WO2014111998A1 - Method for producing polymer solution, and polymer solution - Google Patents

Abstract

A method for producing a polymer solution, comprising the following steps (a) to (d): (a) a synthesis step of reacting an amine component with an acid component in a solvent containing N-methyl-2-pyrrolidone (NMP) to produce a polymer mixture containing a polyimide precursor or a polybenzoxazole precursor; (b) a liquid separation step of adding both water or an aqueous solution and a low-boiling-point solvent to the polymer mixture, and then removing an aqueous layer from the resultant mixture by carrying out a liquid separation procedure to produce a low-boiling-point solvent layer; (c) a step of adding both a displacing solvent and a polar solvent to the low-boiling-point solvent layer; and, subsequent to step (c), (d) a concentration step of distilling the low-boiling-point solvent under a reduced pressure.

Description

Method for producing polymer solution and polymer solution

The present invention relates to a method for producing a polymer solution and a polymer solution. In detail, it is related with the polymer solution used as the material of the heat resistant resin composition used for an electronic component or a display element, and the photosensitive resin composition which has heat resistance.

For the surface protective film and the interlayer insulating film of the semiconductor element, a polyimide resin having excellent heat resistance, electrical characteristics, mechanical characteristics and the like is used. In recent years, semiconductor devices have become more highly integrated and larger, and the mechanical properties, heat resistance, etc. are better than ever due to the thinner and smaller sealing resin packages and the transition to surface mounting by solder reflow. A polyimide resin is required. In addition, polybenzoxazole has attracted attention from the viewpoint of lowering the dielectric constant.

By the way, the polyamic acid which is a precursor of a polyimide resin can be generally obtained by reacting a raw material tetracarboxylic dianhydride and a diamine in an organic solvent.
A polyamic acid ester is also used as a precursor of the polyimide resin. The method for synthesizing the polyamic acid ester is roughly divided into the following three methods.

The first synthesis method is a method of reacting diester dicarboxylic acid dichloride and diamine (see Patent Documents 1 and 2). Since diester dicarboxylic acid dichloride has a higher reactivity with diamine than tetracarboxylic dianhydride, in this synthesis method, a high molecular weight polyamic acid ester can be obtained in a shorter time than polyamic acid. However, since diester dicarboxylic acid dichloride has high reactivity, it easily changes to diester dicarboxylic acid by hydrolysis. Therefore, when water is mixed in the polymerization system, the molecular weight of the resulting polyamic acid ester is lowered, and the reproducibility of the molecular weight becomes poor. There is also a problem that chloride ions remain in the polymer.

The second synthesis method is a method of converting a carboxyl group of a polyamic acid into an ester. After synthesizing polyamic acid from tetracarboxylic dianhydride and diamine, a polyamic acid ester is obtained by adding and reacting a desired esterifying agent (see Patent Document 3).
However, this method has a problem that there is no simple reaction tracking method for esterification, and it is difficult to quantitatively esterify all carboxyl groups.

The third synthesis method is a method in which diester dicarboxylic acid and diamine are polycondensed using a condensing agent. Known condensing agents include carbonyldiimidazole and phosphorus condensing agents. In this method, a high molecular weight polyamic acid ester can be obtained with good reproducibility. However, there is a problem that it is necessary to remove impurities derived from the condensing agent, and it is difficult to obtain a high-purity polyamic acid ester.

On the other hand, the most commonly used method for producing alkali-soluble poly-o-hydroxyamide, which is a polybenzoxazole precursor, is a method in which dicarboxylic acid dichloride is reacted with an appropriate bis-o-aminophenol.
In order to supplement hydrogen chloride generated during the above reaction, a soluble base such as pyridine is usually added.

By the way, in the method for synthesizing the polyimide precursor or polybenzoxazole precursor described above, N-methyl-2-pyrrolidone (NMP) is used as a solvent from the viewpoints of solubility and reactivity of raw materials and products in any method. There are many cases. The polyimide precursor or polybenzoxazole precursor synthesized in NMP is in a state containing chloride ions, condensing agent-derived impurities and residues of active ester part produced during synthesis (polymer mixture) .

From the above polymer mixture, it contains a polyimide precursor or polybenzoxazole precursor and a solvent, and contains substantially no impurities such as by-products and chloride ions during synthesis (for example, about 5% by mass or less). As a method for obtaining a polymer solution, water and / or alcohol is added to a polymer mixed solution, a polyimide precursor or a polybenzoxazole precursor is precipitated, filtered, impurities are removed, and the filtered polyimide precursor or polymer is filtered. There is a method of drying the benzoxazole precursor and dissolving it in an organic solvent different from the synthesis solvent (NMP). The polymer solution obtained by this method can be directly applied to a substrate and cured by heating to form a cured film. Also, a resin composition obtained by adding other components to a polymer solution is applied to a substrate and heated. It can also be cured to form a cured film.

On the other hand, from the viewpoint of safety, it is desired to reduce NMP in the polymer solution or the resin composition. Specifically, for example, the NMP content in the polymer solution or the resin composition is required to be 0.1% or less.

JP 11-315140 A JP 2000-273172 A Japanese Patent Laid-Open No. 10-60109

This invention is made in view of the above, Comprising: The manufacturing method of the polymer solution which can reduce content of a NMP content and the by-product generated at the time of a polyimide precursor or a polybenzoxazole precursor synthesis | combination The purpose is to provide.
Another object of the present invention is to provide a method for producing a polymer solution in which the change in viscosity of the resulting polymer solution is small.

According to the present invention, the following polymer solution production method and the like are provided.
1. A method for producing a polymer solution, comprising the following steps (a) to (d):
(A) A synthesis step in which an amine component and an acid component are reacted in a solvent containing N-methyl-2-pyrrolidone (NMP) to obtain a polymer mixture containing a polyimide precursor or a polybenzoxazole precursor. b) Separation step of adding water or an aqueous solution and a low boiling point solvent to the polymer mixed solution, and removing the aqueous layer by liquid separation operation to obtain a low boiling point solvent layer. (c) Substitution solvent in the low boiling point solvent layer And a step of adding a polar solvent (d) A concentration step of distilling off the low boiling point solvent under reduced pressure after the step (c). 2. The method for producing a polymer solution according to 1, wherein the polar solvent is one or more solvents selected from dimethyl sulfoxide, N-ethylpyrrolidone and dimethylformamide.
3. 3. The production of the polymer solution according to 1 or 2, wherein the low boiling point solvent is one or more solvents selected from isobutanol, ethyl acetate, butyl acetate, diethyl ether, methyl-t-butyl ether, methyl ethyl ketone and methyl isobutyl ketone. Method.
4). 4. The method for producing a polymer solution according to any one of 1 to 3, wherein the substitution solvent is one or more solvents selected from γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether.
5. 5. The method for producing a polymer solution according to any one of 1 to 4, wherein the polyimide precursor or polybenzoxazole precursor has a structure represented by the following general formula (I) or (II).

