JPS641494B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel polyimide resin and a method for producing the same. Conventionally, polyimide resins have excellent heat resistance as well as excellent electrical and mechanical properties, and have been widely used as industrial materials. However, many of these polyimide resins are insoluble in various organic solvents and mineral acids, and are also thermally infusible, making it extremely difficult to mold them. Therefore, the present inventors have made earnest efforts to produce polyimide resins that are soluble in various organic solvents and mineral acids, and have completed the present invention. The first invention of the present invention is based on the general formula (In the formula, R is a tetravalent organic group, Ar is a divalent tetraphenylthiophene group when there is only one type of Ar, Ar
When there are two or more types, one of them is a divalent tetraphenylthiophene group, the other is a divalent aromatic group, and n is an integer from 10 to 200). be. The second invention of the present invention is the general formula (In the formula, R is a tetravalent organic group, Ar is a divalent tetraphenylthiophene group when there is only one type of Ar, Ar
When there are two or more types, one of them is a divalent tetraphenylthiophene group, the other is a divalent aromatic group, and n is an integer of 10 to 200). During production, the general formula H ₂ N―Ar―NH ₂ () (in the formula, Ar is a divalent tetraphenylthiophene group when there is one type of Ar, and when there are two or more types of Ar, it is a divalent tetraphenylthiophene group). one type or two or more diamines represented by a divalent tetraphenylthiophene group as one type and a divalent aromatic group as the other type, and the general formula This is a method for producing a polyimide resin in which a tetracarboxylic dianhydride represented by the formula (wherein R represents a tetravalent organic group) is reacted in an organic solvent. The polyimide resin represented by the general formula () of the present invention has the characteristic that it can be obtained as an organic solvent solution by the production method of the present invention, and molded products such as polyimide resin films can be easily obtained from this solution. , its industrial value is extremely high. The polyimide resin represented by the above general formula () is produced from the diamine represented by the above general formula () and the tetracarboxylic dianhydride represented by the above general formula (). Diamines consisting of ruthiophene groups can be used alone, or
50 to 1 mol% of one or more diamines consisting of 99 mol% of tetraphenylthiophene groups
It is also possible to use a mixture of diamines consisting of aromatic groups. When using a mixture of diamines, if the diamine consisting of divalent tetraphenylthiophene groups is less than 50 mol%, the solubility in organic solvents and mineral acids, which is a feature of the present invention, will not be sufficiently satisfied. Among the diamines represented by the above general formula (), the diamine consisting of a divalent tetraphenylthiophene group refers to 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene. It is known that this diamine can be produced from benzyl chloride and sulfur, which are industrially available at low cost. For example, W. Dilthey et al.
Prakt.Chem.) Volume 2, pages 151 and 257 (1938
It was published in 2013). Among the diamines represented by the above general formula (), the diamines consisting of a divalent aromatic group include:
Metaphenylene diamine, paraphenylene diamine, 3,3'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-methylene dianiline,
4,4'-methylene dianiline, 4,4'-ethylene dianiline, 4,4'-isopropylidene dianiline, 3,3'-oxydianiline, 4,4'-oxydianiline, 3,4' -Oxydianiline, 3,
3′-thiodianiline, 4,4′-thiodianiline,
3,3'-carbonyldianiline, 4,4'-carbonyldianiline, 3,3'-sulfonyldianiline, 4,4'-sulfonyldianiline, 1,4'-naphthalenediamine, 1,5-naphthalenediamine , 2,6-naphthalenediamine, and the like. Examples of the tetracarboxylic dianhydride derivative represented by the above general formula () used in the present invention include pyromellitic dianhydride, 2,3,6,7
- Naphthalene tetracarboxylic dianhydride, 3,
4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-
dicarboxyphenyl) sulfone dianhydride, 2,
Examples include 2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, etc. I can do it. A method for producing a polyimide resin represented by the above general formula () is to prepare a diamine compound represented by the above general formula () and a tetracarboxylic dianhydride derivative represented by the above general formula () in an organic solvent under substantially anhydrous conditions. The reaction is carried out by reacting at 0 to 100°C for several tens of minutes to several days, and then at 80° to 400°C for several tens of minutes to several days. In this method, the molecular weight of the polyimide resin represented by the general formula () is limited by the amount of the diamine compound represented by the general formula () and the tetracarboxylic dianhydride derivative represented by the general formula (), When these reaction components are used in equimolar amounts, a high molecular weight polyimide resin represented by the above general formula () can be produced. The reason why n is limited to an integer between 10 and 200 in the polyimide resin of general formula () is that if n is smaller than 10, the mechanical properties and heat resistance of the molded product formed into a film etc. will not be sufficient. This is because if it exceeds 200, the solubility in organic solvents and moldability will deteriorate. Organic solvents that can be used in this method include N,
