JP2671162B2 - Heat resistant resin adhesive - Google Patents

Description

The present invention relates to (a) a high molecular weight aromatic polyimide having no unsaturated group at the terminal, and (b) terminal modification having an unsaturated group at the terminal. The imide oligomer, the (c) epoxy compound, and, if necessary, the (d) bismaleimide-triazine resin are related to a heat-resistant resin adhesive containing a resin composition in a specific composition ratio.

The heat-resistant resin adhesive of the present invention can bond various metal foils such as copper foil and heat-resistant support materials (for example, heat-resistant film, inorganic sheet) at a relatively low temperature and In a laminate laminated with a flexible resin adhesive, the adhesive layer has sufficient adhesive strength and excellent heat resistance, so for example, flexible wiring boards, copper clad boards for TAB (Tape Automated Bonding), etc. If used in the production of, each substrate obtained using the heat-resistant adhesive can be safely subjected to various high-temperature treatment steps such as subsequent solder treatment, improving the quality of the final product, The defective rate can be reduced.

[Description of Prior Art]

Conventionally, a flexible wiring board is often manufactured by bonding an aromatic polyimide film and a copper foil together using an adhesive such as an epoxy resin or a urethane resin.

However, a flexible wiring board manufactured using a known adhesive has a problem that when exposed to high temperature in the subsequent soldering process, it causes blistering or peeling in the adhesive layer, and the heat resistance of the adhesive is high. Was desired.

As a heat-resistant adhesive, an imide resin adhesive has been proposed, for example, N, N '-(4,4'-diphenylmethane).
A precondensate composed of bismaleimide and 4,4'-diaminodiphenylmethane is known. However, since the precondensate itself is brittle, it is not suitable as an adhesive for a flexible circuit board.

As a method for improving the above-mentioned drawbacks, an adhesive film (dry film) is formed from a resin composition obtained by mixing an aromatic polyimide obtained from benzophenonetetracarboxylic acid and an aromatic diamine and polybismaleimide, and its adhesiveness A method has been proposed in which a film is sandwiched between a heat resistant film such as a polyimide film and a copper foil and thermocompression bonded. (JP-A-62-232475 and JP-A-62-232475
However, the softening point of the adhesive film is 180 ° or more, and the adhesion between the polyimide film and the copper foil is about 26
At a high temperature of 0 to 280 ℃, and about 30 to 60kg / cm ²
It is necessary to perform under a high pressure, and under such adhesion conditions, using an organic resin pressure roll continuously,
It is extremely difficult to laminate the polyimide film and the copper foil, which is a problem in terms of practicality.

[Problems to be solved by the present invention]

An object of the present invention is to provide a heat-resistant resin adhesive having a low softening temperature, in which the above-mentioned problems in the known adhesion have been solved, and a heat-resistant film and various metal foils can be suitably laminated. The purpose is.

[Means for solving the problem]

This invention relates to (a) a soluble and high molecular weight aromatic polyimide obtained from a tetracarboxylic acid component containing 60 mol% or more of 2,3,3 ', 4'-biphenyltetracarboxylic acid and an aromatic diamine component. 100 parts by weight of (b) an aromatic tetracarboxylic acid component, a diamine component, and a monoamine or dicarboxylic acid component having an unsaturated group are reacted to obtain a terminal-modified imide oligomer having a softening point of 300 ° C. or lower. 50-600 parts by weight, preferably 60-500 parts by weight,
(C) Epoxy compound having an epoxy group 10 to 200 parts by weight, preferably 20 to 150 parts by weight, and (d) bismaleimide-triazine resin 0 to 100 parts by weight, preferably 0 to 80 parts by weight are resin components. And a heat-resistant resin adhesive.

