JP5966966B2 - High heat resistance polyimide resin - Google Patents

Description

The present invention relates to a high heat resistant polyimide resin.

Conventionally, as a polyimide base film for heat-resistant insulating materials, especially electronic materials represented by flexible printed circuit boards called FCCL, heat-resistant materials represented by a condensate of pyromellitic acid and diaminodiphenyl ether (trade name Kapton) Polyimide resins with temperatures above 400 ° C. have been used. However, this type of highly heat-resistant polyimide is often insoluble in solvents, and in actual use, the precursor is amic acid varnish and the coating is heated to a temperature of 350 ° C. or higher, for example. The method of performing imidization reaction has been taken. Further, such an amic acid type has poor storage stability and is accompanied by a decrease in viscosity over time at room temperature storage, and thus has storage problems such as requiring refrigeration or freezing storage.

Moreover, in order to obtain a polyimide molded body from a conventional amic acid varnish, it is necessary to subject the amic acid dissolved in a special solvent to a dehydration imidization reaction at a high temperature, which requires special production equipment.

Many solvent-soluble polyimide resins have been proposed in place of the polyamic acid varnish. For example, a polyimide containing a diamine having a fluorene skeleton as a constituent component is disclosed (Patent Documents 1-6). For example, Patent Document 1 discloses a polyimide resin having a glass transition point of 250 ° C. or higher, which is soluble in an organic solvent, and has a diamine having a fluorene skeleton as its component, as a resin for a plate material. Patent Documents 2-5 also filed application patents focusing on the heat resistance and solvent solubility of polyimides having fluorene-based diamines as in Patent Document 1.

However, even with the polyimide resins described in these patent documents, the glass transition temperature and the decomposition temperature of the resin are low compared to the polyimide resin obtained from the conventional polyamic acid varnish, and the storage stability of the polyimide resin solution is also high. It is not always satisfactory. Thus, in general, heat resistance and solvent solubility are contradictory properties, a polyimide resin having a glass transition temperature exceeding 400 ° C. and a decomposition temperature of resin exceeding 500 ° C. and excellent in solvent solubility. Is not known.

In recent years, in the automobile and aircraft industries, heat-resistant members such as insulating heat shields for special distribution boards and protective films in turbines are often used. What is used in a high temperature region of 400 ° C. is increasing. Moreover, what can endure 400 degreeC is requested | required as a heat insulating material of an electric furnace or a drying furnace. In these applications, the conventional solvent-soluble polyimide resin does not always satisfy the glass transition temperature and the decomposition temperature of the resin. Therefore, a polyimide resin having a glass transition temperature exceeding 400 ° C. and a decomposition temperature of resin exceeding 500 ° C. and excellent in solvent solubility has been demanded.

JP 2005-289034 A JP 2000-008020 A JP 2003-051210 A JP 2005-262529 A Japanese Patent Laid-Open No. 11-212097 JP 2005-325332 A

An object of the present invention is to provide a polyimide resin that is excellent in solvent solubility while having a glass transition temperature exceeding 400 ° C. and a decomposition temperature of resin exceeding 500 ° C., which have been considered difficult in the past.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that a polyimide resin obtained from two specific tetracarboxylic dianhydrides and a specific diamine component has a glass transition temperature exceeding 400 ° C and It has been found that the resin has a decomposition temperature exceeding 500 ° C. and is excellent in solvent solubility. Furthermore, as a result of examining the molar ratio of the two types of tetracarboxylic dianhydrides, it was found that it can be used as a polyimide molded body (film) within a specific molar ratio range, and the present invention has been completed.

That is, the present invention provides the following polyimide resins.

[Claim 1]
Tetracarboxylic of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (A) and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (B) in the presence of a reaction solvent Acid dianhydride,
Fluorene skeleton diamine (C) represented by the following general formula (1):
The molar ratio of (A) and (B) is in the range of (A) :( B) = 40: 60 to 80:20, and (C) with respect to the total moles of (A) and (B) Is a polyimide resin obtained by imidation polymerization reaction at a molar ratio in the range of 90 to 110.
[Wherein, R ¹ and R ² are the same or different and each represents hydrogen, a methyl group, an ethyl group, fluorine, or chlorine. ]

[Section 2]
Item 5. A polyimide varnish containing the polyimide resin according to item 1 and an organic solvent.

