JPH044282A - heat resistant adhesive - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable to copper-clad substrate for TAB, having excellent heat resistance and flexibility after heating and curing, comprising a highmolecular weight aromatic polyimide, a terminal modified imide oligomer and a bismaleimide-triazine resin in a specific ratio. CONSTITUTION:The objective adhesive comprising (A) 100 pts.wt. high-molecular weight aromatic polyimide consisting of a tetracarboxylic acid component containing >=60mol% 2,3,3',4'-biphenyltetracarboxylic acid and an aromatic diamine component, (B) 10-200 pts.wt. terminal modified imide oligomer prepared by reacting an aromatic tetracarboxylic acid component with a diamine component and an unsaturated group-containing monoamine or dicarboxylic acid component, having <=300 deg.C softening point and (C) 140-700 pts.wt. bismaleimide- triazine resin, as resin components.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention relates to (a) a high molecular weight aromatic polyimide having no unsaturated groups at its terminals, and (b) a terminal-modified polyimide having an unsaturated group at its terminals. The present invention relates to a heat-resistant adhesive containing an imide oligomer and (c) a bismaleimide-triazine resin as resin components in a specific composition ratio.

The heat-resistant adhesive of this invention can be used with various metal foils such as copper foil,
The laminate can be laminated with a heat-resistant support material (e.g., a heat-resistant film, an inorganic sheet, etc.) at a relatively low temperature, and the laminate laminated with the heat-resistant adhesive can be
The adhesive layer exhibits sufficient adhesion and also exhibits excellent heat resistance, so it can be used, for example, in flexible wiring boards, T'AB
(Tape Automated Bonding)
When used in the production of copper-clad boards for industrial use, each board obtained using the heat-resistant adhesive can be safely subjected to various high-temperature processing processes such as soldering.
It is possible to improve the quality of the final product and reduce the defective rate.

[Description of Prior Art] Conventionally, flexible wiring boards have often been manufactured by laminating an aromatic polyimide film and a copper foil together using an adhesive such as an epoxy resin or a urethane resin.

However, when flexible wiring boards manufactured using known adhesives are exposed to high temperatures during the subsequent soldering process, the adhesive layer may blister or peel. It was hoped that improvements would be made.

Imide resin adhesives have been proposed as heat-resistant adhesives; for example, a precondensate consisting of N,N'-(4,4'-diphenylmethane)bismaleimide and 4,4'-diaminodiphenylmethane is known. It is being However, this precondensate itself is unsuitable as an adhesive for flexible circuit boards due to its lameness.

As a method to improve the above-mentioned drawbacks, an adhesive film (dry film) is formed from a resin composition in which an aromatic polyimide obtained from benzophenone tetracarboxylic acid and an aromatic diamine is mixed with polybismaleimide, and its adhesive properties are improved. A method has been proposed in which a film is sandwiched between a heat-resistant film such as a polyimide film and copper foil and bonded by thermocompression. (See JP-A-62-232475 and JP-A-62-235382.) However, the above-mentioned adhesive film has a softening point of 180°C or higher,
Adhesion between polyimide film and copper foil is approximately 260 to 28
Approximately 30 to 60 kg/ under high temperature of around 0℃.
Under such bonding conditions, it is extremely difficult to continuously laminate polyimide film and copper foil using an organic resin pressure roll, making it impractical for practical use. The problem was gender.

[Problems to be Solved by the Present Invention] An object of the present invention is to solve the above-mentioned problems in the known adhesives, and to provide a softening temperature that enables suitable bonding of heat-resistant films and various metal foils. The purpose of this invention is to provide an adhesive with low heat resistance.

