CN102382303A

CN102382303A - Colorless and transparent polyimide resin material and preparation method thereof

Info

Publication number: CN102382303A
Application number: CN2011102338625A
Authority: CN
Inventors: 魏海兵; 陈国飞; 方省众; 侯亦嘉; 郭俊超; 王静刚
Original assignee: Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: According To Wuhan Ahmed New Materials Technology Co Ltd
Priority date: 2011-08-16
Filing date: 2011-08-16
Publication date: 2012-03-21
Anticipated expiration: 2031-08-16
Also published as: CN102382303B

Abstract

The invention discloses a colorless and transparent polyimide resin material. 1,2,3,4-cyclohexanetetracarboxylic dianhydride is chosen as dianhydride monomer or comonomer to carry out polycondensation reaction with primary diamine, so that the polyimide resin material is prepared. Because the 1,2,3,4-cyclohexanetetracarboxylic dianhydride comonomer has a distorted molecular structure, a large free volume exists between polymer molecular chains, and thereby the formation of charge transfer complex (CTC) in and between polyimide molecules is inhibited; and meanwhile, because of the introduction of a lipid structure, the electron-stimulated transition mode in the polyimide molecular chains is changed, the absorption of the aromatic polyimide in the visible light region is remarkably weakened, and thereby the transparency of the polymer is greatly increased. The ultraviolet light transmission cutoff wavelength of a produced polyimide film is 280nm to 380nm, the light transmissivity at 450nm is 86 to 94 percent, moreover, the glass-transition temperature is 250 DEG C to 400 DEG C, and the polyimide resin material has a good application prospect in the fields of flexible substrate materials for solar cells, flexible transparent conducting film substrate materials, liquid crystal display materials and the like.

Description

Colorless and transparent polyimide resin material and preparation method thereof

Technical Field

The invention relates to the technical field of polyimide materials, in particular to a colorless and transparent polyimide resin material and a preparation method thereof.

Background

Polyimide is a polymer with excellent comprehensive performance, has the characteristics of excellent heat resistance, low temperature resistance, solvent resistance, flame retardance and the like, and simultaneously has excellent dielectric property and mechanical property, so the polyimide is widely applied to the fields of electronics, microelectronics, aerospace, laser, photoelectricity and the like.

The high optical transparency can expand the application of the polyimide in the aspect of photoelectric materials, such as flexible substrates for solar cells, optical waveguide materials for communication connection, orientation films for liquid crystal displays, optical half-wave plates for planar lightwave circuits and the like. However, the conventional polyimide film generally has a tan color or brown color and a transmittance of less than 40% to 500nm light, which severely limits its application in the field of optoelectronics, mainly due to intramolecular and intermolecular Charge Transfer Complexes (CTCs) generated by electron withdrawing of carbonyl groups and electron donating of diamine residues alternately existing in a main chain of the polymer. Thus, to obtain a polyimide film that is light colored or even colorless, the formation of CTCs is reduced or eliminated.

Since the 80 s of the last century, methods for reducing the color of polyimide mainly include: (1) a fluorine-containing substituent is introduced into a polyimide molecular structure, and because fluorine atoms have great electronegativity, the conjugation of electron cloud can be cut off, and the formation of CTC is inhibited; (2) adopting a large side group or an asymmetric structural unit to block the conjugation of the electron cloud and inhibit the formation of CTC; (3) the polyimide with the aliphatic unit is obtained by using the dianhydride or diamine monomer with the aliphatic structure, so that the content of the aromatic structural unit in a polyimide molecular chain is reduced, the excited mode of electrons in the polyimide molecular chain is changed, and the formation of CTC is fundamentally inhibited.

At present, the method (1) is generally adopted to obtain light-colored polyimide films, and 2, 2-bis (3, 4-dicarboxylic acid) hexafluoropropane dianhydride is commonly used as a dianhydride monomer to obtain a series of light-colored and even colorless polyimide films which can meet different requirements. However, since 2, 2-bis (3, 4-dicarboxylic acid) hexafluoropropane dianhydride is extremely expensive, large-scale application of such polyimide films is limited. Meanwhile, in the method (2), the synthesis of the monomer with a large side group or an asymmetric structure is difficult, so that the method cannot be applied on a large scale. Thus, method (3) has received attention from numerous researchers, for example, as described in documents (Liu j.g., nakamuray.et al, chem.mater., 2008, 20, 273; US patent application publication US 6245881; ③ the published specification of the Chinese patent application with the publication number of CN 101084254A; documents such as chinese patent application publication No. CN101831074A report that polyimide synthesized from an alicyclic dianhydride monomer has high transparency and a low cut-off wavelength, and has high thermal stability and excellent solubility, and thus has attracted much attention.

