JPS58104925A - Polyamide-imide resin composition and its preparation - Google Patents

Abstract

PURPOSE:To obtain the titled resin composition having improved resistance to heat softening, by reacting a polycarboxylic acid containing citric acid with a diisocyanate and a lactam. CONSTITUTION:A resin composition obtained by reacting a polycarboxylic acid containing 10mol% or more citric acid and/or a derivative thereof, preferably an aromatic tricarboxylic acid, particularly trimellitic acid, with a diisocyanate and/or a derivative thereof, preferably an aromatic diisocyanate and/or the aromatic diisocyanate masked with a phenol, particularly 4,4'-diphenylmethane diisocyanate, and a lactam, e.g. epsilon-caprolactam, in a phenolic solvent, and adding 5-150pts.wt., expressed in terms of polyisocyanate based on 100pts.wt. resultant resin content in the reaction product, polyisocyanate compound masked with a phenol to the reaction product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polyamideimide resin composition and a method for producing the same.

Organic insulating materials used in electrical equipment include phenol resins, polyvinyl formal resins,
Polyester resins, alkyd resins, epoxy resins, polyesterimide resins, polyamideimide resins, % polyimide resins, etc. are commonly used.

In recent years, with the need for resource and energy conservation and the miniaturization and weight reduction of peripheral equipment, the high performance and miniaturization of electrical equipment itself has been progressing. The importance of materials is increasing.

In the field of insulating paints, polyester resin paints have been widely used in recent years due to their relatively practical balance of heat resistance, mechanical properties, electrical properties, and economic efficiency. The use of imide group-containing resin coatings such as polyesterimide, polyamideimide, and polyimide is increasing.

Among imide group-containing resins, polyamide-imide resin is known to have the best balance of heat resistance, mechanical properties, electrical properties, and chemical properties.

However, conventional aromatic polyamide-imide resins only dissolve in expensive organic polar solvents such as N-methyl-2-pyrrolidone and dimethylacetamide. there were.

1.1 Furthermore, since organic polar solvents have strong hygroscopic properties, paints using them as solvents also have the disadvantage of being difficult to manage during storage and use.

For this reason, in the field of insulated wires, insulated wires and polyester imide resin paints are used, which sacrifice heat resistance and are soluble in relatively inexpensive phenolic solvents such as phenol, cresol, and xylenol. Double-coated wires, in which the lower layer is coated and baked with polyamide-imide resin paint on the upper layer, are now mainly used, but insulated wires using polyamide-imide resin paint do not have a good balance of characteristics. Therefore, it has not yet reached the point where it satisfies the various requirements of current electrical equipment.

Therefore, many proposals have been made for polyamide resins that are partially aliphatic modified and have excellent solubility in organic solvents by using amino acids, lactams, etc. as raw materials (for example, Japanese Patent Publication No. 56-17374, Japanese Patent Publication No. 56-2233).
), Special Publication No. 56-34210).

However, when aliphatic modification is performed in which a methylene chain is introduced into the molecule, as is the case with lactam, the heat resistance, especially the heat softening temperature when used as an insulated wire, is inferior to that of aromatic polyamide-imide resin. The reality is that a resin with a comprehensive balance has not yet emerged.

As a result of intensive research into polyamide-imide resin compositions with excellent solubility, the inventors of the present invention have discovered that by using citric acid, which has rarely been considered as a material for heat-resistant resins, They discovered that it was possible to obtain a polyamide-imide resin composition that had better heat softening properties than polyamide-imide resins and also had significantly improved solubility in organic solvents, and filed a patent application.

However, when we further investigated polyamide-imide resin compositions containing citric acid, we found that at least 1 citric acid was added to the polyamide-imide resin composition.
It has been found that when a polycarboxylic acid containing 0 mol% or more is used, a polyamide-imide resin composition can be obtained in which the resin concentration can be increased without substantially reducing the heat resistance even when a lactam is used in combination.

The present invention was made based on this knowledge, and includes a polyamide-imide resin composition characterized by reacting a polycarboxylic acid containing citric acid and/or its derivative with a lactam, and a mask using phenols. The present invention aims to provide a polyamide-imide resin composition characterized in that it contains a polyisocyanate compound as described above, and a method for producing the same.