[Means for solving problems]

This invention provides (a) 100% by weight of a soluble, high molecular weight aromatic polyimide obtained from a tetracarboxylic acid component containing 60 mol% or more of 2.3+3',4'-biphenyltetracarboxylic acids and an aromatic diamine component. (b) A terminal-modified imide oligomer 10-10 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. 200 parts by weight, preferably 2
0 to 150 parts by weight, and (c) 140 to 700 parts by weight of bismaleimide-triazine resin, preferably 150 parts by weight.
The present invention relates to a heat-resistant adhesive characterized by containing ~600 parts by weight as a resin component.

In this invention, the soluble, high molecular weight aromatic polyimide used as the resin component is, for example, 2.3.3'
, 4'-biphenyltetracarboxylic acids about 60 mol%
or more, preferably 80 mol% or more, particularly preferably 90 mol% or more
A tetracarboxylic acid component containing ~100 mol% and an aromatic diamine are used in approximately equimolar amounts as a 1,000 molar component to produce phenolic solvents, amide solvents, solvents for compounds having sulfur atoms, glycol solvents, In an organic polar solvent such as an alkyl urea solvent, the Ametsumar component is mixed under high temperature (
It is an aromatic polyimide that does not have an unsaturated group at its terminal and is obtained by a manufacturing method of polymerization and imidization (particularly preferably at a temperature of 140°C or higher), and corresponds to the degree of polymerization of the polymer. Logarithmic viscosity (measured concentration; 0.
5g/100mjl! Solvent, solvent; N-methyl-2-pyrrolidone, measurement temperature: 30°C) is 0, 1 to 7, especially 0
．． It is a polymer with a fairly high molecular weight of about 2 to 6, more preferably about 0.3 to 5, and furthermore, at least 3% by weight, especially 5% by weight, of the above-mentioned organic polar solvent (especially amide solvent). A soluble aromatic polyimide that can be uniformly dissolved at a concentration of about 40% by weight is preferred.

Further, as a method for producing the above-mentioned high molecular weight aromatic polyimide, the above-mentioned tetracarboxylic acid component and aromatic diamine component are polymerized in an organic polar solvent at a low temperature of 0 to so'c. It is also possible to produce a soluble aromatic polyimide by producing an aromatic polyamic acid having a molecular weight (logarithmic viscosity of at least 0.1) and imidizing the polyamic acid by any known method.

Expressed in another way, the high molecular weight aromatic polyimide has the following formula: - Formula I (wherein - In Formula I, Ar is a divalent residue of an aromatic diamine excluding two amino groups. ) contains 60 mol % or more, particularly 80 mol % or more, more preferably 90 to 100 mol % of repeating units represented by ) and has a high molecular weight (having a logarithmic viscosity of 0.3 to 5, especially 0.35 to 4) and does not have unsaturated groups at both ends.
is preferably an aromatic polyimide.

The above-mentioned aromatic polyimide has an imidization rate of 90% or more, particularly 95% or more as measured by infrared absorption spectroscopy, or has an absorption peak related to the amide-acid bond of the polymer in infrared absorption spectroscopy. It is preferable that the imidization rate is so high that no absorption peaks are observed and only absorption peaks related to imide ring bonds are observed.

The above-mentioned 2.3.3',4'-biphenyltetracarboxylic acids include 2,3.3',4'-biphenyltetracarboxylic acid, its acid dianhydride, or its lower alkyl ester, halogen Among them, 2,3.3''14'-biphenyltetracarboxylic dianhydride (a-BPDA) is particularly suitable.

In the heat-resistant adhesive of the present invention, when the aromatic polyimide is produced mainly from tetracarboxylic acids other than 2,3.3",4"-biphenyltetracarboxylic acids, the aromatic polyimide This is not suitable because polyimide is poorly soluble in organic polar solvents and has low compatibility with the terminal-modified imide oligomer.

