JPH10147756A - Production of epoxy adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an epoxy adhesive film which can form a film excellent in heat resistance and chemical resistance. SOLUTION: The production process comprises mixing a film-forming high- molecular-weight epoxy polymer obtained by polymerizing a mixture obtained by mixing a halogenated bifunctional epoxy resin with a halogenated phenol in an epoxy/phenolic hydroxyl ratio of 1/0.9 to 1/1.1 by heating in the presence of a catalyst in an amide solvent and a weight-average molecular weight of 50,000 or above (in terms of the polystyrene as measured by gel permeation chromatography(GPC)) with a masked isocyanate prepared by masking the isocyanate groups of an isocyanate having at least two isocyanate groups, a polyfunctional epoxy resin and a curing agent, coating at least either surface of a supporting film with the obtained mixture and removing the solvent from the wet film by drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an epoxy adhesive film.

[0002]

2. Description of the Related Art With respect to high molecular weight epoxy polymers, for example, US Pat. No. 3,277,048 discloses a bifunctional epoxy resin having a molecular weight of 30,30 obtained by reacting a brominated bisphenol or a chlorinated bisphenol. It is described that a flame-retardant epoxy resin cured product having good mechanical properties is obtained by blending 2,000 or more thermoplastic resins. The polymer obtained in Examples has a molecular weight of 61,000, and the obtained sheet Has a thickness of 0.125 inch (about 3 mm).

[0003] A method for producing a high-molecular-weight epoxy polymer from a relatively low-molecular-weight bifunctional epoxy resin and a bifunctional phenol as raw materials is generally called a two-stage method.
U.S. Pat. No. 2,615,008 discloses that sodium hydroxide is used as a polymerization catalyst, and 150 to 20 without solvent.
By reacting at 0 ° C., the epoxy equivalent is 5,60.
It is stated that a high molecular weight epoxy polymer of 0 is obtained.

In US Pat. No. 3,306,872, methyl ethyl ketone or ethylene glycol monomethyl ether is used as a solvent, the solid content of the solution is 20 to 60%, and an alkali metal or benzyltrimethyl ammonium is used as a catalyst. Using a hydroxide or phenolate, the polymerization reaction temperature is 75 to 150 ° C.,
The weight average molecular weight of the produced high molecular weight epoxy polymer is 50,000 to 100,000 as measured by a viscosity method.

Further, Japanese Patent Application Laid-Open No. 54-52200 discloses that
It is described that a high molecular weight epoxy polymer having an average molecular weight of 45,500 was obtained using ethylene glycol monoethyl ether as a solvent. Japanese Patent Application Laid-Open No. 60-118575 discloses methyl isobutyl ketone, cyclohexanone, ethylene glycol as a solvent. It is described that a high molecular weight epoxy polymer having an average molecular weight of 31,000 at the maximum was obtained using monoethyl ether.
No. 23, using methyl ethyl ketone as a solvent,
It was described that a high molecular weight epoxy polymer having an average molecular weight of 53,200 was obtained. Japanese Patent Application Laid-Open No. 60-144324 discloses that a high molecular weight epoxy polymer having an average molecular weight of 66,000 was obtained using methyl ethyl ketone as a solvent. Is described. In all four cases, the average molecular weight was measured by gel permeation chromatography.

A method for producing an epoxy resin sheet using a high molecular weight epoxy polymer is disclosed in Japanese Patent Application Laid-Open No. 51-8 / 1981.
As disclosed in Japanese Patent No. 7560, a linear high-molecular-weight epoxy polymer and a low-molecular-weight epoxy resin are heated and melted, and an organic carboxylate is mixed.
Methods for producing 5 mm sheets are known. The resulting sheet has a tensile strength of about 10 MPa and an elongation of 350
870%, and the molecular weight of the linear high molecular weight epoxy polymer is 30,000-250,000.

[0007] As a method for imparting thermosetting properties by reacting isocyanates with hydroxyl groups in a polymer, 1947
By Otto Bayer (O.Bayer: Das Di-i)
socyanat-Polyadditionsverfahren: Angewandte Chemie,
A59,257,1947). A method of obtaining a cured product by mixing isocyanates with an epoxy resin is described in US Pat. No. 2,594,979.

A method for crosslinking a high molecular weight epoxy polymer using isocyanates as a crosslinking agent is disclosed in
As described in JP-A-5-40752, it is known to blend a polyisocyanate with a methyl ethyl ketone solution (solid content concentration: 35%) of a phenoxy resin having an average molecular weight of 50,000 to 150,000.