Disclosure of Invention

The technical purpose of the present invention is to provide a new colorless and transparent polyimide resin material, which has the advantages of high transparency, high heat resistance, excellent solubility, low water absorption rate, etc., and has a good application prospect in the related fields of flexible substrate materials of solar cells, flexible transparent conductive film substrate materials, liquid crystal display materials, etc., in view of the above prior art.

The technical scheme adopted by the invention for realizing the technical purpose is as follows: a colorless transparent polyimide resin material having the following structural formula:

wherein n is₁And n₂Are integers greater than or equal to 1, A1 and A2 are residues of primary diamines, and A1 and A2 are independent of each other and are independent of each other. The residue of 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride represented by the above structural formula may be the following two isomeric units:

cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

Trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

Either one or a mixture of both.

Preferably, n in the above structural formula₁Value and n₂The value is an integer between 10 and 10000.

Preferably, the A1 and A2 are selected from one or more of the following groups:

the invention also provides another colorless and transparent polyimide resin material, which has the following structural formula:

wherein n is₁And n₂Are all integers greater than or equal to 1, B denotes the residue of a tetracarboxylic dianhydride other than the 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue, A1 and A2 are both residues of primary diamines, and A1 and A2 are independent of each other and are independent of each other. The residue of 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride represented by the above structural formula may be the following two isomeric units:

cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

Trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

Either one or a mixture of both.

Preferably, A1 and A2 are selected from one or more of the following groups:

preferably, B in the above formula is selected from

Any one or more of them.

The two polyimide resin materials provided by the invention are colorless and transparent, the glass transition temperature is 250-400 ℃, the ultraviolet absorption cut-off wavelength is 280-380 nm, and the light transmittance at 450nm is 86-94%.

The two colorless and transparent polyimide resin materials provided by the invention are synthesized by adopting polycondensation reaction.

Has the structural formula:

the preparation method of the colorless and transparent polyimide resin material comprises the following steps: the polyimide is prepared by the polycondensation reaction of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and a binary primary amine monomer; or the compound is obtained by the polycondensation reaction of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and two or more than two primary diamine monomers.

Has the structural formula:

the preparation method of the colorless and transparent polyimide resin material comprises the following steps: the mixture of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by B is obtained by polycondensation reaction with a primary diamine monomer; or the mixture of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by B is obtained by polycondensation reaction with two or more than two primary diamine monomers.

In the field of polymers, the content of each structural unit in the polymer can be generally controlled by the feed ratio of raw materials, and the content of each structural unit in the colorless and transparent polyimide resin material can also be controlled by the feed ratio of the raw materials.

The polycondensation reaction can adopt a one-step synthesis method and a two-step synthesis method.

The one-step synthesis method is that in an environment filled with inert gas (such as nitrogen, argon and the like), the tetracid dianhydride and the primary diamine monomer are fed into a phenolic solvent (such as m-cresol, p-chlorophenol and the like) according to an equivalent ratio, or a mixed solvent of a polar aprotic solvent (such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, gamma-butyrolactone and the like) and a benzene solvent (such as xylene, o-dichlorobenzene and the like) is added, the temperature is raised to a certain temperature, and then the polyimide solution is directly obtained by removing water generated in the reaction.

The two-step synthesis method comprises two steps, firstly, in an inert gas (such as nitrogen, argon and the like) filled environment, adding the tetracid dianhydride and the binary primary amine according to the equivalent ratio into a polar aprotic solvent (such as N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, gamma-butyrolactone and the like), reacting at a certain temperature to generate a polyamic acid precursor, and then carrying out imidization reaction by a high-temperature thermal imidization method or a catalyst chemical imidization method to convert the polyamic acid precursor into polyimide.

Taking the synthesis of polyimide resin material by polycondensation reaction of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 2, 2-bis (4-aminophenyl) hexafluoropropane as an example, the polymerization routes of the one-step synthesis method and the two-step synthesis method are shown in fig. 1 and fig. 2, respectively.

