JP2012036382A - Polyimide precursor aqueous solution composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide precursor aqueous solution composition in which environmental adaptability is good by using a water solvent, and moreover since the aromatic polyimide obtained using the same has high crystallinity, it is excellent in characteristics such as heat resistance, mechanical strength, an electrical property, and solvent resistance.SOLUTION: The polyimide precursor aqueous solution composition comprises dissolving a polyamic acid consisting of a repeating unit expressed by chemical formula (1) with imidazoles which have two or more alkyl groups as a substituent of at least 1.6 times moles to the tetracarboxylic acid component of the polyamic acid into a water solvent. In the chemical formula (1), A is a tetravalent group based on tetracarboxylic acid, B is a group based on an aromatic diamine, and the solubility to water at 25°C of the aromatic diamine is at least 0.1 g/L.

Description

  The present invention relates to a polyimide precursor aqueous solution composition. This polyimide precursor aqueous solution composition is preferable because it has higher environmental adaptability than a polyimide precursor solution composition using an organic solvent. Moreover, the aromatic polyimide obtained by using this polyimide precursor aqueous solution composition has high crystallinity, and thus has excellent characteristics such as heat resistance, mechanical strength, electrical characteristics, and solvent resistance.

  Aromatic polyimides obtained from aromatic tetracarboxylic dianhydrides and aromatic diamines have excellent heat resistance, mechanical strength, electrical properties, solvent resistance, and other properties, so they are widely used in the electrical and electronics industries. ing. However, since aromatic polyimides have poor solubility in organic solvents, a solution composition in which a polyimide precursor polyamic acid is dissolved in an organic solvent is usually applied onto a substrate surface, and then heated at a high temperature. Thus, aromatic polyimide is obtained by dehydration ring closure (imidization). Since this polyamic acid solution composition uses an organic solvent or requires high-temperature heat treatment, it is not necessarily suitable for the environment, and its use may be limited in some cases.

  For this reason, water-soluble polyimide precursors have been proposed. For example, in Patent Document 1, the polyamic acid obtained in an organic solvent is hydrolyzed and then poured into water to obtain a polyamic acid powder. The polyamic acid powder is further pulverized and washed in warm water, It has been proposed to obtain an aqueous polyamic acid salt composition by mixing with water and specific amine compounds such as 2-methylaminodiethanol. However, this polyamic acid salt aqueous solution composition is difficult to achieve a high molecular weight, and there is room for improvement in the properties of the resulting polyimide.

  Further, Patent Document 2 discloses a water-soluble polyimide obtained by separation from a reaction mixture of a polyamic acid obtained in an organic solvent and 1,2-dimethylimidazole and / or 1-methyl-2-ethylimidazole. Precursors have been proposed. However, in the water-soluble polyimide precursor specifically proposed here, the aromatic polyimide obtained using the precursor is amorphous. Furthermore, here, the water-soluble polyimide precursor is prepared in an organic solvent, then separated and dissolved in an aqueous solvent, but the organic solvent is completely removed from the water-soluble polyimide precursor prepared in the organic solvent. Since it cannot be performed (imidation occurs when heat treatment is performed to completely remove it), there is a problem that an organic solvent is accompanied in the aqueous solution composition.

JP-A-8-59832 JP 2002-226582 A

  Therefore, the object of the present invention is that the environmental adaptability is good by using an aqueous solvent, and the aromatic polyimide obtained by using it has high crystallinity, and therefore has heat resistance, mechanical strength, An object is to provide a polyimide precursor aqueous solution composition having excellent characteristics such as electric characteristics and solvent resistance, preferably having a high molecular weight and containing no organic solvent other than water.

  The present invention relates to the following items.

1. A polyamic acid comprising a repeating unit represented by the following chemical formula (1) obtained by reacting a tetracarboxylic acid component and a diamine component is 1.6 times mol or more with respect to the tetracarboxylic acid component of the polyamic acid. A polyimide precursor aqueous solution composition dissolved in an aqueous solvent together with imidazoles having two or more alkyl groups as substituents.

化学式（１）において、Ａは、２〜３個の芳香族環を有するテトラカルボン酸からカルボキシル基を除いた４価の基であり、Ｂは、１〜２個の芳香族環を有する芳香族ジアミンからアミノ基を除いた２価の基であって、前記芳香族ジアミンの２５℃における水に対する溶解度が０．１ｇ／Ｌ以上である。

In the chemical formula (1), A is a tetravalent group obtained by removing a carboxyl group from a tetracarboxylic acid having 2 to 3 aromatic rings, and B is an aromatic having 1 to 2 aromatic rings. A divalent group obtained by removing an amino group from a diamine, and the solubility of the aromatic diamine in water at 25 ° C. is 0.1 g / L or more.