Amide solvents such as N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, sulfur solvents such as dimethyl sulfoxide and tetramethylene sulfone, anisole, diphenyl ether, nitrobenzene, benzonitrile, cresol, phenol. Examples include benzene-based solvents such as . In particular, when using a solvent that can azeotrope with water, such as cresol or nitrobenzene, the latter stage of the reaction can be carried out at the boiling point of these solvents, and if the solvent is removed at the same time by distillation, even higher efficiency can be achieved. The reaction can proceed. Further, at this time, by adding an additive such as isoquinoline, the solubility of the produced polyimide resin represented by the above general formula () in the organic solvent can be adjusted. In the present invention, a diamine compound represented by the above general formula () is reacted with a tetracarboxylic dianhydride derivative represented by the above general formula (), and the general formula (In the formula, R, Ar, and n are the same as in the general formula.) A polyimide acid derivative represented by Macromolecular Syntheses
Collective Volume Volume 1, Page 295 (1977
The polyimide resin of the present invention represented by the general formula () can also be produced by the method described in 2006). The polyamic acid derivative represented by the above general formula () is produced by reacting the diamine compound represented by the above general formula () with the tetracarboxylic dianhydride derivative represented by the above general formula () under substantially anhydrous conditions. It can be easily obtained by The degree of polymerization of the polyamic acid derivative represented by the above general formula () is limited by the amount of the diamine compound represented by the above general formula () and the tetracarboxylic dianhydride derivative represented by the above general formula (). When these reaction components are used in equimolar amounts, a high molecular weight polyamic acid derivative represented by the above general formula () can be produced. The molecular weight of this polyamic acid derivative is the same as that of the polyimide resin of general formula (). The reaction temperature that can be used to produce the polyamic acid derivative represented by the above general formula () can be selected between 0°C and 300°C, but the reactants at high temperatures will form a polyimide structure that has undergone further reaction. It is preferable to control the reaction temperature to 60°C or less. Examples of organic solvents that can be used in this reaction include the same solvents as used in the above-mentioned case in which the polyimide resin is produced without using the polyamic acid derivative represented by the general formula (). One method for cyclizing the thus obtained polyamic acid derivative represented by the above general formula () into a polyimide resin represented by the above general formula () is to cyclize the polyamic acid derivative represented by the above general formula () at 50°C. This method involves heating to a temperature within the range of ~500°C. This heating time varies depending on the heating temperature within the above range, but is generally between several seconds and several tens of hours. Alternatively, a polyamic acid derivative represented by the above general formula () can be easily converted into a polyimide resin by chemically treating it with an acid anhydride such as acetic acid, propionic acid, butyric acid, or benzoic acid. Cyclization can be achieved. Here, it is desirable to use pyridine or the like together with the carboxylic acid anhydride as a substance that promotes the cyclization reaction. As an alternative method for producing the polyimide resin represented by the above general formula (), the reaction proceeds by the same method as the method for producing the polyamic acid derivative represented by the above general formula (), and in the latter stage, the above-mentioned general formula Additives such as acetic anhydride are added to the polyamic acid derivative represented by the formula () without isolating it, and the mixture is further reacted at a temperature of 0° C. to 300° C. for several minutes to several tens of hours. As additives that can be used in this reaction, it is possible to use the same additives used when producing the polyimide resin represented by the general formula () by chemically treating the polyamic acid derivative represented by the general formula (). can. The thus produced polyimide resin represented by the general formula () depends on the manufacturing method used, the diamine represented by the general formula () used, and the type of tetracarboxylic dianhydride derivative represented by the general formula () used. In particular, its solubility varies, but many derivatives are soluble in mineral acids such as sulfuric acid. In addition, some derivatives include chloroform, tetrachloroethane, N,N-dimethylformamide, N,N-dimethylacetamide, N-
