JP2015134843A - highly transparent polyimide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide resin that is excellent in high transparency, heat resistance and low linear expansion coefficient.SOLUTION: The polyimide resin is obtained by the imidation polymerization reaction of a bicyclo[4.2.0]octane-3,4,7,8-tetracarboxylic acid dianhydride and an aromatic diamine compound so that in terms of molar ratio, with respect to 100 of the tetracarboxylic acid dianhydride, the total of the diamine compound is in the range of 90-110.

Description

  The present invention relates to a highly transparent polyimide resin.

Conventionally, polyimide resins have been widely used as resins for electronic materials because of their excellent heat resistance, strength, and electrical insulation. However, since general polyimide resins are highly colored, their use is limited.

  Therefore, research on improving the hue of polyimide resin has been conducted, and a technique using a fluorine compound as a polyimide resin raw material has been discovered (Non-Patent Document 1). However, the polyimide resin raw material having fluorine atoms is uneconomical because it is difficult to produce and expensive.

  As another method for improving the hue of a polyimide resin, studies have been conducted using an aliphatic or alicyclic compound as a polyimide resin raw material. In particular, it has been found that the use of alicyclic acid dianhydrides has a great effect on hue improvement (Non-patent Document 2).

  Transparent polyimides are especially expected for glass replacement applications. In the current flat panel display field, a technique using a glass substrate is the mainstream. Glass is a material excellent in properties such as high transparency, high heat resistance, and low linear expansion coefficient, but has a problem that it is easily broken when subjected to an impact and has a high specific gravity. Therefore, there has been a demand for the development of a polyimide excellent in flexibility that satisfies high transparency, high heat resistance, and a low linear expansion coefficient.

"Latest Trends in Revolutionary Polyimide IV-Diversified Types, Characteristics, Processability and Actual Status of Application Expansion-11th Anniversary Special Edition" Published in March 2008 Published by Sumibe Research Co., Ltd. 39 "Latest Polyimide-Basics and Applications-" Issued the first edition of the first edition on January 28, 2002 Editor Edited by Japan Polyimide Study Group Ikuo Imai, Rikio Yokota Issuer Takashi Yoshida Publisher NTS Corporation 241-242

  An object of this invention is to provide the polyimide resin excellent in high transparency, heat resistance, and a low linear expansion coefficient.

  As a result of intensive studies to solve the above problems, the present inventors have used a specific tetracarboxylic dianhydride and an aromatic diamine compound as raw materials, so that high transparency, heat resistance, and low line are achieved. As a result of finding out that a polyimide resin having an excellent expansion coefficient can be obtained and further studying it, the present invention has been completed.

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

[Claim 1]
General formula (1)
A tetracarboxylic dianhydride represented by:
A polyimide resin obtained by imidation polymerization reaction of an aromatic diamine compound with respect to the tetracarboxylic dianhydride 100 in a molar ratio within a range of 90 to 110.

[Section 2]
The aromatic diamine compound is represented by the general formula (2)
Item 2. The polyimide resin according to Item 1, which is at least one kind represented by the diamine compound.

[Section 3]
General formula (1)
A tetracarboxylic dianhydride represented by:
A polyamic acid resin obtained by copolymerizing an aromatic diamine compound with respect to the tetracarboxylic dianhydride 100 in a molar ratio within a range of 90 to 110.

[Claim 4]
The aromatic diamine compound is represented by the following general formula (2)
Item 4. The polyamic acid resin according to Item 3, which is at least one kind represented by the diamine compound.

[Section 5]
Item 5. A polyamic acid varnish containing the polyamic acid resin according to Item 3 or 4 and an organic solvent.

[Claim 6]
Item 6. A polyimide molded body obtained by molding the polyamic acid varnish according to Item 5.

[Claim 7]
Item 7. The polyimide molded body according to Item 6, wherein the polyimide molded body is in the form of a film, a film, or a sheet.

