JP2011074286A - Method for producing polyimide composite, and polyimide composite - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyimide composite excellent in colorless transparency and dimensional stability. <P>SOLUTION: The method for producing the polyimide composite includes steps of: (1) at least reacting a tetracarboxylic acid dianhydride with a diamine compound in an organic solvent in which a phyllosilicate organized with an organic onium ion is dispersed, wherein at least either the tetracarboxylic acid dianhydride or the diamine compound is an aliphatic compound, so as to obtain a composite dispersion liquid containing a polyamic acid and the organized phyllosilicate; and (2) imidizing the composite dispersion liquid by heating. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a polyimide composite excellent in colorless transparency and dimensional stability, and a polyimide composite.

  In recent years, various flexible devices using a plastic film as a substrate instead of a glass substrate have been actively studied. For example, a flexible organic EL display, a film type solar cell, electronic paper, etc. are mentioned. High heat resistance, transparency, and dimensional stability are required in the device manufacturing process.

  Semi-aromatic (including polyamides with partially introduced aromatic structures in the molecular skeleton of aliphatic polyamides) or wholly aliphatic (including alicyclic structures) polyimides are excellent in colorless and transparent heat resistance. Since the property is also good, it has been actively studied as a base material for such a flexible device.

  For the purpose of improving the mechanical strength, lowering the coefficient of thermal expansion, improving the gas barrier property, etc., compounding of various organic resins and inorganic layered compounds has been actively studied, and there are many reports on polyimide.

  Patent Document 1 discloses a polyimide composite material composed of a layered clay mineral and polyimide that are organized with organic onium ions, and a method for producing the same.

  Patent Document 2 discloses a polyimide film containing a polyimide resin and a silane clay composite as a technique for solving the above-described problems.

  Patent Document 3 discloses a colorless and transparent polyimide composite film containing a polyimide obtained from an aliphatic tetracarboxylic acid derivative and an aliphatic or aromatic diamine, and an organized layered silicate treated with an ammonium ion having an alkylene oxide structure. Is disclosed.

JP-A-4-33955 JP 2000-7912 A JP 2006-37079 A

  However, semi-aromatic or wholly aliphatic polyimides are excellent in colorless transparency and heat resistance, but have a problem that the coefficient of thermal expansion is large. Moreover, it is thought that the aromatic polyimide described in Patent Document 1 is colored. Furthermore, the specific disclosure of organic onium ions is only alkylammonium ions, and the organic treatment with this compound may cause thermal decomposition during high-temperature treatment in the film production process. When it is generated and used as a film or the like, there is a problem that the toughness of the film is reduced and the film is easily broken.

  In Patent Document 2, a clay composite treated with a silane compound having excellent heat resistance is used to achieve a high elastic modulus of a polyimide film without impairing heat resistance and toughness. Has exchangeable ions, so that there is a problem that it cannot be sufficiently dispersed in the solution or the wall cannot be opened. Therefore, although the dimensional stability can be improved to some extent, there arises a problem that the effect is not sufficient.

  Although the polyimide disclosed in Patent Document 3 is colorless and transparent, the dispersion of the layered silicate is insufficient because the composite dispersion is prepared by polymerizing the soluble polyimide and then mixing with the layered silicate dispersion. There is a problem that there is.

  This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the polyimide-type composite_body | complex which is further excellent in dimensional stability, maintaining colorless transparency.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have found that at least one of a tetracarboxylic dianhydride and a diamine compound is an aliphatic compound, and a layered silicate that has been organized by an organic onium ion is dispersed. A step of obtaining at least one of the tetracarboxylic dianhydride and the diamine compound in an organic solvent to obtain a composite dispersion containing a polyamic acid and an organically modified layered silicate; and the composite dispersion. The method for producing a polyimide composite by performing imidization by molding and heating to obtain a polyimide composite, and found that the above-mentioned problems can be solved by the method for producing a polyimide composite, thereby completing the present invention. It was.