It becomes soluble in all or part of solvents such as methyl-2-pyrrolidone, dimethyl sulfoxide, and cresol. The polyimide resin represented by the above general formula () is thermally stable and shows no noticeable change even when heated to around 500°C. The present invention will be explained in more detail below with reference to Examples. Example 1 418 mg (1 mmol) of 2.5-di(4-aminophenyl)-3,4-diphenylthiophene in 5 ml
was dissolved in dehydrated m-cresol and heated to 40°C under a nitrogen stream. To this solution was added 322 mg (1 mmol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride, and 2.4 ml of dehydrated m-
A small amount of remaining tetracarboxylic dianhydride was washed away with cresol and added to the reaction solution. The reaction was carried out with stirring at 45°C for 3 hours and at 150°C for 3 hours. A distillation head and a Liebig condenser were attached to the reaction apparatus, and the solvent m-cresol was distilled under a nitrogen stream at an oil bath temperature of 250°C. At this time, dehydrated m-cresol was added so that the liquid volume in the reactor was maintained at about 7 ml. After performing this operation for 5 hours, the mixture was cooled to room temperature under a nitrogen stream to obtain a yellow polyimide resin solution. This solution was poured into 300 ml of methanol to obtain a polyimide resin precipitate, which was dried under reduced pressure at 100° C. for 4 hours. On the other hand, the m-cresol solution at the end of the reaction was cast on a glass plate to obtain a polyimide film. The intrinsic viscosity of the resulting resin was 0.58 (0.5 g/dl, m-cresol at 30°C). Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 Elemental analysis value C H N S Calculated value (%) 76.70 3.41 3.98 4.55 Actual value (%) 76.02 3.36 3.64 4.51 Organic solvent of the produced polyimide resin and Solubility in sulfuric acid is shown in the table. Example 2 418 mg (1 mmol) of 2.5-di(4-aminophenyl)-3,4-diphenylthiophene and 42 mg of isoquinoline were dissolved in 5 ml of dehydrated m-cresol and heated to 40°C under a nitrogen stream. In this solution
Add 322 mg (1 mmol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride to 2.4
A small amount of remaining tetracarboxylic dianhydride was washed away with ml of dehydrated m-cresol and added to the reaction solution. The reaction was carried out at 45°C for 3 hours and at 150°C for 3 hours with stirring. A distillation head and a Liebig condenser were attached to the reaction apparatus, and the solvent was distilled under a nitrogen stream at an oil bath temperature of 250°C. At this time, dehydrated m-cresol containing 25 mg/ml of isoquinoline was added so that the liquid volume in the reactor was maintained at about 7 ml. After performing this operation for 5 hours, the mixture was cooled to room temperature under a nitrogen stream to obtain a yellow polyimide resin solution. Pour this solution into 300ml of methanol to obtain a precipitate of polyimide resin.
It was dried under reduced pressure at 100°C for 4 hours. On the other hand, the m-cresol solution at the end of the reaction was cast on a glass plate to obtain a polyimide film. The intrinsic viscosity of the resulting resin was 0.61 g/dl (m-cresol, 30°C). Infrared absorption spectrum (film) cm ⁻ ; 1780, 1720, 1360, 720 The solubility of the produced polyimide resin in organic solvents and sulfuric acid is shown in Table 1. Example 3 418 mg (1 mmol) of 2.5-di(4-aminophenyl)-3,4-diphenylthiophene in 5 ml
was dissolved in dehydrated N-methyl-2-pyrrolidone (NMP). To this solution was added 322 mg (1 mmol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride under a nitrogen stream, and 2.4 ml of
A small amount of remaining tetracarboxylic dianhydride was washed away with dehydrated NMP and added to the reaction solution. at 15℃
The reaction was carried out for 1.5 hours and at 25° C. for 1.5 hours under a nitrogen stream. 4 mmol of pyridine and 4 mmol of acetic anhydride were added to the resulting yellow solution, and the mixture was stirred at 25°C for 24 hours.
This solution was poured into 300 ml of methanol to obtain a polyimide resin precipitate, which was dried under reduced pressure at 100° C. for 4 hours. The intrinsic viscosity of the produced resin is 0.82 (0.5g/dl,
H ₂ SO ₄ , 30°C). Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 Table 1 shows the solubility of the produced polyimide resin in organic solvents and sulfuric acid. Example 4 418 mg (1 mmol) of 2.5-di(4-aminophenyl)-3,4-diphenylthiophene in 5 ml
was dissolved in dehydrated N,N-dimethylacetamide (DMAc). To this solution was added 322 mg (1 mmol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride under a nitrogen stream.
