JPH0519577B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a strong heat-resistant resin having excellent light transmittance and having a hetero imide ring and a furan ring in the polymer main chain. It is. The purpose is that the cured resin imidized by the ring-closing process has excellent heat resistance, abrasion resistance, chemical resistance, electrical insulation, film-forming properties, flexibility, mechanical properties, etc. as a polyimide resin. We provide heat-resistant resins that are useful as materials for electronic devices, electrical insulating materials, coatings, adhesives, paints, molded products, laminates, fibers, and film materials, but especially for liquid crystal displays for electronic devices. An object of the present invention is to provide a heat-resistant resin useful as an alignment film for an element.

[Prior art]

Conventionally, heterocycles such as imide, imidazole, thiazole, oxazole,
It is well known that compounds containing oxadiazole, triazole, quinoxaline, thiadiazole, oxazinone, quinazoline, imidazopyrrolone, isoindoroquinazolone, etc. have excellent heat resistance. However, these known polymers have rigid polymer main chains, and when formed into films, films, or coatings, they have poor flexibility, flexibility, elongation, or adhesiveness. Therefore, when used as an alignment film for liquid crystal, for example, it cannot withstand rubbing work and cannot fully align the liquid crystal, making it unable to function as a display element. Furthermore, when these polymers are heated during curing, they become significantly colored, becoming brown or blackish brown. Therefore, for example, when used as an alignment film for liquid crystal, the liquid crystal display element becomes brownish.
The visual field becomes dark, the contrast decreases, and the device no longer functions as a display element. From this point of view, various studies have been made in the past in order to achieve a balance between heat resistance, flexibility, light color property, and adhesiveness, but it has generally been the case that when one is good, the other is bad.

[Purpose of the invention]

As a result of studies aimed at overcoming such drawbacks, the present invention uses 2,8-diaminodiphenylene oxide, 2,4-diaminotoluene, and 1,3-bis(3-aminopropyl) as diamine components. ) Tetramethyldisiloxane is also used as a tetracarboxylic dianhydride component, 3,3',4,
It was discovered that by using 4'-benzophenonetetracarboxylic dianhydride as an essential component, a heat-resistant resin with a good balance of heat resistance, flexibility, light color, and adhesiveness can be obtained. The invention has now been completed.

[Structure of the invention]

In the present invention, when reacting a diamine and a tetracarboxylic dianhydride to form an imide ring, 2,8-diaminodiphenylene oxide and 2,4-diaminotoluene are used as the diamine component,
1,3-bis(3-aminopropyl)tetramethyldisiloxane and 3,3',4,4'-benzophenonetetracarboxylic dianhydride as an essential component. This is a method for producing a heat-resistant resin, characterized in that it is used as a heat-resistant resin.

Among the diamines used in the present invention, the essential components are 2,8-diaminodiphenylene oxide,
2,4-diaminotoluene and 1,3-bis(3
-aminopropyl)tetramethyldisiloxane. One way to make 2,8-diaminodiphenylene oxide is shown in the following reaction formula.

Reference: University of Fukui Faculty of Engineering Research Report 16(2)238('
68) Of course, diamines other than those mentioned above can also be used. For example, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, benzidine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl methane, 4'-diaminodiphenyl sulfone, 3,
3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 2,6-diaminopyridine, bis(4-aminophenyl)phosphine oxide, bis(4-aminophenyl)-N-methylamine, 1,5 -diaminonaphthalene, 3,
3'-dimethyl-4,4'-diaminobiphenyl,
3,3'-dimethoxybenzidine, 2,4-bis(β-amino-t-butyl)toluene, bis(p
-β-amino-t-butylphenyl) ether,
p-bis(2methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, m-xylylenediamine,
p-xylylenediamine, bis(p-aminocyclohexyl)methane, ethylenediamine, propylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 3
-Methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminodecane, 1,2-bis(3-aminopropoxy)
Ethane, 2,2-dimethylpropylene diamine,
3-methoxyhexamethylene diamine, 2,5-
Dimethylhexamethylenediamine, 2,5-dimethylnonamethylenediamine, 1,4-diaminocyclohexane, 2,12-diaminooctadecane,
2,5-diamino-1,3,4-oxadiazole and the like.

