JP5846285B2 - Polyimide precursor composition - Google Patents

Description

  The present invention relates to a polyimide precursor composition.

A polyimide resin is a material having high durability and excellent heat resistance, and is widely used for electronic materials.
As a method for producing a molded article of polyimide resin, a polyimide precursor composition obtained by dissolving a precursor polyamic acid in an aprotic polar solvent such as N-methyl-2-pyrrolidone (NMP) is formed on a substrate. A method for producing a polyimide molded body by applying, drying and imidizing by heat treatment is known (for example, see Patent Document 1).

  Also, in the production of polyimide precursor compositions, the polyimide precursor resin is polymerized in an aprotic polar solvent such as NMP, the polyimide precursor resin is taken out by reprecipitation method, and then dissolved in water by the action of an amine salt. It is also known to go through a process (see, for example, Patent Documents 2 to 5).

  Examples of the solvent for dissolving polyamic acid include NMP, dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DMSO), and γ-butyrolactone (γ-BL) (for example, non-patent literature). 1).

  On the other hand, as an aprotic polar solvent, a water-soluble alcohol solvent compound and / or a water-soluble ether solvent compound is used. Specifically, in a mixed solvent of tetrahydrofuran (THF) and methanol, or THF and water. It is known that a polyimide precursor composition is obtained without precipitation by adding a tertiary amine to a reaction system in a mixed solvent (see, for example, Patent Document 6).

  It is also known to obtain a water-based polyimide precursor composition by polymerizing a polyimide precursor in water in the presence of imidazole having a specific structure as an amine compound (see, for example, Patent Document 7).

U.S. Pat. No. 4,238,528 Japanese Patent Laid-Open No. 08-120077 Japanese Patent Laid-Open No. 08-015519 JP 2003-13351 A JP 08-059832 A JP 08-157599 A JP 2012-036382 A

Journal of Polymer Science. Macromolecular Reviews, Vol.11, P164 (1976)

  The subject of this invention is providing the polyimide precursor composition from which the polyimide molded body with high mechanical strength is obtained.

  In order to achieve the above object, the following invention is provided.

The invention according to claim 1
One or more organic solvents selected from a water-soluble alcohol solvent, a water-soluble ether solvent, and a water-soluble ketone solvent, and a solvent containing water, a repeating unit represented by the following general formula (I) And an imidation ratio of 0.2 or less and an organic amine compound of 50 mol% or more and 500 mol% or less with respect to the carboxyl group contained in the resin are dissolved. The polyimide precursor has a boiling point of 40 ° C. or more and 160 ° C. or less, does not contain an aprotic polar solvent, and contains the water in an amount of 30% by mass to 99.9% by mass with respect to the total solvent. Body composition.

(In general formula (I), A represents a tetravalent organic group, and B represents a divalent organic group.)

The invention according to claim 2
2. The polyimide precursor composition according to claim 1 , wherein, in the general formula (I), A represents a tetravalent aromatic organic group and B represents a divalent aromatic organic group.

The invention according to claim 3
The polyimide precursor composition according to claim 1 or 2 , wherein the organic amine compound is at least one selected from a secondary amine compound and a tertiary amine compound.

The invention according to claim 4
The polyimide precursor composition according to any one of claims 1 to 3 , wherein the resin includes a resin having an amino group at a terminal.

The invention according to claim 5
The polyimide precursor composition according to any one of claims 1 to 4 , wherein the resin has a number average molecular weight of 1,000 or more and 100,000 or less.

According to the inventions according to claims 1 and 2 , a polyimide precursor composition capable of obtaining a polyimide molded body having high mechanical strength as compared with a case where an aprotic polar solvent such as N-methyl-2-pyrrolidone (NMP) is contained. Things are provided.
According to the invention which concerns on Claim 1 , compared with the case where the boiling point of an organic solvent exceeds 160 degreeC, the polyimide precursor composition from which a polyimide molded body with high mechanical strength is obtained is provided.

According to the invention which concerns on Claim 1 , compared with the case where content of water is outside the said range, the polyimide precursor composition excellent in film forming property is provided.

According to the invention which concerns on Claim 1, compared with the case where content of an organic amine compound is outside the said range, the polyimide precursor composition excellent in film forming property is provided.
According to the invention which concerns on Claim 3 , compared with the case where an organic amine compound is a primary amine compound, the polyimide precursor composition excellent in film forming property is provided.

According to the invention which concerns on Claim 4 , compared with the case where it has a carboxyl group in all the terminals of resin, the polyimide precursor composition excellent in film forming property is provided.
According to the invention which concerns on Claim 5 , compared with the case where the number average molecular weight of resin is outside the said range, the polyimide precursor composition excellent in film forming property is provided.

  Hereinafter, embodiments of the present invention will be described in detail.

<Polyimide precursor composition>
The polyimide precursor composition according to this embodiment has a resin having a repeating unit represented by the general formula (I) and an imidization ratio of 0.2 or less (hereinafter referred to as “specific polyimide precursor”). And an organic amine compound are dissolved. That is, the specific polyimide precursor and the organic amine compound are contained in the composition in a state dissolved in a solvent. In addition, melt | dissolution shows the state which the residue of melt | dissolution does not confirm visually.
The solvent includes one or more organic solvents (hereinafter referred to as “specific organic solvents”) selected from water-soluble ether solvents, water-soluble ketone solvents, and water-soluble alcohol solvents, and water. Solvent is applied.
However, an organic solvent having a boiling point of 40 ° C. or higher and 160 ° C. or lower is applied as the organic solvent to the polyimide precursor composition according to the present embodiment. Moreover, content of an organic amine compound shall be 50 mol% or more and 500 mol% or less with respect to the carboxyl group contained in resin. Moreover, water is contained at 30% by mass or more and 99.9% by mass or less with respect to the total solvent.

Here, the polyimide precursor composition according to this embodiment is a composition that does not contain an aprotic polar solvent.
The aprotic polar solvent is a solvent having a boiling point of 150 ° C. or higher and 300 ° C. or lower and a dipole moment of 3.0D or higher and 5.0D or lower. Specific examples of the aprotic polar solvent include N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), Hexamethylene phosphoramide (HMPA), N-methylcaprolactam, N-acetyl-2-pyrrolidone and the like can be mentioned.

  The aprotic polar solvent represented by N-methyl-2-pyrrolidone (NMP) has a high boiling point of 150 ° C. or higher, and the solvent in the composition remains in the molded body even after the drying step in the production of the polyimide molded body. Often remains. If this aprotic polar solvent remains in the polyimide molded body, it causes reorientation of the polymer chain of the polyimide precursor and impairs the packing properties of the polymer chain, resulting in a decrease in the mechanical strength of the resulting polyimide molded body. May cause.

On the other hand, in the polyimide precursor composition according to the present embodiment, a solvent containing a specific organic solvent and water is not applied as a solvent, but an aprotic polar solvent is used. Does not contain aprotic polar solvents.
The specific polyimide precursor as a polyimide precursor is not a low-molecular compound, and it can be dissolved in a solvent by lowering the interaction force between polymer chains by introducing a bent chain or an aliphatic cyclic structure into the primary structure. A specific organic solvent and a solvent containing water are used as a solvent, not a structure with enhanced properties, and the specific polyimide precursor (its carboxyl group) is dissolved in an amine-chlorinated state with an organic amine compound. For this reason, the fall of the mechanical strength of the polyimide molded body which arises by making a polyimide precursor low molecular weight or changing a structure is suppressed.

For this reason, the polyimide precursor composition which concerns on this embodiment is considered that the polyimide resin molding with high mechanical strength is obtained by the said composition.
In addition to the mechanical strength, the polyimide precursor composition according to the present embodiment is easy to obtain a polyimide resin molded article excellent in various properties such as heat resistance, electrical properties, and solvent resistance.