[0009] JP-A-54-117597, JP-B-1-19816 and JP-A-2-147616 disclose epoxy resins and high-molecular-weight phenoxy resins.
Alternatively, a method using an unsaturated isocyanate or a masked isocyanate in a mixture thereof is disclosed.

[0010] Japanese Patent Publication No. 1-19806 discloses that a phenoxy resin is modified with an unsaturated isocyanate to give a film-forming ability to obtain a cured film.

The method of inactivating the active isocyanate groups of the isocyanates at room temperature by masking (blocking) is described in the above-mentioned article by Otto Bayer in 1947.

A halogenated bifunctional epoxy resin and a halogenated bifunctional phenol are blended so that the ratio of epoxy group / phenol hydroxyl group is 1 / 0.9 to 1 / 1.1. Gel permeation chromatography (GPC) with film-forming ability obtained by heating and polymerizing at room temperature
High-molecular-weight epoxy polymers having a styrene-equivalent weight average molecular weight of 50,000 or more according to the method described in JP-A-4-120124, JP-A-4-120125, JP-A-5-93041, and Japanese Patent Laid-Open No. 5-
It is disclosed by Japanese Patent No. 93042.

[0013]

Among the prior art, the molecular weight obtained by reacting a bifunctional epoxy resin with a brominated bisphenol or chlorinated bisphenol described in US Pat. No. 3,277,048. A method of obtaining a flame-retardant epoxy resin cured product having good mechanical properties by blending 30,000 or more thermoplastic resins does not use a solvent at the time of synthesis. In this method, a film having sufficient strength is used. A high molecular weight epoxy polymer having a high molecular weight was not obtained until it had a forming ability, and the molecular weight of the polymer obtained in Examples was set to 61,000, but the measurement method was not described. , The numbers are not reproducible.

[0014] For example, in US Pat. No. 2,615,008, which is referred to as a two-stage method, no solvent is used in the synthesis, and the average molecular weight of the polymer is estimated to be about 11,000. Is done. In this method, a high-molecular-weight epoxy polymer having a linearly increased molecular weight cannot be obtained until the film has sufficient strength to form a film.

The viscosity method described in US Pat. No. 3,306,872 for measuring the weight average molecular weight of the produced high molecular weight epoxy polymer largely depends on the setting of parameters used in the calculation, It is not an accurate measurement method and has no reproducibility.

Further, Japanese Patent Application Laid-Open Nos. 54-52200, 60-118575 and 60-1443 are disclosed.
The average molecular weight described in JP-A No. 23 and JP-A-60-144324 is measured by gel permeation chromatography, but the measurement conditions and the calculation method are not described, and there is no reproducibility.

The method of producing an epoxy resin sheet using a high molecular weight epoxy polymer, disclosed in Japanese Patent Application Laid-Open No. 51-87560, does not disclose a method for synthesizing a high molecular weight epoxy polymer. The method for measuring the molecular weight is not clear.

Japanese Patent Publication No. 1-19806 discloses that a phenoxy resin is modified with an unsaturated isocyanate to give a film-forming ability to obtain a cured film. Since the phenoxy resin used is dissolved in methyl ethyl ketone, the phenoxy resin referred to here has no film-forming ability, and even in this method, the phenoxy resin has a high linearity until it has sufficient strength to form a film. A high molecular weight epoxy polymer having a reduced molecular weight cannot be obtained.

A high-molecular-weight epoxy polymer having a weight-average molecular weight in terms of styrene of 50,000 or more by gel permeation chromatography (GPC) and a method for producing the same are described in JP-A-4-120124 and JP-A-4-120125. JP-A-5-93041 and JP-A-5-9
Although disclosed by Japanese Patent No. 3042, the high molecular weight epoxy polymer obtained by this method is thermoplastic and has sufficient strength, but has a problem that heat resistance and chemical resistance are low.

An object of the present invention is to provide a method for producing an epoxy adhesive film having excellent heat resistance and chemical resistance and having a film forming ability.

