JPS6284122A - Production of heat-resistant resin - Google Patents

Abstract

PURPOSE:The reaction between a specific tetracarboxylic anhydride and a specific diamine under specific conditions gives a resin which is used as an oriented liquid crystal membrane of high light transmission, because it is well balance among heat resistance, flexibility, light coloring and cold curability. CONSTITUTION:The reaction between a tetracarboxylic dianhydride component containing more than 5mol% of 3,3',4,4'-benzophenonetetracarboxylic dianhydride and a diamine component containing more than 20mol% of an aliphatic diamine of 30 or less carbon atoms is carried out at 50-200 deg.C under anhydrous conditions in a solvent such as N,N-dimethylformamide in an inert gas atmosphere. The 2 components used in the reaction are preferably equimolar.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a heat-resistant resin that has excellent light transmittance, can be cured at low temperatures, and has excellent alkali resistance. The purpose of this is that the imidized resin has excellent heat resistance, abrasion resistance, chemical resistance, electrical insulation, film forming properties, flexibility, mechanical properties, etc. as a Hi-IJ imide resin, and is used for electronic devices. We provide heat-resistant resins useful as materials, electrical insulation materials, coatings, adhesives, paints, molded products, laminates, fibers, film materials, etc. Among them, we particularly provide alignment films for liquid crystal display elements for electronic devices. The purpose of the present invention is to provide a heat-resistant resin useful as a heat-resistant resin.

[Prior art]

Conventional polymer main chains contain heterocycles, such as ibad, imidazole, thiazole, oxazole, oxadiazole,
It is well known that compounds containing triazole, quinoxaline, thiadiazole, oxazinonequinazoline, imidazopyrrolone, indolokinazolone, 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, and elongation. 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.

Further, these polymers require heating to 200'C or more during curing, and when heated, 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, and the contrast decreases, making it impossible to function as a display element.

On the other hand, if the transparent substrate used in the liquid crystal display element is a conventional glass substrate, there would be no particular problem even if it is cured by heating at a high temperature of 200°C or higher, but in the case of plastic film substrates, which have become widely used in recent years. However, the film cannot withstand the heating temperature and is deformed, making it impossible to obtain a normal liquid crystal display element.

[Purpose of the invention]

As a result of studies aimed at overcoming these drawbacks, the present invention uses an aliphatic diamine having 30 or less carbon atoms as the diamine component, and 3.3', 4. as the tetracarboxylic dianhydride component.
By reacting 4'-benzophenonetetracarboxylic anhydride as an essential component in an organic polar solvent at a temperature of 50°C to 200°C, properties such as heat resistance, flexibility, light color, and low-temperature curing properties can be achieved. It was discovered that a heat-resistant resin with good heat resistance can be obtained, and the present invention was completed.

[Structure of the invention]

In the present invention, when forming an imide ring by reacting a tetracarboxylic dianhydride and a diamine, \, 3.3',
4.4'-benzophenone Tetracarboxylic acid dianhydride component containing 5 mole or more of tetracarboxylic acid dianhydride and hydrate and a diamine component containing 20 mole or more of aliphatic diamine having 30 or less carbon atoms as essential components, 50 to 200 This is a method for producing a heat-resistant resin, characterized in that the reaction is carried out at a temperature of °C.

Aliphatic diamines with a carbon number of 30 or less used as diamine components include ethylene diamine, propylene diamine, hexamethylene diamine, dodecamethylene diamine, etc., but of course aromatic diamines such as the following are also used in combination to impart various properties. be able to.

Examples, t td m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylzolonon, 4,4'-diaminodiphenylmethane, benzidine,
4.4'-diaminodiphenyl sulfide, 4.4'-
Diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, 2,6-diamitupyridine, bis(4
-aminophenyl)phosphine oxyto, bis(4-aminophenyl)-N-methylamine, 1,5-diaminonaphthalene, 3. Codimethyl-4゜4'-diaminobiphenyl, 3,3'-dimethoxypenzidine, 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-amintinchyl)benzene, m-xylylenediamine, p- xylylenediamine,
Bis(p-aminocyclohexyl)methane and the like.

Furthermore, among the tetracarboxylic dianhydrides used in the present invention,
The essential component is 3,3',4,4'-benzophenonetetracarboxylic dianhydride. However, other tetracarboxylic dianhydrides can of course be used in combination. 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)prono-Z dianhydride, 3,4,9.10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxydiphenyl)
Ether dianhydride, ethylenetetracarboxylic dianhydride, naphthalene-1,2,4,5-tetracarboxylic dianhydride, naphthalene-1t4+5t8-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, 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)solono-Z 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)sulfonic anhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, L2p3+4-f tantetracarboxylic dianhydride, thiophene-2,3,4 , 5,-tetracarboxylic dianhydride. The amount of aliphatic diamine with a carbon number of 30 or less, which is an essential ingredient, is 20% of the total diamine component.
More than molty is preferable. If the amount is less than 20 molti, the effect of improving the color-free state is small. Also, the number of carbon atoms in aliphatic diamine is 30
The following are preferred. If an aliphatic diamine with a larger number of carbon atoms is used, the reaction with the tetracarboxylic dianhydride will be difficult to proceed quantitatively, and it will remain in the reaction system as an unreacted product. Reactants may be oxidized and cause coloration.