That is, the present invention is as follows.
[1]
(1) At least one of tetracarboxylic dianhydride and diamine compound is an aliphatic compound, and the tetracarboxylic dianhydride is added in an organic solvent in which a layered silicate organized by an organic onium ion is dispersed. Reacting at least a product with the diamine compound to obtain a composite dispersion containing a polyamic acid and an organically modified layered silicate;
(2) imidizing the composite dispersion by heating to obtain a polyimide composite;
The manufacturing method of the polyimide-type composite_body | complex containing.
[2]
The method for producing a polyimide-based composite according to [1], wherein the composite dispersion further contains a silane coupling agent.
[3]
The tetracarboxylic dianhydride is an aliphatic tetracarboxylic dianhydride;
The method for producing a polyimide-based composite according to [1] or [2], wherein the diamine compound is an aromatic diamine.
[4]
Any one of the above [1] to [3], wherein the complex dispersion contains at least one silane coupling agent selected from the group consisting of aminosilane, isocyanate silane, epoxy silane, and ureidosilane. A method for producing a polyimide-based composite.
[5]
Any one of the above [1] to [4], wherein 0.1 to 100 parts by mass of the organically modified layered silicate is added to 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound. A method for producing a polyimide-based composite.
[6]
The polyimide system according to any one of [1] to [5] above, wherein 8 to 100 parts by mass of the organically modified layered silicate is added to 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound. A method for producing a composite.
[7]
The polyimide system according to any one of [1] to [6] above, wherein 11 to 100 parts by mass of the organically modified layered silicate are added to 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound. A method for producing a composite.
[8]
In the step (2), the composite dispersion liquid is molded into a film and heated to imidize to obtain a polyimide composite film. The polyimide composite according to any one of the above [1] to [7] Manufacturing method.
[9]
A polyimide composite obtained by the production method according to any one of [1] to [8] above, wherein the total light transmittance is 85% or more and the haze value is 3% or less.

  According to the present invention, a polyimide composite having excellent colorless transparency, heat resistance and dimensional stability can be produced.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. The following are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

  In the method for producing a polyimide-based composite according to the present invention, (1) at least one of a tetracarboxylic dianhydride and a diamine compound is an aliphatic compound, and a layered silicate that is organized by organic onium ions is dispersed. A step of reacting at least the tetracarboxylic dianhydride and the diamine compound in an organic solvent to obtain a composite dispersion containing polyamic acid and an organically modified layered silicate; and (2) the composite And heating the body dispersion to imidize to obtain a polyimide composite.

  In the method for producing a polyimide composite according to the present invention, at least a tetracarboxylic dianhydride and a diamine compound are reacted in an organic solvent in which a layered silicate organized by organic onium ions is dispersed, A composite dispersion containing the polyamic acid and the organically modified layered silicate is obtained, imidized by molding it into a desired shape and heating. Therefore, the dispersibility of the layered silicate is very excellent compared to the method of mixing the polyamic acid solution synthesized in advance with the dispersion of the layered silicate. Moreover, since at least one of the tetracarboxylic dianhydride and the diamine compound is an aliphatic compound, the resulting polyimide composite is excellent in colorless transparency. The “polyimide composite” may be called a polyimide composite material, a polyimide composite material, a polyimide hybrid material, or the like.

(1) Step In the present invention, first, at least a tetracarboxylic dianhydride and a diamine compound are reacted in an organic solvent in which a layered silicate organized by an organic onium ion is dispersed, so that polyamic acid and organic A composite dispersion containing layered silicate is obtained.

  At least one of the tetracarboxylic dianhydride and the diamine compound is an aliphatic compound. As used herein, the aliphatic compound includes those having an alicyclic structure.

  Although it does not specifically limit as aliphatic tetracarboxylic dianhydride, For example, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,4,3 ', 4'-bicyclohexyltetracarboxylic dianhydride Bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, bicyclo [2,2,2 ] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2,2,2] -octane-2,3,5,6-tetracarboxylic dianhydride and the like Can be mentioned. Among these, from the viewpoint of heat resistance, transparency, and availability, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,4,3 ', 4'-bicyclohexyltetracarboxylic dianhydride Bicyclo [2,2,2] -octane-2,3,5,6-tetracarboxylic dianhydride is preferred. These aliphatic tetracarboxylic dianhydrides can be used singly or in combination of two or more.

