JP2003176470A - Flame retardant adhesive composition for flexible printed wiring board and flexible printed wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flame retardant adhesive composition for a printed wiring board free from halogen, manifesting high fire retardancy and excellent in slide bending resistance and adhesive properties, and to provide a flexible printed wiring board using the same. <P>SOLUTION: The flame retardant adhesive composition for the flexible printed wiring board contains following components (A)-(D) as the indispensable components, and the flexible printed wiring board is obtained from this composition; (A) a thermoplastic resin; (B) a phenoxy resin containing phosphorus; (C) an epoxy resin containing phosphorus; (D) a curing agent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant adhesive composition for a flexible printed wiring board which is non-halogen and excellent in flame retardancy, and a flexible printed wiring board using the same.

[0002]

2. Description of the Related Art In recent years, the demand for flexible printed wiring boards has increased with the diversification of electronic devices such as miniaturization and high density. Along with this, flexible printed wiring boards are required to have the ability to withstand repeated sliding and bending.
In consumer equipment, there is a strong demand for flame retardancy, especially from the standpoint of safety, and in addition to the sliding flexibility described above,
There is a demand for a flexible printed wiring board that is also satisfactory in terms of flame retardancy.

The flexible printed wiring board is, for example,
Stick the copper foil on the polyimide resin film (base material),
After forming a circuit on the copper foil surface by etching or the like, a cover lay film is attached so as to cover the copper foil surface. The cover lay film is one in which an adhesive layer is formed on one surface of a resin film made of a polyimide resin or the like. Also, an adhesive is appropriately used for sticking the base material and the copper foil.

As described above, the adhesive used in such a flexible printed wiring board is also required to have high flame retardancy. Specifically, the VTM-in the UL-94 standard is required. High flame retardancy of 0 class is required. In order to satisfy such high flame retardancy, conventionally, flame retardants such as halogen compounds and antimony compounds have been contained in the adhesive composition, but in recent years, interest in environmental problems has increased. However, halogen compounds are a factor in generating harmful substances such as dioxins during combustion, and antimony compounds have been pointed out to be carcinogenic.Therefore, flame-retardant adhesives that do not use these compounds are required. ing. Under such circumstances, for example, 9, 10
-Dihydro-9-oxa-10-phenanthrene-10
A technique has been proposed in which an epoxy resin derived from oxide is used to achieve flame retardancy without containing halogen or the like (Japanese Patent Laid-Open Nos. 2000-212538 and 200).
0-256537, JP 2000-336253 A, etc.).

[0005]

However, in the above proposal, the adhesiveness to the polyimide resin film cannot be sufficiently obtained, and the adhesive strength is higher than that in the case where the conventional adhesive containing a halogen-based flame retardant is used. It was clearly inferior, and as a result, delamination was likely to occur, which was a drawback.
Further, what has sufficient adhesiveness to a polyimide resin film and can sufficiently meet the above-mentioned requirements (flame retardancy, sliding flexibility and non-halogenation) has not yet been obtained. The current situation is not.

The present invention has been made in view of the above circumstances and is a halogen-free flame-retardant adhesive for flexible printed wiring boards which is highly flame-retardant and is also excellent in sliding flexibility and adhesiveness. An object of the present invention is to provide an agent composition and a flexible printed wiring board using the same.

[0007]

In order to achieve the above object, the present invention provides a flame-retardant adhesive composition for flexible printed wiring boards, which comprises the following (A) to (D) as essential components. The second gist is a flexible printed wiring board using the flame-retardant adhesive composition for a flexible printed wiring board. (A) Thermoplastic resin. (B) Phosphorus-containing phenoxy resin. (C) Phosphorus-containing epoxy resin. (D) Curing agent.

