JPS59164328A - Aromatic polyamic acid solution composition - Google Patents

Abstract

PURPOSE:The titled composition which is highly concentrated but yet low in solution viscosity and excellent in storage stability, prepared by dissolving an aromatic polyamic acid prepared by polymerizing a specified acid component with a specified amine component in an organic solvent. CONSTITUTION:Use is made of an aromatic polyamic acid with a logarithmic viscosity (measured at 30 deg.C in a concentration of 0.5g/100ml of N-methyl-2- pyrrolidone) of 0.1-1.5, prepared by polymerizing (A) an acid component containing at least 80mol% mixture of a 3,3',4,4'-biphenyltetracarboxylic dianhydride (derivative) and a pyrotrimellitic dianhydride (derivative) at a molar ratio of 30:70-75:25 with (B) an amine component containing at least 80mol% 4,4'-diaminodiphenyl ether in substantially equimolar amounts. Namely, 5-40wt% above polyamic acid is dissolved in an organic polar solvent (e.g., dimethyl sulfoxide) to obtain the titled composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aromatic polyamic acid solution compositions. More specifically, the present invention relates to an aromatic polyamic acid solution composition particularly suitable for use as an insulating coating.

It is known that aromatic polyimide obtained by imidizing aromatic polyamic acid is particularly excellent in heat resistance, insulation, and mechanical properties. For this reason, for example, for the purpose of coating various materials, especially insulating coating of electrical materials such as electric wires, an aromatic polyimide coating is formed by applying a solution of polyamic acid to the surface of the material to be coated and then heating it to imidize it. A method of forming is commonly used.

Can aromatic polyamic acids be prepared by a polymerization reaction of a tetracarboxylic acid component and an amine component? Among these, the following are known as representative examples of the tetracarboxylic acid component and the amine component. .

Tetraka ku average 2 k difference pyromellitic dianhydride benzophenone tetracarboxylic dianhydride 3.3',
4.4'-Biphenyltetracarboxylic dianhydride 2.3.3', 4'-Biphenyltetracarboxylic dianhydride main Z reduction J 4.4''-diaminodiphenylmethane 4.4'-diaminodiphenyl ether m- P-phenylenediamine, that is, an aromatic polyamic acid obtained by polymerizing a tetracarboxylic acid component and an amine component as described above, is commonly used.Among them, pyromellitic acid is commonly used. By polymerization of acid dianhydride and aromatic cyamine (
Aromatic polyamine citric acid, which is referred to as No. 4, is relatively well known from ancient times and has been used for various purposes.

However, aromatic polyamic acid obtained by polymerizing pyromellitic a dianhydride and aromatic diamine has drawbacks in its properties and workability.

For example, when aromatic polyamic acid is used as an insulating coating, a method is generally used in which a solution of aromatic polyamic acid is applied to the surface to be coated as described above. The problem is that the aromatic polyamine chloride obtained from Aromatic Polyamine has a very poor storage stability in a solution state.

That is, a solution of aromatic polyamine chloride acid may begin to rapidly increase in viscosity and cause gelation at ambient temperature within a short period of time, or conversely cause a significant decrease in viscosity and immediately degrade. The condition becomes unsuitable for coating work. Therefore, in order to prevent extreme viscosity fluctuations of such solutions, aromatic polyamide phosphoric acid solutions are usually stored under refrigeration. However, such industrial materials that require storage in a refrigerator are extremely disadvantageous in practical terms; When used over a long period of time, there is a problem in that the above-mentioned viscosity fluctuations are likely to occur.

Furthermore, polyimide glued from pyromellitic dianhydride-based aromatic polyamic acid has a problem of low alkali resistance. For this reason, when aromatic polyamic acid obtained from pyromellitic a dianhydride is used as an insulating coating, the insulating coating tends to deteriorate easily and cause dielectric breakdown when it comes into contact with an alkaline solution. .

In addition, other known tetracarboxylic acid components (for example, 3
．． Aromatic polyamine citric acid obtained from 3',4,4'-biphenyltetracarboxylic dianhydride or 2,3,3',4,4'-biphenyltetracarboxylic dianhydride) and an amine component is an insulating material. It has drawbacks such as turbidity when baked on electric wires as a paint, alkali abrasion resistance, and insufficient salt water resistance, so it is not practical, especially when used as an insulating paint. No, no. Furthermore, the aromatic polyamic acid obtained from benzphenonetetracarboxylic anhydride and the amine component is not satisfactory for practical use, especially since the resulting polyimide does not have sufficient mechanical strength and heat resistance. No, no.

