JPS60118781A - Adhesive composition for flexible printed circuit board - Google Patents

Abstract

PURPOSE:The titled solventless composition, consisting of a specific aqueous solution of a copolymer and a water soluble water-soluble epoxy compound and an emulsion of a specific solid epoxy compound, and having improved soldering heat resistance, etc. CONSTITUTION:A compoisition obtained by incorporating (A) an aqueous solution of a copolymer of (i) 90-98pts.wt. monomer group consisting of acrylonitrile, acrylic acid esters and if necessary styrene, (ii) 1-8pts.wt. acrylic acid and/or methacrylic acid and (iii) 1-9pts.wt. hydroxyalkyl acrylates and/or acrylamides with (B) a water-soluble epoxy compound having two or epoxy groups and (C) an emulsion of a solid epoxy compound having two or more epoxy groups. USE:Bonding heat-resistant resin films, etc. to electrically conductive metallic foils and the above-mentioned metal clad laminates to cover sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive composition suitable for use in flexible printed circuit boards. A coverlay consisting of a metal foil-clad laminate, a heat-resistant resin film, or a heat-resistant resin non-woven sheet, an adhesive, and a protective sheet that has 11 mold properties. This invention relates to an improved aqueous acrylic adhesive for use in forming sheets and the like.

BACKGROUND ART In recent years, electronic devices have become smaller, lighter, and more dense, and demands for their performance are becoming increasingly sophisticated. As one of the countermeasures against this problem, flexible circuit boards, which enable electronic devices to be made smaller, lighter in weight, and higher in density, have become rapidly popular.

Flexible printed circuit boards basically use a film of heat-resistant resin such as polyester resin, polyimide resin, polyamideimide resin, or polyparabanic acid resin as a base material, or a nonwoven sheet made of fibers of these resins. A conductive metal foil such as copper or aluminum is laminated thereon via an adhesive to provide a metal foil-covered laminate.

In addition, Cover Lacey 1 is used in the final stage of the printed wiring processing process for the metal foil-clad laminate, and is used to oxidize the formed metal conductor wiring after the wiring pattern is formed by etching, etc. It is laminated and bonded onto a flexible substrate for the purpose of preventing deterioration caused by such factors. This coverlay sheet is made by applying an adhesive to a heat-resistant resin film or non-woven sheet similar to that used as the base material for metal foil laminates, semi-curing, and then applying a polyolefin film or a releasable adhesive. It is provided with a protective sheet such as paper that has been applied.

The adhesive for flexible metal foil-clad laminates and cover lay sheets (hereinafter collectively referred to as flexible substrates unless special distinction is required) has properties such as electrical strength, heat resistance, flexibility, and electrical properties. Properties such as insulation are required, and coverlay sheets are also required to have various properties such as resin flow during lamination processing, so-called wiring part embedding ability, and shelf life in a semi-cured state.

Traditionally, adhesives that meet these requirements include acrylonitrile-butadiene rubber, butyral resin, and
Crosslinkable acrylic rubber system, nylon/epoxy system, acrylonitrile-butadiene/phenol resin system, carboxy-containing acrylonitrile-butadiene/epoxy resin system,
Various adhesives such as acrylic rubber/epoxy adhesives have been proposed, and among these adhesives, acrylonitrile-
Butadiene/phenol resin type resins are widely used. Recently, acrylic rubber/epoxy adhesives have been attracting attention as they have been recognized for their excellent properties such as good electrical insulation, embeddability when used in coverlay sheets, and long shelf life. It became so.

However, since all of these adhesives are supplied as a solution of flammable organic solvents such as methyl ethyl ketone, toluene, acetone, and ethanolate, they are difficult to bond with heat-resistant substrates and metal foils in the production of flexible circuit boards, and to provide heat resistance. During processes such as applying and semi-curing adhesives to sex profiteers, it is necessary to evaporate and remove these organic solvents, which is highly dangerous and poses health risks for workers. Therefore, it was pointed out that this work required special consideration in terms of safety and occupational health.

From this perspective, emulsion polymerization type adhesives were finally developed, and their typical characteristics include adhesive strength, heat resistance,
An emulsion polymerization type acrylic rubber/epoxy adhesive with excellent basic performance such as flexibility, electrical properties characteristic of acrylic, embeddability and shelf life when used in coverlay sheets has been provided. .

