcing plate such as SUS or polyimide and maintaining heat resistance, flexibility, etc., and the present invention on a support substrate such as a release paper. Since the adhesive composition can be easily formed with a uniform thickness, it is excellent in workability and handling.

Hereinafter, embodiments of the present invention will be specifically described.
The present invention is an adhesive composition comprising (A) carboxyl group-containing acrylic rubber, (B) silane-modified epoxy resin, (C) epoxy resin, (D) phenol resin, and (E) dicyandiamide as essential components.
The acrylic rubber containing a carboxyl group (A) used in the present invention is composed of a vinyl monomer having an acrylic acid alkyl ester (including a methacrylic acid ester, the same shall apply hereinafter) as a main component and a carboxylic acid as a functional group. It is a copolymer containing acrylonitrile, styrene or the like as required. Examples of the alkyl acrylate ester include ethyl acrylate (including ethyl methacrylate, the same applies hereinafter), ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, acrylic acid 2 -Monomers such as ethylhexyl, undecyl acrylate, lauryl acrylate, and the like, and monomers having a hydroxyl group such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and allyl alcohol. From these, one type or two or more types can be selected and used. Examples of vinyl monomers having a carboxylic acid as a functional group include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, and maleic anhydride.

  The polymerization method of the acrylic rubber is not particularly limited, but a general suspension polymerization method can be used. For example, a dispersant such as PVA, azobisisobutyronitrile (AIBN), lauryl peroxide ( A mixture of two or more of the above acrylic monomers is dropped into a liquid in which a polymerization initiator such as LPO) is dispersed in an aqueous medium, and polymerized. The polymer is washed with purified water to remove impurities, washed with water and dried by heating to remove residual monomers and moisture. The weight average molecular weight of the polymer is preferably about 50,000 to 1,000,000.

  (A) The compounding quantity of the acrylic rubber containing a carboxyl group is 10 to 98 weight% with respect to resin solid content. More preferably, it is 40 to 80% by weight. If it is less than 10% by weight, the adhesive strength is lowered, and desired properties cannot be obtained. Moreover, when it exceeds 98 weight%, there exists a tendency for heat resistance to fall.

The (B) silane-modified epoxy resin used in the present invention comprises (b1) an epoxy resin having an epoxy equivalent of 180 to 400 g / eq, (b2) an epoxy compound having one hydroxyl group in at least one molecule, and (b3) alkoxysilane. This is a product obtained by subjecting a partial condensate to a dealcoholization reaction.
The above epoxy resin (b1) can be appropriately selected and used in accordance with the purpose within an epoxy equivalent of 180 to 400 g / eq. If it is less than 180 g / eq, the amount of the alkoxysilane partial condensate (b3) remaining in the silane-modified epoxy resin as a reaction product tends to increase or the adhesive film on the B stage tends to become brittle. If the epoxy equivalent exceeds 400 g / eq, the viscosity tends to increase during the dealcoholization reaction, so that fluidity cannot be obtained, tack is reduced, and tackiness tends to be reduced.

  The amount of the epoxy compound (b2) having at least one hydroxyl group in one molecule (hereinafter referred to as epoxy compound (b2)) is not particularly limited, and the hydroxyl group in the epoxy resin (b1) having an epoxy equivalent of 180 to 400 g / eq. What is necessary is just to determine suitably according to content of the molecule | numerator which does not have. (B) From the viewpoint of heat resistance of the silane-modified epoxy resin, when the epoxy equivalent of the epoxy resin (b1) having an epoxy equivalent of 180 to 400 g / eq is smaller than 200 g / eq, the weight / epoxy equivalent of the epoxy compound (b2) When the weight of the epoxy resin (b1) of 180 to 400 g / eq is 0.05 or more and the epoxy equivalent of the epoxy resin (b1) is 200 to 300 g / eq, the weight ratio is 0.03 or more. Yes, when the epoxy equivalent of the epoxy resin (b1) is larger than 300 g / eq, the weight ratio is preferably 0.01 or more.