(In the general formula (I), X represents a tetravalent organic group, p represents an integer of 0 to 2, and W represents a divalent to tetravalent organic group. R ¹ and R ² are each independently hydrogen. An atom, an aliphatic group having 1 to 6 carbon atoms, or a group represented by the following general formula (Ia).

(In general formula (Ia), R ³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 6.)

(In general formula (II), U is a tetravalent organic group, and V is a divalent organic group.)
6). 6. A polymer solution obtained by the method for producing a polymer solution described in any one of 1 to 5 above.
7). 7. The polymer solution according to 6, wherein the content of the polar solvent is 1 to 20% by mass of the whole.
8). 8. The polymer solution according to 6 or 7, wherein the content of nonvolatile components is 10 to 50% by mass of the whole.
9. 9. A resin composition containing the polymer solution described in any one of 6 to 8 above.
10. Curing comprising the steps of applying the polymer solution described in any one of 6 to 8 above or the resin composition described in 9 on a substrate and drying to obtain a resin film, and heating the resin film. A method for producing a membrane.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the polymer solution which can reduce content of NMP and content of the by-product generated at the time of a polyimide precursor or a polybenzoxazole precursor synthesis | combination can be provided.
Moreover, the manufacturing method with which the change with time of the viscosity of the polymer solution obtained becomes small can be provided.

It is a schematic sectional drawing explaining the manufacturing process of the semiconductor device which has a multilayer wiring structure in one Embodiment of this invention.

Hereinafter, the present invention will be described in detail. In this specification, the term “process” is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term “process” is used if the intended action of the process is achieved. included.
The numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

<Method for producing polymer solution>
The method for producing a polymer solution of the present invention includes the following steps (a) to (d).
(A) A synthesis step in which an amine component and an acid component are reacted in a solvent containing N-methyl-2-pyrrolidone (NMP) to obtain a polymer mixture containing a polyimide precursor or a polybenzoxazole precursor. b) Separation step of adding water or an aqueous solution and a low boiling point solvent to the polymer mixed solution, and removing the aqueous layer by a liquid separation operation to obtain a low boiling point solvent layer. (c) A substitution solvent and a low boiling point solvent layer Step of adding polar solvent (d) Concentration step of distilling off the low boiling point solvent under reduced pressure after step (c)

In order to reduce the content of NMP in the polymer solution, it is considered that the solvent used in the synthesis of the polyimide precursor or the polybenzoxazole precursor is replaced with a solvent other than NMP, for example, γ-butyrolactone (BLO). . However, there is a problem that the monomer of the raw material may not dissolve or the synthesis reaction may not proceed. Further, there is a problem that even if a reaction accelerator is added, the accelerator remains without being dissolved.

Moreover, after adding water and / or alcohol in a polymer liquid mixture, depositing a polyimide precursor or a polybenzoxazole precursor, and filtering and drying, the recovered precursor is an organic solvent different from the NMP solvent, for example, A method of dissolving in BLO to form a polymer solution is also conceivable. However, with this method, it is difficult to reduce NMP to 1% or less.

The present invention provides a polymer solution in which the content of NMP and the content of by-products generated during synthesis of the polyimide precursor or polybenzoxazole precursor are reduced by combining the steps (a) to (d). Has been found to be obtained. Moreover, it discovered that the time-dependent change of the viscosity of the polymer solution obtained became small.
Hereinafter, it demonstrates along each process.

<(A) Synthesis process>
In the synthesis step, an amine component and an acid component are reacted with N-methyl-2-pyrrolidone (NMP) as a solvent to obtain a polymer mixed solution containing a polyimide precursor or a polybenzoxazole precursor.
Examples of the polyimide precursor include polyamic acid or polyamic acid ester. Examples of the polybenzoxazole precursor include poly-o-hydroxyamide.

(Polyamide acid)
The polyamic acid is obtained, for example, by reacting a tetracarboxylic dianhydride that is an acid component with a diamine compound that is an amine component. For example, polyamic acid can be synthesized according to the following method.
First, a diamine compound is dissolved in an organic solvent. To this solution, a diamine compound and an equimolar amount of tetracarboxylic dianhydride are gradually added, and the reaction is carried out with stirring using a mechanical stirrer. When using an end-capping agent, after adding tetracarboxylic dianhydride, after stirring at the required temperature and the required time, the end-capping agent may be added gradually or added all at once to react. You may let them.

Examples of the diamine compound include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfide, benzidine, m-phenylenediamine, and p-phenylenediamine. 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis (4-aminophenoxyphenyl) sulfone, bis (3-aminophenoxyphenyl) sulfone, bis (4-aminophenoxy) biphenyl, bis [4- (4 -Aminophenoxy) phenyl] ether, aromatic diamine compounds such as 1,4-bis (4-aminophenoxy) benzene,
Silicone groups such as LP-7100, X-22-161AS, X-22-161A, X-22-161B, X-22-161C and X-22-161E (all trade names manufactured by Shin-Etsu Chemical Co., Ltd.) Containing diamine compounds,
3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, bis (3-amino-4-hydroxyphenyl) propane, bis (4-amino-3 -Hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone, 2,2-bis (3-amino-4-hydroxyphenyl) -1, Hydroxyl groups such as 1,1,3,3,3-hexafluoropropane, 2,2-bis (4-amino-3-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane And diamine compounds.
Among these, the diamine compound having the hydroxyl group is preferable, and 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane is more preferable. The diamine compound is not limited to these. These compounds can be used alone or in combination of two or more.

Examples of tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenonetetra Carboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 1,1-bis ( 3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2 , 3-Dicarbo Ciphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid Dianhydride, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid Dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetra Examples thereof include carboxylic dianhydride and 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride. These are used alone or in combination of two or more. The tetracarboxylic dianhydride is not limited to these.

Among the above tetracarboxylic dianhydrides, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic acid Dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′- Benzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, N- (trimellitic acid The dianhydride) -2,2′-bis (3-amino-4-hydroxyphenyl) hexafluoropropane is preferred for obtaining good film properties with high heat resistance, and bis (3,4-dicarboxyphene). Le) ether dianhydride is more preferred.

In the synthesis of polyamic acid, NMP alone or a mixed solvent of NMP and an organic solvent is used as the solvent.
Examples of the organic solvent mixed with NMP include N, N-dimethylacetamide, N, N-dimethylformamide, N-acetyl-2-pyrrolidone, hexamethylphosphortriamide, dimethylimidazolidinone, N-acetyl-ε- Caprolactam can be used.