[0021]

The method for producing an epoxy adhesive film of the present invention comprises the steps of preparing a halogenated bifunctional epoxy resin and a halogenated bifunctional phenol by epoxy group / phenol hydroxyl group = 1 / 0.9 to 1/1. The polymer was heated and polymerized in a solvent in the presence of a catalyst to obtain a film-forming gel-permeation chromatography (GPC) method having a weight average molecular weight in terms of styrene of 5 by gel permeation chromatography (GPC).
After blending a masked isocyanate obtained by masking an isocyanate group of isocyanates having two or more isocyanate groups, a polyfunctional epoxy resin, and a curing agent into a high molecular weight epoxy polymer of 0000 or more, It is characterized in that it is applied on one or both sides and the solvent is removed by drying.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the halogenated bifunctional epoxy resin used in the present invention, a halogen atom is replaced by a hydrogen atom,
Moreover, compounds having two epoxy groups in the molecule, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin,
An alicyclic epoxy resin, an aliphatic chain epoxy resin, a diglycidyl ether compound of a bifunctional phenol, a halide of a diglycidyl ether compound of a bifunctional alcohol, or the like can be used.

The halogenated bifunctional phenols include compounds in which a halogen atom is substituted with a hydrogen atom and which has two phenolic hydroxyl groups in the molecule, for example, hydroquinone, resorcinol, which is a monocyclic bifunctional phenol, Catechol, bisphenol A which is a polycyclic bifunctional phenol, bisphenol F, naphthalene diols,
Biphenols and their alkyl-substituted halides can be used. Two or more of these compounds can be used in combination.

The equivalent ratio of the halogenated difunctional epoxy resin to the halogenated bifunctional phenol is in the range of epoxy group / phenolic hydroxyl group = 1 / 0.9 to 1 / 1.1.
In this equivalent ratio, when the phenolic hydroxyl group is less than 0.9, the polymer does not linearly increase in molecular weight, causes a side reaction to be crosslinked, and becomes insoluble in a solvent. Does not progress.

As the polymerization catalyst for the halogenated bifunctional epoxy resin and the halogenated bifunctional phenol, those having a catalytic activity for accelerating the reaction between an epoxy group and a phenolic hydroxyl group, for example, an alkali metal compound and an alkaline earth metal Compounds, imidazoles, organic phosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like can be used. Among them, alkali metal compounds are the most preferred catalysts because side reactions are unlikely to occur and the molecular weight is high, and hydroxides of sodium, lithium and potassium, halides, organic acid salts, alcoholates, phenolates, hydrides, Examples include borohydrides and amides. These catalysts can be used in combination. The amount of the catalyst
Generally, 0.0001 to 1 mole of epoxy resin.
It is about 0.2 mol. If the amount is less than 0.0001 mol, the polymerization reaction becomes extremely slow, and if it exceeds 0.2 mol, it is difficult to form a linear polymer.

The amide solvent used in the present invention can dissolve a halogenated bifunctional epoxy resin and a halogenated bifunctional phenol, for example, formamide, N-methylformamide, N, N-dimethylformamide, Acetamide, N-methylacetamide, N,
N-dimethylacetamide, N, N, N ', N'-tetramethylurea, 2-pyrrolidone, N-methylpyrrolidone, carbamic acid esters and the like can be used. These solvents can be used in combination, and further can be used in combination with other ketone solvents or ether solvents.

The solid content concentration in the polymerization reaction using a solvent must be in the range of 10 to 50% by weight.
If the amount is less than 10% by weight, the solution viscosity at the time of application becomes extremely low, and application becomes impossible. If it exceeds 50% by weight, side reactions increase and it is difficult to increase the molecular weight into a linear one. The tendency for the side reaction to increase is likely to occur as the solid content concentration increases, and is preferably 40% by weight or less, more preferably 30% by weight or less.

The polymerization reaction temperature must be 60 to 150 ° C. If it is lower than 60 ° C., the high molecular weight reaction is remarkably slow, and if it exceeds 150 ° C., side reactions increase and it is difficult to increase the molecular weight into a linear one. .

The isocyanates used in the present invention include those having two isocyanate groups in the molecule, for example,
Diisocyanates include hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, phenylene diisocyanate, tolylene diisocyanate,
Trimethylhexamethylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, diphenylpropane diisocyanate, biphenyl diisocyanate, and isomers, alkyl substitutes, halides, hydrogenated benzene rings thereof, and the like can be used. Further, triisocyanates having three isocyanate groups, tetraisocyanates having four isocyanate groups, and the like can be used, and these can be used in combination.

