JPS58204073A - Adhesive composition - Google Patents

Abstract

PURPOSE:To provide an adhesive compsn. having excellent adhesion and low flow of resin, by incorporating a bisphenol A-type epoxy resin, poly-N-glycidyl type epoxy resin, carboxyl group-contg. nitrile rubber, and specific clay. CONSTITUTION:A bisphenol A-type epoxy resin of epoxy eq. 170-4,000(A), poly-N-glycidyl type epoxy resin contg. a group of the formula (wherein n is 1- 6) (B), nitrile rubber contg. 1-8wt% carboxyl group (C) (e.g., carboxyl-terminated acrylonitrile/butadiene copolymer rubber), and pulverized silica and/or clay treated with an onium compd. (e.g., trialkylallylammonium salt) (D) are blended to attain the wt. ratio of 0.05<=B/A<=19, 0.05<=A+B/C<=2, 0.0125<=D/C<=0.75. The resulting compsn. is applied to a heat-resistant resin film and processd into B-stage, and then a metal foil is laid on the surface of said film to yield a printed board by applying heat and press.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive composition which is mainly used for manufacturing flexible printed circuits, and which has particularly excellent adhesive strength and low resin flow.

Conventionally, polyimide film or polyester film is commonly used for flexible printed circuit boards, and metal foils such as copper foil or aluminum foil are bonded onto this film using an adhesive, and it is used as a flexible printed wiring material for cameras,
It was used in many fields such as calculators and telephones. The properties required of this adhesive for printed circuit boards include not only adhesive strength between the film and metal foil, but also electrical properties and high-temperature melting (
1) Solder heat resistance that does not cause abnormalities such as blistering even when immersed in water, chemical resistance to solvents such as methylene chloride used to melt parts other than circuits, flexibility necessary for free three-dimensional wiring, etc. However, as the production volume of printed circuit boards increases year by year and the design of circuits becomes more complex, there is a need for more reliable and high-performance adhesives.

However, conventionally known adhesives for printed circuit boards include fluororesin, epoxy nopolanol, nitrile-phenol, polyester, and acrylic adhesives, but these adhesives do not sufficiently meet the above-mentioned required characteristics. No adhesive has yet been found that combines these characteristics.

In order to improve the insulation properties of flexible circuits,
After processing a circuit on a film substrate with a film and metal foil bonded together, a method is often used in which a so-called insulating film, in which an adhesive is applied to one side of the film, is bonded, but conventionally this insulating film is bonded by heat and pressure. When doing so, the adhesive layer of the insulating film protrudes into the pad area, which is an undesirable phenomenon known as resin flow.

As a result of intensive studies to eliminate the disadvantages of conventional adhesives for printed circuit boards, the present invention has developed a high-performance adhesive that fully satisfies the above characteristics, has particularly excellent adhesive properties, and has low resin flow. The drug composition was successfully developed.

That is, the composition of the present invention comprises (a) bisphenol A epoxy resin, (b) polyN
-Glycidyl-type epoxy resin.

(C) Nitrile comb containing carboxyl group, (d
) Comprised of finely powdered silica or/and clay treated with onium compounds.

The composition of the present invention will be explained in detail below.

/a) Bisphenol A of the present invention! ! ! The epoxy resin is represented by the general formula (where n=o, an integer of 1, 2.3, etc.)
1, preferably one having an epoxy equivalent of 170 to 4,000. These can be obtained commercially.

Next, (b) poly N-glycidyl type epoxy resin can generally be synthesized with the corresponding amine and ebinolohydrin, but even if the amine group of the intermediate is further reacted with an epoxy group to increase the molecular weight, good. Examples of component (b) include (however, R and R' above are hydrogen or alkyl groups).

As the nitrile group having a carboxyl group as the component (C), for example, acrylonitrile and butadiene are used at a ratio of about 5/! Acrylonitrile-butadieno copolymer rubber copolymerized at a molar ratio of J5-45/55 with a carboxyl group at the end, or together with acrylonitrile and butadiene, an IF-composable monomer containing a carboxyl group such as acrylic acid, ζ A copolymerized rubber made by copolymerizing the resin and the like is used. The carboxyl group content in the copolymer rubber is preferably about 1 to 8 weight 9≦. Furthermore, as the molecular weight of component (C), (C□) has a number average molecular weight of less than 5,000, preferably J, (JOO-4000), and (C2) has a number average molecular weight of 5,000 or more, preferably 8.
000 to 50,000 in combination, resin flow is improved while maintaining high adhesive strength. in this case(
The self-combination ratio (weighting) of the C□ component and the (C2) component is 02≦(C□)/((C□) + (C2))≦09
If used in combination so as to satisfy the condition of 0, even more preferable results can be obtained. If this value is less than 0.2, the adhesive force is improved, but the resin flow tends to increase, while if it exceeds 0.96, the adhesive force υ- tends to decrease.