  The number of epoxy groups is not particularly limited as long as the epoxy compound (b2) is an epoxy compound having at least one hydroxyl group in one molecule. As the epoxy compound (b2), the smaller the molecular weight, the better the compatibility with the epoxy resin (b1) or the alkoxysilane partial condensate (b3) having an epoxy equivalent of 180 to 400 g / eq, and the higher the heat resistance imparting effect. Therefore, those having 15 or less carbon atoms are preferable. Specific examples thereof include monoglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with water, dihydric alcohol or phenol, epichlorohydrin and glycerin, pentaerythritol, etc. Polyglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting with a trihydric or higher polyhydric alcohol, having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin and amino monoalcohol Examples thereof include an epoxy compound and an alicyclic hydrocarbon monoepoxide having one hydroxyl group in the molecule (for example, epoxidized tetrahydrobenzyl alcohol). Among these epoxy compounds, glycidol (2,3-epoxy-1-propanol) is the most excellent in terms of imparting heat resistance, and also has high reactivity with the alkoxysilane partial condensate (b3). It is.

  As the alkoxysilane partial condensate (b3) used in the present invention, a partially hydrolyzed and condensed product obtained by adding an alkoxysilane compound and water in the presence of an acid or base catalyst can be used.

  Specific examples of the alkoxysilane compound that is a constituent material of the alkoxysilane partial condensate (b3) include those generally used in the sol-gel method, and include tetramethoxysilane, tetraethoxysilane, and tetrapropoxy. Tetraalkoxysilanes such as silane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyl Alkyltrialkoxysilanes such as trimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, etc. Aryl trialkoxysilanes, or condensates thereof and the like.

  As the alkoxysilane partial condensate (b3), an epoxy resin (b1) or an epoxy compound (b2) having an epoxy equivalent of 180 to 400 g / eq can be obtained from methoxysilane among the alkoxysilane compounds as the constituent raw materials. In view of versatility, tetramethoxysilane and methyltrimethoxysilane are more preferable.

  The (B) silane-modified epoxy resin used in the present invention is obtained by subjecting an epoxy resin (b1), an epoxy compound (b2) and an alkoxysilane partial condensate (b3) having an epoxy equivalent of 180 to 400 g / eq to a dealcoholization reaction. can get. The weight ratio of the epoxy resin (b1) and epoxy compound (b2) having an epoxy equivalent of 180 to 400 g / eq and the alkoxysilane partial condensate (b3) is substantially equal to (B) the alkoxy group in the silane-modified epoxy resin. Is not particularly limited, but the total equivalent of the hydroxyl group of the epoxy resin (b1) and the hydroxyl group of the epoxy compound (b2) having an epoxy equivalent of 180 to 400 g / eq / alkoxysilane partial condensate (b3 It is preferable that the equivalent (equivalent ratio) of the alkoxy group of More preferably, it is 0.13-0.5. If the equivalent ratio is less than 0.1, unreacted alkoxysilane partial condensate (b3) increases, and if it exceeds 0.6, sufficient heat resistance cannot be obtained, which is not preferable.

  The thus obtained (B) silane-modified epoxy resin is mainly composed of the alkoxysilane partial condensate (b3) in which the alkoxy group is substituted with an epoxy resin residue or a glycidyl residue. May contain an unreacted epoxy equivalent of 180 to 400 g / eq of epoxy resin (b1), epoxy compound (b2), and alkoxysilane partial condensate (b3). As such a silane-modified epoxy resin, there is COMPOCERAN E202 (manufactured by Arakawa Chemical Industries, Ltd., epoxy equivalent 285 g / eq, active ingredient 83%), which can be suitably used.

  (B) Although the compounding quantity of a silane modified epoxy resin is the range of 2-50 weight% with respect to resin solid content, Preferably, it is the range of 10-30 weight%. If it is less than 2% by weight, heat resistance cannot be obtained, and if it exceeds 50% by weight, film formation becomes difficult at the B stage, and storage stability is significantly reduced.

  The epoxy resin (C) used in the present invention is a compound having two or more epoxy groups in the molecule, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol. Novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester epoxy resin, hydantoin epoxy resin, isocyanurate epoxy resin, two Diglycidyl etherified products of functional phenols, diglycidyl etherified products of difunctional alcohols, their halides, hydrogenated products and the like can be used. These compounds can be used alone or in combination of two or more. (C) The compounding quantity of an epoxy resin is the range of 5-90 weight% with respect to resin solid content, More preferably, it is 10-80 weight%. If it is less than 5% by weight, the desired heat resistance cannot be obtained, and if it exceeds 90% by weight, the cured film becomes too hard and the adhesive strength is lowered.