The present invention provides an aromatic polyamic acid solution that is excellent in all of the various properties listed below.

In the present invention, 3.3",4,4"-biphenyltetracarboxylic dianhydride and/or its derivatives and pyromellito W dianhydride and/or its derivatives are mixed in a ratio of 30:7.
4.4'-
Logarithmic viscosity 0.1 to 1 obtained by polymerization using substantially equimolar amounts of diaminodiphenyl ether and an amine component accounting for 80 mol% or more (preferably 90 mol% or more) of the total amine component .5[30°C10.5g
/100 mu (N-methyl-2-pyro, lydone)] of aromatic polyamide, phosphoric acid, in a certain organic polar solution.
% by weight (preferably 6-35% by weight, particularly preferably 1
0 to 35% by weight) of a polyamic alcoholic solution composition.

The aromatic polyamic brewing solution composition of the present invention contains a polymer component, that is, aromatic polyamic acid, at a high concentration, has a low solution viscosity, and is excellent in storage stability. Furthermore, the aromatic polyimide resin formed from the aromatic polyamic acid solution composition of the present invention has high heat resistance and insulation properties, and is also excellent in alkali resistance and salt water resistance. In particular, polyimide wood sword 1 formed from the aromatic polyamic acid solution composition of the present invention
Further alkali resistance is achieved by polyimides obtained from pyromellitic dianhydride-based aromatic polyimide, and 3.3', 4.4"-biphenyltetracarphone dianhydride or 2,3. This is a property that is not exhibited by any of the polyimides obtained from aromatic polyamic acids of the 3',4'-biphenyl dianhydride system, and in this respect, the present invention is particularly advantageous in practical use. be.

Therefore, the aromatic polyamic liquor solution composition of the present invention is
It is particularly useful for use as an insulating coating (for example, 7 varnish for manufacturing enamelled wire) that forms a polyimide insulating coating on the surface of an electrical material. In addition, since the aromatic polyamine chloride solution composition of the present invention has the above-mentioned excellent properties, it can be used as coating paint for various materials, dope liquid for polyimide film molding, the main component of adhesives, and various 11 organic materials. Alternatively, it can be widely used in applications such as varnish for impregnating inorganic fibrous substrates.

Next, the present invention will be explained in detail.

The aromatic polyamic acid of the present invention has a molecular weight of 3.3'.

4.4゛-Biphenyltetracarboxylic anhydride and/or its derivatives and pyromellitic dianhydride and/or
or a derivative thereof as a main component, and 4,4"
- It is obtained by polymerization with an amine component whose main component is diaminodiphenyl ether.

The main acid components of the aromatic polyamic acid of the present invention are (A) 3.3',4.4''-biphenyltetracarboxylic dianhydride and/or its derivatives and (B) pyromellitic dianhydride. and/or its derivatives, the molar ratio of A:B must be in the range of 40:60 to 75:25, and the sum of A and B must be 80% of the total acid component.
It must account for mol% or more. However, the molar ratio of A:B is preferably in the range of 45:55 to 75:25, and the total of A and B is preferably 90 mol% or more of the total acid component, so that the acid component is substantially It is particularly preferable that it consists of only A and B.

The 1f derivative λ in each of the aromatic tetracarboxylic acids described above includes tetracarbodic acids, diacids/anhydrides, diesters/anhydrides, diacid diesters, tetraesters, and the like.

The amine component preferably consists essentially only of 4,4''-diaminodiphenyl ether, but is not dominated by other diamines (preferably aromatic diamines) as long as it is less than 20 mol% of the amine component. It's okay.

4. Examples of aromatic diamines that can be used in conjunction with 4'-diaminodinoenyl ether include aromatic diamine compounds represented by the following general formulas [I], [II], and [I]. I can do it.

In the general formula [Engine], [II], [111], R1n
2, R3 is hydrogen, lower alkyl group, carboxyl group,
Represents a substituent such as a lower alkoxy group, and A is -
Represents a divalent linking group such as 5-1-CO-1-SO2-1-SO-1-CH2-.