[Section 8]
Item 8. The polyimide molded article according to item 6 or 7, wherein the polyimide molded article has a linear expansion coefficient of 60 ppm / K or less, a total light transmittance of 87% or more, and a glass transition temperature of 280 ° C or more.

[Claim 9]
Item 9. A plastic substrate comprising the polyimide molded body according to any one of Items 6 to 8.

[Section 10]
Item 10. An electrical component or electronic component comprising the plastic substrate according to Item 9.

[Section 11]
Item 3. A heat-resistant insulating material, heat-resistant paint, heat-resistant coating material, or heat-resistant adhesive using the polyimide resin according to Item 1 or 2.

  ADVANTAGE OF THE INVENTION According to this invention, the polyimide resin excellent in high transparency, heat resistance, and a low linear expansion coefficient can be obtained, and the plastic substrate which consists of a molded object of the said polyimide resin can be used for an electrical component and an electronic component.

  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 of the present invention has the general formula (1)
A tetracarboxylic dianhydride represented by:
It can be obtained by carrying out an imidization polymerization reaction with an aromatic diamine compound.

(Tetracarboxylic dianhydride)
The tetracarboxylic dianhydride is a bicyclo [4.2.0] octane-3,4,7,8-tetracarboxylic dianhydride represented by the general formula (1), and is a polyimide according to the present invention. It is a constituent component of the resin.

  As a method for producing the tetracarboxylic dianhydride represented by the general formula (1), a photodimerization reaction is recommended. Specific examples include equimolar amounts of 1,2,3,6-tetrahydrophthalic anhydride and maleic anhydride in a ketone solvent such as methyl ethyl ketone, an ester solvent such as ethyl acetate, or an ether solvent such as dioxane. The tetracarboxylic dianhydride reactant can be obtained by dissolving and irradiating light of 250 to 400 nm using a high pressure mercury lamp or the like.

Tetracarboxylic dianhydrides include tetracarboxylic acids or mono, di, tri or tetra acid chlorides of tetracarboxylic acids and mono, di, tri or tetra esters of lower alcohols having 1 to 4 carbon atoms. It can also be used as a derivative.

The tetracarboxylic dianhydride 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 impaired. Other tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aliphatic tetracarboxylic dianhydrides.

  Specifically, examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, and 4,4′-oxydiphthalic acid dianhydride. Anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-di Carboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 1,1 -Bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane Two anhydrous 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 4,4 ′-(p-phenylenedioxy) diphthalic dianhydride, 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2-ethylenebis (anhydrotrimellitate), 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro- 2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1.3-dione and derivatives thereof are exemplified.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl- 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6- Tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1 , 2-dicarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and derivatives thereof.

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

  Said other tetracarboxylic dianhydride can be used for the imidation polymerization reaction alone or in combination of two or more.

  When a part of the tetracarboxylic dianhydride is used in place of the other tetracarboxylic dianhydrides, the amount used is preferably 20 with respect to the total number of tetracarboxylic dianhydrides. A mol% or less, more preferably 10 mol% or less, particularly 5 mol% or less is recommended.

(Aromatic diamine compound)
The aromatic diamine compound is a constituent component of the polyimide resin of the present invention. There is no restriction | limiting in particular in an aromatic diamine compound, The thing obtained by a commercial item or a conventionally well-known manufacturing method can be used.

Specific examples of the aromatic diamine compound include 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-amino Phenoxy) benzene, 1,3-bis (3-aminophenoxy) Benzene, bis [4- (4-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, 9,9-bis (4-aminophenyl) fluorene, O-tolidine, m-tolidine and the like. Among these, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′- Diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 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- (4-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. As a particularly preferred diamine compound, a diamine compound represented by the following general formula (2) is exemplified. These aromatic diamine compounds may be used alone or in combination of two or more.

The aromatic diamine compound can be used by replacing a part thereof with another diamine compound as long as the effect of the present invention is not hindered. Other diamine compounds include alicyclic diamine compounds and aliphatic diamine compounds.