[Section 3]
The organic solvent is at least one organic solvent selected from the group consisting of N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone and γ-butyrolactone. Item 3. The polyimide varnish according to Item 2.

[Claim 4]
Item 4. The polyimide varnish according to Item 2 or Item 3, which is for an insulating material, a heat-resistant paint, a heat-resistant coating material, a heat-resistant adhesive, or a heat-resistant binder.

[Section 5]
Item 5. A polyimide molded body obtained by molding the polyimide varnish according to Item 2 or Item 3.

[Claim 6]
Item 6. The polyimide molded body according to Item 5, wherein the polyimide molded body is in the form of a film, a film, or a sheet.

[Claim 7]
A heat-resistant insulating material, heat-resistant paint, heat-resistant coating material, or heat-resistant adhesive using the polyimide resin according to Item 1.

According to the present invention, it is possible to obtain a polyimide resin having extremely high heat resistance, which is soluble in a solvent and has a glass transition temperature exceeding 400 ° C. and a decomposition temperature of the resin exceeding 500 ° C. Furthermore, since the polyimide resin varnish does not require heating imidization, it is excellent in workability, and the resulting polyimide molded body can be used for insulating materials, heat-resistant paints, heat-resistant coating materials, heat-resistant adhesives, heat-resistant binders, etc. Preferably used.

In addition, the polyimide resin can be used for heat-resistant insulating materials, heat-resistant paints, heat-resistant coating materials, and heat-resistant adhesives.

[Polyimide resin]
The polyimide resin composition of the present invention comprises 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (hereinafter abbreviated as component (A)) and 3,3 ′, 4,4 ′. -Tetracarboxylic dianhydride of biphenyltetracarboxylic dianhydride (hereinafter abbreviated as (B) component), and fluorene skeleton diamine (hereinafter referred to as (C) component) represented by the above general formula (1) Is a polyimide resin obtained by imidization polymerization reaction.

[Tetracarboxylic dianhydride: component (A) and component (B)]
The component (A) and the component (B) which are constituent components of the polyimide resin according to the present invention are not particularly limited, and commercially available products or those obtained by a conventionally known production method can be used.

The molar ratio of the component (A) and the component (B) is in the range of (A) :( B) = 40: 60 to 80:20, preferably in the range of 55:45 to 75:25. . The polyimide resin of the present invention obtained in this range can be obtained as a polyimide resin which is soluble in a solvent and has a very high glass transition temperature and resin decomposition temperature and can be used as a molded body (film). When the molar ratio of the component (A) is less than 40 (the molar ratio of the component (B) is more than 60), the polyimide resin cannot be used as a molded body (film), and the molar ratio of the component (B) Is less than 20 (the molar ratio of the component (A) is more than 80), the glass transition temperature is lower than 400 ° C and the decomposition temperature of the resin is lower than 500 ° C.

In addition, the component (A) or the component (B) can be used by replacing a part of the tetracarboxylic dianhydride with another tetracarboxylic dianhydride as long as the effects of the present invention are not hindered. . Other tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, or alicyclic tetracarboxylic dianhydrides.

Specifically, examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4′-oxydiphthalic anhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride. 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic acid Dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4 -Dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) Diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 2,3 ′, 3,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4, 4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, 1,2-ethylenebis (anhydrotrimellitate), 1,3-propylenebis (anhydrotritriate) Meritate), 1,4-tetramethylene bis (anhydro trimellitate), 1,5-pentamethylene bis (anhydro trimellitate), , 6-hexamethylene-bis (anhydrotrimellitate), 1,3-phenylene bis (anhydrotrimellitate), 1,4-phenylene bis (anhydrotrimellitate) and the like.