That is, the inventors of the present invention have conducted a series of researches to solve the above-mentioned problems, and as a result, by using the above-mentioned respective components as essential components in an adhesive composition for a flexible printed wiring board, flame retardancy and sliding property are improved. The present inventors have found that not only dynamic bendability but also a satisfactory level of adhesion to a substrate or the like can be obtained, and the present invention has been accomplished.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The flame-retardant adhesive composition for flexible printed wiring boards of the present invention (hereinafter simply referred to as "adhesive composition")
Is a thermoplastic resin (A component), a phosphorus-containing phenoxy resin (B component), a phosphorus-containing epoxy resin (C component),
It can be obtained using a curing agent (component D).

The thermoplastic resin (component A) is not particularly limited, and examples thereof include polyamide resin, polyester resin, polycarbonate resin, polyphenylene oxide resin, polyurethane resin, polyacetal resin, polyethylene resin and polypropylene resin. Resins, polyvinyl resins, etc. may be mentioned alone or in combination.
Used in combination with more than one species. Among them, a polyamide resin is preferably used because of its adhesiveness to a polyimide resin film, and an alcohol-soluble polyamide resin which is solid at room temperature is more preferable.

Here, the above-mentioned "alcohol-soluble polyamide resin which is solid at room temperature" is a polyamide resin which is soluble in an alcohol solvent and is a copolymerized polyamide resin obtained by copolymerizing dibasic acid or diamine. Or a polyamide resin having an N-alkoxymethyl group introduced into a polyamide bond in the molecule.

The above copolymerized polyamide resin can be obtained by using two or more kinds of dibasic acids and two or more kinds of diamines as monomers. Specific examples of the dibasic acid include adipic acid, sebacic acid, azelaic acid, undecanoic acid, dodecanedioic acid, dimer acid, isophthalic acid, terephthalic acid and sodium 5-sulfoisophthalate. Moreover, as said diamine, specifically, hexamethylene diamine, heptamethylene diamine, p-
Examples thereof include diaminomethylcyclohexane, bis (p-aminocyclohexyl) methane, m-xylenediamine, piperazine and isophoronediamine. Then, the copolymerized polyamide resin, particularly when it is obtained by copolymerizing an aliphatic dibasic acid and an alicyclic diamine, excellent solubility in a solvent, viscosity even after long-term storage Is hardly increased, and good adhesion to a wide range of adherends is exhibited, which is preferable.

Further, the above-mentioned copolymerized polyamide resin may be appropriately blended with an aminocarboxylic acid or the like at the time of its preparation.
Specifically, 11-aminoundecanoic acid, 12-aminododecanoic acid, 4-aminomethylbenzoic acid, 4-aminomethylcyclohexanecarboxylic acid, ε-caprolactam, ω-laurolactam, α-pyrrolidone, α-piperidone, etc. Lactam, etc.

The copolyamide resin thus obtained is, for example, 6/66, 6 / 6-10, 6/66 /
6-10, 6/66/11, 6/66/12, 6 / 6-
10 / 6-11, 6/11 / Isophorone diamine, 6 /
It has a configuration of 66/6, 6 / 6-10 / 12 and the like.

The above-mentioned polyamide resin having an N-alkoxymethyl group introduced into the polyamide bond in the molecule is an alcohol-soluble polyamide resin obtained by adding formaldehyde and alcohol to the polyamide bond and introducing an N-alkoxymethyl group. It is what Specific examples thereof include those obtained by alkoxymethylating 6-nylon, 6,6-nylon and the like. Then, the introduction of the N-alkoxymethyl group contributes to a decrease in melting point, an increase in flexibility, and an improvement in solubility, and depending on the purpose,
The introduction rate is set appropriately.

The melting point of the thermoplastic resin (component A) of the present invention comprising such a resin is preferably in the range of 50 to 220 ° C, more preferably 70 to 180 ° C. That is, if the melting point is less than 50 ° C, the cured adhesive will be inferior in heat resistance, and conversely 220 ° C.
If it exceeds, the solubility in the solvent is insufficient, which is not preferable in the present invention. Incidentally, the measurement of the melting point,
For example, by a microscopic method.

The thermoplastic resin (component A) is preferably solid at room temperature. That is, when it is liquid at room temperature, the reaction becomes too fast when blended with the epoxy compound, and gelation may occur, which may cause precipitation in the solution or significantly thickening.

