JP2016027130A - Polyimide precursor composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide precursor composition which, when used to form a film, suppresses whitening of the film.SOLUTION: A polyimide precursor composition containing a polyimide precursor and solvents contains, as the solvents, a solvent (solvent A) being at least one selected from ether-based solvents, ketone-based solvents, amide-based solvents, sulfone-based solvents, heterocyclic solvents, phenol-based solvents, lactone-based solvents and ester-based solvents and having a vapor pressure at 20°C of 50,000 Pa or less, and an alcohol (solvent B). The solvent B is at least one alcohol selected from aromatic alcohols, aliphatic alcohols, or glycol monoether alcohols.SELECTED DRAWING: None

Description

  The present invention relates to a polyimide precursor composition that suppresses whitening of a film when the film is formed.

  Conventionally, polyimides having excellent heat resistance, electrical insulation, wear resistance, chemical resistance, mechanical properties, and the like have been widely used in the fields of electricity, electronic parts, transportation equipment, space, aircraft, and the like.

  When a film is obtained by applying a polyimide precursor or a composition containing polyimide to a substrate and heating and / or drying, the resulting film tends to be easily affected by the environment in which the film is formed. is there. In particular, when coating or the like is performed in a high humidity environment, the solubility of the composition decreases due to moisture absorption before drying, and a polyimide precursor or a polyimide is precipitated, resulting in whitening of the film (whitening). Further, there is a problem in that original polyimide characteristics such as heat resistance and mechanical characteristics cannot be obtained even if drying or heating is performed on a whitened film. Therefore, when forming a film using a polyimide precursor or a composition containing polyimide, it was necessary to devise manufacturing equipment such as introducing dry air or nitrogen gas or reducing humidity.

With respect to such a problem, Patent Document 1 suppresses whitening when forming a polyimide film by including 40% by weight or more of N-vinyl-2-pyrrolidone as a solvent in a composition containing polyimide. Is disclosed.
Patent Document 2 discloses that the composition of polyimide is used as a block to increase the solubility in a solvent and suppress whitening.

JP 2003-292779 A JP 2003-119285 A

However, if a solvent having a reactive group such as N-vinyl-2-pyrrolidone used in Patent Document 1 is used, the mechanical properties of polyimide may be impaired. Further, as in Patent Document 2, if the composition of polyimide is made a block in order to make it soluble in a solvent, there are problems such as an increase in manufacturing cost.
On the other hand, although examination about whitening at the time of forming a film using polyimide like patent documents 1 and 2 was made, examination about a polyimide precursor was not fully done. Since the solubility of a polyimide precursor and a polyimide differs greatly, the method used for whitening suppression of the composition containing a polyimide may not be able to acquire sufficient effect with a polyimide precursor.

  The present invention has been accomplished in view of the above problems, and is to provide a polyimide precursor composition in which whitening of the film does not occur in a film formed using a composition containing a polyimide precursor.

The present invention has the following configuration.
[1] A composition comprising a polyimide precursor and a solvent, wherein the solvent is an ether solvent, ketone solvent, amide solvent, sulfone solvent, heterocyclic solvent, phenol solvent, lactone solvent, and ester solvent. A polyimide precursor composition comprising a solvent (solvent A) having at least one selected from the group consisting of solvents and having a vapor pressure at 20 ° C. of 50000 Pa or less, and alcohol (solvent B).
[2] The polyimide precursor composition according to [1], wherein the solvent B is one or more selected from the group consisting of an aromatic alcohol, an aliphatic alcohol, and a glycol monoether alcohol.
[3] The polyimide precursor composition according to [1] or [2], wherein the solvent B has an octanol / water partition coefficient (logρ) of 0 or more.
[4] The polyimide precursor composition according to any one of [1] to [3], wherein the polyimide precursor has an aliphatic skeleton.

  According to the polyimide precursor composition of the present invention, whitening of the film can be suppressed when the film is formed.

  Hereinafter, embodiments of the present invention will be described in detail. The objects and methods exemplified below are examples (representative examples) of the embodiments of the present invention, and the present invention is not deviated from the gist thereof. It is not limited to these contents.

  The polyimide precursor composition of the present invention includes a polyimide precursor and a solvent. The solvent is at least one selected from the group consisting of ether solvents, ketone solvents, amide solvents, sulfone solvents, heterocyclic solvents, phenol solvents, lactone solvents and ester solvents, and The solvent (solvent A) whose vapor pressure in 20 degreeC is 50000 Pa or less and alcohol (solvent B) are included. The reason why whitening can be suppressed by including the solvent A and the solvent B is presumed to be because the hydrophobicity of the entire composition is increased and moisture absorption is suppressed.

(Solvent A)
The solvent A of the present invention is at least one selected from the group consisting of ether solvents, ketone solvents, amide solvents, sulfone solvents, heterocyclic solvents, phenol solvents, lactone solvents, and ester solvents. And it is a solvent whose vapor pressure in 20 degreeC is 50000 Pa or less. By including the solvent A, the solubility is maintained, and effects such as prevention of precipitation of the polyimide precursor in the film forming step can be obtained.
The vapor pressure at 20 ° C. of the solvent A is usually 50000 Pa or less, preferably 20000 Pa or less, more preferably 10,000 Pa or less, more preferably 5000 Pa or less, and particularly preferably 1000 Pa or less. Moreover, there is no lower limit, and the lower one is preferable, but it is 1 Pa or more, for example. By using the solvent whose vapor pressure of the solvent A is within this range, the polyimide precursor in the composition does not precipitate, and the concentration change of the polyimide precursor composition during application tends to be small. Therefore, there is a tendency to obtain a film excellent in uniformity of components in the film, whitening suppression and smoothness.