Examples of tetracarboxylic acid compounds that can be used together with a-BPDA and the like as the tetracarboxylic acid component used in the production of the above-mentioned high molecular weight aromatic polyimide include 3.3', 4.4'-biphenyl. Tetracarboxylic acid, 3.3', 4.4'-hensiphenotetracarboxylic acid, 3.3', 4.4°-diphenyl ether tetracarboxylic acid, bis(3,4-dicarboxyphenyl)methane, 2. Preferred examples include 2-bis(3,4-dicarboxyphenyl)propane, pyromellitic acid, and acid dianhydrides and esters thereof.

Examples of the aromatic diamine component used in the production of the above-mentioned high molecular weight aromatic polyimide include (a) biphenyl diamine compounds, diphenyl ether diamine compounds, benzophenone diamine compounds, diphenylsulfone diamine compounds, diphenylmethane diamine compounds, 2
．． Diphenylalkane diamine compounds such as 2-bis(phenyl)propane, 2,2-bis(phenyl)hexafluoropropane diamine compounds, diphenylene sulfone diamine compounds, (b) di(phenoxy)benzene diamine compounds , di(phenyl)benzene diamine compound, (c)
Di(phenoxyphenyl)hexafluoropropane-based diamine compounds, di(phenoxyphenyl)propane-based diamine compounds, di(phenoxyphenyl)sulfone-based diamine compounds, etc. with two or more aromatic rings (benzene rings, etc.), In particular, aromatic diamines mainly containing "aromatic diamine compounds having 2 to 5 atoms" can be mentioned, and they can be used alone or as a mixture.

Examples of the aromatic diamine component include diphenyl ether-based cyamine compounds such as 1,4-diaminodiphenyl ether and 1,3-diaminodiphenyl ether;
, 3-di(4-aminophenoxy)benzene, 1,4-
Di(phenoxy)benzene diamine compounds such as di(4-aminophenoxy)benzene, 2.2-bis(4-
aminophenoxyphenyl)propane, 2,2-bis(
Di(phenoxyphenyl)propane-based diamine compounds such as 3-aminophenoxyphenyl)propane, bis(4-(4-aminophenoxy)phenyl)sulfone,
Contains mainly (90 mol% or more) an aromatic diamine compound J having 2 to 4 r aromatic rings, such as a di(phenoxyphenyl)sulfonic diamine compound such as bis(4-(3-aminophenoxy)phenyl)sulfone. Preferred examples include aromatic diamine components.

The terminal-modified imide oligomer used in the heat-resistant adhesive of the present invention is, for example, an aromatic tetracarboxylic acid component, a diamine component, and a monoamine or dicarboxylic acid component having an unsaturated group. Anhydride group (
First, the aromatic tetracarboxylic acid component and the diamine component are mixed in an organic polar solvent by adjusting the equivalent weight so that the total amount of the amine groups (or a pair of adjacent carboxyl groups) and the total amount of the amine groups are approximately equal. and below 100°C, especially 0
React at a temperature of ~60°C to produce an oligomer J having an r amide-acid bond, then react the amic acid oligomer with a monoamine or dicarboxylic acid compound having an unsaturated group, and then react at a temperature of 140~ 250°
Any material may be used as long as it can be obtained by a manufacturing method in which C is heated to a high temperature. The terminal-modified imide oligomer has a softening point of 300°C or lower, particularly 40 to 250'C1, more preferably 50 to 230'C, and a logarithmic viscosity of 0.5 or lower, particularly 0. It is an oligomer with a low molecular weight of about .01 to 0.4, more preferably about 0.01 to 0.3, and has an unsaturated group at the end and an imide bond in the molecule. preferable.

In other words, the above-mentioned terminal-modified imide oligomer is a general 2 or Arz is a divalent residue obtained by removing two amino groups of a diamine compound, and R1 is a monovalent residue obtained by removing one amino group of a monoamine compound having an unsaturated group. is an organic residue, and R2 is a divalent organic residue obtained by removing two carboxyl groups of a dicarboxylic acid having an unsaturated group, and m and n are 1 to 5.
0, especially an integer of about 1 to 30. ) is preferably a terminal-modified imide oligomer.

