JPH0322431B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesive for heat-resistant films, and more specifically, (a) a polyfunctional cyanate ester having two or more cyanato groups in the molecule, a prepolymer of the cyanate ester, or a prepolymer of the cyanate ester and an amine. A curable resin composition containing as an essential component a polymer, a polyfunctional maleimide having two or more N-maleimide groups in the molecules a and b, the maleimide prepolymer, or the prepolymer of the maleimide and amino. ) 65-99 wt% of component () based on the sum of component () and (), component, ()
This is an adhesive composition for heat-resistant film having a content of 1 to 35 wt%, in which the components () a and b are respectively represented by the general formulas (1) and (2) below, and the component () polyester is The number average molecular weight of vinyl acetate is 50,000~
150,000, and is particularly useful as an adhesive for polyimide films. Traditionally, adhesives for polyimide films include:
Epoxy resin adhesives are used, but many defects occur due to insufficient heat resistance. In addition, cyanate resins and cyanate ester-maleimide resins made by mixing cyanato resins with polyfunctional maleimide groups having two or more N-maleimide groups are known (Japanese Patent Publication No. 1928-1928 (component a), 46
-41112 (composition of a + epoxy resin (c)), 54-
30440 (composition of a+b), Publication No. 52-31279 (a
+b+c composition), when this resin was used as an adhesive, the adhesive strength with the polyimide film was insufficient. Furthermore, polyvinyl acetate resin has excellent adhesive properties, and adhesive compositions are known in which it is mixed with epoxy resin or phenol resin, but as mentioned above, this adhesive has poor heat resistance. It was hot. The present inventor discovered that a resin composition prepared by mixing polyvinyl acetate with a cyanato resin or a cyanate ester-maleimide resin has excellent adhesive properties and exhibits very little deterioration in heat resistance, and furthermore, it is suitable for use in polyimide films. They discovered that it is also extremely excellent as an adhesive, and completed the present invention. The present invention will be explained below. First, component (a) of the adhesive composition of the present invention: cyanate ester resin, or a+b: cyanate ester-maleimide resin will be explained. Suitable compounds as the multifunctional cyanate ester of component a are those represented by the following general formula (). R(-O-C≡)m...(1) [m in the formula is an integer of 2 or more and usually 5 or less, and R
is an aromatic organic group, and the cyanate ester group is bonded to the aromatic ring of the organic group R] Specific examples include 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-, 1,6-, 1,8
-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,
4-dicyanite biphenyl, bis(4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(3,5-
dichloro-4-cyanatophenyl)propane,
2,2-bis(3,5-dipromo-4-cyanatophenyl)propane, bis(4-cyanatophenyl)ether, bis(4-cyanatophenyl)thioether, bis(4-cyanatophenyl)sulfone, tris(4-cyanatophenyl)phosphite, These include tris(4-cyanatophenyl) phosphate and cyanic acid esters obtained by reacting nopolac with cyanogen halides. In addition to these, Tokuko Sho 41-1928, Tokko Sho 43-
18468, Special Publication No. 44-4791, Special Publication No. 11712-11712, Special Publication No. 46-41112, Special Publication No. 47-26853, and Special Publication No. 1977-26853.
Cyanic acid esters described in 63149 and the like can also be used. In addition, the above-mentioned polyfunctional cyanate ester can be polymerized in the presence of a catalyst such as a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, or a phosphoric acid ester such as tributylphosphine, or an amino compound as described below can be prepared. It can be used as a prepolymer obtained by reacting with A polyfunctional cyanate ester single prepolymer generally has a sym-triazine ring in the molecule, which is formed by trimerization of the cyanide groups in the cyanate ester. In the present invention, the number average molecular weight is 400~
Preferably, 6000 of the above prepolymers are used. The polyfunctional maleimide of component b of the present invention has the following general formula (2) [In the formula, R is a divalent, usually 5 or less, aromatic or aliphatic organic group, X ¹ and X ² are hydrogen, halogen, or an alkyl group, and m is 2 or more and usually 5 or less It is. ] It is a compound represented by The maleimide represented by the above formula can be produced by a method known per se, in which maleic anhydride and a polyamine having 2 to 5 amino groups are reacted to prepare maleamic acid, and then the maleamic acid is cyclodehydrated. . The polyamines used are preferably aromatic amines in terms of heat resistance of the final resin, but if flexibility and flexibility of the resin are desired, alicyclic amines may be used alone or in combination. good. Furthermore, it is particularly desirable that the polyvalent amines be primary amines in terms of reactivity, but secondary amines can also be used.
Suitable amines include meta or paraphenylene diamine, meta or para xylylene diamine, 1,4- or 1,3-cyclohexane diamine, hexahydroxylylene diamine, 4,
4'-diaminobiphenyl, bis(4-aminophenyl)mene, bis(4-aminophenyl)ether, bis(4-aminophenyl)sulfone, bis(4-amino-3-methylphenyl)methane, bis(4-amino-3 ,5-dimethylphenyl) metal, bis(4-aminophenyl)cyclohexane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-amino-3-methylphenyl)propane, bis(4-amino -3-chlorophenyl)methane, 2,2-bis(3,5-dipromo-4-aminophenyl)propane, bis(4-chlorophenyl)methane,
-aminophenyl) phenylmethane, 3,4-diaminophenyl-4'-aminophenylmethane,