In both of the above-mentioned production methods, the primary dibasic amine may be selected from 4, 4 ' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4 ' -diaminodicyclohexylmethane, 1, 3-phenylenediamine, 3 ' -diaminodiphenylmethane, 4 ' -diaminodiphenylmethane, 3 ' -diaminodiphenyl ether, 4 ' -diaminodiphenyl ether, 3 ' -diaminodiphenyl sulfone, 4 ' -diaminodiphenyl sulfone, 3 ' -diaminobenzophenone, 4 ' -diaminobenzophenone, 2 ' -bis (trifluoromethyl) diaminobiphenyl, 2 ' -bis (trifluoromethyl) -4, 4 ' -diaminodiphenyl ether, 2 ' -bis (trifluoromethyl) -4, 4 '-diaminodiphenyl sulfide, 2-bis (4-aminophenyl) hexafluoropropane, 2-bis (3-aminophenyl) hexafluoropropane, 1, 3-bis (3-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4' -bis (3-aminophenoxy) diphenylsulfone, 2-bis [4- (3-aminophenoxy) phenyl ] hexafluoropropane, 1, 3-bis (4-amino-2-trifluoromethylphenoxy) benzene, 1, 3-bis (5-amino-3-trifluoromethylphenoxy) benzene, 2, 6-bis (2-trifluoromethyl-4-aminophenoxy) trifluorotoluene, 2, 6-bis (3-trifluoromethyl-5-aminophenoxy) trifluorotoluene, 4, 4 '-bis (2-trifluoromethyl-4-aminophenoxy) diphenyl sulfone, 4' -bis (3-trifluoromethyl-5-aminophenoxy) diphenyl sulfone, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] propane, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] propane, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] hexafluoropropane and 2, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] hexafluoropropane.

In the above two preparation methods, the other tetracarboxylic dianhydride denoted by B may be selected from 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride, 1, 2, 3, 4-cyclopentanetetracarboxylic dianhydride, 1, 2, 4, 5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2, 3, 5, 6-tetracarboxylic dianhydride, bicyclo [2.2.2] octane-2, 3, 5, 6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2, 3, 5, 6-tetracarboxylic dianhydride, 1, 2, 3, 4-biphenyltetracarboxylic dianhydride, 1, 2, 4, 5-benzenetetracarboxylic dianhydride, 2 ', 3, 3' -biphenyltetracarboxylic dianhydride, 2, 3, 3 ', 4' -biphenyltetracarboxylic anhydride, 2 ', 4, 4' -biphenyltetracarboxylic anhydride, 2, 2 ', 3, 3 ' -diphenylether tetracarboxylic anhydride, 2, 3, 3 ', 4 ' -diphenylether tetracarboxylic anhydride, 3, 3 ', 4, 4 ' -diphenylether tetracarboxylic anhydride, 2 ', 3, 3 ' -diphenylsulfide tetracarboxylic anhydride, 2, 3, 3 ', 4 ' -diphenylsulfide tetracarboxylic anhydride, 3, 3 ', 4, 4 ' -diphenylsulfide tetracarboxylic anhydride, 1, 4-bis (3, 4-dicarboxyphenoxy) benzene dianhydride, 1, 3-bis (3, 4-dicarboxyphenoxy) benzene dianhydride, 2-bis [4- (3, 4-dicarboxyphenoxy) phenyl ] hexafluoropropane dianhydride, 2-bis [4- (3, 4-dicarboxyphenoxy) phenyl ] propane dianhydride, 4, 4 ' -bis (3, 4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4, 4 '-bis (3, 4-dicarboxyphenoxy) diphenyl sulfide dianhydride and/or 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl ether dianhydride.

Compared with the prior art, the colorless and transparent polyimide resin material provided by the invention adopts asymmetric aliphatic dianhydride, namely 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride as a dianhydride monomer or comonomer, and reacts with aromatic diamine to obtain polyimide. Because the 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride monomer is an aliphatic cyclic dianhydride, the obtained polymer is subjected to light excitation, and the transition from pi → pi to transition of the traditional aromatic polyimide is changed into n → pi to transition, and higher energy is needed, so that the lower cut-off wavelength and better light transmittance are shown; meanwhile, the 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride monomer has a distorted molecular structure, so that the obtained polymer has a larger free volume, and the formation of a Charge Transfer Complex (CTC) in polyimide molecules and among molecules is inhibited. The absorption of the aromatic polyimide in a visible light region is obviously weakened by the combined action of the two, so that the transparency of the polyimide resin material is greatly improved, and the polyimide resin material with the ultraviolet light transmission cutoff wavelength of 280 nm-380 nm, the light transmittance at 450nm of 86% -94% and the glass transition temperature of 250 ℃ -400 ℃ is obtained. In addition, due to the introduction of the fat ring, the obtained polyimide resin material has good solubility and low water absorption rate. Therefore, the polyimide resin material has the advantages of high transparency, high glass transition temperature, good heat resistance, good solubility, low water absorption and the like, and has good application prospects in the related fields of flexible substrate materials of solar cells, flexible transparent conductive film substrate materials, liquid crystal display materials and the like. Finally, the synthesis of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride, which is one of the main raw materials adopted by the invention, is simple, and the cost of the raw materials is lower.

As a novel polyimide resin material, various embodiments include, for example, the polyimide resin material of the present invention can be formed into a film, a plastic, a fiber, or the like, and applied to various related fields.