The boiling point of the solvent A is not particularly limited, but is preferably 60 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher. Further, it is preferably 300 ° C. or lower, more preferably 280 ° C. or lower, and further preferably 250 ° C. or lower. When the boiling point is within this range, the concentration change of the polyimide precursor composition during film formation such as coating is reduced, and therefore a film excellent in uniformity of components in the film, suppression of whitening, and smoothness can be obtained. There is a tendency. Further, the residual solvent in the film after drying or heating tends to decrease.
Alternatively, the solvent A can be used as a solvent for producing the polyimide precursor, and the solvent A can be used as the solvent for the polyimide precursor composition as it is. In that case, it exists in the tendency for it to become the superposition | polymerization temperature from which the polyimide precursor is easy to be obtained because the boiling point of the solvent A is the said range.

  The octanol / water partition coefficient (log ρ) of the solvent A is not particularly limited, but is preferably 2 or less, more preferably 1.5 or less, and even more preferably 1.0 or less. Moreover, Preferably it is -10 or more, More preferably, it is -5 or more, More preferably, it is -3 or more. When log ρ is within this range, the solubility of the polyimide precursor tends to increase.

  The ratio of the solvent A to the total solvent in the composition is not particularly limited, but is usually 99.9% by mass or less, preferably 99.5% by mass or less, more preferably 99.0% by mass or less. . Moreover, it is 50 mass% or more normally, Preferably it is 70 mass% or more, More preferably, it is 80 mass% or more. When the ratio of the solvent A to the total solvent is within this range, the solubility of the polyimide precursor is increased, and whitening during film formation such as coating tends to be suppressed.

Solvent A selected from the group consisting of ether solvents, ketone solvents, amide solvents, sulfone solvents, heterocyclic solvents, phenol solvents, lactone solvents and ester solvents is one solvent selected from the above. What is necessary is just to use above, and you may use two or more by arbitrary ratios.
Among these, from the viewpoint of the solubility of the polyimide precursor, it is preferably at least one selected from the group consisting of an amide solvent, an ether solvent, and a ketone solvent, and among these, an amide solvent and / or Ether solvents are particularly preferred.

Although the said solvent is not specifically limited, The following are mentioned specifically.
(Ether solvent)
Examples of ether solvents include tetrahydrofuran, 1,4-dioxane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetramethylene glycol dimethyl ether, and anisole.
(Ketone solvent)
Examples of the ketone solvent include acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, and the like.
(Amide solvent)
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.
(Sulfone solvent)
Examples of the sulfone solvent include dimethyl sulfoxide.
(Heterocyclic solvent)
Examples of the heterocyclic solvent include pyridine, picoline, lutidine, quinoline, and isoquinoline.

(Phenolic solvent)
Examples of the phenol solvent include phenol and cresol.
(Lactone solvent)
Examples of the lactone solvent include γ-butyrolactone, γ-valerolactone, and δ-valerolactone.
(Ester solvent)
Examples of ester solvents include ethyl acetate, butyl acetate, ethyl butyrate, butyl butyrate, ethyl lactate, and butyl lactate.

(Solvent B)
The solvent B of the present invention is not particularly limited as long as it is an alcohol.
The vapor pressure of the solvent B at 20 ° C. is not particularly limited, but is preferably 50000 Pa or less, more preferably 20000 Pa or less, still more preferably 10,000 Pa or less, more preferably 5000 Pa or less. Moreover, there is no lower limit, and the lower one is preferable, but it is 1 Pa or more, for example. When the vapor pressure is within this range, a film excellent in uniformity of the polyimide precursor composition and components in the film, whitening suppression, and smoothness tends to be obtained.

The boiling point of the solvent B is not particularly limited, but is preferably 60 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher. Further, it is preferably 300 ° C. or lower, more preferably 280 ° C. or lower, and further preferably 250 ° C. or lower.
When the boiling point is within this range, the concentration change of the polyimide precursor composition at the time of film formation such as coating is reduced, and therefore, a film excellent in uniformity of components in the film, suppression of whitening, and smoothness tends to be obtained. It is in. Furthermore, the residual solvent in the film after drying or heating tends to decrease.

  The octanol / water partition coefficient (log ρ) of the solvent B is not particularly limited, but is preferably 0 or more, more preferably 0.5 or more, and still more preferably 1 or more. Moreover, there is no upper limit and a larger one is preferable. When log ρ is within this range, the influence of moisture on the film is reduced, and whitening during film formation tends to be suppressed.

The ratio of the solvent B to the total solvent is not particularly limited, but is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less. Moreover, 0.1 mass% or more is preferable, 0.5 mass% or more is preferable, and 1.0 mass% or more is more preferable.
When the amount of the solvent B is within this range, the solubility of the polyimide precursor is increased, and whitening during film formation tends to be suppressed.

The solvent B is preferably at least one selected from the group consisting of aromatic alcohols, aliphatic alcohols, and glycol monoether alcohols. These solvents may be used alone or in combination at any ratio.
Especially, since the solubility of a polyimide precursor becomes high, aliphatic alcohol or aromatic alcohol is preferable.
Among aliphatic alcohols, the number of carbon atoms is preferably 4 or more, and more preferably 5 or more. Moreover, it is preferable that it is 20 or less, and it is still more preferable that it is 15 or less. Further, among the aliphatic alcohols, it is preferable to have a ring or a branch, and in the case of a branch, it is particularly preferable that the branch position is β and / or γ. By having an appropriate carbon number and / or substitution position as described above, the solubility of the polyimide precursor tends to increase.

Although the solvent B of this invention is not specifically limited, The following are mentioned specifically.
(Aromatic alcohol)
Examples of the aromatic alcohol include benzyl alcohol, salicyl alcohol, diphenylmethanol, and vanillyl alcohol.