In the synthesis of the polyamic acid, the amine component and the acid component are preferably reacted at a molar ratio (amine component / acid component) of 0.5 to 1.5, more preferably 0.75 to 1.25. .
The reaction temperature is preferably −20 to 100 ° C., more preferably 10 to 50 ° C. The reaction time is preferably 0.5 to 100 hours, more preferably 2 to 24 hours.

(Polyamide ester)
The polyamic acid ester is obtained, for example, by reacting a tetracarboxylic acid diester dichloride that is an acid component with a diamine that is an amine component. For example, a polyamic acid ester is prepared by mixing a tetracarboxylic dianhydride and a hydroxy group-containing compound and reacting to produce a tetracarboxylic acid half ester, then acidifying with a halogenating agent, and then reacting with a diamine. The tetracarboxylic acid half ester can be synthesized by a method, a method in which a carbodiimide is used as a condensing agent, and a diamine.

As the tetracarboxylic dianhydride that is the acid component of the polyamic acid ester, the same ones as in the synthesis of the polyamic acid can be used.
As the amine component of the polyamic acid ester, a diamine compound similar to the synthesis of the polyamic acid can be used.

In the formation of the polyamic acid half ester, aliphatic alcohols such as methanol, ethanol, propanol, and butanol can be used as the hydroxy group-containing compound.
As the halogenating agent for halogenating the polyamic acid half ester, thionyl chloride, phosphoryl chloride, phosphorous oxychloride, phosphorous pentachloride, etc., which are used in the usual acid chlorideation reaction of carboxylic acid, can be used.

Any carbodiimide condensing agent for reacting a polyamic acid half ester with a diamine can be used without particular limitation as long as it is used for ordinary active ester synthesis, but dicyclohexylcarbodiimide, diisopropylcarbodiimide, N- [3- (dimethylamino). ) Propyl] -N-ethylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and the like.

In the synthesis of the polyamic acid ester, NMP alone or a mixed solvent of NMP and the organic solvent described above is used as the solvent. The amount of the solvent used is preferably 100 parts by weight or more and 1500 parts by weight or less with respect to 100 parts by weight of the obtained polymer.
In the synthesis of the polyamic acid ester, the amine component and the acid component are preferably reacted at a molar ratio (amine component / acid component) of 0.5 to 1.5, more preferably 0.75 to 1.25. preferable.
The reaction temperature for the synthesis of the polyamic acid ester is preferably −10 to 90 ° C., more preferably 0 to 70 ° C. The reaction time is preferably 8 hours to 1 week, more preferably 10 hours to 42 hours.

(Polybenzoxazole precursor)
The polybenzoxazole precursor is obtained, for example, by reacting a dicarboxylic acid dihalide that is an acid component with a dihydroxydiamine compound that is an amine component. For example, it can be synthesized by converting a dicarboxylic acid derivative into a dihalide derivative and then reacting with the diamine compound. As the dihalide derivative, a dichloride derivative is preferable.

Examples of the dicarboxylic acid include isophthalic acid, terephthalic acid, 2,2-bis (4-carboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 4,4′-dicarboxybiphenyl, 4, 4′-dicarboxydiphenyl ether, 4,4′-dicarboxytetraphenylsilane, bis (4-carboxyphenyl) sulfone, 2,2-bis (p-carboxyphenyl) propane, 5-tert-butylisophthalic acid, 5- Aromatic dicarboxylic acids such as bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3 -Aliphatic dicarboxylic acids such as cyclopentanedicarboxylic acid, oxalic acid, malonic acid, succinic acid, dodecanedioic acid Such as carboxylic acid, and the like.
Among these, 4,4′-dicarboxydiphenyl ether or aliphatic dicarboxylic acid is preferable, and 4,4′-dicarboxydiphenyl ether or dodecanedioic acid is more preferable.
However, it is not limited to these. These compounds can be used alone or in combination of two or more.

As the dihydroxydiamine compound, a diamine having a hydroxyl group that can be used in the synthesis of the polyamic acid described above can be used.
The dihalide derivative can be synthesized by acting a halogenating agent on the dicarboxylic acid derivative. As the halogenating agent, thionyl chloride, phosphoryl chloride, phosphorus oxychloride, phosphorus pentachloride, etc., which are used in the usual acid chlorideation reaction of carboxylic acid can be used.

As a method of synthesizing the dihalide derivative, it can be synthesized by reacting the dicarboxylic acid derivative and the halogenating agent in a solvent or by reacting in an excess halogenating agent and then distilling off the excess. As the reaction solvent, N-methyl-2-pyrrolidone, N-methyl-2-pyridone, N, N-dimethylacetamide, N, N-dimethylformamide, toluene, benzene and the like can be used.

The amount of these halogenating agents used is preferably 1.5 to 3.0 mol, more preferably 1.7 to 2.5 mol, based on the dicarboxylic acid derivative when the reaction is carried out in a solvent. When the reaction is carried out in a halogenating agent, 4.0 to 50 mol is preferable, and 5.0 to 20 mol is more preferable. The reaction temperature is preferably −10 to 70 ° C., more preferably 0 to 20 ° C.

The reaction between the dihalide derivative and the diamine compound is performed in NMP or in a mixed solvent of NMP and the above-described organic solvent in the presence of a dehydrohalogenating agent. As the dehydrohalogenating agent, organic bases such as pyridine and triethylamine are usually used.
The diamine compound and dihalide derivative are preferably reacted at a molar ratio (amine component / dihalide derivative) of 0.5 to 1.5, more preferably 0.75 to 1.25.
The reaction temperature is preferably −10 to 30 ° C., more preferably 0 to 20 ° C. The reaction time is preferably 3 to 24 hours, more preferably 6 to 12 hours.

The polybenzoxazole precursor can also be synthesized by a method via a dicarboxylic acid active ester. Specifically, the dicarboxylic acid is reacted in the presence of dicyclohexylcarbodiimide and 1-hydroxy-benzotriazole. In this reaction, a polybenzoxazole precursor can be obtained by once forming an active ester with an aromatic dicarboxylic acid and 1-hydroxy-benzotriazole and then reacting with a diamine having a hydroxyl group.

As the dicarboxylic acid used in the above reaction, the dicarboxylic acid described in the synthesis of the polybenzoxazole precursor can be used.
As a diamine compound, the diamine which has a hydroxyl group which can be used by the synthesis | combination of the polyamic acid mentioned above can be used.

The reaction between the dicarboxylic acid active ester and the diamine compound is performed in NMP or in a mixed solvent of NMP and the organic solvent described above.
The diamine compound and the dicarboxylic acid active ester are preferably reacted at a molar ratio (amine component / acid active ester) of 0.5 to 1.5, more preferably 0.75 to 1.25.
The reaction temperature is preferably 0 to 90 ° C, more preferably 20 to 75 ° C. The reaction time is preferably 3 hours to 3 days, more preferably 6 hours to 24 hours.

