JPS61181827A - Production of heat-resistant resin - Google Patents

Abstract

PURPOSE:To improve the balance of the obtained polyimide resin among heat resistance, flexibility and color lightness, by using specified compounds as tetracarboxylic acid dianhydride and diamine components. CONSTITUTION:3,3',4,4'-Benzophenonetetracarboxylic dianhydride is used as an essential component of the tetracarboxylic acid dianhydride component. 2,8-Diaminodiphenylene oxide and 2,4-diaminotoluene are used as essential components of the diamine component. It is preferable that the tetracarboxylic acid dianhydride component contains 20mol% or above 3,3',4,4'-benzophe nonetetracarboxylic dianhydride. It is preferable that the diamine component contains 0.5-50mol% 2,8-diaminodiphenylene oxide and 20mol% or above 2,4- diaminotoluene.

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. K provides a heat-resistant resin useful as an alignment film for devices.

[Prior art]

Conventionally, polymers having heterocycles such as imide, imidazole, thiazole, oxazole, oxadiazole, triazole, quinoxaline, thiadiazole, oxazinone, quinazoline, imidazopyrrolone, isoindoroquinazolone, etc. in the main chain of the polymer have good heat resistance. It is well known that it is superior. However, these known polymers have rigid polymer main chains, and when formed into films, films, or coatings, they have poor flexibility, flexibility, and elongation. Therefore, for example, when used as an alignment film for liquid crystal,
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, when used as an alignment film for a liquid crystal, for example, the liquid crystal display element becomes brownish, the visual field becomes dark, the contrast decreases, and it no longer functions as a display element. From this point of view, various studies have been made in the past to achieve a balance between heat resistance, flexibility, and light color property, but as shown in the cross-reaction equation, as one improves, the other deteriorates. Become.

It was an example.

[Purpose of the invention]

As a result of studies aimed at overcoming such drawbacks, the present invention uses 2,8-diaminodiphenylene oxide and 2,4-diaminotoluene as diamine components, and
3.3' as a tetracarboxylic dianhydride component, 4.
4. We have discovered that by using benzophenone tetracarboxylic dianhydride as an essential component, a heat-resistant resin with a good balance of heat resistance, flexibility, and light color can be obtained, and we have completed the present invention. This is what happened.

[Structure of the invention]

In the present invention, when forming an imide ring by reacting a diamine and a tetracarboxylic dianhydride, 2,8-diaminodiphenylene oxide and 2,4
-diaminotoluene, and 3=3,4,4,hensiphenonetetracarboxylic dianhydride as an essential component. be.

Among the diamines used in the present invention, essential components are 2°8-diaminodiphenylene oxide and 2,4-diaminotoluene. The reaction formula for one method for producing 2,8-diaminodiphenylene oxide is as follows.

Diphenylene oxide 2,8-dibromodiphenylene oxide 2,8-diaminodiphenylene oxide 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-7enylenediamine, 414, diaminodiphenylpro, 6-ton, 4t4, diaminodiphenylmethane, benzidine, 4
y4, diaminodiphenylsulfite, 4°4'-diaminodiphenylsulfone, 3.3, diaminodiphenylsulfone, 4.4, diaminodiphenyl ether, 2.
6-diamitubiridine, bis(4-aminophenyl)phosphine oxyto, 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-+-i
Noventyl)benzene, p-bis(Ll-dimethyl-5
-Amitinthyl)benzene, m-xylylenediamine, p-xylylenediamine, bis(p-aminocyclohexyl)methane, ethylenediamine, propylenediamine, hexamethylenediamine, hezotamethylenediamine, octamethylenediamine, nonamethylenediamine, deca Methylenediamine, 3-methylhbutamethylenediamine, 4.4-dimethylhbutamethylenediamine, 2.11-
Diaminodecane, 1,2-bis(3-aminopronoxy)ethane, 2,2-dimethylpropylenediamine, 3-
Methoxyhexamethylene diamine, 2,5-dimethylhexamethylene diamine, 2,5-dimethylnonamethylene diamine, 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,
The essential component is 3.3'? 4.4, benzophenone tetracarboxylic dianhydride. However, other tetracarboxylic dianhydrides can of course also be used. For example, pyromellitic dianhydride, 2t3, 6.7-naphthalenetetracarboxylic dianhydride, 3,3', 4.4, diphenyltetracarboxylic dianhydride, 1.2,5.6-
7talentetracarboxylic acid dianhydride, 2, 2', 3
．． 3, diphenyltetracarboxylic dianhydride, 2.2-
Bis(3,4-dicarboxydiphenyl)fluorozone 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-cyclonaphthalene-1
．． 4,5.8-tetracarboxylic dianhydride, 2゜7-cyclonaphthalene-1-4+5.8-tetracarboxylic dianhydride, 2.3.4.7-titrachloronaphthalene-1.4, 5.8-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, cyclointane-1,2,314-tetracarboxylic dianhydride, pyrrolidine-2,3, 4,5-tetracarboxylic dianhydride, pyrazine 2+ 3,5t 6-tetracarboxylic dianhydride, 2,2-bis(2,5-dicarboxyphenyl)furono dianhydride, 1,1-bis (2,
3-dicarboxyphenyl)ethane anhydride, 1.1-
bis(3149carboxyphenyl)ethane anhydride,
Bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfonic anhydride, benzene-1t2t3*4-tetracarboxylic dianhydride, 1,2,3.4-butane These include tetracarboxylic dianhydride, thio7ene-2.3.4.5-tetracarboxylic dianhydride, and the like. 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 mole, the effect of improving heat resistance strength is small, and if it is more than 50 mole, the molecular weight will not increase, probably due to steric hindrance of the molecular structure. In addition, the amount of 2,4-diaminodecante L 3'* 4* 4, benzophenone tetracarboxylic dianhydride used is preferably 20 mol or more, and if it is less than this, the effect of improving coloration is small. The reaction between diamines and tetracarboxylic dianhydrides is preferably carried out in equimolar amounts as much as possible;
The degree of polymerization also increases. 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, it is common practice to use 1 to 3 m more of one raw material in order 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 daizel moment that does not react with the tetracarboxylic dianhydride or diamines.