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and 1,2,4,5-pentanetetracarboxylic dianhydride.

In addition, as alicyclic tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2-acetic acid dianhydride 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, bicyclo [2.2.1] -heptane-2,3,5 6-tetracarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, etc., bicyclo [2.2.2] -octene -2, 3, 5, 6 Tetracarboxylic dianhydride, and the like.

Said other tetracarboxylic dianhydride can be used for imidation polymerization reaction individually or in mixture of 2 or more types.

When a part of the component (A) or the component (B) is replaced with the other tetracarboxylic dianhydride, the amount used is the total number of moles of the component (A) and the component (B). On the other hand, 10 mol% or less, more preferably 5 mol% or less, particularly 1 mol% or less is recommended.

In the present specification and claims, tetracarboxylic dianhydride is described in the form of “tetracarboxylic dianhydride”, but instead, various derivatives shown below are used for imidation polymerization reaction. Can be provided. For example, the tetracarboxylic acid which is a derivative of the tetracarboxylic dianhydride, the acid chloride of the tetracarboxylic acid, the tetracarboxylic acid, a lower alcohol and ester having 1 to 4 carbon atoms, and the like can be mentioned.

[Fluorene skeleton diamine: component (C)]
There is no restriction | limiting in particular as (C) component represented by the said General formula (1) which is a structural component of the polyimide resin which concerns on this invention, The thing obtained by a commercial item or a conventionally well-known manufacturing method can be used.

Among the components (C) represented by the general formula (1), R ¹ and R ² are the same or different and each is hydrogen, methyl group, ethyl group, fluorine or chlorine. Can be mentioned.

Specific examples of such component (C) include 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (2-methyl-4-aminophenyl) fluorene, 9,9-bis (3 -Methyl-4-aminophenyl) fluorene, 9,9-bis (2-ethyl-4-aminophenyl) fluorene, 9,9-bis (3-ethyl-4-aminophenyl) fluorene, 9,9-bis ( 2-Fluoro-4-aminophenyl) fluorene, 9,9-bis (3-fluoro-4-aminophenyl) fluorene, 9,9-bis (2-chloro-4-aminophenyl) fluorene, 9,9-bis (3-chloro-4-aminophenyl) fluorene and the like are exemplified. These components (C) may be used alone or in combination of two or more.

Among these, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (3-methyl-4-aminophenyl) fluorene, 9,9-bis (3-ethyl-4-aminophenyl) fluorene 9,9-bis (3-fluoro-4-aminophenyl) fluorene, 9,9-bis (3-chloro-4-aminophenyl) fluorene are recommended, especially 9,9-bis (4-aminophenyl) Fluorene is recommended.

Further, the component (C) can be used by replacing a part of the diamine with another diamine as long as the effects of the present invention are not hindered.

Specifically, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3 , 3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl Sulfide, 3,3′-diaminodiphenyl sulfide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [ -(4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4 -(3-aminophenoxy) phenyl] propane, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl ] Ether, bis [4- (3-aminophenoxy) phenyl] ether, o-tolidine, m-tolidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 2,7-diamino -3,6-dimethyl-9-thiafluorene-9,9-dioxide, 2,7-diamino-1,6-dimethyl-9-thiafluorene-9,9-di Aromatic diamines such as xoxide, hexamethylenediamine, octamethylenediamine, decamethylenediamine, diaminocyclohexane, diaminodicyclohexylmethane, diaminodicyclohexylpropane, diaminobicyclo [2.2.1] heptane, bis (aminomethyl) -bicyclo [2 2.1] Aliphatic or alicyclic diamines such as heptane are exemplified.

These diamines can be used alone or in combination of two or more for the imidation polymerization reaction.

When a part of the component (C) is replaced with the other diamine, the amount used is preferably 10 mol% or less, more preferably 5 mol%, relative to the number of moles of the component (C). Hereinafter, 1 mol% or less is particularly recommended.