In the present invention, the soluble and high molecular weight aromatic polyimide used as the resin component is, for example, 2,3,3 ′,
The amount of 4'-biphenyltetracarboxylic acid is about 60 mol% or more, preferably 80 mol% or more, particularly preferably 90 to 100 mol%.
Using a tetracarboxylic acid component and an aromatic diamine, which are contained in an amount of about 1 mol%, as a monomer component in approximately equimolar amounts, a phenol solvent, an amide solvent, a solvent of a compound having a sulfur atom, a glycol solvent, an alkylurea solvent are used. Both monomer components are polymerized and imidized at a high temperature (particularly at a temperature of 140 ° C. or higher) in an organic polar solvent such as a solvent, and the aromatic compound does not have an unsaturated group at its end. Group I polyimide, and the logarithmic viscosity corresponding to the degree of polymerization of the polymer (measured concentration; 0.5 g / 100 ml solvent,
Solvent; N-methyl-2-pyrrolidone, measurement temperature; 30 ° C)
0.1 to 7, particularly 0.2 to 6 and more preferably 0.3 to 5
It is a relatively high molecular weight polymer,
Any of the above organic polar solvents (especially amide solvents)
A soluble aromatic polyimide that can be uniformly dissolved at a concentration of at least 3% by weight, particularly about 5 to 40% by weight is preferable.

Further, as the method for producing the high molecular weight aromatic polyimide, the tetracarboxylic acid component and the aromatic diamine component are polymerized in an organic polar solvent at a low temperature of 0 to 80 ° C.,
High molecular weight obtained (logarithmic viscosity of at least 0.1)
Of the aromatic polyamic acid, and the polyamic acid may be imidized by any known method to produce a soluble aromatic polyimide.

In other words, the above-mentioned high molecular weight aromatic polyimide has the general formula I (However, in the general formula I, Ar is a divalent residue excluding the two amino groups of the aromatic diamine), at least 60 mol%, particularly 80 mol% or more, A high molecular weight (90 to 100 mol%), which is soluble in an organic polar solvent as described above (dissolves at 3% by weight or more at 25 ° C.) and has no unsaturated groups at both ends ( It is preferably an aromatic polyimide having a logarithmic viscosity of 0.3 to 5, especially 0.35 to 4.

The aromatic polyimide has an imidization ratio measured by infrared absorption spectrum analysis of 90% or more, particularly 95% or more, or the absorption peak related to the amide-acid bond of the polymer in infrared absorption spectrum analysis is substantially It is preferable that the imidization ratio is high so that only the absorption peak related to the imide ring bond is not found.

The above 2,3,3 ', 4'-biphenyltetracarboxylic acids are 2,3,3', 4'-biphenyltetracarboxylic acid, its dianhydride, or its lower alkyl ester compound, halogen. Compounds, especially 2,
3,3 ', 4'-biphenyltetracarboxylic dianhydride (a
-BPDA) is preferred.

In the heat-resistant resin adhesive of the present invention, the aromatic polyimide is an aromatic polyimide produced by using tetracarboxylic acids other than 2,3,3 ′, 4′-biphenyltetracarboxylic acid as a main component. Group I polyimides are not suitable because they are poorly soluble in organic polar solvents and have low compatibility with the terminal-modified imide oligomer.

As the tetracarboxylic acid component that can be used together with a-BPDA, etc., as the tetracarboxylic acid component used in the production of the high molecular weight aromatic polyimide,
For example, 3,3 ′, 4,4′-biphenylteracarboxylic acid, 3,
3 ', 4,4'-benzophenone tetracarboxylic acid, 3,3',
4,4'-diphenyl ether tetracarboxylic acid, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,
Preferred examples thereof include 4-dicarboxyphenyl) propane, pyromellitic acid, or acid dianhydrides or esterified products thereof.

Examples of the aromatic diamine component used for producing the high molecular weight aromatic polyimide include (a) a biphenyl-based diamine compound, a diphenylether-based diamine compound, a benzophenone-based diamine compound, a diphenylsulfone-based diamine compound, a diphenylmethane-based compound, Diphenylalkane-based diamino compound such as 2,2-bis (phenyl) propane, 2,2-bis (phenyl) hexafluoropropane-based diamine compound, diphenylene sulfone-based diamine compound, (b) di (phenoxy) benzene-based diamine Compound,
Di (phenyl) benzene-based diamine compound, (c) Di (phenoxyphenyl) hexafluoropropane-based diamine compound, Di (phenoxyphenyl) propane-based diamine compound, Di (phenoxyphenyl)
Aromatic diamines mainly containing "aromatic diamine compounds having two or more aromatic rings (benzene rings and the like), particularly 2 to 5" such as sulfone-based diamine compounds can be mentioned, and they may be used alone or It can be used as a mixture.