The citric acid used in the present invention can be used with or without water of crystallization, but since the reaction with diamine involves dehydration, from the viewpoint of reaction efficiency, citric acid with no water of crystallization can be used. It is preferable to use acids.

Polycarboxylic acids and/or their derivatives other than citric acid include tricarboxylic acids, tetracarboxylic acids, dicarboxylic acids and/or their derivatives. ) Aromatic tricarboxylic acids, aromatic tricarboxylic acid esters, aromatic tricarboxylic acid anhydrides, etc. shown in (1) are used alone or in a heated state.

1:, 1+1 CI) (u) where R,=
H, alkyl group, phenyl group Generally, trimellitic anhydride is preferred due to its heat resistance, high reactivity, economical efficiency, etc.

In addition, it is desirable to use tetracarboxylic acids in combination for the purpose of increasing the imide bond ratio and further increasing heat resistance. Examples of these tetracarboxylic acids include pyromellitic acid, 3.
3',4,4'-benzophenonetetracarboxylic acid, butanetetracarboxylic acid, 3゜3',4,4'-diphe-:-nyltetracarboxylic acid, 2.2'.

::: 3.3'-Diphetritetracarboxylic acid, bicyclo[2
・2.2]-Oct-(7)-ene-2:3.5:6 tetracarboxylic acid, 3,3',4,4'-Schiff, nylethertetracarboxylic acid, 2.2',3. 3'-diphenyl ether tetracarboxylic acid, 1,4,5.8-
Naphthalenetetracarboxylic acid, 2,3,6.7-naphthalenetetracarboxylic acid, 1,2.5.6-naphthalenetetracarboxylic acid, 2,2-bis-(3゜4-dicarboxyphenyl)propane, bis- Examples include (3,4-dicarboxyphenyl)sulfone, 2°5-bis(3,4-dicarboxyphenyl)1°3.4 oxadiazole, and derivatives such as anhydrides and esters thereof.

Among these, pyromellitic anhydride, 3.3', 4゜4
'-benzophenonetetracarboxylic anhydride, butanetetracarboxylic acid, and 3.3',4.4'-diphenyltetracarboxylic acid anhydride are more preferred in view of heat resistance, solubility, and economical efficiency.

Examples of dicarboxylic acids among polycarboxylic acids include aromatic or aliphatic dicarboxylic acids such as terephthalic acid, isophthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, and azelaic acid. There are basic acids or their derivatives.

Examples of suitable lactams that can be used in combination with polycarboxylic acids in the present invention include ε-caprolactam, γ-butyrolactam,
--parerolactam, ω-laurinlactam, etc.

ε-caprolactam is preferable in terms of solubility, reactivity, and economical efficiency.

Citric acid and aromatic tricarboxylic acid and/or its derivatives occupy at least 10% in the polycarboxylic acid and/or its derivatives in terms of solubility in organic solvents and heat resistance.
Aromatic tricarboxylic acids containing mol% citric acid and/or
It is desirable to contain 20 mol % or more of the compound or its derivative.

The mol% of the citric acid and aromatic tricarboxylic acid and/or its derivatives represents the percentage based on the total polycarboxylic acid (the same applies hereinafter).

If the aromatic tricarboxylic acid and/or its derivative is less than 20 mol% and the citric acid is less than 10 mol%, the solubility in phenolic solvents and heat resistance will decrease, making it difficult to obtain a practical resin composition. Can not.

The proportion of the lactam used in combination with the polycarboxylic acid and/or its derivative is preferably the same as or less than the mole percent of the tricarboxylic acid and/or its derivative, and is preferably 10 mole % or more based on the total polycarboxylic acid.

If the lactam ratio is less than 10 mol%, a highly concentrated resin solution cannot be obtained, and if it exceeds the mol% of tricarboxylic acid and/or its derivatives, the heat resistance, especially the heat softening temperature, will decrease. Undesirable.