When an isocyanate is used as a crosslinking agent, the reactivity with an alcoholic hydroxyl group is so high that the crosslinking reaction proceeds at room temperature and gelation of the epoxy resin solution may occur. In the present invention, this isocyanate group is used as a mask (block). Examples of the isocyanate masking (blocking) agent include compounds having active hydrogen that reacts with isocyanate groups, such as ketone oximes, alcohols, phenols, and amines. Ketone oximes include acetone oxime, methyl ethyl ketone oxime, methyl isobutyl oxime, cyclohexanone oxime and the like, and alcohols include methyl alcohol, ethyl alcohol, n-
There are monofunctional alcohols such as propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, pentanol, hexanol, and cyclohexanol, and bifunctional alcohols such as ethylene glycol, propylene glycol, and butylene glycol. Phenol, cresol,
Xylenol, trimethylphenol, butylphenol, phenylphenol, monofunctional phenols such as naphthol, hydroquinone, resorcinol, catechol,
Bisphenol A, Bisphenol F, Biphenol,
Naphthalene diol, dihydroxy diphenyl ether, bifunctional phenols such as dihydroxy diphenyl sulfone and isomers and halides thereof, pyrogallol,
Hydroxyhydroquinone, phloroglucin, phenol novolak, cresol novolak, bisphenol A
Novolak, naphthol novolak, polyfunctional phenols such as resole, etc., as amines, n-propylamine, isopropylamine, n-butylamine,
Isobutylamine, benzylamine, triethylenediamine, imidazole, benzimidazole, nitroimidazole, caprolactam, butyrolactam, and isomers thereof, alkyl-substituted products, halides, hydrochlorides,
Carboxylate and the like. This mask (block) agent
Several types can be used in combination. It is necessary to use this mask (blocking) agent so that the active hydrogen of the masking (blocking) agent is 0.5 to 3.0 equivalents to 1.0 equivalent of isocyanate groups of isocyanates. If the amount is less than 0.5 equivalent, the mask (block) becomes incomplete, and the possibility that the high molecular weight epoxy polymer gels increases. If the amount exceeds 3.0 equivalents, the mask (block) agent becomes excessive, A mask (blocking) agent remains on the formed film, and reduces heat resistance and chemical resistance.

The isocyanates can be used by dissolving them in acetylacetone, have an effect of inactivating the isocyanates at room temperature, and can improve the storage stability of the varnish. Further, when a solution prepared by dissolving isocyanates with acetylacetone is heated at room temperature to 130 ° C. and stirred for 10 minutes to 10 hours, the storage stability of the varnish can be further enhanced. Further, it is easy to volatilize when dried, and the ratio of remaining on the film is small. The concentration of the isocyanates dissolved in acetylacetone is preferably in the range of 10 to 90% by weight. If it is less than 10% by weight, the amount of acetylacetone used is too large to be economical. If it exceeds 90% by weight, the effect of inactivating the isocyanates is reduced.

The amount of the isocyanate dissolved in acetylacetone or the isocyanate dissolved in the high-molecular-weight epoxy polymer is 0.1 equivalent of the isocyanate group equivalent to 1 equivalent of the alcoholic hydroxyl group of the high-molecular-weight epoxy polymer.
It is preferably in the range of 1-2. If it is less than 0.1, crosslinking is difficult, and if it exceeds 2, isocyanates remain in the film, lowering heat resistance and chemical resistance.

The polyfunctional epoxy resin used in the present invention includes:
Compounds having two or more epoxy groups in the molecule, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin,
Phenol novolak epoxy resin, cresol novolak epoxy resin, bisphenol A novolak epoxy resin, bisphenol F novolak epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin,
Glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, diglycidyl etherified product of bifunctional phenols, diglycidyl etherified product of difunctional alcohols, and their halides, hydrogen Additives and the like can be used. These compounds may be used in combination of two or more, and may also contain components other than the bifunctional epoxy resin as impurities. The blending amount of the polyfunctional epoxy resin with respect to the high molecular weight epoxy polymer is in the range of 1 to 200 parts by weight based on 100 parts by weight of the high molecular weight epoxy polymer.