  The (D) phenol resin used in the present invention is not particularly limited in terms of the molecular weight, softening point, hydroxyl equivalent, etc. of the phenol resin, but a resol type phenol resin is preferred. The phenol resin is obtained by reacting phenol with an excess of formaldehyde and reacting with an alkali catalyst. When the resol-type phenol resin is heated or an acid is added, the reaction proceeds at room temperature and self-condenses. In the present invention, not only the self-condensation of the phenol resin but also (A) the reactivity with respect to the acrylic rubber containing a carboxyl group, the reflow solder heat resistance and the volume resistance tend to be improved. (D) The compounding quantity of a phenol resin has the preferable range of 2 to 50 weight% with respect to resin solid content. If it is less than 2% by weight, the crosslink density is lowered and sufficient reflow soldering heat resistance cannot be obtained. If it exceeds 50% by weight, the storage stability as an adhesive film is impaired, and the peel adhesion strength is lowered. Cause problems.

  (E) Dicyandiamide used in the adhesive composition of the present invention is a curing agent or curing catalyst for (B) a silane-modified epoxy resin and (E) an epoxy resin, and functions as a curing catalyst and an adhesion-imparting agent. To fulfill. Although the mechanism by which dicyandiamide imparts adhesiveness is not clear, dicyandiamide has a high polarity and is considered to interact with an adherend, for example, an oxide on the surface of a metal material. Therefore, extremely excellent metal adhesion can be exhibited.

  The compounding quantity of the dicyandiamide (D) used by this invention is 0.01 to 10 weight% with respect to 100 weight% of resin solid content. If it is less than 0.01 part by weight, sufficient curing cannot be obtained, solder heat resistance is lowered, and if it exceeds 10 parts by weight, the film becomes hard, the peel adhesion strength is lowered, and the storage stability is lowered. Cause problems.

  In addition, you may add a filler to the adhesive composition of this invention as needed. The filler can be used as long as it has an elastic modulus higher than that of the resin and is electrically insulating. For example, aluminum hydroxide, magnesium hydroxide, talc, alumina, magnesia, silica, titanium dioxide, silicic acid. Powdered fillers such as calcium, aluminum silicate, calcium carbonate, clay, silicon nitride, silicon carbide, aluminum borate, synthetic mica, short fiber fillers such as glass, asbestos, rock wool, aramid, Whisker such as silicon carbide, alumina, aluminum borate and the like can be used.

  These components are used by dissolving or dispersing in an organic solvent such as methyl ethyl ketone, toluene, methanol, N-methylpyrrolidone, N, N-dimethylformamide.

  When a filler is added, the particle size is adjusted to 10 μm or less using a ball mill or the like. When it is larger than 10 μm, when an adhesive film is formed, irregularities are generated on the film surface, and the peel adhesion strength, reflow soldering heat resistance lowering and appearance are impaired.

  The support for use in producing the adhesive film of the present invention is not particularly limited. For example, clay and polyethylene are provided on both surfaces of release paper such as fine paper, kraft paper, roll paper, and glassine paper. In addition, a coating layer of a sealing agent such as polypropylene is provided, and a silicone type, fluorine type, alkyd type release agent is applied on each coating layer, and polyethylene, polypropylene, ethylene-α -Various olefin films such as olefin copolymer, propylene-α-olefin copolymer alone, and those obtained by applying the release agent on a film such as polyethylene terephthalate, etc., but with the applied adhesive layer For reasons such as mold release force and silicone adversely affecting electrical properties, polypropylene seals are applied to both sides of the high-quality paper, and the adhesive is applied on top of it. Those using a alkyd release agent and those using an alkyd release agent on polyethylene terephthalate are preferred.

  The adhesive film can be obtained by coating the adhesive composition solution directly on the release paper (support) and drying the organic solvent. Although it does not specifically limit as a coating method, A comma coater, a reverse roll coater, etc. are mentioned. The thickness of the adhesive film after drying is appropriately changed as necessary and is not particularly limited, but is preferably in the range of 3 to 200 μm. If the adhesive film thickness is less than 3 μm, the reliability of the interlayer insulation of the adhesive layer is reduced, and if it exceeds 200 μm, the drying is insufficient and the residual solvent is increased, and there is a problem that blistering occurs when the adhesive film is cured. May occur. The drying conditions are not particularly limited, but the residual solvent content after drying is preferably 2% by weight or less. If it exceeds 2% by weight, the residual solvent may foam during curing of the adhesive film, which may cause blistering.

  As described above, the adhesive composition of the present invention can be used as a support, for example, on a release paper and used as an adhesive film. In addition, the adhesive composition can be applied to, for example, polyimide or copper foil to cover a FPC coverlay or RCC. Adhesive film layer such as (copper foil with resin), polyimide or PEN (polyethylene naphthalate), etc. are laminated on a copper foil and an adhesive with a three-layer flexible copper foil-clad laminate or FPC. It can also be suitably used as an adhesive film layer for preventing powder from falling off a prepreg that may be used.