A small amount of remaining tetracarboxylic dianhydride was washed away with 1 ml of dehydrated DMAc and added to the reaction solution. 15
The mixture was stirred at 25°C for 1.5 hours and at 25°C for 24 hours under a nitrogen stream.
The obtained solution was poured into 300 ml of methanol to obtain a precipitate of polyamic acid. [Intrinsic viscosity 0.58 (0.5
g/dl, DMAc, 30°C)] On the other hand, the solution at the end of the reaction was cast on a glass plate and dried in air at 80°C to obtain a polyamic acid film. The obtained film was mixed with 30 ml of benzene, 10 ml of pyridine, and 10 ml of acetic anhydride.
Soaked in a mixture of for 24 hours. Further under nitrogen flow
A polyimide film was obtained by heat treatment at 300°C for 1 hour. On the other hand, polyamic acid film was heated at 200℃ for 5 hours.
A polyimide film was obtained by heat treatment at 300° C. for 1 hour under a nitrogen stream. Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 The produced polyimide film was soluble in sulfuric acid, but insoluble in organic solvents. Example 5 Polyamic acid [specific particle size 0.99 (0.5 g/ dl,
DMAc, 30°C)] and a polyimide film was obtained in the same manner as in Example 4. Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 The produced polyimide film was soluble in sulfuric acid, but insoluble in organic solvents. Example 6 2.5-di(4-aminophenyl)-3,4-diphenylthiophene was prepared in the same manner as in Example 1.
A copolyimide resin was obtained from 0.9 mmol of 4,4'-oxydialinine and 1 mmol of 3,4,3',4'-benzophenonetetracarboxylic dianhydride. The intrinsic viscosity of the produced resin is 0.99 (0.5g/dl,
H ₂ SO ₄ , 30°C). Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 The solubility of the produced copolyimide resin in organic solvents and sulfuric acid is shown in Table 1. Example 7 2.5-di(4-aminophenyl)-3,4-diphenylthiophene was prepared in the same manner as in Example 1.
A copolyimide resin was obtained from 0.8 mmol of 4,4'-oxydianiline and 1 mmol of 3,4,3',4'-benzophenonetetracarboxylic dianhydride. The intrinsic viscosity of the resulting resin is 1.06 (0.5g/dl,
H ₂ SO ₄ , 30°C). Infrared absorption spectrum (film) cm ^-1 ; 1780, 1720, 1360, 720 The solubility of the produced copolyimide resin in organic solvents and sulfuric acid is shown in Table 1.

[Table] ;Soluble at room temperature +;Soluble at heat ±;Partially soluble
-: insoluble The present invention provides a polyimide resin represented by the general formula () and an advantageous method for producing this polyimide resin. Most conventional polyimide resins are insoluble and infusible in both organic solvents and mineral acids, making it extremely difficult to mold them, whereas the polyimide resin of the present invention is resistant to organic solvents and/or mineral acids. It is soluble, easy to mold, and has excellent heat resistance, electrical properties, and mechanical properties, so it has great value as an industrial material.

Claims (1)

[Claims] 1. General formula (In the formula, R is a tetravalent organic group, Ar is a divalent tetraphenylthiophene group when there is only one type of Ar, Ar
When there are two or more types, one of them is a divalent tetraphenylthiophene group, the other type is a divalent aromatic group, and n is an integer of 10 to 200. 2 General formula (In the formula, R is a tetravalent organic group, Ar is a divalent tetraphenylthiophene group when there is only one type of Ar, Ar
When there are two or more types, one of them is a divalent tetraphenylthiophene group, the other is a divalent aromatic group, and n is an integer of 10 to 200). During production, the general formula H ₂ N-Ar-NH ₂ (wherein, Ar is a divalent tetraphenylthiophene group when there is one type of Ar, and one of them when there are two or more types of Ar) One or more diamines represented by a divalent tetraphenylthiophene group as a species and a divalent aromatic group as another species, and the general formula A method for producing a polyimide resin, which comprises reacting a tetracarboxylic dianhydride represented by the formula (wherein R represents a tetravalent organic group) in an organic solvent.