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Polyimide powder, polyimide varnish and polyimide film

A technology of polyimide powder and polyimide, which is applied in the field of polyimide varnish, polyimide film and polyimide powder, and can solve the problem of reducing the mechanical properties of polyimide film, polyimide Achieve excellent heat resistance, mechanical properties, and excellent transparency due to problems such as changes in the viscosity of imine varnishes and changes in the degree of polymerization of polyamic acid

Active Publication Date: 2020-05-08
KAWAMURA SANGYO KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, the polyimide powders described in Patent Document 3 and Patent Document 4 are produced via polyamic acid obtained by polymerizing diamines and acid anhydrides in substantially the same molar amount as raw material monomers. , in the case of this production method, the polymerization degree of polyamic acid will vary greatly due to slight monomer weighing errors, monomer dissolution residues, monomer purity fluctuations, etc., resulting in the presence of polyimide obtained Unstable polymerization degree of amine powder
In order to prevent this, a method of polymerizing polyamic acid with the molar ratio of diamine and acid anhydride slightly deviated from 1 is adopted, but even in this case, the degree of polymerization is affected by the amount of water contained in the solvent. The problem of changes due to the influence of
In addition, in the stage of polyamic acid solution, even if it is a solution with the same degree of polymerization, the degree of polymerization may change due to the cracking of the polymer in the subsequent imidization, powderization, drying and other processes. question
[0006] It can be seen that when the polyimide powder whose degree of polymerization changes is directly dissolved in a solvent and used as a polyimide solution (varnish), there is a problem that the viscosity of the polyimide varnish changes significantly and cannot While forming a stable polyimide film, the mechanical properties of the resulting polyimide film may decrease

Method used

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  • Polyimide powder, polyimide varnish and polyimide film
  • Polyimide powder, polyimide varnish and polyimide film

Examples

Experimental program
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Effect test

Embodiment

[0094] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0095] (Measurement method of reduced viscosity of polyimide)

[0096] The polyimide powder was dissolved in N,N-dimethylacetamide (DMAC) at a concentration of 0.5 g / dL to prepare a polyimide solution. The outflow time (T) of the polyimide solution and the outflow time (T0) of only the solvent DMAC were measured at a temperature of 30° C. using an Ubbelohde viscometer, and the reduced viscosity was obtained from the following formula.

[0097] Reduced viscosity (dL / g) = (T-T0) / T0 / 0.5

[0098] (Measurement method of weight average molecular weight of polyimide)

[0099] Prepare a tetrahydrofuran solution of polyimide at a concentration of 1 mg / mL, and use a size exclusion chromatography device (HLC-8320GPC manufactured by Tosoh Corporation) in an eluent: tetrahydrofuran (without stabilizer), column: TSKgel SuperHM-M (2 in ...

Embodiment X1

[0112] Add 461 g of solvent N,N-dimethylacetamide (DMAC) (containing 100 ppm of water; the following is used in all of Example X and Comparative Example X) in a glass 2L detachable flask equipped with a stirring device and stirring blades The same is true for DMAC) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) 64.047 g (0.2000 mol) of an aromatic diamine compound having a fluorine group were stirred, TFMB was dissolved in DMAC. Next, 4,4'-(1,1,1,3,3,3-hexafluoropropane-(1,1,1,3,3,3-hexafluoropropane- 2,2-diyl) bisphthalic anhydride (6FDA) 89.737g (0.2020 mol), in this state adjust the temperature to the temperature range of 20 ℃ ~ 40 ℃, while continuing to stir for 6 hours to carry out the polymerization reaction, to obtain Viscous polyamic acid solution. The tetracarboxylic dianhydride / aromatic diamine compound molar ratio used was 1.01, and the concentration of the polyamic acid solution was 25% by weight.

[0113] 410 g of DMAC was added to the obtained polya...

Embodiment X2

[0122] Using 16 g of the polyimide powder (a-1) obtained in Example X1, which is composed of polyimide with a reduced viscosity of 1.52 dL / g, is composed of polyimide with a reduced viscosity of 2.54 dL / g. The polyimide powder (b-1) 24g, the blending ratio of polyimide powder (a-1) and polyimide powder (b-1) is set as polyimide powder (b-1) by weight ratio Except imide powder (a-1) / polyimide powder (b-1)=40 / 60, it carried out similarly to Example X1.

[0123] The reduced viscosity measured about the obtained polyimide powder was 2.13 dL / g, and the average particle diameter was 0.06 mm. In addition, a polyimide film with a thickness of 50 μm obtained from the polyimide powder had a total light transmittance of 90%, a yellowness of 1.3, and extremely excellent transparency. In addition, the tensile strength of the polyimide film was 165 MPa. The elongation was excellent at 72%.

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Abstract

A polyimide powder which is composed of a blend of a polyimide powder A and a polyimide powder B and is soluble in an organic solvent, and which is characterized in that: the polyimide powder A and the polyimide powder B are composed of polyimides which have a structural unit that is derived from at least one aromatic diamine compound and a structural unit that is derived from at least one tetracarboxylic acid dianhydride; the polyimide powder A is composed of a polyimide which has (a-1) a reduced viscosity of 1.2 dL / g or more but less than 2.1 dL / g or (a-2) a weight average molecular weight of 100,000 g / mol or more but less than 250,000 g / mol; the polyimide powder B is composed of a polyimide which has (b-1) a reduced viscosity of from 2.1 dL / g to 3.0 dL / g (inclusive) or (b-2) a weight average molecular weight of from 250,000 g / mol to 500,000 g / mol (inclusive); the weight ratio of the polyimide powder A to the polyimide powder B is within the range of from 10 / 90 to 90 / 10; and a blendof the polyimide powder A and the polyimide powder B has a reduced viscosity within the range of from 1.7 dL / g to 2.5 dL / g, or a blend of the polyimide powder A and the polyimide powder B has a weightaverage molecular weight within the range of from 160,000 g / mol to 350,000 g / mol. This polyimide powder is soluble in an organic solvent, while having excellent handling properties. A varnish which is obtained by dissolving this polyimide powder into an organic solvent at a predetermined concentration forms a polyimide film that exhibits excellent heat resistance, transparency and mechanical characteristics.

Description

technical field [0001] The present invention relates to a polyimide powder, a polyimide varnish obtained by using the polyimide powder, and a polyimide film, and in particular to a polyimide film suitable for use in display applications or electronic materials, and extremely Polyimide powder and polyimide varnish for polyimide film with excellent heat resistance and transparency. Background technique [0002] Polyimide resins, as polymers excellent in heat resistance, are used in a wide range of fields requiring heat resistance and high reliability, such as aerospace, electrical insulation, and electronics. In addition, transparent polyimides having both heat resistance and transparency have been proposed in recent years. For example, Patent Document 1 proposes a soluble polyimide synthesized from a specific monomer containing fluorine atoms, which is suitable for optical waveguides and has excellent transparency. Polyimide. Patent Document 2 proposes an organic-solvent-so...

Claims

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Application Information

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IPC IPC(8): C08L79/08C08G73/10C08J5/18
CPCC08G73/10C08J5/18C08L79/08C08G73/1078C08G73/1039C08G73/1075C09D179/08C08J2379/08C08L2205/025
Inventor 田中圭三山田俊辅长岛丰清水诚吾
Owner KAWAMURA SANGYO KK
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