- Among the aromatic diamine compounds represented by the general formulas [I], [I[], and [I[[], compounds preferably used in conjunction with 4,4''-diaminodiphenyl ether include 4, 4'-diaminodiphenylmetalle, 4,4'-diaminodiphenylthioether, 4,4
Examples include '-diaminodiphenylbenzophenone, 4,4'-diaminodiphenylsulfone, 0-tolidine, 0-dianisidine, 3,5-diaminobenzoic acid, and m- or p-phenylenediamine.

The aromatic polyamic acid of the present invention is obtained by polymerizing substantially equimolar amounts of the acid component and amine component as described above. In the unspecified specification, "substantially equimolar 1" means that one component is within about 3 mol% (preferably about 1 mol%) of the other component, unless both components are in a completely equimolar relationship. (within) but also includes cases where it is in excess.

Methods for obtaining polyamic acids by polymerizing various acid components and amine components are already known, and the aromatic polyamic acid of the present invention can be obtained using known methods. That is, for example, a method in which substantially equimolar amounts of an acid component and an amine component are polymerized in an organic polar solvent such as N-methyl-2-pyrrolidone: a method in which substantially equimolar amounts of an acid component and an amine component are polymerized in a small amount Polymerization method in an organic polar solvent in the presence of water: After an acid component and an amine component are reacted with an excess of the amine component to obtain an oligomer-like intermediate, this is combined with the acid component and the amine component as a whole. A method of producing a polyamic acid by adding an acid component and reacting so that the amount of the acid component is substantially equimolar; an intermediate such as an oligomer is obtained by reacting an acid component and an amine component with the acid component in excess. Thereafter, an amine component is added to this so that the acid component and the amine component are substantially equimolar as a whole, and a reaction is carried out to obtain polyamic acid; separately producing an amine-based intermediate such as an oligomer obtained by reacting an acid component and an amine component, and an acid-based intermediate such as an oligomer obtained by reacting an acid component and an amine component with an excess of the acid component, Next, these are mixed so that the acid component and the amine component are substantially equimolar as a whole (an amine component or an acid component may be added if necessary), and a reaction is performed to obtain a polyamic acid. 1 can be used.

The aromatic polyamic acid of the present invention has a logarithmic viscosity of o, i to 1.5[30°C10,5g7100m or (
The polymer must have a relatively low average molecular weight such that the average molecular weight is 100% (measured value of N-methyl-2-pyrrolidone)].

However, aromatic polyamic acids with even lower average molecular weights, such as those whose logarithmic viscosity shows a value lower than 0.1 under the above measurement conditions, are not suitable because they do not form a polyimide film with sufficient mechanical strength. Furthermore, when a high molecular weight aromatic polyamic acid exhibiting a logarithmic viscosity higher than 1.5 under the above measurement conditions is prepared into a solution containing polyamic acid at a high concentration like the solution composition of the present invention. This is not suitable because the viscosity of the solution becomes extremely high, making it difficult to handle the solution, and reducing workability.

The aromatic polyamine citric acid solution composition of the present invention contains the aromatic polyamine citric acid described above in an organic polar solvent at a high concentration, specifically from 5 to 40% by weight (preferably from 6 to 35% by weight, particularly preferably from 6 to 35% by weight). 10 to 35% by weight). Such a highly concentrated solution can also be prepared by removing the polyamine chloride produced as described above from the reaction solvent and then adding and dissolving it in a polar solvent. By using the organic polar solvent of the polyamic acid solution composition of the present invention as a reaction solvent when producing polyamic acid by polymerization, the polyamic acid solution composition of the present invention can be directly produced without taking out the polyamic acid from the reaction solution. You can also get it.

The organic polar solvent used in the aromatic polyamic acid solution composition of the present invention has a ladder point of 300°C or less at normal pressure, especially 2
508C or less is preferable, examples include N-
Methyl-2-pyrrolidone, dimethyl sulfoxide, N,
Examples include N-dimethylacetamide, N,N-dimethylformamide, N,N-diethylacetamide, N,N-diethylformamide and dimethylsulfone. Particularly preferred organic polar solvents for use in the aromatic polyamine chloride solution composition of the present invention are N-
Methyl-2-pyrrolidone, dimethyl sulfoxide, N,
N-dimethylacetamide and N,N-dimethylformamide. Note that these organic polar solvents can also be used in combination with other organic solvents such as benzene, toluene, benzonitrile, xylene, naphtha, and dioxane.