Furthermore, among the tetracarboxylic dianhydrides used in the present invention, an essential component is 3,3',4,4'-benzophenone tetracarboxylic dianhydride. However, other tetracarboxylic dianhydrides can of course also be used. For example, pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 1,2,5,6- Naphthalenetetracarboxylic dianhydride, 2,2',3,3'-
Diphenyltetracarboxylic dianhydride, 2,2-
Bis(3,4-dicarboxydiphenyl)propane dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxydiphenyl)ether dianhydride, ethylenetetracarboxylic acid dianhydride, naphthalene-1,2,4,
5-tetracarboxylic dianhydride, naphthalene-
1,4,5,8-tetracarboxylic dianhydride,
4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5, 8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,
8-tetracarboxylic dianhydride, 2,3,4,7
-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,
2,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, pyrazine 2 , 3,5,6-tetracarboxylic dianhydride, 2,2-bis(2,5
- dicarboxyphenyl) propane dianhydride,
1,1-bis(2,3-dicarboxyphenyl)
Ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(2,3
-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 1,2,3,4- Butanetetracarboxylic dianhydride, thiophene-2,3,4,5
-tetracarboxylic dianhydride, etc. The amount of 2,8-diaminodiphenylene oxide, which is an essential component, is preferably 0.5 to 50 mol%. If it is less than 0.5 mol%, the effect of improving heat resistance strength is small and 50 mol%
With the above, the molecular weight does not increase, probably due to steric hindrance in the molecular structure. In addition, the amount of 2,4-diaminotoluene 3,3',4,4'-benzophenonetetracarboxylic dianhydride used is preferably 20 mol% or more, and if it is less than this, the color-free improvement effect will not be achieved. small. Further, the amount of 1,3-bis(3-aminopropyl)tetramethyldisiloxane used is preferably 0.1 to 30 mol%. If it is less than 0.1 mol %, the effects of color-free and adhesive improvement will be small, and if it is more than 30 mol %, the cured product will be brittle.

In the present invention, the reaction between diamines and tetracarboxylic dianhydrides is preferably carried out in equimolar amounts as much as possible, which increases the degree of polymerization. If the amount of either raw material increases by 5% or more, the degree of polymerization will drop significantly and a low molecular weight product with poor film-forming properties will be produced, so care must be taken. Usually, one raw material is
Using 3% more is often done to improve workability and processability.

The solvent of the reaction system in the present invention is an organic polar solvent whose functional group has a dipole moment that does not react with the tetracarboxylic dianhydride or diamines.

In addition to being inert to the system and solvent to the product, the organic polar solvent must be solvent to at least one, preferably both, of the reaction components.

Typical solvents of this type are N,N-
Dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N,N
-diethylacetamide, N,N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphoamide, N-methyl-2-pyrrolidone, pyridine, dimethylsulfone, tetramethylenesulfone, dimethyltetramethylenesulfone, etc. These solvents can be used alone or used in combination.

Other solvents that can be used in combination include benzene, benzonitrile, dioxane,
Nonsolvents such as butyrolactone, xylene, toluene, and cyclohexane are used as dispersion media for raw materials, reaction regulators, solvent volatilization regulators from products, film smoothing agents, and the like.

It is generally preferred that the present invention be carried out under anhydrous conditions.

This is because the tetracarboxylic dianhydride is ring-opened by water, becomes inactivated, and there is a risk of stopping the reaction.

Therefore, it is necessary to remove both the moisture in the raw materials and the moisture in the solvent.

However, water is sometimes intentionally added to adjust the progress of the reaction and control the degree of resin polymerization.

Further, the present invention is preferably carried out in an inert gas atmosphere.

This is to prevent oxidation of diamines.

Dry nitrogen gas is generally used as the inert gas.

The reaction in the present invention can be carried out in the following various ways.

