JP2005154508A - Polyimide composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyimide composition that comprises a block copolymer having regularity and has excellent storage stability at a normal temperature, to provide a method for producing the same, to obtain a soluble polyimide composition for liquid-crystal orientation film, which has a pretilt angle not lowering even by aging of a liquid-crystal cell and controls development of stripe domain and development of streak-like domain by rubbing flaws and to provide a method for producing the soluble polyimide composition. <P>SOLUTION: The block copolymer is obtained by reacting an alicyclic tetracarboxylic acid dianhydride with an aromatic diamine in the presence of a lactone-based catalyst in a heated polar solvent, further adding an aromatic tetracarboxylic acid dianhydride and an alicyclic diamine to react them, adding an aromatic tetracarboxylic acid dianhydride and a trifluoromethyl group-containing fluorine-based aromatic diamine to react them at a normal temperature and directly causing imidization reaction without passing through a polyamic acid of an intermediate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyimide having excellent storage stability at room temperature and a method for producing the same, and more particularly to a polyimide composition having a regular block copolymer and excellent in storage stability at room temperature and a method for producing the same. The present invention also provides a polyimide composition that can be used for a liquid crystal alignment film that does not decrease the pretilt angle even when the liquid crystal cell is aged and suppresses the generation of stripe domains and the occurrence of streak-like domains due to rubbing scratches, and its Provide a manufacturing method

  Polyimide resin is excellent in heat resistance, electrical insulation, and abrasion resistance, and has appropriate mechanical strength and elongation. For example, heat-resistant insulation coating materials for electronic and electrical parts such as films for flexible printed circuit boards , Widely used in aerospace materials or vehicle materials. Moreover, it arrange | positions between the transparent electrodes of a liquid crystal display, and is used as an alignment film which performs an alignment process.

  In general, when a polyimide resin is a homopolymer composed of one kind of acid component and one kind of diamine component, it is difficult to impart sufficient functions to the resin. Has been done.

  In general, a polyimide resin is generally prepared by mixing equimolar amounts of high-purity acid dianhydride and aromatic diamine, and performing a polycondensation reaction at a low temperature in a polar solvent. Next, a method is adopted in which a polyamic acid solution is cast and a dehydration ring closure reaction is performed by heating or chemical treatment by addition of acetic anhydride.

  In this polyimide production method, the polyamic acid solution produced as an intermediate is inferior in storage stability at room temperature and is extremely unstable with respect to heat, so that it easily forms water and imidizes when heated. It is known that the generated water acts on the polyamic acid to promote hydrolysis of the polyamic acid and cuts the molecular chain to become a low molecular weight polyamic acid.

  In recent years, in order to produce a high-performance, high-molecular weight polyimide, a method for producing a high-molecular weight polyamic acid at room temperature or a low temperature below it has been adopted. The high molecular weight polyamic acid is soluble in polar solvents such as N-methyl-2-pyrrolidone (hereinafter referred to as “NMP”), dimethylformamide (hereinafter referred to as “DMF”), but most high molecular weight polyimides are used. Insoluble in these solvents, a two-step synthesis method for producing a polyimide resin which is a random copolymer via a polyamic acid is employed. Since this polyamic acid type polyimide solution has poor storage stability at room temperature, it has difficulty in use. Random copolymers are also used in alternating copolymers and block copolymers because the properties of the produced copolymer exhibit an average property that is inferior to that of each component. It is said that the properties are inferior both physically and chemically.

  Therefore, a method using a block copolymerization method for improving the characteristics of the polyimide resin is known. For example, it is known that the mechanical strength, heat resistance, heat aging resistance and processability can be improved by producing sulfonamide oligomers and then adding acid dianhydride to produce block polyimide. (For example, refer to Patent Document 1). Also, 1.5 to 2.0 mol of acid dianhydride is added to the diamine in a polar solvent and reacted at a low temperature to synthesize an oligomer of amic acid. Polyimide amide carboxylic acid can be obtained while generating carbon dioxide gas. It is known that a high-performance polyimide film can be produced by casting and heating this (see, for example, Patent Document 2).