Further, the amount of 3, 3', 4,4'-benzophenone tetracarboxylic dianhydride used is preferably 5 mole or more based on the total tetracarboxylic dianhydride component, and if it is less than this, the effect of improving coloration is small. . Furthermore, when reacted with an aliphatic diamine having 30 or less carbon atoms at a relatively high temperature of 50°C to 200°C, it is normal that the formed amic acid gradually undergoes ring closure and forms a precipitate. γ, 4.4
'-benzophenonetetracarboxylic dianhydride Total dianhydride Rubonic acid dianhydride When using 5 mol or more of the dianhydride component, this problem does not occur and it is possible to maintain the reaction system as a homogeneous solution.

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 moles 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 0 to 3 molt 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 does not react with the tetracarboxylic dianhydride or diamines. In addition to being inert to the system and being a solvent for the products, the organic polar solvent must be a good 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, dimethyltetramethylene There are sulfones, etc., and these solvents are 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 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 prevents the oxidation of diamines and removes carbon dioxide from the air.

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 hirimide 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 noriamic 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, one in which a part of the diamine compound among the diamines is reacted with tetracarboxylic dianhydride, and one in which the remaining diamine compound and tetracarboxylic dianhydride are reacted, Another option is to mix it before use.

The reaction temperature is 50°C to 200°C. If the temperature is below 50°C, the reaction is slow and the ring-closing reaction of the polyamic acid is difficult to occur, and the subsequent curing requires high-temperature heating of 200°C or above, making it impossible to exhibit low-temperature curability. 20 again
If the reaction is carried out at 0°C or higher, side reactions such as hydrolysis become active and it becomes impossible to obtain a product with a high degree of polymerization.

The degree of polymerization of polyamic acid can be controlled in a planned manner.

In order to control the degree of polymerization, the theramic acid product produced by the method of the present invention by adding water and end-capped with phthalic anhydride or aniline can be used with various silane coupling agents, Borane coupling agents, titanate coupling agents, aluminum coupling agents, chelate-based adhesion/adhesion improvers, various solvents, flow agents may be added, and in addition to these, ordinary acid curing agents, Small amounts of curing accelerators such as amine curing agents, polyamide curing agents, imidazole, and tertiary amines may be added, and flexibility agents and viscosity modifiers such as rubber, polysulfide, polyester, and low-molecular-weight epoxies, talc, Fillers such as clay, mica, feldspar powder, quartz powder, magnesium oxide, colorants such as carbon black and phthalocyanine blue, flame retardants such as tetrabromophenylmethane and tributyl phosphate, and difficult materials such as antimony trioxide and barium metaborate. Small amounts of combustion aids may also be added, and their addition opens up many applications.

The resin face produced by the method of the present invention completes imidization and hardens by heating or using a dehydrating agent. 50℃
In the reaction process at ~200°C, more than 7 parts of polyamide
Since phosphoric acid is ring-closed to form an imide ring, it is preferable that the heating temperature for the thermal dehydration treatment is usually 50°C to 200°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. Also, as a solid dehydrating agent, Zeo 2
・There are atomic-based molecular sieves, silica gel, activated alumina, etc., which are more effective if used after being slightly heated.

〔Effect of the invention〕

According to the method of the present invention, an aliphatic diamine having 30 or less carbon atoms and 3.3', 4,4'-benzophenonetetracarboxylic dianhydride are essential components, and the mixture is heated at 50°C to 50°C in an organic polar solvent.
The polymer obtained by reacting at a temperature of 200° C. is a heat-resistant resin with well-balanced properties such as heat resistance, flexibility, low-temperature curability, and light color property.

That is, the polymer synthesized by the method of the present invention contains an aliphatic chain in its molecular structure due to the use of an aliphatic diamine having 30 or less carbon atoms, and is colored because the main chain cannot form a conjugated structure. It is possible to obtain a heat-resistant resin with less Also, unlike ordinary aromatic diamines, since it contains an aliphatic chain between amine groups, the amide group has a high degree of freedom in the polyamic state, so it closes at a relatively low temperature to form an imide ring. For this reason, it has become possible to cure at a low temperature of 200°C or less. moreover,
By using 3,3',4,4'-benzophenonetetracarboxylic dianhydride, even if imidization progresses during the reaction process, the polymer is formed during the process due to its high solubility in organic polar solvents. There is no precipitation, and a uniform and transparent surface is obtained.

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 multi-layered coating thereon.

For example, semiconductors, transistors, and linear ICs.