Typical examples of the curing agent for the polyfunctional epoxy resin include polyfunctional phenols, amines, imidazole compounds, and acid anhydrides. Polyfunctional phenols include monocyclic bifunctional phenol hydroquinone, resorcinol, catechol, polycyclic bifunctional phenol bisphenol A, bisphenol F, naphthalene diols, bisphenols and their halides, alkyl-substituted products, Novolak resins and resole resins which are polycondensates of these phenols and aldehydes can be used. Examples of the amines include aliphatic primary amines, secondary amines, tertiary amines, and aromatic primary amines. Secondary amines, tertiary amines, guanidines, urea derivatives, etc., specifically, triethylenetetramine, diaminodiphenylmethane, diaminodiphenylether,
Dicyandiamide, tolylbiguanide, guanylurea,
Dimethyl urea and the like can be used.
Alkyl-substituted imidazole, benzimidazole and the like can be used, and as the acid anhydride, phthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride and the like can be used. If necessary, a curing accelerator is used, for example, a tertiary amine, imidazole, quaternary ammonium salt, or the like. The compounding amount of the curing agent is 1 to 70 parts by weight based on 100 parts by weight of the polycyclic epoxy resin. In addition, if necessary,
Flame retardants and inorganic fillers can also be blended. Examples of flame retardants include bromine compounds such as tetrabromobisphenol A, decabromodiphenyl ether, brominated epoxy resins, and brominated phenol resins, and aluminum hydroxide, magnesium hydroxide, and the like. Can be used.

These high molecular weight epoxy polymers, masked isocyanates or isocyanates dissolved in acetylacetone, a polyfunctional epoxy resin, a curing agent, and a curing accelerator are mixed so that the varnish does not gel.

The support film to which the varnish is applied includes:
Those that do not dissolve in the amide solvent used for the varnish, for example, a polyimide film, a polyester film, a polyethylene film, a polypropylene film, and the like can be used.In addition, instead of this support film, a copper foil is used, and the surface to be coated is roughened. It can also be a surface. The drying performed after applying the varnish is performed at a temperature lower than the composition of the varnish to be used or the decomposition temperature of the support film.

[0037]

【Example】

Example 1 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. / Phenolic hydroxyl group = 1 / 1.02, lithium hydroxide as a catalyst in epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a film-forming ability and having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) was obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g in N, N-dimethylacetamide at 30 ° C. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and 1.0 equivalent of methyl ethyl ketone oxime is used as a masking agent for 1.0 equivalent of the isocyanate group. It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the epoxy polymer. Cresol novolak type epoxy resin (epoxy equivalent: 195) was used as a polyfunctional epoxy resin with respect to 100 parts by weight of the high molecular weight epoxy polymer.
0 parts by weight and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent were blended to obtain a varnish. This varnish was applied on one side of a polypropylene film having a thickness of 50 μm, and dried in a dryer at 100 ° C. for 0.5 h.
Drying was performed under the conditions of r to obtain a semi-cured epoxy adhesive film having a thickness of 42 μm.

Example 2 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated difunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.0, and sodium hydroxide as a catalyst was added to the epoxy resin 1
N, as a solvent in the presence of 0.06 mol
Using N-dimethylacetamide, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 32%.
A polymer having a weight average molecular weight of 133,000 in terms of styrene by gel permeation chromatography (GPC) having a film forming ability obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours at 120 ° C. An epoxy polymer was obtained whose reduced viscosity was 1.32 dl / g at 30 ° C. in N, N-dimethylacetamide. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and 1.0 equivalent of methyl ethyl ketone oxime is used as a masking agent for 1.0 equivalent of the isocyanate group. It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the epoxy polymer. Cresol novolak type epoxy resin (epoxy equivalent: 195) was used as a polyfunctional epoxy resin with respect to 100 parts by weight of the high molecular weight epoxy polymer.
0 parts by weight and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent were blended to obtain a varnish. This varnish was applied on one side of a polypropylene film having a thickness of 50 μm, and dried in a dryer at 100 ° C. for 0.5 h.
Drying was performed under the conditions of r to obtain a semi-cured epoxy adhesive film having a thickness of 43 μm.

Example 3 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
N in the presence of 0.065 moles per mole of N
-Methylpyrrolidone, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 340 mP.
high molecular weight having a weight average molecular weight of 175,000 as determined by gel permeation chromatography (GPC) having a film-forming ability obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. An epoxy polymer was obtained having a reduced viscosity of 1.18 dl / g at 30 ° C. in N, N-dimethylacetamide. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and 1.0 equivalent of methyl ethyl ketone oxime is used as a masking agent for 1.0 equivalent of the isocyanate group. It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent for 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained. This varnish was applied on one side of a polypropylene film having a thickness of 50 μm, and dried in a drier at 100 ° C. for 0.5 hours to obtain a semi-cured epoxy adhesive film having a thickness of 44 μm.