  Further, after adding an acid dianhydride to a diaminosiloxane copolymer to obtain a block copolymer of siloxane-amide acid, an equal amount of diamine is added to form a polyamic acid, and then siloxane- Production of an imide block copolymer is disclosed (for example, see Patent Document 3). It is also known to obtain a polyimide-polyorganosiloxane block copolymer using an organic acid catalyst (for example, see Patent Document 4). Moreover, it is known that an adhesive resin composition is obtained from a bicyclooct-ene-tetracarboxylic dianhydride derivative and a bismaleimide compound via a polyamic acid (for example, refer to Patent Document 5).

  However, according to the polyimide production method using the conventional two-stage polycondensation method via the polyamic acid, the produced high molecular weight polyamic acid is thermally unstable and is hydrolyzed by the produced water. There was a problem that the molecular chain was broken by the promotion, and recondensed at the imidization stage to become a random block copolymer. Further, since the high molecular weight polyamic acid produced as an intermediate is easily and quickly exchanged between acid amide groups between molecules, the polyamic acid produced even when two different block copolymers are combined. Exchange reaction cannot be prevented, and not only a random block copolymer is obtained, but also storage stability at room temperature is extremely poor. When applying a polyamic acid solution to the field of liquid crystal devices, for example, minus 30 ° C. There was a problem in use management, such as the necessity of cold-dark storage.

Then, the synthesis method which performs direct imidation of an acid dianhydride and diamine was discovered irrespective of the two-stage polycondensation method (for example, refer patent documents 6-9).
Japanese Patent Publication No. 60-166326. (Page 5) Japanese Patent Publication No. 1-221165 (column 7) JP-A-2-91124 (page 6) US Patent No. 4011279 JP-A-6-41507 (paragraph 0007) JP 2002-155139 A (paragraph 0015) JP 2002-322278 (paragraph 0020) JP 2002-338684 A (paragraph 0020) JP 2003-292779 A (paragraph 0012)

  However, even in these conventional synthesis methods using direct imidization, thermal stability and mechanical strength can be obtained in order to obtain polyimide utilizing the thermal stability and mechanical strength of the acid dianhydride and diamine used. Was insufficient.

  In addition, when polyimide resin is used for an alignment film of STN-LCD (Super Twisted Nematic-Liquid Crystal Display), the time division characteristics of the STN-LCD increases as the twist angle increases, and a high-definition display is possible. As the twist angle increases, stripe domains (light scattering domains) are generated and display defects are likely to occur. In addition, it is empirically known that alignment films with generally higher pretilt angles (angles between liquid crystal molecules and the alignment film interface) can suppress the occurrence of stripe domains. When the cells are aged, the pretilt angle is greatly reduced, and stripe domains and streak-like domains due to rubbing flaws occur.

  Accordingly, an object of the present invention is to provide a polyimide composition utilizing the characteristics of the acid dianhydride and diamine used and a method for producing the same.

  Another object of the present invention is to provide a polyimide composition that can be used for a liquid crystal alignment film in which the pretilt angle does not decrease even when the liquid crystal cell is aged, and generation of stripe domains and streak domains due to rubbing scratches are suppressed. And a manufacturing method thereof.

  In order to achieve the above object, the present invention includes three or more kinds of acid dianhydrides including aromatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride, aromatic diamine and alicyclic diamine. A polyimide composition comprising a polyimide copolymer comprising 6 or more components obtained by reaction with 3 or more kinds of diamines is provided.

  The polyimide copolymer is a block copolymer obtained from an acid dianhydride represented by the following (1), (2) and (3) and a diamine represented by the following (4), (5) and (6). A polymer is preferred.

前記ポリイミド共重合体は、重量平均分子量が５００００〜２０００００であり、イミド化率が７０〜１００％であることが好ましい。

The polyimide copolymer preferably has a weight average molecular weight of 50,000 to 200,000 and an imidization ratio of 70 to 100%.

  It is preferable that the said polyimide copolymer turns into a varnish which has adhesiveness with a glass base material by melt | dissolving in a solvent.

  In order to achieve the above object, the present invention provides a first step in which an alicyclic tetracarboxylic dianhydride (1) and an aromatic diamine (4) are reacted in a heated polar solvent in the presence of a lactone catalyst. A second step in which the aromatic tetracarboxylic dianhydride (2) and the alicyclic diamine (5) are added to the reaction solution obtained in the first step and reacted, and the second step. And a third step of adding the aromatic tetracarboxylic dianhydride (3) and the fluorinated aromatic diamine (6) having a trifluoromethyl group to the reaction solution obtained by the step of reacting at room temperature. A method for producing a polyimide composition is provided.