Moreover, the polyimide precursor composition which concerns on this embodiment applied the mixed solvent containing a specific organic solvent and water as a solvent, and the specific polyimide precursor (its carboxyl group) was amine-chlorinated by the organic amine compound to this. Since it is dissolved in a state, it has high film-forming properties and excellent environmental suitability.
In addition, when a mixed solvent containing a specific organic solvent and water is applied as a solvent, when molding a polyimide molded body using a polyimide precursor composition, the heating temperature for solvent distillation is reduced and the heating time is shortened. Is realized.
Moreover, since the organic amine compound is dissolved in the solvent in the state of being amine-chlorinated in the specific polyimide precursor (its carboxyl group), the odor peculiar to the amine compound can be suppressed.

  In particular, in general formula (I), a specific polyimide precursor (that is, an aromatic polyimide precursor) in which A represents a tetravalent aromatic organic group and B represents a divalent aromatic organic group is applied. In this case, although it tends to be difficult to dissolve in a solvent, a solvent containing a specific organic solvent and water is applied as a solvent, and the specific polyimide precursor is dissolved in an amine-chlorinated state with an organic amine compound. For this reason, even if it is a case where an aromatic polyimide precursor is applied as a specific polyimide precursor, film forming property is high and it is excellent in environmental suitability.

  Hereinafter, each component of the polyimide precursor composition according to the present embodiment will be described.

(Specific polyimide precursor)
The specific polyimide precursor is a resin (polyamic acid) having a repeating unit represented by the general formula (I) and having an imidization ratio of 0.2 or less.

  In general formula (I), A represents a tetravalent organic group, and B represents a divalent organic group.

Here, in the general formula (I), the tetravalent organic group represented by A is a residue obtained by removing four carboxyl groups from a tetracarboxylic dianhydride as a raw material.
On the other hand, the divalent organic group represented by B is a residue obtained by removing two amino groups from a diamine compound as a raw material.

  That is, the specific polyimide precursor having a repeating unit represented by the general formula (I) is a polymer of tetracarboxylic dianhydride and a diamine compound.

  Examples of tetracarboxylic dianhydrides include aromatic and aliphatic compounds, and aromatic compounds are preferred. That is, in the general formula (I), the tetravalent organic group represented by A is preferably an aromatic organic group.

  Examples of the aromatic tetracarboxylic acid include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic acid. Acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetra Carboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1,2, 3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) Diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3, 3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene- Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) ) -4,4′-diphenylmethane dianhydride and the like.

  Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4. -Cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2- Acetic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride , Aliphatic or alicyclic tetracarboxylic dianhydrides such as bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride; 3a, 4,5,9b-Hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro Aliphatic tetracarboxylic dianhydrides having an aromatic ring such as -8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione Etc.

  Among these, the tetracarboxylic dianhydride is preferably an aromatic tetracarboxylic dianhydride, specifically, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyl. Tetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4 4'-benzophenone tetracarboxylic dianhydride is preferable, and pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'- Benzophenone tetracarboxylic dianhydride is preferable, and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride is particularly preferable.

  In addition, tetracarboxylic dianhydride may be used individually by 1 type, and may be used together in combination of 2 or more type. Moreover, when using together and using 2 or more types, you may use together aromatic tetracarboxylic acid or aliphatic tetracarboxylic acid, respectively, or may combine aromatic tetracarboxylic acid and aliphatic tetracarboxylic acid.

  On the other hand, a diamine compound is a diamine compound having two amino groups in the molecular structure. Examples of the diamine compound include aromatic compounds and aliphatic compounds, and aromatic compounds are preferable. That is, in the general formula (I), the divalent organic group represented by B is preferably an aromatic organic group.

Examples of the diamine compound include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide. 4,4′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3 -Trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 4,4'-diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide 3,5-diamino-4′-trifluoromethylbenzanilide, 3,4′-diaminodiphenyl ether, , 7-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4 , 4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino -2,2'-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoro Propane, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) -biphenyl, 1,3′-bis (4-aminophenoxy) benzene, 9,9-bi (4-aminophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino- 2-trifluoromethylphenoxy) phenyl] hexafluoropropane, aromatic diamines such as 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; and diaminotetraphenylthiophene An aromatic diamine having two amino groups bonded to an aromatic ring such as a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine , Pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diamy Heptamethylene diamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene cyclopentadienylide diamine, hexahydro-4,7-meth Noin mite range diamine, tricyclo [6,2,1,0 ^2.7] Examples thereof include aliphatic diamines such as undecylenedimethyl diamine and 4,4′-methylene bis (cyclohexylamine), and alicyclic diamines.

  Among these, as the diamine compound, an aromatic diamine compound is good, and specifically, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, and 4,4′-diaminodiphenyl sulfone are preferable, and 4,4′-diaminodiphenyl ether and p-phenylenediamine are particularly preferable.

  In addition, a diamine compound may be used individually by 1 type, and may be used together in combination of 2 or more type. Moreover, when using together and using 2 or more types, you may use together an aromatic diamine compound or an aliphatic diamine compound, respectively, or may combine an aromatic diamine compound and an aliphatic diamine compound.

The specific polyimide precursor is a resin having an imidization rate of 0.2 or less. That is, the specific polyimide precursor may be a resin partially imidized.
Specifically, examples of the specific polyimide precursor include a resin having a repeating unit represented by General Formula (I-1), General Formula (I-2), and General Formula (I-3).

In General Formula (I-1), General Formula (I-2), and General Formula (I-3), A represents a tetravalent organic group, and B represents a divalent organic group. In addition, A and B are synonymous with A and B in general formula (I).
l represents an integer of 1 or more, m and n each independently represents 0 or an integer of 1 or more, and satisfies the relationship of (2n + m) / (2l + 2m + 2n) ≦ 0.2.

In general formulas (I-1) to (I-3), l represents an integer of 1 or more, preferably an integer of 1 to 200, more preferably an integer of 1 to 100. m and n each independently represent an integer of 0 or 1 or more, but preferably each independently represents an integer of 0 or 1 to 200, more preferably 0 or an integer of 1 to 100.
L, m, and n satisfy the relationship (2n + m) / (2l + 2m + 2n) ≦ 0.2, but preferably (2n + m) / (2l + 2m + 2n) ≦ 0.15, more preferably (2n + m) / ( 2l + 2m + 2n) ≦ 0.10.

In General Formula (I-1), General Formula (I-2), and General Formula (I-3), A represents a tetravalent organic group, and B represents a divalent organic group. In addition, A and B are synonymous with A and B in general formula (I).
l, m, and n each independently represent an integer of 0 or 1 and satisfy the relationship of (2n + m) / (2l + 2m + 2n) ≦ 0.2. However, at least one of l and m represents an integer of 1 or more.

In the general formulas (I-1) to (I-3), l, m and n each independently represent an integer of 0 or 1 or more, preferably each independently of 0 or an integer of 1 or more and 200 or less. Desirably, 0 or an integer of 1 to 100 is preferably shown.
L, m, and n satisfy the relationship (2n + m) / (2l + 2m + 2n) ≦ 0.2, but preferably (2n + m) / (2l + 2m + 2n) ≦ 0.15, more preferably (2n + m) / ( 2l + 2m + 2n) ≦ 0.10.
However, at least one of l and m represents an integer of 1 or more.

Here, “(2n + m) / (2l + 2m + 2n)” is the total number of bonding parts (2n + m) in which the imide ring is closed in the bonding part of the specific polyimide precursor (reaction part of tetracarboxylic dianhydride and diamine compound). The ratio to the number of coupled parts (2l + 2m + 2n) is shown. That is, “(2n + m) / (2l + 2m + 2n)” represents the imidization ratio of the specific polyimide precursor.
The specific polyimide precursor has an imidization ratio (value of “(2n + m) / (2l + 2m + 2n)”) of 0.2 or less (preferably 0.15 or less, more preferably 0.10). Inducing the gelation and precipitation separation of the precursor is suppressed.