(Aliphatic alcohol)
Examples of the aliphatic alcohol include methanol having 1 carbon; ethanol having 2 carbons; 1-propanol and 2-propanol having 3 carbons; 1-butanol and 2-butanol having 4 carbons; Isobutanol and t-butanol; those having 5 carbon atoms, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-ethyl-1- Propanol and the like; 6 carbon atoms such as 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 2- Methyl-3-pentanol, 2-ethyl-1-butanol, 3-ethyl-2-butanol, 2,3-dimethyl-1-butanol, cyclo Xanol etc .; 7 carbon atoms, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 2-methyl-1-hexanol, 2-methyl-3-hexanol, 2-methyl-4-hexanol, 3 -Methyl-1-hexanol, 3-methyl-2-hexanol, 3-methyl-4-hexanol, 2-ethyl-1-pentanol, 2-ethyl-3-pentanol, 2,2-dimethyl-1-pen Tanol, 2,3-dimethyl-1-pentanol, 2,4-dimethyl-1-pentanol, etc .; 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-methyl having 8 carbon atoms -1-heptanol, 2-methyl-3-heptanol, 2-methyl-4-heptanol, 2-ethyl-1-hexanol, 2- Tyl-3-hexanol, 2-ethyl-4-hexanol, 2-propyl-1-pentanol, 2-propyl-3-pentanol, 2-propyl-4-pentanol, 2,3-dimethyl-1-hexanol 2,4-dimethyl-1-hexanol, etc .; those having 9 carbon atoms, 1-nonanol, 2-nonanol, 3-nonanol, 4-nonanol, 5-nonanol, 2-methyl-1-octanol, 2-methyl- 3-octanol, 2-methyl-4-octanol, 2-methyl-5-octanol, 2-methyl-6-octanol, 2-ethyl-1-heptanol, 2-ethyl-3-heptanol, 2-ethyl-4- Heptanol, 2-ethyl-5-heptanol, 2,6-dimethyl-1-heptanol, 2,6-dimethyl-4-heptanol, 3, 5,5-trimethyl-1-hexanol, 3,5,5-trimethyl-2-hexanol, 2,2,4-trimethyl-1-hexanol, etc .; 10 carbon atoms, 1-decanol, 2-decanol, 3 -Decanol, 4-decanol, 5-decanol, 2-methyl-1-nonanol, 2-methyl-3-nonanol, 2-methyl-4-nonanol, 2-methyl-5-nonanol, 2-ethyl-1-octanol 2-ethyl-3-octanol, 2-ethyl-4-octanol, 2-ethyl-5-octanol, etc .; 11 carbon atoms, 1-dodecanol, 2-dodecanol, 3-dodecanol, 4-dodecanol, 2- Methyl-1-undecanol, 2-ethyl-1-decanol, 2-propyl-1-nonanol, etc .; 1-dodecane having 12 carbon atoms 2-dodecanol, 3-dodecanol, 1-ethyl-1-decanol, 2-ethyl-1-decanol, 3-ethyl-1-decanol, 2-butyl-1-octanol, etc .; 1-tridecanol, 2-tridecanol, 3-tridecanol, 1-ethyl-1-undecanol, 2-ethyl-1-undecanol, 3-ethyl-1-undecanol, 2-butyl-1-nonanol, etc .; -Tetradecanol, 2-tetradecanol, 3-tetradecanol, 2-methyl-1-tridecanol, 2-ethyl-1-dodecanol, 2-propyl-1-undecanol and the like; Decanol, 2-pentadecanol, 3-pentadecanol, 2-methyl-1-tetradecanol, 2-e 1-hexadecanol, 2-hexadecanol, 3-hexadecanol, 2-methyl-1-pentadecanol, 2-carbon, which are carbon 16; lu-1-tridecanol, 2-propyl-1-dodecanol, etc. Ethyl-1-tetradecanol, 2-propyl-1-tridecanol, etc .; carbon 17, 1-heptadecanol, 2-heptadecanol, 3-heptadecanol, 2-methyl-1-hexadecanol, 2-ethyl-1-pentadecanol, 2-propyl-1-tetradecanol, etc .; carbon 18, 1-octadecanol, 2-octadecanol, 3-octadecanol, 2-methyl-1- Heptadecanol, 2-ethyl-1-hexadecanol, 2-propyl-1-pentadecanol, etc .; carbon 19; 1-nonadecanol, 2-nonadecane Canol, 3-nonadecanol, 2-methyl-1-octadecanol, 2-ethyl-1-heptadecanol, 2-propyl-1-hexadecanol, etc .; carbon 20, 1-eicosanol, 2-eicosanol, 3-eicosanol, 2-methyl-1-nonadecanol, 2-ethyl-1-octadecanol, 2-propyl-1-heptadecanol, and the like.

(Glycol monoether alcohol)
Examples of the glycol monoether alcohol include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether.

The vapor pressure difference between the solvent A and the solvent B is not particularly limited, but is preferably 10,000 Pa or less, more preferably 5000 Pa or less, and still more preferably 1000 Pa or less. There is no lower limit, and the vapor pressure difference may be zero. Further, either the solvent A or the solvent B may have a higher vapor pressure.
When the vapor pressure difference is in a specific range, the concentration change of the polyimide precursor composition at the time of film formation such as coating is reduced, so that a film with excellent whitening suppression, uniformity of components in the film and smoothness can be obtained. Tend to be. Further, the residual solvent in the film after drying or heating tends to decrease.

The difference in boiling point between the solvent A and the solvent B is not particularly limited, but is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, and further preferably 50 ° C. or lower. There is no lower limit, and the boiling point difference may be zero. Further, either of the boiling points of the solvent A and the solvent B may be higher.
When the difference in boiling point is within a specific range, the concentration change of the polyimide precursor composition during film formation is reduced, and therefore, a film excellent in suppression of whitening, uniformity of components in the film and smoothness tends to be obtained. is there. Further, the residual solvent in the film after drying or heating tends to decrease.

  The ratio of the ratio of solvent A and solvent B to the total solvent is not particularly limited. Further, the ratio of the solvent B to the solvent A is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less. Moreover, 0.1 mass% or more is preferable, 0.5 mass% or more is preferable, and 1.0 mass% or more is more preferable. When the ratio of the ratio of the solvent A and the solvent B is within this range, the solubility of the polyimide precursor is maintained and the whitening suppression effect tends to be obtained.

  The combination of the solvent A and the solvent B is not particularly limited. When the solvent A is an amide solvent or a ketone solvent, the solvent B is preferably at least one selected from the group consisting of cyclic alcohols or branched aliphatic alcohols, aromatic alcohols, and glycol monoether alcohols. When the solvent A is an ether solvent, the solvent B is preferably an aromatic alcohol or a glycol monoether alcohol. By combining these, the solubility of the polyimide precursor tends to be improved.