(c) Component 1 is generally liquid, and for example, products from Guttrich, known as products r1 such as Hiker C']'BN, /% Squid=QTBNX, are commercially available. Component (C3) is generally solid at room temperature, and includes No. Squid, ], O'72 (Gutudrich), Nibor 107z (Nippon Zeo 7), Chemi Gum 550, Tailac 221 A, and others. 1d21], A, and other trade names.

What can be used as component (d) are clays treated with finely powdered silica and onium compounds.

Of course, both can be used alone or in combination.

An example of finely powdered silica is amorphous silica, which is obtained by combustion and hydrolysis of silicon tetrachloride in an oxyhydrogen flame.
It is sold under the trade name I, and can be preferably used.

The other component (d), clay treated with an onylum compound, is bettonite, montmorillonite,
By treating clay, such as sepiolite, with onium compounds such as ammonium compounds, phosphonium compounds, and sulfonated compounds, the swelling properties of the clay with respect to organic compounds can be improved. It is also referred to as jiki-kare 1, and is a well-known substance, U.S. Patent 2.!, '41, 4
1. The manufacturing method and properties are described in detail in /.

Among the above onium compounds, ammonium compounds are preferred, and salts of aliphatic amines, alicyclic amines, aromatic amines and heterocyclic amines, and of course salts of primary amines, secondary amines, tertiary amines, and Quaternary ammonium compounds are also preferred examples.

Where I'll go! Usually, it is carried out by suspending clay in water and then adding an aqueous solution of an onium compound to the reaction.
Zru. Thereafter, the desired product is obtained by filtration, washing, drying, and pulverization.

This treated clay is commercially available, such as bentone;
“?, Benton 34, Benton 38, Benbin SA-:
l, f', (N, lJ-Tindustries)
For example, products such as can be used preferably.

The adhesive force and resistance of the adhesive composition of the present invention are greatly improved compared to the toilet Cζ of Kone et al. (d-) 1J'75+.

Next, the mixing ratio of (,), (b), ((・), (d) (
(weight basis) will be explained.

(a) Bisphenol A type epoxy resin which is b'2 minutes, 1. : The mixing ratio with the poly N-glycidyl type epoxy resin which is the component (b) is 0.05≦(b)/(
a) 51! l is preferred l-, < .

] If it exceeds 9, heat resistance is good but adhesive strength decreases, while if it is less than 0.05, heat resistance and adhesive strength decrease.

Furthermore, the mixing ratio of the nitrile rubber having a carboxyl group, which is the component (C), and the epoxy resin is 1d, +3
．． 07+≦((a)+(b)), /(C)≦,
If it exceeds 1, the adhesive strength will decrease to a large extent, and if it is less than O, O or J, the adhesive strength and heat resistance will decrease.

The pupil used for the (d) component is usually 0.01:)5”'-(d
) /”(C) “○,’/ ,”,+ formula is preferably satisfied, and furthermore, 0.06 <’ (a,) /
(c)≦0.36 is more preferable. (d) / (c)
I like it a little.

Adhesive strength decreases and resin flow to the pad portion during crimping is significant. Also, if (d) / (C) is too large, 4
a The adhesion strength decreases and the adhesive layer becomes non-uniform, resulting in an unfavorable aesthetic appearance when using a transparent film.

When preparing an adhesive composition using the above components (a), (b), (c), and (a), the four components are usually Q
It is sufficient to mix it with (a) and (b), or (b) and FC depending on the purpose of use, such as adjusting the viscosity and tackiness.
) or ld (a) and (1,) /l: b:) may be pre-reacted with gold in advance.

The adhesive composition of the present invention can use all common epoxy resin curing agents, such as aliphatic and aromatic polyamines, acid anhydrides, hydrazide compounds derived from polycarboxylic acids, imidazole derivatives, and dicyandiamide. , guanidine derivatives, and vidiamide derivatives are representative examples. More specifically, diaminodicyclomethane, bis(4-amino-3-methylcyclohexyl)methane, 7-acinodiphenylmethane, diaminodiphenylsulfone, 4,4'-diamino-3,3'dichlorodiphenylmethane, Phthalic anhydride, chlorendinocic anhydride, Shikoku Kasei product Curezo) b 31'=
4 M Z A 21 N B'-, Curesol 2E
4MZ-ON.

Examples include Gyanol 2PZ-ON.