Drawings

FIG. 1 is an exemplary polymerization scheme for preparing a polyimide resin material of the present invention using a one-step synthesis;

FIG. 2 is an exemplary polymerization route for preparing the polyimide resin material of the present invention using a two-step synthesis method;

FIG. 3 is a graph showing the transmittance of a polyimide film obtained by using the polyimide resin materials of example 1 and comparative example 1 to light having a wavelength of 200nm to 800 nm.

Detailed Description

The invention is described in further detail below with reference to the figures and examples.

Example 1:

in this embodiment, the colorless and transparent polyimide resin material has the following structural formula:

the preparation method comprises the following steps: 16.0 g (0.05 mol) of 2, 2' -bis (trifluoromethyl) diaminobiphenyl and 200 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After the 2, 2' -bis (trifluoromethyl) diaminobiphenyl was completely dissolved, 5.6 g (0.025 mole) of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 5.6 g (0.025 mole) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride were added and stirring was continued until both were completely dissolved. Then the temperature is increased to 180 ℃ for reaction for 5 h. And in the reaction process, water generated by the reaction is removed from the reaction system by a water removal device to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain the polyimide powder resin. Wherein the glass transition temperature of the polymer powder is 358 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N, N-dimethylformamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box with nitrogen protection, and heating according to the following procedures: firstly, keeping the temperature at 80 ℃ for 4 h; then heating to 150 ℃, and preserving heat for 1 h; then heating to 200 ℃, and preserving heat for 1 h; finally, the temperature is raised to 240 ℃, and the temperature is kept for 0.5 h. The temperature-raising program can be abbreviated as: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; 240 ℃ for 0.5 h. And (3) taking out the glass plate after the temperature is reduced to the room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at the temperature of 120 ℃ for drying for 2 hours to obtain a colorless and transparent film made of the polyimide resin material, wherein the thickness of the film is 15 microns.

The film prepared by the method is tested by an ultraviolet visible spectrometer to have a transmission curve, the ultraviolet absorption cut-off wavelength of the film is 288nm, and the light transmittance at 450nm is 91.4%.

Comparative example 1:

this example is a comparative example to example 1.

In this embodiment, the polyimide resin material has the following structural formula:

the preparation method comprises the following steps: 16.0 g (0.05 mol) of 2, 2' -bis (trifluoromethyl) diaminobiphenyl and 280 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After the 2, 2 ' -bis (trifluoromethyl) diaminobiphenyl was completely dissolved, 16.3 g (0.05 mol) of 2, 3, 3 ', 4 ' -diphenyl sulfide tetracarboxylic dianhydride was added and stirring was continued until both were completely dissolved. Then the temperature is increased to 180 ℃ for reaction for 5 h. And in the reaction process, water generated by the reaction is removed from the reaction system by a water removal device to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain the polyimide powder resin. Wherein the glass transition temperature of the polymer powder is 285 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N, N-dimethylacetamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box with nitrogen protection, and heating according to the following procedures: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; 240 ℃ for 0.5 h. And (3) taking out the glass plate after the temperature is reduced to the room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at the temperature of 120 ℃ for drying for 2 hours to obtain the polyimide film with the thickness of 15 microns.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 408nm, and the light transmittance at 450nm is 81.5%.

FIG. 3 is a graph showing the transmittance of the polyimide resin films of example 1 and comparative example 1 to light having a wavelength of 200nm to 800 nm. As can be seen from fig. 1, the transmittance of the film at all wavelengths is greatly improved and the cutoff wavelength is greatly reduced in the polyimide resin material obtained by polymerizing 2, 2 '-bis (trifluoromethyl) diaminobiphenyl with 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride under the same film thickness, compared to the polyimide resin material synthesized by polymerizing 2, 2' -bis (trifluoromethyl) diaminobiphenyl with other tetracarboxylic dianhydrides, such as 2, 3, 3 ', 4' -diphenylsulfide tetracarboxylic dianhydride.

Example 2:

the preparation method comprises the following steps: 16.7 g (0.05 mol) of 2, 2-bis (4-aminophenyl) hexafluoropropane and 160 ml of N, N-dimethylformamide were charged into a reactor equipped with a stirrer at room temperature. After 2, 2' -bis (4-aminophenyl) hexafluoropropane was completely dissolved, 11.2 g (0.05 mole) of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride was added at room temperature. After the system is completely dissolved, the temperature is raised to 50 ℃, and the stirring is continued for 3h, so as to prepare viscous polyamic acid solution.

The polyamic acid solution was coated on a clean glass plate, which was placed in a nitrogen blanketed dry box and the temperature was raised according to the following procedure: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; at 250 ℃ for 1 h; 300 ℃ for 0.5 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 18 mu m. Wherein the glass transition temperature of the film is 328 ℃.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 292nm, and the light transmittance at 450nm is 90.2%.