In addition, when manufacturing the composition of the present invention, a small amount (for example, about 1
9
! Preferably, it is desirable to remove as much contaminating moisture as possible from the resulting composition using a conventional drying operation such as evaporation to dryness. However, moisture that cannot be removed by normal drying operations such as drying (the amount of moisture can be determined by using the Karl Fischer method) should be contained in the composition at 3% by weight or less (preferably). (2% by weight or less), there is no problem even if it remains.

The aromatic polyamic acid solution composition of the present invention exhibits a relatively low viscosity despite containing a high concentration of polyamic acid, and the viscosity remains relatively stable even at room temperature. For example, in general, when the aromatic polyamic dairy solution composition of the present invention is stored at a storage temperature of about 30°C,
No significant viscosity change is shown over a period of approximately 3 months or more. Furthermore, even when the storage temperature is about 50', the viscosity does not show a large change for more than about one month.

Furthermore, the aromatic polyamic acid solution composition of the present invention has the advantage that it is resistant to gelation even when stored at room temperature for a long period of time. Therefore, the aromatic polyamic acid solution composition of the present invention does not require refrigeration equipment for its preservation as long as it is used under normal usage conditions.

Note that, in consideration of practical workability, the aromatic polyamic acid solution composition of the present invention preferably exhibits a rotational viscosity of 0.1 to 10,000 poise as measured at 30°C. A more preferable rotational viscosity value is 0.5 to 5000 poise, particularly preferably 1 to 2000 poise.

Next, Examples and Comparative Examples of the present invention will be shown.

[Example 1] 3.3' in a cylindrical polymerization tank with an internal volume of 300m.

4.4′-Biphenyltetracarboxylic dianhydride 20.
593 (0.07 mol), pyromellitic dianhydride 6.5
4g (0.03 mol), 4.4'-diaminodiphenyl ether 20.02g (0°1 mol), N-methyl-2
- 198.00 g of pyrrolidone and 22.00 g of water were added. This mixture was heated at a reaction temperature of 50°C and under normal pressure for 4 hours.
The polymerization reaction was carried out by stirring for 4 hours, and the logarithmic viscosity was 0.68.
[30℃, 0.5g7100m(N-methyl-2-
A reaction solution was obtained containing aromatic polyamine citric acid with a constant value of Al11 of pyrrolidone).

Next, this reaction solution was kept at 50°C and left under reduced pressure (0.01 atm) for 2 hours to evaporate and remove the water, resulting in a water content of 1.1% by weight ( A polyamic acid solution composition with a strength measured by Le Fischer titration (the same shall apply hereinafter) was obtained.

This polyamic acid solution composition had a polymer concentration (boreamink concentration, hereinafter the same) of 20.0% by weight, and a solution viscosity of 48 poise (rotational viscosity at 30'C, hereinafter the same).

The obtained polyamic acid solution composition was heated at 30°C for 30 minutes.
After being stored for 1:1, the viscosity of the solution was measured and showed 50 poise, and after being stored at 30°C for 1201", the viscosity of the solution was measured and found to be 67 poise. On the other hand, when the storage conditions were changed to 50° C. for 130 days and the solution viscosity of the above polyamic acid solution composition was measured, it was found to be 62 poise. Under any of these storage conditions, the polyamic acid solution composition described above exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

[Example 2] The reaction raw materials and solvent were 3, '3', 4,
4'-biphenyltetracarboxylic dianhydride 20
, 59 g (0.07 mol), pyromellitic dianhydride 6°54 g (0.03 mol), 4,4'-diaminodiphenyl ether 16.02 g (0.08 mol), m-7, nylene diamine 2.16 g ( 0.02 mol), 166-74 g of N-methyl-2-pyrrolidone, and 14.50 g of water
g, and the polymerization reaction was carried out in the same manner as in Example 1 except that the reaction temperature and reaction time were 70°C and 4 hours, and the logarithmic viscosity was 0.
A reaction solution containing 49 aromatic polyamic acids was obtained.

Next, a water removal operation was performed in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.9% by weight. The polymer concentration of this polyamic acid solution composition was 23.0% by weight, and the solution viscosity was 61 poise.

The solution viscosity of the obtained polyamic acid solution composition after storage at 30°C for 130 days was 64 poise, and the viscosity was 64 poise at 50°C.
The solution viscosity after storage for C130 days was 73 poise.