However, this emulsion polymerization type adhesive has poor solder heat resistance, and this is due to the hygroscopicity of this adhesive. Therefore, it is necessary to appropriately insert a drying process into the printed circuit processing process of the flexible board, and in particular, a sufficient drying process is essential before parts are removed from the flexible board by soldering. For this reason, the number of work steps is forced to increase, and as a result, productivity and efficiency are reduced in terms of work efficiency, so these adhesives are generally not used at present. .

In order to solve this problem, the present invention Nagisa et al.
In No. 11-58-1.26917, it is a non-storage type adhesive and has excellent properties as an adhesive for flexible substrates such as adhesive strength, heat resistance, flexibility, and electrical insulation, and furthermore, it is suitable for drying process. A connector for a flexible circuit board that can simplify manufacturing of a flexible circuit board by eliminating the need for insertion (work 71).

The following was proposed as a drug combination paraboloid.

i.e. lumo/ma m'(
A) (7) 90-98 M parts, 1-8 parts by weight of acrylic acid and/or methacrylic acid (B) and 1-9 parts by weight of hydroxyalkyl acrylates and/or acrylamides (C) Copolymer (D) consisting of
A water-soluble epoxy compound (F,) having two or more epoxy groups in the molecule is added to the aqueous copolymer solution of the copolymer (F).
D) An adhesive composition for a flexible printed circuit board, characterized in that it is blended in a ratio of 20 to 60 parts by weight per 100 M parts.

This adhesive composition is extremely useful industrially and is suitably used in the industry, but under certain conditions of use, it has the disadvantage of being sticky before curing, and it is difficult to improve it. There were times when I was disappointed. In other words, when this adhesive is used for a coverlay sheet, if there is a lot of adhesive remaining, the operator may stack the coverlay sheet on a separately formed circuit board and press-form it for final curing. If the circuit board and cover lay sheet are stacked or misaligned during the process,
In order to make it difficult to peel off the coverlay sheet for correction work, it was sought to improve the degree of stickiness of the coverlay sheet to a mild or non-stick state.

The present invention was made in order to improve these problems, and is a non-solvent type and has excellent properties as a adhesive for flexible substrates such as adhesive strength, heat resistance, flexibility, and electrical insulation. Furthermore, it is an adhesive for flexible substrates that maintains its excellent features such as no drying process required during processing, while reducing the stickiness to a level that poses no practical problems when used as a coverlay sheet. The purpose is to provide a composition.

The adhesive composition for flexible printed circuit boards of the present invention comprises 90% of the monomer group (A) consisting of acrylonitrile, acrylic esters and optionally added styrene.
-98 parts by weight, 1-8 parts by weight of acrylic acid and/or methacrylic acid (13) and hydroxyalkyl acrylates and/or acrylic heptamides (C
) to an aqueous copolymerization solution of copolymer (I) consisting of 1-9fi parts of - a water-soluble epoxy compound (E) having two or more epoxy groups in the molecule and - two or more epoxy groups in the molecule. An emulsion of a solid epoxy compound having epoxy groups (1”
).

Acrylonitrile, acrylic esters, and optionally styrene are used in the monomer group (A) of the adhesive composition of the present invention.

By using acrylonitrile as a component of the monomer group (A), resistance to organic chemicals used for processing printed circuits of flexible substrates and adhesive strength (=J and for that purpose preferably 4
It is used in the range of 0-60 heavy I and L sections depending on the need for trade.

A part of this nitrile component may be replaced with styrene, if desired, in order to impart further rigidity to the skeleton of the copolymer (I), which mainly functions as an adhesive. preferably 70% of acrylonitrile
It is used in place of:

These acrylonitrile and styrene components mainly act as components that give rigidity to the adhesive, in contrast to the flexible properties of the acrylic esters, which are other components that constitute the main components of the copolymer (D). can be changed as desired to adjust properties such as the glass transition temperature of the entire adhesive composition.

As the acrylic esters which are other components of the monomer group (A) of the present invention, it is possible to use general acrylic esters of 1 diameter or more such as ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. can. This acrylic ester is a component that mainly provides adhesive strength to the adhesive and also provides flexibility, which is one of the other important performance requirements. This acrylic ester f
It is preferable to use ffi in a range of 40-80 parts by weight.

