JPS61143477A - Heat-resistant adhesive - Google Patents

Abstract

PURPOSE:To provide a heat-resistant adhesive consisting of polyamic acid and polyimic acid having specific recurring units, and capable of keeping the heat- resistance and adhesivity even at a high temperature. CONSTITUTION:The objective adhesive is composed of a polymer having the recurring unit of formula I [Y is group of formula II or III; R is >=3C (cyclo) aliphatic group, (condensed polycyclic) aromatic group, or mutually connected non-condensed polycyclic aromatic groups]. The polymer wherein Y is group of formula II can be prepared by reacting (A) 1,3-bis(3-aminophenoxy)benzene with (B) the compound of formula IV (e.g. 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride) in an organic solvent [e.g. bis(2-methoxyethyl) ether] preferably at <=50 deg.C for 4-24hr, and the product can be converted to another polymer wherein Y is group of formula III by thermally dehydrating e.g. at 100-300 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-resistant adhesive, and particularly to an adhesive that has strong adhesive strength and excellent heat resistance.

[Conventional technology]

Conventionally, adhesives made of various organic synthetic polymers have been known, and adhesives such as polybenzimidazole adhesives and polyimide adhesives have been developed as adhesives having excellent heat resistance. In addition to the above-mentioned adhesives, adhesives for polyimide films, which are particularly heat-resistant films, include fluororesins, polyamideimides, silicones, epoxy acrylics, nitrile rubbers, phenols, and polyesters. Adhesives have been developed, but those that are satisfactory in terms of heat resistance have inferior adhesive strength, while those that have excellent adhesive strength have poor heat resistance. It's not a thing.

A heat-resistant adhesive that is excellent in both heat resistance and adhesive strength is the polyimide adhesive developed by D. J. Progar et al. (U.S. Pat. No. 4,065,345).
No.) is only known.

[Problem that the invention seeks to solve]

An object of the present invention is to obtain a new heat-resistant adhesive that has heat resistance that does not reduce adhesive strength during and after use, even when used at high temperatures, and has stronger adhesive strength.

[Means for solving problems]

The present inventors have conducted extensive research to achieve the above object and have completed the present invention.

That is, the heat-resistant adhesive of the present invention has the following formula: (I) R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, an aromatic group represents a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups interconnected directly or through a bridge member. ) It is a heat-resistant adhesive made of a polymer having a repeating unit represented by:

The heat-resistant adhesive of the present invention is a polymer having a repeating unit represented by the formula (I), that is, a polyamic acid and/or polyimide having a repeating unit represented by the formula (I).

The polymer that is the heat-resistant adhesive of the present invention uses 1,3-bis(3-aminophenoxy)benzene (hereinafter abbreviated as APB) as a diamine component, and one type of polymer is used as a diamine component. These are polyamic acids obtained by reacting the above tetracarboxylic dianhydrides and/or polyimides obtained by further cyclodehydration of the same.

As a polyimide using APB, APB, 3゜3゜4
．． Addition type polyimide with terminal acetylene produced from 4'-benzophenone tetracarboxylic dianhydride and 3-aminophenyl acetylene (manufactured by Gulf, trade name:
Thermid-600> is known. (U.S. Pat. Nos. 3,845,018 and 3,879,349) However, polycondensation type polyimide consisting of APB and tetracarboxylic dianhydride has not been known at all as an adhesive.

These polymers can usually be produced by reacting APB with a tetracarboxylic dianhydride in an organic solvent.