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

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

Other non-solvents that can be used in combination as solvents include benzene, benzonitrile, dioxane, butyrolactone, xylene, toluene, and cyclohexane.
It is used as a dispersion medium for raw materials, a reaction control agent, a volatilization control agent for solvents from products, a film smoothing agent, etc.

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

This is because the tetracarboxylic dianhydride may be ring-opened by water, inactivating it, and stopping the reaction.

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

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

Further, the present invention is preferably carried out in an inert gas atmosphere. This is to prevent oxidation of the 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. Jin's method is relatively advantageous in exothermic reactions such as 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 add tetracarboxylic dianhydride to this in a proportion that allows control of the reaction rate.

(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 t' IJ amic 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 portion of the diamine compound and tetracarboxylic dianhydride are first reacted, and then the remaining diamine compound is reacted, or the reverse method.

(7) In addition, a mixture obtained by reacting a part of the diamine compound with tetracarboxylic dianhydride, and a mixture obtained by reacting the remaining diamine compound with tetracarboxylic dianhydride are used. 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 nine polyamic acid produced 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 can be used with various silane coupling agents, poran coupling agents, titanate coupling agents, aluminum coupling agents, and other chelate-based adhesives. Properties improvers, various solvents, and flow agents may be added, and in addition to these, small amounts of ordinary acid curing agents, amine curing agents, I-lyamide curing agents, and curing accelerators such as imidazole and tertiary amines may be added. It is also suitable for use with rubber and buris, flexibility agents and viscosity modifiers such as fido, polyester, and low-molecular-weight edaxies, fillers such as talc, clay, mica, feldspar powder, quartz powder, and magnesium oxide, carbon black, A small amount of a coloring agent such as phthalocyanine blue, a flame retardant such as tetrabromophenylmethane or tributyl phosphate, or a flame retardant aid such as antimony trioxide or barium metaborate may be added. It opens up many uses.

The amic acid product produced by the method of the present invention is diimidized and hardened by heating or using a dehydrating agent. The heating temperature for the former heating dehydration treatment is usually 50°C or higher, especially 15°C.
The temperature range is preferably 0°C or higher and 200 to 400°C. In this case, air may be used as the atmosphere, but non-oxidizing conditions such as reduced pressure or inert gas are often preferable. 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. In addition, solid dehydrating agents such as zeolite-based Molecule Sieve, silica gel, and activated alumina are more effective when used after being slightly heated.

〔Effect of the invention〕

According to the method of the present invention, 2,8-diaminodiphenylene oxide, 2,4-diaminotoluene, and L 3'+
4*4, benzophenonetetracarboxylic acid dianhydride,
Polymers containing these as essential components are excellent heat-resistant resins that have a good balance of heat resistance, flexibility, and light color.

That is, the polymer synthesized by the method of the present invention has a 2.8-
By using 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 provide excellent flexibility due to a spring-like effect.

Furthermore, 2,4-diaminotoluene and 3s3't4-4,
The introduction of benzophenonetetracarboxylic dianhydride prevents the main chain from forming a conjugated structure, resulting in a heat-resistant resin with little coloring. Specifically, the present invention is used as a coating film for protecting the surfaces of various electronic equipment, and as a heat-resistant insulating film for multilayer wiring thereon.

For example, semiconductors, transistors, and linear ICs.

High Prix) IC1 light emitting diode, LSI, ultra LS
This is a wiring structure for electronic circuits such as I.