The terminal-modified imide oligomer has such a high imidization rate that in infrared absorption spectroscopy, virtually no absorption peak related to the amide-acid bond of the oligomer is found, and only an absorption peak related to the imide ring bond is observed. It is preferable that there be.

The "aromatic tetracarboxylic acid component J" and the "diamine component" used in the manufacturing method number for the terminal-modified imide oligomer are various aromatic components already exemplified in the manufacturing method for high molecular weight aromatic polyimide. Both tetracarboxylic acids and aromatic diamine compounds can be used.

In the production of the terminal-modified imide oligomer, the aromatic tetracarboxylic acid component is particularly 2,3°3',4'
- Biphenyltetracarboxylic acids such as biphenyltetracarboxylic acid, 3.3', 4.4'biphenyltetracarboxylic acid, their dianhydrides, or esters of these acids are the main components (80 mole% or more,
In particular, aromatic tetracarboxylic acid components containing 90 mol% or more) are suitable, and include hensifhenonetetracarboxylic acids, biphenyl ether tetracarboxylic acids, bis(3,4-dicarboxyphenyl)henzea, Aromatic tetracarboxylic acid components mainly containing ゜2-bis(3,4-dicarboxyphenyl)propanes, pyromellitic acids, etc. can also be used, and further,
The aromatic tetracarboxylic acid component may be a combination of biphenyltetracarboxylic acids and the other aromatic tetracarboxylic acids mentioned above.

In the production of terminal-modified imide oligomers, the diamine component is particularly a diphenyl ether-based cyamine compound,
diphenylsulfone diamine compounds, diphenylalkane diamine compounds, hyphenyl diamine compounds,
Di(phenoxyphenyl)propane diamine compound,
A diamine component mainly containing an aromatic diamine compound having 2 to 4 r-Hensen rings such as a di(phenoxy)benzene-based diamine compound, or l.

A diamine component mainly containing "r-aliphatic diamine compounds such as 3-diamino-2-hydroxypropane, diaminoethane, diaminopropane, diaminobutane, and diaminopentane," further comprising the above-mentioned aromatic diamine compounds and aliphatic diamine compounds. Any diamine component used in combination may be used.

Furthermore, in the production of terminal-modified imide oligomers, (a) propargylamine, 3-aminobutyne, 4-aminobutyne, 4-aminopentyne, 5-aminopentyne, 6-aminohexine, 7-aminohexine, 4amino- 3-methylbutyne,
"Aliphatic monoamine compounds having an unsaturated group" such as allylamine, or (b) m- or P-aminostyrene, m-amino-α-methylstyrene, 1-isopropenyl-3-(2-aminoisopropyl)benzene, Examples include "aromatic monoamine compounds having an unsaturated group" such as 3-aminophenyl acetylene and 4-aminophenyl acetylene. .

In addition, as a dicarboxylic acid compound having an unsaturated group,
For example, (a) maleic acid, citraconic acid, their acid anhydrides,
These acid esters, etc., (b) nadic acid, its acid anhydrides, its acid esters, etc., (c) itaconic acid, its acid anhydrides, its acid esters, etc., (d) tetrahydrophthalic acid, its acids I of anhydrides, acid esters thereof, etc.
Preferred examples include "unsaturated dicarboxylic acids having r2 carboxy groups adjacent to each other."

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 high molecular weight aromatic polyimide can be used, such as N,N-dimethylacetamide, N,
N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methyl-2
- Amide solvents such as pyrrolidone, solvents containing sulfur atoms such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, and hexamethyl sulfolamide, phenolic solvents such as cresol, phenol, and xylenol, acetone, methanol,
Examples include solvents containing oxygen atoms in the molecule such as ethanol, ethylene glycol, dioxane, and tetrahydrofuran; other solvents such as pyridine and tetramethylurea; and, if necessary, aromatic solvents such as benzene, toluene, and xylene. It is also possible to use other types of organic solvents, such as group hydrocarbon solvents, solvent naphtha, and benzonitrile.