  The imidation ratio (value of “(2n + m) / (2l + 2m + 2n)”) of the specific polyimide precursor is measured by the following method.

-Measurement of imidization rate of polyimide precursor-
-Preparation of polyimide precursor sample (i) A polyimide precursor composition to be measured is applied on a silicone wafer in a film thickness range of 1 µm to 10 µm to prepare a coating film sample.
(Ii) The coating film sample is immersed in tetrahydrofuran (THF) for 20 minutes to replace the solvent in the coating film sample with tetrahydrofuran (THF). The solvent to be immersed is not limited to THF, and can be selected from solvents that do not dissolve the polyimide precursor and are miscible with the solvent component contained in the polyimide precursor composition. Specifically, alcohol solvents such as methanol and ethanol, and ether compounds such as dioxane can be used.
The (iii) coating samples, taken out from in THF, blowing _{N 2} gas into THF adhering to the coating surface of the sample, removed. Under a reduced pressure of 10 mmHg or less, the coating film sample is dried for 12 hours or more in the range of 5 ° C. or more and 25 ° C. or less to prepare a polyimide precursor sample.

-Preparation of 100% imidized standard sample (iv) Similarly to the above (i), a polyimide precursor composition to be measured is applied on a silicone wafer to prepare a coating film sample.
(V) The coating film sample is heated at 380 ° C. for 60 minutes to carry out an imidization reaction to produce a 100% imidized standard sample.

Measurement and analysis (vi) Using a Fourier transform infrared spectrophotometer (FT-730, manufactured by Horiba, Ltd.), the infrared absorption spectrum of a 100% imidized standard sample and a polyimide precursor sample is measured. Aromatic ring-derived absorption peak near 1500 cm ^-1 and 100% imidization standard sample (Ab ratio 'for (1500cm ^-1)), absorption peaks derived from an imide bond in the vicinity of ^{1780cm -1 (Ab' (1780cm -1} )) I '(100) is obtained.
(Vii) In the same manner, was measured on the polyimide precursor sample, relative to the aromatic ring derived absorption peak near ^{1500cm -1 (Ab (1500cm -1)} ), absorption peaks derived from imide bond near 1780 cm ^-1 (Ab ( 1780 cm ⁻¹ )) ratio I (x) is determined.

And the imidation rate of a polyimide precursor is computed based on the following formula using each measured absorption peak I '(100) and I (x).
Formula: Imidation ratio of polyimide precursor = I (x) / I ′ (100)
Formula: I ′ (100) = (Ab ′ (1780 cm ⁻¹ )) / (Ab ′ (1500 cm ⁻¹ ))
Formula: I (x) = (Ab (1780 cm ⁻¹ )) / (Ab (1500 cm ⁻¹ ))

  In addition, the measurement of the imidation rate of this polyimide precursor is applied to the measurement of the imidation rate of an aromatic polyimide precursor. When measuring the imidation ratio of the aliphatic polyimide precursor, a peak derived from a structure having no change before and after the imidation reaction is used as an internal standard peak instead of the absorption peak of the aromatic ring.

-Terminal amino group of polyimide precursor-
The specific polyimide precursor may include a polyimide precursor (resin) having an amino group at a terminal, and preferably a polyimide precursor having an amino group at all terminals.
In order to have amino groups at both molecular ends of the polyimide precursor, for example, the molar equivalent of the diamine compound used in the polymerization reaction is added in excess of the molar equivalent of tetracarboxylic dianhydride. The The molar equivalent ratio between the diamine compound and the tetracarboxylic dianhydride is preferably in the range of 1.0001 or more and 1.2 or less, more preferably 1 in terms of the molar equivalent of the tetracarboxylic acid. The range is from 0.001 to 1.2.
If the molar equivalent ratio of the diamine compound to tetracarboxylic dianhydride is 1.0001 or more, the effect of the amino group at the molecular end is great, and good dispersibility is obtained. If the molar equivalent ratio is 1.2 or less, the molecular weight of the obtained polyimide precursor is large. For example, when a film-like polyimide molded body is obtained, sufficient film strength (tear strength, tensile strength) is obtained. It is easy to obtain.

  The terminal amino group of a specific polyimide precursor is detected by making trifluoroacetic anhydride (react quantitatively with respect to an amino group) act on a polyimide precursor composition. That is, the terminal amino group of the specific polyimide precursor is amidated with trifluoroacetic acid. After the treatment, the specific polyimide precursor is purified by reprecipitation or the like to remove excess trifluoroacetic anhydride and trifluoroacetic acid residue. About the specific polyimide precursor after a process, the amount of terminal amino groups of a specific polyimide precursor is measured by quantifying with a nuclear magnetic resonance (NMR) method.

The number average molecular weight of the specific polyimide precursor is preferably from 1,000 to 100,000, preferably from 5,000 to 50,000, and more preferably from 10,000 to 30,000.
When the number average molecular weight of the specific polyimide precursor is within the above range, a decrease in the solubility of the specific polyimide precursor in the solvent is suppressed, and film forming properties are easily secured. In particular, when a specific polyimide precursor having an amino group at the terminal is applied, if the molecular weight is low, the abundance of the terminal amino group is increased and the solubility is affected by the coexisting organic amine compound in the polyimide precursor composition. Although it is easy to fall, the fall of solubility can be suppressed by making the range of the number average molecular weight of a specific polyimide precursor into the said range.
In addition, the specific polyimide precursor of the target number average molecular weight is obtained by adjusting the molar equivalent ratio of a tetracarboxylic dianhydride and a diamine compound.

The number average molecular weight of the specific polyimide precursor is measured by gel permeation chromatography (GPC) method under the following measurement conditions.
Column: Tosoh TSKgel α-M (7.8 mm ID × 30 cm)
Eluent: DMF (dimethylformamide) / 30 mM LiBr / 60 mM phosphoric acidFlow rate: 0.6 mL / min
・ Injection volume: 60 μL
・ Detector: RI (differential refractive index detector)

  The content (concentration) of the specific polyimide precursor is preferably 0.1% by mass or more and 40% by mass or less, and preferably 0.5% by mass or more and 25% by mass or less, based on the total polyimide precursor composition. More desirably, it is 1% by weight or more and 20% by weight or less.

(Organic amine compound)
An organic amine compound is a compound that functions as an imidization accelerator while amine-chlorinating a specific polyimide precursor (its carboxyl group) to increase its solubility in a solvent.
The organic amine compound is preferably a water-soluble compound. Here, water-soluble means that the target substance dissolves 1% by mass or more in water at 25 ° C.

Examples of organic amine compounds include primary amine compounds, secondary amine compounds, and tertiary amine compounds.
Among these, as the organic amine compound, at least one selected from a secondary amine compound and a tertiary amine compound (particularly a tertiary amine compound) is preferable. When a tertiary amine compound or a secondary amine compound is applied as the organic amine compound, the solubility of the specific polyimide precursor in the solvent is likely to be increased, the film forming property is easily improved, and the solution of the polyimide precursor composition Stability is easily improved.

  Moreover, as an organic amine compound, the polyvalent amine compound more than bivalence other than a monovalent amine compound is also mentioned. When a polyvalent amine compound having two or more valences is applied, a pseudo-crosslinked structure is easily formed between molecules of the specific polyimide precursor, and the solution stability of the polyimide precursor composition is easily improved.