Under any of these storage conditions, the polyamic acid solution composition of No. 1 exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

[Example 1A3] The reaction raw materials and solvent were 17.65 g (0.06 mol) of 3.3',4,4''-biphenyltetracarboxylic acid dianhydride and 8.72 g (0.04 mol) of pyromellitic dianhydride. ), 4,4'-diaminodiphenyl ether 20.02
g (0.1 mol), dimethylacetamide 173.4
A polymerization reaction was carried out in the same manner as in Example 1, except that the reaction temperature and reaction time were changed to 3 g and 11.13 g of water, and the reaction temperature and reaction time were changed to 50'C124 hours, to obtain a reaction solution containing an aromatic polyamic acid with a logarithmic viscosity of 0.53. I got it.

Next, a water removal operation was performed in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.5% by weight. The polymer concentration of this polyamic acid solution composition was 23.8% by weight, and the solution viscosity was 68 poise.

The solution viscosity of the obtained polyamic acid solution composition after storage at 30°C for 30 days was 72 poise, and the viscosity at 50°C,
The solution viscosity after storage for 30 days was 89 poise. Under any of these storage conditions, the polyamic acid solution composition exhibited a uniform solution-like IE, and no supercipitate was observed.

When the polyamine/nic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire, it showed sufficient levels of various mechanical properties, heat resistance, and electrical properties as described below. In addition, it showed particularly excellent results in alkali resistance and salt water resistance.

Example 4 The reaction raw materials and solvent were 14.71 g (0.05 mol) of 3.3',4.4'-biphenyltetracarboxylic dianhydride and 10.91 g (0.05 mol) of pyronolyl dianhydride. ,05
mol), 4.4'-diaminodiphenyl ether 20.
02g (0.1 mol), N-methyl-2-pyrrolidone 1
Polymerization reaction was carried out in the same manner as in Example 1, except that 73.43 g and 9.13 g of water were used, and the reaction temperature and reaction time were 50° C. and 124 hours.Aromatic polyamic acid containing an aromatic polyamic acid with a logarithmic viscosity of 0.59 was used. A reaction solution was obtained.

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamine/nic acid solution composition having a water content of 0.7% by weight. The polymer concentration of this polyamic acid solution composition was 21.8% by weight, and the solution viscosity was 53 poise.

The solution viscosity of the obtained polyamic acid solution composition after storage at 30°C for 130 days was 57 poise, and
The solution viscosity after storage for C13013'' was 90 poise. Under any of these storage conditions, the above polyamic acid solution composition exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As described below, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly good results in alkali resistance and salt water resistance.

[Example 5] The reaction raw materials and solvent were 3,3',4,4'-biphenyltetracarboxylic dianhydride 11, 77 g (0,04
mole), pyromellitic dianhydride 13.09g (0,0'
6 mol), 4,4'-diaminodiphenyl ether 20
．． 02g (0.1 mol), dimethyl sulfoxide 17
A polymerization reaction was carried out in the same manner as in Example 1, except that 0.54 g of OyoU water and 8.98 g of OyoU water were used, and the reaction temperature and reaction time were 50'C524 hours. A reaction solution was obtained.

Next, a water removal operation was performed in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.5% by weight. The polymer concentration of this polyamic acid solution composition was 24.1% by weight, and the solution viscosity was 58 poise.

30°C 1301 of the obtained polyamic acid solution composition
The solution viscosity after storage for J is 63 poise and 50°
The solution viscosity after storage for C13011 was 116 boads. Under any of these storage conditions, the above polyamic acid solution composition exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

[Example 6 co-reaction raw materials and solvent were 3.3°, 4.4'-biphenyltetracarboxylic dianhydride 8.83 g (0.03 mol), pyromellitic dianhydride 15° 27 g (0.07 mol), 4.4'-diaminodiphenyl ether 16.02
g (0.08 mol), 4.4'-diaminodiphenylmethane 3.97 g (0.02 mol), N-methyl-2-pyrrolidone 169.31 g, and water 7.05 g, and the reaction temperature and reaction time were 50. A polymerization reaction was carried out in the same manner as in Example 1, except that the time was changed to .degree. Cl2O, to obtain a reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.58.

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.6% by weight. The polybu concentration of this polyamic acid solution composition was 21.331 (% by weight), and the solution viscosity was 45 poise.

r) 30°C 130 of the prepared polyamic acid solution composition
The solution viscosity after storage for +'1 is 50 poise and 5
The solution viscosity after storage at 0°C for 130 minutes was 116 poise. Under any of these storage conditions, the above-mentioned polyamine chloride solution composition exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

[Example 7] A cylindrical polymerization tank with an internal volume of 300 m and 3.3'.