Specific examples of the alicyclic diamine compound include diaminocyclohexane, diaminodicyclohexylmethane, dimethyl-diaminodicyclohexylmethane, tetramethyl-diaminodicyclohexylmethane, diaminodicyclohexylpropane, diaminobicyclo [2.2.1] heptane, bis (aminomethyl). ) -Bicyclo [2.2.1] heptane, 3 (4), 8 (9) -bis (aminomethyl) tricyclo [5.2.1.0 ^2,6 ] decane, 1,3-bisaminomethylcyclohexane And isophoronediamine. Among these, diaminocyclohexane, diaminodicyclohexylmethane, dimethyl-diaminodicyclohexylmethane, diaminobicyclo [2.2.1] heptane, bis (aminomethyl) -bicyclo [2.2.1] heptane, 3 (4), 8 (9) -Bis (aminomethyl) tricyclo [5.2.1.0 ^2,6 ] decane, 1,3-bisaminomethylcyclohexane, isophoronediamine and the like are exemplified.

Specific examples of the aliphatic diamine compound include ethylene diamine, hexamethylene diamine, octamethylene diamine, and decamethylene diamine.

  Said alicyclic diamine compound and aliphatic diamine compound can be used alone or in combination of two or more for the imidation polymerization reaction.

  When a part of the aromatic diamine compound is replaced with the other diamine compound, the amount used is preferably 20 mol% or less, more preferably 10 mol%, based on the number of moles of the total diamine compound. Hereinafter, 5 mol% or less is particularly recommended.

The molar ratio in the imidation polymerization reaction according to the present invention is in the range of all diamine compounds 90 to 110, more preferably in the range of 95 to 105, with respect to all tetracarboxylic dianhydrides 100. More preferably, it is the range of 98-102. By performing the imidization polymerization reaction within this range, a polyimide resin having a sufficient degree of polymerization can be obtained.

  In the present specification and claims, the diamine compound 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, an amino group is substituted for them. A compound obtained by converting part or all into an isocyanate group, a silylated compound, or the like can be used.

[Polyamide acid resin]
The polyamic acid resin which is a polyimide resin precursor according to the present invention is obtained by copolymerizing the above-described tetracarboxylic dianhydride and diamine compound in a reaction solvent in a temperature range of 5 ° C to 100 ° C.

(Reaction solvent)
The reaction solvent used in the copolymerization reaction may be any reaction solvent as long as it can dissolve the polyamic acid resin produced from the copolymerization 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-dimethylformamide, N, N-dimethylacetamide, 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-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, and γ-butyrolactone are particularly recommended.

  The amount of the reaction solvent used may be an amount that can dissolve the produced polyamic acid resin. The specific concentration of the polyamic acid resin is preferably adjusted to 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 polyamic acid varnish, but is preferably the same in consideration of the complexity of the solvent replacement operation.

  The inside of the copolymerization reaction system is preferably 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 copolymerization reaction of the polyamic acid resin according to the present invention, a salt generation inhibitor can be used. The salt generation inhibitor is preferably removable by volatilization when the polyamic acid resin varnish is heated to imidize.

  As the salt generation inhibitor, for example, a general silylating agent can be used. Silazane and the like are exemplified.

The reaction time for the copolymerization reaction of the polyamic acid resin is usually preferably about 2 to 24 hours, although it depends on the charging ratio and the substrate concentration. When reaction time is too short, the tendency for a polymerization degree to become low is recognized. If the reaction time is too long, the amide group part may partially undergo a hydrolysis reaction and the degree of polymerization may decrease.

The number average molecular weight of the polyamic acid resin 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 100,000, and the weight average molecular weight. Is 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 the present specification and claims, the molecular weight of the polyamic acid resin is a value measured by the method described in the example of the later operation.

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

  Among the methods for producing the polyimide resin, the thermal imidation method (3) is industrially preferable. For example, the polyamic acid resin is heated in a temperature range of 300 to 350 ° C., so that the generated water accompanying the imidization reaction is retained. The method of leaving and imidating polymerization reaction is mentioned.