To accelerate curing, imidazole derivatives, Ami/boron trifluoride complex, SanAbbott product D
BU (diazabijikuro/decene), Ll,, -CA
T-8A No. 1 (DBU phenol salt), U-CAT-SA NO. 02 (DEU・
octylate) etc. can be used in combination with the above-mentioned curing agent as a curing accelerator.

The adhesive composition of the present invention is usually dissolved in a solvent and applied to an adherend. Solvents used in this case include methyl ethyl ketone, methyl isoptylktone, toluene, quinolene, dioxane, ethanol, inonorobyl alcohol, methyl cellosol, ethyl cellonorub, dimethyl formamide, etc., and these are used alone or in combination.

When a solution of the following adhesive composition is applied to an adherend, B-staged (semi-cured state, melts when heated), and then pressed using a roll or batch press, excellent properties can be obtained. A printed circuit board having +[' is obtained. Pressure bonding temperature is HO~:SOO” C1 pressure is 5~200 Kp f
/cm2 is preferably used. ko0 white ~ 350'
By post-curing with C, the heat resistance can be further improved. When long-term heating is required during crimping, an additive can be added to prevent carboxylated nitrile rubber or EBOGI/1 resin from oxidizing or decomposing. The stabilizer is preferably a non-staining stabilizer that does not cause coloring, and an example is Irganonotus 1010 (
Tetrakis-17tyrene-3-(3,1,5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane), Iononox 220 (Sh, product of ell Chem, 4. 4
'-methylene-bis(2,6-di-t-butyl)phenol), Iononox 330 (5hell Che
m company products, ■, hindered phenol stabilizers such as 3,5-trimethyl-2,4,6-tris(+4,5-di-t-butyl-4-hydroxybenzyl)benzene), Tsukrak 300 (large Uchishinsha product, 4,4'-thiobis(b-t-butyl-3-methyl)phenol), CA
O-6 (Ashland Chem product, 21,″-
Thiobisphenol stabilizers such as thiobis(6-t-butyl-4-methyl)2-1-nol), DI, ・rl・
(Yoshitomi Pharmaceutical product, dilauryl thiodiprobinate) and the like can be mentioned.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example] Into a 500z3 separable flask, 2'/ton of 150 ml of water was passed through a 7-unit sieve (N L Indus
l;realcbemicals Hs)! J
Add 14.0y of montmorillonite treated with alkylallylammonium salt, specific gravity 18 (Otj''C)), further add toluene J2LH9 to sufficiently moisten it, and then add !151'rff,% ethanol 4.2y. The mixture was stirred to form a pregel (smooth, ream-like gel).
0~49o, softening point 62~70℃) 21.86y,
Hiker CT B N ] 'K(10X 1:"?
(manufactured by Guttrich, carboxylated nitrile rubber,
Number r-average molecular weight 3500, carboxyl fund t2
．． <'3 Weight □9, Viscosity 550,0000 P S (
27℃) ) , 5], , Oy, dipole 1 (] '
7 ::: (Nippon Zeon Co., Ltd., number average molecular weight 30,00
0, carboxylated nitrile rubber, mu''--viscous E,
"50" LJO) is masticated in advance with a roll,
Pieced into small pieces 34.0 y, methyl ethyl ketone 2 J
, 9.4y, and stirred at room temperature until a homogeneous solution was obtained to dissolve C7,4/ζ.

Tetradose X (Mitsubishi Gas Chemical Co., Ltd., N,
N, N', N', -tetraglycidyl-m-xylylene diamide/epoxy, total 95 to 1.10. Viscosity 2
000~/1000) 20.6y was added and dissolved again to prepare a main ingredient.

Next, as a curing agent component, 3,3'-diaminodiphenylsulfone 15.2 y1 diazabisic['undecene 1. ()y, A solution prepared by dissolving 0.024y of triphenylphosphine in methyl cellosolve 81.2F was mixed with all h11-base ingredients to prepare an adhesive composition.

This adhesive solution was applied onto Kapton film (polyimide film manufactured by DuPont) and placed in an air oven for 13 hours.
After drying for 10 minutes at 0''C, and gluing the treated surface 61 of the copper foil together, preheating at 70℃ for 2 minutes: +
Kp/ was pressed with a press for ()0 minutes under the conditions of 3. The thickness of the adhesive layer of this sample was 22 to 25 μm. The T-type beer strength is 1.6Vf/(7), and 2
Even when the copper foil was floated for 2 minutes in an I'-1 + I bath at 80 DEG C., no noticeable blisters or the like occurred.