These monomer group (A) constitutes the main component of the adhesive,
The compositions can be appropriately combined within the above-mentioned preferred ranges, but according to the extensive implementation of the present invention by Nagisa et al., the entire adhesive composition including the monomer components (13) and (C) described below A glass transition point that can meet the above-mentioned performance requirements such as flexibility and chemical resistance.
It is desirable to select the temperature within the range of 0° to 0°C, and the monomer group (A) as a whole copolymer (■))
The composition for is selected from the range of 90-98 parts by weight.

Acrylic acid and/or methacrylic acid (13) as a component of the copolymer (I) component of the adhesive composition of the present invention
These components are added in appropriate amounts in order to adjust the crosslinking density of the entire adhesive composition, and the amount is determined based on the copolymer (I).
)), selected from the range of 1-8 heavy traps.

If the amount of acrylic acid and/or methacrylic acid is less than 614 parts per weight, the aqueous copolymerization solution will be stable and advantageous.

Furthermore, even if an aqueous copolymer solution is obtained and used as an adhesive, a flexible substrate that is satisfactory in terms of peel strength after heat resistance, chemical resistance, etc. cannot be obtained. On the other hand, if the amount exceeds 8 parts by weight, crosslinking will proceed too much and three-dimensionality will become excessive, resulting in a significant decrease in the bending strength of the flexible substrate σ), and furthermore, a decrease in peel strength after heat resistance. It is permitted to do so.

It is assumed that the crosslinking reaction mentioned here occurs between the carboxyl group of acrylic acid or methacrylic acid and the epoxy group of the uboxy resin (described later).

Next, in the present invention, hydroxyalkyl acrylics are used because these monomers are hydrophilic monomers, and together with monomer groups (A) and (3) in the present invention, these components stably coexist in water. This is because it becomes an essential component for polymerization. Examples of the hydroxyalkyl acrylic esters include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate-1.
-Hydroxyalkyl acrylic-1, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 3-hydroxyethyl acrylate, etc. can be used, and these can be used alone or in combination of two or more. can.

Various acrylamides can be used, such as acrylamide, methacrylamide, and N-methylol acrylamide, and one or more of these may be used.

These hydrophilic monomers include hydroxyalkyl acrylic acid esters and acrylamide; each may be used alone or both may be used in combination, but the amount thereof is 1. -9
Selected from a range of parts by weight. If this 111 is less than 1 weight part, the hydrophilization of the monomer in the aqueous polymerization system will be insufficient, and a stable monomer fraction state during the combination operation will not be ensured, and in such a state, it will not be possible to When polymerized, the composition of the copolymer becomes non-uniform and the dispersion of the copolymer in the polymerization solution becomes unstable, making it impractical as an adhesive for flexible substrates. On the other hand, if the amount of this hydrophilic monomer exceeds the 9-ply plate portion, the originally excellent properties of the composition of the present invention such as adhesiveness, heat resistance, and flexibility will be impaired, and especially in soldering. There is a significant decrease in heat resistance.

Copolymer (D) of the present invention comprising the above monomer group
The aqueous copolymerization solution can be produced by the following method. That is, a predetermined amount of potassium persulfate as a polymerization initiator is dissolved in distilled water at 70°C,
A mixture of separately prepared monomer groups (A), (I3), and (C) of the present invention and distilled water is dropwise polymerized while stirring for about 3 to 4 hours, and the polymerization is completed over a further 4 hours. After that, it is cooled to room temperature, and after passing through a suitable P material to remove excessive particles, the particle size is adjusted to 7-9 using ammonia water or the like.

At this time, the resin component (1) in the aqueous copolymerization solution is adjusted to 30 to 70 parts by weight of the entire reaction system, that is, within a range where the copolymerization reaction can be carried out well, and the resin component (1) The adhesive composition liquid of the present invention can be obtained by dissolving the epoxy resin.

In addition, in the copolymerization operation of the polymer, a chain transfer agent or the like may be added according to a conventional method, or a dispersant may be added as long as it does not impair the properties of the resulting adhesive composition for use in flexible substrates. It can also be used supplementarily depending on the situation.

Another component of the adhesive composition of the present invention is a water-soluble epoxy compound having two or more epoxy groups in one molecule (E
) and - an emulsion (1) of a solid epoxy compound having two or more epoxy groups in the molecule. Examples of the water-soluble epoxy compound (1) include ethylene glycol diglycidyl ether, main Gepoxy compounds that have a hydrophilic ether bond in the main chain of molecules such as polyethylene glycol diglycidyl ether with a chain carbon number of 9 or less; One or more types of polyepoxy compounds having alcoholic hydroxyl groups as well as ether bonds are used.