Both ends of each polyimide precursor or polybenzoxazole precursor described above may be an acidic functional group or a derivative group thereof. As a method for making both ends into acidic functional groups or derivatives thereof, the above-described diamine component and acid component may be reacted at a molar ratio (amine component / acid component) of 1 to 1.5. More preferably, the ratio is from .05 to 1.25. In this case, both terminal portions of the obtained precursor are carboxy groups.

The carboxy group can be further substituted with another acidic functional group or a derivative group thereof.
As a specific method for introducing a functional group into a terminal carboxy group, a method of adding a monoamino compound having a functional group or capable of introducing a functional group at the time of synthesizing a precursor may be mentioned.

Examples of the monoamino compound include ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, t-butylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, cyclohexylmethyl. Examples thereof include aliphatic amines such as amines, and aromatic amines such as aniline, o-toluidine, m-toluidine, p-toluidine, o-aminophenol, m-aminophenol and p-aminophenol. The monoamino compound is not necessarily limited to these.
Among them, from the viewpoint of stability, a monoamino compound having an acidic functional group such as a phenolic hydroxyl group such as o-aminophenol, m-aminophenol, and p-aminophenol is added, and the terminal is an acidic functional group or a derivative group thereof. It is preferable to do.

In the present invention, the polyimide precursor or polybenzoxazole precursor is preferably a compound having a structure represented by the following general formula (I) or (II) from the viewpoint of solubility in a developer.

(In the general formula (I), X represents a tetravalent organic group, p represents an integer of 0 to 2, and W represents a divalent to tetravalent organic group. R ¹ and R ² are each independently hydrogen. It is an atom, an aliphatic group having 1 to 6 carbon atoms, or a group represented by the following general formula (Ia).

(In general formula (Ia), R ³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 6.)

(In general formula (II), U is a tetravalent organic group, and V is a divalent organic group.)

In the general formula (I), the tetravalent organic group as X is a residue of tetracarboxylic dianhydride as a raw material. Specifically, a tetravalent aromatic group or a tetravalent aliphatic group is preferable. The number of carbon atoms is preferably 4 to 40. A tetravalent aromatic group having 4 to 40 carbon atoms or a tetravalent aliphatic group having 4 to 40 carbon atoms is more preferable.

p represents an integer of 0 to 2, and 0 to 2 hydroxy groups are bonded to W.
The divalent to tetravalent organic group that is W is a residue of a diamine that is a raw material, and is preferably a divalent to tetravalent aromatic group or a divalent to tetravalent aromatic group aliphatic group. Is more preferably a divalent to tetravalent aromatic group of 4 to 40.
R ¹ and R ² are preferably hydrogen, an alkyl group having 1 to 6 carbon atoms, or a group represented by the above general formula (Ia).

The content of the structural unit represented by the general formula (I) in the precursor is preferably 60 to 100 mol%, and more preferably 80 to 100 mol%.

In the general formula (II), the tetravalent organic group represented by U is a diamine residue which is a raw material and has a structure in which two hydroxy groups are located at the ortho positions of the amine. U is preferably a tetravalent aromatic group and preferably has 6 to 40 carbon atoms. In particular, a tetravalent aromatic group having 6 to 40 carbon atoms is preferable. As the tetravalent aromatic group, those in which all four bonding sites are present on the aromatic ring are preferable.

The divalent organic group represented by V is a residue of a dicarboxylic acid that is a raw material, and is preferably a divalent aromatic group or a divalent aliphatic group, and has 6 to 40 carbon atoms. preferable. In particular, a divalent aromatic group having 6 to 40 carbon atoms or a divalent aliphatic group is more preferable.

The content of the structural unit represented by the general formula (II) in the precursor is preferably 60 to 100 mol%, and particularly preferably 80 to 100 mol%.

The polybenzoxazole precursor preferably has a structure represented by the general formula (II). However, since the solubility of the polybenzoxazole precursor in an alkaline aqueous solution is derived from a phenolic hydroxyl group, an amide containing a hydroxy group It is preferable that the unit is contained in a certain proportion or more. That is, a polybenzoxazole precursor represented by the following formula (III) is preferable.

(In the formula, U represents a tetravalent organic group, V and Y each represent a divalent organic group, j and k represent a mole fraction, and the sum of j and k is 100 mol%; j is 60 to 100 mol%, and k is 40 to 0 mol%.)

In the general formula (III), U and V are the same as those in the general formula (II).
The divalent organic group represented by Y is a residue of a diamine that is a raw material, and is a residue other than the diamine that forms U. Y is preferably a divalent aromatic group or a divalent aliphatic group, and preferably has 4 to 40 carbon atoms, more preferably a divalent aromatic group having 4 to 40 carbon atoms. . Further, j is preferably 80 to 100 mol%, and k is preferably 20 to 0 mol%.

The weight average molecular weight (Mw) of the polyimide precursor or polybenzoxazole precursor in the present invention is 5000 to 100,000 in terms of polystyrene. Preferably it is 7000 to 80,000, more preferably 10,000 to 60,000. In order to improve heat resistance, 5000 or more is preferable. On the other hand, 100,000 or less is preferable in terms of solubility in a solvent and handleability.

The polymer mixture of the polyimide precursor or polybenzoxazole precursor obtained in this step is composed of the polyimide precursor or polybenzoxazole precursor, NMP, by-products (hydrochloride, etc.) and impurities in the synthesis step. Including. At this stage, a large amount (for example, 50% by mass or more) of NMP is contained in the polymer mixed solution.
In addition, for example, hydrochloride which is a by-product is generated from hydrochloric acid generated by the reaction of dicarboxylic acid dichloride and diamine, and a base such as pyridine added as a hydrochloric acid trapping agent.

<(B) Separation process>
In this step, water or an aqueous solution and a low boiling point solvent are added to the polymer mixture obtained in the above step (a), and the aqueous layer is removed by a liquid separation operation to obtain a low boiling point solvent layer. By this step, impurities such as hydrochloride generated during synthesis of the polyimide precursor or polybenzoxazole precursor and NMP as a solvent can be removed.

A liquid separation process can be implemented with the following method, for example.
First, a low boiling point solvent is appropriately added so that the solid content (polyimide precursor or polybenzoxazole precursor) content is 3 to 30% by mass of the polymer mixture.
The low boiling point solvent can be separated into a layer containing NMP-containing solvent and water or an aqueous solution added in this step, dissolves the polyimide precursor or polybenzoxazole precursor, and is used as a substitution solvent and a polar solvent in the subsequent step. Any organic solvent having a lower boiling point is not particularly limited. The boiling point of the low boiling point solvent is not particularly limited, but is preferably 180 ° C. or lower.