2. Imidazoles having two or more alkyl groups as substituents are from 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, and 1-methyl-4-ethylimidazole. The polyimide precursor aqueous solution composition according to claim 1, which is an imidazole selected from the group consisting of:

3. Item 3. The polyimide precursor aqueous solution composition according to Item 1 or 2, wherein A in the chemical formula (1) is the following chemical formulas (2) to (7) or a mixture thereof.

4). Item 4. The polyimide precursor aqueous solution composition according to any one of Items 1 to 3, wherein B in the chemical formula (1) is the following chemical formulas (8) to (9) or a mixture thereof.

5. Item 5. The polyimide precursor aqueous solution composition according to any one of Items 1 to 4, which has a logarithmic viscosity of 0.2 or more.

6). Item 6. The polyimide precursor aqueous solution composition according to any one of Items 1 to 5, wherein the content of the organic solvent is less than 5%.

7). Item 7. The polyimide precursor aqueous solution composition according to any one of Items 1 to 6, wherein the aqueous solvent contains substantially no organic solvent other than water.

According to the present invention, the environmental adaptability is good by using an aqueous solvent, and the aromatic polyimide obtained by using the water solvent has high crystallinity, so that it has heat resistance, mechanical strength, electrical properties, resistance to resistance. It is possible to provide a polyimide precursor aqueous solution composition having excellent solvent properties and the like, preferably having a high molecular weight and containing no organic solvent other than water.
Aromatic polyimide obtained from the polyimide precursor aqueous solution composition of the present invention has excellent heat resistance, mechanical strength, electrical properties, solvent resistance, and other precision devices such as electric / electronic devices and copying machines. For example, it can be suitably used as various parts such as a flexible printed wiring board, a seamless belt for intermediate transfer, fixing, or conveyance of a copying machine. In addition, since the degree of swelling is small even in a battery environment and it has excellent toughness, it can be suitably used for battery electrode binder applications.

  The polyamic acid which comprises the polyimide precursor aqueous solution composition of this invention consists of a repeating unit represented by the said Chemical formula (1).

  A in the chemical formula (1) is a tetravalent group obtained by removing a carboxyl group from a tetracarboxylic acid having 2 to 3 aromatic rings, preferably the chemical formulas (2) to (7) or a mixture thereof. It is. That is, the tetracarboxylic acid component of the polyamic acid used in the present invention is a tetracarboxylic acid (tetracarboxylic acid, dianhydride or esterified product thereof) having 2 to 3 aromatic rings, for example, 3, 3 ′, 4,4′-biphenyltetracarboxylic acids, 2,3,3 ′, 4′-biphenyltetracarboxylic acids, 2,2 ′, 3,3′-biphenyltetracarboxylic acids, 4,4′-oxydiphthalic acids 3,3 ′, 4,4′-benzophenone tetracarboxylic acids, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic acids, p-terphenyl tetracarboxylic acids, m-terphenyl tetracarboxylic acids, and the like, and A mixture thereof can be preferably exemplified. Among these, 3,3 ′, 4,4′-biphenyltetracarboxylic acids, 3,3 ′, 4,4′-benzophenonetetracarboxylic acids, and 4,4′-oxydiphthalic acids are preferable. 4,4′-biphenyltetracarboxylic acids, 4,4′-oxydiphthalic acids, and mixtures thereof are more preferred. If a tetracarboxylic acid component other than these is used, it may be difficult to obtain a water-soluble polyimide precursor, or the crystallinity of the resulting polyimide may be reduced, and high characteristics may not be obtained.

B in the chemical formula (1) is a divalent group obtained by removing an amino group from an aromatic diamine having 1 to 2 aromatic rings, and the solubility of the aromatic diamine in water at 25 ° C. is 0. 1 g / L or more. That is, the aromatic diamine component of the polyamic acid used in the present invention is an aromatic diamine having 1 to 2 aromatic rings, and the solubility of the aromatic diamine in water at 25 ° C. is 0.1 g / L or more. Is.
When the aromatic diamine has more than two aromatic rings, since the aromatic diamine molecule usually contains a plurality of highly flexible bonds, the aromatic polyimide obtained from such an aromatic diamine is crystalline. It becomes difficult to obtain high characteristics due to a decrease in properties.
Further, the solubility of the aromatic diamine in water at 25 ° C. is 0.1 g / L or more, which is a particularly necessary characteristic for obtaining a polyimide precursor aqueous solution composition, and the solubility in water is 0.1 g / L. If it is less than L, it is difficult to obtain a uniformly dissolved polyimide precursor aqueous solution composition, which is not preferable.