The glass transition temperature of the thermoplastic resin (component A) is preferably in the range of 10 to 80 ° C, more preferably 15 to 70 ° C. That is, if the glass transition temperature is less than 10 ° C., the glass transition temperature of the cured adhesive will be low, and blocking will occur due to residual heat of the press plate during vacuum press molding, resulting in short-term adhesion. On the contrary, when the temperature exceeds 80 ° C., the cured product of the adhesive becomes too hard and becomes brittle, and sufficient adhesiveness cannot be obtained. The glass transition temperature is, for example,
It can be measured by DSC (differential scanning calorimetry).

Along with the above thermoplastic resin (component A), the phosphorus-containing phenoxy resin (component B), which is an essential component of the present invention, has a molecular skeleton mainly composed of phenoxy resin and contains a phosphorus element such as phosphorus. Phenoxy resin 1
It contains several (about 1 to 5) moles. Here, the term “main body” is intended to include a case where the entire body excluding the phosphorus element is made of a phenoxy resin. Specific examples of the phosphorus-containing phenoxy resin include ERF-001-4AF30 manufactured by Tohto Kasei Co., Ltd.

In addition to the thermoplastic resin (component A) and the phosphorus-containing phenoxy resin (component B), the phosphorus-containing epoxy resin (component C), which is an essential component of the present invention, has a molecular skeleton mainly composed of an epoxy resin. It also contains phosphorus element. The above-mentioned phosphorus-containing epoxy resin can be obtained, for example, by reacting an epoxy resin with an organic phosphorus compound. Specifically, an epoxy resin containing 20% by weight or more of a novolac type epoxy resin (a curable epoxy resin), an organic phosphorus compound having one active hydrogen bonded to a phosphorus atom, and a quinone compound It can be obtained by preparing a compound obtained by reacting with a predetermined ratio (a ratio in which the molar ratio of the quinone compound to the organic phosphorus compound is more than 0 and less than 1) and reacting them. here,
As an example of the above-mentioned "organic phosphorus compound having one active hydrogen bonded to a phosphorus atom", the following general formula (1)
And the compounds represented by the general formula (2). Then, as a specific example of the phosphorus compound represented by the general formula (1), HCA (9,10-dihydro-9-oxa-1)
0-phosphaphenanthrene-10-oxide, manufactured by Sanko Chemical Co., Ltd.). Further, a specific example of the phosphorus compound represented by the general formula (2) is diphenylphosphine oxide.

[0022]

[Chemical 1]

[0023]

[Chemical 2]

Curing agent (D component) which is an essential component of the present invention
Is not particularly limited, and examples thereof include amine-based curing agents and acid anhydride-based curing agents. As the amine curing agent, specifically, a methylated melamine resin,
Butylated melamine resin, melamine resin such as benzoguanamine resin, dicyandiamide, 4,4′-diphenyldiaminosulfone and the like can be mentioned, and these can be used alone or in combination of two or more kinds. Examples of the acid anhydride-based curing agent include aromatic acid anhydrides and aliphatic acid anhydrides, which may be used alone or in combination of two or more.

In the adhesive composition of the present invention, the proportion of each component is 50 to 500 parts by weight of phosphorus-containing phenoxy resin (component B) to 100 parts by weight of the thermoplastic resin (component A) (hereinafter abbreviated as "part"). Parts, phosphorus-containing epoxy resin (C component)
It is preferable to set in the range of 20 to 200 parts and 3 to 50 parts of the curing agent (D component), and more preferably, A
With respect to 100 parts of the component, the range is 100 to 300 parts of the B component, 30 to 150 parts of the C component, and 5 to 20 parts of the D component. That is, if it is such a content ratio, the adhesiveness to polyimide will become stronger. When the ratio of the B component to the A component is less than 50 parts,
Since the phosphorus content of the entire adhesive composition becomes low, the flame retardancy tends to be inferior, and conversely, when it exceeds 500 parts, the cured adhesive becomes inflexible and easily cracked, or the adhesive strength is reduced. This is because there are tendencies such as not being sufficient. Further, if the ratio of the C component to the A component is less than 20 parts, the crosslink density may not be sufficient, so that sufficient heat resistance and adhesive strength may not be obtained. Conversely, if it exceeds 200 parts, the cured product will be hard. This is because there is a tendency that the adhesive strength is too high to obtain sufficient adhesive strength. Furthermore, D for the above A component
If the ratio of the components is less than 3 parts, the crosslinking density tends to be insufficient and heat resistance and adhesive strength tend not to be sufficiently obtained. On the contrary, if it exceeds 50 parts, the stability of the adhesive will deteriorate. This is because there is a tendency that the gel becomes thickened over time and the pot life becomes shorter.