Examples of the low boiling point solvent include isobutanol, ethyl acetate, butyl acetate, diethyl ether, methyl-t-butyl ether, methyl ethyl ketone, methyl isobutyl ketone, hexane and benzene. In addition, you may use organic solvents other than the above, and each may be used individually or may be used in mixture.
Among these, ethyl acetate, methyl isobutyl ketone, or methyl t-butyl ether is preferable from the viewpoints of volatility, solubility of the polyimide precursor or polybenzoxazole precursor, and layer separation from the aqueous layer.

Next, water or an aqueous solution is added to the polymer mixed solution to which the low boiling point solvent is added.
Examples of the aqueous solution include an aqueous solution of an inorganic acid, an organic acid, or an inorganic salt, and specific examples include ion-exchanged water, hydrochloric acid aqueous solution, sulfuric acid aqueous solution, nitric acid aqueous solution, acetic acid aqueous solution, oxalic acid aqueous solution, and sodium chloride aqueous solution. . An aqueous solution other than the above may be used. Of these, ion-exchanged water is preferred.
The addition amount of water or an aqueous solution is preferably 10 to 200% by mass with respect to the whole polymer mixed solution to which the low boiling point solvent is added.

・ Stir after adding water or aqueous solution. The stirring time is preferably 5 to 60 minutes, more preferably 10 to 20 minutes.

After stirring, the mixture is allowed to stand to separate into two layers of a low boiling point solvent layer (upper layer) and an aqueous layer (lower layer). Of these two separated layers, the aqueous layer is removed by a liquid separation operation.
The low boiling point solvent layer contains a polyimide precursor or polybenzoxazole precursor and a low boiling point solvent. The water layer contains a water-soluble compound, for example, impurities such as chloride ions produced as a by-product during synthesis of the polyimide precursor or polybenzoxazole precursor, NMP, and water.
The standing time after stirring is the time until separation is completed, and is usually 10 minutes to 2 hours, but is not particularly limited. By this step, a low boiling point solvent layer containing a polyimide precursor or a polybenzoxazole precursor and a low boiling point solvent can be obtained.

In addition, you may perform a liquid separation process in multiple times as needed. By performing the treatment a plurality of times, NMP and the like can be further removed, and the content of NMP and impurities in the finally obtained polymer solution can be reduced.
Moreover, after adding water or aqueous solution and a low boiling-point solvent and liquid-separating, you may perform the process of liquid-separating only with water or aqueous solution in multiple times.
Furthermore, in the above description, water or an aqueous solution is added after adding a low-boiling point solvent. However, a low-boiling point solvent may be added after adding water or an aqueous solution.

<(C) Step of adding a substitution solvent and a polar solvent to the low boiling point solvent layer>
In this step, a substitution solvent and a polar solvent are added to the low boiling point solvent layer obtained in the step (b) described above. In addition, there is no restriction | limiting in the order which adds a substituted solvent and a polar solvent, which may be first and may be simultaneous.

The substitution solvent used in this step is the main component of the solvent of the finally obtained polymer solution. The substitution solvent is not particularly limited as long as it is an organic solvent that dissolves a polyimide precursor or a polybenzoxazole precursor and has a boiling point higher than that of the low boiling point solvent used in the previous step.
Specifically, γ-butyrolactone (GBL), ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N, N-dimethylformamide, N, N-dimethylacetamide, hexamethylphosphorylamide, tetramethylene sulfone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, etc. Is mentioned. These solvents can be used alone or in combination of two or more.

Among these, from the viewpoint of solubility of the polyimide precursor or polybenzoxazole precursor, it is preferable to use γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, or propylene glycol monomethyl ether.
The amount of the substitution solvent is not particularly limited, but it is preferably adjusted so that the proportion of the substitution solvent in the finally obtained polymer solution is 20 to 90% by mass.

The polar solvent used in this step has a role of preventing the viscosity of the polymer solution from changing with time. Conventionally, the main component of the solvent in the polymer solution is NMP. However, when the content of NMP is reduced from the viewpoint of safety, there is a problem that the viscosity of the polymer solution changes with time. The polar solvent used in this step can prevent hydrogen bonding between the molecules of the polyimide precursor or polybenzoxazole precursor. As a result, it is considered that the change in the viscosity of the polymer solution with time can be prevented.

Examples of the polar solvent include dimethyl sulfoxide (DMSO), N-ethylpyrrolidone (NEP), and dimethylformamide (DMF). Among these, it is preferable to use DMSO and NEP from the viewpoint that the change in viscosity with time can be prevented.
The blending amount of the polar solvent is not particularly limited. It is preferable to adjust the ratio of the polar solvent in the finally obtained polymer solution to be 1 to 20% by mass.

<(D) Concentration step>
In this step, the low boiling point solvent is distilled off under reduced pressure from the low boiling point solvent layer to which the substitution solvent and the polar solvent are added in the step (c), and concentrated. In the concentration step, the low boiling point solvent and residual moisture can be removed to obtain a polymer solution.

The method for the concentration step is not particularly limited. For example, the low-boiling solvent layer after step (c) may be decompressed using a vacuum pump and concentrated under reduced pressure at a temperature of 20 to 100 ° C. and a temperature of 30 to 60 ° C. for 12 hours to 1 week. About 3 days is more preferable.
In addition, after a concentration process, you may dilute with a low boiling-point solvent and / or a substitution solvent, if necessary, and may adjust a volatile matter density | concentration.

By the above steps (a) to (d), it is possible to obtain a polymer solution in which the content of NMP is extremely small and by-products generated during synthesis of the polyimide precursor or polybenzoxazole precursor are highly removed. In addition, a polymer solution having a small change in viscosity with time can be obtained.

<Polymer solution and resin composition>
The polymer solution of the present invention is obtained, for example, by the production method of the present invention described above.
In the polymer solution of the present invention, for example, the content of NMP in the polymer solution is as low as 0.1% by mass or less, and impurities (for example, chloride ions) produced as a by-product during the synthesis of the polyimide precursor or polybenzoxazole precursor are also present. Less (for example, 0.1% by mass or less). Further, the obtained polymer solution is a polymer solution in which the change in viscosity with time is small.

In the polymer solution of the present invention, the volatile content is preferably 50 to 90% by mass. When the volatile component is within this range, the polymer solution or a resin composition obtained by adding other components to the polymer solution is applied to a substrate, and is cured to form a cured film by heating and curing. It is easy to form a film (0.1 μm to 50 μm). In addition, the volatile matter concentration in the polymer solution can be determined by quantifying the volatile matter (the above-mentioned substitution solvent and polar solvent) by gas chromatography.

The resin composition of the present invention contains the polymer solution of the present invention. The resin composition of the present invention may newly contain a solvent as necessary, and may contain a photosensitizer, an acid generator, a radical initiator, an adhesion assistant, a crosslinking agent, and the like. .