In the present specification and claims, the diamine is described in the form of “diamine”. However, as long as the effect of the present invention is obtained for the purpose of improving the reactivity, a part of the amino group is used instead. Alternatively, it is possible to use a compound in which all are converted to an isocyanate group, a silylated compound, or the like.

(Reaction solvent)
The reaction solvent used in the imidation polymerization reaction according to the present invention may be any reaction solvent as long as it can dissolve the polyimide resin produced from the imidization polymerization reaction. For example, preferred examples include aprotic solvents, phenol solvents, ether solvents, carbonate solvents, and the like.

Specific examples of the aprotic solvent include N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea and the like. Amide solvents, lactone solvents such as γ-butyrolactone and γ-valerolactone, phosphorus-containing amide solvents such as hexamethylphosphoric amide and hexamethylphosphine triamide, sulfur-containing dimethylsulfone, dimethylsulfoxide, sulfolane and the like Examples thereof include a system solvent, a ketone solvent such as acetone, cyclohexane and methylcyclohexanone, an amine solvent such as picoline and pyridine, and an ester solvent such as acetic acid (2-methoxy-1-methylethyl).

Specific examples of the phenol solvent include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4 -Xylenol, 3,5-xylenol and the like are exemplified.

Specific examples of the ether solvent include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetrahydrofuran, 1,4-dioxane and the like.

Specific examples of the carbonate solvent include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, and the like. You may use said reaction solvent individually or in mixture of 2 or more types.

Among these reaction solvents, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, and γ-butyrolactone are particularly recommended.

The amount of the reaction solvent used may be an amount that can dissolve the produced polyimide resin. It is recommended that the specific polyimide resin concentration be adjusted to preferably 5 to 50% by weight, more preferably 10 to 40% by weight, and still more preferably 10 to 30% by weight.

The reaction solvent may be the same as or different from the organic solvent constituting the polyimide varnish according to the present invention, but is preferably the same in consideration of the complexity of the solvent replacement operation.

(Imidation polymerization reaction)
As a method of imidation polymerization reaction, (1) heat in which tetracarboxylic dianhydride and diamine are heated in the presence of a reaction solvent and a small amount of azeotropic solvent to distill off the produced water by azeotropic distillation. Imidization method, (2) Chemical imidization method using the dehydration action of carbodiimide compounds such as acid anhydrides such as acetic anhydride and propionic anhydride, or dicyclohexylcarbodiimide after the polyamic acid of polyimide precursor is produced, (3) polyimide Examples thereof include a thermal imidization method in which the precursor polyamic acid is produced and then heated to 300 ° C. or higher.

Among the methods for producing the polyimide resin, the thermal imidation method of (1) is industrially preferable. For example, the total amount of tetracarboxylic dianhydride and diamine is dissolved in the reaction solvent, or tetracarboxylic dianhydride and After dissolving a part of the diamine stepwise, it is preferably heated to 100 to 250 ° C., more preferably 150 to 200 ° C., and the generated water in the system is distilled off with an azeotropic solvent to carry out an imidation polymerization reaction. A method is mentioned.

Moreover, the polymer terminal of a polyimide resin can be made into an amine terminal by using diamine excessively with respect to tetracarboxylic dianhydride, On the other hand, polyimide can be used by using tetracarboxylic dianhydride more excessively than diamine. The polymer ends of the resin can be acid ends.

Examples of the azeotropic solvent for distilling the generated water out of the system include aromatic hydrocarbons such as toluene, xylene and solvent naphtha, and alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and dimethylcyclohexane. These can be used alone or as a mixed system. The amount used is usually about 1 to 30% by weight, preferably about 5 to 10% by weight, based on the amount of the reaction solvent.

The inside of the reaction system is desirably an inert gas atmosphere from the viewpoint of preventing coloration and safety of the reaction system. Usually, a method of replacing the inside of the reaction system with an inert gas and allowing the inert gas to flow during the reaction is recommended. Examples of the inert gas include nitrogen and argon.

In the imidation polymerization reaction according to the present invention, a known catalyst can be used. However, it is preferable to carry out the reaction in the absence of a catalyst from the viewpoints of complicated post-treatment, deterioration of the storage stability of the polyimide varnish due to the residual amount of catalyst used, and coloring of the polyimide varnish.