Examples of the primary amine compound include methylamine, ethylamine, n-propylamine, isopropylamine, 2-ethanolamine, 2-amino-2-methyl-1-propanol, and the like.
Examples of the secondary amine compound include dimethylamine, 2- (methylamino) ethanol, 2- (ethylamino) ethanol, morpholine, and the like.
Examples of the tertiary amine compound include 2-dimethylaminoethanol, 2-diethylaminoethanol, 2-dimethylaminopropanol, pyridine, triethylamine, picoline, methylmorpholine, ethylmorpholine, and the like.

  Examples of the polyvalent amine compound include isoquinolines, pyrimidines, pyrazines, piperazines, triazines, polyaniline, polypyridine, polyamine and the like.

  Among these, the organic amine compound is preferably a compound having a boiling point of 60 ° C. or higher (desirably 60 ° C. or higher and 200 ° C. or lower, more preferably 70 ° C. or higher and 150 ° C. or lower). When the boiling point of the organic amine compound is 60 ° C. or higher, the organic amine compound is prevented from volatilizing from the polyimide precursor composition during storage, and the decrease in the solubility of the specific polyimide precursor in the solvent is easily suppressed.

The organic amine compound may be contained in an amount of 50 mol% to 500 mol%, preferably 80 mol% to 250 mol%, more preferably 100 mol, based on the carboxyl group contained in the specific polyimide precursor. % Or more and 200 mol% or less.
When the content of the organic amine compound is within the above range, the solubility of the specific polyimide precursor in the solvent is likely to increase, and the film forming property is easily improved. Moreover, it becomes easy to improve the solution stability of a polyimide precursor composition.

(solvent)
As the solvent, a mixed solvent of a specific organic solvent and water is applied. The specific organic solvent is one or more organic solvents selected from water-soluble ether solvents, water-soluble ketone solvents, and water-soluble alcohol solvents. Here, water-soluble means that the target substance dissolves 1% by mass or more in water at 25 ° C.

As a combination of the mixed solvent, for example, a combination of a water-soluble ether solvent and water, or a combination of a water-soluble ketone solvent and water is preferable.
Further, the specific organic solvent may be used alone, but when two or more kinds are used in combination, for example, a combination of a water-soluble ether solvent and a water-soluble alcohol solvent, a water-soluble ketone solvent and a water-soluble alcohol Examples thereof include a combination with a solvent, and a combination of a water-soluble ether solvent, a water-soluble ketone solvent, and a water-soluble alcohol solvent.

  The water-soluble ether solvent is a water-soluble solvent having an ether bond in one molecule. Examples of the water-soluble ether solvent include tetrahydrofuran (THF), dioxane, trioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and the like. Among these, tetrahydrofuran and dioxane are desirable as the water-soluble ether solvent.

  The water-soluble ketone solvent is a water-soluble solvent having a ketone group in one molecule. Examples of the water-soluble ketone solvent include acetone, methyl ethyl ketone, and cyclohexanone. Among these, acetone is desirable as the water-soluble ketone solvent.

  The water-soluble alcohol solvent is a water-soluble solvent having an alcoholic hydroxyl group in one molecule. Examples of the water-soluble alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, tert-butyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, glycerin, 2-ethyl-2- Examples include hydroxymethyl-1,3-propanediol and 1,2,6-hexanetriol. Among these, methanol, ethanol, 2-propanol, and ethylene glycol are desirable as the water-soluble alcohol solvent.

  The specific organic solvent preferably has a boiling point of 160 ° C. or lower, desirably 40 ° C. or higher and 150 ° C. or lower, more desirably 50 ° C. or higher and 120 ° C. or lower. When the boiling point of the specific organic solvent is in the above range, the specific organic solvent hardly remains in the polyimide molded body, and a polyimide molded body with high mechanical strength is easily obtained.

  On the other hand, examples of water include distilled water, ion exchange water, ultrafiltration water, and pure water.

Water is preferably contained in an amount of 30% by mass to 99.9% by mass with respect to the total solvent, desirably 50% by mass to 99.9% by mass, and more desirably 80% by mass to 99.9% by mass. It is to contain. In addition, a specific organic solvent is contained in a solvent as the remainder except water of all the solvents.
When the water content is within the above range, the solubility of the amine-cured specific polyimide precursor in the solvent increases and the film-forming property is improved.

  Here, the range in which the specific polyimide precursor is dissolved in the solvent is controlled by the water content and the type / amount of the organic amine compound. In a range where the water content is low, the specific polyimide precursor is easily dissolved in a region where the addition amount of the organic amine compound is small. On the other hand, in a range where the water content is high, the specific polyimide precursor is easily dissolved in a region where the amount of the organic amine compound added is large. In addition, when the organic amine compound includes a hydroxyl group and has high hydrophilicity, the specific polyimide precursor is easily dissolved in a region having a high water content.

(Other additives)
The polyimide precursor composition according to the present embodiment may contain various fillers for the purpose of imparting various functions such as conductivity and mechanical strength to a polyimide molded body produced using the polyimide precursor composition. In addition, a catalyst for promoting imidization reaction, a leveling material for improving film forming quality, and the like may be included.

Examples of the conductive material added to impart conductivity include conductivity (for example, volume resistivity of less than 10 ⁷ Ω · cm, the same shall apply hereinafter) or semi-conductivity (for example, volume resistivity of 10 ⁷ Ω · cm to 10 ¹³ Ω). -Cm or less, the same applies hereinafter), and is selected according to the purpose of use.
Examples of the conductive agent include carbon black (for example, acidic carbon black having a pH of 5.0 or less), metal (for example, aluminum or nickel), metal oxide (for example, yttrium oxide, tin oxide, etc.), ion conductive material (for example, titanium). Potassium oxide, LiCl, etc.), conductive polymers (eg, polyaniline, polypyrrole, polysulfone, polyacetylene, etc.).
These conductive materials may be used alone or in combination of two or more.
In the case where the conductive material is in the form of particles, the primary particle size is less than 10 μm, preferably 1 μm or less.

  Examples of the filler added for improving the mechanical strength include particulate materials such as silica powder, alumina powder, barium sulfate powder, titanium oxide powder, mica and talc. In addition, in order to improve the water repellency and releasability of the surface of the polyimide molded body, a fluororesin powder such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) is added. Also good.

  As the catalyst for promoting the imidization reaction, a dehydrating agent such as an acid anhydride, an acid catalyst such as a phenol derivative, a sulfonic acid derivative, or a benzoic acid derivative may be used.

  A surfactant may be added to improve the film forming quality of the polyimide molded body. As the surfactant to be used, any of cationic, anionic and nonionic surfactants may be used.

  What is necessary is just to select content of another additive according to the intended purpose of the polyimide molded body to manufacture.

<Method for producing polyimide precursor composition>
The method for producing a polyimide precursor composition according to the present embodiment includes at least one organic solvent selected from a water-soluble ether solvent, a water-soluble ketone solvent, and a water-soluble alcohol solvent (hereinafter referred to as “specific organic solvent”). And a step of polymerizing a tetracarboxylic dianhydride and a diamine compound in a solvent containing water to produce a resin (hereinafter referred to as “polyimide precursor”) (hereinafter referred to as “polymerization step”). And a step of adding an organic amine compound to the solvent after forming the resin (hereinafter referred to as “amine chlorination step”). Moreover, you may have the process (henceforth a "solvent replacement process") which substitutes a solvent or changes a solvent composition after a polymerization process as needed.

  In the method for producing a polyimide precursor composition according to the present embodiment, an aprotic polar solvent is not included, a polyimide precursor is produced in a solvent containing a specific organic solvent and water, and an organic amine compound is then added to the solvent. Addition and amine chloride of the polyimide precursor (its carboxyl group).