4.4'-Biphenyltetracarboxylic dianhydride 19.
12g (0,065 mol), pyromellitic dianhydride 6
．． 54 g (0.03 mol), 20.02 g (0.1 mol) of 4.4"-diaminodiphenyl ether, and 188.60 g of N-methyl-2-pyrrolidone were added. The mixture was heated to a reaction temperature of 30 °C. The polymerization reaction was carried out by stirring under normal pressure for 6 hours.Next, 3.3
', 1.92 g (0,005 mol) of 4,4'-biphenyltetracarboxylic acid tetramethyl ester was added,
By dissolving it, a polyamic acid solution composition containing an aromatic polyamic acid having a logarithmic viscosity of 0.48 was obtained. The polymer concentration of this polyamic acid solution composition was 20.0% by weight and the solution viscosity was 15 poise.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

30'C! of the obtained polyamic acid solution composition! , 30
The solution viscosity after storage for 1 day was 16 Boas, and the temperature was 50°C.
The solution viscosity after storage for 30 days was 20 poise. Under any of these storage conditions, the polyamic acid solution composition of item 1- exhibited a uniform solution state, and no precipitation was observed.

[Example 8] Using 20.59 g (0.07 mol) of 3.3',4.4'-biphenyltetracarboxylic dianhydride and 5.46 g (0.025 mol) of pyromellitic a dianhydride. , and 3,3' added later.

4. A polymerization reaction was carried out in the same manner as in Example 7, except that 4'-biphenyltetracarboxylic acid tetramethyl ester was changed to 27 g (0,005 mol) of 4'-biphenyltetracarboxylic acid,
A polyamic acid solution composition containing an aromatic polyamic acid having a logarithmic viscosity of 0.66 was obtained. The polymer concentration of this polyamic acid solution composition was 20.0%, and the solution viscosity was 42 poise.

The obtained polyamic acid solution composition was heated at 30°C and 30 IJ.
The solution viscosity after storage was 45 poise and 50°C.
The solution viscosity after storage for 130 days was 60 poise. Under any of these storage conditions, the polyamic acid solution composition of No. 1 exhibited a uniform solution state, and no precipitation was observed.

The obtained polyaminic acid solution composition was evaluated as a varnish for manufacturing enamelled wire.
As described below, it showed sufficient levels of various mechanical properties, silk thermal properties, and electrical properties, and particularly excellent results in alkali resistance and salt water resistance.

[Example 9] (1) Synthesis of oligomer A 3,3' in a cylindrical polymerization tank with an internal volume of 300m.

4.4'-Biphenyltetracarboxylic dianhydride11.
77 g (0.04 mol), 4.4°-diaminodiphenyl ether4. OOg (0.02 mol) and 63.09 g of N-methyl-2-pyrrolidone were added. This mixture was stirred for 3 hours at a reaction temperature of 50°C under normal pressure to carry out the reaction. The reaction solution contains unreacted 3.3', 4.4'-
(2) Synthesis of oligomer B 13.09 g (0.06 mol) of pyromellitic dianhydride was added to a cylindrical polymerization tank with an internal volume of 300 m at 4°4. 18.02 g (0.00 mol) of '-diaminodiphenyl ether and 124.45 g of N-methyl-2-pyrrolidone were added. This mixture was stirred for 3 hours at a reaction temperature of 50°C under normal pressure to carry out the reaction. The reaction solution was a homogeneous polymer solution (polymer concentration 20% by weight, solution viscosity 2.5 poise)
Met.

(3) Production of polyamic acid solution composition Oligomer A (
78,86 g) and stirred at 50° C. for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution composition containing an aromatic polyamic acid with a logarithmic viscosity of 0.66. I got it. The polymer concentration of this polyamine-nic acid solution composition was 20.0% by weight, and the solution viscosity was 45 poise.

The solution viscosity of the obtained polyamine chloride solution composition after storage at 30°C for 130 days was 55 poise;
The solution viscosity after storage for 130 days was 100 poise.

Under any of these storage conditions, the above polyamic acid solution composition exhibited a uniform solution state, and no precipitation was observed.