The adhesive composition of the present invention contains the above A
In addition to the components (D) to (D), additives such as a curing accelerator, a flame retardant, a silane coupling agent, a heat aging inhibitor, a leveling agent, a defoaming agent, and an inorganic filler can be appropriately added.

The curing accelerator is not particularly limited, and examples thereof include imidazole compounds, aromatic carboxylic acids, blocked isocyanate compounds, block sulfonic acid compounds, and the like. In particular, it is preferable to use the imidazole compound and the aromatic carboxylic acid in combination.

Specific examples of the imidazole compound include 2-methylimidazole, 2-ethyl-4-methylimidazole (2E4MZ), 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole and 1-cyanoethyl. 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6- (2-methyl-1-imidazolyl) -ethyl-1,3,5-triazine, 2, 4-
Diamino-6- (2-undecyl-1-imidazolylethyl) -1,3,5-triazine, 2,4-diamino-
Examples thereof include 6- (2-ethyl-4-methyl-1-imidazolylethyl) -1,3,5-triazine. These may be used alone or in combination of two or more.

Specific examples of the aromatic carboxylic acid include benzoic acid, 1,2-benzenedicarboxylic acid and 1,3.
-Benzenedicarboxylic acid, 1,4-benzenedicarboxylic acid, 1,2,3-benzenetricarboxylic acid, 1,2,4
-Benzenetricarboxylic acid (trimellitic acid: TM
A), 1,3,5-benzenetricarboxylic acid and the like. These may be used alone or in combination of two or more. Among these, polyfunctional benzenedicarboxylic acids and benzenetricarboxylic acids are preferably used because the degree of crosslinking of the cured product can be increased and the resistance to moist heat can be further improved.

A phosphorus compound such as triphenyl phosphate is preferably used as the flame retardant. Specific examples thereof include PX-200 manufactured by Daihachi Chemical Co., Ltd.

The phosphorus content in the adhesive composition of the present invention is preferably set to 2% by weight or more, more preferably 2.3 to 3.5% by weight. That is, by setting the phosphorus content to 2% by weight or more, it is possible to impart high flame retardancy of UL-94-VTM-0 class.

The adhesive composition of the present invention can be obtained by mixing and stirring the above-mentioned components. The adhesive composition is usually used by dissolving it in a solvent. As the solvent, those capable of dissolving the above-mentioned respective components are preferably used, and specifically, methanol, ethanol, i-propyl alcohol, n-propyl alcohol, i-butyl alcohol, n-butyl alcohol. ，
Alcohol solvents such as benzyl alcohol, ethylene glycol methyl ether, propylene glycol methyl ether, diethylene glycol monomethyl ether, diacetone alcohol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, isophorone, toluene, xylene Examples include aromatic solvents such as ethylbenzene and mesitylene, ester solvents such as methyl acetate, ethyl acetate, ethylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, and chlorine solvents such as chloroform, carbon tetrachloride, dichloromethane and trichloroethylene. To be These may be used alone or in combination of two or more.

When the adhesive composition of the present invention is used by dissolving it in a solvent as described above, the resin solid content concentration is preferably set to 3 to 80% by weight,
More preferably, it is in the range of 10 to 50% by weight. That is, when the above concentration exceeds 80% by weight, the viscosity of the solution becomes too high, which makes it difficult to uniformly coat the resin film surface, and conversely, when it is less than 3% by weight, a coating film having a desired thickness is obtained. Is difficult to form.