As the aromatic diamine component, particularly, diphenyl ether-based diamine compounds such as 1,4-diaminodiphenyl ether and 1,3-diaminodiphenyl ether, 1,
3-di (4-aminophenoxy) benzene, 1,4-di (4
-Aminophenoxy) benzene and other di (phenoxy)
Benzene-based diamine compound, 2,2-di [4- (4-aminophenoxy) phenyl] propane, 2,2-di [4-
A di (phenoxyphenyl) propane-based diamine-based compound such as (3-aminophenoxy) phenyl] propane,
"Has 2 to 4 aromatic rings such as di (phenoxyphenyl) sulfone-based diamine compounds such as bis [4- (4-aminophenoxy) phenyl] sulfone and bis [4- (3-aminophenoxy) phenyl] sulfone. Aromatic diamines containing mainly (90 mol% or more) "aromatic diamine compound" can be preferably mentioned.

The terminal-modified imide oligomer used in the heat-resistant resin adhesive of the present invention includes, for example, an aromatic tetracarboxylic acid component, a diamine component, and a monoamine or dicarboxylic acid component having an unsaturated group in each component. The total amount of the acid anhydride groups (or a pair of adjacent carboxyl groups) and the total amount of the amine groups are adjusted to be substantially equal and used, and first, the aromatic tetracarboxylic acid component and the diamine component, The reaction is carried out in an organic polar solvent at a temperature of 100 ° C. or lower, particularly 0 to 60 ° C. to form an “amide-acid bond-containing oligomer”, and then the amic acid oligomer and a monoamine or dicarboxylic acid having an unsaturated group are formed. Obtained by reacting the components and heating to an elevated temperature of 140-250 ° C.

The terminal-modified imide oligomer has a softening point of 300.
℃ or less, particularly 40 ~ 250 ℃, more preferably 50 ~ 230 ℃, the same logarithmic viscosity as described above 0.5 or less, particularly 0.01 ~.
A low molecular weight oligomer having a molecular weight of 0.4, more preferably about 0.01 to 0.3, and having a terminal unsaturated group and having an imide bond in the molecule is preferable.

In other words, the terminal-modified imide oligomer is represented by the general formula II or III. (In the general formulas II and III, Ar ₁ is a tetravalent aromatic residue obtained by removing four carboxyl groups of an aromatic tetracarboxylic acid compound, and Ar ₂ is obtained by removing two amino groups of a diamine compound. R ₁ is a divalent organic residue, R ₁ is a monovalent organic residue obtained by removing one amino group of a monoamine compound having an unsaturated group, and R ₂ is a dicarboxylic acid having an unsaturated group. A divalent organic residue having two carboxyl groups removed, wherein m and n are 1 to 50, particularly 1
It is an integer of about 30. It is preferable that it is the terminal modification imide oligomer shown by these.

The above-mentioned terminal-modified imide oligomer has a high imidization ratio such that in the infrared absorption spectrum analysis, an absorption peak related to the amide-acid bond of the oligomer is not substantially found and only an absorption peak related to the imide ring bond is observed. Preferably there is.

The "aromatic tetracarboxylic acid component" and "diamine component" used in the production of the terminal-modified imide oligomer are various aromatic tetracarboxylic acids already exemplified in the method for producing a high molecular weight aromatic polyimide. It is possible to use any of the aromatic diamine compounds.

In the production of the terminal-modified imide oligomer, as the aromatic tetracarboxylic acid component, especially 2,3,3 ', 4'-biphenyltetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, Or, an aromatic tetracarboxylic acid component containing a biphenyltetracarboxylic acid such as an acid dianhydride or an esterified product of these acids as a main component (80 mol% or more, particularly 90 mol% or more) Preferred and benzophenone tetracarboxylic acids, biphenyl ether tetracarboxylic acids, bis (3,4-dicarboxyphenyl) benzenes, 2,2-bis (3,4-dicarboxyphenyl) propanes, pyromellitic acids It is also possible to use an aromatic tetracarboxylic acid component containing mainly such as, and further, biphenyltetracarboxylic acids and the other aromatics mentioned above. Tiger and carboxylic acids may be is combined aromatic tetracarboxylic acid component.