(Other solvents)
The polyimide precursor composition of the present invention may contain other solvents other than the solvent A and the solvent B as long as the effects of the invention are not impaired. Examples of other solvents include hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, toluene, xylene, and mesitylene; carbon tetrachloride, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, and fluorobenzene. Halogenated hydrocarbon solvents such as, and the like. These solvents may be used alone or in combination of two or more in any ratio and combination.

(Polyimide precursor)
The polyimide precursor of this invention has a polyamic acid and / or a polyamic acid ester. Moreover, a part of polyimide precursor may have a polyimide structure, and polyamic acid and / or polyamic acid ester and polyimide may be mixed.
Moreover, the polyimide precursor of this invention may be 1 type, and may contain multiple types. These are not necessarily synthesized under the same reaction conditions or have the same solubility in the imidization rate solvent, and may be adjusted under different conditions and may have different physical properties. In this invention, the imidation rate and molecular weight which are mentioned later represent the average value of the polyimide precursor in a polyimide precursor composition.

The polyimide precursor of the present invention is not particularly limited as long as it is soluble in the mixed solvent of the solvent A and the solvent B of the present invention. The main chain of the polyimide precursor is composed of a unit derived from a tetracarboxylic dianhydride compound and a repeating unit derived from a diamine compound.
The structure of the polyimide precursor of this invention is not specifically limited, For example, the structure which has the unit derived from the unit derived from the tetracarboxylic dianhydride compound which is the raw material of the polyimide precursor mentioned later and the diamine compound is mentioned. Among these, from the viewpoint of solubility in a solvent, it preferably has an aliphatic skeleton, and more preferably has an alicyclic structure. In addition, the position of the aliphatic skeleton and the alicyclic structure is not particularly limited, but the polyimide precursor composition and film formation may have a unit derived from a tetracarboxylic dianhydride compound that is a raw material of the polyimide precursor. This is preferable because it tends to be easy to control the viscosity.
In the present invention, “soluble in a solvent” means complete dissolution when the polyimide precursor is dissolved at room temperature (25 ° C.) in the solvent of the polyimide precursor composition. The concentration for complete dissolution is usually 0.5% by mass or more, preferably 1% by mass or more, and more preferably 10% by mass or more.

  The weight average molecular weight (Mw) of the polyimide precursor contained in the polyimide precursor composition is not particularly limited. The weight average molecular weight in terms of polystyrene is usually 1000 or more, preferably 3000 or more, more preferably 5000 or more. Moreover, it is 200000 or less normally, Preferably it is 180000 or less, More preferably, it is 150,000 or less. By being in this range, the solubility of the polyimide precursor in the solvent, the composition viscosity, the melt viscosity and the like tend to be easily handled with ordinary production equipment, which is preferable. The polystyrene-reduced weight average molecular weight can be determined by gel permeation chromatography (GPC).

  The number average molecular weight (Mn) of the polyimide precursor contained in the polyimide precursor composition is not particularly limited. The number average molecular weight in terms of polystyrene is usually 500 or more, preferably 1000 or more, more preferably 2500 or more. Moreover, it is usually 100,000 or less, preferably 90000 or less, more preferably 80000 or less. By being in this range, the solubility of the polyimide precursor in the solvent, the composition viscosity, the melt viscosity and the like tend to be easily handled with ordinary production equipment, which is preferable. The number average molecular weight of the polyimide precursor can be determined by the same method as the weight average molecular weight.

  The molecular weight distribution (PDI: weight average molecular weight / number average molecular weight (Mw / Mn)) of the polyimide precursor contained in the polyimide precursor composition is usually 1 or more, preferably 1.1 or more, more preferably 1.2 or more. It is. Moreover, it is 10 or less normally, Preferably it is 9 or less, More preferably, it is 8 or less. By being in this range, there is a tendency to obtain a film excellent in uniformity of components in the film, whitening suppression and smoothness.

  The imidation ratio of the polyimide precursor contained in the polyimide precursor composition is not particularly limited. Usually, it is less than 100%, preferably 80% or less, more preferably 60% or less, and further preferably 50% or less. There is no lower limit, and the imidization rate may be 0%. When the imidization ratio falls within this range, the solubility in the solvent used for the polyimide precursor composition increases, and the stability of the polyimide precursor composition tends to increase. The imidation ratio of the polyimide precursor contained in the polyimide precursor composition can be determined by a conventionally known method such as an NMR method, an IR method, or a titration method.

(Other components of the polyimide precursor composition)
The polyimide precursor composition of this invention can contain another component in the range which does not impair the effect of this invention other than the polyimide precursor and solvent which were mentioned above. Examples of other components include surfactants, solvents, antioxidants, lubricants, colorants, stabilizers, UV absorbers, antistatic agents, flame retardants, plasticizers, mold release agents, leveling agents, and antifoaming agents. Etc. Moreover, you may mix | blend inorganic type fillers or organic type fillers, such as powder form, a granular form, plate shape, and fibrous form, as long as the objective of invention is not impaired as needed. These additive components may be added at any stage of any process for producing the polyimide precursor composition.

  Among these components, it is preferable to include a leveling agent because the smoothness of the film tends to be improved. Examples of the leveling agent include silicone compounds. The silicone compound is not particularly limited. For example, polyether-modified siloxane, polyether-modified polydimethylsiloxane, polyether-modified hydroxyl group-containing polydimethylsiloxane, polyether-modified polymethylalkylsiloxane, polyester-modified polydimethylsiloxane, polyester-modified hydroxyl group Examples thereof include polydimethylsiloxane, polyester-modified polymethylalkylsiloxane, aralkyl-modified polymethylalkylsiloxane, highly polymerized silicone, amino-modified silicone, amino-derivative silicone, phenyl-modified silicone, and polyether-modified silicone.