Examples of the aromatic diamine component used in the present invention include p-phenylenediamine (the solubility in water at 25 ° C. is 120 g / L, the same applies hereinafter), m-phenylenediamine (77 g / L), 4,4′-diaminodiphenyl ether (0 19 g / L), 3,4′-diaminodiphenyl ether (0.24 g / L), 4,4′-diaminodiphenylmethane (0.54 g / L), 2,4-toluenediamine (62 g / L), 3, 3′-dihydroxy-4,4′-diaminobiphenyl (1.3 g / L), bis (4-amino-3-carboxyphenyl) methane (200 g / L), 2,4-TDA: 2,4-diaminotoluene (62 g / L) and the like. However, since the water-soluble property and the crystallinity of the resulting polyimide are high and excellent characteristics can be obtained, p-Fe Range amine, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, and mixtures thereof are preferred, and p-phenylenediamine, 4,4′-diaminodiphenyl ether, and mixtures thereof are more preferred. More preferred.
In addition, the solubility with respect to the water in 25 degreeC means the limit amount (g) which the said substance melt | dissolves in 1 L (liter) of water of 25 degreeC. This value can be easily searched by SciFinder (registered trademark) known as a search service based on a beta base such as a chemical abstract. Here, among the solubility under various conditions, the value at pH 7 calculated by Advanced Chemistry Development (ACD / Labs) Software V11.02 (Copyright 1994-2011 ACD / Labs) was adopted.

  As the imidazole (compound) having two or more alkyl groups as a substituent used in the present invention, a compound represented by the following chemical formula (10) is preferable.

化学式（１０）において、Ｘ_１〜Ｘ_４は、それぞれ独立に、水素原子、或いは炭素数が１〜５のアルキル基であって、Ｘ_１〜Ｘ_４のうち少なくとも２個は炭素数が１〜５のアルキル基である。

In the chemical formula (10), X _{1 to} X ₄ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and at least two of X _{1 to} X ₄ have _{1 to} C carbon atoms. 5 alkyl groups.

Since imidazoles having two or more alkyl groups as a substituent have high solubility in water, a polyimide precursor composition can be easily produced by using them. As these imidazoles, 1,2-dimethylimidazole (solubility in water at 25 ° C. is 239 g / L, hereinafter the same), 2-ethyl-4-methylimidazole (1000 g / L), 4-ethyl-2-methyl Imidazole (1000 g / L), 1-methyl-4-ethylimidazole (54 g / L), and the like are preferable.
In addition, the solubility with respect to the water in 25 degreeC means the limit amount (g) which the said substance melt | dissolves in 1 L (liter) of water of 25 degreeC. This value can be easily searched by SciFinder (registered trademark) known as a search service based on a beta base such as a chemical abstract. Here, among the solubility under various conditions, the value at pH 7 calculated by Advanced Chemistry Development (ACD / Labs) Software V11.02 (Copyright 1994-2011 ACD / Labs) was adopted.

The amount of the imidazole having two or more alkyl groups as a substituent used in the present invention is preferably 0 with respect to the carboxyl group of the polyamic acid generated by the reaction of the raw material tetracarboxylic dianhydride and diamine. More than 8 times equivalent, More preferably, it is 1.0 times equivalent or more, More preferably, it is 1.2 times equivalent or more. If the amount of imidazole used is less than 0.8 equivalents relative to the carboxyl group of the polyamic acid, it may not be easy to obtain a uniformly dissolved polyimide precursor aqueous solution composition. Moreover, although the upper limit of the usage-amount of imidazoles is not specifically limited, Usually, it is less than 10 times equivalent, Preferably it is less than 5 times equivalent, More preferably, it is less than 3 times equivalent. If the amount of imidazole used is too large, it may be uneconomical and the storage stability of the composition may be deteriorated.
In the present invention, the double equivalent to the carboxyl group of the polyamic acid that defines the amount of imidazoles is the number (number of molecules) of imidazoles in one carboxyl group that forms the amic acid group of the polyamic acid. Indicates whether to use. Note that the number of carboxyl groups forming the amic acid group of the polyamic acid is calculated as forming two carboxyl groups per molecule of the starting tetracarboxylic acid component.
Therefore, the amount of the imidazoles used in the present invention is preferably 1.6 times mol or more, more preferably 2 with respect to the tetracarboxylic acid component of the polyamic acid, that is, with respect to the raw material tetracarboxylic dianhydride. It is 0.0 times mol or more, More preferably, it is 2.4 times mol or more.