Example 3:

the preparation method comprises the following steps: 16.7 g (0.05 mol) of 2, 2-bis (4-aminophenyl) hexafluoropropane and 100 ml of N-methylpyrrolidone were charged into a reactor equipped with a stirrer at room temperature. After 2, 2' -bis (4-aminophenyl) hexafluoropropane was completely dissolved, 11.2 g (0.05 mol) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 50 ml of o-dichlorobenzene were added at room temperature. Stirring was continued until both dissolved completely. Then the temperature is increased to 180 ℃ for reaction for 10 h. And in the reaction process, water generated by the reaction is removed from the reaction system by a water removal device to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the glass transition temperature of the polymer powder is 323 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N, N-dimethylformamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box with nitrogen protection, and heating according to the following procedures: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; 220 ℃ and 0.5 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 16 microns.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 294nm, and the light transmittance at 450nm is 90.3%.

Example 4:

the preparation method comprises the following steps: 16.8 g (0.05 mol) of 2, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether and 200 ml of m-cresol are introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After 2, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether was completely dissolved, 11.2 g (0.05 mol) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride was added and stirring was continued until both were completely dissolved. Then the temperature is increased to 180 ℃ for reaction for 5 h. And in the reaction process, water generated by the reaction is removed from the reaction system by a water removal device to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain the polyimide powder resin. Wherein the glass transition temperature of the polymer powder is 308 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 12% by using N, N-dimethylacetamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying oven at 80 ℃ for 10 hours, and then taking out and placing the glass plate in a vacuum oven to heat according to the following procedures: at 80 ℃ for 1 h; 1h at 100 ℃; at 140 ℃ for 1 h; 1h at 180 ℃; 230 ℃ for 1 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 18 mu m.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 297nm, and the light transmittance at 450nm is 90.0%.

Example 5:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the ratio of the amounts of substances of 2, 2 '-bis (trifluoromethyl) diaminobiphenyl and 4, 4' -bis (3-trifluoromethyl-5-aminophenoxy) diphenylsulfone in the reactant charge is 7/3:

the preparation method comprises the following steps: 11.2 g (0.035 mol) of 2, 2 '-bis (trifluoromethyl) diaminobiphenyl, 8.5 g (0.015 mol) of 4, 4' -bis (3-trifluoromethyl-5-aminophenoxy) diphenylsulfone and 230 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After the two diamines were completely dissolved, 11.2 g (0.05 mole) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride was added at room temperature and stirring was continued until the dianhydride was completely dissolved. Then the temperature is increased to 180 ℃ for reaction for 5 h. And (3) removing water generated in the reaction from the reaction system by using a water removal device during the reaction process to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the polymer powder has a glass transition temperature of 299 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 12% by using N, N-dimethylformamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box with nitrogen protection, and heating according to the following procedures: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; 220 ℃ and 0.5 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 14 mu m.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 295nm, and the light transmittance at 450nm is 90.2%.

Example 6:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the amount ratio of substances of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 2, 3, 3 ', 4' -diphenylether tetracarboxylic anhydride in the reactant charge is 9/1:

the preparation method comprises the following steps: 21.4 g (0.05 mol) of 1, 3-bis (4-amino-2-trifluoromethylphenoxy) benzene and 210 ml of N, N-dimethylformamide are introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After 1, 3-bis (4-amino-2-trifluoromethylphenoxy) benzene was completely dissolved, 1.6 g (0.005 mol) of 2, 3, 3 ', 4' -diphenylether tetracarboxylic anhydride and 10.1 g (0.045 mol) of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride were added, and stirring was continued until both were completely dissolved. After the system is completely dissolved, continuously stirring and reacting for 3h at normal temperature to prepare viscous polyamic acid solution.

The polyamic acid solution was coated on a clean glass plate, which was placed in a nitrogen blanketed dry box and the temperature was raised according to the following procedure: 4h at 80 ℃; at 150 ℃, for 1 h; at 200 ℃ for 1 h; 0.5h at 250 ℃; 290 ℃ and 0.5 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 18 mu m. Wherein the glass transition temperature of the film is 296 ℃.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 306nm, and the light transmittance at 450nm is 89.2%.