前記第１、第２および第３のステップによりポリイミド共重合体が得られ、前記ポリイミド共重合体は、重量平均分子量が５００００〜２０００００であり、イミド化率が７０〜１００％であって、液晶配向膜に使用されることが好ましい。

A polyimide copolymer is obtained by the first, second and third steps. The polyimide copolymer has a weight average molecular weight of 50,000 to 200,000, an imidization ratio of 70 to 100%, and a liquid crystal. It is preferably used for an alignment film.

  The polyimide copolymer is dissolved in a solvent to form a varnish having adhesiveness with a glass substrate, and is preferably used for a liquid crystal alignment film.

  A first step of reacting an alicyclic tetracarboxylic dianhydride (1) with an aromatic diamine (4) in a heated polar solvent in the presence of a lactone catalyst, and the first step was obtained. A second step in which the aromatic tetracarboxylic dianhydride (2) and the alicyclic diamine (5) are added to the reaction solution to react, and the reaction solution obtained by the second step is subjected to the aromatic tetracarboxylic acid. And a third step of adding the acid dianhydride (3) and the fluorinated aromatic diamine (6) having a trifluoromethyl group and reacting at room temperature. The polyimide composition is preferably used for a liquid crystal alignment film.

  According to the polyimide composition of the present invention, the dianhydride component and the diamine component are used to form a polyimide, so that the room temperature stability is excellent.

  According to the polyimide copolymer constituting the polyimide composition of the present invention, since it contains a polyimide copolymer of 6 or more components consisting of 3 or more types of acid dianhydrides and 3 or more types of diamines, the characteristics of each component A polyimide composition that makes the best use of can be obtained.

  According to the polyimide copolymer constituting the polyimide composition of the present invention, the polyimide copolymer has a weight average molecular weight of 50,000 to 200,000, an imidization ratio of 70 to 100%, and excellent room temperature stability. Yes.

  According to the polyimide copolymer constituting the polyimide composition of the present invention, since it is a varnish having adhesiveness to a glass substrate, it has excellent room temperature stability.

  According to the method for producing a polyimide composition of the present invention, since imidation is performed with an acid dianhydride component and a diamine component, it is excellent in storage stability at room temperature, and the reaction solution can be used as it is as a varnish. A polyimide composition used for the alignment film can be obtained.

  According to the method for producing a polyimide composition of the present invention, since it is a block copolymer obtained from an aromatic tetracarboxylic dianhydride and an aromatic diamine, a polyimide composition that can be used for a liquid crystal alignment film is obtained. be able to.

  According to the method for producing a polyimide composition of the present invention, acid dianhydride and diamine are directly imidized without going through an intermediate polyamic acid, so that a block copolymer is obtained and excellent in room temperature stability. A polyimide composition that can be used for a liquid crystal alignment film can be obtained.

  According to the method for producing a polyimide composition of the present invention, since a varnish can be directly produced from a raw material by a one-step reaction, it is adjusted to a desired solid content concentration from the raw material charging stage, and the reaction solution is used as it is as a varnish. In addition, since imidization is complete, a polyimide composition having extremely excellent storage stability at room temperature can be obtained.

  In addition, according to the present invention, the storage stability at room temperature is excellent, the reaction solution can be used as it is as a varnish, and the solid content concentration of the varnish can be adjusted to a desired concentration in the raw material charging stage, so that the film thickness and the like can be controlled And can be widely used in the field of liquid crystal devices.

  Furthermore, according to the present invention, even when the liquid crystal cell is aged, the pretilt angle does not decrease, the generation of stripe domains and the occurrence of streak domains due to rubbing scratches can be suppressed, and the imidization rate is high. Since a polyimide-polyamic acid varnish that is a solvent-soluble polyimide and has excellent adhesion and good long-term storage stability can be obtained, a high-quality STN-LCD can be provided.

  In addition, according to the present invention, since the imidization is performed directly in one step by reacting with a lactone-based catalytic polymerization in a polar solvent by heating without passing through the intermediate amic acid, the polyimide composition has the original function. While being held, it can be modified to a resin suitable for the desired application.