The bismaleimide-triazine resin used in the heat-resistant adhesive of the present invention is a known thermosetting resin composition, for example, composed of a bismaleimide component and a triazine monomer or prepolymer component having a cyanate group. The obtained thermosetting resin has an imide group and a triazine ring. Bismaleimide-triazine resin is
It may be modified with glycidyl esters, acrylic esters, divinylbenzene, styrene, triallyl isocyanate, etc. (particularly, ffBT resin manufactured by Mitsubishi Gas Chemical Co., Ltd.) can be preferably mentioned.

The heat-resistant adhesive of the present invention has a resin component as a main component (particularly preferably 90% Weight% or more,
More preferably, the heat-resistant adhesive contains 3 to 50% by weight, more preferably 5 to 50% by weight of the entire resin component in an appropriate organic polar solvent. The heat-resistant adhesive solution composition may be uniformly dissolved at a concentration of ~40% by weight. The heat-resistant adhesive solution composition preferably has a solution viscosity (at 30° C.) of about 0.1 to 20,000 poise, particularly about 0.1 to 1,000 poise.

The heat-resistant adhesive of the present invention has a softening point (temperature at which softening starts on a hot plate) of a composition containing only an uncured resin component of 150°C or lower, particularly 120°C or lower, and more preferably 30°C or lower. It is preferably about ~100°C, and
When the resin component is partially cured by heat treatment at about 100 to 200°C for 30 seconds to 100 minutes (those with a curing rate of 10 to 70% as described later), the softening point is higher than the softening point of the composition containing only the uncured resin component, and
0°C or less, especially 60 to 160°C, more preferably 80°C
The temperature is preferably about 150°C.

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

In addition, the heat-resistant adhesive of the present invention contains few other thermosetting resins such as phenol resin, curing agents and curing catalysts such as organic peroxides, imidazoles, and aromatic simians as resin components. It may be contained in a proportion.

The organic polar solvent used in preparing the heat-resistant adhesive solution composition can be the organic polar solvent used in the production of the terminal-modified imide oligomer, such as dioxane, tetrahydrofuran, etc. Organic polar solvents having an oxygen atom in the molecule can be suitably used.

The heat-resistant adhesive of the present invention is prepared by applying a heat-resistant adhesive solution composition in which all of the above-mentioned resin components are uniformly dissolved in an organic polar solvent to the surface of a heat-resistant film such as a suitable metal foil or aromatic polyimide film. Alternatively, it is applied onto the surface of a thermoplastic resin film such as polyester or polyethylene, and the coated layer is dried at a temperature of 60 to 140°C, especially 80 to 130°C, for 20 seconds to 100 minutes, especially 30 to 60 minutes. A thin film (with a thickness of approximately 1% by weight) of an uncured heat-resistant adhesive from which the solvent has been substantially removed by
~2001 Jm) can be formed.

The thin film of uncured heat-resistant adhesive produced as described above has suitable flexibility, and can be wrapped around paper tubes, etc., and can also be processed by punching holes. Furthermore, for example, a laminated sheet in which a thin layer of uncured heat-resistant adhesive is formed on the heat-resistant or thermoplastic film, and a metal foil or heat-resistant film for the transfer destination are superimposed. about 40 to 140°C1 especially 50 to
It is also possible to transfer the image onto a metal foil or heat-resistant film for the transfer destination by passing it between a pair of rolls (laminate rolls) heated to a temperature of 130°C.

Further, the heat-resistant adhesive described above may have a thickness of 120 to 200
°C1 30 seconds to 100, especially at temperatures of 130 to 190 °C
After heat treatment for 1 to 60 minutes, the curing rate determined by DSC calorific value at a heating rate of rlo°C/min is approximately 10 to 75%, particularly 20 to 70%, more preferably 3
B-staging can be achieved by partial heat curing to 0 to 65%. Although the softening temperature of the B-staged heat-resistant adhesive is higher than that in the uncured state, it is maintained within a range of about 50 to 180°C, and maintains sufficient adhesive performance. It is.