Secondly, since the heat-resistant resin of the present invention is light in color, 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 i/dium oxide as a main component is formed by a dipping method, a spin coating method, a spray method, a printing method, etc. After applying and heating and curing,
Rubbing treatment. The rubbing method can be performed using gauze, puff polishing, or other conventional means. Liquid crystals that can be used in combination with the alignment film of the present invention include nematic liquid crystals such as thick 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 nematic liquid crystals. In addition, it is used as a coaching varnish for high temperatures, as a coating for electric wires, magnet wires, dip coatings for various electrical parts, and as a protective coating for metal parts.
Used to impregnate glass cloth, fused silica cloth, graphite fibers and boron fibers for radar domes, printed circuit boards, radioactive waste containers, turbine blades, spacecraft and other structural parts that require high temperature performance and excellent electrical properties. It is also used as an interior material for waveguides in convenience stores, atomic equipment, and X-ray equipment to prevent microwaves and radiation.

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,
Glass fibers, graphite fibers, and boron fibers are added to make jet engine parts and high-strength structural molded parts.

It is also 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 29.73 ml of purified anhydrous 2,8-diaminodiphenylene oxide was placed in a four-necked senozo rubble flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet.
59 (15 molti) and 2,4-diaminotoluene 1
Take 03.845 f (85 moles) 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 materials is 15% by weight. Add enough amount to dissolve. Dry nitrogen gas was kept flowing throughout the entire process from the preparatory stage of the reaction to the removal of the product.

Then purified anhydrous 3.3', 4, 4, benzophenone tetracarboxylic dianhydride 322.239 (1
00 molti) 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 temperature at the rear end was set at 20° C., and the mixture was stirred for 12 hours to complete the reaction.

The product obtained is a clear yellow, extremely viscous 4+) amic acid solution containing 0.5 N-methyl-2-pyrrolidone.
The intrinsic viscosity of the wt% solution was α76 (30°C).

Next, a 5% by weight solution of this pyriamic acid t-N-dimethylacetamide was dropped onto a glass plate.
It was rotated with a spinner at 40 rpm/min for 10 seconds and then at 2000 rpm/min for 20 seconds to uniformly apply the coating. This was heated at 80℃ and 150℃ under reduced pressure.
The mixture was then heated at 250° C. and 350° C. for 30 minutes each to cause dehydration and ring closure, thereby obtaining 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 (@' and 730 an-") and strong absorption based on the furan ring was observed at 1200".

This film has extremely excellent heat resistance, and the starting temperature of thermal decomposition in air was 510°C at a heating rate of 5°C/min, as measured using a differential thermal balance analyzer. The film has great strength, with a tensile strength of 14 kg/200°C.
It was excellent. Further, the film had excellent light color property, and the light transmittance was 90 degrees at 400°C.

Example 2 Using the same apparatus and method as in Example 1, 39.646 t (20 mol) of 2,8-diaminodiphenylene oxide and 79.411 t (20 mol) of 2,4-diaminotluay were prepared. (
65 mol%) 4.4, diaminodiphenyl ether 3
0.036 t (15 mol%), 313', 4.
4. Benzophenone tetracarboxylic dianhydride 193.
338 F (60 mol%) and pyromellitic dianhydride 8
7.248f (40 molti) K reaction was carried out.

The obtained product was a transparent yellow and extremely viscous amic acid solution with an inherent viscosity of 0.82. In addition, the obtained nine-film is pale yellow and transparent and has high toughness, with a thermal decomposition initiation temperature of 515°C and a hot tensile strength of 16 kg/m.
The light transmittance was excellent at 82%.

Comparative Example 1 Using the same apparatus and method as in Example 1, 2,4-diaminotoluene 12Z170 F (100 molti) and 3°3'
, 4,4'-benzophenonetetracarboxylic dianhydride 322-230 f (100 mol).

The obtained film was pale yellow and transparent, but the thermal decomposition initiation temperature was only 320°C, and the tensile strength was 5 kq/w, so it could not withstand the web/guing work at all.

Comparative Example 2 2,8-diaminodiphenylene oxide 11a938f (60 mok
%), 4.4'-diaminodiphenyl ether 8α096f (40 mol) was subjected to a VC reaction with pyromellitic dianhydride 21 & 120 f (1 (10 mol %)).

Although the obtained film was heat resistant and tough, it had a light transmittance of only 519b, and could not be used as a liquid crystal aligning film at all.

Claims (4)

[Claims] (1) 3,3,4,4'-benzophenone tetracarboxylic dianhydride is used as the tetracarboxylic dianhydride component of the polyimide resin consisting of tetracarboxylic dianhydride and diamine, and 2, A method for producing a heat-resistant resin, comprising 8-diaminodiphenylene oxide and 2,4-diaminotoluene as essential components. (2) Claim 1, characterized in that it contains 20 mol% or more of 3,3',4,4'-benzophenone tetracarboxylic dianhydride as a tetracarboxylic dianhydride component. A method for producing the heat-resistant resin described above. (3) The method for producing a heat-resistant resin according to claim 1, which contains 0.5 to 50 mol% of 2,8-diaminodiphenylene oxide as a diamine component. (4) The method for producing a heat-resistant resin according to claim 1, which contains 20 mol% or more of 2,4-diaminotoluene as a diamine component.