  Further, according to the present invention, since the resin composition is composed of 6 or more components, for example, a copolymer having insufficient mechanical strength does not significantly deteriorate other properties by changing or adding one component. It is possible to supplement the mechanical strength.

  Examples of the monocyclic and bicyclic aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, methylpyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride A thing etc. can be mentioned, These can also be used in mixture of 2 or more types.

  Examples of the aromatic diamine of a fluorine compound having one ring and a trifluoromethyl group include 3,5-diaminobenzoic acid, 1,4-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2,5- Dimethyl-1,4-phenylenediamine, 1,3-phenylenediamine, 2-methyl-1,3-phenylenediamine, 4-methyl-1,3-phenylenediamine, 5-methyl-1,3-phenylenediamine, 2 , 2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (3-aminophenyl) Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, and the like. A mixture of more than one species can also be used.

  Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2 , 3,4-Butanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride, bicyclo (2,2,2) oct-7-ene-2,3,5,6 -Tetracarboxylic dianhydride etc. can be mentioned, These can also be used in mixture of 2 or more types.

  Examples of the alicyclic diamine include 3,3-dimethyl-4,4′diamino-dicyclohexylmethane.

  Further, in the liquid crystal device field, for example, in order to achieve dimensional stability of the polyimide alignment film on the substrate, it is necessary to accurately control the coating thickness of the varnish. For this purpose, control of the solid content at the time of varnish preparation and storage stability of the varnish are extremely effective.

  In addition, although the weight molecular weight of resin of this invention prescribes | regulates 50,000-200,000, Preferably it is 70-150,000. If it is 50,000 or less, for example, when the solid content concentration is diluted to 5%, the film-forming property is inferior. Conversely, if it is 200,000 or more, the storage stability accompanying gelation of the varnish is inferior. The imidization ratio of the resin of the present invention is specified to be 70% or more, preferably 85 to 100%. If it is less than 70%, the stability such as viscosity change due to storage at room temperature decreases.

  In addition, the polar solvent is not particularly defined, but examples include N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, sulfolane, anisole, dioxolane, butyl cellosolve acetate, and gamma butyrolactone. These can be used in combination of two or more.

  Examples of the lactone catalyst other than γ-caprolactone include γ-valerolactone, γ-butyrolactone, γ-tetronic acid, γ-phthalide, γ-coumarin, and γ-phthalido acid. When used as a mixture of this lactone catalyst and a base such as pyridine, quinoline, N-methylmorpholine, the mixing ratio is preferably 1/1 to / 3 in terms of molecular weight ratio.

  A condenser tube with a ball equipped with a trap with a silicon cock was attached to a 1000 ml separable three-necked flask equipped with a stirrer. 9.93 g of bicyclo (2,2,2) oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (1) (hereinafter referred to as “BCD”) and 3,5-diaminobenzoic acid (4) 9.13 g (hereinafter referred to as “DABz”), 1.37 g of γ-caprolactone, 1.9 g of pyridine, 123 g of NMP, and 30 g of toluene were added, and the mixture was stirred at room temperature in a nitrogen atmosphere for 10 minutes, and then raised to 170 ° C. The mixture was stirred at 180 rpm for 1 hour.

次に、この反応液を一昼夜空冷し、３，３’，４，４’−ビフェニルテトラカルボン酸二無水物（２）（以下「ＢＰＤＡ」という）２３．５４ｇ、３，３’−ジメチル−４，４'−ジアミノジシクロヘキシルメタン（５）（以下「ＤＭＨＭ」という）１４．４７ｇ、ＮＭＰ１６０ｇ、トルエン８２．５ｇを入れて、再び１７０℃に昇温、５時間反応させた。回転数は１８０ｒｐｍとし、反応が進行するに従い１００ｒｐｍ、５０ｒｐｍと適宜低下させた。この後、ピロメリット酸二無水物（３）（以下「ＰＭＤＡ」という）６．１ｇ、２、２−ビス[４−（４−アミノフェノキシ）フェニル]ヘキサフルオロプロパン（６）（以下「ＨＦ−ＢＡＰＰ」という）１４．５２ｇおよびＮＭＰ１２３ｇを加え、室温雰囲気中で１８０ｒｐｍにて４時間撹拌反応後、９０℃に昇温、７０ｒｐｍで１時間撹拌のクッキング処理を行いワニスを作製した。