  The characteristics of imidazoles used in the present invention are not only to increase the solubility in water by forming a salt with a carboxyl group of polyamic acid, but also when imidizing (dehydrating cyclization) the polyimide precursor into a polyimide, It has an extremely high catalytic action. As a result, when the polyimide precursor aqueous solution composition of the present invention is used, an aromatic polyimide having extremely high physical properties can be easily obtained, for example, by a heat treatment at a lower temperature for a shorter time.

The polyimide precursor aqueous solution composition of the present invention conforms to the methods of Patent Documents 1 and 2,
(i) Polyamic acid obtained by reacting a tetracarboxylic acid component with a diamine component using an organic solvent as a reaction solvent is poured into water to obtain a polyamic acid powder, and the polyamic acid powder is imidazoles in an aqueous solvent. (Preferably a method of obtaining an aqueous solution composition by mixing and dissolving together with imidazoles having two or more alkyl groups),
(ii) A water-soluble polyimide precursor is obtained by reacting a tetracarboxylic acid component and a diamine component in the presence of imidazoles (preferably imidazoles having two or more alkyl groups) using an organic solvent as a reaction solvent, A method of dissolving it in an aqueous solvent after separating it, or
(iii) A polyamic acid is obtained by reacting a tetracarboxylic acid component and a diamine component using an organic solvent as a reaction solvent, and the polyamic acid is converted into an imidazole (preferably two or more alkyl groups) using the organic solvent as a reaction solvent. It can also be obtained by a method in which a water-soluble polyimide precursor is obtained by reacting with an imidazole having a solvent, and is separated and then dissolved in an aqueous solvent. However, as described above, it is not preferable to prepare the polyimide precursor in an organic solvent in order to obtain a polyimide precursor aqueous solution composition having an extremely small organic solvent content and further not containing an organic solvent.

  The polyimide precursor aqueous solution composition of the present invention preferably reacts a tetracarboxylic acid component with an aromatic diamine component in the presence of imidazoles having two or more alkyl groups as substituents using water as a reaction solvent. By doing so, it is possible to manufacture very simply (directly).

This reaction is carried out at a relatively low temperature of 100 ° C. or less, preferably 80 ° C. or less in order to suppress the imidization reaction, using approximately equimolar amounts of a tetracarboxylic acid component and an aromatic diamine component. Although not limited, the normal reaction temperature is 25 ° C to 100 ° C, preferably 40 ° C to 80 ° C, more preferably 50 ° C to 80 ° C, and the reaction time is about 0.1 to 24 hours, preferably Is preferably about 2 to 12 hours. By setting the reaction temperature and reaction time within the above ranges, a high-molecular weight polyimide precursor aqueous solution composition can be easily obtained with high production efficiency. The reaction may be carried out in an air atmosphere, but usually it is suitably carried out in an inert gas, preferably a nitrogen gas atmosphere.
Further, the substantially equimolar amount of the tetracarboxylic acid component and the aromatic diamine component specifically refers to a molar ratio [tetracarboxylic acid component / diamine component] of about 0.90 to 1.10, preferably 0.95 to 1. .05 or so.

  In the polyimide precursor aqueous solution composition of the present invention, the logarithmic viscosity measured at a temperature of 30 ° C. and a concentration of 0.5 g / 100 mL (dissolved in water) based on the solid content concentration resulting from the polyimide precursor (substantially polyamic acid). Is 0.2 or more, preferably 0.4 or more, more preferably 0.6 or more, still more preferably 0.8 or more, and particularly preferably 1.0 or more, or a high molecular weight. When the logarithmic viscosity is lower than the above range, the molecular weight of the polyimide precursor is low, so that it is difficult to obtain an aromatic polyimide having high characteristics even when using the polyimide precursor aqueous solution composition of the present invention. There is.

  The polyimide precursor aqueous solution composition of the present invention uses an aqueous solvent, but a known organic solvent used when preparing a polyamic acid other than water is 50% by mass or less, preferably 30% by mass or less, based on the total solvent. Preferably, you may use in the ratio of 10 mass% or less.