In addition, in order to form a laminate such as a copper-clad board by bonding a heat-resistant film and a metal foil using the heat-resistant adhesive of the present invention, for example, as described above, a B-staged heat-resistant The heat-resistant film and the metal foil are laminated at a temperature of 90 to 190°C (particularly 100 to 180"C) using a thermoplastic adhesive, and then the laminated film is laminated at a temperature of 80 to 350"C. 30 minutes at temperature
By heating and curing the heat-resistant adhesive layer for 40 hours, particularly for 1 to 30 hours, the above-described laminate can be easily and continuously manufactured without any problems.

If the heat-resistant adhesive of the present invention is used without B-stage in the production of the above-mentioned laminate, the heat-resistant adhesive may flow out during the above-mentioned lamination, or the adhesive layer may become uneven. Furthermore, when the laminate is heated to a high temperature after lamination, the heat-resistant adhesive may flow out or the adhesive strength may decrease.

The heat-resistant adhesive of this invention is made of aromatic polyimide film, polyamide film, polyether ether ketone (
It can be suitably used to bond a heat-resistant film such as PEEK film or polyether sulfone film to a suitable metal foil such as copper foil.

〔Example〕

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

In the following examples, the logarithmic viscosity (ηinh) was calculated such that the resin component concentration was 0.5 g/100 mf solvent.
Aromatic polyimide or imide oligomer is uniformly dissolved in N-methyl-2-pyrrolidone to prepare a resin solution, and the solution viscosity of the solution and the solution viscosity of the solvent only are 30
The value was measured at °C and calculated using the formula below.

The adhesive strength was measured by performing a T-peel test using a tensile tester manufactured by Intesco at a peel rate of 50 openings/min.

Example 1 [Production of terminal-modified imide oligomer A] Volume 1500 mf
(a) 2.3.3′,4″-biphenyltetracarboxylic dianhydride (a-BPDA) in a glass flask.
14.71 g (0.05 mol) ■) 1.3-di(4
-aminophenoxy)benzene (TPE-R) 29.2
3g (0.1 mol) (c) Dimethylacetamide (D
175.76 g of MAc) was charged and stirred at 50°C for 1 hour in a nitrogen stream to produce an amic acid oligomer.Then, the reaction solution was heated to about 165°C.
The temperature was raised to C and stirred at that temperature for 3 hours to produce an imide oligomer having an amino group at the end.

After cooling the reaction solution to 50°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 to generate xylene. The reaction solution was stirred for 4 hours while removing water along with the unsaturated group to produce an imide oligomer having an unsaturated group at the end.Finally, the reaction solution was cooled to 20° and poured into water to form a powdery imide oligomer. After precipitating and filtering the precipitated imide oligomer powder, the temperature was set at 25°C.
The terminal-modified imide oligomer A was produced by washing twice with methanol and drying under reduced pressure.

This terminal-modified imide oligomer A has an imidization rate of 95
% or more, and its logarithmic viscosity was 0.04.

[Production of terminal-modified imide oligomer B] Capacity 500mf
! (a) 2,3.3',4''-
Biphenyltetracarboxylic dianhydride (a-BPDA)
14.71g (0.05 mol) (b) Bis(4-(4
-aminophenoxy)phenyl]sulfone (BAPS)
43.25 g (0.1 mol) (c) 175.76 g of dimethylacetamide (DMAc) was charged and stirred at 50°C for 1 hour in a nitrogen stream to produce an amic acid oligomer. 165°C
The reaction solution was heated to 50°C, stirred for 3 hours at that temperature to produce an imide oligomer having an amino group at the end, and after cooling the reaction solution to 50°C, maleic anhydride 11.
A terminal-modified imide oligomer B having an unsaturated group at the terminal was produced in the same manner as in the above-mentioned method for producing r-terminally modified imide oligomer A, except that 77 g (0.12 mol) and 35 g of xylene were added.