By the way, the flexible printed wiring board of the present invention is formed, for example, by laminating a copper foil circuit board and a coverlay film. The cover lay film has an adhesive layer formed on one surface of a resin film, and the adhesive composition of the present invention is used as the adhesive layer.

In the copper foil circuit board, a flexible film and a copper foil are bonded together by a method such as roll pressure bonding or heat pressing using an appropriate adhesive, and then a copper foil is formed so as to form a predetermined circuit pattern. The layer is etched. In addition,
As the above adhesive, the adhesive composition of the present invention may be appropriately used.

As the resin film forming the coverlay film, a film having an electric insulating property similar to that of the flexible film is used. For example, a heat resistant film made of polyimide, polyester, polyether ketone, polyphenylene sulfide, aramid, polycarbonate, polyether sulfone or the like is preferably used. The thickness is not particularly limited, but is usually 10
˜75 μm is used. In addition, at least one surface of the resin film may be appropriately subjected to surface treatment such as corona discharge treatment, low temperature plasma treatment, and sandblast treatment.

The flexible printed wiring board of the present invention is manufactured, for example, as follows.

That is, first, the adhesive composition of the present invention is dissolved in a solvent as described above (resin solid content concentration is 20%).
˜50% by weight), an adhesive solution is prepared.

Then, the adhesive solution is applied to one surface of a film made of a polyimide resin or the like, and then dried to prepare a coverlay film. The thickness of the adhesive layer in the coverlay film is preferably set in the range of 1 to 100 μm, more preferably 10 to 50 μm. The drying is carried out by passing through a furnace in which hot air drying, far-infrared heating, high frequency induction heating, etc. are performed, and usually 40 to 250 ° C.
At a temperature of 70 to 180 ° C. for about 2 to 10 minutes. A release film may be temporarily laminated on the adhesive-coated surface of the coverlay film thus obtained for storage and the like. As the releasable film, known materials such as polyethylene terephthalate film, polyethylene film, polypropylene film, silicone release treated paper, polyolefin resin coated paper, TPX film and fluorine resin film are used.

On the other hand, a copper foil circuit board using a polyimide resin film is prepared by a conventionally known method. And
The adhesive-coated surface of the coverlay film (if the release film is laminated, peel it off) obtained as described above is used as the copper foil circuit surface of the circuit board (printed wiring pattern is formed). The surface is laid on the upper surface), and a vacuum press is used to reduce the pressure so that air bubbles do not enter, and the airtightness is improved by pressing at a pressure of 1-5 MPa for 10 seconds-1 minute. Then, after heating (60 to 250 ° C., preferably 100 to 200 ° C. for 1 to 20 minutes) in a reduced pressure state, after-curing is performed at 100 to 200 ° C. for 20 to 60 minutes in a heating furnace or the like. In this way, the desired flexible printed wiring board can be obtained.

In the flexible printed wiring board thus obtained, the glass transition temperature of the adhesive layer after curing is preferably set in the range of 70 to 120 ° C. That is, when the glass transition temperature is less than 70 ° C., the sliding flexibility under high temperature conditions is not sufficient, and conversely, 1
This is because if the temperature exceeds 20 ° C., the adhesive strength of the adhesive layer with respect to the base material or the like decreases, which may cause delamination. The glass transition temperature of the cured product can be measured, for example, by DSC (differential scanning calorimetry).

Next, examples will be described together with comparative examples.

First, the following materials were prepared prior to the examples and comparative examples.

[Thermoplastic Resin (Component A)] Alcohol-soluble polyamide resin

[Phosphorus-containing phenoxy resin (component B)] ERF001-4AF30 (phosphorus content 4.6% by weight,
(Manufactured by Tohto Kasei Co., Ltd.)

[Phosphorus-containing epoxy resin (component C)] FX-289BEK75 (phosphorus content 2.0% by weight, manufactured by Tohto Kasei Co., Ltd.)