<Method for producing cured film>
The manufacturing method of the cured film of this invention includes the process of apply | coating and drying the polymer solution or resin composition of this invention mentioned above on a base material, and obtaining a resin film, and the process of heating a resin film. The technical scope of the present invention extends to a cured film obtained by the above production method.
In the step of obtaining a resin film, a polymer solution or a resin composition is spin-coated using a spinner or the like on a substrate such as a glass substrate, a semiconductor, a metal oxide insulator (TiO ₂ , SiO _2, or the like) or silicon nitride. Thereafter, a resin film is formed by drying using a hot plate, an oven, or the like.
The resin film may be a patterned resin film by a known exposure process and development process.

In the step of heating the resin film, a cured film is obtained by heat-treating the resin film at 150 to 450 ° C. A diffusion furnace, an oven, a hot plate, or the like can be used for the heat treatment.
The time for thermally curing the resin film is the time until the remaining solvent and volatile components are sufficiently scattered, but is approximately 5 hours or less in consideration of work efficiency. The atmosphere for the heat treatment can be selected from the air or an inert atmosphere such as nitrogen.
The cured film thus obtained can be used as a surface protective layer, an interlayer insulating layer, a rewiring layer, or the like in a semiconductor device.

An example of a manufacturing process of a semiconductor device (electronic component) using the polymer solution or resin composition of the present invention will be described below. FIG. 1 is a manufacturing process diagram of a semiconductor device having a multilayer wiring structure.
In FIG. 1, a semiconductor substrate 1 such as a Si substrate having circuit elements is covered with a protective film 2 such as a silicon oxide film except for a predetermined portion of the circuit elements, and a first conductor layer 3 is formed on the exposed circuit elements. Has been. An interlayer insulating film layer 4 such as a polyimide resin as an interlayer insulating film is formed on the semiconductor substrate by a spin coat method or the like (step (a) in FIG. 1).

Next, a chlorinated rubber-based or phenol novolak-based photosensitive resin layer 5 is formed on the interlayer insulating film layer 4 by spin coating, and a predetermined portion of the interlayer insulating film layer 4 is exposed by a known photolithography technique. A window 6A is provided (step (b)). The interlayer insulating film 4 exposed through the window 6A is selectively etched by dry etching means using a gas such as oxygen or carbon tetrafluoride to open the window 6B. Next, the photosensitive resin layer 5 is completely removed using an etching solution that corrodes only the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed from the window 6B (step (c)). .
Further, the second conductor layer 7 is formed by using a known photolithography technique, and the electrical connection with the first conductor layer 3 is completely performed (step (d)). When a multilayer wiring structure having three or more layers is formed, each layer can be formed by repeating the above steps.

Next, the surface protective film layer 8 is formed. In this example, this surface protective film layer was coated with the polymer solution or resin composition of the present invention by a spin coat method and dried, and light was irradiated from above a mask on which a pattern for forming a window 6C was formed at a predetermined portion. Thereafter, development is performed with an alkaline aqueous solution to form a pattern, followed by heating to obtain a heat resistant polymer film. This heat-resistant polymer film protects the conductor layer from external stress, α rays, etc., and the obtained semiconductor device is excellent in reliability. In the above example, the interlayer insulating film layer can be formed using the polymer solution or the resin composition of the present invention.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples. Unless otherwise stated, all chemicals used were reagents. “%” Means “% by mass” unless otherwise specified. Moreover, the physical property etc. of the compound in an Example and a comparative example were measured with the following method.

<Measurement method of weight average molecular weight (Mw)>
The weight average molecular weights of the polyimide precursor and the polybenzoxazole precursor are determined by standard polystyrene conversion using a gel permeation chromatography method (GPC, apparatus is manufactured by Hitachi, Ltd., column is gel pack manufactured by Hitachi Chemical Co., Ltd.). It was. Specifically, the weight average molecular weight of each polymer was measured by GPC with the following apparatus and conditions.

Measuring device: Detector L4000UV manufactured by Hitachi, Ltd.
Pump: Hitachi Ltd. L6000
C-R4A Chromatopac manufactured by Shimadzu Corporation
Measurement conditions: Column Gelpack GL-S300MDT-5 × 2 eluent: THF / DMF = 1/1 (volume ratio)
LiBr (0.03 mol / l), H ₃ PO ₄ (0.06 mol / l)
Flow rate: 1.0 ml / min, detector: UV 270 nm
It measured using 1 ml of solvent [THF / DMF = 1/1 (volume ratio)] with respect to 0.5 mg of polymers.

<Measurement method of NMP content in polymer solution>
The polymer solution as a sample was diluted 10-fold with DMF (N, N-dimethylformamide), and then 1.0 μl was injected into a gas chromatography (GC) apparatus to analyze the NMP content.
A calibration curve was created from the NMP peak areas of standard solutions with NMP concentrations of 0.02%, 0.2%, and 2% prepared by diluting NMP manufactured by Wako Pure Chemical Industries with DMF, and the content of NMP from the peak area of the sample. The amount was determined.
Specifically, NMP content was measured by GC with the following apparatus and conditions.

Device: GL Science GC-4000
Carrier gas: 5.0ml / min
Column: TC-5
Injection temperature: 250 ° C
Detector temperature: 250 ° C
Oven temperature: 100 ° C. (3 min) → 10 ° C./min→250° C.

<Measurement method of chloride ion content in polymer solution>
The polymer solution was diluted 1 to 1000 times with ion-exchanged water, and 2 ml was injected into ion chromatography (Dionex 2010I-6), and the content of chloride ions was analyzed. A calibration curve is prepared from the Cl peak height of a standard solution for chloride ion concentration 5 ppm and 50 ppm prepared by diluting a standard reagent for ion chromatography (1000 ppm, manufactured by Wako Pure Chemical Industries, Ltd.), and chloride is obtained from the peak height of the sample. The ion content was determined.

<Measurement method of viscosity change rate>
Viscosity change rate was calculated | required from the following formula from the viscosity immediately after manufacture (initial viscosity) and the viscosity after storing for 2 weeks in a thermostat (23 degreeC).
Viscosity change rate (%) = (viscosity after storage for 2 weeks ÷ initial viscosity) × 100
The viscosity was measured with the following apparatus and conditions.