This terminal-modified imide oligomer B has an imidization rate of 95
% or more, and its logarithmic viscosity was 0.04.

[Production method of aromatic polyimide]

Capacity 500mf! (a) 2,3 in a glass flask
．． 3',4'-biphenyltetracarboxylic dianhydride (
a-BPDA) 29.42g (0.1 mol) (b)2
, 2-bisC4-(4-aminophenoxy)phenyl]propane (BAP P) 41.07 g (0,1
mole) (c) N-methyl-2-pyrrolidone (NMP)
300 g was charged and stirred for 1 hour at 50°C in a nitrogen stream to produce polyamic acid, and the reaction solution was heated to about 190°C and stirred at that temperature for 5 hours to produce aromatic polyimide. was generated.

The reaction solution was extruded into fibers at 20°C and then poured into water below room temperature to form fibers using a wet spinning method.The fibers were washed twice with methanol at 25°C and then dried under reduced pressure. An aromatic polyimide was produced.

The aromatic polyimide had an imidization rate of 95% or more and a logarithmic viscosity of 0.41.

[Preparation of heat-resistant adhesive solution composition]

Capacity 500m1! In a glass flask, 10 g of the above-mentioned terminal-modified imide oligomer A and 25 g of aromatic polyimide were added.
g, Bismaleimide-triazine resin (Mitsubishi Gas Chemical ■
Manufacturer, product name: BT Resin BT330 (viscosity at 30°C = 15 poise) 65g and dioxane 200g were stirred at room temperature (25°C) for about 2 hours to form a uniform heat-resistant adhesive solution composition (25°C). The viscosity of C: lO poise) was prepared.

This solution composition maintained a uniform solution state after being left at room temperature for one week.

[Manufacture of laminate using heat-resistant adhesive] The above-mentioned heat-resistant adhesive solution composition was applied onto a polyethylene terephthalate (PET) film (25 μm) with a doctor blade to a thickness of 175 μm), and then the coated layer was , 10 minutes at 60°C, 10 minutes at 100°C,
Heat and dry for 120°CIO minutes to form a heat-resistant adhesive layer with a thickness of about 25μm on the PET film (uncured dried layer, softening point: 55°C 1 bending test: no cracks in the adhesive layer) was formed.

On the surface of the heat-resistant adhesive layer formed on the PET film, a polyimide film (manufactured by Ube Industries, trade name: U
PILEX S type, 75 μm thick) are stacked together and the laminate is passed under pressure between laminator rolls heated to 80°C to transfer the heat-resistant adhesive layer from the PET film to the polyimide film. This was transferred to form a heat-resistant adhesive layer with a thickness of about 25 μm on the polyimide film.

17. Polyimide film with its heat-resistant adhesive layer
A heat-resistant adhesive layer (curing rate 3
5%, softening point: 100°C).

This B-staged polyimide film having a heat-resistant adhesive layer and copper foil (35 μm) were overlapped and
The laminate is crimped by passing it between laminating rolls heated to 0°C while applying pressure, and the laminate is heated to 180°C.
The heat-resistant adhesive layer was cured by heat treatment for 2 hours at °C, 2 hours at 200 °C, 1 hour at 220 °C, 1 hour at 240 °C, and 10 hours at 260 °C, and then laminated. manufactured a body.

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 produced in Example 1 as shown in Table 1, and bismaleimide-triazine resin [manufactured by Mitsubishi Gas Chemical Co., Ltd., product name: BTI, Zin (BT3109.30 'C(7) viscosity: 100 poise,
In addition, BT330 (viscosity at 9.3oC: 15 poise)] was used, and the amount of "terminally modified imide oligomer A or B, aromatic polyimide and bismaleimide-triazine resin (BT resin)" was used as shown in Table 1. A heat-resistant adhesive solution composition was prepared in the same manner as in Example 1, except that each of the following was used.