When the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire,
As will be described later, in addition to showing sufficient levels of various mechanical properties, heat resistance, and electrical properties, it also showed particularly excellent results in alkali resistance and salt water resistance.

[Comparative Example 1] Pyromellitic dianhydride 21.8
1 g (0,1-+nyl), 20.02 g (0.1 mol) of 4,4'-diaminodiphenyl ether, 151' of N-methyl-2-pyrrolidone, 75 g, and 4.6 g of water.
A polymerization reaction was carried out in the same manner as in Example 1 except that the amount was 9 g and the reaction temperature and reaction time were 50'C and 140 hours to obtain a reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.59.

Next, a water removal operation was performed in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.7% by weight. The polymer concentration of this polyamic acid solution composition was 22.1% by weight, and the solution viscosity was 90 poise.

30°C 1308 of the obtained polyamic acid solution composition
The solution viscosity after storage was 155 poise, but 120 poise
After a few days, it rose by 2,000 poise. When stored at 50°C, the viscosity of the solution increased rapidly from the beginning, and after 10 days, the viscosity of the solution was 270 poise.
After 0 days, it became an insoluble gel state.

[Comparative Example 2] The reaction raw materials and solvent were 3.3', 4.4'-biphenyltetracarboxylic dianhydride 2, 94 g (0,01
mole), pyromellitic dianhydride 19°63g (0', 0
9 mol), 4.4″-diaminodiphenyl ether 20
．． 02g (0.1 mol), N-methyl-2-pyrrolidone 165.25g, and water 5.11g, and the polymerization reaction was carried out in the same manner as in Example J, except that the reaction temperature and reaction time were 50°Cl2O hours. A reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.55 was obtained.

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamine chloride solution composition having a water content of 0.8% by weight. The polymer concentration of this polyamic acid solution composition was 22.3% by weight, and the solution viscosity was 52 poise.

The solution viscosity of the obtained polyamic acid solution composition after storage at 30°C for 130 days was 77 poise. 50° again
C. When stored for 30 days, it became an insoluble gel state.

[Comparative Example 3] The reaction raw materials and solvent were 5.88 g (0.02 mol) of 3.3',4.4'-biphenyltetracarboxylic dianhydride and 17.45 g (0.08 mol) of pyromellitic dianhydride. mol), 4.4'-diaminodiphenyl ether 20.0
2g (0.1 mol), N-methyl-2-pyrrolidone 1
A polymerization reaction was carried out in the same manner as in Example 1, except that 66.5 g and 6.94 g of water were used, and the reaction temperature and reaction time were 50°CCl2O hours. I got the liquid.

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamic acid solution composition having a water content of 0.8% by weight. The polymer 6 degree of this polyamic acid solution composition was 21.7% by weight, and the solution viscosity was 60 poise.

The solution viscosity of the obtained polyamic acid solution composition after being stored at 30°C for 130 days was 86 poise. Also, 50
'C! After storage for 30 days, the solution viscosity rose sharply to 250 poise.

[Comparative Example 4] The reaction raw materials and solvent were 5.88 g (0.02 mol) of 3.3',4.4'-biphenyltetracarboxylic dianhydride and 17°45 g (0.08 mol) of pyromellitic dianhydride. mol), 4.4'-diaminodiphenyl ether 16.0
2g (0.08 mol), m-phenylenediamine 2.1
6 g (0.02 mol), N-methyl-2-pyrrolidone 1
A polymerization reaction was carried out in the same manner as in Example 1, except that 61.6 g and 4.98 g of water were used, and the reaction temperature and reaction time were 50° Cl2O hours. The reaction solution was #').

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamine chloride solution composition having a water content of 0.5% by weight. The polymer concentration of this polyamic acid solution composition was 21.2% by weight, and the solution viscosity was 54 poise.

30°C 1308 of the obtained polyamic acid solution composition
The solution viscosity after storage was 76 poise. Also, 50
After storage at °C for 30 days, the solution viscosity increased sharply to 210 poise.

[Comparative Example 5] The reaction raw materials and solvent were 3.3', 4.4'-biphenyltetracarboxylic dianhydride 29', 42 g (0,1
mol), 4.4'-diaminodiphenyl ether 20.
02g (0.1 mol), N-methyl-2-pyrrolidone 1
A polymerization reaction was carried out in the same manner as in Example 1, except that 78.00 g and 19.71 g of water were used to obtain a reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.57.