The diisocyanate and/or its derivative used in the present invention may be any aliphatic, alicyclic, or aromatic diisocyanate and/or its derivative.

Examples of such diisocyanates include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, heptamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, and trimethyl diisocyanate. Aliphatic and alicyclic compounds such as xamethylene diisocyanate, morpholine diisocyanate, cyclohexane diisocyanate), 3.9-bis(3-propyl isocyanate) 2,4,8.10-tetraoxaspiro[5.5]undecane, etc. Group diisocyanates, 4.4'-diphenylmethane diisocyanate, 4.4'-diphenyl ether diisocyanate, 4
．． 4'-diphenylbroban diisocyanate), 4.4
'-Diphenylsulfone diisocyanate, 3.3'-
diphenylsulfone diisocyanate, 4.4'-diphenylsulfite diisocyanate, 3.3'-dimethyl-4°4'-diphenylmethane diisocyanate,
3.3'-dichloro-4,4'-diphenylmethane diisocyanate, 3.3'-dimethyl-4,4'-bisphenyl diisocyanate, 3.3'-dimethoxyV-4°:,,1 4'-bisphenyl Diisocyanate, 4.4'- and sphenyl diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 2.4-
) There are aromatic diisocyanates such as lylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, and p-xylylene diisocyanate, which can be used alone or in combination.

Further, diisocyanate derivatives in which the isocyanate groups of diisocyanate are masked with phenols such as phenol, cresol, and xylenol can also be used.

Part of the diisocyanate and/or its derivative 4
, 4', 4'-triisocyanate-triphenylmethane, 2.2', 5,5'-tetraisocyanate-4
, 4'-dimethyldiphenylmethane and the like can also be substituted with trivalent or higher polyisocyanates.

Among these isocyanate compounds, 4°4'-Schiff, nylmethane diisocyanate, 2,4-tolylene diisocyanate, 2.6-)lylene diisocyanate, considering heat resistance, mechanical properties of the insulating film, and economical efficiency. It is particularly preferable to use m-xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, etc. alone or in combination.

The temperature and time for the reaction of polycarboxylic acids including citric acid and/or their derivatives with diisocyanates and/or their derivatives and lactams vary depending on the starting materials and the type of reaction, solution reaction or solvent-free reaction, but in general The reaction temperature is 60 to 350°C and the reaction time is from several hours to several tens of hours.

In the case of a solution reaction, it is affected by many factors such as the solvent used, the solid content when charging the starting materials, and the presence or absence of a catalyst, but the decarboxylation reaction between polycarboxylic acid or its derivative, lactam, and diisocyanate is approximately 70% Starting from around ℃,
Further, in consideration of the boiling point range of solvents that can generally be used in this reaction, the preferred temperature range is 70 to 250°C.

If the reaction time is extremely long, the isocyanate group and the solvent,
Since side reactions such as reactions between isocyanate groups occur, this is not preferable, and the preferred time is several hours to 30 hours.

The present invention can be carried out without a solvent, and in that case, the reaction can generally be carried out at a lower temperature and in a shorter time than in a solvent reaction.

However, solution reaction is more preferable in consideration of conditions such as ease of obtaining the desired high polymer and how the resin composition is used.

As the solvent used in the solution reaction, many organic solvents can be used since the resin composition of the present invention has excellent solubility.

Suitable solvents for the present invention include phenol, 0-cresol, n-cresol, p-cresol, various xylenolic acids, various chlorophenols, nitrobenzene,
Examples include N-methyl-2-pyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, hexamethylphosphoramide, dimethylsulfoxide, etc., and these can be used in combination. Examples of solvents include benzene, toluene, xylene, and aromatic hydrocarbon ureas with high boiling points (for example, Maruzen 11 Petroleum Co., Ltd., Swazol $ 1000''', Miswazol 1
500, Nippon Oil Co., Ltd.'s Nippon Seki Heizol 100.8 Koku Hysol 150, etc.), Monomedel Acetate, etc.

The preferred solvent composition is the stability of the resulting resin solution,
It is a mixture of a phenolic solvent such as phenol, cresol, xylenol, etc. and a high boiling point aromatic hydrocarbon solvent from the viewpoint of film forming properties and economic efficiency.