When a catalyst is used, for example, pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, trimethylamine, Organic base catalysts such as butylamine, imidazole, N, N-dimethylaniline, N, N-diethylaniline, inorganic bases represented by potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate Examples are catalysts.

Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, and the like. Is exemplified.

The reaction time of the imidation polymerization reaction is preferably about 2 to 10 hours after the start of distilling of the produced water, although it depends on the charging ratio and the substrate concentration. When reaction time is too short, the tendency for imidation ratio to become low is recognized. If the reaction time is too long, the reaction system may partially cause a thermal crosslinking reaction to thicken the reaction system or form a gel-like material, or the reaction system may be colored due to thermal degradation of the reaction solvent. .

The number average molecular weight of the polyimide resin of the present invention obtained by imidation polymerization reaction is preferably 6,000 or more, and the weight average molecular weight is 10,000 or more, more preferably the number average molecular weight is 6,000 to 100. And a weight average molecular weight in the range of 10,000 to 500,000. This range is a range having a degree of polymerization that can give a molded product. In addition, in this specification and a claim, the molecular weight of a polyimide resin is the value measured by the method described in the Example of the postoperative.

The imidation rate in the imidation polymerization reaction is usually 70% or more, preferably 80% or more, more preferably 90% or more, and particularly 95% or more. Furthermore, it may be desirable to make the imidization rate close to 100% depending on the use application of the polyimide resin.

In addition, known monofunctional acid anhydrides, monoamines and the like used in this field can be used in combination as an end cap agent for the purpose of controlling the molecular weight and the like within a range not impairing the effects of the present invention. Specific examples of the end cap agent include phthalic anhydride, maleic anhydride, nadic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. for acid anhydrides, and aniline, methylaniline, allylamine, etc. for monoamines. .

[Polyimide varnish]
The polyimide varnish of the present invention is characterized by containing a polyimide resin and an organic solvent.

As a method for preparing a polyimide varnish, (i) a method of using a reaction solvent solution of a polyimide resin obtained by an imidization polymerization reaction as it is as a polyimide varnish, (ii) a reaction solvent solution of a polyimide resin obtained by an imidization polymerization reaction Examples are a method of obtaining a polyimide varnish by isolating a polyimide resin from the following and then dissolving the isolated polyimide resin in a desired organic solvent.

Although it can select suitably as a viscosity of a polyimide varnish by a desired use, Preferably it is 0.1-500 Pa.s, More preferably, it is 1-100 Pa.s.

The concentration of the polyimide resin in the polyimide varnish is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, and further preferably 10 to 30% by weight.

The organic solvent is not particularly limited as long as it is an organic solvent capable of dissolving the polyimide resin according to the present invention, and specific examples include those exemplified as the reaction solvent. These can be used alone or as a mixed system. Among these, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, and γ-butyrolactone are recommended.

Moreover, when obtaining the coating film of a polyimide resin from a polyimide varnish, a part of organic solvent can be replaced with a low boiling point solvent for the purpose of performing a drying process efficiently. Such low boiling point solvents include aromatic hydrocarbons such as toluene, xylene, solvent naphtha, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, dimethylcyclohexane, propylene glycol monomethyl ether, or acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. The ketones are exemplified. When these low-boiling solvents are used, the amount used is preferably 1 to 30% by weight, more preferably 5 to 20% by weight, based on the total amount of organic solvent.

Moreover, you may add another component to the polyimide varnish of this invention in the range which does not inhibit the effect of this invention. For example, polyester resin, polyimide resin (excluding the polyimide resin of the present invention), polymer compound such as polyamideimide resin, polyamide resin, smoothing agent, leveling agent, defoaming agent, flame retardant, antifoaming agent, antioxidant Etc. are exemplified.

The polyimide varnish thus obtained is used for insulating materials, heat-resistant paints, heat-resistant coating materials, heat-resistant adhesives, or heat-resistant binders.