  “Water as a reaction solvent” means that water is used as a main component of the solvent. Therefore, an organic solvent other than water may be used in a proportion of 50% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less in the total solvent. The organic solvent mentioned here does not include tetracarboxylic acid components such as tetracarboxylic dianhydride, diamine components, polyimide precursors such as polyamic acid, and imidazoles.

  Examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl- 2-imidazolidinone, N-methylcaprolactam, hexamethylphosphorotriamide, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, tetrahydrofuran, bis [ 2- (2-methoxyethoxy) ethyl] ether, 1,4-dioxane, dimethyl sulfoxide, dimethyl sulfone, diphenyl ether, sulfolane, diphenyl sulfone, tetramethyl urea, anisole, m-cresol, phenol, γ-butyrolactone, and the like. .

  In the manufacturing method of the polyimide precursor aqueous solution composition of the present invention, since the environmental adaptability is high, the reaction solvent is preferably a solvent having an organic solvent content of less than 5%, and an organic solvent other than water is used. It is particularly preferable that the aqueous solvent does not contain. The composition of the reaction solvent can be appropriately selected according to the desired solvent composition of the polyimide precursor aqueous solution composition to be produced, and may be preferably the same as the desired solvent composition of the polyimide precursor aqueous solution composition. .

In the polyimide precursor aqueous solution composition of the present invention, the solid content concentration resulting from the polyimide precursor (substantially polyamic acid) is not limited, but is preferably 5 mass with respect to the total amount of the polyimide precursor and the solvent. % To 45% by mass, more preferably 7% to 40% by mass, and still more preferably 9% to 30% by mass. If the solid content concentration is lower than 5% by mass, the productivity may be remarkably deteriorated, and if it is higher than 45% by mass, the fluidity of the solution may be lost. The solution viscosity at 30 ° C. of the polyimide precursor aqueous solution composition of the present invention is not limited, but is preferably 1000 Pa · sec or less, more preferably 0.5 to 500 Pa · sec, still more preferably 1 to 300 Pa · sec, The handling is preferably 3 to 200 Pa · sec.
If the solution viscosity exceeds 1000 Pa · sec, the fluidity is lost, so that uniform application to metal or glass becomes difficult, and if it is lower than 0.5 Pa · sec, it may sag during application to metal or glass. Since cissing and the like occur, it is not preferable, and it may be difficult to obtain an aromatic polyimide having high characteristics.

The polyimide precursor aqueous solution composition of the present invention can suitably obtain an aromatic polyimide by removing the water solvent by heat treatment and imidizing (dehydrating ring closure). The heat treatment conditions are not particularly limited, but are generally 100 ° C. or higher, preferably 120 ° C. to 600 ° C., more preferably 150 ° C. to 500 ° C., 0.01 hours to 30 hours, preferably 0.01 to 10 hours. is there.
The characteristic of the aromatic polyimide obtained using the polyimide precursor aqueous solution of the present invention is that a normal organic solvent is used only by heat treatment at a relatively low temperature (eg, 150 ° C. to 300 ° C., preferably 200 ° C. to 280 ° C.). Compared to the polyimide precursor (polyamic acid) solution composition used, it is possible to exhibit excellent characteristics such as high adhesiveness with, for example, metals.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples.

A method for measuring the characteristics used in the following examples is shown below.
<Concentration of solid content>
The sample solution (whose mass is designated as w1) is heat-treated in a hot air dryer at 120 ° C. for 10 minutes, 250 ° C. for 10 minutes, and then at 350 ° C. for 30 minutes. Measure). Solid content concentration [mass%] was computed by the following formula.
Solid content concentration [% by mass] = (w2 / w1) × 100

<Logarithmic viscosity>
The sample solution was diluted to a concentration of 0.5 g / dl (solvent is water) based on the solid content concentration. This diluted solution was added to Cannon Fenceke No. The flow-down time (T ₁ ) was measured using 100. The logarithmic viscosity was calculated from the following equation using the flow time (T ₀ ) of blank water.
Logarithmic viscosity = {ln (T ₁ / T ₀ )} / 0.5

<Solution viscosity (rotational viscosity)>
It measured at 30 degreeC using the Tokimec E-type viscosity meter.

<Preparation of polyimide film sample>
The obtained polyimide precursor aqueous solution composition was coated on a glass plate of a substrate by a bar coater, and the coating film was defoamed and pre-dried at 25 ° C. under reduced pressure for 30 minutes, and then heated under normal pressure under hot air. It put into the dryer and heat-processed at 80 degreeC for 30 minutes, 120 degreeC for 30 minutes, 200 degreeC for 10 minutes, and then 250 degreeC for 10 minutes, and formed the 50-micrometer-thick polyimide film. Properties were evaluated using this polyimide film.