  The method for producing a polyimide precursor composition according to this embodiment does not use an aprotic polar solvent that causes a decrease in mechanical strength of the polyimide molded body as a solvent. In addition, since the organic amine compound is added after the polyimide precursor is generated (the organic amine compound is not added in the polymerization step), the organic amine compound suppresses the formation inhibition of the polyimide precursor (inhibition of the polymerization reaction).

For this reason, in the manufacturing method of the polyimide precursor composition which concerns on this embodiment, the polyimide precursor composition from which the polyimide molded body with high mechanical strength is obtained is manufactured.
In addition, in the method for producing a polyimide precursor composition according to this embodiment, a polyimide precursor composition in which a polyimide molded body excellent in various properties such as heat resistance, electrical properties, and solvent resistance in addition to mechanical strength is easily obtained. Things are manufactured.

  Moreover, in the manufacturing method of the polyimide precursor composition which concerns on this embodiment, since the mixed solvent containing a specific organic solvent and water is applied as a solvent, productivity is also high and a polyimide precursor composition is manufactured. . In particular, when solvent replacement is performed, excessive heating is not necessary, and thermal imidization of the generated polyimide precursor is easily suppressed.

  Hereinafter, each process of the manufacturing method of the polyimide precursor composition which concerns on this embodiment is demonstrated. In addition, since each material used is the same as that of what was demonstrated with the polyimide precursor composition which concerns on the said this embodiment, description is abbreviate | omitted.

(Polymerization process)
In the polymerization step, a tetracarboxylic dianhydride and a diamine compound are polymerized in a solvent containing a specific organic solvent and water to produce a polyimide precursor.

The reaction temperature during the polymerization reaction of the polyimide precursor is, for example, preferably from 0 ° C. to 70 ° C., preferably from 10 ° C. to 60 ° C., more preferably from 20 ° C. to 55 ° C. By setting the reaction temperature to 0 ° C. or higher, the reaction heat generated by the polymerization reaction is removed to promote the progress of the polymerization reaction, the time required for the reaction is shortened, and the productivity is easily improved. On the other hand, when the reaction temperature is 70 ° C. or lower, the progress of the imidization reaction occurring in the molecule of the generated polyimide precursor is suppressed, and precipitation or gelation associated with a decrease in solubility of the polyimide precursor is easily suppressed.
The time during the polymerization reaction of the polyimide precursor is preferably in the range of 1 hour to 24 hours depending on the reaction temperature.

Here, the mixing ratio (mass ratio) of the mixed solvent of the specific organic solvent and water in the polymerization step is preferably a ratio with less water than the specific organic solvent from the viewpoint of not inhibiting the progress of the polymerization reaction. It is good to set 98: 2 thru | or 70:30 (desirably 90:10 thru | or 80:20).
Specifically, the mixing ratio (mass ratio) is 96: 4 to 70:30 (preferably 90:10 to 80:20) in the case of a combination of a water-soluble ether solvent and water, and a water-soluble ketone. In the case of a system solvent compound and water, 90:10 to 75:25 (preferably 90:10 to 80:20) is preferable.

(Amine chloride process)
In the amine chlorination step, after the polyimide precursor is generated, an organic amine compound is added to the solvent, and amine chlorination of the polyimide precursor (its carboxyl group) is performed. Thereby, the solubility with respect to the solvent of a polyimide precursor increases.

  In the amine chlorination step, water as a solvent may be added.

(Solvent replacement process)
The solvent replacement step is, for example, to change the solvent composition in the solution after the generation of the polyimide precursor, to stabilize the polyimide precursor composition to be manufactured, to dissolve the polyimide precursor to be generated, and to adjust the solid content concentration, etc. As done.
The solvent replacement step is performed by adding water or other solvent or removing the target solvent. Removal of the solvent includes a method of distilling off the solvent by heating and decompression (distillation method), and a reprecipitation method of separating and removing the solvent after adding water to precipitate the polyimide precursor. . The removal of the solvent may be performed in combination with a distillation method and a reprecipitation method.
Either the solvent replacement step or the solvent composition change step and the amine chlorination step may be performed first. Moreover, you may perform both processes in parallel.
The solvent replacement step is an optional step that does not need to be carried out unless it is necessary to change the solvent composition in the solution after the polyimide precursor is generated.

  Here, when implementing a solvent substitution process, it is good for an amine chlorination process to implement the following 1st amine chlorination processes or a 2nd amine chlorination process.

-Primary amine chlorination step-
In the first amine chlorination step, after the polyimide precursor is generated, water is added to the solvent, the polyimide precursor and the solvent are separated, a part of the separated solvent is removed, and the remainder is water and organic. Add the amine compound.

Specifically, for example, in the first amine chlorination step, when water is excessively added to the solvent after the polyimide precursor is generated, the solubility of the polyimide precursor is reduced and precipitated, resulting in the polyimide precursor and the solvent. And are separated. The amount of water added to the solvent is, for example, 10% by mass to 300% by mass (desirably 50% by mass to 200% by mass) with respect to the total solvent.
If a polyimide precursor and a solvent isolate | separate, a polyimide precursor will settle and a supernatant will become a solvent and a part of solvent after a separation will be removed by removing this supernatant liquid. The removal of a part of the solvent is not limited to the removal of the supernatant liquid, and may be performed by filtration or the like.
Then, when an organic amine compound (for example, an aqueous solution in which the organic amine compound is dissolved) is added to the remainder together with water as a solvent, solvent substitution is performed and amine chloride of the polyimide precursor (its carboxyl group) is performed.
When a 1st amine chlorination process is performed, it will become easy to obtain a highly pure polyimide precursor composition.

-Secondary amine chlorination step-
In the second amine chlorination step, after producing the polyimide precursor, the organic amine compound is added to the remainder after part of the solvent is distilled off or while part of the solvent is distilled off.

Specifically, for example, in the second amine chlorination step, after a polyimide precursor is generated, a part of the solvent is distilled off by heating and reducing the pressure. This evaporation of the solvent is mainly an evaporation of the specific organic solvent. And after distilling off this solvent or adding some organic amine compounds while distilling off a part of the solvent, the solvent composition is changed and amine chloride of the polyimide precursor (its carboxyl group) is carried out. . In addition, when adding an organic amine compound, you may also add water as a solvent.
When the second amine chlorination step is performed, a solvent-substituted polyimide precursor composition is easily obtained in a simple step without passing through the precipitation of the polyimide precursor.

<Usage example of polyimide precursor composition>
The polyimide precursor composition according to this embodiment is used as a coating liquid for forming a polyimide molded body. Examples of the coating liquid for forming a polyimide molded body include a coating liquid for forming a polyimide film, a coating liquid for forming a polyimide film, and the like.
Examples of the polyimide film as the polyimide molded body include a flexible electronic substrate film, a copper-clad laminated film, a laminate film, an electrical insulating film, a porous film for fuel cells, and a separation film.
Examples of polyimide coatings as polyimide moldings include insulating coatings, heat resistant coatings, IC packages, adhesive films, liquid crystal alignment films, resist films, planarization films, microlens array films, wire coating films, optical fiber coating films, etc. Is done.
Examples of other polyimide molded bodies include belt members. Examples of the belt member include a drive belt, a belt for an electrophotographic image forming apparatus (for example, an intermediate transfer belt, a transfer belt, a fixing belt, and a conveyance belt).

<Method for producing polyimide molded body>
A polyimide molded body is obtained by heat-treating the coating film formed by applying the polyimide precursor composition according to the present embodiment on an object to be coated.
The polyimide molded body manufactured using a polyimide precursor composition is not specifically limited. Hereinafter, as an example of a method for producing a polyimide molded body using the polyimide precursor composition according to the present embodiment, a method for producing an endless belt will be described in detail.
The method for producing a polyimide molded body using the polyimide precursor composition according to the present embodiment includes a step of forming a coating film by applying the polyimide precursor composition according to the present embodiment on an object to be coated; The method includes a step of heat-treating the coating film formed on the coating object to form an endless belt, and a step of removing the endless belt from the coating object.