[Polyimide molded product]
The polyimide molded body of the present invention is obtained by molding the polyimide varnish. As a method for molding, a conventionally known method can be used without any particular limitation. For example, after the polyimide varnish is applied to a substrate (after being applied or formed into a film, film, or sheet), the organic solvent is removed from the polyimide varnish to form a film, film, or sheet polyimide. The method etc. which shape | mold into a molded object are illustrated.

As an example of producing a polyimide molded body, a polyimide varnish is cast on a glass substrate, and the temperature is raised from room temperature to 230 to 280 ° C. in 1 to 4 hours in a vacuum dryer (decompression degree 1 to 10 mmHg). Then, the solvent is completely distilled off, and after cooling to room temperature, the polyimide film can be obtained by taking out from the vacuum dryer. A method of adjusting the thickness of the polyimide film thus obtained to a target thickness by adjusting the coating thickness at the time of casting can be mentioned.

The heat resistance of the polyimide resin of the present invention can be evaluated by the glass transition temperature and the decomposition temperature of the resin. The glass transition temperature of the polyimide resin of the present invention is 400 ° C. or higher, and the decomposition temperature of the resin is 500 ° C. or higher. The glass transition temperature and the decomposition temperature of the resin are values obtained by the methods described in Examples described later in the present specification and claims.

[Heat-resistant insulation / heat-resistant paint / heat-resistant coating material / heat-resistant adhesive]
The heat-resistant insulating material, heat-resistant coating material, heat-resistant coating material or heat-resistant adhesive material of the present invention uses the polyimide resin of the present invention. As the manufacturing method, a conventionally known manufacturing method can be used. In any case, the polyimide resin is preferably used because it has high heat resistance.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, the measuring method of each characteristic in an Example and a comparative example and the abbreviation of a compound are as follows.

<Abbreviation of compound>
Abbreviations used in the following examples are as follows.
DSDA: 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride FDA: 9,9-bis (4-amino) Phenyl) fluorene NMP: N-methyl-2-pyrrolidone

<Number average molecular weight and weight average molecular weight of polyimide resin>
About 1 g of a polyimide resin reaction solution (polyimide varnish) is diluted with about 30 ml of N, N-dimethylformamide to prepare a sample solution for molecular weight measurement. The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were determined under the following measurement conditions using gel permeation chromatography (GPC).
[Measurement condition]
Device: EcoSEC HLC-8320GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation One SuperH-H and three SuperHM-Ms connected in series Column temperature: 40 ° C
Eluent: (5.15 mmol / L-lithium bromide + 5.10 mmol / L-phosphoric acid) / N, N-dimethylformamide Flow rate: 0.5 mL / min
Detector: RI

<Polyimide varnish resin concentration>
The resin concentration (% by weight) of the polyimide varnish was determined according to the following method. 10 mg of polyimide varnish is precisely weighed (to the second decimal place) and set in a TG-DTA device (device name manufactured by SII Nanotechnology; EXSTAR6000, TG-DTA6200) at 350 ° C. under the following measurement conditions. The weight was measured. It calculated according to the following formula (1) using the obtained measured value.
Measurement condition;
Temperature increase rate: 5 ° C / min Flowing nitrogen amount: 100ml / min Measurement start temperature: 30 ° C
(a formula)
Concentration of polyimide resin in reaction solution = (W ₁ / W ₀ ) × 100 (1)
W ₁ : Weight of measurement sample at 350 ° C. (g)
W ₀ : Weight of measurement sample before measurement (g)

<Evaluation of solvent solubility>
Solvent solubility was evaluated by visually observing the state after preparing an NMP solution of 5 wt% polyimide resin and leaving it at room temperature for 24 hours. The criteria for the evaluation are as follows. On the basis of this criterion, ◯ is excellent in solvent solubility. It becomes evaluation that x is inferior to solvent solubility. The criteria for the evaluation are as follows.
○: Neither generation of precipitate nor gelation of the reaction solution was observed even after standing for 24 hours.
X: Generation of precipitates or gelation of the reaction solution was clearly observed within 24 hours.