Next, this reaction solution was air-cooled all day and night, and 23.54 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (2) (hereinafter referred to as “BPDA”), 3,3′-dimethyl-4 , 4′-diaminodicyclohexylmethane (5) (hereinafter referred to as “DMHM”) 14.47 g, NMP 160 g, and toluene 82.5 g were added, and the mixture was again heated to 170 ° C. and reacted for 5 hours. The number of revolutions was 180 rpm, and as the reaction proceeded, the speed was appropriately reduced to 100 rpm and 50 rpm. Thereafter, pyrogellitic dianhydride (3) (hereinafter referred to as “PMDA”) 6.1 g, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (6) (hereinafter referred to as “HF-”) 14.52 g (referred to as “BAPP”) and 123 g of NMP were added, stirred at 180 rpm for 4 hours in a room temperature atmosphere, then heated to 90 ° C. and stirred for 1 hour at 70 rpm to prepare a varnish.

なお、作製したワニスの初期重量分子量（Ｍｗ）をＧＰＣで調べたところ、Ｍｗ＝８５，０００であった。さらにワニスを２００℃、２時間加熱して固形分濃度を調べたところ１５．１％であった。

In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated by GPC, it was Mw = 85,000. Furthermore, when the varnish was heated at 200 ° C. for 2 hours and the solid content concentration was examined, it was 15.1%.

  Immediately after diluting the varnish produced as described above with N-vinyl-2-pyrrolidone and butyl cellosolve acetate to a solid content concentration of 5.0%, after storage at room temperature for 1 month and after storage at room temperature for 3 months The stability was evaluated by the change in measurement data of the pretilt angle measurement cell produced using the above varnish and the change in pretilt angle after cell aging. Further, the rubbing treatment was performed based on the adhesion to the glass substrate and the rubbing scratch at the time of producing the pretilt angle measurement cell. The results are shown in Table 1.

  Similarly to Example 1, a ball condenser having a trap with a silicon cock was attached to a 1000 ml separable three-necked flask equipped with a stirrer. BCD9.93 g and DABz 9.13 g, further γ-caprolactone 1.37 g, pyridine 1.9 g, NMP 123 g and toluene 30 g were added and stirred at room temperature in a nitrogen atmosphere for 10 minutes, then heated to 180 ° C. and 180 rpm for 1 hour. Stir.

  Next, this reaction solution was air-cooled all day and night, 23.54 g of BPDA, 14.47 g of DMHM, 160 g of NMP, and 82.5 g of toluene were added, and the temperature was raised again to 180 ° C. and reacted for 7 hours. The number of revolutions was 180 rpm, and as the reaction proceeded, the speed was appropriately reduced to 100 rpm and 50 rpm. After this, 4.36 g of PMDA, 10.37 g of HF-BAPP and 106 g of NMP were added, and after stirring reaction at 180 rpm for 4 hours in a room temperature atmosphere, cooking was performed by heating to 90 ° C. and stirring for 1 hour at 70 rpm to prepare a varnish. .

  In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated by GPC, it was Mw = 145,000. Furthermore, when the varnish was heated at 200 ° C. for 2 hours and the solid content concentration was examined, it was 15.5%.

  Immediately after diluting the varnish produced as described above with N-vinyl-2-pyrrolidone and butyl cellosolve acetate to a solid content concentration of 4.5%, after storage at room temperature for 1 month and after storage at room temperature for 3 months The stability was evaluated by the change in measurement data of the pretilt angle measurement cell produced using the above varnish and the change in pretilt angle after cell aging. Furthermore, the adhesiveness with the glass substrate was determined by rubbing treatment during the production of the pretilt angle measurement cell. The results are shown in Table 1.

  Similarly to Example 1, a ball condenser having a trap with a silicon cock was attached to a 1000 ml separable three-necked flask equipped with a stirrer. BCD9.93 g and DABz 9.13 g, further γ-caprolactone 1.37 g, pyridine 1.9 g, NMP 123 g and toluene 30 g were added and stirred at room temperature in a nitrogen atmosphere for 10 minutes, then heated to 180 ° C. and 180 rpm for 1 hour. Stir.