(Method for producing polyimide precursor composition)
There is no restriction | limiting in particular in the manufacturing method of a polyimide precursor composition. For example, a method in which the polyimide precursor is dissolved in the entire amount of the solvent A and then the solvent B is added; a method in which the polyimide precursor is dissolved in a mixed solvent of the solvent A and the solvent B; a polyimide precursor is dissolved in a part of the solvent A And adding a solvent in which the remaining solvent A and solvent B are mixed; and the like. There are no restrictions on the order of addition of the solvent A and the solvent B, and the same applies when other solvents are added.

(Production method of polyimide precursor)
The polyimide precursor of the present invention is obtained by reacting a tetracarboxylic dianhydride and a diamine compound in a solvent. The method for reacting the tetracarboxylic dianhydride and the diamine compound in a solvent is not particularly limited. Moreover, the addition order and addition method of a tetracarboxylic dianhydride and a diamine compound are not particularly limited. For example, a polyimide precursor can be obtained by sequentially adding a tetracarboxylic dianhydride and a diamine compound to a solvent and stirring at an appropriate temperature.

  The amount of the diamine compound is usually 0.7 mol or more, preferably 0.8 mol or more, and usually 1.3 mol or less, preferably 1.2 mol or less, relative to 1 mol of tetracarboxylic dianhydride. is there. By making a diamine compound into such a range, it exists in the tendency for the yield of the polyimide precursor obtained to improve.

The concentration of the tetracarboxylic dianhydride and the diamine compound in the solvent can be appropriately set depending on the reaction conditions and the viscosity of the polyimide precursor to be obtained.
The total mass of the tetracarboxylic dianhydride and the diamine compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more with respect to the total amount of the solution containing the tetracarboxylic dianhydride, the diamine compound and the solvent. In general, it is 70% by mass or less, preferably 50% by mass or less. Since the concentrations of the tetracarboxylic dianhydride and the diamine compound are not too low, the molecular weight tends to increase. Further, if it is not too high, the viscosity does not become too high and the solution tends to be easily stirred.

The temperature at which the tetracarboxylic dianhydride and the diamine compound are reacted in the solvent is not particularly limited as long as the reaction proceeds, but is usually 0 ° C or higher, preferably 20 ° C or higher, and usually 120 ° C or lower. The temperature is preferably 100 ° C. or lower.
The reaction time is usually 1 hour or longer, preferably 2 hours or longer, usually 100 hours or shorter, preferably 42 hours or shorter. By carrying out under such conditions, the polyimide precursor tends to be obtained at a low cost and in a high yield.
The pressure during the reaction may be normal pressure, pressurization, or reduced pressure. The atmosphere may be air or an inert atmosphere.

  The solvent used when making tetracarboxylic dianhydride and a diamine compound react is not specifically limited. For example, hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, toluene, xylene, mesitylene, anisole; halogenated carbon tetrachloride, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, fluorobenzene, etc. Hydrocarbon solvents; ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, methoxybenzene; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene Glycol solvents such as glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate; N, N Amide solvents such as dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone; sulfone solvents such as dimethyl sulfoxide; heterocyclic solvents such as pyridine, picoline, lutidine, quinoline, isoquinoline; phenol, cresol Phenol solvents such as γ-butyrolactone, γ-valerolactone, lactone solvents such as δ-valerolactone, and the like. These solvents may be used alone or in combination of two or more in any ratio and combination.

The obtained polyimide precursor may be used as it is, or may be added to a poor solvent to be precipitated in a solid state and then re-dissolved in another solvent to obtain a polyimide precursor composition.
The poor solvent to be used is not particularly limited and may be appropriately selected depending on the type of the polyimide precursor, but ether solvents such as diethyl ether and diisopropyl ether; ketone solvents such as acetone, methyl ethyl ketone, isobutyl ketone and methyl isobutyl ketone; methanol, And alcohol solvents such as ethanol and isopropyl alcohol. Among these, alcohol solvents are preferable because precipitates can be obtained efficiently, the boiling point is low, and drying tends to be easy. These solvents may be used alone or in combination of two or more in any ratio and combination.
The method for re-dissolving the polyimide precursor is not particularly limited. For example, after dissolving the polyimide precursor in the solvent A described above, the method of adding the solvent B, and the polyimide precursor resin in the mixed solvent of the solvent A and the solvent B. The method of making it melt | dissolve etc. are mentioned.

(Raw material of polyimide precursor)
Although the tetracarboxylic dianhydride and diamine compound which are the raw materials of the polyimide precursor of this invention are not specifically limited, Specifically, the following are mentioned.

(Tetracarboxylic dianhydride)
Examples of the tetracarboxylic dianhydride include an aromatic ring-containing tetracarboxylic dianhydride and an aliphatic tetracarboxylic dianhydride. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.
As tetracarboxylic dianhydride having an aromatic ring, tetracarboxylic dianhydride having one aromatic ring in one molecule, tetracarboxylic dianhydride having two or more independent aromatic rings in one molecule And tetracarboxylic dianhydrides having a condensed aromatic ring in one molecule. Among these, since the viscosity at the time of production is easy to control, tetracarboxylic dianhydride having one aromatic ring in one molecule or two or more independent aromatic rings in one molecule. The tetracarboxylic dianhydride having two or more independent aromatic rings in one molecule is particularly preferable.
As the tetracarboxylic dianhydride having two or more aromatic rings in one molecule, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride or 4,4′-oxydiphthalic dianhydride is preferred.

  Examples of the aliphatic tetracarboxylic dianhydride include alicyclic tetracarboxylic dianhydrides and chain aliphatic tetracarboxylic dianhydrides. Among these, alicyclic tetracarboxylic dianhydrides are preferable. Among the alicyclic tetracarboxylic dianhydrides, 3,3 ′, 4,4′-biscyclohexanetetracarboxylic dianhydride or 1,2,4,5-cyclohexanetetracarboxylic dianhydride is It is preferable because the solubility of the polyimide precursor is improved and a film having excellent dimensional stability can be obtained.

(Tetracarboxylic dianhydride having an aromatic ring)
(Tetracarboxylic dianhydride with one aromatic ring in one molecule)
Examples of the tetracarboxylic dianhydride having one aromatic ring in one molecule include pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride. .