゛Separately, an adhesive solution was applied onto the Kapton film, and after drying for 130°C%IO minutes, a circular hole with a diameter of 8) #m was made and the film was pasted onto the mirror surface of the copper foil on a press. 170'C% After preheating for 2 minutes, L'10°C
It was crimped with a press for 40 minutes under the conditions of 115K and P/cm2. The thickness of this adhesive layer is 3. The maximum length of the adhesive flowing into the hole is O, O,' (J
It was more than a.

Leprosy example 2 Hiker e '1' in a 500m3 separable flask
HN1300 x 1370. Oy, R-301,
18.0yol and methyl cellosolve BB, Of were added and allowed to dissolve at room temperature. Separately, 1) 168y of vent/::'s was gradually added to 450y of methyl cellosolve which was being stirred at high speed with a homomixer to prepare a suspension.
The entire amount was added to the above solution. Furthermore, Erosil 380
(B Hon Aerosil? 1 fine powder paste) 88y and Tetrado

Add to the above ingredients 3,'-diaminodino-nylsulfo 712.5y, diazabi/crow/teseno 0,
SOy,') Riphenylphosphine/○02y dissolved in methyl cellosolve 3'7.45i and the entire amount of the curing agent component was added and mixed to obtain an adhesive composition.

Apply the above adhesive composition to the caputo/film.

1,') After drying at 0℃ for 10 minutes, apply it to the treated surface of the copper foil, and after preheating on a press at 170℃ for 2 minutes,
"(1,") Pressing was carried out for 40 minutes under a press condition of 5 KP/cm2.

The thickness of the adhesive layer was 22 to 25 μm. The T-peel strength was 2.1 KP/1 MT, and no abnormalities such as blistering were observed even when the copper foil was floated in a solder bath at 280° C. for 2 minutes with the copper foil facing down. The maximum length of the adhesive flow was 0.1 mm.

Examples 3 to 6 The curing agent components shown in Table 1 were mixed with the main component having the same composition as in Example 1 to prepare adhesive compositions, and the same tests as in Example 1 were conducted. The results are shown in Table 1.

Example 7: Into a HyOC1tyn3 flask, 501 parts of octadentrimethylammonium acetate and 12.5 parts of methanol were added.
crrr” fjM+E, after dissolving, add Eto Plus SP (Take 11J Yakusori, manufactured by a certain company, Sepiolite, 10
0 to 325 mesh) were stirred and mixed at υ11. It was placed in an evaporating dish, dried in a 50□ (7 bag 3-m open chamber, and then ground in a mortar to [- minutes. The same main component and curing agent component as in Example 1 were prepared and tested. 12 ~:,:,,μm, and the T-type beer strength is]
, 6Ky/lyn. Even after floating in a solder bath at 0°C for z minutes, no visible signs of Fukusaw 1 were observed.

Also, when crimping with copper foil mirror surface 1- (1,5K, P/nm
2) The length of the adhesive flow was Q4M or less.

Comparative Example 1 Actual Ai! i i+111, Benton z゛? The preparation and operation of the adhesive composition as in Example 1 was repeated without using. The T-type beer strength is [411K7/α, and the maximum length of the flow of adhesive between Kapton film copper foil mirror surfaces is:
It was 1.0j13 or more.

Middle Example 8 In Example 1, instead of tetradose, N, N, N
', N', N'', N''-hexaglycidyl-1,3,5
Exactly the same procedure was performed except that -triaminomethylbenzene (epoxy equivalent weight 90) was used.

The T-peel strength is 1.5K17cm, and the solder heat resistance is U280, which did not cause any blisters even when placed on a solder bath for 0.2 minutes.The maximum length of adhesive protrusion is 00.
It was less than 3 elbows.

Example 9 The same operation as in Example 2 was performed except that fine powder silica (Aeroseal 380) 6.8jiE was used instead of Pent/27. The thickness of the adhesive layer between Kapton and copper foil is 22-25 tim, and the T-type beer strength is 209
/σ. No abnormalities such as blistering were observed even after floating in a solder bath at 280℃ for 2 minutes, and the maximum length of adhesive flow when crimping on a copper foil mirror surface (15K/cm") was o, It was 1 inch.

Agent: Patent Attorney Masaru I L. Document of Amendment to Procedural Procedures Hi, 5' Display of 41 cases 1982 Patent Application No. 86782, Title of Invention Relationship with the Adhesive Composition Amendment Case Patent Applicant fl-; ili Chiyo, Tokyo [3-2 Kasumigaseki, H-ku
No. 5 L'”r (6th name) (588) Tamai Petrochemical T Gyo Co., Ltd. Representative Seiki Nakano, Agent Address: 240-01 Date of amendment order Contents of voluntary amendment (1) Scope of claims Fill out the supplementary IF column as shown in the attached sheet.