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

,Next, 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 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, lolesterol compounds, biphenyl derivatives having optically active substituents, and phenylbenzoates are added to nematic liquid crystals. Other high-temperature coatings are used as coatings for electric wires, magnet wires, dip coatings for various electrical parts, and protective coatings for metal parts.They are also used as impregnating varnishes for coating glass cloth, fused silica cloth, graphite fibers, and boron fibers. Used for impregnation, radar domes, printed circuit boards,
Used in radioactive waste storage containers, turbine blades, spacecraft and other structural components that require high-temperature performance and excellent electrical properties.
It is also used as an interior material for waveguides in computers, 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. Also,
Glass fibers, graphite fibers, and boron fibers are added to make jet engine parts and high-strength structural molded parts.

〔Example〕

The present invention will be described in more detail below with reference to Examples.

Example 1 11.629 (0.1 mol) of hexamethylene diamine was placed in a four-necked separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet, and anhydrous N-methyl was added to this. -2-pyrrolidone was added in an amount sufficient to make the solid content ratio in all raw materials to be more than 15% by weight, and heated in an oil path to 50°C. Dry nitrogen gas was allowed to flow throughout the entire process from the preparatory stage of the reaction to the removal of the product.

Then purified anhydrous 3.3', 4.4'-benzophenonetetracarboxylic dianhydride 32.22 P (0
, 1 mol) was added little by little with stirring, but since the reaction was exothermic, the temperature of the reaction system rose to 75° C. after the addition was completed. Furthermore, it is heated using an oil path to bring the internal temperature to 8.
The temperature was set at 0° C., and the reaction was completed by stirring for 5 hours.

The product obtained is a pale yellow transparent viscous solution, with N-
The intrinsic viscosity of the 0.5% by weight solution of methyl-2-pyrrolidone was 0.48 (30°C). The same product was poured into a large amount of methanol, the precipitate was collected and dried under reduced pressure at room temperature overnight, and the IR spectrum was measured.
Strong absorption based on imide rings was observed at 1770 cm-1 and 720 crx'.

Next, a 5% solution of this polyimide fabric in N-dimethylacetamide was dropped onto a glass plate, and heated for 10 seconds at 40 Orpm using a spinner for 1500 rpm.
pm for 20 seconds to uniformly apply the coating. This was heated under reduced pressure at 80°C and 150°C for 30 minutes each, and the thickness was 1 μm.
A pale yellow transparent and tough polyimide resin film was obtained.

This film has excellent heat resistance, and the starting temperature of thermal decomposition in air was 324°C at a heating rate of 5°C/min, as measured by a differential thermal balance analyzer.

): The tensile strength of the film was 10-/-. The film also has excellent light color properties, with a light transmittance of 96% at 400°C.
Met.

Example 2 Using the same apparatus and method as in Example 1, 2,5-dimethylhexamethylenediamine 11.54f (80 mol%)
．． 4'-diaminodiphenyl ether 4. O02(2
0 mol%) and 3.3',4,4'-benzophenonetetracarboxylic dianhydride 16.111 (50 mol%)
3.3',4,4'-biphenyltetracarboxylic acid anhydride 14.71? (50 mol%) was reacted.

The resulting product is a viscous solution with an intrinsic viscosity of 0.65.
Met. The obtained film is pale yellow and transparent and has high toughness, with a thermal decomposition onset temperature of 350°C and a tensile strength of 13K.
The p/m and light transmittance were excellent at 89%.

Comparative Example 1 Using the same apparatus and method as in Example 1, pyromellitic dianhydride 21.81? (0.1 mol) and hexamethylene diamine 11.62 f (0.1 mol), the reaction system started to become cloudy after 2 hours, and the film also became cloudy and a transparent product was obtained. The tensile strength is also 3 gods/
However, it was not possible to withstand equipment rubbing work.

Comparative Example 2 Using the same apparatus and method as in Example 1, 1.16 f (10 mol) of hexamethylene diamine, 18.02 f (90 mol) of 4,4'-diaminodiphenyl ether, and 3137.4'-benzophenone tetra were prepared. Carboxylic dianhydride 16.111 (50 mol%) and 3.3',4,
4'-Biphenyltetracarboxylic dianhydride 14.71
? (50 molti) was reacted. When the IR spectrum of the obtained film was measured, imidization was not completed, and it was necessary to further heat the film at 250°C and 35°C to completely imidize it.
It was necessary to heat each sample at 0° C. for 30 minutes. Although the film thus obtained was heat resistant and tough, it had a light transmittance of only 60 inches, and could not be used as an aligned liquid crystal alignment film.

Claims (1)

[Claims] Essential components include a tetracarboxylic dianhydride component containing 5 mol% or more of 3,3',4,4'-benzophenone tetracarboxylic dianhydride and a diamine component containing 20 mol% or more of aliphatic diamine having 30 or less carbon atoms. A method for producing a heat-resistant resin, characterized in that the reaction is carried out at a temperature of 50 to 200°C.