  The imidation ratio in the heat imidization reaction of the polyamic acid resin (3) 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.

[Polyamide acid varnish]
The polyamic acid varnish of the present invention contains a polyamic acid resin and an organic solvent.

The viscosity of the polyamic acid varnish can be appropriately selected depending on the desired application, but the viscosity at 25 ° C. is preferably in the range of 0.1 to 500 Pa · s, more preferably in the range of 1 to 100 Pa · s. The

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

  Moreover, when obtaining the coating film of a polyimide resin from a polyamic-acid 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 polyamic-acid varnish which is a polyimide resin precursor 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.

[Polyimide molded product]
The polyimide molded body of the present invention is obtained by molding an amic acid varnish. As a method for molding, a conventionally known method can be used without any particular limitation.
For example, after applying the polyamic acid varnish to a substrate (after coating or forming into a film, film, or sheet), the polyamic acid varnish is dried to 200 ° C. or higher, preferably 300 ° C. or higher, and heated imide Examples thereof include a method of forming a film-like, film-like or sheet-like polyimide molded body by removing the solvent while forming.

As an example of producing a polyimide molded body, a polyamic acid varnish is cast on a PET substrate (polyethylene terephthalate substrate), and is placed in a vacuum dryer (decompression degree 1 to 10 mmHg) at room temperature for 30 minutes to 2 hours, and further about 200. The temperature is raised to 30 ° C. in 30 minutes to 2 hours, and the solvent is distilled off at that temperature for 1 to 4 hours. After cooling to room temperature, the polyimide film formed on the PET substrate is taken out from the vacuum dryer and peeled off from the PET substrate. The peeled polyamic acid film is fixed to a stainless steel metal frame, heated again from room temperature to 230 to 330 ° C in 1 to 4 hours in a vacuum dryer, and dried at that temperature for 2 to 5 hours to completely remove the solvent. The polyimide film can be obtained by removing from the vacuum dryer after cooling to room temperature. 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 range of the linear expansion coefficient of the polyimide resin of the present invention is preferably 60 ppm / K or less, more preferably 56 ppm / K or less, and particularly preferably 52 ppm / K or less. The linear expansion coefficient is a value obtained by the method described in Examples described later in the present specification and claims. For example, the range of the above linear expansion coefficient is an effective range particularly for the use of a transparent flexible substrate such as an organic EL.

  The transparency of the polyimide resin of the present invention can be evaluated by the total light transmittance. The range of the total light transmittance is preferably 87% or more, more preferably 88% or more, and particularly preferably 89% or more. The total light transmittance is a value obtained by the method described in Examples described later in this specification and claims. For example, the above range of the total light transmittance is an effective range particularly in applications requiring high transparency.

  The heat resistance of the polyimide resin of the present invention can be evaluated by the glass transition temperature. The range of the glass transition temperature is preferably 280 ° C. or higher, more preferably 290 ° C. or higher, and particularly preferably 300 ° C. or higher. The glass transition temperature is a value obtained by the method described in Examples described later in the present specification and claims. For example, the above glass transition temperature range is an effective range particularly in applications requiring heat resistance.

[Plastic substrates / Electric and electronic components]
The plastic substrate of the present invention is characterized by comprising the polyimide molded body. As the manufacturing method, a conventionally known manufacturing method can be used.

  The plastic substrate is suitably used for, for example, a flexible transparent substrate because the polyimide molded body of the present invention has high transparency, heat resistance and a low coefficient of linear expansion.

  Moreover, many flexible transparent substrates are used by an electrical component or an electronic component, for example, are used suitably as components, such as electronic paper, an organic solar cell, organic EL lighting, and a flexible liquid crystal display.

[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 transparency, heat resistance and a low linear expansion coefficient.