In addition, emulsions (F') of solid epoxy compounds include emulsions of novolac type epoxy, emulsions of cresol type epoxy, emulsions of bisphenol doll epoxy, emulsions of bisphenol F type epoxy, etc., which have a phenol skeleton in the molecule. One or more types of emulsions such as epoxy compounds of polyhydric phenols are used.

This water-soluble epoxy compound (E) not only reinforces the adhesive strength of the adhesive, but also partially reacts with the carboxyl groups contained in the copolymer (1) to form a frame structure, and It is a component that provides rigidity and heat resistance.

In addition, the emulsion of the solid epoxy compound (1=') not only reinforces the adhesive strength of the adhesive similarly to the water-soluble epoxy compound, but also partially reacts with the carboxyl group contained in the copolymer (D). It is a component that forms a crosslinked structure and provides rigidity and heat resistance to the adhesive.

The mixing ratio of the water-soluble epoxy compound (E) and the solid epoxy compound emulsion (F) may be adjusted appropriately depending on the required degree of adhesion of the adhesive surface.The preferred range is as follows:
The amount of the total epoxy compound including the solid content of the water-soluble epoxy compound (E) and the solid epoxy compound emulsion (F) is 20 to 6 parts by weight based on 100 parts by weight of the copolymer (1)).
This is the range of 0-layer seams. If the amount is less than this range, it will be difficult to obtain sufficient heat resistance and chemical resistance in the adhesive composition, and if it exceeds this range, there will be a tendency for not only the chemical resistance to decrease but also the bending durability to be insufficient. .

Emulsion of solid epoxy compound within the above range (1
It is preferable that the solid content of ``) is in the range of 10 to 50% by weight based on the total amount of the epoxy compound.

When the amount is less than this range, the tackiness is relatively high, and when it exceeds this range, the peel strength after heat resistance tends to decrease.

The adhesive composition of the present invention obtained as described above is generally an aqueous adhesive having a molecular weight of 7-9 and a viscosity of 100 to 4000 centipoise. This adhesive is applied onto a heat-resistant resin film or non-woven sheet to a film thickness of 0 to 80μ (dry base), and then dried and cured to form the desired flexible substrate. I (I Ru.

The conditions for drying and curing the adhesive are as follows: First, for the coverlay sheet, for example, hot air at a temperature of 80° C. to 180° C. is used, and a residence time of 0.5 minutes to 20 minutes is given for drying and semi-curing; A releasable polyolefin film or release paper is pasted on the surface of the semi-cured l-resin to produce a product.

This coverlay sheet is laminated on the board on which wiring has been formed at the user's side, and then the i! llt degree is 16 (1”C
l, 'l: 180℃, pressure 10Kg/crI to 60K! /t,Ill.

By hot pressing for 30 to 90 minutes, the adhesive is completely cured and the bonding between the wiring board and the coverlay sheet is completed.

On the other hand, in the production of metal foil-clad laminates, after obtaining a semi-cured state of the adhesive similar to the case of the coverlay sheet described in "-", rolled copper foil with a thickness of 5 μm to 80 μm, After laminating electrolytic copper foil, rolled aluminum foil, etc.,
Apply a linear pressure of 3-50' with a heat-resistant rubber roll or cotton roll in contact with a metal roll heated to ℃ to 150℃.
Arrived monthly with 8 2/α fish and laminated and hardened. Thereafter, a post cure is usually performed for 3 to 48 hours in an atmosphere of 80° C. to 200° C. to completely cure the material, thereby obtaining a metal foil-clad laminate.

However, the usage conditions shown here are just examples, and it is natural that the manufacturing conditions will vary depending on the coating machine used, the structure and specifications of the pressing roll, etc., and the optimal conditions should be determined at the time of manufacturing. In any case, as long as the adhesive of the present invention is used, organic solvents will not volatilize in the above manufacturing process unlike in the case of solvent-based adhesives, and manufacturing workers will not be exposed to the risk of inhalation of volatilized solvents or fire hazards. be freed from

In addition, printed circuit boards using the adhesive of the present invention have improved soldering heat resistance, and soldering, which was essential for printed circuit boards using conventional emulsion-polymerized acrylic adhesives, is done in the previous drying process. The adhesive of the present invention provides extremely useful effects industrially, such as making it possible to omit the process.

Add supplementary explanations while showing examples below.

The characteristics of the printed circuit boards shown in Examples and Comparative Examples were evaluated according to the following method.