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

Comparative Example 1 10 g of terminal-modified imide oligomer A produced in Example 1
A resin solution composition was prepared using only 25 g of aromatic polyimide and 100 g of dioxane, and then PET was prepared in the same manner as in Example 1, except that the resin solution composition was used.
Applying the resin solution composition on the film and drying it,
Adhesive layer (uncured dried adhesive layer, thickness = 25μ
m, softening point: 190°C).

As a result of bending the PET film on which the adhesive layer described above was formed, many cranks were generated in the adhesive layer.

Furthermore, transfer to a polyimide film was carried out at 150°C in the same manner as in Example 1 except that the PET film on which the adhesive layer was formed was used, but the adhesive layer did not soften. The adhesive layer could not be transferred properly.

Therefore, it was also virtually impossible to laminate the polyimide film with the adhesive layer transferred thereto and the copper foil.

Comparative Example 2 As the tetracarboxylic acid component, 3,4.3', 4'-
An aromatic polyimide (logarithmic viscosity: 0.5) was produced in the same manner as in Example 1, except that benzophenone tetracarboxylic dianhydride was used. During this production, particulate polymer was observed to be precipitated in the reaction solution due to imidization.

An attempt was made to prepare a solution composition in the same manner as in Example 1, except that the aromatic polyimide produced as described above was used, but the aromatic polyimide had low solubility in the 1,4-dioxane solvent. It also showed unsatisfactory compatibility with the terminal-modified imide oligomer A, making it impossible to easily prepare a stable and uniform resin solution.

Therefore, even if the solution composition described above is applied onto a PET film and dried, it is not possible to form an adhesive layer of uniform thickness, and furthermore, the transfer and production of laminates cannot be performed. I couldn't even do that.

[Operations and Effects of the Present Invention] The heat-resistant adhesive of the second invention remains flexible even in an uncured state and even after being partially heat-cured to a curing rate of about 10 to 70% and B-staged. In addition to having sex, 18
It has a softening point of 0°C or less, and it is possible to continuously laminate various metal foils and heat-resistant films. It is possible to continuously produce a laminate bonded via a flexible adhesive layer that has adhesive strength and excellent heat resistance.

Furthermore, the heat-resistant adhesive of the present invention can easily form an uncured, thin heat-resistant adhesive layer by applying a solution composition of the heat-resistant adhesive onto a support film and drying it. Moreover, the thin heat-resistant adhesive layer on the support film has sufficient flexibility, and the thin heat-resistant adhesive layer on the support film does not cause any problems even when holes are processed. It is also possible to transfer onto other heat-resistant films at an appropriate temperature.

Furthermore, the heat-resistant adhesive of the present invention has excellent heat resistance (excellent adhesion at temperatures of 150°C or higher) and flexibility even after being heat-cured, so it can be used especially for flexible wiring. It can be suitably used as an adhesive for substrates, TAB copper-clad substrates, etc.

Patent applicant: Ube Industries Co., Ltd.

Claims (1)

[Scope of Claims] (a) A soluble, high-molecular-weight aroma obtained from a tetracarboxylic acid component containing 60 mol% or more of 2,3,3',4'-biphenyltetracarboxylic acids and an aromatic diamine component 100 parts by weight of group polyimide, (b) terminal modification having a softening point of 300°C or less, obtained by reacting an aromatic tetracarboxylic acid component, a diamine component, and a monoamine or dicarboxylic acid component having an unsaturated group. 10 to 200 parts by weight of imide oligomer, and (c) 140 to 700 parts of bismaleimide-triazine resin.
A heat-resistant adhesive characterized in that the weight part is contained as a resin component.