  Next, this reaction solution was air-cooled all day and night, PMDA 17.44 g, DMHM 14.47 g, NMP 160 g, and toluene 82.5 g were added, and the temperature was raised again to 180 ° C. and reacted for 6 hours. The number of revolutions was 180 rpm, and as the reaction proceeded, the speed was appropriately reduced to 100 rpm and 50 rpm. In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated using GPC, it was Mw = 80,000. Thereafter, 6.1 g of PMDA, 14.52 g of HF-BAPP and 106 g of NMP were added, and after stirring reaction at 180 rpm in a room temperature atmosphere for 4 hours, cooking was performed by heating to 90 ° C. and stirring for 1 hour at 70 rpm to prepare a varnish. .

  In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated by GPC, it was Mw = 110,000. Furthermore, when the varnish was heated at 200 ° C. for 2 hours and the solid content concentration was examined, it was 15.3%.

  Immediately after diluting the varnish produced as described above with N-vinyl-2-pyrrolidone and butyl cellosolve acetate to a solid content concentration of 4.5%, after storage at room temperature for 1 month and after storage at room temperature for 3 months The stability was evaluated based on the change in measurement data of the pretilt angle measurement cell produced using the above varnish and the change in bletilt angle after cell aging. Furthermore, the adhesiveness with the glass substrate was determined by rubbing treatment during the production of the pretilt angle measurement cell. The results are shown in Table 1.

  Similarly to Example 1, a ball-mounted condenser equipped with a trap with a silicon cock was attached to a 1000 ml separable three-necked flask sung with a stirrer. BCD9.93 g and DABz 4.56 g, 1,4-phenylenediamine 3.24 g, γ-caprolactone 1.37 g, pyridine 1.9 g, NMP 123 g, and toluene 30 g were added and stirred at room temperature in a nitrogen atmosphere for 10 minutes. The temperature was raised to 180 ° C., and the mixture was stirred at 180 rpm for 1 hour.

  Next, this reaction solution was air-cooled all day and night, 23.54 g of BPDA, 14.47 g of DMHM, 160 g of NMP, and 82.5 g of toluene were added, and the temperature was raised again to 180 ° C. and reacted for 6 hours. The number of revolutions was 180 rpm, and as the reaction proceeded, the speed was appropriately reduced to 100 rpm and 50 rpm. Thereafter, 4.36 g of PMDA, 10.37 g of HF-BAPP, and 106 g of NMP were added, and after stirring reaction at 180 rpm for 4 hours in a room temperature atmosphere, cooking was performed by heating to 90 ° C. and stirring for 1 hour at 70 rpm to prepare a varnish. .

  In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated by GPC, it was Mw = 90,000. Furthermore, when the varnish was heated at 200 ° C. for 2 hours and the solid content concentration was examined, it was 15.1%.

Immediately after diluting the varnish produced as described above with N-vinyl-2-pyrrolidone and butyl cellosolve acetate to a solid content concentration of 4.5%, after storage at room temperature for 1 month and after storage at room temperature for 3 months The stability was evaluated by the change in measurement data of the pretilt angle measurement cell produced using the above varnish and the change in pretilt angle after cell aging. Furthermore, the adhesiveness with the glass substrate was determined by rubbing treatment during the production of the pretilt angle measurement cell. The results are shown in Table 1.
(Comparative Example 1)
Similarly to Example 1, a ball condenser having a trap with a silicon cock was attached to a 1000 ml separable three-necked flask equipped with a stirrer. BCD9.93 g and DABz 9.13 g, further γ-caprolactone 1.37 g, pyridine 1.9 g, NMP 123 g and toluene 30 g were added and stirred at room temperature in a nitrogen atmosphere for 10 minutes, then heated to 180 ° C. and 180 rpm for 1 hour. Stir.

  Next, this reaction solution was air-cooled all day and night, 23.54 g of BPDA, 14.47 g of DMHM, 160 g of NMP, and 82.5 g of toluene were added, and the temperature was raised again to 180 ° C. and reacted for 7 hours. The number of revolutions was 180 rpm, and as the reaction proceeded, the speed was appropriately reduced to 100 rpm and 50 rpm. In addition, when the initial weight molecular weight (Mw) of the produced varnish was investigated using GPC, it was Mw = 100,000.