In the production of the terminal-modified imide oligomer, as the diamine component, in particular, diphenyl ether-based diamine compound, diphenyl sulfone-based diamine compound, diphenylalkane-based diamine compound, biphenyl-based diamine compound, di (phenoxyphenyl) propane-based diamine compound, di (phenoxy) ) "Aromatic diamine compounds having 2 to 4 benzene rings" such as benzene-based diamine compounds
Diamine component mainly containing, or 1,3
A diamine component mainly containing "aliphatic diamine compounds" such as diamino-2-hydroxypropane, diaminoethane, diaminopropane, diaminobutane, diaminopentane, and the above aromatic diamine compounds and aliphatic diamine compounds in combination Any diamine component can be used.

Further, in the production of the terminal-modified imide oligomer, as a monoamine compound having an unsaturated group, (a) propargylamine, 3-aminobutyne, 4-aminobutyne, 4-aminopentine, 5-aminopentine, 6-aminohexyne, 7-aminohepsin, 4- "Aliphatic monoamine compound having unsaturated group" such as amino-3-methylbutyne and allylamine, or (b) m-
Or p-aminostyrene, m-amino-α-methylstyrene, 1-isopropenyl-3- (2-aminoisopropyl) benzene, 3-aminophenylacetylene, 4
“Aromatic monoamine compound having unsaturated group” such as aminophenylacetylene can be mentioned.

Examples of the dicarboxylic acid compound having an unsaturated group include (a) maleic acid, citraconic acid, their acid anhydrides,
(B) Nadic acid, its acid anhydride, its acid ester, etc., (c) Itaconic acid, its acid anhydride, its acid ester, etc., (d) Tetrahydrophthalic acid, its acid, etc. Preferable examples are "unsaturated dicarboxylic acids having adjacent two carboxy" such as anhydrides and acid esterified products thereof.

As the organic polar solvent used in the production of the terminal modified imide oligomer, the same solvent as the organic polar solvent used in the production of the high molecular weight aromatic polyimide can be used, for example, N, N-dimethylacetamide, N, N-
Diethyl acetamide, N, N-dimethylformamide,
N, N-diethylformamide, N-methyl-2-pyrrolidone and other amide solvents, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, hexamethyl sulfolamide and other sulfur atom-containing solvents, cresol, phenol, Phenolic solvents such as xylenol, solvents having oxygen atoms in the molecule such as acetone, methanol, ethanol, ethylene glycol, dioxane, tetrahydrofuran, pyridine,
Other solvents such as tetramethylurea can be mentioned, and further, if necessary, aromatic hydrocarbon solvents such as benzene, toluene and xylene, other types of organic solvents such as solvent naphtha and benzonitrile. It is also possible to use together.

Examples of the epoxy compound having an epoxy group used in the heat resistant resin adhesive of the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin. Examples thereof include "epoxy compounds having one or more epoxy groups" such as epoxy resins and glycidyl amine type epoxy resins, and a plurality of the above various epoxy resins can be used in combination. In this invention, the epoxy compound is
Those having a melting point of 90 ° C. or lower, particularly about 0 to 80 ° C., or those which are liquid at a temperature of 30 ° C. or lower are particularly preferable.

Further, in the heat-resistant resin adhesive of the present invention, a small amount of the above-mentioned suitable curing agent for epoxy resin, curing accelerator and the like may be added.

As the curing agent and curing accelerator for the epoxy resin,
Examples thereof include imidazoles, tertiary amines, triphenylphosphines, dicyandiamides, hydrazines, aromatic diamines and organic peroxides.

The bismaleimide-triazine resin used in the heat-resistant resin adhesive of the present invention is an already known thermosetting resin composition, for example, a bismaleimide component and a triazine monomer having a cyanate group or a prepolymer component. Which is a thermosetting resin having an imide group and a triazine ring, which may be modified by 0 to 30% by weight with acrylic acid esters, divinylbenzene, styrene, triallyisocyanate, etc. Suitable examples thereof include "BT Resin" manufactured by Kagaku Co., Ltd.