  The field in which the adhesive composition of the present invention is used is not particularly limited, and examples thereof include the electric / electronic materials field, the automobile industry field, the aerospace field, the civil engineering / architecture field, and the like. The adhesive composition of the present invention is not limited to adhesion between metal materials such as stainless steel, but also has excellent adhesion to materials other than metals, and therefore can be used for adhesion between metal materials and other materials. it can.

Although it does not restrict | limit especially as a metal of a to-be-adhered body, Specifically, stainless steel, aluminum, iron, titanium, copper, nickel, chromium, gold | metal | money, various alloys etc. are mentioned, for example.
The adherend material other than metal is not particularly limited, and specific examples include polyimide, glass / epoxy resin composite substrate, polyethylene terephthalate, ceramic, and the like.

Next, the present invention will be specifically described with reference to examples and comparative examples.
Example 1
(1) Preparation of adhesive composition solution (A) WS023DR (manufactured by Teikoku Kagaku Sangyo Co., Ltd.) is used as an acrylic rubber containing a carboxyl group, and 60% by weight based on the resin solid content. (C) Cresol novolac as an epoxy resin Type epoxy resin YDCN703 (manufactured by Tohto Kasei Co., Ltd.) is 5% by weight based on the resin solid content, and (D) phenolic resin as resol type phenol resin TD2625 (manufactured by Gunei Chemical Industry Co., Ltd.) is 5% by weight based on the resin solid content Is dissolved and dispersed in methyl ethyl ketone so as to have a solid content of 25% by weight, and further, (B) Composeran E202 (active ingredient 83% epoxy equivalent 285 g / eq manufactured by Arakawa Chemical Industries, Ltd.) as a silane-modified epoxy resin 30% by weight was mixed with respect to the minute and stirred at room temperature (25 ° C.) for 20 minutes. Furthermore, it mixed so that it might become 0.5 weight% of (E) dicyandiamide as an epoxy resin hardening | curing agent with respect to 100 weight% of resin solid content of the said liquid mixture, and it was set as the adhesive composition solution.

(2) Preparation of adhesive film The adhesive composition described above so that the thickness of the adhesive after drying on a separator using silicon mold release agent is 25 μm on both sides of a 130 μm-thick high-quality paper. The product solution was applied and dried in a hot air dryer at 90 ° C. for 3 minutes to obtain an adhesive film.

(Example 2)
In Example 1, cresol novolac type epoxy resin YDCN703 is 20% by weight with respect to the resin solid content, silane-modified epoxy resin is 10% by weight with respect to the resin solid content, instead of resol type phenolic resin TD2625. The same operation as in Example 1 was conducted except that BKM2620 (manufactured by Showa Polymer Co., Ltd.) was changed to 20% by weight based on the resin solid content.

(Example 3)
In Example 2, 1% by weight of dicyandiamide was added to 100% by weight of resin solids, and aluminum hydroxide H42M (manufactured by Showa Denko KK) was added as a filler to 30% by weight of 100% by weight of resin solids. Was carried out in the same manner as in Example 2.

Example 4
In Example 1, 80% by weight of acrylic rubber WS023DR containing a carboxyl group with respect to the resin solid content, and EP1001 (made by Japan Epoxy Resin Co., Ltd.) of bisphenol A type epoxy resin with respect to the resin solid content instead of YDCN703 5% by weight, Composeran E202 as a silane-modified epoxy resin, 5% by weight based on the resin solid content, BKM 2620 instead of resol type phenol resin TD2625, 10% by weight based on the resin solid content, and dicyandiamide as the resin solid content 100 The same operation as in Example 1 was carried out except that the content was 0.3% by weight.

(Example 5)
In Example 1, 65% by weight of acrylic rubber WS023DR containing a carboxyl group is 65% by weight based on the resin solids, YDCN703 is 20% by weight based on the resin solids, and Composeran E202 is used as the silane-modified epoxy resin based on the resin solids. The same procedure as in Example 1 was carried out except that 5% by weight, resol type phenol resin TD2625 was 10% by weight based on the resin solid content, and dicyandiamide was 0.3% by weight based on 100% by weight of the resin solid content.