<Mechanical properties (tensile test)>
Using a tensile tester (Orientec RTC-1225A), a tensile test was performed in accordance with ASTM D882 to determine the tensile modulus, tensile break elongation, and tensile break strength.

<Glass transition temperature measurement>
TA Instruments Co., Ltd. solid viscoelasticity analyzer RSAIII (compression mode dynamic measurement, frequency 62.8 rad / sec (10 Hz), strain amount set to 3% of sample height), −140 Measure from 30 ° C to 450 ° C at a temperature step of 3 ° C, measure 30 seconds after reaching each temperature, raise the temperature to the next temperature and repeat the measurement to obtain the maximum point of loss elastic modulus (E ''), The temperature was determined as the glass transition point (Tg).

The abbreviations of the compounds used in the following examples are described.
s-BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride ODPA: 4,4′-oxydiphthalic dianhydride PMDA: pyromellitic dianhydride a-BPDA: 2,3 ′ 3,4′-biphenyltetracarboxylic dianhydride i-BPDA: 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride DSDA: 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid Dianhydride BTDA: 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride PPD: p-phenylenediamine (solubility in water at 25 ° C .: 120 g / L, the same applies hereinafter)
ODA: 4,4′-diaminodiphenyl ether (0.19 g / L)
MPD: m-phenylenediamine (77 g / L)
2,4-TDA: 2,4-diaminotoluene (62 g / L)
HAB: 3,3′-dihydroxy-4,4′-diaminobiphenyl (1.3 g / L)
MBAA: bis (4-amino-3-carboxyphenyl) methane (200 g / L)
BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] propane (0.000019 g / L)
TPE-R: 1,3-bis (4-aminophenoxy) benzene (0.0018 g / L)
1,2-DMZ: 1,2-dimethylimidazole 2E4MZ: 2-ethyl-4-methylimidazole 2MZ: 2-methylimidazole DBU: 1,8-diazabicyclo [5,4,0] undec-7- En NMP: N-methyl-2-pyrrolidone

[Example 1]
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 1,2-DMZ were added thereto. Of 29.87 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 36.56 g (0.124 mol) of s-BPDA was added and stirred at 25 ° C. for 12 hours. The solid content concentration was 9.0% by mass, the solution viscosity was 16.3 Pa · s, and the logarithmic viscosity was 0.95. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

[Example 2]
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 1,2-DMZ were added thereto. Of 29.87 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 36.56 g (0.124 mol) of s-BPDA was added to this solution, and the mixture was stirred at 50 ° C. for 8 hours. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

Example 3
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 1,2-DMZ were added thereto. Of 29.87 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 36.56 g (0.124 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 9.1% by mass, the solution viscosity was 63.0 Pa · s, and the logarithmic viscosity was 1.86. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

Example 4
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 34.23 g of 2E4MZ were added thereto. (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 36.56 g (0.124 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours to obtain a solid content concentration of 9.6% by mass, a solution viscosity of 10.3 Pa · s, and a logarithmic viscosity of 0.64. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

Example 5
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 20.25 g (0.101 mol) of ODA and 1,2-DMZ were added thereto. Of 24.31 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 29.75 g (0.101 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 8.7% by mass, the solution viscosity was 32.0 Pa · s, and the logarithmic viscosity was 0.42. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

Example 6
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of MPD and 1,2-DMZ were added thereto. Of 29.87 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 36.56 g (0.124 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 8.9% by mass, the solution viscosity was 13.5 Pa · s, and the logarithmic viscosity was 0.75. An aqueous polyimide precursor solution was obtained.
The properties of the obtained polyimide precursor aqueous solution composition and polyimide film are shown in Table 1.