The aliphatic diamine compound is not particularly limited, and examples thereof include 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 3 (4), 8 (9), − bis (aminomethyl) tricyclo [5,2,1,0 ^2,6] decane, 2,5 (6) - bis (aminomethyl) bicyclo [2,2,1] heptane, isophorone diamine, 1,3-bis (Aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, metaxylylenediamine, paraxylylenediamine, 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane 1,6-diaminohexane, 1,8-diaminooctane and the like. Among these, from the viewpoint of heat resistance and transparency, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, 3 (4), 8 (9),-bis (aminomethyl) tricyclo [5,2,1,0 ^2,6] decane, 2,5 (6) - bis (aminomethyl) bicyclo [2,2,1] heptane, isophorone diamine, 1,3-bis ( Aminomethyl) cyclohexane, 1,3-diaminocyclohexane and 1,4-diaminocyclohexane are preferred. These aliphatic diamine compounds can be used singly or in combination of two or more.

  In the present invention, when two or more tetracarboxylic dianhydrides or two or more diamine compounds are used, at least one of them may be an aliphatic compound. In the present invention, at least a combination of an aromatic acid anhydride and an aliphatic diamine compound, a combination of an aliphatic acid anhydride and an aromatic diamine compound, and a combination of an aliphatic acid anhydride and an aliphatic diamine compound are used as raw materials. When these are used together with aromatic tetracarboxylic dianhydride, aromatic diamine compound, etc., from the viewpoint of transparency, the chain structure of aromatic acid anhydride and aromatic diamine compound may not exist as much as possible in polyimide. It is preferable that it is not present at all. In particular, it is preferable that the tetracarboxylic dianhydride is an aliphatic compound and the diamine compound is an aromatic diamine compound.

  The aromatic tetracarboxylic dianhydride that can be used is not particularly limited. For example, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′ , 4,4′-benzophenone tetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 2,2′-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride and 3 , 3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride and the like. Among these, from the viewpoint of heat resistance, transparency, and availability, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 2,2 ′ -Bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride is preferred.

  Although it does not specifically limit as an aromatic diamine compound, For example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminobiphenyl, 4,4'-diamino-2,2 ' -Bis (trifluoromethyl) biphenyl, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylmethane, 4,4'-diamino Diphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis ( 3-Aminophenoxy) benzene, 4,4′-bis (4-aminophen) Noxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, And 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane.

  The layered silicate is not particularly limited, and examples thereof include smectite clay minerals such as montmorillonite, hectorite, saponite, beidellite, stevensite, and nontronite, swelling mica, vermiculite, and halloysite. It is preferable to contain at least one selected from the group consisting of montmorillonite, hectorite, saponite, swellable mica, and vermiculite because of its excellent swellability in a solvent. These layered silicates may be used alone or in combination of two or more.

Although it does not specifically limit as cation exchange capacity | capacitance (CEC) of a layered silicate, A preferable minimum is 50 milliequivalent / 100g, and an upper limit is 200 milliequivalent / 100g. When the amount is 50 milliequivalents / 100 g or more, the amount of the cationic substance intercalated between the crystal layers of the layered silicate by cation exchange is sufficient, so that the crystal layers can be sufficiently organicized. When it is 200 milliequivalents / 100 g or less, the bonding force between the crystal layers of the layered silicate does not become too strong, and an appropriate bonding force can be obtained, and the crystal flakes can be easily peeled off. The cation exchange capacity can be measured by NH ₄ AC (ammonium acetate solution) leaching method, centrifugal method, hydrogenation-barium exchange method, pH method.

  In the present invention, an organically modified layered silicate in which the layered silicate is treated with an organic onium ion is used. In the present invention, “organized layered silicate” refers to a layered silicate (organized layered silicate) treated with an organic onium ion. Examples of organic onium salts that generate such organic onium ions include quaternary ammonium salts, quaternary phosphonium salts, and imidazolium salts. Among these, a quaternary ammonium salt is preferable from the viewpoint that coloring can be effectively suppressed. These organic onium salts may be used alone or in combination of two or more.