Measuring device: E-type viscometer (VISIONIC EHD, Toki Sangyo Co., Ltd.)
Measurement temperature: 25 ° C
Rotation speed: 2.5-20rpm

<Synthesis of polymer mixture>
The synthesis step for obtaining the polymer mixture which is the step (a) of the present invention was performed as follows.
Synthesis Example 1 [Synthesis of polyimide precursor solution (polymer mixed solution A)]
In a 0.2 liter flask equipped with a stirrer and a thermometer, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride (bis (3,4-dicarboxyphenyl) ether dianhydride: ODPA)) 9.9 g (32 mmol) and isopropyl alcohol 3.9 g (65 mmol) were dissolved in 45 g of N-methylpyrrolidone. Thereafter, a catalytic amount of 1,8-diazabicycloundecene was added, followed by heating at 60 ° C. for 2 hours. Subsequently, the mixture was stirred at room temperature (25 ° C.) for 15 hours for esterification. Thereafter, 7.6 g (64 mmol) of thionyl chloride was added under ice-cooling, and the mixture was returned to room temperature and reacted for 2 hours to obtain a carboxylic acid chloride solution (hereinafter, this solution is referred to as carboxylic acid chloride solution A).

Next, 40 g of N-methylpyrrolidone was charged into a 0.5 liter flask equipped with a stirrer and a thermometer, and 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1, After adding 3.3 g (28 mmol) of 3,3,3-hexafluoropropane and 0.4 g (4 mmol) of p-aminophenol and stirring and dissolving, the previously prepared carvone was maintained while maintaining the temperature at 0 to 5 ° C. The acid chloride solution A was added dropwise over 30 minutes, followed by stirring for 3 hours to obtain a polymer mixture A.

Synthesis Example 2 [Synthesis of polybenzoxazole precursor solution (polymer mixed solution B)]
In a 0.5 liter flask equipped with a stirrer and a thermometer, 15.5 g (60 mmol) of 4,4′-diphenyl ether dicarboxylic acid and 90 g of N-methylpyrrolidone were charged, and the flask was cooled to 5 ° C. Thereafter, 14.3 g (120 mmol) of thionyl chloride was added dropwise and reacted for 30 minutes to obtain a solution of 4,4′-diphenyl ether dicarboxylic acid dichloride.

Next, 88 g of N-methylpyrrolidone was charged into a 1 liter flask equipped with a stirrer and a thermometer, and 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3 was charged. , 3-hexafluoropropane (18.3 g, 50 mmol) and p-aminophenol (2.2 g, 20 mmol) were added, and the mixture was stirred and dissolved. Thereafter, while maintaining the temperature at 0 to 5 ° C., a solution of 4,4′-diphenyl ether dicarboxylic acid dichloride was added dropwise over 30 minutes and stirred for 3 hours to obtain a polymer mixture B.

Synthesis Example 3 [Synthesis of Polybenzoxazole Precursor (Polymer Mixture C)]
A polymer mixture C was obtained in the same manner as in Synthesis Example 2 except that dodecanedioic acid was used instead of diphenyl ether dicarboxylic acid.

Synthesis Example 4 [Synthesis of Polybenzoxazole Precursor Solution (Polymer Mixture D)]
In a 0.2 liter flask equipped with a stirrer and a thermometer, 12.9 g (50 mmol) of 4,4′-diphenyl ether dicarboxylic acid and 13.5 g (100 mmol) of 1-hydroxybenzotriazole were added to N-methyl- Dissolved in 75 g of 2-pyrrolidone. To this, 20.6 g (100 mmol) of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride dissolved in 25 g of N-methyl-2-pyrrolidone was cooled to a temperature of 0 to 5 ° C. It was dripped. After completion of the dropwise addition, the temperature of the reaction system was returned to room temperature and stirred as it was for 24 hours. After completion of the reaction, the precipitated dicyclohexylcarbodiurea was removed by filtration, 100 g of ion-exchanged water was added dropwise to the filtrate, and the precipitate was collected by filtration and dried in vacuo. This is called carboxylic acid derivative A.

To 90 g of N-methyl-2-pyrrolidone, 12.8 g (35 mmol) of 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane and p- 1.5 g (14 mmol) of aminophenol was dissolved, and further 20.7 g (42 mmol) of the dicarboxylic acid derivative A was added and dissolved by stirring. Thereafter, the reaction system was brought to 75 ° C. and stirred for 12 hours to obtain a polymer mixture D.

<Manufacture of polymer solution>
Example 1
(1) Step (b): Separation step To 100 g of the polymer mixture A synthesized in Synthesis Example 1, 100 g of ethyl acetate and 100 g of ion-exchanged water are added as a low boiling point solvent, and the separation is performed using a separatory funnel. went. After shaking the separating funnel several times, it was placed gently, and the aqueous layer was removed when it was divided into a low boiling point solvent layer and an aqueous layer.
Ion exchange water was further added to the separating funnel in which the low boiling point solvent layer remained, and a liquid separation operation was performed to remove the aqueous layer. The liquid separation operation for adding the ion-exchanged water and removing the aqueous layer was performed 5 times.
(2) Steps (c) and (d)
To the obtained low boiling point solvent layer, 40 g of γ-butyrolactone (GBL) and 10 g of dimethyl sulfoxide (DMSO) were added and mixed. Thereafter, the low boiling point solvent layer containing GBL and DMSO is concentrated under reduced pressure to remove ethyl acetate, and the polymer solution 1 is concentrated or diluted with GBL so that the volatile concentration in the polymer solution is about 65%. Obtained.
The expected amount of polymer precursor was calculated from the charged amount of raw materials such as polymer precursor monomers, and used as a non-volatile component (other than GBL and DMSO). The concentration of volatile components in the polymer solution was determined by quantitatively determining the volatile components (GBL and DMSO) by gas chromatography.

The weight average molecular weight, NMP content, chloride ion content, and viscosity change rate of the polymer solution 1 were determined by the measurement method described above. The weight average molecular weight of the polymer solution 1 was 12,760, the NMP content was 0.04%, the chloride ion content was 0.06%, and the viscosity change rate was 1.08%. The results are shown in Table 1.