[Curing agent (D component)] Melamine resin (MX-750, Sanwa Chemical Co., Ltd.)

[Curing Accelerator] 2-Undecylimidazole (Curezol C11Z,
(Shikoku Kasei)

[Curing accelerator] 1,2,4-benzenetricarboxylic acid (manufactured by Mitsubishi Gas Chemical Co., Inc., F-TMA)

[Flame Retardant] PX-200 (manufactured by Daihachi Chemical Co., Ltd.)

[0051]

Examples 1-5, Comparative Examples 1-3 Tables 1 and 2 below
Each component shown in 1 was added to a solvent consisting of toluene and methanol in the proportions shown in the same table, and dissolved by stirring and dispersed to prepare an adhesive composition solution for a flexible printed wiring board having a solid content concentration of 30% by weight. In addition, Table 1 and Table 2
Also shows the phosphorus content in the adhesive composition.

Then, a polyimide film having a thickness of 12.5 μm was prepared, and the above adhesive composition solution was roll-coated on the surface so as to have a thickness of 20 μm after drying.
It was dried at 60 ° C. for 4 minutes to form an adhesive layer on the surface of the polyimide film. Furthermore, a rolled copper foil having a thickness of 18 μm was prepared, and the copper foil was superposed so as to be in contact with the adhesive layer-formed surface, and thereafter, a vacuum press machine was put into a reduced pressure state and pressed at a pressure of 3 MPa for 30 seconds, 18 as it is
A flexible printed wiring board (sample) was prepared by hot pressing at 0 ° C. for 10 minutes and after-curing at 150 ° C. for 1 hour in an oven.

[0053]

[Table 1]

[0054]

[Table 2]

With respect to the adhesive compositions and flexible printed wiring boards of Example products and Comparative products thus obtained, respective properties were measured and comparatively evaluated according to the following criteria. The results are shown in Table 3 and Table 4 below.
Are also shown.

[Glass Transition Temperature after Curing] Measurement was carried out by a differential thermal analyzer (DSC).

[Peeling Strength] According to JIS C 6481, the peeling strength when peeling the polyimide film from the copper foil at 23 ° C. was measured. In addition, a material that was broken without delamination was indicated as "material break".

[Solder Heat Resistance] According to JIS C 6481, a test was conducted under the following conditions. Solder bath temperature: 260 ° C. Immersion time: 60 seconds Then, the presence or absence of abnormal appearance such as swelling or peeling of the adhesive layer was visually evaluated. As a result, those in which no abnormalities in appearance such as swelling and peeling were confirmed were indicated by ◯, and those in which abnormalities in appearance such as swelling and peeling were confirmed were indicated by x.

[Flame Retardancy] Each flexible printed wiring board was subjected to a flame retardancy evaluation test in accordance with UL-94. Then, those which passed the above standard (VTM-0 class) were evaluated as ◯, and those which failed were evaluated as x.

[High temperature sliding flexibility] JIS C 6471
In accordance with the above, each flexible printed wiring board was tested with a high-speed bending tester for flexible printed wiring board at a frequency of 1500 cpm,
Stroke 20 mm, radius of curvature 2.5 mm, temperature condition 8
A bending test was performed at 0 ° C., and the number of times of bending until the increase in resistance value due to the occurrence of cracks in each sample reached 20% or more of the initial value was measured. As a result, those of 2 × 10 ⁶ times or more were marked with ◯ and those of less than 2 × 10 ⁶ times were marked with x.

[0061]

[Table 3]

[0062]

[Table 4]

From the results of Tables 3 to 4 above, all the example products were excellent in all characteristics. On the other hand, in Comparative Example 1, the contents of B and C components were small,
Therefore, it can be seen that the flame retardancy is lacking. Further, in Comparative Example 1, since the D component was not used, it was found that the glass transition temperature was low and the high temperature sliding flexibility was also lacking. In Comparative Example 2, the polyamide resin (A
It is understood that the component) and the epoxy resin (component C) are not used in combination, and therefore, delamination is likely to occur and the solder heat resistance is also insufficient. Then, in Comparative Example 3, although the flame retardancy was sufficiently obtained, it was found that satisfactory results were not obtained in the peel strength because the epoxy resin (component C) was not used.