  The quaternary ammonium salt is not particularly limited, and examples thereof include trimethylalkylammonium salt, triethylalkylammonium salt, tributylalkylammonium salt, trioctylalkylammonium salt, dimethyldialkylammonium salt, dibutyldialkylammonium salt, methylbenzyldialkylammonium salt. Dibenzyldialkylammonium salt, trialkylmethylammonium salt, trialkylethylammonium salt, trialkylbutylammonium salt, quaternary ammonium salt having an aromatic ring, quaternary ammonium salt derived from aromatic amines such as trimethylphenylammonium, polyethylene Dialkyl quaternary ammonium salt having two glycol chains, dialkyl quaternary ammonium having two polypropylene glycol chains Umushio, trialkyl quaternary ammonium salt having one polyethylene glycol chain, a trialkyl quaternary ammonium salt having one polypropylene glycol chain. Among these, from the viewpoint of dispersibility in organic solvents, lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl methyl ammonium salt, distearyl dimethyl ammonium salt, di-cured tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, N-polyoxyethylene-N-lauryl-N, N-dimethylammonium salt and the like are preferable. These quaternary ammonium salts may be used alone or in combination of two or more.

  The quaternary phosphonium salt is not particularly limited, and examples thereof include dodecyltriphenylphosphonium salt, methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, trioctylphosphonium salt, distearyldimethylphosphonium salt, and distearyl. And dibenzylphosphonium salts.

  The imidazolium salt is not particularly limited, and examples thereof include dimethylbutylimidazolium salt, dimethyloctylimidazolium salt, dimethyldecylimidazolium salt, dimethyldodecylimidazolium salt, and dimethylhexadecylimidazolium salt. Only one of these phosphonium salts and imidazolium salts may be used in combination with a quaternary ammonium salt, or two or more thereof may be used in combination.

  The organic solvent in the present invention is not particularly limited. For example, amides such as NN′-dimethylformamide, NN′-dimethylacetamide, and N-methyl-2-pyrrolidone; γ-butyrolactone, γ- Lactones such as valerolactone and δ-valerolactone; carbonates such as ethylene carbonate and propylene carbonate; glymes such as monoglyme, diglyme, triglyme and tetraglyme; and aprotic polar solvents such as dimethyl sulfoxide Can be mentioned.

  In the present invention, polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine compound in an organic solvent in which the organically modified layered silicate is dispersed. Thereby, the complex dispersion liquid containing a polyamic acid and organically modified layered silicate can be obtained. This polyamic acid is a polyimide precursor, and this composite dispersion can be used as an intermediate polymer of a polyimide composite.

  The method for obtaining a polyamic acid by reacting a tetracarboxylic dianhydride and a diamine compound is not particularly limited, and for example, a known method can be used. For example, a method in which tetracarboxylic dianhydride and a diamine compound are mixed in an equimolar amount and polymerized is exemplified. Although the compounding quantity of tetracarboxylic dianhydride and a diamine compound is not specifically limited, From a viewpoint of raising a polymerization degree enough and obtaining a tough film, a diamine compound is 0.95 with respect to 1 mol of tetracarboxylic dianhydrides. It is preferable that it is the range of -1.05 mol.

  The composite dispersion of polyamic acid and organically modified layered silicate preferably contains a silane coupling agent. By containing the silane coupling agent, condensation of the organically modified layered silicate in the composite dispersion can be prevented. As a result, the dispersibility in the composite dispersion can be further improved. More preferably, the composite dispersion contains at least one silane coupling agent selected from the group consisting of aminosilane, isocyanate silane, epoxy silane, and ureidosilane. These functional groups can react with the acid dianhydride or diamine of the polyimide raw material, and the hydrolyzable silyl group can react with the layered silicate. As a result, the polyamic acid or the polyimide obtained therefrom is immobilized by bonding with the layered silicate via the silane coupling agent.

  The silane coupling agent is not particularly limited, but more specifically, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane. N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N- ( Vinylibenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 4-aminophenyltrimethoxysilane, 3-aminophenyltrimethoxysilane, 2- (3-aminophenyl) ethyltrimethoxysilane, 3- Such as (4-aminophenoxy) propyltrimethoxysilane Isocyanatosilanes such as minosilane and 3-isocyanatopropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3 -Epoxy silanes such as glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane, and ureidosilanes such as γ-ureidopropyltriethoxysilane.

  When the composite dispersion contains the silane coupling agent described above, the polyimide resin is bonded to and immobilized on the layered silicate via the silane coupling agent. Thereby, reagglomeration of the layered silicate during high-temperature treatment can be reliably suppressed. As a result, the transparency is greatly improved, and the linear expansion coefficient, water absorption rate, and the like can be effectively reduced.