The heat-resistant resin adhesive of the present invention is a resin component having a specific composition ratio consisting of the above-mentioned high molecular weight aromatic polyimide, an end-modified imide oligomer, an epoxy compound, and, if necessary, a bismaleimide-triazine resin. Is a heat-resistant resin adhesive which is contained as a main component (particularly preferably 90% by weight or more, and more preferably about 95 to 100% by weight). In the solvent, especially 3 to 50% by weight, more preferably 5 to
It may be a solution composition of a heat-resistant resin adhesive that is uniformly dissolved at a concentration of 40% by weight. The solvent composition of the heat resistant resin adhesive has a solution viscosity (30 ° C) of 0.1 to 200
It is preferably 00 poise, particularly about 0.2 to 1000 poise.

The heat-resistant resin adhesive of the present invention has a softening point of a composition containing only an uncured resin component (the temperature at which softening starts on a hot plate) is 180 ° C or lower, particularly 50 to 170 ° C or lower, and more preferably Is preferably about 60 to 160 ° C.

The heat resistant resin adhesive of the present invention is preferably one that can be thermoset by heating to a curing temperature of 130 to 400 ° C, more preferably 140 to 350 ° C.

The heat-resistant resin adhesive of the present invention may contain, as a resin component, other thermosetting resin such as phenol resin in a small proportion.

As the organic polar solvent used in preparing the solution composition of the heat-resistant resin adhesive, the organic polar solvent used in the production of the terminal-modified imide oligomer can be used as it is, for example, dioxane. An organic polar solvent having an oxygen atom in the molecule, such as tetrahydrofuran, can be preferably used.

The heat-resistant resin adhesive of the present invention is a solution composition of a heat-resistant adhesive in which all of the above resin components are uniformly dissolved in an organic polar solvent, and a heat-resistant adhesive such as a suitable metal foil or aromatic polyimide film. Coating on the surface of a flexible film or a film of a thermoplastic resin such as polyester or polyethylene, and the coating layer is at a temperature of 60 to 140 ° C, particularly 80 to 130 ° C, for 20 seconds to 100 minutes, and particularly 30 to 60 By drying for a minute, the solvent was substantially removed (preferably the residual solvent ratio was 1% by weight or less, particularly 0.5% by weight or less). 1 to 150 μm
A dry film or sheet) can be formed.

In order to form a laminate such as a copper clad substrate by joining a heat resistant film and a metal foil using the heat resistant resin adhesive of the present invention, for example, heat resistance on a thin film formed as described above is used. Heat-resistant film and metal foil are laminated (bonded) at a temperature of 90 to 190 ° C, especially 100 to 180 ° C via a resin adhesive, and the laminated product is further heated to 80 to 350 ° C. 30 minutes to 40 hours at temperature, especially 1 to 3
By heating for 0 hours to heat and cure the heat-resistant adhesive layer, the above-mentioned laminate can be easily and continuously manufactured without any trouble.

The heat-resistant resin adhesive of the present invention is used to bond a heat-resistant film such as an aromatic polyimide film, a polyamide film, a polyether ether ketone, a PEEK film or a polyether sulfone film, and a suitable metal foil such as a copper foil. It can be used preferably.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.

In the following examples, the logarithmic viscosity (η _inh ) is the resin component concentration of 0.5 g / 100 ml of the solvent, aromatic polyimide or imide oligomer, N-methyl-2-pyrrolidone uniformly dissolved in the resin The values are calculated by preparing a solution, measuring the solution viscosity of the solution and the solution viscosity of only the solvent at 30 ° C., and using the following calculation formula.

The adhesive strength is a result of a T-type peel test performed at a peel speed of 50 mm / min using a tensile tester manufactured by Intesco Corporation.

Example 1 [Production of terminal modified imide oligomer A] In a glass flask having a capacity of 500 ml, (a) 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) 14.71 g (0.05 mol) ) (B) 1,3-di (4-aminophenoxy) benzene (TPE
-R) 29.23 g (0.1 mol) (c) Dimethylacetamide (DMAc) 175.76 g was charged and stirred in a nitrogen stream at 50 ° C for 1 hour to form an amic acid oligomer. The temperature was raised to 0 ° C., and the mixture was stirred at that temperature for 3 hours to generate an imide oligomer having an amino group at the terminal.