Example 7
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas introduction / discharge tube, and 14.67 g (0.120 mol) of 2,4-TDA was added thereto. , 2-DMZ (28.86 g (1.25 equivalents relative to carboxyl group)) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 35.33 g (0.120 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 8.8% by mass, the solution viscosity was 1.0 Pa · s, and the logarithmic viscosity was 0.21. An aqueous polyimide precursor solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 8
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet pipe, and 21.18 g (0.098 mol) of HAB was added to this and 1,2-DMZ. Was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 28.82 g (0.098 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 9.4% by mass, the solution viscosity was 1.5 Pa · s, and the logarithmic viscosity was 0.50. An aqueous polyimide precursor solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 9
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 24.66 g (0.086 mol) of MBAA and 1,2-DMZ were added thereto. Of 41.41 g (2.50 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 25.34 g (0.086 mol) of s-BPDA was added and stirred at 70 ° C. for 4 hours. The solid content concentration was 9.5% by mass, the solution viscosity was 2.0 Pa · s, and the logarithmic viscosity was 0.75. An aqueous polyimide precursor solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 10
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 12.93 g (0.120 mol) of PPD and 1,2-DMZ were added thereto. Of 28.73 g (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 37.07 g (0.120 mol) of ODPA was added and stirred at 70 ° C. for 4 hours to obtain a polyimide having a solid content concentration of 8.9% by mass, a solution viscosity of 2.0 Pa · s, and a logarithmic viscosity of 0.58. A precursor aqueous solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 11
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 1,2-DMZ were added thereto. Of 29.87 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 36.56 g (0.124 mol) of i-BPDA was added to this solution, and the mixture was stirred at 70 ° C. for 4 hours. The solid content concentration was 8.6% by mass, the solution viscosity was 0.8 Pa · s, and the logarithmic viscosity was 0.22. An aqueous polyimide precursor solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 12
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 11.59 g (0.107 mol) of PPD and 1,2-DMZ were added thereto. Of 25.77 g (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 38.41 g (0.107 mol) of DSDA was added and stirred at 70 ° C. for 4 hours to obtain a polyimide having a solid content concentration of 8.7% by mass, a solution viscosity of 1.2 Pa · s, and a logarithmic viscosity of 0.35. A precursor aqueous solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

Example 13
450 g of water was added as a solvent to a glass reaction vessel having an internal volume of 500 mL equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 12.57 g (0.116 mol) of PPD and 1,2-DMZ were added thereto. Of 27.93 g (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution was added 37.43 g (0.116 mol) of BTDA, and the mixture was stirred at 70 ° C. for 4 hours to obtain a water solution having a solid concentration of 8.8% by mass, a solution viscosity of 73.8 Pa · s, and a logarithmic viscosity of 0.45. A conductive polyimide precursor solution was obtained.
The characteristics of the obtained polyimide precursor aqueous solution composition are shown in Table 1.

[Comparative Example 1]
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 1,2-DMZ were added thereto. Of 17.92 g (0.75 equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 36.56 g (0.124 mol) of s-BPDA was added to this solution and stirred for 4 hours at 70 ° C., but it did not dissolve uniformly, and the polyimide precursor water solubility could not be obtained.
The results are shown in Table 2.

[Comparative Example 2]
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas introduction / discharge tube, and 13.44 g (0.124 mol) of PPD and 25.50 g of 2MZ were added thereto. (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 36.56 g (0.124 mol) of s-BPDA was added to this solution and stirred for 4 hours at 70 ° C., but it did not dissolve uniformly, and the polyimide precursor water solubility could not be obtained.
The results are shown in Table 2.

[Comparative Example 3]
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 13.44 g (0.124 mol) of PPD and 47.29 g of DBU were added thereto. (1.25 times equivalent to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 36.56 g (0.124 mol) of s-BPDA was added to this solution and stirred for 4 hours at 70 ° C., but it did not dissolve uniformly, and the polyimide precursor water solubility could not be obtained.
The results are shown in Table 2.

[Comparative Example 4]
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 29.13 g (0.071 mol) of BAPP and 1,2-DMZ were added thereto. Of 17.05 g (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 20.87 g (0.071 mol) of s-BPDA was added to this solution and stirred for 4 hours at 70 ° C., but it did not dissolve uniformly, and polyimide precursor water solubility could not be obtained.
The results are shown in Table 2.

[Comparative Example 5]
450 g of water was added as a solvent to a glass reaction vessel having an internal volume of 500 mL equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 24.92 g (0.085 mol) of TPE-R was added to the reaction vessel. -20.49 g of DMZ (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. 25.08 g (0.085 mol) of a-BPDA was added to this solution and stirred for 4 hours at 70 ° C., but it did not dissolve uniformly, and the polyimide precursor water solubility could not be obtained.
The results are shown in Table 2.

[Comparative Example 6]
450 g of water as a solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, and 23.93 g (0.120 mol) of ODA and 1,2-DMZ were added thereto. Of 28.73 g (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 26.07 g (0.120 mol) of PMDA was added and stirred at 70 ° C. for 4 hours. However, the solution was not uniformly dissolved, and water solubility of the polyimide precursor could not be obtained.
The results are shown in Table 2.