  First, the polyimide precursor composition according to this embodiment is applied to the inner surface or outer surface of the mold. As the mold, for example, a cylindrical metal mold is preferably used. Instead of metal, other molds such as resin, glass, and ceramic may be used. In addition, a glass coat or a ceramic coat may be provided on the surface of the mold, or a silicone-based or fluorine-based release agent may be used.

  Next, the cylindrical metal mold coated with the polyimide precursor composition is dried by placing it in a heated or vacuum environment to volatilize 30% by mass or more, preferably 50% by mass or more of the contained solvent.

Next, imidization treatment is performed on the dried film. Thereby, a polyimide resin layer is formed.
The heating conditions for the imidization treatment are, for example, 150 ° C. or higher and 400 ° C. or lower (preferably 200 ° C. or higher and 300 ° C. or lower). Is done. In the heating reaction, before reaching the final temperature of heating, it is preferable to heat by gradually increasing the temperature stepwise or at a constant rate. The temperature of imidization varies depending on, for example, the types of tetracarboxylic dianhydride and diamine used as raw materials. If imidization is insufficient, the mechanical properties and electrical properties are inferior, so that the imidization is completed. Set.
Thereafter, the cylindrical film formed on the surface is removed from the cylindrical metal mold to obtain an endless belt.

(Polyimide molded product)
The polyimide molded body molded from the polyimide precursor composition according to this embodiment includes a specific organic solvent (water-soluble ether solvent, water-soluble ketone solvent, and water-soluble alcohol solvent) contained in the polyimide precursor composition. And one or more organic solvents selected from (1) and an organic amine compound.
The specific organic solvent (water-soluble ether solvent, water-soluble ketone solvent, and water-soluble alcohol solvent) contained in the polyimide molded body molded from the polyimide precursor composition according to the present embodiment is contained in the polyimide molded body. 1 ppb or more and less than 1%. The specific organic solvent contained in the polyimide molded body is quantified by a gas chromatography method with respect to a gas component generated by heating the polyimide molded body. Similarly, for the organic amine compound contained in the polyimide molded body, the amount of gas generated by heating the polyimide molded body is quantified by a gas chromatography method.

  Examples will be described below, but the present invention is not limited to these examples. In the following description, “part” and “%” are all based on mass unless otherwise specified.

<Example 1>
(Preparation of polyimide precursor composition (A-1), (A-2))
-Polymerization process-
A flask equipped with a stirring bar, a thermometer, and a dropping funnel was charged with 360 g of tetrahydrofuran (hereinafter referred to as THF) and 40 g of water. 41.23 g (205.92 mmol) of 4,4′-diaminodiphenyl ether (hereinafter referred to as ODA: molecular weight 200.24) was added while passing dry nitrogen gas. Stirring while maintaining the solution temperature at 30 ° C., 58.77 g (199.75 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter referred to as BPDA: molecular weight 294.22) Was gradually added. After confirming the dissolution of the diamine compound and tetracarboxylic dianhydride, the reaction was further carried out for 24 hours while maintaining the reaction temperature at 30 ° C. It was 150 Pas when the viscosity of the polyimide precursor solution (solid content 20 mass%) was measured by the method described later.
In addition, the imidation ratio of the produced | generated polyimide precursor was 0.02, and as a result of the measurement of the amount of terminal amino groups as stated above, it had an amino group in all the terminals.

-Amine chloride process-
While stirring the polyimide precursor solution obtained in the polymerization step, 35.62 g (399.5 mmol) of dimethylaminoethanol (hereinafter referred to as DMAEt: molecular weight 89.14) and 400 g of water were added. Thereby, the polyimide precursor aqueous solution in which the polyimide precursor was water-solubilized by amine chloride was obtained.
The obtained polyimide precursor aqueous solution was made into the polyimide precursor composition (A-1). Composition of the obtained polyimide precursor composition (A-1) is as follows: Composition of polyimide precursor composition (A-1)
Solid content: 10% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 360 g / 440 g

-Solvent replacement step-
While stirring the obtained polyimide precursor aqueous solution, the pressure was reduced at 10 mmHg / 30 ° C., and a part of THF was distilled off to obtain a polyimide precursor composition (A-2) having the following composition.
-Composition of polyimide precursor composition (A-2)-
・ Viscosity: 148 Pas
Solid content: 18.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 6/94

  Each measurement is as follows.

(Viscosity measurement method)
The viscosity was measured using an E-type viscometer under the following conditions.
・ Measuring device: E-type rotational viscometer TV-20H (Toki Sangyo Co., Ltd.)
・ Measurement probe: No. Type 3 rotor 3 ° × R14
・ Measurement temperature: 22 ℃

(Solid content measurement method)
The solid content was measured under the following conditions using a suggested thermothermographic apparatus. In addition, solid content was measured as a solid content rate as a polyimide with the measured value of 380 degreeC.
・ Measuring device: Differential thermothermal gravimetric simultaneous measuring device TG / DTA6200 (Seiko Instruments Inc.)
・ Measurement range: 20 ° C to 400 ° C · Temperature increase rate: 20 ° C / min

(Solvent composition, water content in the solvent)
The moisture content in the polyimide precursor composition was measured using a coulometric titration type automatic moisture measuring device (Karl Fischer) under the following conditions. The amount of water in the solvent was calculated by removing the resin content contained in the sample from the measured value. This determined the solvent composition.
・ Measuring device: Coulometric titration type automatic moisture measuring device (Karl Fischer) CA-07 (Mitsubishi Chemical Corporation)
Sample volume: 10 μl

<Evaluation>
Film formation was performed using the obtained polyimide precursor compositions (A-1) and (A-2) to produce films, and the film forming properties were evaluated. Moreover, the mechanical properties (tensile strength, tensile elongation) of the obtained film-forming film were measured.

(Film forming property)
Using the polyimide precursor composition (A-1), a film was formed by the following operation. The film-forming film was evaluated for (1) void marks and (2) surface unevenness / pattern.
Application method: A bar coating method using an application blade in which a spacer is provided so that the application thickness is 100 μm.
・ Coating substrate: 1.1 mmt glass plate ・ Drying temperature: 60 ° C. × 10 minutes ・ Baking temperature: 250 ° C. × 30 minutes

(1) Void traces The presence or absence of void traces on the film-forming film surface was evaluated. The evaluation criteria are as follows.
A: No void mark is observed.
◯: 1 or more and less than 10 void traces can be confirmed on the film forming film surface.
Δ: Ten or more void marks less than 50 are scattered on the surface of the film forming film.
X: Innumerable void traces are uniformly generated on the surface of the film forming film.

(2) Surface unevenness / pattern:
The presence or absence of surface irregularities and patterns generated on the film-forming film surface was evaluated. The evaluation criteria are as follows.
A: No surface unevenness or pattern is observed.
○: Surface unevenness and a pattern can be slightly confirmed on a part of the film-forming film surface (less than 10% of the film-forming film surface area).
(Triangle | delta): Surface unevenness and a pattern can be confirmed in a part of film forming film surface.
X: Surface unevenness and a pattern are uniformly generated on the surface of the film-forming film (10% or more of the surface area of the film-forming film).