After cooling the reaction solution to 30 ° C., 11.77 g (0.12 mol) of maleic anhydride (MA) and 35 g of xylene were added, and the reaction solution was heated to 160 ° C. while removing xylene along with water. After stirring for 4 hours, an imide oligomer having an unsaturated group at the end is formed, and finally, the reaction solution is cooled to 20 ° C. and then poured into water to precipitate a powdery imide oligomer, and the precipitated imide The oligomer powder was separated by filtration, washed twice with methanol at 25 ° C., and dried under reduced pressure to produce a terminal-modified imide oligomer A.

This terminal-modified imide oligomer A has an imidization ratio of 95.
% Or more, and its inherent viscosity was 0.04.

[Production of terminal modified imide oligomer B]

In a glass flask having a capacity of 500 ml, (a) 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) 14.71 g (0.05 mol) (b) bis [4- (4-amino) Phenoxy) phenyl]
Sulfone (BAPS) 43.25 g (0.1 mol) (c) Dimethylacetamide (DMAc) 175.76 g was charged, and the mixture was stirred in a nitrogen stream at 50 ° C for 1 hour to generate an amic acid oligomer. The temperature was raised to 165 ° C., the mixture was stirred at that temperature for 3 hours to form an imide oligomer having an amino group at the terminal, and the reaction solution was cooled to 30 ° C., after which 11.77 g (0.12 mol) of maleic anhydride was prepared. And 35 g of xylene were added and reacted,
A terminal-modified imide oligomer B having an unsaturated group at the terminal was manufactured by the same manufacturing method as the above-mentioned “Process for manufacturing terminal-modified imide oligomer”.

This terminal-modified imide oligomer B has an imidization ratio of 95.
% And its logarithmic viscosity was 0.04.

[Production method of aromatic polyimide]

In a glass flask having a capacity of 500 ml, (a) 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) 29.42 g (0.1 mol) (b) 2,2-bis [4- (4-Aminophenoxy) phenyl] propane (BAPP) 41.07 g (0.1 mol) (c) N-methyl-2-pyrrolidone (NMP) 300 g was charged, and the mixture was stirred at 50 ° C. for 1 hour in a nitrogen stream to obtain polyamic acid. The reaction liquid was heated to about 195 ° C. and stirred at that temperature for 5 hours to form an aromatic polyimide.

The reaction solution is extruded into fibers at 20 ° C., and the fibers are formed by a wet spinning method in which the fibers are immersed in water at room temperature or below. The fibers are washed twice with methanol at 25 ° C. and then dried under reduced pressure to produce aromatics. A polyimide was produced.

The aromatic polyimide had an imidization ratio of 95% or more and an intrinsic viscosity of 0.41.

[Preparation of solution composition of heat-resistant adhesive]

In a glass flask having a capacity of 500 ml, 40 g of the above-mentioned terminal-modified imide oligomer A, 40 g of aromatic polyimide, epoxy resin (produced by Yuka Shell Epoxy Co., trade name; Epicoat 82
8) 20 g, curing agent: 2-methyl-4-methylimidazole 0.
3 g and 200 g of dioxane were charged and stirred at room temperature (25 ° C.) for about 2 hours to prepare a uniform heat-resistant resin adhesive solution composition (viscosity at 25 ° C .: 11 poise).

This solution composition maintained a uniform solution state even when left at room temperature for one week.

[Production of laminate using heat-resistant resin adhesive]

A solution composition of the above heat-resistant resin adhesive is applied on a polyimide film (Ube Industries, Ltd., trade name: UPILEX S type, thickness 75 μm) with a doctor blade to a thickness of 175 μm), and then Apply the coating layer at 60 ° C for 10 minutes.
It was heated at 0 ° C for 10 minutes and dried at 120 ° C for 10 minutes to form a heat-resistant resin adhesive layer (uncured and dried layer, softening point: 140 ° C) having a thickness of about 25 µm on the polyimide film.

The polyimide film having the heat-resistant resin adhesive layer and the copper foil (35 μm) are superposed on each other, and pressure-bonded between the laminate rolls heated to 180 ° C. while applying pressure. 2 hours at ℃ 2
A heat-resistant resin adhesive layer was cured by heat treatment at 00 ° C. for 2 hours, 220 ° C. for 1 hour, 240 ° C. for 1 hour, and further at 260 ° C. for 10 hours to produce a laminate.