1. Peel strength 11) The adhesion strength between the copper foil and the base-to-thermal film was measured based on C-II" C-24013. In the examples of the present invention, the copper conductor wiring on which the printed circuit was formed The adhesion strength between the surface and the coverlay sheet is shown.Normal state refers to the test after being left at a temperature of 20℃ and relative temperature of 65% for 48 hours, and after heat resistance refers to the test after being left at 20℃ for 24 hours. means.

2. Solder heat resistance The wiring surface (coverlay sheet laminated side) was brought into contact with solder and floated in a solder bath at 260° C. for 60 seconds, and then the appearance was observed. Here, "after water immersion" refers to water resistance and moisture resistance. After immersing the circuit board in water for one hour at room temperature, take it out, wipe off the water with a cloth, and then do the soldering process as described above. It was floated in the bath and its appearance was observed.

3. Chemical resistance In accordance with JISC6481, the test piece was soaked in trichlene, acetone, and methylene chloride for 15 minutes at room temperature for 7N.
After taking it out, the appearance was observed.

4.4 Folding strength Using an MIT type repeated bending tester, test piece 500I
The number of times the conductor was bent under a load was measured until the conductor stopped conducting.

5. Insulation resistance according to JISC6481, normal condition (7!1; '1 degree 20
"C5 relative humidity 65%<> a n6; number of intervals 11v1
After that, the volume solid resistance was measured.

Example 1 1 part of acrylonitrile 30M, 10 ethyl acrylate
Parts by weight, 1.50 parts by weight of butyl acrylate, 5M11 parts of methacrylic acid, and 5 parts of hydroxyethyl acrylate
A portion of M was also mixed with distilled water to prepare a monomer group mixture.

Next, a predetermined amount of potassium persulfate as a polymerization initiator was added at 70%
3. Prepare an aqueous solution dissolved in distilled water at ℃, and add the previously prepared monomer group mixture to this aqueous solution while stirring.
The mixture was added dropwise over a period of 5 hours, and after the completion of the dropwise addition, polymerization was continued for an additional 45 hours to complete the reaction. Then, cool the reaction solution to room temperature and
After removing excessive particles by filtration, the aqueous copolymerization solution containing 50% by weight of the resin component was prepared as 11). The resulting aqueous copolymerization solution has a pH of
is 7.6, the viscosity is 1050 centipoise, and the glass transition point of the resin component was separately measured by DSC method.
It was ℃. The co-1-1\ polymer (1
)) To 100 parts by weight, 20 parts by weight of diethylene glycol glycidyl ether (trade name: Tenacol EX-853, manufactured by Nagase Sangyo Co., Ltd.) was mixed and dissolved in an aqueous copolymerization solution, and further, an emulsion of bisphenol A-type epoxy was prepared. (Product name: Evolution l, A-;3 +NV-50
%, manufactured by Kanebo NSC Co., Ltd.) were mixed and dissolved to obtain a filler composition of the present invention. This adhesive composition liquid was applied to a polyimide film (E.I. DuPont's product: trade name, Kapton) with a thickness of about 25μ (dry base) using reverse coke, dried, and semi-cured ( Temperature 120℃, residence time 5 minutes)
After that, an electrolytic copper foil (manufactured by Fukuda Kinh4 Co., Ltd.: product name T-7) with a thickness of 35 μm was laminated, and a line pressure of 5 to 9/CnL was applied to the roll.
Pressed at u'1 degree and 140℃, then 160℃,
A flexible copper-clad laminate was obtained by post-curing for 2 hours.

Furthermore, the adhesive composition of the present invention obtained in this example was applied to a polyimide film (E.I. DuPont Co., Ltd. product: trade name, Kapton) with a thickness of about 50 μm (dry base) by reverse roll coke. Apply to a thickness of , dry, and semi-cure (+?1
A polyester film having a thickness of 25/L was laminated thereon to produce Cover Lacey 1.

This Tsunoburley sheet has less sticky adhesive and is very easy to handle. Using this and the previously produced flexible copper-clad laminate, printed circuit processing of a test pattern was carried out using the Zabtract method to produce a flexible printed circuit board. The characteristics of this circuit board were evaluated for each of the above items.

The press conditions for Naori Barley Sea 1 are press pressure 3o.
K9/y, temperature 160°C, and press time 30 minutes.