(1) Diamines and tetracarboxylic dianhydride are mixed in advance, and the mixture is added little by little to an organic solvent while stirring. This method is relatively advantageous in exothermic reactions such as those for polyimide resins.

(2) Conversely, there is also a method of adding a solvent to a mixture of diamines and tetracarboxylic dianhydride while stirring.

(3) A commonly used method is to dissolve only diamines in a solvent, and then add tetracarboxylic dianhydride to this in a proportion that allows the reaction rate to be controlled.

(4) It is also possible to dissolve diamines and tetracarboxylic dianhydride separately in a solvent and then slowly add the two solutions in a reactor.

(5) Furthermore, it is also possible to prepare in advance a polyamic acid product containing an excess of diamines and a polyamic acid product containing an excess of tetracarboxylic dianhydride, and then further react them in a reactor.

(6) Among the diamines, there is also a method in which a part of the diamine compound and tetracarboxylic dianhydride are first reacted and then the remaining diamine compound is reacted, or the reverse method is also available.

(7) In addition, among the diamines, some diamine compounds and tetracarboxylic dianhydride are reacted, and the remaining diamine compound and tetracarboxylic dianhydride are reacted. Another method is to mix it beforehand.

The reaction temperature is preferably 0 to 100°C. This is because if the temperature is below 0°C, the reaction rate is slow, and if it is above 100°C, the produced polyamic acid gradually starts the ring-closing reaction.

Usually, the reaction is carried out at around 20°C. The degree of polymerization of polyamic acid can be controlled in a planned manner.
In order to control the degree of polymerization, it is also possible to end-block with phthalic anhydride or aniline, or add water to ring-open one of the acid anhydride groups to inactivate it.

When used, the polyamic acid product produced by the method of the present invention has the adhesion and adhesion properties of various silane coupling agents, borane coupling agents, titanate coupling agents, aluminum coupling agents, and other chelate coupling agents. Improvers, various solvents, and flow agents may be added, and in addition to these, ordinary acid curing agents, amine curing agents,
Small amounts of polyamide curing agents and curing accelerators such as imidazole and tertiary amines may be added, as well as flexibility agents and viscosity modifiers such as rubber, polysulfide, polyester, and low-molecular epoxy, talc, clay, mica, Fillers such as feldspar powder, quartz powder, and magnesium oxide; colorants such as carbon black and phthalocyanine blue; flame retardants such as tetrabromophenylmethane and tributyl phosphate;
Small amounts of flame retardant aids such as antimony trioxide, barium metaborate, etc. may also be added, and their addition opens up many applications.

The polyamic acid product produced by the method of the present invention is imidized and cured by heating or by using a dehydrating agent. The heating temperature for the former thermal dehydration treatment is usually 50°C or higher, preferably 150°C or higher, preferably 200 to 400°C. Although air may be used as the atmosphere in this case, it is often preferable to use non-oxidizing conditions such as reduced pressure or inert gas. As the latter dehydrating agent, carboxylic anhydrides such as acetic anhydride, propionic anhydride, and benzoic anhydride are often used, and these are particularly effective when used in the coexistence of basic substances such as pyridine and quinoline. Solid dehydrating agents include zeolite-based molecular sieves, silica gel, and activated alumina, which are more effective when used after being slightly heated.

〔Effect of the invention〕

According to the method of the invention, 2,8-diaminodiphenylene oxide, 2,4-diaminotoluene, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 3,3',4,4 A polymer containing '-benzophenonetetracarboxylic dianhydride as an essential component is an excellent heat-resistant resin that has a good balance of heat resistance, flexibility, light color, and adhesiveness.

That is, the polymer synthesized by the method of the present invention is
By using 2,8-diaminodiphenylene oxide, it has a large number of aromatic rings and heterocycles in its molecular structure, and has excellent heat resistance. In addition, the main chain has a helical shape, which is thought to give it excellent flexibility with a spring-like effect. Furthermore, 2,4-diaminotoluene and 3,3′,
A heat-resistant resin with little coloring can be obtained, probably because the main chain cannot form a conjugated structure due to the introduction of 4,4'-benzophenonetetracarboxylic dianhydride. Furthermore, by introducing 1,3-bis(3-aminopropyl)tetramethyldisiloxane, the imide group content is diluted, and a heat-resistant resin with less coloring and good adhesiveness can be obtained.