  The addition amount of the silane coupling agent is not particularly limited. In general, a suitable addition amount is calculated from the specific surface area when the layered silicate is dispersed in the polyimide resin and the monomolecular coating area of the silane coupling agent. it can. Furthermore, since the adsorption form of the silane coupling agent with respect to the layered silicate varies greatly depending on the concentration and pH of the solution, a more preferable addition amount can be calculated in consideration of this.

  In the present invention, the timing of adding the silane coupling agent is not particularly limited, after a method of adding in advance to the solvent in which the layered silicate is dispersed, or after obtaining a complex dispersion of the polyamic acid and the layered silicate, The method of adding to this etc. is mentioned. These are preferably selected as appropriate according to the silane coupling agent used and according to the preferred form of complexing with polyamic acid or polyimide. The method for dispersing the silane coupling agent in the solvent is not particularly limited, and a known method can be used. Examples thereof include a method of stirring in a solvent such as water, alcohol, or toluene.

  In the present invention, other inorganic fillers such as colloidal silica and colloidal alumina may be further added.

  Although the compounding quantity with respect to 100 mass parts of polyimide resin of the organically layered silicate is not specifically limited, As a minimum, 0.1 mass part is preferable, 8 mass parts is more preferable, 10 mass parts is more preferable, 11 Part by mass is even more preferable. As an upper limit, 100 mass parts is preferable and 50 mass parts is more preferable. By making the lower limit of the compounding amount of the organically modified layered silicate within the above range, an excellent improvement effect on the linear expansion coefficient can be obtained. By setting the upper limit of the amount of the layered organic silicate to be in the above range, excellent moldability can be obtained.

(2) Step In the present invention, the step of imidizing the composite dispersion obtained in step (1) to obtain a polyimide composite is performed. More specifically, the dehydration reaction of the polyamic acid contained in the composite dispersion can be advanced by molding and heating the composite dispersion. As a result, the formation of polyimide can be advanced.

  It does not specifically limit as a shaping | molding method, A well-known method can be used. For example, a method of accelerating the dehydration reaction by filling the complex dispersion liquid obtained in the step (1) into a molding frame having a desired shape and heating it. The shape to be molded is not particularly limited, and for example, a film (sometimes referred to as “sheet”. Alternatively, it may be a shape of various members. In this case, in the step (2), the composite dispersion is performed. It is preferable to obtain a polyimide-based composite film by forming the solution into a film and heating it, and the method of forming into a film is not particularly limited, for example, a composite dispersion on a support After coating and drying, a method of peeling this from the support and heating at high temperature to imidize; when the support is excellent in heat resistance such as metal, coating, drying, and heating imidization The method of peeling this after performing up to this on a support body etc. is mentioned.

  The method for imidizing the composite dispersion by heating is not particularly limited, and a known method can be employed. Examples of the heating method include hot air, infrared rays, far infrared rays, radiation, and an electric heater. Moreover, 200-400 degreeC is preferable and heating temperature has more preferable 250-350 degreeC.

  When setting it as a polyimide-type composite film, it is preferable to further include the process of extending | stretching the obtained film. By stretching the film, a composite film having a lower coefficient of thermal expansion and higher transparency can be obtained. Moreover, since the organically modified layered silicate such as clay can be oriented in the in-plane direction of the polyimide composite film, a high gas barrier property can be imparted to the polyimide composite film.

  The stretching method is not particularly limited, and for example, the solvent in the composite dispersion may be left to stretch at a low temperature, or may be stretched at a high temperature above the glass transition point. Further, uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, zone stretching, and the like may be used, but simultaneous or sequential biaxial stretching is preferable. When performing at high temperature, it is preferable to carry out in inert gas atmosphere, such as nitrogen. The stretching ratio is preferably 1.1 to 10 times.

  The polyimide composite according to the present invention has excellent transparency because the layered silicate is highly dispersed and the polyimide can be fixed to the layered silicate through a silane coupling agent. It has excellent heat resistance and a low coefficient of thermal expansion.