Example 7:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the amount ratio of substances of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 2, 3, 3 ', 4' -diphenylethertetracarboxylic dianhydride in the reactant charge is 1/1:

the preparation method comprises the following steps: 16.0 g (0.05 mol) of 2, 2' -bis (trifluoromethyl) diaminobiphenyl and 250 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After the 2, 2 ' -bis (trifluoromethyl) diaminobiphenyl was completely dissolved, 5.6 g (0.025 mole) of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 7.8 g (0.025 mole) of 2, 3, 3 ', 4 ' -diphenylether tetracarboxylic dianhydride were added, and stirring was continued until both were completely dissolved. Then the temperature is increased to 190 ℃ for reaction for 8 h. And removing water generated in the reaction from the reaction system by using a water removal device during the reaction process to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the glass transition temperature of the polymer powder is 322 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N-methylpyrrolidone, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box, keeping the temperature at 80 ℃ for 10 hours, taking out, and placing in a vacuum oven to heat according to the following procedures: at 80 ℃ for 1 h; 1h at 100 ℃; at 140 ℃ for 1 h; 1h at 180 ℃; 230 ℃ for 1 h. And (3) taking out the glass plate after the temperature is reduced to the room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at the temperature of 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 19 microns.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 353nm, and the light transmittance at 450nm is 87.1%.

Example 8:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the amount ratio of substances of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 2, 3, 3 ', 4' -diphenylethertetracarboxylic dianhydride in the reactant charge is 1/4:

the preparation method comprises the following steps: 16.0 g (0.05 mol) of 2, 2' -bis (trifluoromethyl) diaminobiphenyl and 250 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After the 2, 2 ' -bis (trifluoromethyl) diaminobiphenyl was completely dissolved, 2.2 g (0.01 mole) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 12.4 g (0.04 mole) of 2, 3, 3 ', 4 ' -diphenylether tetracarboxylic dianhydride were added, and stirring was continued until both were completely dissolved. Then the temperature is increased to 190 ℃ for reaction for 8 h. And removing water generated in the reaction from the reaction system by using a water removal device during the reaction process to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the glass transition temperature of the polymer powder is 312 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 13% by using N-methylpyrrolidone, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying box, keeping the temperature at 80 ℃ for 10 hours, taking out, and placing in a vacuum oven to heat according to the following procedures: at 80 ℃ for 1 h; 1h at 100 ℃; at 140 ℃ for 1 h; 1h at 180 ℃; 230 ℃ for 1 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 22 mu m.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 360nm, and the light transmittance at 450nm is 86.3%.

Example 9:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the ratio of the amounts of substances of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 3, 3 ', 4, 4' -biphenyltetracarboxylic dianhydride in the reactant charge is 9/1:

the preparation method comprises the following steps: 16.0 g (0.05 mol) of 2, 2' -bis (trifluoromethyl) diaminobiphenyl and 250 ml of m-cresol were introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After 2, 2 ' -bis (trifluoromethyl) diaminobiphenyl was completely dissolved, 10.1 g (0.045 mol) of cis-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 1.5 g (0.005 mol) of 3, 3 ', 4, 4 ' -biphenyltetracarboxylic dianhydride were added, and stirring was continued until both were completely dissolved. Then the temperature is increased to 190 ℃ for reaction for 8 h. And removing water generated in the reaction from the reaction system by using a water removal device during the reaction process to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the glass transition temperature of the polymer powder is 324 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N, N-dimethylacetamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying oven at 80 ℃ for 10 hours, and then taking out and placing the glass plate in a vacuum oven to heat according to the following procedures: at 80 ℃ for 1 h; 1h at 100 ℃; at 140 ℃ for 1 h; 1h at 180 ℃; 200 ℃ for 1 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 14 mu m.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 352nm, and the light transmittance at 450nm is 88.0%.

Example 10:

in this example, the colorless and transparent polyimide resin material has the following structural formula, wherein the ratio of the amounts of substances of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and 3, 3 ', 4, 4' -triphenyldiether tetracarboxylic dianhydride in the reactant charge is 1/1:

the preparation method comprises the following steps: 16.8 g (0.05 mol) of 2, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether and 120 ml of N-methylpyrrolidone are introduced at room temperature into a reactor equipped with a stirrer and protected with nitrogen. After 2, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether was completely dissolved, 5.6 g (0.025 mol) of trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride, 10.1 g (0.025 mol) of 1, 4-bis (3, 4-dicarboxyphenoxy) benzene dianhydride, and 50 ml of o-dichlorobenzene were added, and stirring was continued until both were completely dissolved. Then the temperature is increased to 180 ℃ for reaction for 10 h. And (3) removing water generated in the reaction from the reaction system by using a water removal device during the reaction process to obtain the polyimide solution. And dripping the reaction liquid into ethanol to obtain fibrous polyimide precipitate, and drying to obtain polyimide powder. Wherein the glass transition temperature of the polymer powder is 304 ℃.