(2) Add +H to page 7 of the specification as follows.

"Copolymerized rubber etc. are used. Jt,
Q-“The carboxyl fund in Gocom is about 1~8 times ψ%
It is preferable that the degree of Examples of such products include Hiker〇TBN, Hiker CTBNX, /..., Squid-1072 (manufactured by L Gutdrich), and Nipol 10.
72 (manufactured by Nippon Zeon Co., Ltd.), other chemigum 550. They are numbered with product names such as TAIRAK 221A or 211A. (3) Delete lines 1 and 2 on page 8.

More than 1 unit Attachment “2. Scope of claims 1. An adhesive composition consisting of the following (a) to (d).

(a) Bisphenol A type epoxy resin, (b) Poly N
-Glycidyl-type epoxy resin.

(C) Nitrile rubber containing a carboxyl group.

(d) Finely powdered silica has/and has been treated with an onium compound and has a viscosity of ゛2. A composition according to the first claim.

0.05≦(b)/(a)≦18 0.05≦((a)+(b))/(c)≦20
．． 0125≦(d), /(c)≦0.75 J
Supplementary Procedures-E-Zan IV+March 1980/'/-I+ Commissioner of the Japan Patent Office Kazuo Wakasugit, 1 indication 1988 Patent Application No. 8Ei? No. 82 No. 2, Title of the invention Adhesive composition 3, Relationship with the person making the amendment Patent applicant address No. 2-5 Kasumigaseki 3 "1", Chiyo HJ-ku, Tokyo Name (588) Goi Petrochemical I゛Gyo Co., Ltd. 1 Representative Seiki Nakano 4, Agent 240-01 Address 1601-635 Nagara, Ha 111-cho, Miura-gun, Kanagawa Prefecture Number of inventions increased by amendment 16 Target of amendment (2) Details The claims section of the book shall be amended as shown in the attached sheet.

(3) "Regarding adhesive compositions" on page 2, line 7.
be amended to "Relate to adhesive compositions and printed circuit boards."

(4) "Polyester film" in the 9th line of page 2 is corrected to "heat-resistant plastic film such as polyester film."

(5) "Composition of the present invention" on page 4, line 8 of the same page is corrected to "composition of the present invention and printed circuit board using the composition."

(6) Add the following sentence after the 6th line from page 11 F.

[Among such curing agents, the use of aromatic polyamines is the most superior from the viewpoint that they still have solder resistance □ even after the printed circuit board is left at room temperature and absorbs moisture.

(7) Insert the following sentence between page 13, line 17, l and line 18]1.

[The thus produced substrate in which the heat-resistant plastic film and the metal foil are firmly bonded is extremely excellent as a printed circuit board, especially a flexible printed circuit board. (8) Correct r 15Kg/cm2J on page 15, line 15, page 16, line 4, and page 19, line 16 to r 40Kg/C112J.

(9) r15Kg/cm2J on page 17, line 6 and page 20, line 20 of the same page is r 20Kg/C1112J
and supplementary IF.

Below Attachment [2. Scope of claims 1. An adhesive composition consisting of the following (a) to (d).

(a) Bisphenol A type epoxy resin, (b) Poly N
- glycidyl type epoxy resin, (C) nitrile rubber containing carboxyl groups, (d) clay treated with finely powdered silica or/and onium compound.

2, (a), (b), (C), (d)
The composition according to claim 1, wherein the blending ratio (weight ratio) of satisfies the following formula.

0.05≦(b) / (a)≦19 0.05≦((a)+(b) ) / (c)≦20.
0125≦(d) / (c)≦0 ,,,? 5, then (C carboxyl-

Claims (1)

[Scope of Claims] h. An adhesive composition comprising the following (a) to (d). (a) Bisphenol A type epoxy resin, (b) Poly N
- glycidyl type epoxy resin, (C) nitrile rubber containing carboxyl groups, (d) clay treated with finely powdered silica or/and onium compound. 2. The composition according to claim 1, wherein the blending ratio (weight ratio) of (a), (b), (C), and (d) satisfies the following formula. 0.05≦(b)/(a)≦19 005≦((a) + (b))/(C)≦20.
0125≦(d)/(c)≦0.753(c) A nitrile rubber containing a carboxyl group. (C□) Those with an average molecular weight of less than 5000, and (C2
) The composition according to claim 1 or 2, which is a mixture with a compound having a number/V average molecular weight of 5,000 or more. 4. (C) The blending ratio (weight ratio) of the nitrile rubber containing a carboxyl group is 02≦(Cρ/((C)+
The composition according to claim 3, which satisfies (c,))≦096.