These include 1,1-bis(4-aminophenyl)-1-phenylethane, melamines having an s-triazine ring, and polyamines made by reacting aniline with formalin and linking benzene rings with methylene bonds. In the present invention, the above-mentioned polyfunctional maleimide can be used in the form of a prepolymer or a prepolymer with the above-mentioned polyamine instead of being used in the form of a so-called monomer. Next, the polyvinyl acetate of the component () of the present invention is a known one obtained by polymerizing vinyl acetate, and in the present invention, the polyvinyl acetate has a number average molecular weight,
50,000 to 150,000 is preferred. The method for preparing the adhesive composition of the present invention includes using components () and () as solvents, such as ketonic acids such as methyl ethyl ketone and acetone, esters such as ethyl acetate, and polar solvents such as N,N-dimethylformamide. A method of mixing a solution dissolved in a suitable inert organic solvent at room temperature or under heating, or a method of mixing without a solvent using, for example, a Banbury mixer, a roll, an extruder, etc. In addition, the composition ratio can be used within any range, but when used as a heat-resistant adhesive, the component () should be 65 to 99 wt%, preferably 65 to 99 wt%.
It is preferable to use 70 to 95 wt%, and the second component () to 35 to 1 wt%, preferably 30 to 50 wt%. Of course, it can be used in applications where heat resistance is not required, with a smaller range of component (). In addition to the above components, the adhesive composition of the present invention includes epoxy resin, polyester resin, phenoxy resin, (meth)acrylic ester, epoxy ester of (meth)acrylic acid, and epoxy ester of (meth)acrylic acid. Esters of (meth)acrylic acid such as alkenyl esters and their prepolymers; diallyl phthalate, divinylbenzene,
Epoallyl compounds such as diallylbenzene and trialkenyl isocyanurate and their prepolymers: Dicyclobentadiene and its prepolymers: Phenol resins: Polyvinyl acetal resins such as polyvinyl formal, polyvinyl acetal, and polyvinyl butyral; OH groups or
Acrylic resin with COOH group, silicone resin,
Alkyd resin; polybutadiene, butadiene
Acrylonitrile copolymer, polychloroprene,
Liquid-elastic materials such as butadiene-styrene copolymer, polyisoprene, butyl rubber, natural rubber, etc.
Rubbers, polyimide polymers, etc. can be used as appropriate. The adhesive composition of the present invention itself has the property of being bonded by heating and forming a network to form a heat-resistant resin, but in order to promote cross-linking and forming a network, it is usually used in the form of a catalyst. Such catalysts include 2-methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2
-Phenylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2ethyl-4- Imidazoles exemplified by methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-guanaminoethyl-2-methylimidazole, as well as trimellitic acid adducts of these imidazoles, etc. ;N,N-dimethylbenzylamine,
N,N-dimethylaniline, N,N-dimethyltoluidine, N,N-dimethyl-p-anisidine,
p-halogen-N,N-dimethylaniline, 2-
N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, N,N,N',N'-tetramethylbutanediamine, N-methylpiperidine, etc. Tertiary amines; phenols such as phenol, cresol, xylenol, resorcin, catechol, phloroglucin; lead naphthenate, lead stearate, zinc naphthenate, zinc octylate, tin oleate, dibutyltin maleade, manganese naphthenate, Organic metal salts such as cobalt naphthenate and iron acetylacetonate; inorganic metal salts such as SuCl ₄ , ZnCl ₂ , AlCl ₃ ; benzoyl peroxide, lauroyl peroxide, capri, luperoxide, acetyl peroxide, parachlorobenzoyl peroxide, jeter Peroxides such as sharybutyljeeperbutarate; maleic anhydride, phthalic anhydride, lauric anhydride, pyromellitic anhydride,
trimellitic anhydride, hexahydrophthalic anhydride,
Examples include acid anhydrides such as hexahydrotrimellitic anhydride and hexahydropyromellitic anhydride, and azo compounds such as azopisnitrile. The amount of the catalyst to be added is generally sufficient within the catalytic amount range, for example, it may be used in an amount of 10% by weight or less based on the total composition. The temperature for curing the curable adhesive composition of the present invention varies depending on the presence or absence of a curing agent and catalyst, the types of composition components, etc., but it is usually selected within the range of 100 to 300°C. . Also, it is preferable to apply pressure during heat curing, generally speaking 0.1
Appropriately selected within the range of ~500Kg/ ^cm2 . Various additives may be added to the adhesive composition of the present invention as long as the original properties of the composition are not impaired. Examples of these additives include various known additives such as fiber reinforcing base materials, fillers, dyes and pigments, lubricants, coupling agents, and flame retardants. The present invention will be specifically explained below using Examples and Comparative Examples. Example 1 Polyvinyl acetate (trade name: Sakunor
After adding 250 g of SN-10N (manufactured by Denki Kagaku Kogyo Co., Ltd.) and dissolving it in toluene at 100°C, 0.1 g of iron acetylacetonate and 0.7 g of benzoyl peroxide were added as catalysts to obtain a uniform varnish. This varnish was applied to a 125μ thick polyimide film (product name: Kapton, manufactured by Du Pont),
The mixture was heated at 120° C. for 15 minutes and dried to produce a B-stmge adhesive film. Electrolytic copper foil with a thickness of 35 μm was layered on the adhesive side of this film, press-molded at a pressure of 20 kg/cm ² and a temperature of 140°C for 30 minutes, cooled, and further heated to 140°C in an oven.
It was then cured for 10 hours. The test results for this copper-clad film are shown in Table 1. Comparative Example 1 Table 1 shows the results obtained in the same manner as in Example 1, except that a varnish prepared by dissolving the polyvinyl acetate alone used in Example 1 in toluene was used. Comparative Example 2 Table 1 shows the results of Example 1 except that the polyvinyl acetate resin was not used.