Preparing the obtained polyimide powder into a solution with the weight percentage concentration of 10% by using N, N-dimethylacetamide, coating the solution on a clean glass plate by using a tape casting method, placing the glass plate in a drying oven at 80 ℃ for 10 hours, and then taking out and placing the glass plate in a vacuum oven to heat according to the following procedures: at 80 ℃ for 1 h; 1h at 100 ℃; at 140 ℃ for 1 h; 1h at 180 ℃; 200 ℃ for 1 h. And (3) taking out the glass plate after the temperature is reduced to room temperature, putting the glass plate into warm water for demoulding, and then putting the film into a drying oven at 120 ℃ for drying for 2 hours to obtain a colorless and transparent polyimide film with the thickness of 21 mu m.

The transmission curve of the film prepared by the method is tested by an ultraviolet visible spectrometer, the ultraviolet absorption cut-off wavelength of the film is 366nm, and the light transmittance at 450nm is 88.1%.

Claims

1. A colorless and transparent polyimide resin material, characterized in that: the polyimide resin material has the following chemical formula:

wherein,

is a number of 1 s, and the number of the main chain is,the residue of 2, 3, 4-cyclohexane tetracarboxylic dianhydride has the structure of cis-1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride residue

And trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

One of them, or a mixture of the two structures;

n₁and n₂Are integers greater than or equal to 1, A1 and A2 are residues of primary diamines, and A1 and A2 are independent of each other and are independent of each other.

2. The colorless and transparent polyimide resin material according to claim 1, wherein: a1 and A2 are one or more of the following groups:

3. the colorless and transparent polyimide resin material according to claim 1 or 2, characterized in that: n is₁Value and n₂The value is between 10 and 10000.

4. The colorless and transparent polyimide resin material according to claim 1 or 2, characterized in that: the glass transition temperature of the polyimide resin material is 250-400 ℃, the ultraviolet absorption cut-off wavelength is 280-380 nm, and the light transmittance at 450nm is 86-94%.

5. The method for producing a colorless and transparent polyimide resin material according to claim 1 or 2, wherein the polyimide resin material is obtained by polycondensation of 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and one type of primary diamine monomer, or 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride and two or more types of primary diamine monomers;

wherein, the 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride is any one of or a mixture of two dianhydride monomers of cis-1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and trans-1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride.

6. The method for producing a colorless transparent polyimide resin material according to claim 5, characterized in that: the primary diamine is selected from 4, 4 '-diaminodicyclohexylmethane, 3' -dimethyl-4, 4 '-diaminodicyclohexylmethane, 1, 3-phenylenediamine, 3' -diaminodiphenylmethane, 4 '-diaminodiphenylmethane, 3' -diaminodiphenyl ether, 4 '-diaminodiphenyl ether, 3' -diaminodiphenyl sulfone, 4 '-diaminodiphenyl sulfone, 3' -diaminodiphenyl ketone, 4 '-diaminodiphenyl ketone, 2' -bis (trifluoromethyl) diaminobiphenyl, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl sulfide, thioether, 2, 2-bis (4-aminophenyl) hexafluoropropane, 2-bis (3-aminophenyl) hexafluoropropane, 1, 3-bis (3-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4' -bis (3-aminophenoxy) diphenylsulfone, 2-bis [4- (3-aminophenoxy) phenyl ] hexafluoropropane, 1, 3-bis (4-amino-2-trifluoromethylphenoxy) benzene, 1, 3-bis (5-amino-3-trifluoromethylphenoxy) benzene, 2, 6-bis (2-trifluoromethyl-4-aminophenoxy) trifluorotoluene, 2, 6-bis (3-trifluoromethyl-5-aminophenoxy) trifluorotoluene, 2, 6-bis (3-aminophenyl) trifluorotoluene, 4, 4 '-bis (2-trifluoromethyl-4-aminophenoxy) diphenyl sulfone, 4' -bis (3-trifluoromethyl-5-aminophenoxy) diphenyl sulfone, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] propane, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] propane, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] hexafluoropropane and 2, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] hexafluoropropane.

7. A colorless and transparent polyimide resin material, characterized in that: the polyimide resin material has the following chemical formula:

wherein,

is the residue of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and has the structure of cis-1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride residue

And trans-1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride residue

One of them, or a mixture of the two structures;

n₁and n₂Are all integers greater than or equal to 1, B denotes the tetrasubstituted residue of a tetracarboxylic dianhydride other than 1, 2, 3, 4-cyclohexanetetracarboxylic dianhydride, A1 and A2 are primary diamine residues, and A1 and A2 are independent of and unrelated to each other.

8. The colorless and transparent polyimide resin material according to claim 7, wherein: a1 and A2 are one or more of the following groups:

9. the colorless and transparent polyimide resin material according to claim 7 or 8, characterized in that: the B is selected from any one or more of the following groups:

10. the colorless and transparent polyimide resin material according to claim 7 or 8, characterized in that: the n1 value and the n2 value are between 10 and 10000.