(Tetracarboxylic dianhydride having two or more independent aromatic rings in one molecule)
Examples of tetracarboxylic dianhydrides having two or more independent aromatic rings in one molecule include 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3- Dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3 4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4 -Dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3 3'-Ben Phenonetetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 4,4- (p-phenylenedioxy) diphthalic dianhydride, 4,4- (m-phenylenedioxy) diphthalic acid Anhydride, 2,2 ′, 6,6′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoro Propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2′-bis (trifluoromethyl) -4,4 ', 5,5'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluorotrimethylene) -diphthalic dianhydride, 4,4 '-(octafluorotetramethylene) -diphthal Acid dianhydride, 4,4'-oxydi Tal anhydride, and the like.

(Tetracarboxylic dianhydride having a condensed aromatic ring in one molecule)
Examples of tetracarboxylic dianhydrides having a condensed aromatic ring in one molecule include 1,2,5,6-naphthalenedicarboxylic dianhydride, 1,4,5,8-naphthalenedicarboxylic dianhydride, 2, 3,6,7-naphthalenedicarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7 , 8-phenanthrenetetracarboxylic dianhydride and the like.

(Aliphatic tetracarboxylic dianhydride)
(Alicyclic tetracarboxylic dianhydride)
Examples of the alicyclic tetracarboxylic dianhydride include 3,3 ′, 4,4′-biscyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 , 2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-11,2-dicarboxylic anhydride, tricyclo [6.44.0.02,7 Dodecane-1,8: 2,7-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4- ( 2,5-dioxotetrahydrofuran-3-yl) -1,2,3, - tetrahydronaphthalene-1,2-dicarboxylic anhydride, 1,1'-bi cyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride, and the like.

(Chain aliphatic tetracarboxylic dianhydride)
Examples of chain aliphatic tetracarboxylic dianhydrides include ethylene tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, meso-butane-1,2,3,4-tetracarboxylic dianhydride, and the like. Is mentioned.

(Diamine compound)
Examples of the diamine compound include aromatic diamine compounds and aliphatic diamine compounds. These compounds may be used individually by 1 type, or may be used 2 or more types by arbitrary ratios and combinations.
As an aromatic diamine compound, a diamine compound having one aromatic ring in one molecule, a diamine compound having two or more independent aromatic rings in one molecule, a diamine compound having a condensed aromatic ring in one molecule, etc. Is mentioned. Among these, a diamine compound having one aromatic ring in one molecule or a diamine compound having two or more independent aromatic rings is preferable in terms of facilitating viscosity control during production. Particularly preferred are diamine compounds having the following aromatic rings.
As a diamine compound having two or more independent aromatic rings in one molecule, from the viewpoint of solubility, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, (4- (4-aminophenoxy) Phenyl) sulfone, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 2,2-bis (4- (4-Aminophenoxy) phenyl) propane and the like are preferable.
Examples of the aliphatic diamine compound include alicyclic diamine compounds and chain aliphatic diamine compounds. Among these, from the viewpoint of solubility, alicyclic diamine compounds are preferable, and 1,4-diaminocyclohexane or 1,3-bis (aminomethyl) cyclohexane is particularly preferable.

(Aromatic diamine compound)
(Diamine compound with one aromatic ring in one molecule)
Examples of the diamine compound having one aromatic ring in one molecule include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, and the like.

(Diamine compound having two or more independent aromatic rings in one molecule)
Examples of the diamine compound having two or more independent aromatic rings in one molecule include 4,4 ′-(biphenyl-2,5-diylbisoxy) bisaniline, 4,4′-diaminodiphenyl ether, 3,4 '-Diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, (4- (4-aminophenoxy) phenyl) sulfone, 2,2-bis ( 4- (4-aminophenoxy) phenyl) propane, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, 1,3-bis (4-aminophenoxy) ) Neopentane, 4,4′-diamino-3,3′-dimethylbiphenyl, 4,4′-diamino-2,2′-dimethylbiphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, bis (4-amino-3-carboxyphenyl) methane, 4,4′-diaminodiphenylsulfone 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfide, N- (4-aminophenoxy) -4-aminobenzamine, 2,2′-bis (trifluoromethyl) -4,4 ′ -Diaminobiphenyl, bis (3-aminophenyl) sulfone, norbornanediamine, 4,4'-diamino-2- (trifluoromethyl) diphenyl ether, 5-trifluoromethyl-1,3-benzenediamine, 2,2-bis (4- (4-Aminophenoxy) phenyl) hexafluoropropane, 4,4′-diamino-2,2′-bis (to Fluoromethyl) biphenyl, 2,2-bis [4- {4-amino-2- (trifluoromethyl) phenoxy} phenyl] hexafluoropropane, 2-trifluoromethyl-p-phenylenediamine, 2,2-bis ( 3-amino-4-methylphenyl) hexafluoropropane and the like.

(A diamine compound having a condensed aromatic ring in one molecule)
Examples of the diamine compound having a condensed aromatic ring in one molecule include 4,4 '-(9-fluorenylidene) dianiline, 2,7-diaminofluorene, 1,5-diaminonaphthalene, 3,7-diamino-2,8- Examples include dimethyldibenzothiophene 5,5-dioxide.

(Aliphatic diamine compound)
(Alicyclic diamine compounds)
Examples of the alicyclic diamine compound include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 4,4′-methylenebis (2-methylcyclohexylamine) and the like.

(Chain aliphatic diamine compounds)
Examples of chain aliphatic diamine compounds include (1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, 1, 5-diaminopentane, 1,10-diaminodecane, 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butanediamine, 2-methyl-1,5-diaminopentane) and the like. It is done.

(Method for forming a film using a polyimide precursor composition)
A method for forming a film using the polyimide precursor composition of the present invention is not particularly limited, and examples thereof include a method of applying a polyimide precursor composition to a substrate or the like.
Examples of the coating method include die coating, spin coating, screen printing, spraying, a casting method, a method using a coater, a spraying method, a dipping method, a calendar method, and a casting method. These methods can be appropriately selected according to the application area, the shape of the surface to be applied, and the like.