【table】

[Table] Peeling occurred between.
Example 2 900 g of 2,2-bis(4-cyanatophenyl)propane and 100 g of bis(4-maleimidophenyl)methane were pre-reacted at 150°C for 160 minutes, and this was mixed with polyacetic acid similar to that used in Example 1. vinyl
A solution of 200g dissolved in toluene, 0.1g of zinc octylate and 0.1g of triethylenediamine as a catalyst,
0.5 g of benzoyl peroxide was added and mixed uniformly to obtain a varnish. This was applied to one side of a polyimide film similar to that used in Example 1, and heated and dried at 110° C. for 30 minutes to produce a B-stage adhesive film. Electrolytic copper foil with a thickness of 35 μm was layered on the adhesive side of this film and press-molded at a temperature of 175°C and a pressure of 30 kg/cm ² for 100 minutes, and then further heated at 200°C in an open environment for 10 minutes.
After an hour it was cured. The test results for this copper-clad film are shown in Table 2. Comparative Example 3 Table 2 shows the same results as in Example 2 except that polyvinyl acetate was not used. Reference Example 1 Table 2 shows the same procedure as in Example 2 except that an epoxy resin adhesive was used instead of the adhesive varnish in Example 2.

[Table] Peeling occurred between the adhesive layer and the adhesive layer.

Claims (1)

[Scope of Claims] 1 () a A polyfunctional cyanate ester having two or more cyanato groups in the molecule, a prepolymer of the cyanate ester, a prepolymer of the cyanate ester and an amine, or the above a and b A curable resin composition containing a polyfunctional maleimide having two or more N-maleimide groups in the molecule, a prepolymer of the maleimide, or a prepolymer of the maleimide and an amine is mixed with () polyvinyl acetate. Based on the sum of the components () and (), component () 65 to 99 wt%, component () 1
Adhesive compositions for heat-resistant films in the range of ~35wt%. 2 The ()a and b components each have the following general formula
The adhesive composition according to claim 1, represented by (1) and (2). General formula (1): R(-O-C≡)m...(1) (m in the formula is an integer of 2 or more and usually 5 or less, and R is an aromatic organic group, The acid ester group is bonded to the aromatic ring of the organic group R.) General formula (2) (In the formula, R is a divalent, usually pentavalent or higher, aromatic or alicyclic organic group, and X ¹ and X ² are hydrogen, halogen,
or an alkyl group, where m is 2 or more and usually 5 or less. 3. The adhesive composition according to claim 1, wherein the polyvinyl acetate () has a number average molecular weight in the range of 50,000 to 150,000.