The results of the α chain showed that the adhesiveness was very low (peel strength was 1.5 to 9/Cm under normal conditions, and 1. to 9/Cm even after heat resistance). The film remained in good condition, and no abnormalities were observed even after immersion in the chemical. [Resistance] J〒Tested 130 times on average, insulation resistance is 1-0"Q and A').

Example 2 Acrylonitrile 1.5 weight, ti't MI, styrene 15 parts by weight, butyl acrylate) 60 m tf
i part, 5 m of meth-1'acrylic acid, 1 part, 1.8 parts by weight of hydroxyethyl acrylate, and 2 tn of acrylamide.
11 parts were mixed in distilled water and subjected to IR according to the method of Example 1.
An aqueous copolymerization solution containing 60% by weight of the U1 resin component was prepared (IJ).

This aqueous copolymer solution has a pJI of 78, a viscosity of 12 centiboise, and the glass transition point of the resin component is DS.
When measured by O method, -i 501j -C' was found.

Copolymer (1)) 1 in this solution is added to this aqueous copolymer solution.
00 parts by weight, sorbitol tetragrindyl ether (manufactured by Nagase Sangyo Co., Ltd.: trade name Denacol EX-6)
11) were mixed and dissolved, and then an orthocresol novolanok type epoxy resin emulsion (manufactured by Nagase Sangyo Co., Ltd., commercial name: Bunacol EM 125 N) was added.
The adhesive composition liquid of the present invention was obtained by mixing and dissolving 4.(] Nail Prize (V = 25%).

This adhesive composition liquid was applied to a polyamide-imide film (a film made of a polymer obtained by the method of Japanese Patent Publication No. 56-1/4/891-1, etc.) with a thickness of 50μ. - (Apply to a thickness of 1μ (dry base) and dry at 14.0°C 17 (i) for 2 minutes for a residence time of 2 minutes. After curing, a thickness of 30
μ rolled copper >i'1 (manufactured by If Co., Ltd.: trade name,
N-02) 1 layer, linear pressure], Q Leg
/ Cjll % Roll 1'f11: degree 110°C
Press under the following conditions, then post-cure at 1300C for 16 hours to form a 7 legible copper clad laminate. Uta.

What about the example? ! The adhesive composition solution of the present invention prepared by J was coated onto a polyamide-imide film similar to that used for the copper-clad laminate described above to a thickness of 70 μm (dry base) using a reverse roll coater. After drying and semi-curing at a temperature of 130°C and a residence time of 7 minutes, a release paper (manufactured by Fujimori [-1 Industry Co., Ltd.: trade name, Baina Sheet) was added to obtain Cover Lacey 1. .

Using this coverlay sheet and the previously produced flexible copper-clad laminate, printed circuit processing was carried out using a Zabtract test pattern to obtain a flexible printed circuit board. 'I!' of this circuit board! +'('1 was evaluated for each item above.

Note that the press conditions for the coverlay sheet are a press pressure of 50'/=. ．． Spirit, degree 1. The temperature was 70°C and the pressing time was 40 minutes. The evaluation results are the peel strength J. G'9
/ (, 711, even after heat resistance],, O Kg/crn, solder 1 heat control was normal, good even after water immersion, no particular abnormality was observed after chemical immersion. Folding strength was also 1 on average.
50 times, the insulation resistance was 10 Ω.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (4)

[Claims] (1) Monomer group consisting of acrylonitrile, acrylic esters, and optionally added styrene (
90-98 parts of A), -8 parts by weight of acrylic acid and/or methacrylic acid CB) and 1-9 parts by weight of hydroxyalkyl acrylates and/or acrylamides (C) copolymer (
1) Water-soluble epoxy compounds having two or more epoxy groups in the molecule (1 and 1 minute) were added to the aqueous copolymerization solution of 1)).
An adhesive silk composition for a flexible printed circuit board, characterized in that it contains an emulsion (1'') of a solid epoxy compound having two or more epoxy groups in r-. (2) The adhesive composition according to claim 1, wherein the monomer group (A) comprises acrylonitrile, styrene, and acrylic esters. (3) The adhesive composition according to claim 1, wherein the monomer group (A) consists of acrylonitrile and acrylic esters. (4) The solid content ratio of the water-soluble epoxy compound (E) and the solid epoxy compound emulsion (F) is the same as that of (E) and (F) with respect to 100 parts by weight of the copolymer (D). Adhesive X, No. 11 composition according to claim 1, which has a total content of 20 to 60 parts by weight.