Immediately after diluting the varnish produced as described above with N-vinyl-2-pyrrolidone and butyl cellosolve acetate to a solid content concentration of 5.0%, after storage at room temperature for 1 month and after storage at room temperature for 3 months The stability was evaluated by the change in measurement data of the pretilt angle measurement cell produced using the above varnish and the change in pretilt angle after cell aging. Furthermore, the adhesiveness with the glass substrate was determined by rubbing treatment during the production of the pretilt angle measurement cell. The results are shown in Table 1.
(Comparative Example 2)
Change in measurement data of cell for pretilt angle measurement due to difference in room temperature storage period of varnish used, varnish for liquid crystal alignment film material manufactured by NISSAN CHEMICAL INDUSTRY CO., LTD., SANEVER (registered trademark) SE-3140, and pretilt angle after cell aging Stability was evaluated by change. Furthermore, the adhesiveness with the glass substrate was determined by rubbing treatment during the production of the pretilt angle measurement cell. The results are shown in Table 1.

Ａ．表１に示したワニスおよび各フィルムの諸特性は以下の方法により評価した。
（１）重量平均分子量（Ｍｗ）
ワニスの初期分子量常温１ケ月、常温３ケ月及び常温６ケ月放置後の分子量測定は、東ソー株式会社製のデガッサー（ＳＣ−８０２０）、デュアルポンプ（ＣＣＰＳ）、および紫外可視検出器（ＵＶ８０２０）から成るＧＰＣ装置を用いた。また、カラムはＴＳＫ−ＧＥＬ ＧＭＨＨＲ−Ｍとした。
（２）Ｅ型粘度測定
ワニスの初期、常温１ケ月、及び常温３ケ月放置後の粘度測定をトキメック製ＴＶＥ−２０ＨＴ粘度計を用い、ロータ０．８×Ｒ２４により、ロータ回転３０ｒｐｍ、試料量０．５ｍｌで実測し、５回の平均値を求めた。
Ｂ．プレチルト角測定用セルの作製手順および光学特性評価
（１）プレチルト角測定用セルの作製工程
プレチルト角測定用セル作製工程を下記に示す。まず、準備した試験用ガラス基板を良く洗浄・乾燥した後、濃度５％に希釈した本発明の実施の形態のポリイミドワニスを専用の転写塗工機（オングストローマ）を用い、５００Å程度となるように塗工し、熱風循環式の乾燥炉にて硬化させる。次に、専用のラピング装置によりラビング、洗浄の後、シール剤の印刷を行なった。上下の基板をギャップ５０μ厚のカプトンスペーサを介して、平行にエポキシ系接着剤で貼合わせ後、乾燥し真空液晶注入を行ない、注入口をＵＶ硬化形接着剤で封止し、プレチルト角測定用セルを作製した。
（２）プレチルト角評価（安定性）
作製したプレチルト角測定用セルを中央精機株式会社製ＯＭＳシリーズのクリスタルローテション法によるプレチルト角測定装置を用い、波長６３３ｎｍにてＮ＝５点測定した。ここで、ワニスの常温保存期間の違いによるプレチルト角測定用セルの測定データ変化、及びセルエージング後（１００℃／１ｈ）のプレチルト角変化で安定性を評価した。
（３）密着性評価
上記に示すセル作製工程において、配向膜を１軸延伸するラビング処理（布で配向膜表面を擦る工程）後の、膜の剥離の有無により密着性を評価した。なお、剥離や傷の有無は、目視観察、及び光学顕微鏡観察により判定した。