The adhesive strength of the obtained laminate was measured, and the results are shown in Table 1.

Examples 2 to 6 Terminal-modified imide oligomer A or B prepared in Example 1 as shown in Table 1, epoxy resin [Epicoat manufactured by Yuka Shell Epoxy Co., Ltd.
828, Showa Kasei Co., Ltd. phenolic novolac resin (H-3), or Mitsubishi Gas Chemical Co., Ltd. (trade name; Tetrad-C)], Bismaleimide-triazine resin [Mitsubishi Gas Chemical Co., Ltd.] (Product name: BT resin BT-3309, viscosity at 50 ° C: 15
Poise, Tg after curing: 240 to 250 ° C.)] and used in an amount as shown in Table 1 "Terminal modified imide oligomer A or B, aromatic polyimide, epoxy compound, curing agent, and bismaleimide. -Triazine resin "was used, and a heat-resistant resin adhesive solution composition was prepared in the same manner as in Example 1.

A laminate was produced in the same manner as in Example 1 except that the solution composition of each heat-resistant resin adhesive produced as described above was used. The performance of the laminate is shown in Table 1.

Comparative Example 1 25 g of the terminal-modified imide oligomer A prepared in Example 1,
A resin solution composition was prepared using only 25 g of aromatic polyimide and 100 g of dioxane, and then the resin solution composition was applied onto a polyimide film in the same manner as in Example 1 except that the resin solution composition was used. Then, it was dried to form an adhesive layer (uncured and dried adhesive layer, thickness: 25 μm, softening point: 190 ° C.).

A polyimide film having an adhesive layer formed thereon and a copper foil were laminated, but it was substantially impossible.

Comparative Example 2 In addition to using 3,4,3 ′, 4′-benzophenone tetracarboxylic dianhydride as the tetracarboxylic acid component,
In the same manner as in Example 1, the aromatic polyimide (logarithmic viscosity:
0.5) was produced. During this production, precipitation of a particulate polymer was observed in the reaction liquid due to imidization.

A solution composition was prepared in the same manner as in Example 1 except that the aromatic polyimide prepared as described above was used, but the aromatic polyimide had low solubility in a 1,4-dioxane solvent. In addition, it also showed unsatisfactory compatibility with the terminal-modified imide oligomer A, and it was not possible to easily prepare a stable and uniform resin solution.

Therefore, using the solution composition described above, even if applied on a polyimide film and dried, it is not possible to form an adhesive layer having a uniform thickness, and further it is possible to produce a laminate. could not.

(Operation and effect of the present invention)

The heat-resistant adhesive of the present invention has flexibility and has a softening point of 180 ° C. or lower, and can continuously laminate various metal foils and heat-resistant films, By heat-curing at a temperature of about 180 to 400 ° C., it is possible to continuously produce a laminated body having a high level of adhesive strength and bonded through a flexible adhesive layer having excellent heat resistance. You can do it.

Further, the heat-resistant adhesive of the present invention is heat-resistant (excellent in adhesiveness at a temperature of 150 ° C. or higher even after being applied on a supporting film from a solution composition of the heat-resistant adhesive, dried, and cured by heating. Since it has excellent flexibility, it can be suitably used as an adhesive for flexible wiring boards, copper-clad boards for TAB, etc.

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Claims (1)

(57) [Claims] 1. A soluble and high molecular weight aromatic compound obtained from (a) a tetracarboxylic acid component containing 2,3,3 ', 4'-biphenyltetracarboxylic acids in an amount of 60 mol% or more and an aromatic diamine component. 100 parts by weight of polyimide, (b) an end-modified imide having a softening point of 300 ° C. or lower obtained by reacting an aromatic tetracarboxylic acid component, a diamine component, and a monoamine or dicarboxylic acid component having an unsaturated group 50 to 600 parts by weight of an oligomer, (c) 10 to 200 parts by weight of an epoxy compound having an epoxy group, and (d) 0 to 100 parts by weight of a bismaleimide-triazine resin are contained as resin components. Heat resistant resin adhesive.