  A method for volatilizing a solvent contained in a film formed by coating or the like is not particularly limited. Usually, the solvent is volatilized by heating the carrier substrate coated with the polyimide resin composition. The heating method is not particularly limited, and examples thereof include hot air heating, vacuum heating, infrared heating, microwave heating, heating by contact using a hot plate or a hot roll, and the like.

  As the heating temperature in the above case, a suitable temperature can be used according to the kind of the solvent. The heating temperature is usually 40 ° C or higher, preferably 60 ° C or higher, and is usually 400 ° C or lower, preferably 350 ° C or lower, more preferably 300 ° C or lower. When heating temperature is 40 degreeC or more, it is preferable at the point from which a solvent is fully volatilized. In addition, when the heating temperature is 400 ° C. or lower, since the organic solvent does not volatilize rapidly, it is possible to prevent bubbles from being generated in the obtained polyimide film. This is preferable because the possibility of reducing the appearance and quality of the obtained film can be reduced. The heating atmosphere may be in air or in an inert atmosphere, and is not particularly limited. However, when the polyimide film is required to be colorless and transparent, it is heated in an inert atmosphere such as nitrogen to suppress coloring. It is preferable.

  The film formed using the polyimide precursor composition of the present invention is particularly excellent in transparency and low colorability, and therefore suitable for applications such as coating materials, surface protective layers, adhesives, device substrates, and insulating films. Can be used.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, the following examples are shown in order to describe the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the gist thereof.

[Example 1]
In a four-necked flask equipped with a nitrogen gas inlet tube, a condenser, and a stirrer, 3,98 '(0.06 mol) 3,3', 4,4'-biscyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4′-biphenyltetracarboxylic dianhydride 6.99 g (0.02 mol), 4,4′-diaminodiphenyl ether 16.02 g (0.08 mol), N-methyl-2-pyrrolidone (NMP) as solvent A 120 g was added. The mixture was heated with stirring and reacted at 80 ° C. for 6 hours to obtain a composition X-1 containing 25% by mass of a polyimide precursor and solvent A.
To 5.0 g of the composition X-1, 0.41 g of 2-methyl-1-pentanol was added as the solvent B and stirred to obtain a polyimide precursor composition 1.
The obtained polyimide precursor composition 1 was applied on a glass substrate washed with acetone and dried to a width of about 3 cm and a length of about 8 cm using an applicator having a thickness of 100 μm, and allowed to stand at 24 ° C. and 70% humidity. did. As a whitening test, the time until the film is completely whitened is measured. A for 60 minutes or more, B for 45 minutes to less than 60 minutes, C for 30 minutes to less than 45 minutes, C, less than 30 minutes The thing was set to D. The results are shown in Table 1.
In addition, the vapor pressure (Pa) and octanol / water partition coefficient (logρ) of each solvent used are shown in Tables 1-3.