  As a preferable aspect of the polyimide composite obtained by the production method according to the present invention, a polyimide composite having a total light transmittance of 85% or more and a haze value of 3% or less can be obtained. The polyimide composite according to the present invention can be suitably used as a substrate for various flexible devices such as a flexible organic EL display, a flexible printed circuit board, a film type solar cell, and electronic paper. Moreover, it can also be set as laminates, such as a flexible copper clad laminated board (CCL), as materials, such as a flexible printed circuit board.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

  The physical properties were evaluated by the following methods.

  The total light transmittance was measured at three points using “TC-H3DPK” manufactured by Tokyo Denshoku to obtain an average value.

  The haze value was measured at three points using “TC-H3DPK” manufactured by Tokyo Denshoku, and the average value was obtained.

  The thermal expansion coefficient was measured using “TMA / SS6100” manufactured by SII Nanotechnology under a nitrogen atmosphere at a load of 100 mN and a heating rate of 5 ° C./min, and an average value from 100 ° C. to 200 ° C. was obtained.

  The glass transition temperature (Tg) was read from the inflection point of the thermal expansion coefficient curve.

Example 1
0.132 g of synthetic smectite treated with trioctylmethylammonium salt (Corp Chemical, “STN”) was added to 6 mL of dehydrated N, N-dimethylacetamide (Wako Pure Chemical). The mixture was vigorously stirred and dispersed uniformly. To this, 0.822 g of 4,4′-bis (4-aminophenoxy) biphenyl (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved uniformly, and then 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride. (Iwatani Gas Co., Ltd., “PMDA-HS”) 0.500 g was added and stirred at room temperature for several hours to obtain a viscous single yellow transparent dispersion.

  This dispersion was applied onto glass that had been peeled off using an applicator and dried at 60 ° C. for 30 minutes to obtain a composite film before imidization. The obtained composite film before imidization was peeled off from the glass, and a part of the film was sampled to evaluate its transparency. As a result, it was confirmed that the total light transmittance was 90.4% and the haze was 0.3%, and the transparency was excellent. This composite film before imidization was fixed to a metal frame and imidized by heat treatment at 300 ° C. for 1 hour under a nitrogen atmosphere to obtain an imidized composite film.

  The imidized composite film obtained was colorless and transparent and did not crack even when bent at 180 degrees. It was confirmed that the film had high transparency with a total light transmittance of 89.5% and a haze of 0.8%. The coefficient of thermal expansion was 51.9 ppm / ° C., confirming excellent dimensional stability. The glass transition temperature obtained from the TMA curve was 289 ° C., and it was confirmed that the glass was excellent in heat resistance.

(Reference Example 1)
A composite film before imidization was obtained in the same manner as in Example 1 except that the synthetic smectite treated with trioctylmethylammonium salt in Example 1 was changed to 0.330 g. When the transparency of this composite film before imidation was evaluated, it was excellent in transparency with a total light transmittance of 90.2% and a haze of 0.4%. About this composite film before imidation, the process similar to Example 1 was performed and the imidized composite film was obtained. The obtained composite film secured transparency although the haze value was slightly increased. The evaluation results are shown in Table 1.

(Reference Example 2)
A composite film before imidization was obtained in the same manner as in Example 1 except that the synthetic smectite treated with trioctylmethylammonium salt in Example 1 was changed to 0.660 g. When the transparency of the composite film before imidization was evaluated, the total light transmittance was 90.4% and the haze was 0.5%, which was very excellent in transparency. About this composite film before imidation, the process similar to Example 1 was performed and the imidized composite film was obtained. Although the obtained composite film had an increased haze value, the transparency was ensured. The evaluation results are shown in Table 1.

(Example 2)
Add 0.330 g of synthetic smectite (manufactured by Corp Chemical, “STN”) treated with trioctylmethylammonium salt to 6 mL of dehydrated N, N-dimethylacetamide (manufactured by Wako Pure Chemical Industries). The mixture was vigorously stirred and dispersed uniformly. To this, 0.822 g of 4,4′-bis (4-aminophenoxy) biphenyl (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved uniformly, and then 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride. (Iwatani Gas Co., Ltd., “PMDA-HS”) 0.500 g was added and stirred at room temperature for several hours to obtain a viscous single yellow transparent dispersion. Furthermore, 33 mg of 3-isocyanatopropyltriethoxysilane (manufactured by Tokyo Chemical Industry) was added and mixed uniformly.