11. The colorless and transparent polyimide resin material according to claim 7 or 8, characterized in that: the glass transition temperature of the polyimide resin material is 250-400 ℃, the ultraviolet absorption cut-off wavelength is 280-380 nm, and the light transmittance at 450nm is 86-94%.

12. The method for producing a colorless and transparent polyimide resin material according to claim 7 or 8, characterized in that: the colorless transparent polyimide material is obtained by the polycondensation reaction of a mixture of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and other tetracarboxylic dianhydride indicated by B and a binary primary amine monomer; or the mixture of 1, 2, 3, 4-cyclohexane tetracarboxylic dianhydride and other tetracarboxylic dianhydride represented by B is obtained by polycondensation reaction with two or more than two primary diamine monomers;

13. The method for producing a colorless and transparent polyimide resin material according to claim 12, characterized in that: the primary diamine is selected from 4, 4 '-diaminodicyclohexylmethane, 3' -dimethyl-4, 4 '-diaminodicyclohexylmethane, 1, 3-phenylenediamine, 3' -diaminodiphenylmethane, 4 '-diaminodiphenylmethane, 3' -diaminodiphenyl ether, 4 '-diaminodiphenyl ether, 3' -diaminodiphenyl sulfone, 4 '-diaminodiphenyl sulfone, 3' -diaminodiphenyl ketone, 4 '-diaminodiphenyl ketone, 2' -bis (trifluoromethyl) diaminobiphenyl, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl ether, 2 '-bis (trifluoromethyl) -4, 4' -diaminodiphenyl sulfide, thioether, 2, 2-bis (4-aminophenyl) hexafluoropropane, 2-bis (3-aminophenyl) hexafluoropropane, 1, 3-bis (3-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4' -bis (3-aminophenoxy) diphenylsulfone, 2-bis [4- (3-aminophenoxy) phenyl ] hexafluoropropane, 1, 3-bis (4-amino-2-trifluoromethylphenoxy) benzene, 1, 3-bis (5-amino-3-trifluoromethylphenoxy) benzene, 2, 6-bis (2-trifluoromethyl-4-aminophenoxy) trifluorotoluene, 2, 6-bis (3-trifluoromethyl-5-aminophenoxy) trifluorotoluene, 2, 6-bis (3-aminophenyl) trifluorotoluene, 4, 4 '-bis (2-trifluoromethyl-4-aminophenoxy) diphenyl sulfone, 4' -bis (3-trifluoromethyl-5-aminophenoxy) diphenyl sulfone, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] propane, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] propane, 2-bis [4- (2-trifluoromethyl-4-aminophenoxy) phenyl ] hexafluoropropane and 2, 2-bis [4- (3-trifluoromethyl-5-aminophenoxy) phenyl ] hexafluoropropane.

14. The method for producing a colorless and transparent polyimide resin material according to claim 12, characterized in that: the other tetracarboxylic dianhydride represented by B is selected from 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride, 1, 2, 3, 4-cyclopentanetetracarboxylic dianhydride, 1, 2, 4, 5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2, 3, 5, 6-tetracarboxylic dianhydride, bicyclo [2.2.2] octane-2, 3, 5, 6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2, 3, 5, 6-tetracarboxylic dianhydride, 1, 2, 3, 4-biphenyltetracarboxylic dianhydride, 1, 2, 4, 5-benzenetetracarboxylic dianhydride, 2 ', 3, 3' -biphenyltetracarboxylic anhydride, 2, 3, 3 ', 4' -biphenyltetracarboxylic anhydride, 3, 3 ', 4, 4' -biphenyltetracarboxylic anhydride, 2 ', 3, 3' -diphenylether tetracarboxylic anhydride, 1, 2, 3 ', 3, 4' -biphenyltetracarboxylic anhydride, 2, 3, 3 ', 4' -diphenyl ether tetracarboxylic anhydride, 3, 3 ', 4, 4' -diphenyl ether tetracarboxylic anhydride, 2 ', 3, 3' -diphenyl sulfide tetracarboxylic anhydride, 2, 3, 3 ', 4' -diphenyl sulfide tetracarboxylic anhydride, 3, 3 ', 4, 4' -diphenyl sulfide tetracarboxylic anhydride, 1, 4-bis (3, 4-dicarboxyphenoxy) benzene dianhydride, 1, 3-bis (3, 4-dicarboxyphenoxy) benzene dianhydride, 2-bis [4- (3, 4-dicarboxyphenoxy) phenyl ] hexafluoropropane dianhydride, 2-bis [4- (3, 4-dicarboxyphenoxy) phenyl ] propane dianhydride, 4, 4 '-bis (3, 4-dicarboxyphenoxy) diphenyl sulfone dianhydride, 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl sulfide dianhydride and 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl ether dianhydride.