  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>
[Tetracarboxylic dianhydride (A)]
BCODA: Bicyclo [4.2.0] octane-3,4,7,8-tetracarboxylic dianhydride DSDA: 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride [aromatic diamine Compound (B)]
DPE: 4,4′-diaminodiphenyl ether DAM: 4,4′-diaminodiphenylmethane BAPS: bis [4- (4-aminophenoxy) phenyl] sulfone BAPB: 4,4′-bis (4-aminophenoxy) biphenyl TPE— Q: 1,4-bis (4-aminophenoxy) benzene m-TD: m-tolidine [reaction solvent]
NMP: N-methyl-2-pyrrolidone

<Number average molecular weight and weight average molecular weight of polyamic acid resin>
About 1 g of a polyamic acid resin reaction solution (polyamic acid 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

<Linear expansion coefficient>
In accordance with JIS K7197 (1991), the polyimide film (40 μm) was heated in a normal air dryer at 300 ° C. for 30 minutes for stress relaxation treatment. 4.0 × 10.0 mm cut out from this film was used in a range of 100 to 150 ° C. under the conditions of a nitrogen flow rate of 200 ml / min and a temperature increase rate of 10 ° C./min using TMA / SS6100 manufactured by SII Nano Technology. The average value of the measured values was taken as the linear expansion coefficient.

<Total light transmittance>
Compliant with JIS K7361-1 (1997 years), polyimide film (40 [mu] m) using a Toyo Seiki Seisakusho HAZE-GUARD II _Ltd., was measured by single beam method using illuminant _{D 65.}

<Glass transition temperature>
Using a dynamic viscoelasticity measuring device RHEOGEL-E4000 (manufactured by UPM), tan δ of the polyimide molded body (film) was measured under the following measurement conditions. The maximum value of tan δ was defined as the glass transition temperature (° C.).
Measurement condition;
Measurement mode: Tensile mode Sine wave: 10 Hz
Temperature increase rate: 5 ° C / min
Air flow rate: 10L / min

<Mechanical property evaluation>
The “elastic modulus”, “strength”, and “elongation” of the polyimide molded body (film) were measured according to JIS K-7161 (1994) using an universal material testing machine 5565 manufactured by Instron.

[Production example]
BCODA was produced with reference to US Pat. No. 3,234,431. Specifically, 37.0 g (377 mmol) of maleic anhydride and 1,2,3,6-tetrahydrophthalic anhydride (New Japan) were added to a 700 ml internal irradiation type Pyrex (registered trademark) glass five-necked reaction flask. 60.0 g (394 mmol) of Rikacid TH) manufactured by Rika Co., Ltd., 5.0 g (27 mmol) of benzophenone and 375 g of methyl ethyl ketone as photosensitizers were charged, and the reactor was stirred and dissolved at room temperature while covering the outer wall of the reactor with aluminum foil. Further, argon gas was bubbled for 15 minutes to remove oxygen in the reaction vessel. Subsequently, the reaction vessel was cooled to 20 ° C. while stirring, and light irradiation was continued for 24 hours using a 100 W high-pressure mercury lamp in a light source cooling tube at the center of the flask. After completion of the reaction, 4.7 g (19 mmol, yield 5%) of DCODA crystals was obtained by filtration.