There is no particular restriction on the solid content concentration during the reaction, but if it is less than 35%, the reaction will take a long time, side reactions will easily occur, and it will be difficult to obtain a highly polymerized resin composition, so it should be 35% or more. More preferred.

The reaction of the present invention can be promoted by a catalyst commonly used for the reaction of isocyanate compounds.

Examples of suitable catalysts include lead monoxide, boric acid, metal salts of naphthenic acids such as lead naphthenate, zinc naphthenate, phosphoric acid,
Polyphosphoric acid, organic titanium compounds such as tetrabutyl titanate and triethanolamine titanate, triethylamine, 1,8-diaza-vinchlo(5.4.0) undecene-7 (j::11. including this acid adduct), etc. There is.

The preferred amount used is 0.01 to 5% by weight based on the solid content at the time of preparation, and there are no particular restrictions on the order or method of addition.

The polycarboxylic acid containing citric acid and/or its derivative, the diisoleanate and/or its derivative, and the lactam may be charged at the same time from the start of the reaction. It can also be prepared separately, and there are no particular restrictions on the preparation method.

The reaction can be controlled by observing the bubbling of generated carbon dioxide and the degree of distillation of reaction water, as well as the viscosity of the solution.

Adding a phenol-masked polyisocyanate to the resin composition thus obtained is suitable as an insulating coating.

As the masked polyisocyanate, the compound used to obtain the polyamideimide resin composition can be used as is.

The amount used is 5 to 1 per 100 parts by weight of the resin content of the resin composition.
50 parts by weight is preferred.

If it is less than 5 parts by weight, the workability and heat softening resistance when obtaining an insulated wire will be poor, and if it exceeds 150 parts by weight, the wear resistance will be poor.

The resin composition of the present invention may be further blended with other resins as necessary.

Furthermore, a modified polyamide-imide resin composition can also be prepared by adding other functional compounds such as polyols, polyamines, and polycarboxylic acids and further reacting them.

The resin composition of the present invention exhibits extremely excellent solubility even in phenolic solvents due to the use of tricarboxylic acid and/or its derivatives, including citric acid as an essential component, and is only soluble in conventional organic polar solvents. Because it has better heat resistance than aromatic polyamide-imide resin, it can be used not only in the field of electrical insulation materials such as impregnated resins, laminates, films, and adhesives, but also in the fields of heat-resistant paints, fibers, and molded resins. It is applicable and extremely useful in practice.

The present invention will be explained below with reference to Examples.

Example 1 Citric anhydride 19.277 (0.1 mol) and trimellitic anhydride 76.811 (0.4 mol) were placed in a 314 Turow flask equipped with a temperature needle, stirrer, cooling tube, and nitrogen inlet tube.
and adipic acid 73.0,! ii' (0-5 mol) and C-caprolactam 56.517 (0.5 mol) and 4
．． 4'-diphenylmethane diisocyanate 250.3
9 (1,Q mol) and 350 g of m-cresol were charged and the temperature was raised to 200° C. over about 1 hour in a nitrogen stream.

Significant foaming was observed from around 70°C, and distilled water was observed from 160°C.

When the reaction was continued for 16 hours at the reflux temperature of cresol (200-210°C), a transparent and viscous resin solution was obtained.

Next, Cresol 350 Ii was added and thoroughly stirred to obtain a reddish brown transparent resin solution having a non-volatile content (200°C x 1.5H) of 34.8% and a viscosity (25°C) of 62 voids.

The resulting resin solution was baked on a 0.1 m thick copper plate at 200°C for 20 minutes and at 250°C for 30 minutes.The resulting coating film had sufficient flexibility, and its infrared absorption spectrum showed 1.
Imide group absorption was observed at 780 ugi-1, and amide group absorption was observed at 1650ffi''-'.

The properties of the insulated wire obtained by coating and baking the obtained resin solution on a 1.0 WO copper wire were as shown in the table.