The tetracarboxylic dianhydride used in this method is (wherein R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group,
Represents a tetravalent group selected from the group consisting of a monocyclic aromatic group, a fused polycyclic aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. . ) is a tetracarphonic dianhydride represented by

That is, the tetracarboxylic dianhydride used is:
For example, ethylenetetracarboxylic dianhydride, cyclopencune carboxylic dianhydride, pyromellitic dianhydride,
3.3; 4.4'-benzophenonetetracarboxylic dianhydride, 2,2:3.3'-benzophenonetetracarboxylic dianhydride, 3.3-4.4'-biphenyltetracarboxylic dianhydride , 2,2:3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(
2,3-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenyl)-ternianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2 ,3-dicarboxyphenyl)
Ethani dianhydride, bis(2+ 3-dicarboxyphenyl)methani dianhydride, bis(3゜4-dicarboxyphenyl)methani dianhydride, 2,3゜6.7-naphthalenetetracarboxylic dianhydride, 1,4゜5.8-naphthalenetetracarboxylic dianhydride, 1.2゜5.6-naphthalenetetracarboxylic dianhydride, 1,2゜3.4-benzenetetracarboxylic dianhydride, 3,4,9゜10-perylenetetracarboxylic dianhydride, 2,3,6゜7-anthracenetetracarboxylic dianhydride, 1,2゜7.8
-phenanthrenetetracarboxylic dianhydride and the like.

These tetracarboxylic dianhydrides may be used alone or in combination.
It is used by mixing more than one species.

The polymer production reaction is usually carried out in an organic solvent. Examples of organic solvents used in this reaction include N-methyl-2
-pyrrolidone, N,N-dimethylacetamide, N,N
-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, N,N-diethylacetamide, N,N
-dimethylmethoxyacetamide, dimethylsulfoxide, pyridine, dimethylsulfone, hexamethylphosphoramide, tetramethylurea, N-methylcaprolactam, butyrolactam, tetrahydrofuran, m-dioxane, p-dioxane, 1,2-dimethoxyethane, bis(2 -methoxyethyl)ether, 1,2-bis(2
-methoxyethoxy)ethane, bis(2-(2-methoxyethoxy)ethyl)ether, and the like.

The reaction temperature is usually 60°C or lower, preferably 50°C or lower.

The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.

The reaction time varies depending on the tetracarboxylic dianhydride used, the type of solvent, and the reaction temperature.
The reaction is allowed to take a sufficient time to complete the production of the polyamic acid represented by II). Usually 4 to 24 hours is sufficient.

Through such a reaction, a polyamic acid having a repeating unit of the following formula (III) is obtained.

R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic group in which aromatic groups are interconnected directly or through a bridge member. The formula represents a tetravalent group selected from the group consisting of aromatic groups. ) Furthermore, by heating and dehydrating the obtained polyamic acid at 100 to 300°C, a corresponding polyimide having a repeating unit of the following formula (IV) is obtained.

R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic group in which aromatic groups are interconnected directly or through a bridge member. The formula represents a tetravalent group selected from the group consisting of aromatic groups. ) When the thus obtained polymer is used as an adhesive, (I) it is used as an adhesive solution mainly containing the polyamic acid represented by the above formula (III), and (2)
) Cases in which a polyimide represented by the above formula (IV) is mainly used.

In the case of fil, the adhesive solution mainly containing polyamic acid represented by the above formula (I[+) is a solution in which polyamic acid is dissolved in an organic solvent.
It may also be a reaction product liquid containing a polyamic acid obtained by reacting the dianhydride with the tetracarboxylic dianhydride. It may also contain polyimide, which is a cyclized product of polyamic acid, with polyamic acid as the main component.

Therefore, an adhesive solution containing polyamic acid is
It may also be a solution or suspension partially containing polyimide.

When using an adhesive containing such a polyamic acid, a thin layer of the polyamic acid adhesive is applied to the objects to be bonded, and the adhered objects are then heated in air for the required time of 220 minutes. Preheat to around °C to remove excess solvent.
The polyamic acid adhesive is converted to a more stable polyimide, then the pressure of 1-1000 kg/cnt, 50
By press-bonding at a temperature of ~400°C and curing at a temperature of 100~400°C, objects to be adhered can be firmly adhered.

In the case of (2), the polyimide represented by the above formula (IV) is the polyamic acid of the above formula (■) heated and dehydrated to form, for example, a film, or it is substantially the polyimide itself in the form of powder. . Further, it may contain a portion of the polyamic acid of the above formula (III).

When using substantially polyimide, a film or powder is inserted between the objects to be adhered, and a
The adhesive material can be firmly bonded by pressing at a pressure of kg/crA and a temperature of 50-400°C and curing at a temperature of 100-400'C.