[Example 1]
To a 200 mL Erlenmeyer flask equipped with a stirrer, 136 g of NMP and 11.04 g (52 mol) of m-TD as an aromatic diamine compound were added and stirred for 15 minutes. After adding 13.01 g (52 mmol) of BCODA to the resulting solution, the mixture was stirred overnight to obtain the polyamic acid varnish of the present invention. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 2]
A polyamic acid varnish of the present invention was obtained in the same manner as in Example 1 except that the aromatic diamine compound was changed to 10.41 g (52 mmol) of DPE. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 3]
A polyamic acid varnish of the present invention was obtained in the same manner as in Example 1 except that the aromatic diamine compound was changed to 15.20 g (52 mmol) of TPE-Q. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 4]
A polyamic acid varnish of the present invention was obtained in the same manner as in Example 1 except that the aromatic diamine compound was changed to 19.16 g (52 mmol) of BAPB. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 5]
A polyamic acid varnish of the present invention was obtained in the same manner as in Example 1, except that the aromatic diamine compound was changed to 22.49 g (52 mmol) of BAPS. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 6]
A polyamic acid varnish of the present invention was obtained in the same manner as in Example 1 except that the aromatic diamine compound was changed to 10.31 g (52 mmol) of DAM. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Comparative Example 1]
A polyamic acid varnish was obtained in the same manner as in Example 2 except that the tetracarboxylic dianhydride was changed from BCODA to 18.63 g (52 mol) of DSDA. The measurement results of the average molecular weight of the obtained polyamic acid varnish are shown in Table 1.

[Example 7]
The polyamic acid varnish obtained in Examples 1 to 6 was applied onto a glass substrate using a bar coater so that the dry film thickness was 40 μm, and was vacuumed in a vacuum dryer (decompression degree: 10 mmHg or less) at 300 ° C. * It dried for 1 hour, and after making it cool to room temperature, it was made to peel from a glass substrate, and the polyimide molding (film) was obtained. Table 1 shows the measurement results of the linear expansion coefficient, total light transmittance, glass transition temperature, and mechanical properties of the obtained polyimide molded body (film).

[Comparative Example 2]
A polyimide molded body (film) was obtained from the polyamic acid varnish obtained in Comparative Example 1 in the same manner as in Example 13. Table 1 shows the measurement results of the linear expansion coefficient, total light transmittance, glass transition temperature, and mechanical properties of the obtained polyimide molded body (film).

From Table 1, it is clear that the polyimide resin of the present invention has excellent physical properties such as a low linear expansion coefficient of 60 ppm / K or less, a high total light transmittance of 87% or more, and a high glass transition temperature of 280 ° C. or more. It is. It is clear that the polyimide resin of Comparative Example 1 has a low total light transmittance.

  The polyimide resin of the present invention has both high transparency, heat resistance and a low coefficient of linear expansion. Therefore, the polyimide molded body obtained by molding the polyamic acid varnish of the present invention can be suitably used for optical materials such as displays and lighting. In addition, the polyimide resin can be used for heat-resistant insulating materials, heat-resistant paints, heat-resistant coating materials, and heat-resistant adhesives.

Claims (11)

General formula (1)
A tetracarboxylic dianhydride represented by:
A polyimide resin obtained by imidation polymerization reaction of an aromatic diamine compound with respect to the tetracarboxylic dianhydride 100 in a molar ratio within a range of 90 to 110. The aromatic diamine compound is represented by the general formula (2)
The polyimide resin of Claim 1 which is at least 1 sort (s) represented by the diamine compound. General formula (1)
A tetracarboxylic dianhydride represented by:
A polyamic acid resin obtained by copolymerizing an aromatic diamine compound with respect to the tetracarboxylic dianhydride 100 in a molar ratio within a range of 90 to 110. The aromatic diamine compound is represented by the following general formula (2)
The polyamic acid resin according to claim 3, which is at least one kind represented by a diamine compound. A polyamic acid varnish containing the polyamic acid resin according to claim 3 or 4 and an organic solvent. A polyimide molded body obtained by molding the polyamic acid varnish according to claim 5. The polyimide molded body according to claim 6, wherein the polyimide molded body is in the form of a film, a film, or a sheet. The polyimide molded body according to claim 6 or 7, wherein the polyimide molded body has a linear expansion coefficient of 60 ppm / K or lower, a total light transmittance of 87% or higher, and a glass transition temperature of 280 ° C or higher. The plastic substrate which consists of a polyimide molded body in any one of Claims 6-8. An electrical component or electronic component comprising the plastic substrate according to claim 9. A heat-resistant insulating material, heat-resistant paint, heat-resistant coating material, or heat-resistant adhesive using the polyimide resin according to claim 1.