(Comparative Example 1)
In Example 1, (A) acrylic rubber WS023DR containing a carboxyl group was 90% by weight based on the resin solid content, (C) YDCN703 was 5% by weight based on the resin solid content, and (B) silane-modified epoxy resin. Composelan E202 is 0% by weight with respect to the resin solid content, (D) Resol type phenol resin TD2625 is 5% by weight with respect to the resin solid content, and (E) Dicyandiamide is 1.0% with respect to 100% by weight of the resin solid content. The same procedure as in Example 1 was performed except that the percentage was changed to%.

(Comparative Example 2)
In Example 1, instead of dicyandiamide, 2E4MZ (manufactured by Shikoku Kasei Kogyo Co., Ltd., 2-ethyl-4-methylimidazole) was changed to 1.0% by weight with respect to 100% by weight of the resin solid content. 1 was performed.

(Comparative Example 3)
In Example 1, instead of dicyandiamide, metaxylenediamine (manufactured by Mitsubishi Gas Chemical Co., Inc.) was used in the same manner as in Example 1 except that 1.0% by weight was used with respect to 100% by weight of the resin solid content.

(Comparative Example 4)
In Example 1, it carried out similarly to Example 1 except having made phthalic anhydride 1.0 weight% with respect to 100 weight% of resin solid content instead of dicyandiamide.

(Comparative Example 5)
In Example 1, in place of dicyandiamide, the same as Example 1 except that the thiol-based curing agent Adeka Hardener EH316 (manufactured by Asahi Denka Kogyo Co., Ltd.) was 2.0% by weight with respect to 100% by weight of the resin solid content. Went to.

  The results of peel adhesion strength, reflow solder heat resistance, and flowability measured by the following evaluation methods using the formulations of Examples 1 to 5 and Comparative Examples 1 to 5 and the adhesive films obtained above are shown. 1 and 2.

(Evaluation methods)
(1) Peeling adhesive strength to polyimide (PI) Adhesive film surface of a polyimide film Kapton 200H (manufactured by DuPont) with a thickness of 50 μm and a separator (release paper) is laminated on a 100 ° C. laminating roll (linear pressure 5 kg). After laminating at / cm, laminating speed 1 m / min), the separator is peeled off, and the adhesive film surface from which the separator has been peeled is further coated with a 50 μm-thick polyimide film Kapton 200H at 100 ° C. laminating roll (linear pressure 5 kg / cm And a minate speed of 1 m / min). Thereafter, pressing (temperature: 170 ° C., pressure: 1 MPa, 3 minutes) and post-curing at 150 ° C. for 2 hours was used as a test piece. The cured specimen was measured in accordance with JIS K 6854-3, and the T-peeling adhesive strength was measured. The peeling temperature was 23 ° C., and the peeling speed was 10 mm / min.
(2) Peeling adhesive strength to stainless steel (SUS) The adhesive film surface of a 25 μm thick polyimide film Kapton200H (manufactured by DuPont) and a separator (release paper) is laminated on a 100 ° C. laminating roll (linear pressure 5 kg). After laminating at a laminating speed of 1 m / min), a 0.1 mm thick stainless steel plate SUS403 was applied to the adhesive film surface from which the separator was peeled off at a laminating roll of 100 ° C. (linear pressure 5 kg / cm, laminating Bonding was performed at a speed of 1 m / min). Thereafter, pressing (temperature: 170 ° C., pressure: 1 MPa, 3 minutes) and post-curing at 150 ° C. for 2 hours was used as a test piece. The cured specimen was measured in accordance with JIS K 6854-3, and the T-peeling adhesive strength was measured. The peeling temperature was 23 ° C., and the peeling speed was 10 mm / min.
(3) Peeling adhesive strength to glass / epoxy composite substrate (glass epoxy substrate, GE) Adhesive film surface of adhesive film with 25 μm thick polyimide film Kapton200H (manufactured by DuPont) and separator (release paper) After laminating with a laminating roll (linear pressure 5 kg / cm, laminating speed 1 m / min), a glass / epoxy composite substrate having a thickness of 0.3 mm was laminated at 100 ° C. on the adhesive film surface from which the separator was peeled off. Bonding was performed with a roll (linear pressure 5 kg / cm, laminating speed 1 m / min). Thereafter, pressing (temperature: 170 ° C., pressure: 1 MPa, 3 minutes) and post-curing at 150 ° C. for 2 hours was used as a test piece. The cured specimen was measured in accordance with JIS K 6854-3, and the T-peeling adhesive strength was measured. The peeling temperature was 23 ° C., and the peeling speed was 10 mm / min.
(4) Reflow solder heat resistance After bonding the adhesive film surface of a 35 μm thick rolled copper foil and a separator with a laminating roll (linear pressure 5 kg / cm, laminating speed 1 m / min) at 100 ° C. The above-mentioned separator was peeled off, and a 35 μm-rolled copper foil was further bonded to the adhesive film surface from which the separator was peeled off by a laminating roll (linear pressure 5 kg / cm, laminating speed 1 m / min) at 100 ° C. Thereafter, pressing (temperature: 170 ° C., pressure: 1 MPa, 3 minutes) and post-curing at 150 ° C. for 2 hours was used as a test piece. According to JIS C 6481, the test piece was left in a humidified condition (temperature: 40 ° C., relative humidity: 80%) for 12 hours, and then a reflow soldering apparatus (manufactured by Nippon Pulse Laboratories, RF430) was used. The test piece was heated so that the maximum surface temperature was 260 ° C., and the presence or absence of swelling of the adhesive layer was observed. Those that were not swollen and peeled were evaluated as “◯”, and those that were swollen and peeled were evaluated as “x”.