[0064]

INDUSTRIAL APPLICABILITY As described above, the flame-retardant adhesive composition for flexible printed wiring boards of the present invention uses a thermoplastic resin and a curing agent, and as a flame-retardant component, a phosphorus-containing phenoxy resin and a phosphorus-containing epoxy. Since a resin is used, when this is used to form the adhesive layer of a flexible printed wiring board, not only flame retardancy and sliding bendability but also strong adhesion to a polyimide resin substrate etc. can be obtained. Therefore, problems such as delamination do not occur. Further, the adhesive composition does not contain a halogen-based compound or an antimony compound, and does not adversely affect the environment.

In particular, when the content ratio of the phosphorus-containing phenoxy resin, the phosphorus-containing epoxy resin, and the curing agent to the thermoplastic resin is set within the specific range in the adhesive composition, the composition is more robust to the polyimide. Adhesiveness can be obtained.

Further, when the thermoplastic resin in the adhesive composition is a polyamide resin, it is possible to obtain stronger adhesion to polyimide.

Furthermore, when the phosphorus content in the adhesive composition is set within a specific range, UL-94-
High flame retardancy of VTM-0 class can be obtained.

When the glass transition temperature of the cured product of the adhesive composition is set in a specific range, high sliding flexibility can be obtained even under high temperature conditions.

The flexible printed wiring board of the present invention comprising the above adhesive composition has high flame retardancy and
Since it does not contain halogen compounds or antimony compounds, it does not generate harmful substances such as dioxins during combustion, and is extremely safe.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/03 670 H05K 1/03 670Z 3/38 3/38 E (72) Inventor Takayuki Shimizu Komaki Aichi Prefecture 3-chome, Higashi-City, Tokai Rubber Industrial Co., Ltd. (72) Inventor Shigeshi Yamada 1-1, Funami-cho, Minato-ku, Aichi Prefecture Nagoya, Toagosei Co., Ltd. Functional Product Laboratory (72) Inventor, Yoshio Taniguchi 1-Funami-cho, Minato-ku, Nagoya-shi F-term in Functional Product Research Laboratory, Toagosei Co., Ltd. (reference) 4J040 EC001 EE061 EG021 GA04 GA26 HB22 HC01 KA16 KA36 LA08 NA20 5E343 AA18 AA33 CC03 CC04 CC07 GG02 GG16 GG20

Claims (6)

[Claims] 1. A flame-retardant adhesive composition for flexible printed wiring boards, which comprises the following components (A) to (D) as essential components. (A) Thermoplastic resin. (B) Phosphorus-containing phenoxy resin. (C) Phosphorus-containing epoxy resin. (D) Curing agent. 2. The flame retardant adhesive composition comprising (A) to (A)
The content ratio of (D) is 100 parts by weight of (A),
The flame-retardant material for flexible printed wiring boards according to claim 1, wherein (B) is set in a range of 50 to 500 parts by weight, (C) is set in a range of 20 to 200 parts by weight, and (D) is set in a range of 3 to 50 parts by weight. Adhesive composition. 3. The flame-retardant adhesive composition for a flexible printed wiring board according to claim 1, wherein the thermoplastic resin (A) is a polyamide resin. 4. The phosphorus content of the adhesive composition is 2% by weight.
The flame-retardant adhesive composition for flexible printed wiring boards according to claim 1, which is set as described above. 5. The glass transition temperature of the cured product after curing is 70.
The flame-retardant adhesive composition for flexible printed wiring boards according to any one of claims 1 to 4, wherein the flame-retardant adhesive composition is set in a range of 120 ° C to 120 ° C. 6. A flexible printed wiring board comprising the flame-retardant adhesive composition for a flexible printed wiring board according to claim 1.