[Example 2]
44.57 g (0.15 mol) of 3,3 ′, 4,4′-biscyclohexanetetracarboxylic dianhydride of Example 1 was added to 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. Was synthesized in the same manner as in Example 1 except that 14.4 g (0.05 mol), 4,4′-diaminodiphenyl ether was changed to 40.05 g (0.20 mol), and NMP was changed to 137 g. Composition X-2 containing solvent A was obtained.
To 5.0 g of the composition X-2, 0.41 g of 2-ethyl-1-butanol was added as the solvent B and stirred to obtain a polyimide precursor composition 2. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
A polyimide precursor composition 3 was obtained in the same manner as in Example 1 except that the solvent B of the polyimide precursor composition 1 was changed from 2-methyl-1-pentanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
A polyimide precursor composition 4 was prepared in the same manner as in Example 1 except that the solvent B of the polyimide precursor composition 1 was changed from 2-methyl-1-pentanol to 3,5,5-trimethyl-1-hexanol. Obtained. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
A polyimide precursor composition 5 was obtained in the same manner as in Example 1 except that the solvent B of the polyimide precursor composition 1 was changed from 2-methyl-1-pentanol to 2,6-dimethyl-4-heptanol. . A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 6]
A polyimide precursor composition 6 was obtained in the same manner as in Example 1 except that the solvent B of the polyimide precursor composition 1 was changed from 2-methyl-1-pentanol to cyclohexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 7]
A polyimide precursor composition 7 was obtained in the same manner as in Example 1 except that the solvent B of the polyimide precursor composition 1 was changed from 2-methyl-1-pentanol to 1-decanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 8]
22 g of cyclohexanone was added to 20 g of the composition X-2 obtained in Example 2 to obtain a composition X-3 containing a polyimide precursor and a solvent A. Furthermore, 0.015 g of 2-ethyl-1-butanol was added as a solvent B to 10 g of the composition X-3 to obtain a polyimide precursor composition 8. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 9]
A polyimide precursor composition 9 was obtained in the same manner as in Example 8 except that the solvent B of the polyimide precursor composition 8 was changed from 2-ethyl-1-butanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 10]
A polyimide precursor composition 10 was obtained in the same manner as in Example 8 except that the solvent B of the polyimide precursor composition 8 was changed from 2-ethyl-1-butanol to benzyl alcohol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 11]
A polyimide precursor composition 11 was obtained in the same manner as in Example 8 except that the solvent B of the polyimide precursor composition 8 was changed from 2-ethyl-1-butanol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 12]
22 g of anisole was added to 20 g of the composition X-2 obtained in Example 2 to obtain a composition X-4 containing a polyimide precursor and a solvent A. Furthermore, 0.015 g of 2-ethyl-1-butanol was added as a solvent B to 10 g of the composition X-4 to obtain a polyimide precursor composition 12. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 13]
A polyimide precursor composition 13 was obtained in the same manner as in Example 12 except that the solvent B of the polyimide precursor composition 12 was changed from 2-ethyl-1-butanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 14]
A polyimide precursor composition 14 was obtained in the same manner as in Example 12 except that the solvent B of the polyimide precursor composition 12 was changed from 2-ethyl-1-butanol to benzyl alcohol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 15]
A polyimide precursor composition 15 was obtained in the same manner as in Example 12 except that the solvent B of the polyimide precursor composition 12 was changed from 2-ethyl-1-butanol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 16]
22 g of diethylene glycol dimethyl ether (diglyme) was added to 20 g of the composition X-2 obtained in Example 2 to obtain a composition X-5 containing a polyimide precursor and a solvent A. Furthermore, 0.015 g of benzyl alcohol as a solvent B was added to 10 g of the composition X-5 to obtain a polyimide precursor composition 16. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 17]
A polyimide precursor composition 17 was obtained in the same manner as in Example 16 except that the solvent B of the polyimide precursor composition 16 was changed from benzyl alcohol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 18]
25.26 g (0.08 mol) of 3,3 ′, 4,4′-biscyclohexanetetracarboxylic dianhydride of Example 1 was added to 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. 24.26 g (0.08 mol), 4,4′-diaminodiphenyl ether with 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl 27.22 g (0.09 mol) and 4,4 Synthesis was carried out in the same manner as in Example 1 except that 31.66 g (0.09 mol) of '-diaminodiphenylsulfone was changed to 135 g of NMP to obtain a composition X-6 containing a polyimide precursor and a solvent A. Furthermore, 22 g of cyclohexanone was added to 20 g of the composition X-6 to obtain a composition X-7 containing the polyimide precursor and the solvent A.
To 10 g of the composition X-7, 0.015 g of 2-ethyl-1-butanol was added as the solvent B to obtain a polyimide precursor composition 18. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 19]
A polyimide precursor composition 19 was obtained in the same manner as in Example 18 except that the solvent B of the polyimide precursor composition 18 was changed from 2-ethyl-1-butanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 20]
A polyimide precursor composition 20 was obtained in the same manner as in Example 18 except that the solvent B of the polyimide precursor composition 18 was changed from 2-ethyl-1-butanol to benzyl alcohol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 21]
A polyimide precursor composition 21 was obtained in the same manner as in Example 18 except that the solvent B of the polyimide precursor composition 18 was changed from 2-ethyl-1-butanol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 22]
22 g of anisole was added to 20 g of the composition X-6 obtained in Example 18 to obtain a composition X-8 containing a polyimide precursor and a solvent A. Furthermore, 0.015 g of 2-ethyl-1-butanol was added as a solvent B to 10 g of the composition X-8 to obtain a polyimide precursor composition 22. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 23]
A polyimide precursor composition 23 was obtained in the same manner as in Example 22 except that the solvent B of the polyimide precursor composition 22 was changed from 2-ethyl-1-butanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 24]
A polyimide precursor composition 24 was obtained in the same manner as in Example 22 except that the solvent B of the polyimide precursor composition 22 was changed from 2-ethyl-1-butanol to benzyl alcohol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 25]
A polyimide precursor composition 25 was obtained in the same manner as in Example 22 except that the solvent B of the polyimide precursor composition 22 was changed from 2-ethyl-1-butanol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 26]
22 g of diethylene glycol dimethyl ether (diglyme) was added to 20 g of the composition X-6 obtained in Example 18 to obtain a composition X-9 containing a polyimide precursor and a solvent A. Furthermore, 0.015 g of 2-ethyl-1-butanol was added as a solvent B to 10 g of the composition X-9 to obtain a polyimide precursor composition 26. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 27]
A polyimide precursor composition 27 was obtained in the same manner as in Example 26 except that the solvent B of the polyimide precursor composition 26 was changed from 2-ethyl-1-butanol to 2-ethyl-1-hexanol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 28]
A polyimide precursor composition 28 was obtained in the same manner as in Example 26 except that the solvent B of the polyimide precursor composition 26 was changed from 2-ethyl-1-butanol to benzyl alcohol. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Example 29]
A polyimide precursor composition 29 was obtained in the same manner as in Example 26 except that the solvent B of the polyimide precursor composition 26 was changed from 2-ethyl-1-butanol to ethylene glycol monomethyl ether. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
A comparative composition 1 was obtained in the same manner as in Example 1 except that anisole was added instead of the solvent B of the polyimide precursor composition 1. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 3.

[Comparative Example 2]
A comparative composition 2 was obtained in the same manner as in Example 1 except that N-methyl-2-pyrrolidone was added instead of the solvent B of the polyimide precursor composition 1. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 3.

[Comparative Example 3]
A comparative composition 3 was obtained in the same manner as in Example 12 except that anisole was added instead of the solvent B of the polyimide precursor composition 12. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 3.

[Comparative Example 4]
A comparative composition 4 was obtained in the same manner as in Example 19 except that cyclohexane was added instead of the solvent B of the polyimide precursor composition 19. A whitening test was conducted in the same manner as in Example 1. The results are shown in Table 3.

[Comparative Example 5]
A comparative composition 5 was obtained in the same manner as in Example 26 except that diethylene glycol dimethyl ether (diglyme) was added instead of the solvent B of the polyimide precursor composition 26. A whitening test was conducted in the same manner as in Example 3. The results are shown in Table 3.

  As shown in Tables 1 to 3, it was shown that the polyimide precursor composition of the present invention was suppressed from whitening for 30 minutes or more in a high-humidity coating environment.

  The polyimide precursor composition of the present invention can be used for coating materials, surface protective layers, adhesives, device substrates, insulating films and the like.

Claims (4)

  A composition comprising a polyimide precursor and a solvent, comprising a solvent such as an ether solvent, a ketone solvent, an amide solvent, a sulfone solvent, a heterocyclic solvent, a phenol solvent, a lactone solvent, and an ester solvent. A polyimide precursor composition comprising a solvent (solvent A) having at least one selected from the group and having a vapor pressure at 20 ° C. of 50000 Pa or less, and an alcohol (solvent B).   The polyimide precursor composition according to claim 1, wherein the solvent B is at least one selected from the group consisting of aromatic alcohols, aliphatic alcohols, and glycol monoether alcohols.   The polyimide precursor composition according to claim 1, wherein the solvent B has an octanol / water partition coefficient (logρ) of 0 or more.   The polyimide precursor composition according to any one of claims 1 to 3, wherein the polyimide precursor has an aliphatic skeleton.