A. Various characteristics of the varnish and each film shown in Table 1 were evaluated by the following methods.
(1) Weight average molecular weight (Mw)
The initial molecular weight of the varnish is measured at room temperature for 1 month, at room temperature for 3 months and at room temperature for 6 months, and consists of a degasser manufactured by Tosoh Corporation (SC-8020), a dual pump (CCPS), and an ultraviolet-visible detector (UV8020). A GPC device was used. The column was TSK-GEL GMHHR-M.
(2) E-type viscosity measurement The initial measurement of the varnish, the viscosity after standing at room temperature for 1 month, and room temperature for 3 months was measured using a TVE-20HT viscometer manufactured by Tokimec, with a rotor rotation of 30 rpm and a sample amount of 0 using a rotor 0.8 × R24. Measured at 5 ml, the average of 5 times was determined.
B. Pretilt angle measurement cell fabrication procedure and optical characteristic evaluation (1) Pretilt angle measurement cell fabrication process The pretilt angle measurement cell fabrication process is described below. First, after thoroughly cleaning and drying the prepared test glass substrate, the polyimide varnish according to the embodiment of the present invention diluted to a concentration of 5% is used with an exclusive transfer coating machine (Angstroma) so that the thickness becomes about 500 mm. And cured in a hot air circulating drying oven. Next, the sealant was printed after rubbing and washing with a dedicated lapping device. Paste the upper and lower substrates in parallel with an epoxy adhesive through a Kapton spacer with a gap of 50μ, then dry and inject vacuum liquid crystal, seal the injection port with UV curable adhesive, and measure the pretilt angle A cell was produced.
(2) Pretilt angle evaluation (stability)
N = 5 points were measured for the prepared pretilt angle measurement cell at a wavelength of 633 nm using a pretilt angle measuring device based on the crystal rotation method of OMS series manufactured by Chuo Seiki Co., Ltd. Here, the stability was evaluated by the change in measurement data of the pretilt angle measurement cell due to the difference in the storage temperature of the varnish at normal temperature and the change in the pretilt angle after cell aging (100 ° C./1 h).
(3) Adhesive evaluation In the cell production process shown above, the adhesiveness was evaluated by the presence or absence of film peeling after rubbing treatment (step of rubbing the alignment film surface with a cloth) for uniaxially stretching the alignment film. The presence or absence of peeling or scratches was determined by visual observation and optical microscope observation.

Claims (8)

  Obtained by reaction of three or more types of acid dianhydrides including aromatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride with three or more types of diamine including aromatic diamine and alicyclic diamine. A polyimide composition comprising a polyimide copolymer comprising 6 or more components. The polyimide copolymer includes an acid dianhydride represented by the following (1), (2) and (3):
The polyimide composition according to claim 1, which is a block copolymer obtained from the diamine represented by the following (4), (5) and (6).

  The polyimide composition according to claim 1, wherein the polyimide copolymer has a weight average molecular weight of 50,000 to 200,000 and an imidization ratio of 70 to 100%.   The polyimide composition according to claim 1, wherein the polyimide copolymer becomes a varnish having an adhesive property with a glass substrate by being dissolved in a solvent. A first step of reacting an alicyclic tetracarboxylic dianhydride (1) with an aromatic diamine (4) in a heated polar solvent in the presence of a lactone catalyst;
A second step of adding and reacting the aromatic tetracarboxylic dianhydride (2) and the alicyclic diamine (5) to the reaction solution obtained by the first step;
A third step of adding an aromatic tetracarboxylic dianhydride (3) and a fluorinated aromatic diamine (6) having a trifluoromethyl group to the reaction solution obtained in the second step and reacting at room temperature. The manufacturing method of the polyimide composition characterized by including.

  A polyimide copolymer is obtained by the first, second and third steps. The polyimide copolymer has a weight average molecular weight of 50,000 to 200,000, an imidization ratio of 70 to 100%, and a liquid crystal. 6. The method for producing a polyimide composition according to claim 5, which is used for an alignment film.   The said polyimide copolymer becomes a varnish which has adhesiveness with a glass base material by melt | dissolving in a solvent, and is used for a liquid crystal aligning film, The manufacturing method of the polyimide composition of Claim 5 characterized by the above-mentioned. A first step of reacting an alicyclic tetracarboxylic dianhydride (1) with an aromatic diamine (4) in a heated polar solvent in the presence of a lactone catalyst;
A second step of adding and reacting the aromatic tetracarboxylic dianhydride (2) and the alicyclic diamine (5) to the reaction solution obtained by the first step;
A third step of adding an aromatic tetracarboxylic dianhydride (3) and a fluorinated aromatic diamine (6) having a trifluoromethyl group to the reaction solution obtained in the second step and reacting at room temperature. A method for producing a polyimide composition, comprising:
The said polyimide composition is used for a liquid crystal aligning film, The manufacturing method of the polyimide composition characterized by the above-mentioned.