Example 4 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a film-forming ability and having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) was obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g at 30 ° C. in N, N-dimethylacetamide. In this high-molecular-weight epoxy polymer, tolylene diisocyanate is used as an isocyanate having two or more isocyanate groups, and 1.0 equivalent of phenol is used as a masking agent with respect to 1.0 equivalent of the isocyanate group.
It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of high molecular weight epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 100 parts by weight of a high molecular weight epoxy polymer, and a phenol novolak resin (hydroxyl equivalent: 10) as a curing agent
6) was blended in an amount of 20 parts by weight to obtain a varnish. This varnish was applied on one side of a 50 μm thick polypropylene film, and dried in a dryer at 100 ° C. for 0.5 hr to obtain a 45 μm thick semi-cured epoxy adhesive film.

Example 5 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a film-forming ability and having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) was obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g at 30 ° C. in N, N-dimethylacetamide. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in this high molecular weight epoxy polymer, and phenol novolak is used as a masking agent for 1.0 equivalent of the isocyanate group.
Five equivalents were used, and it was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the high molecular weight epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 209 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent are added to 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained.
This varnish was applied to one side of a 50 μm thick polypropylene film, and dried in a drier at 100 ° C. for 0.5 hr to obtain a 48 μm thick semi-cured epoxy adhesive film.

Example 6 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a film-forming ability and having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) was obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g at 30 ° C. in N, N-dimethylacetamide. A 40% by weight solution of isophorone diisocyanate dissolved in acetylacetone was added to this high molecular weight epoxy polymer,
It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of high molecular weight epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 100 parts by weight of a high molecular weight epoxy polymer, and a phenol novolak resin (hydroxyl equivalent: 10) as a curing agent
6) was blended in an amount of 20 parts by weight to obtain a varnish. This varnish was applied on one side of a 50 μm thick polypropylene film, and dried in a dryer at 100 ° C. for 0.5 hr to obtain a 45 μm thick semi-cured epoxy adhesive film.

Example 7 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated difunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high-molecular-weight epoxy polymer having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) having a film-forming ability obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g at 30 ° C. in N, N-dimethylacetamide. To this high molecular weight epoxy polymer, a 40% by weight solution of isophorone diisocyanate dissolved in acetylacetone was added.
The mixture heated at 20 ° C. for 8 hours was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the high molecular weight epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent for 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained. This varnish was applied to one side of a 50 μm-thick polypropylene film, and dried in a drier.
Drying was performed at 0 ° C. for 0.5 hour to obtain a semi-cured epoxy adhesive film having a thickness of 43 μm.

Example 8 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a film-forming ability and having a weight average molecular weight in terms of styrene of 155,000 by gel permeation chromatography (GPC) was obtained by heating and polymerizing in a solvent at 120 ° C. for 10 hours. The reduced viscosity was 1.22 dl / g at 30 ° C. in N, N-dimethylacetamide. A 40% by weight solution of isophorone diisocyanate dissolved in acetylacetone was added to this high molecular weight epoxy polymer,
It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of high molecular weight epoxy polymer. 30 parts by weight of a brominated bisphenol A type epoxy resin (epoxy equivalent: 400) as a polyfunctional epoxy resin and 100 parts by weight of a high molecular weight epoxy polymer, and a phenol novolak resin (hydroxyl equivalent: 10) as a curing agent
6) was blended in an amount of 20 parts by weight to obtain a varnish. This varnish was applied on one side of a 50 μm thick polypropylene film, and dried in a dryer at 100 ° C. for 0.5 hr to obtain a 45 μm thick semi-cured epoxy adhesive film.

Comparative Example 1 A phenoxy resin, YP, was added to a high molecular weight epoxy polymer.
50 (manufactured by Toto Kasei Co., Ltd., trade name, average molecular weight; 6)
8,000), using isophorone diisocyanate as an isocyanate having two or more isocyanate groups.
As a masking agent, methyl ethyl ketone oxime was added in an amount of 1.0
It was used in an amount equivalent to 0.5 equivalent of an isocyanate group per 1 equivalent of an alcoholic hydroxyl group of a high molecular weight epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent for 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained. This varnish was applied on one surface of a polypropylene film having a thickness of 50 μm, and dried in a drier at 100 ° C. for 0.5 hr to obtain a semi-cured epoxy adhesive film having a thickness of 42 μm. However, this adhesive film was brittle and difficult to handle, and could not be evaluated.