  This dispersion was applied onto glass that had been peeled off using an applicator and dried at 60 ° C. for 30 minutes to obtain a composite film before imidization. The obtained composite film before imidization was peeled off from the glass, a part of the film was collected, and the transparency was evaluated. As a result, it was confirmed that the total light transmittance was 90.4% and the haze was 0.3%, and the transparency was excellent. This composite film before imidization was fixed to a metal frame and imidized by heat treatment at 300 ° C. for 1 hour under a nitrogen atmosphere to obtain an imidized composite film.

  The imidized composite film obtained was colorless and transparent and did not crack even when bent at 180 degrees. It was confirmed that the film had high transparency with a total light transmittance of 89.6% and a haze of 0.7%. The coefficient of thermal expansion was 39 ppm / ° C., confirming excellent dimensional stability. The glass transition temperature determined from the TMA curve was 281 ° C., and it was confirmed that the glass was excellent in heat resistance.

(Example 3)
In Example 2, the same procedure as in Example 1 was performed except that the synthetic smectite treated with trioctylmethylammonium salt was changed to 0.660 g, and 3-isocyanatopropyltriethoxysilane was changed to 53 mg. A composite film before imidization and an imidized composite film were obtained. The evaluation results are shown in Table 1.

(Comparative Example 1)
In Example 1, a film before imidization was obtained in the same manner as in Example 1 except that the organically treated synthetic smectite was not used. When the transparency of the film before imidization was evaluated, it was excellent in transparency with a total light transmittance of 90.3% and a haze of 0.1%. About this film before imidation, the process similar to Example 1 was performed and the imidized film was obtained. The obtained imidized film was highly transparent but had a high coefficient of thermal linear expansion. Each compounding amount (unit: parts by mass) of the organically modified layered silicate and the silane coupling agent with respect to a total of 100 parts by mass of the tetracarboxylic acid anhydride and the diamine compound, which are raw materials for the polyimide film, and the obtained polyimide composite film The evaluation results are shown in Table 1.

  As shown in Table 1, it was confirmed that all of the imidized composite films obtained in each Example were excellent in transparency and dimensional stability.

  According to the method for producing a polyimide-based composite according to the present invention, a polyimide-based composite having excellent transparency and dimensional stability can be obtained. This polyimide-based composite is a flexible organic EL display, a flexible printed board. It can be suitably used for a wide range of applications including substrates of various flexible devices such as film type solar cells and electronic paper.

Claims (9)

(1) At least one of tetracarboxylic dianhydride and diamine compound is an aliphatic compound, and the tetracarboxylic dianhydride is added in an organic solvent in which a layered silicate organized by an organic onium ion is dispersed. Reacting at least a product with the diamine compound to obtain a composite dispersion containing a polyamic acid and an organically modified layered silicate;
(2) imidizing the composite dispersion by heating to obtain a polyimide composite;
The manufacturing method of the polyimide-type composite_body | complex containing.   The method for producing a polyimide-based composite according to claim 1, wherein the composite dispersion further contains a silane coupling agent. The tetracarboxylic dianhydride is an aliphatic tetracarboxylic dianhydride;
The method for producing a polyimide-based composite according to claim 1 or 2, wherein the diamine compound is an aromatic diamine.   The said complex dispersion liquid contains at least 1 sort (s) of silane coupling agent selected from the group which consists of aminosilane, an isocyanate silane, an epoxy silane, and a ureido silane. A method for producing a polyimide-based composite.   5. The organically modified layered silicate is added in an amount of 0.1 to 100 parts by mass with respect to a total of 100 parts by mass of the tetracarboxylic dianhydride and the diamine compound. A method for producing a polyimide-based composite.   The polyimide system according to any one of claims 1 to 5, wherein 8 to 100 parts by mass of the organic layered silicate is added to 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound. A method for producing a composite.   The polyimide system according to any one of claims 1 to 6, wherein 11 to 100 parts by mass of the organically modified layered silicate are added to 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound. A method for producing a composite.   The polyimide composite according to any one of claims 1 to 7, wherein in the step (2), the composite dispersion is formed into a film and imidized by heating to obtain a polyimide composite film. Manufacturing method.   The polyimide-type composite body obtained by the manufacturing method as described in any one of Claims 1-8 whose total light transmittance is 85% or more and whose haze value is 3% or less.