(5) Flowability After bonding the polyimide film Kapton 100H with a thickness of 25 μm and the adhesive film surface of the adhesive film with a separator with a laminating roll at 100 ° C. (linear pressure 5 kg / cm, laminating speed 1 m / min), The separator was peeled off, and a 25 μm polyimide film Kapton 100H was further bonded to the adhesive film surface from which the separator had been peeled off by a 100 ° C. laminating roll (linear pressure 5 kg / cm, laminating speed 1 m / min). The said test piece was cut out to 80 mm x 80 mm, and the press (160 degreeC, 3 Mpa, 20 minutes) was performed. Thereafter, the maximum protruding portion on each of the four sides was measured with a caliper, and the average was taken as the flow-out amount (mm). The evaluation of the flow-out amount was evaluated as “◯” when it was less than 0.5 mm, and “x” when it was 0.5 mm or more.

表中の部数は溶剤を除いた重量％比

The parts in the table are weight% ratios excluding solvent.

表中の部数は溶剤を除いた有効成分の重量％比

The number of parts in the table is the weight% ratio of active ingredients excluding solvent.

The present invention is an adhesive composition comprising (A) a carboxyl group-containing acrylic rubber, (B) a silane-modified epoxy resin, (C) an epoxy resin, (D) a phenol resin, and (E) dicyandiamide, As shown in the comparative examples, when (B) no silane-modified epoxy resin is used (Comparative Example 1) and (E) dicyandiamide is not used as a curing agent (Comparative Examples 2, 3, and 4), reflow soldering is used. Inferior in heat resistance, swelling and peeling occurred. Moreover, when pressed, the adhesive layer is inferior in the ability to flow out too much. Furthermore, the peel adhesion strength is 6 to 8 N / m for glass / epoxy composite substrate, 5 to 7 N / m for polyimide film, and 3 to 6 N / m for stainless steel. Adhesiveness to is poor. On the other hand, in the adhesive film using the adhesive composition of the present invention, the reflow soldering heat resistance and the flow-out property are good, and the peel adhesion strength is 12 to 15 N / m with respect to the glass / epoxy composite substrate, 10-12 N / m for polyimide film, 10-12 N / m for stainless steel, and excellent adhesion to comparative examples, and adhesion of polyimide and stainless steel to glass / epoxy composite substrate is almost equivalent. The degree of adhesion is excellent.
According to the present invention, (A) an acrylic rubber containing a carboxyl group, (B) a specific silane-modified epoxy resin, (C) an epoxy resin, (D) a phenol resin, and (E) dicyandiamide are used as essential components. An adhesive composition excellent in adhesion to a reinforcing plate such as metal and heat resistance, and an adhesive film using the same can be provided.

Claims (2)

The adhesive composition which contains the following (A)-(E) as an essential component with respect to resin solid content.
(A) 10 to 98% by weight of an acrylic rubber containing a carboxyl group,
(B) (b1) an epoxy resin having an epoxy equivalent of 180 to 400 g / eq, (b2) an epoxy compound having one hydroxyl group in at least one molecule, and (b3) a silane obtained by dealcoholization reaction of an alkoxysilane partial condensate 2 to 50% by weight of modified epoxy resin,
(C) 5 to 90% by weight of epoxy resin,
(D) 2-50% by weight of phenolic resin,
(E) Dicyandiamide 0.01 to 10% by weight An adhesive film using the adhesive composition according to claim 1.