Example 2 19.217 g (0.1 mol) of citric acid anhydride and 76.8 g (0.4 mol) of trimellitic anhydride were placed in a 314-turoh flask equipped with a thermometer, stirrer, cooling tube, and nitrogen inlet tube.
, 3,3', 4,4'-benzophenonetetracarboxylic anhydride 161.09 (0.5 mol), ε-caprolactam 56.5 g (0.5 mol), 4,4'-
Diaminodiphenyl meta/250.3 J? (1,
0 mol) and m-rtz sol (400 g) were charged, and the temperature was raised to 210°C over about 1 hour in a nitrogen stream.

Significant foaming was observed at around 70°C, and distilled water was observed at around 160°C.

The reaction was continued at 210°C for 6 hours, and then m-cresol 30
0 g, solvent naphtha (Maruzen Sekiyu Swasol 10
00) 180.9 was added and stirred thoroughly to reduce the non-volatile content (200℃ x 1.5H) to 35.0%, viscosity (25
℃) A reddish-brown transparent resin solution with 84 voids was obtained.

The resulting resin solution was baked on a 0.1 m thick copper plate at 200°C for 20 minutes and at 250°C for 30 minutes.The resulting coating film had sufficient flexibility, and its infrared absorption spectrum showed 1.
Imide group at 730m''1, 16501m-'4
Absorption of m amide group was observed in each case.

Further, the properties of an insulated wire obtained by coating and baking the obtained resin solution on a 1.05 m5zr copper wire were as shown in the table.

Example 3 Anhydrous citric acid 96.09 (0.5 mol) was placed in a 3-4 flask equipped with a thermometer, stirrer, cooling tube, and nitrogen inlet tube.
, trimellitic anhydride 76.81i (0.4 mol)
, butanetetracarboxylic acid 23.49 (0.1 mol)
, ε-caprolactam 45.2.9 (0.4 mol),
4,4'-diphenylmethane diisocyanate 25
0.3 fl (1,0 mol), m-cresol 350
9 was added thereto, and the temperature was raised to 210°C over about 1 hour in a nitrogen stream.

The reaction was continued at 210° C. for 10 hours while the generated carbon dioxide gas and distilled water were distilled off.

Next, m-cresol 250 F was added and thoroughly stirred to obtain a non-volatile content (250°C X i, 5 H) of 39.0%.
A reddish-brown transparent resin solution with a viscosity (25° C.) of 65 voids was obtained.

The resulting resin solution was baked on a 0.1B thick copper plate at 200°C for 20 minutes and then at 250°C for 30 minutes.The resulting coating film had sufficient flexibility, and its infrared absorption spectrum Imide group at 1780 cm, 1640-1680
Broad absorption of amide groups was observed toward C11-''.

Further, the properties of the insulated wire obtained by coating and baking the obtained resin solution on a 1.0-inch copper wire were as shown in the table.

Example 4 In a 314 Turow flask equipped with a thermometer, stirrer, cooling tube, and nitrogen inlet tube, 38.4 N (0.2 mol) of citric acid anhydride, 38.49 N (4.2 mol) of trimellitic anhydride,
Butanetetracarboxylic acid 117.0 N (0.5 mol), isophthalic acid 16.69 (0.1 mol), ε-caprolactam 22.69 (0.2 mol), 4,4'-
Diphenylmethane diisocyanate 275.0.9 (
1.1 mol) and m-cresol 35011 were charged, and the temperature was raised to 210°C over about 1 hour in a nitrogen stream.

The reaction was continued at 210° C. for 8 hours while the generated carbon dioxide gas and distilled water were distilled off.

Next, 250 g of m-cresol was added and thoroughly stirred to obtain a mixture with a non-volatile content (250°C x 1.5 H) of 39.5% and a viscosity (
A reddish-brown transparent resin solution with 70 voids (25° C.) was obtained.

The obtained resin solution was heated at 200°C on a 0.1 fl thick copper plate.
The coating film obtained by baking for 20 minutes at 250°C and 30 minutes at 250°C has sufficient flexibility, and its infrared absorption spectrum (2 is 1780 C1l-"l Niimide group, 1650 am
-” Absorption of the niamide group was observed in each case.