Comparative Example 2 A brominated bisphenol A type epoxy resin (epoxy equivalent: 400) was used as a halogenated bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated bifunctional phenol. , Epoxy group / phenol hydroxyl group = 1 / 1.02, and lithium hydroxide as a catalyst was added to the epoxy resin 1
Using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol with respect to the mol, the composition was adjusted so that the solid concentration of the solution was 30% by weight, and the viscosity was 350 mPa · s. A high molecular weight epoxy polymer having a weight average molecular weight in terms of styrene of 155,000 as determined by gel permeation chromatography (GPC) having a film-forming ability obtained by heating and polymerizing in the solvent was obtained. 30 ° C in N, N-dimethylacetamide
Was 1.22 dl / g. Isophorone diisocyanate alone is used as the isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and the alcoholic hydroxyl group 1 of the high molecular weight epoxy polymer is used.
The isocyanate group was blended so as to be 0.5 equivalent to the equivalent. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent for 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained. This varnish gelled in 3 hours, and a film could not be obtained.

Comparative Example 3 A bisphenol A type epoxy resin (epoxy equivalent: 171) was used as a bifunctional epoxy resin, and bisphenol A (hydroxyl equivalent: 11) was used as a bifunctional phenol.
Using 4), epoxy group / phenol hydroxyl group = 1/1.
01, and using N, N-dimethylacetamide as a solvent in the presence of 0.065 mol of lithium hydroxide as a catalyst with respect to 1 mol of epoxy resin,
The composition was adjusted so that the solid content concentration of the solution was 20% by weight, the viscosity was 6,800 mPa · s, and gel permeation chromatography (GPC) having a film-forming ability obtained by heating and polymerizing in a solvent was used. A) a high molecular weight epoxy polymer having a weight average molecular weight in terms of styrene of 185,000 by the method was obtained, and its reduced viscosity was 1.08 dl / g in N, N-dimethylacetamide at 30 ° C. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and 1.0 equivalent of methyl ethyl ketone oxime is used as a masking agent for 1.0 equivalent of the isocyanate group. It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the epoxy polymer. Cresol novolak type epoxy resin (epoxy equivalent: 195) was used as a polyfunctional epoxy resin with respect to 100 parts by weight of the high molecular weight epoxy polymer.
0 parts by weight and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent were blended to obtain a varnish. This varnish was applied on one side of a polypropylene film having a thickness of 50 μm, and dried in a dryer at 100 ° C. for 0.5 h.
Drying was performed under the conditions of r to obtain a semi-cured epoxy adhesive film having a thickness of 38 μm.

Comparative Example 4 A bisphenol A type epoxy resin (epoxy equivalent: 171) was used as a bifunctional epoxy resin, and tetrabromobisphenol A (hydroxyl equivalent: 272) was used as a halogenated difunctional phenol. The phenolic hydroxyl group was blended so as to be 1 / 1.006, lithium hydroxide was used as a catalyst in the presence of 0.065 mol with respect to 1 mol of the epoxy resin, and N, N-dimethylacetamide was used as a solvent. Solid content concentration is 30% by weight
Is adjusted so that the viscosity is 3500 mPa
· Gel permeation chromatography (GP) having a film-forming ability obtained by heating and polymerizing in the solvent.
The weight average molecular weight in terms of styrene by the method C) is 285,0
00 high molecular weight epoxy polymer, the reduced viscosity of which is:
1.17d at 30 ° C in N, N-dimethylacetamide
1 / g. Isophorone diisocyanate is used as an isocyanate having two or more isocyanate groups in the high molecular weight epoxy polymer, and 1.0 equivalent of methyl ethyl ketone oxime is used as a masking agent for 1.0 equivalent of the isocyanate group. It was blended so that 0.5 equivalent of isocyanate group was equivalent to 1 equivalent of alcoholic hydroxyl group of the epoxy polymer. 30 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 195) as a polyfunctional epoxy resin and 20 parts by weight of a phenol novolak resin (hydroxyl equivalent: 106) as a curing agent for 100 parts by weight of a high molecular weight epoxy polymer. Then, a varnish was obtained. This varnish was applied to one side of a 50 μm thick polypropylene film, and dried in a dryer.
It was dried under the conditions of 100 ° C. and 0.5 hr to obtain a semi-cured epoxy adhesive film having a thickness of 43 μm.