Specifically, the uses of the present invention are as follows:
First, it is used as a coating film to protect the surfaces of various electronic equipment, and as a heat-resistant insulating film for multilayer wiring on top of it.

For example, semiconductors, transistors, linear ICs,
Hybrid IC, light emitting diode, LSI, super LSI
It is a wiring structure for electronic circuits such as.

Next, since the heat-resistant resin of the present invention is light-colored, it can also be used as an alignment film for liquid crystal display devices. That is, the polymer solution of the present invention is applied to a glass substrate or a plastic film substrate on which a transparent conductive film containing tin oxide or indium oxide as a main component is formed by a dipping method, a spin coating method, a spray method, a printing method, etc. After heat curing, rubbing treatment is performed. The rubbing method can be performed using gauze, buffing, or other conventional means. Liquid crystals that can be used in combination with the alignment film of the present invention include nemate liquid crystals such as Schiff base type liquid crystals, phenylcyclohexane type liquid crystals, azoxy type liquid crystals, azo type liquid crystals, biphenyl type liquid crystals, ester type liquid crystals, and phenyl-pyrimidine type liquid crystals; Examples include cholesteric liquid crystals in which optically active compounds such as optically active substances, cholesterol compounds, biphenyl derivatives having optically active substituents, and phenylbenzoates are added to the above-mentioned nematic liquid crystals. Other high-temperature coating varnishes include electric wire coatings, magnet wires, dipping coatings for various electrical parts, and protective coatings for metal parts.They can also be used as impregnation varnishes for glass cloth, fused silica cloth, graphite fibers, and boron fibers. It is used for the impregnation of radar domes, printed circuit boards, radioactive waste containers, turbine blades, spacecraft and other structural parts that require high temperature performance and good electrical properties, and for the prevention of microwave radiation. It is also used as an interior material for waveguides in computers, atomic equipment, and X-ray equipment.

It is also used as a molding material to create self-lubricating sliding surfaces by adding graphite powder, graphite fiber, molybdenum disulfide, and polytetrafluoroethylene, and is used for piston rings, valve seats, bearings, seals, etc. It is also used to make jet engine parts, high-strength structural molded parts, etc. by adding glass fiber, graphite fiber, or boron fiber.

Furthermore, it is used as a high-temperature adhesive for bonding electrical circuit parts and structural parts of spacecraft.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 A four-necked separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet was
29.735 g (15 mol%) of purified anhydrous 2,8-diaminophenylene oxide, 79.411 g (65 mol%) of 2,4-diaminotoluene, and 1,3-bis(3-aminopropyl)tetramethyldi Take 49.704 g (20 mol%) of siloxane and add a mixed solvent of 95% by weight of anhydrous N-methyl-2-pyrrolidone and 5% by weight of xylene until the solid content in the total raw material is 15% by weight. amount was added and dissolved. Dry nitrogen gas was kept flowing throughout the entire process from the reaction preparation stage to product removal.

Then, 322.230 g of purified anhydrous 3,3',4,4'-benzophenonetetracarboxylic dianhydride
(100 mol %) was added little by little while stirring, but since it was an exothermic reaction, it was cooled by circulating cold water at about 15°C in an external water tank. After the addition, the internal temperature was set at 20°C and stirred for 14 hours to complete the reaction.

The obtained product is a transparent yellow and extremely viscous polyamic acid solution, and the intrinsic viscosity of a 0.5% by weight solution of N-methyl-2-pyrrolidone is 0.59 (30°C).
It was hot.