The properties of the insulated wire obtained by coating and baking the obtained resin solution on a 1.0 fi, 1 copper wire were as shown in Table ζ.

Example 5 Masked diisocyanate compound a4. obtained in Reference Example was added to 100 g of the resin solution obtained in Example 1. Add S# (50 parts by weight based on diisocyanate count) and heat at 80℃ for 30 minutes.
The mixture was stirred for a minute to ensure uniform dissolution.

The properties of the insulated wire obtained by coating and baking the obtained resin solution on a copper wire of 1.0 mm were as shown in the table.

Example 6 7 g (10 parts by weight in terms of diisocyanate) of the masked diisocyanate compound obtained in Reference Example was added to the resin solution ioo Ii obtained in Example 2, and the mixture was heated at 120°C for 30 minutes.
The mixture was stirred for a minute to ensure uniform dissolution.

The obtained resin solution was added to 1. The properties of the insulated wire obtained by coating and baking on a Qm$ copper wire were as shown in the table.

Example 7 Masked diisocyanate compound 94, s, 9 (obtained in Reference Example) was added to 100 g of the resin solution obtained in Example 4.
120 parts by weight (calculated as diisocyanate) and m-cresol 8077 were added and stirred at 60°C for 20 minutes to uniformly dissolve.

The resulting resin solution was coated and baked on a 1.0 w$ copper wire, and the characteristics of the rim wire were as shown in the table.

Reference example (manufacture of masked diisocyanate) 314 Tulo flask with temperature needle, stirrer, cooling tube, and nitrogen inlet tube = 4,4'-diphenylmethane diisocyanate 250
．． 3 Prepare 250.3g of # and m-cresol and 200g
The reaction was carried out at ℃ for 30 minutes.

When a portion of the contents was taken out and its infrared absorption spectrum was measured, no absorption of the isocyanate group of 22600IL-'' was observed, and the formation of a diisocyanate compound masked with m-cresol was confirmed.

After reacting for an additional 10 minutes, the mixture was cooled to room temperature to obtain a lumpy resin.

Margin below

Claims (1)

[Claims] 1. A polycarboxylic acid containing citric acid and/or a derivative thereof, and a diisocyanate and/or a derivative thereof;
A polyamide-imide resin composition characterized by reacting with a lactam. 2. Claim 1, wherein the polycarboxylic acid containing citric acid and/or its derivative is a polycarboxylic acid containing at least 10 mol% of an aromatic tricarboxylic acid containing citric acid and/or its derivative at 20 mol% or more. The polyamide-imide resin composition described in . 3. The polyamide-imide resin composition according to claim 1 or 2, wherein the aromatic tricarboxylic acid and/or its derivative is trimellitic anhydride. 4. Claim 1, wherein the diisocyanate and/or its derivative is an aromatic diisocyanate and/or an aromatic diisocyanate masked with a phenol.
The polyamide-imide resin composition according to any one of Items 1 to 3. 5. The polyamide-imide resin composition according to any one of claims 1 to 4, wherein the lactam is 8-caprolactam. 6. Aromatic tricarboxylic acid containing at least 10 mol% or more of citric acid and/or a polycarboxylic acid and/or its derivative containing 20 mol% or more of its derivative, an aromatic diisocyanate and/or its derivative, and a lactam. In the reaction product, a polyisoleanate compound masked with phenols is added in an amount of 5 to 150 parts by weight in terms of polyisocyanate per 100 parts by weight of the resin content of the reaction product.
A polyamide-imide resin composition comprising: 7. Aromatic tricarboxylic acid containing at least 10 mol% or more of citric acid and/or polycarboxylic acid and/or its derivative containing 20 mol% or more of its derivative, aromatic diisocyanate and/or its derivative, and lactam in a phenol-based A polyisocyanate compound masked with phenols is added to the reaction product obtained by the reaction in a solvent, in an amount of 5 to 150 parts by weight in terms of polyisocyanate, based on 100 parts by weight of the resin content of the reaction product. Characteristic method for producing polyamide-imide resin.