<Glass transition temperature>
A polyimide molded body (film, thickness 40 μm) was cut to obtain a sample for Tg measurement. A differential thermal scanning calorific value (DSC 6220) manufactured by SII Nanotechnology Co., Ltd. was used for this measurement sample, and the inflection point when the temperature was raised at a heating rate of 10 ° C. per minute was defined as the glass transition temperature.

<Decomposition temperature>
A polyimide molded body (film, thickness 40 μm) is cut, and about 10 mg is precisely weighed (to the second decimal place), TG-DTA device (product name manufactured by SII Nanotechnology Inc .; EXSTAR6000, TG-DTA6200) ), And the weight decreased by 5% from the initial weight was measured as the decomposition temperature under the following measurement conditions.
[Measurement condition]
Temperature rising rate: 10 ° C / min Flowing nitrogen amount: 200ml / min Measurement start temperature: 50 ° C

<Mechanical properties (elastic modulus, strength, elongation)>
The elastic modulus, strength and elongation at break of the polyimide molded body (film) were measured according to JISK7161 (1994) using a universal material testing machine 5565 (manufactured by Instron). First, a test piece having a thickness of 40 μm and a width of 10 mm was fixed to have a length of 50 mm, and the test piece was stretched at a speed of 10 mm / min under the conditions of 25 ° C. and RH 60%.

Example 1
DSDA (component A) 10.78 g (30.09 mmol), BPDA (component B) 3.79 g (into a 200 mL four-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, separator decanter, and condenser tube ( 12.88 mmol), FDA (C component) 14.98 g (42.999 mmol), NMP 100.8 g as a reaction solvent, 11.2 g of xylene as an azeotropic solvent, and the inside of the reaction system was purged with nitrogen, The mixture was stirred at 180 ° C., and a dehydration imidation polymerization reaction was performed for 5 hours while removing generated water out of the system. After completion of the reaction, NMP was added so that the resin concentration was 20% by weight to obtain an NMP solution of the polyimide resin of the present invention (polyimide varnish of the present invention). Table 1 shows the average molecular weight of the obtained polyimide resin and the solvent solubility measurement results.

The obtained polyimide varnish was cast on a glass plate using a glass rod with a gap adjusted appropriately by the number of windings of the tape seal so that a predetermined thickness (40 μm) was obtained after the predetermined solvent was distilled off. Subsequently, it was dried with hot air at 300 ° C. for 1 hour under normal pressure under a nitrogen stream. It cooled to room temperature and peeled from the glass plate, and the polyimide molded body (film, 40 micrometers) was obtained. Using the polyimide molded body, the glass transition temperature decomposition temperature and mechanical properties were measured. The results are shown in Table 1.

(Example 2)
Except for changing the ratio of DSDA (component A) 7.85 g (21.91 mmol), BPDA (component B) 6.45 g (21.92 mmol), FDA (component C) 15.27 g (43.82 mmol) A polyimide varnish and a polyimide molded body of the present invention were obtained in the same manner as in Example 1. Table 1 shows the measurement results of average molecular weight, solvent solubility, resin concentration, glass transition temperature, decomposition temperature, and mechanical properties.

(Comparative Example 1)
Example 1 except that DSDA (component A) was changed to 13.59 g (37.93 mmol), BPDA (component B) 1.24 g (4.21 mmol), and FDA (component C) 14.69 g (42.16 mmol). In the same manner as above, a polyimide varnish and a polyimide molded body were obtained. Table 1 shows the measurement results of average molecular weight, solvent solubility, resin concentration, glass transition temperature, decomposition temperature, and mechanical properties.