〔Example〕

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

Example-1 In a container equipped with a stirrer, a reflux condenser, and a nitrogen introduction tube,
Loaded with 14.6 g (0.05 mol) of A P B and 92.1 g of bis(2-methoxyethyl) ether,
At room temperature and under nitrogen atmosphere, 16.1 g of 3.3',4.4'-henshiphenonetetracarboxylic dianhydride (
0.05 mol) was added in four portions while being careful not to increase the solution temperature, and the mixture was stirred at room temperature for about 20 hours. The intrinsic viscosity of the polyamic acid thus obtained at 35°C in N,N-dimethylacetamide solvent at a concentration of 0.5% was 1.23 Ll.
It was l/g. A cold rolled steel plate (JIS G314
1.5PCC/SD, 25 x 100 x 1.
6 mm) and heated at 100°C for 1 hour at 220°C.
After heating and drying for 1 hour, cold rolled steel plates were stacked and
The pressure was applied to 20 kg/cnl for 5 minutes at ℃.

The thickness of the applied adhesive was 30 microns.

The tensile shear adhesive strength of this product is 277 at room temperature for 6 seconds.
kg/clll, the measurement method is JIS
- according to 6848 and 6850. ). Add this 2 more times
155kg/cu when measured at a high temperature of 00℃
It was t.

Example-2 14.6g (0.05 mol) under nitrogen atmosphere
A P B of 76.58 N,N-dimethylace1-
Amylo was added, and while stirring, 10.9 g (0.05 mol) of pyromelli nodonic dianhydride was added little by little as a dry solid. During this time, the temperature inside the reactor was cooled to maintain a temperature of 25 to 30°C, and after addition of pyromelli nodoic dianhydride, stirring was continued at room temperature under a nitrogen atmosphere for about 20 hours. 35 of the polyamic acid thus obtained
The intrinsic viscosity at 0.5% concentration in °C1N,N-dimethylacetamide solvent was 1.10 dI/g. After casting the above polyamic acid solution on a glass plate,
, 200° C. and 300° C. for 1 hour each to obtain a pale yellow transparent polyimide film. This polyimide film was preheated to 130°C on a cold rolled steel plate (JIS
G3141.5PCC/SD, 25x 100X
1.6 fins) inserted between 20 kg/c at 340 °C
nl was pressurized for 5 minutes to crimp it. The tensile shear adhesive strength of this material at room temperature was 300+r/cut, and when this was further measured at a high temperature of 200°C, it was 18
It was 0 kg/cnt.

Example-3 14.6g (0.05 mol) under nitrogen atmosphere
of APB was added to 92.1 g of N,N-dimethylacetamide, and while stirring, 16.1 g of 3.3-4.4'-henzophenonetetracarboxylic dianhydride (
0.05 mol) was added in small portions as a dry solid. During this time, the reactor was cooled to maintain a temperature of 25 to 30°C, and 3.3-4.4'-henshiphenonetetracarboxylic dianhydride was added to the old barley for about 20 hours under a nitrogen atmosphere. Stirring was continued at room temperature. 3 of the polyamic acid thus obtained
5°C, in N,N-dimethyll1acetamitone container 0.
The intrinsic viscosity at 5% concentration is 0.73d! /g.

Using a polyimide film obtained from the above polyamic acid solution in the same manner as in Example-2, a cold rolled steel plate was crimped under the same conditions as in Example-2.

The tensile shear adhesive strength of this product at room temperature is 296k.
g/cnl. When this was further measured at a high temperature of 200°C, it was found to be 153 kg/-.

〔Effect of the invention〕

The present invention provides an adhesive that exhibits strong adhesive strength without reducing heat resistance, and can maintain high adhesive strength even at high temperatures.

Claims (1)

[Claims] Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic group in which aromatic groups are interconnected directly or through a bridge member. A heat-resistant adhesive made of a polymer having a repeating unit represented by the formula (representing a tetravalent group selected from the group consisting of aromatic groups).