[Comparative Example 7]
To a 500 mL glass reaction vessel equipped with a stirrer and a nitrogen gas inlet / outlet tube, 450 g of water was added as a solvent, and 24.26 g (0.083 mol) of TPE-R and 2E4MZ 22 .86 g (1.25 equivalents relative to the carboxyl group) was added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 25.74 g (0.083 mol) of ODPA was added and stirred at 70 ° C. for 4 hours. However, the solution was not uniformly dissolved, and water solubility of the polyimide precursor could not be obtained.
The results are shown in Table 2.

[Comparative Example 8]
450 g of water was added as a solvent to a 500 mL glass reaction vessel equipped with a stirrer and nitrogen gas inlet / outlet tube, and 8.94 g (0.083 mol) of PPD and 11.03 g of ODA were added thereto. (0.055 mol) and 33.10 g of 1,2-DMZ (1.25 equivalents relative to the carboxyl group) were added and stirred at 25 ° C. for 1 hour to dissolve. To this solution, 30.03 g (0.138 mol) of PMDA was added and stirred at 70 ° C. for 4 hours. However, the solution was not uniformly dissolved, and water solubility of the polyimide precursor could not be obtained.
The results are shown in Table 2.

[Reference Example 1]
29.23 g (0.1 mol) of TPE-R and 234.60 g of DMAc were placed in a 1000 mL glass reaction vessel equipped with a stirrer, a reflux condenser (with a water separator), a thermometer, and a nitrogen introduction tube. The mixture was added at 25 ° C., and 29.42 g (0.1 mol) of a-BPDA was added to the mixed solution while stirring under a nitrogen gas flow, and reacted for 2 hours to obtain a polyimide precursor solution. This solution was then diluted with 293.25 g of DMAc to 1.3 poise at 30 ° C. To this solution, 5.87 g (0.06 mol) of DMZ was added, and this solution was gradually added to acetone (6.5 L) equipped with a homogenizer to precipitate a polyimide precursor powder. This suspension was filtered, washed with acetone, and vacuum-dried at 40 ° C. for 10 hours to obtain 60.52 g of polyimide precursor powder.

  To 3 g of this polyimide precursor powder, 26.10 g of water and 0.9 g (0.0094 mol) of 1,2-DMZ were added and dissolved in 2 hours while stirring at 60 ° C. to obtain a uniform polyimide precursor An aqueous solution was obtained. When this aqueous solution was analyzed for generated gas using GC-MS, 6.28% of DMAc was detected, and the remaining organic solvent was confirmed.

  According to the present invention, the environmental adaptability is good by using an aqueous solvent, and the aromatic polyimide obtained by using the water solvent has high crystallinity, so that it has heat resistance, mechanical strength, electrical properties, resistance to resistance. It is possible to provide a polyimide precursor aqueous solution composition having excellent solvent properties and the like, preferably having a high molecular weight and containing no organic solvent other than water.

Claims (7)

A polyamic acid comprising a repeating unit represented by the following chemical formula (1) obtained by reacting a tetracarboxylic acid component and a diamine component is 1.6 times mol or more with respect to the tetracarboxylic acid component of the polyamic acid. A polyimide precursor aqueous solution composition dissolved in an aqueous solvent together with imidazoles having two or more alkyl groups as substituents.

In the chemical formula (1), A is a tetravalent group obtained by removing a carboxyl group from a tetracarboxylic acid having 2 to 3 aromatic rings, and B is an aromatic having 1 to 2 aromatic rings. A divalent group obtained by removing an amino group from a diamine, and the solubility of the aromatic diamine in water at 25 ° C. is 0.1 g / L or more.   Imidazoles having two or more alkyl groups as substituents are from 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, and 1-methyl-4-ethylimidazole. The polyimide precursor aqueous solution composition according to claim 1, wherein the composition is an imidazole selected from the group consisting of: The polyimide precursor aqueous solution composition according to claim 1 or 2, wherein A in the chemical formula (1) is the following chemical formulas (2) to (7) or a mixture thereof.

The polyimide precursor aqueous solution composition according to claim 1, wherein B in the chemical formula (1) is the following chemical formulas (8) to (9) or a mixture thereof.

  The polyimide precursor aqueous solution composition according to claim 1, wherein the logarithmic viscosity is 0.2 or more.   Content of an organic solvent is less than 5%, The polyimide precursor aqueous solution composition in any one of Claims 1-5 characterized by the above-mentioned.   The aqueous solution of polyimide precursor according to claim 1, wherein the aqueous solvent does not substantially contain an organic solvent other than water.