(Comparative Example 2)
DSDA (component A) 1.20 g (3.35 mmol), BPDA (component B) 2.30 g (7.82 mmol), FDA (component C) 3.90 g (11.19 mmol) NMP 119.7 g as a reaction solvent, azeotropic After charging 13.3 g of xylene as a solvent and substituting the inside of the reaction system with nitrogen, the mixture was stirred at 180 ° C. under a nitrogen stream, and a dehydration imidation polymerization reaction was performed for 20 hours while removing generated water out of the system. After completion of the reaction, NMP was added so that the resin concentration was 5% by weight to obtain a polyimide varnish. Table 1 shows the average molecular weight of the obtained polyimide resin and the solvent solubility measurement results.

The obtained polyimide varnish was cast on a glass plate using a glass rod whose gap was appropriately adjusted with the number of windings of the tape seal so that a predetermined thickness was obtained after the predetermined solvent was distilled off. Subsequently, it was dried with hot air at 300 ° C. for 1 hour under normal pressure under a nitrogen stream, and then cooled to room temperature. The obtained polyimide molded body (film) was very brittle and the mechanical properties could not be measured, but the glass transition temperature and the decomposition temperature were measured. The results are shown in Table 1.

(Comparative Example 3)
A polyimide varnish and a polyimide molded body were obtained in the same manner as in Example 1 except that DSDA (component A) was changed to 14.96 g (41.76 mmol) and FDA (component C) was 14.55 g (41.76 mmol). . Table 1 shows the measurement results of average molecular weight, solvent solubility, resin concentration, glass transition temperature, decomposition temperature, and mechanical properties.

(Comparative Example 4)
In place of DSDA (component A), BPDA (component B) 3.40 g (11.56 mmol), FDA (component C) was changed to 4.02 g (11.54 mmol), and the same method as in Comparative Example 2 When the imidization reaction was performed, the reaction system gelled, and thus a solvent-soluble polyimide resin composition could not be obtained.

From Table 1, it can be seen that in Comparative Example 1 and Comparative Example 3, the glass transition temperature is as low as 400 ° C. or lower and the decomposition temperature is as low as 500 ° C. or lower. In Comparative Example 2, the glass transition temperature and the decomposition temperature are satisfied, but the polyimide molded body (film) is brittle and cannot be used as a molded body (film). Moreover, in the comparative example 4, it turns out that solvent solubility is inadequate.

It is clear from Table 1 that the polyimide resin of the present invention is a polyimide resin having solvent solubility, has excellent physical properties of a glass transition temperature of 400 ° C. or higher and a decomposition temperature of 500 ° C. or higher, and can be used as a molded body (film). It is.

According to the present invention, a polyimide varnish having an extremely high glass transition temperature of 400 ° C. or higher and a resin decomposition temperature of 500 ° C. or higher, solvent solubility and excellent storage stability can be obtained, and a heating imidization step at a high temperature is required. In addition, a highly heat-resistant insulating film, heat-resistant coating film, heat-resistant coating and the like can be performed only by coating and drying.

Claims (7)

Tetracarboxylic of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (A) and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (B) in the presence of a reaction solvent Acid dianhydride,
Fluorene skeleton diamine (C) represented by the following general formula (1):
The molar ratio of (A) and (B) is in the range of (A) :( B) = 40: 60 to 80:20, and (C) with respect to the total moles of (A) and (B) Is a polyimide resin obtained by imidation polymerization reaction at a molar ratio in the range of 90 to 110.
[Wherein, R ¹ and R ² are the same or different and each represents hydrogen, a methyl group, an ethyl group, fluorine, or chlorine. ] A polyimide varnish containing the polyimide resin according to claim 1 and an organic solvent. The organic solvent is at least one organic solvent selected from the group consisting of N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone and γ-butyrolactone. The polyimide varnish according to claim 2, wherein The polyimide varnish according to claim 2 or 3, which is for an insulating material, a heat resistant paint, a heat resistant coating material, a heat resistant adhesive or a heat resistant binder. A polyimide molded body obtained by molding the polyimide varnish according to claim 2. The polyimide molded body according to claim 5, wherein the polyimide molded body is in the form of a film, a film, or a sheet. A heat-resistant insulating material, heat-resistant paint, heat-resistant coating material, or heat-resistant adhesive using the polyimide resin according to claim 1.