(Tensile strength / elongation)
A sample piece was punched from the produced film-forming film using dumbbell No. 3. The sample piece was installed in a tensile tester, and the applied load (tensile strength) and elongation at break (tensile elongation) at which the sample piece was pulled and broken were measured under the following conditions.
・ Test equipment: Tensile tester model 1605 manufactured by Aiko Enijing Co., Ltd. ・ Sample length: 30 mm
・ Sample width: 5mm
・ Tensile speed: 10mm / min

<Examples 2 to 13>
[Preparation of Polyimide Precursor Compositions (A-3) to (A-8), (B-1) to (D-2)]
According to Table 1 and Table 2, except having changed the conditions of a polymerization process, an amine chlorination process, and a solvent substitution process, it carried out similarly to Example 1, and polyimide precursor composition (A-3)-(A-8), (B-1) to (D-2) were produced. However, the solvent substitution step was performed so as to have the viscosity, solid content, and moisture content in the solvent shown in Tables 1 and 2.
And the film forming film was produced like Example 1 and evaluated. The evaluation results are shown in Tables 1 and 2.

  In addition, the polyimide precursor produced | generated in Example 7 did not contain an amino group terminal as a result of the measurement of the amount of terminal amino groups as stated above, and all the terminals have a carboxyl group.

<Example 14: Reprecipitation method>
(Preparation of polyimide precursor composition (E-1))
To the polyimide precursor solution prepared in the polymerization step of Example 1, 10 times the volume of water was added to the solvent of the composition to reprecipitate the polyimide precursor. Thereafter, the supernatant was removed.
Next, 106.86 g (1198.5 mmol) of DMAEt and 900 g of water were added to the remainder so that the treatment rate was 300 mol%. Thereby, the polyimide precursor aqueous solution in which the polyimide precursor was water-solubilized by amine chloride was obtained.
The obtained polyimide precursor aqueous solution was made into the polyimide precursor composition (E-1). The composition of the obtained polyimide precursor composition (E-1) is as follows.
-Composition of polyimide precursor composition (E-1)-
・ Viscosity: 60 Pas
Solid content: 9.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 2/98
-Imidization rate: 0.02

  And using the obtained polyimide precursor composition (E-1), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 2.

<Example 15: Reprecipitation method>
(Preparation of polyimide precursor composition (E-2))
The polyimide precursor composition (E--) was used in the same manner as in Example 14 except that 89.05 g (998.75 mmol) of DMAEt and 900 g of water were added to the remainder after removing the supernatant so that the treatment rate was 250 mol%. 2) was produced. The composition of the obtained polyimide precursor composition (E-2) is as follows.
-Composition of polyimide precursor composition (E-2)-
・ Viscosity: 55 Pas
Solid content: 9.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 2/98
-Imidization rate: 0.02

  And using the obtained polyimide precursor composition (E-2), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 2.

<Example 16: Reprecipitation method>
(Preparation of polyimide precursor composition (E-3))
The polyimide precursor composition (E--) was used in the same manner as in Example 14 except that 71.24 g (799.0 mmol) of DMAEt and 900 g of water were added to the remainder after removing the supernatant so that the treatment rate was 200 mol%. 3) was produced. The composition of the obtained polyimide precursor composition (E-3) is as follows.
-Polyimide precursor composition (composition of E-3-
・ Viscosity: 50 Pas
Solid content: 9.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 2/98
-Imidization rate: 0.02

  Using the obtained polyimide precursor composition (E-3), a film-forming film was produced and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

<Example 17: Distillation method>
(Preparation of polyimide precursor composition (F-1))
While stirring the polyimide precursor solution prepared in the polymerization step of Example 1, the pressure was reduced at 10 mmHg / 30 ° C., and a part of THF was distilled off.
Then, while distilling off a part of the THF, 106.86 g (1198.5 mmol) of DMAEt and 900 g of water were added so that the treatment rate was 300 mol%. The polyimide precursor obtained the polyimide precursor aqueous solution water-solubilized by amine chloride.
Then, distillation was complete | finished and the polyimide precursor aqueous solution which the polyimide precursor water-solubilized by amine chloride was obtained.
The obtained polyimide precursor aqueous solution was made into the polyimide precursor composition (F-1). The composition of the obtained polyimide precursor composition (F-1) is as follows.
-Composition of polyimide precursor composition (F-1)-
・ Viscosity: 80 Pas
-Solid content: 12% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 30/70
-Imidization rate: 0.08

  And the film-forming film was produced and evaluated like Example 1 using the obtained polyimide precursor composition (F-1). The evaluation results are shown in Table 2.

<Example 18: Distillation method>
(Preparation of polyimide precursor composition (F-2))
A polyimide precursor composition was obtained in the same manner as in Example 17, except that 89.05 g (998.75 mmol) of DMAEt and 900 g of water were added so that the treatment rate was 250 mol% while part of THF was distilled off. (F-2) was produced. The composition of the obtained polyimide precursor composition (F-2) is as follows.
-Composition of polyimide precursor composition (F-2)-
・ Viscosity: 70 Pas
Solid content: 9.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 20/80
-Imidization rate: 0.08

  And the film-forming film was produced and evaluated like Example 1 using the obtained polyimide precursor composition (F-2). The evaluation results are shown in Table 2.

<Example 19: Distillation method>
(Preparation of polyimide precursor composition (F-3))
A polyimide precursor composition was obtained in the same manner as in Example 17 except that 71.24 g (799.0 mmol) of DMAEt and 900 g of water were added so that the treatment rate was 200 mol% while part of the THF was distilled off. (F-3) was produced. The composition of the obtained polyimide precursor composition (F-3) is as follows.
-Composition of polyimide precursor composition (F-3)-
・ Viscosity: 60 Pas
Solid content: 9.0% (solid content ratio as polyimide)
Solvent composition ratio: THF / water = 15/85
-Imidization rate: 0.06

  And using the obtained polyimide precursor composition (F-3), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 2.

<Examples 20 to 25>
[Preparation of Polyimide Precursor Compositions (G-1) to (G-2), (H-1) to (H-2), (I-1) to (I-2)]
According to Table 3, the polyimide precursor compositions (G-1) to (G-2), (H-) were the same as in Example 1 except that the conditions of the polymerization step, the amine chlorination step, and the solvent substitution step were changed. 1) to (H-2) and (I-1) to (I-2) were produced. However, the solvent substitution step was performed so as to have the viscosity, solid content, and moisture content in the solvent shown in Table 3.
And the film forming film was produced like Example 1 and evaluated. The evaluation results are shown in Table 3.

<Example 26>
[Preparation of Polyimide Precursor Composition (J-1)]
A polyimide precursor composition (J-1) was produced in the same manner as in Example 1 except that the reaction temperature in the polymerization step was 60 ° C. The imidation ratio of the obtained polyimide precursor was 0.18.
And the film-forming film was produced and evaluated like Example 1 using the obtained polyimide precursor composition (J-1). The evaluation results are shown in Table 3.

<Example 27>
[Preparation of polyimide precursor composition (J-2)]
A polyimide precursor composition (J-2) was produced in the same manner as in Example 1 except that the reaction temperature in the polymerization step was 50 ° C. The imidation ratio of the obtained polyimide precursor was 0.13.
And using the obtained polyimide precursor composition (J-2), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 3.

<Comparative Example 1>
[Preparation of polyimide precursor composition (X-1)]
A flask equipped with a stir bar, thermometer and dropping funnel was charged with 400 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP). 41.23 g (205.92 mmol) of 4,4′-diaminodiphenyl ether (hereinafter referred to as ODA: molecular weight 200.24) was added while passing dry nitrogen gas. Stirring while maintaining the solution temperature at 30 ° C., 58.77 g (199.75 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter referred to as BPDA: molecular weight 294.22) Was gradually added. After confirming the dissolution of the diamine compound and tetracarboxylic dianhydride, the reaction was further carried out for 24 hours while maintaining the reaction temperature at 30 ° C. It was 120 Pas when the viscosity of the polyimide precursor solution (solid content 20 mass%) was measured.
The obtained polyimide precursor solution was designated as a polyimide precursor composition (X-1).