(Test Method) The measurement methods in Examples and Comparative Examples, the characteristics of the adhesive film, and the storage stability of the varnish were tested by the following methods. Table 1 shows some of the test results.・ Viscosity Using an EMD type viscometer (Tokyo Keiki Co., Ltd.), 25
Measured in ° C. -Styrene-equivalent weight average molecular weight by gel permeation chromatography (GPC) method The column used for gel permeation chromatography (GPC) is TSKgel G6000 + G5000 + G400.
0 + G3000 + G2000. The eluent contains N,
The sample concentration was 2% by weight using N-dimethylacetamide. After determining the relationship between the molecular weight and the elution time using styrenes having different molecular weights, the elution time of the sample was measured, the molecular weight was estimated, and the result was defined as the weight average molecular weight in terms of styrene. -Reduced viscosity The high molecular weight epoxy polymer was measured using an Ubbelohde viscometer. -Tensile strength and elongation Tensile strength and elongation were measured using a film manufactured by Toyo Baldwin Co., Ltd.
10 mm, and the pulling speed was 5 mm / min. -Adhesive strength TSA-18 (Furukawa Circuit Foil Co., Ltd., a semi-cured epoxy adhesive film and 18 μm copper foil,
(Trade name), and heated and pressurized under the conditions of 170 ° C., 2 MPa, and 30 minutes, and laminated and integrated.
The film was pulled in the ° direction and the peel strength was measured. -Tg As the glass transition point (Tg), a differential scanning calorimeter 910 (trade name, manufactured by DuPont) was used.・ Chemical resistance The cured sample film is treated with methyl ethyl ketone, N, N
-Dipped in each of dimethylacetamide, toluene, acetone, methylene chloride, 10% hydrochloric acid, and 10% sodium hydroxide for 30 minutes, the surface was visually observed, and those without swelling and dissolution were judged to be good. -Storage stability of varnish The varnish was allowed to stand at room temperature for 7 days, stirred, visually observed, and those not gelled were judged to be good.

[0050]

[Table 1]

[0051]

As described above, according to the present invention, it is possible to provide a method for producing an adhesive film having excellent strength and adhesiveness, and excellent in heat resistance and chemical resistance.

Claims (13)

[Claims] 1. A halogenated bifunctional epoxy resin and a halogenated bifunctional phenol are blended so that epoxy group / phenol hydroxyl group = 1 / 0.9 to 1 / 1.1, and in the presence of a catalyst, Gel permeation chromatography (GPC) with film-forming ability obtained by heating and polymerizing in a solvent
A mask isocyanate obtained by masking (blocking) an isocyanate group of an isocyanate having two or more isocyanates on a high molecular weight epoxy polymer having a weight average molecular weight in terms of styrene of 50,000 or more by a method, and a polyfunctional epoxy resin; A method for producing an epoxy adhesive film, comprising mixing a curing agent, applying the curing agent to one or both surfaces of a support film, and removing the solvent by drying. 2. The method for producing an epoxy adhesive film according to claim 1, wherein the weight average molecular weight in terms of styrene of the high molecular weight epoxy polymer is 100,000 or more as determined by gel permeation chromatography (GPC). . 3. The method for producing an epoxy adhesive film according to claim 1, wherein the polymerization reaction solvent is an amide solvent. 4. The reduced viscosity of the high molecular weight epoxy polymer is as follows:
It is 0.50 dl / g or more, The Claims 1-3 characterized by the above-mentioned.
The method for producing an epoxy adhesive film according to any one of the above. 5. The reduced viscosity of the high molecular weight epoxy polymer is as follows:
5. It is 0.80 dl / g or more.
The method for producing an epoxy adhesive film according to any one of the above. 6. The method for producing an epoxy adhesive film according to claim 1, wherein the halogenated bifunctional epoxy resin is a brominated bisphenol A type epoxy resin. 7. The method according to claim 1, wherein the halogenated bifunctional phenol is brominated bisphenol A.
The method for producing an epoxy adhesive film according to any one of the above. 8. The method for producing an epoxy adhesive film according to claim 1, wherein the mask isocyanate is obtained by masking (blocking) an isocyanate group with an alcohol. 9. The method for producing an epoxy adhesive film according to claim 1, wherein the mask isocyanates are obtained by masking (blocking) isocyanate groups with amines. 10. The method for producing an epoxy adhesive film according to claim 1, wherein the mask isocyanate is obtained by masking (blocking) an isocyanate group with a phenol. 11. The method for producing an epoxy adhesive film according to claim 1, wherein the mask isocyanate is obtained by masking (blocking) an isocyanate group with a ketone oxime. 12. The method for producing an epoxy adhesive film according to claim 1, wherein an isocyanate dissolved in acetylacetone is heated in place of the mask isocyanate. 13. The method according to claim 1, wherein the support film is a copper foil, and the coated surface is only a roughened surface of the copper foil.
The method for producing an epoxy adhesive film according to any one of the above.