Example 2
Separation was carried out in the same manner as in Example 1, except that ion-exchanged water (120 g) and methyl isobutyl ketone (MIBK) (120 g) as a low boiling point solvent were added to the polymer mixture B (200 g) synthesized in Synthesis Example 2. A liquid process was performed.
GBL (60 g) and DMSO (12 g) were added to and mixed with the low boiling point solvent layer obtained by the liquid separation step in the same manner as in Example 1. Thereafter, MIBK was removed by concentrating the low-boiling solvent layer containing GBL and DMSO under reduced pressure, and the polymer solution 2 was obtained by concentrating or diluting with a GBL so that the volatile concentration in the polymer solution was 65%. .
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3
In the same manner as in Example 2, the polymer mixed solution B (200 g) was separated.
GBL (60 g) and N-ethylpyrrolidone (NEP) (12 g) were added to and mixed with the low boiling point solvent layer obtained by the liquid separation step. Thereafter, MIBK was removed by concentrating the low boiling point solvent layer containing GBL and NEP under reduced pressure, and the polymer solution 3 was obtained by concentration or dilution with GBL so that the volatile content in the polymer solution was 65%. .
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4
The liquid separation step was performed in the same manner as in Example 2 except that the polymer mixture C synthesized in Synthesis Example 3 was used instead of the polymer mixture B, and methyl-t-butyl ether was used instead of MIBK as the low boiling point solvent. went.
GBL and N-ethylpyrrolidone (NEP) were added to and mixed with the low boiling point solvent layer obtained by the liquid separation step. Thereafter, the low boiling point solvent layer containing GBL and NEP is concentrated under reduced pressure to remove methyl-t-butyl ether and concentrated or diluted with GBL so that the volatile concentration in the polymer solution becomes 65%. 4 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 5
A polymer solution 5 was obtained in the same manner as in Example 1 except that the polymer mixture A was changed to the polymer mixture D synthesized in Synthesis Example 4.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1
The polymer mixture A synthesized in Synthesis Example 1 was added to ion exchange water, and the precipitate was collected. The polyimide precursor (polyamic acid ester) was obtained by sufficiently washing with ion-exchanged water and drying under reduced pressure.
The recovered polyamic acid ester was dissolved in GBL so that the volatile concentration in the polymer solution was 65%, whereby a polymer solution 6 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2
The polymer mixture B synthesized in Synthesis Example 2 was added to ion-exchanged water, and the precipitate was collected. The polybenzoxazole precursor was obtained by thoroughly washing with ion-exchanged water and drying under reduced pressure.
The recovered polybenzoxazole precursor was dissolved in GBL so that the volatile concentration in the polymer solution was 65%, to obtain a polymer solution 7.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3
The polymer mixture C synthesized in Synthesis Example 3 was added to ion-exchanged water, and the precipitate was collected. After thoroughly washing with ion-exchanged water and drying under reduced pressure, a carboxyl group-terminated polybenzoxazole precursor was obtained.
The recovered polybenzoxazole precursor was dissolved in GBL so that the volatile concentration in the polymer solution was 65%, and a polymer solution 8 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 4
The polymer mixture D synthesized in Synthesis Example 4 was added to a solution of ion exchange water and isopropanol (ion exchange water / isopropanol = 3/1). The precipitate was collected, washed thoroughly with ion exchange water, and then dried under reduced pressure to obtain a polybenzoxazole precursor.
The recovered polybenzoxazole precursor was dissolved in GBL so that the volatile concentration in the polymer solution was 65%, and a polymer solution 9 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 5
In the same manner as in Example 1, the polymer mixture A was separated.
GBL was added to the separated organic layer and concentrated under reduced pressure to remove ethyl acetate, and concentrated or diluted with GBL so that the volatile concentration in the polymer solution was 65%. Thus, a polymer solution 10 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 6
Polymer mixture B was separated in the same manner as in Example 2.
GBL was added to the separated organic layer and concentrated under reduced pressure to remove MIBK, and concentrated or diluted with GBL so that the volatile concentration in the polymer solution was 65%, whereby a polymer solution 11 was obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 7
Polymer mixture C was separated in the same manner as in Example 4.
GBL is added to the separated organic layer and concentrated under reduced pressure to remove methyl-t-butyl ether. The polymer solution 12 is concentrated or diluted with GBL so that the volatile concentration in the polymer solution is 65%. Obtained.
The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 8
Polymer mixture D was separated in the same manner as in Example 5.
GBL was added to the separated organic layer and concentrated under reduced pressure to remove ethyl acetate, and concentrated or diluted with GBL so that the volatile concentration in the polymer solution was 65%, to obtain a polymer solution 13. The obtained polymer solution was evaluated in the same manner as in Example 1. The results are shown in Table 2.

From the above results, the polymer solution obtained by using the method of the present invention has NMP content and chloride ion content as compared with the polymer solution obtained by the reprecipitation operation as in Comparative Examples 1 to 4. It can be confirmed that the amount is low.
Moreover, it can confirm that the polymer solution excellent in viscosity stability is obtained by adding a polar solvent.
As mentioned above, the utilization field of a polyimide precursor or a polybenzoxazole precursor solution can be expected by utilizing the present invention.

The polymer solution and the resin composition of the present invention are suitable for forming a cured film that becomes a surface protective film or an interlayer insulating film of an electronic component or the like.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
All the contents of the Japanese application specification that is the basis of the priority of Paris in this application are incorporated herein.

Claims (10)

1. A method for producing a polymer solution, comprising the following steps (a) to (d):
   (A) A synthesis step in which an amine component and an acid component are reacted in a solvent containing N-methyl-2-pyrrolidone (NMP) to obtain a polymer mixture containing a polyimide precursor or a polybenzoxazole precursor. b) Separation step of adding water or an aqueous solution and a low boiling point solvent to the polymer mixed solution, and removing the aqueous layer by liquid separation operation to obtain a low boiling point solvent layer. (c) Substitution solvent in the low boiling point solvent layer And a step of adding a polar solvent (d) A concentration step of distilling off the low-boiling solvent under reduced pressure after the step (c)
2. The method for producing a polymer solution according to claim 1, wherein the polar solvent is one or more solvents selected from dimethyl sulfoxide, N-ethylpyrrolidone and dimethylformamide.
3. The polymer solution according to claim 1 or 2, wherein the low boiling point solvent is one or more solvents selected from isobutanol, ethyl acetate, butyl acetate, diethyl ether, methyl-t-butyl ether, methyl ethyl ketone, and methyl isobutyl ketone. Manufacturing method.
4. The method for producing a polymer solution according to any one of claims 1 to 3, wherein the substitution solvent is one or more solvents selected from γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether.
5. The method for producing a polymer solution according to any one of claims 1 to 4, wherein the polyimide precursor or the polybenzoxazole precursor has a structure represented by the following general formula (I) or (II).
   

   

   (In the general formula (I), X represents a tetravalent organic group, p represents an integer of 0 to 2, and W represents a divalent to tetravalent organic group. R ¹ and R ² are each independently hydrogen. An atom, an aliphatic group having 1 to 6 carbon atoms, or a group represented by the following general formula (Ia).
   

   

   (In general formula (Ia), R ³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 6.)
   

   

   (In general formula (II), U is a tetravalent organic group, and V is a divalent organic group.)
6. A polymer solution obtained by the method for producing a polymer solution according to any one of claims 1 to 5.
7. The polymer solution according to claim 6, wherein the content of the polar solvent is 1 to 20% by mass of the whole.
8. The polymer solution according to claim 6 or 7, wherein the content of nonvolatile components is 10 to 50% by mass of the whole.
9. A resin composition containing the polymer solution according to any one of claims 6 to 8.
10. Applying the polymer solution according to any one of claims 6 to 8 or the resin composition according to claim 9 on a substrate and drying to obtain a resin film;
    And a step of heating the resin film.

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