Using the obtained polyimide precursor composition (X-1), a film-forming film was produced and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.
As a result, when the firing temperature was 250 ° C. as in Example 1, NMP remained in the film, so that both the tensile strength and tensile elongation were lower than in Example 1. One of the causes is considered to be that the high-boiling point NMP contained in the polyimide precursor composition (X-1) remains in the film-forming film, thereby causing a decrease in mechanical strength.

<Comparative Example 2>
[Preparation of polyimide precursor composition (X-2)]
The polyimide precursor composition (X-1) produced in Comparative Example 1 was added to 10 volumes of acetone to reprecipitate the polyimide precursor. After filtration, it was dried at 40 ° C./reduced pressure (10 mmHg) for 24 hours. After drying, 200 g of water and 18.03 g (202.20 mmol) of dimethylaminoethanol are added to 50 g of polyimide precursor (101.10 mmol equivalent of carboxyl group), and the mixture is stirred and dissolved at 25 ° C. for 6 hours to obtain a polyimide precursor composition. (X-2) was obtained.

Using the obtained polyimide precursor composition (X-2), a film-forming film was produced and evaluated in the same manner as in Example 1. The results are shown in Table 4.
As a result, the film forming property was as good as in Example 1. As a result of the tensile test, it was found that both the tensile strength and the tensile elongation were lower than those of Example 1.
When the content of NMP remaining in the polyimide precursor composition (X-2) was analyzed by a liquid chromatography method, it was 6% by weight in the solvent. The cause of the decrease in the tensile properties of the film-forming sample using the polyimide precursor composition (X-2) is considered to be due to the remaining NMP in the film formation film as in Comparative Example 1.

<Comparative Example 3>
[Preparation of polyimide precursor composition (X-3)]
An organic amine compound was added during the polymerization step of Comparative Example 1, and polymerization was performed as shown below.
A flask equipped with a stir bar, thermometer, and dropping funnel was charged with 400 g of NMP. While passing dry nitrogen gas, 41.23 g (205.92 mmol) of ODA and 35.62 g (399.5 mmol) of DMEAt were added. Stirring was performed while maintaining the solution temperature at 30 ° C., and 58.77 g (199.75 mmol) of BPDA was gradually added. After confirming the dissolution of the diamine compound and tetracarboxylic dianhydride, the reaction was further carried out for 24 hours while maintaining the reaction temperature at 30 ° C. It was 5 Pas when the viscosity of the polyimide precursor solution (solid content 20% by weight) was measured.
The obtained polyimide precursor solution was defined as a polyimide precursor composition (X-3).
And using the obtained polyimide precursor composition (X-3), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 4.

<Comparative Example 4>
[Preparation of polyimide precursor composition (X-4)]
A polyimide precursor composition (X-4) was produced in the same manner as in Example 1 except that the reaction temperature in the polymerization step was 60 ° C. and the reaction time was 48 hours. As a result, a polyimide precursor resin was deposited. . For this reason, the polyimide precursor composition (X-4) could not be used as a coating liquid. The imidation ratio of the obtained polyimide precursor was 0.22.

<Comparative Example 5>
[Preparation of polyimide precursor composition (X-5)]
A polyimide precursor composition (X-5) was produced in the same manner as in Example 1 except that the amount of DMAEt added in the amine chlorination step was changed to a treatment rate of 40 mol%. A resin precipitated. For this reason, the polyimide precursor composition (X-5) could not be used as a coating liquid.

<Comparative Example 6>
[Preparation of polyimide precursor composition (X-6)]
The solvent added in the amine chlorination step was 150 g of THF and 150 g of water, and the polyimide was removed in the same manner as in Example 1 except that the distillation of THF was completed when the water content in the solvent reached 25% in the solvent replacement step. A precursor composition (X-6) was obtained.
And using the obtained polyimide precursor composition (X-6), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 4.
As a result, the obtained polyimide precursor composition (X-6) has an amine-chlorinated polyimide precursor dispersed therein, and when used as a coating liquid, a homogeneous film-forming film cannot be obtained. Moreover, the mechanical properties of the obtained film-forming film were also lowered.

<Comparative Example 7>
[Preparation of polyimide precursor composition (X-7)]
A polyimide precursor composition (X-7) was obtained in the same manner as in Example 1 except that the amount of DMAEt added in the amine chlorination step was changed to a treatment rate of 520 mol%.
And using the obtained polyimide precursor composition (X-7), it carried out similarly to Example 1, produced the film forming film, and evaluated it. The evaluation results are shown in Table 4.
The obtained polyimide precursor composition (X-7) was partially gelled. Furthermore, when the obtained polyimide precursor composition (X-7) was stored for 24 hours in a room temperature environment, it thickened and gelled after 72 hours, making it unusable as a coating solution.

  From the above results, it can be seen that in this example, better results were obtained in terms of evaluation of film forming properties and mechanical properties than in the comparative example.

  The abbreviations in Tables 1 to 4 are as follows. In Tables 1 to 4, “-” means not added or not implemented, and “→” means the same as the left column.

Tetracarboxylic acid: “BPDA” (3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride), “PMDA” (pyromellitic dianhydride)
-Diamine compound: "ODA"(4,4'-diaminodiphenyl ether), "PDA" (p-phenylenediamine)
Organic amine compounds: DMAEt (dimethylaminoethanol: tertiary amine: boiling point bp 133 ° C. to 134 ° C.), γ-Pyc (γ-picoline: tertiary amine: boiling point bp 145 ° C.), MAEt (N-methylethanolamine: secondary) Amine: boiling point bp 156 ° C.), ETA (2-ethanolamine: primary amine: boiling point bp 170 ° C.)
Solvent: THF (tetrahydrofuran: water-soluble ether solvent: boiling point bp 67 ° C.), DOX (dioxane: water-soluble ether solvent: boiling point bp 102 ° C.), ATN (acetone: water-soluble ketone solvent: boiling point bp 56 ° C.), MEK ( Methyl ethyl ketone: water-soluble ketone solvent: boiling point bp 80 ° C), IPA (isopropanol: water-soluble alcohol solvent: boiling point bp 82 ° C)

  In this example, the “treatment rate” in the amine chlorination step is the amount of organic amine compound (mol%) relative to the theoretical amount of carboxyl groups contained in the polyimide precursor. Here, the theoretical amount of the carboxyl group indicates a value obtained by doubling the molar amount of tetracarboxylic acid contained in the polyimide precursor.

Claims (5)

One or more organic solvents selected from a water-soluble alcohol solvent, a water-soluble ether solvent, and a water-soluble ketone solvent, and a solvent containing water, a repeating unit represented by the following general formula (I) And an imidation ratio of 0.2 or less and an organic amine compound of 50 mol% or more and 500 mol% or less with respect to the carboxyl group contained in the resin are dissolved. The polyimide precursor has a boiling point of 40 ° C. or more and 160 ° C. or less, does not contain an aprotic polar solvent, and contains the water in an amount of 30% by mass to 99.9% by mass with respect to the total solvent. Body composition.

(In general formula (I), A represents a tetravalent organic group, and B represents a divalent organic group.)   2. The polyimide precursor composition according to claim 1, wherein, in the general formula (I), A represents a tetravalent aromatic organic group and B represents a divalent aromatic organic group. The organic amine compound, secondary amine compound, and at least one selected from tertiary amine compound according to claim 1 or polyimide precursor composition according to any one of 2. The polyimide precursor composition according to any one of claims 1 to 3 , wherein the resin includes a resin having an amino group at a terminal. The polyimide precursor composition according to any one of claims 1 to 4 , wherein the resin has a number average molecular weight of 1,000 or more and 100,000 or less.