Next, a 5% by weight solution of this polyamic acid in N-dimethylacetamide was dropped onto a glass plate and spun at 100 rpm/min for 10 seconds and then 2000 rpm/min for 20 seconds using a spinner to spread it evenly. did. This was done at 80℃, 150℃, and 250℃ under reduced pressure.
℃ and 350℃ for 30 minutes each to cause dehydration and ring closure to obtain a pale yellow, transparent and tough polyimide resin film with a thickness of 1 μm. Looking at the infrared absorption spectrum of this film, strong absorption based on the imide ring was observed at 1780 cm ^-1 and 730 cm ^-1 and strong absorption based on the furan ring was observed at 1200 cm ^-1 .

This film has extremely excellent heat resistance, and the thermal decomposition onset temperature in air was 505°C at a heating rate of 5°C/min, as measured by a differential thermal balance analyzer. The film also had high strength, with an excellent tensile strength of 15 kg/mm ² at 200°C. Furthermore, the film had excellent hypochromic properties and a light transmittance of 91% at 400 nm. Furthermore, in a Cellotape peeling test (JIS-D-2020) on a glass plate, the peeling rate was 0%, indicating excellent adhesion.

Example 2 Using the same apparatus and method as in Example 1, 49.558 g (25 mol%) of 2,8-diaminodiphenylene oxide, 48.868 g (40 mol%) of 2,4-diaminotoluene, and 4,4'- Diaminodiphenyl ether
40.048g (20mol%) and 37.278g of 1,3-bis(3-aminopropyl)tetramethyldisiloxane
g (15 mol%) and 225.561 g (70
mol%) and 65.436 g of pyromellitic dianhydride (30
mol%).

The obtained product was a transparent yellow and extremely viscous polyamic acid solution with an inherent viscosity of 0.61. In addition, the obtained film was pale yellow and transparent and had excellent toughness, with a thermal decomposition initiation temperature of 510℃, hot tensile strength of 15Kg/mm ² , light transmittance of 88%, and cellophane peeling rate of 0%. It was hot.

Comparative Example 1 Using the same apparatus and method as in Example 1, 122.170 g (100 mol%) of 2,4-diaminotoluene and 3,
322.230 g (100 mol %) of 3',4,4'-benzophenonetetracarboxylic dianhydride was reacted.

The obtained film had excellent light color properties, but the temperature at which thermal decomposition started was only 320°C.
The hot tensile strength was 5 kg/mm ² , and the cellophane tape peeling rate was 95%, which was poor and could not withstand rubbing work at all.

Comparative Example 2 Using the same apparatus and method as in Example 1, 97.736 g (80 mol%) of 2,4-diaminotoluene and 1,3-
49.704 g (20 mol%) of bis(3-aminopropyl)tetramethyldisiloxane and 3,3',4,
4′-Benzophenonetetracarboxylic dianhydride
322.230g (100 mol%) was reacted.

The obtained film had excellent light color properties and good adhesion, but the thermal decomposition initiation temperature was only 315° C. and the hot tensile strength was only 4 Kg/mm ² .

Comparative Example 3 Using the same apparatus and method as in Example 1, 19.823 g (10 mol%) of 2,8-diaminodiphenylene oxide and 109.953 g (90 mol%) of 2,4-diaminotoluene were prepared.
mol%) and 322.230 g (100 mol%) of 3,3',4,4'-benzophenonetetracarboxylic dianhydride were reacted.

The obtained film had excellent light color property, high thermal decomposition initiation temperature, and strong hot tensile strength, but the cellophane tape peeling rate was poor at 100%.

Claims (1)

[Claims] 1. In a method for producing a polyimide resin comprising a tetracarboxylic dianhydride and a diamine, as the tetracarboxylic dianhydride component, 3,3',4,
4′-benzophenonetetracarboxylic dianhydride
Contains 20 mol% or more, as a diamine component, 2,
8-diaminodiphenylene oxide, 2,4-
0.5 each of diaminotoluene and 1,3-bis(3-aminopropyl)tetramethyldisiloxane
~50 mol%, 20 mol% or more, 0.1 to 30 mol%, the molar ratio of tetracarboxylic dianhydride and diamine is 100:95 to 105, and the reaction is carried out at a temperature of 0 to 100°C. A method for producing a heat-resistant resin.