Next, water removal was carried out in the same manner as in Example 1 to obtain a polyamine chloride solution composition containing 1.0% by weight of water. The polymer concentration of this polyamic acid solution composition is 24.4% by weight, and the solution viscosity is 94%.
It was Poise.

When the storage stability of the obtained polyamic acid solution composition was tested in the same manner as in Example 1, it was confirmed that it showed a similar viscosity change and exhibited high storage stability.

However, when the polyamic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire, as described below, turbidity was observed in the formed polyimide film, and it was found that the polyimide film had poor alkali resistance and salt water resistance. were significantly inferior.

[Comparative Example 6] The reaction raw materials and solvent were 26.48 g (0,09
mol), pyromellitic dianhydride 2.18 g (0.01 mol), 4.4"-diami/diphenyl ether 20.0
2g (0.1 mol), N-methyl-2-pyrrolidone 17
Example 1 except that 5.25 g and 19.47 g of water were used.
A polymerization reaction was carried out in the same manner as above to obtain a reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.53.

Next, a water removal operation was carried out in the same manner as in Example 1 to obtain a polyamine chloride solution composition having a water content of 1.1% by weight. The polymer concentration of this polyamic acid solution composition was 23.0% by weight, and the solution viscosity was 50 poise.

When the storage stability of the obtained polyamine chloride solution composition was tested in the same manner as in Example 1, it was confirmed that it showed a similar viscosity change and exhibited high storage stability. When the polyamic acid solution composition was evaluated as a varnish for manufacturing enameled wire, as described below, the formed polyimide film was found to be cloudy, and the alkali resistance and salt water resistance were significantly poor.

[Comparative Example 7] The reaction raw materials and solvent were 23.54 g (0.08 mol) of 3,3°,4.4'-biphenyltetracarboxylic dianhydride and 4°36 g (0.02 mol) of pyromellitic dianhydride. mole), 4.4'-diaminodiphenyl ether 20t02
g (0.1 mol), N-methyl-2-pyrrolidone 172
．． A polymerization reaction was carried out in the same manner as in Example 1, except that 51 g and 19.17 g of wood were used to obtain a reaction solution containing an aromatic polyamic acid having a logarithmic viscosity of 0.50.

Next, a water removal operation was performed in the same manner as in Example 1 to obtain a polyamine chloride solution composition having a water content of 1.0% by weight. The polymer concentration of this polyamic acid solution composition was 22.4% by weight, and the solution viscosity was 41 poise.

When the storage stability of the obtained polyamine chloride solution composition was tested in the same manner as in Example 1, it was confirmed that it showed a similar viscosity change and exhibited high storage stability.

However, when the polyamine/nic acid solution composition obtained here was evaluated as a varnish for manufacturing enameled wire, as described below, turbidity was observed in the formed polyimide film, and the alkali resistance and Salt water resistance was significantly inferior.

[Evaluation of aromatic polyamic acid solution compositions as varnishes for manufacturing enameled wires] Regarding the aromatic polyamic acid solution compositions of Examples 1 to 9 and Comparative Examples 1 to 7 described above, evaluations were made for the compositions of aromatic polyamic acid solution compositions as varnishes for manufacturing enameled wires. Evaluation was performed by the following method.

(1) Manufacture of enamelled wire Enameled wires were manufactured using a vertical enamelled wire baking furnace in which the temperature of the furnace was maintained at 400°C and a wire speed of 5 m for 7 minutes according to the conventional method. A sample with a diameter of 1°0 mm was used, and the number of applications was 8 times.

(2) Evaluation of enameled wire The coating of the enameled wire was evaluated for appearance, salt water resistance, and alkali resistance. Note that salt water resistance and alkali resistance were evaluated as follows.

11. In the water! According to JISC 300311, 1, make a test piece from two pieces, immerse the twisted part for 10 cm in a 0.4% by weight aqueous sodium chloride solution kept at 30°C, and
Apply 200V AC to the wooden conductor tube, and 0. The time required for the current to flow to I was all determined.

Alkali resistance (Alkali, -) Prepare two test pieces in the same manner as in -1-, and immerse the twisted part for 10 cm in a 10% by weight aqueous sodium hydroxide solution kept at 50°C. Apply 200V AC to the wooden conductor tube, and 0. The time required for IA current to flow was measured.

The evaluation results are shown in Table 1.

Table 1 Appearance Saltwater resistance Alkali resistance (hours) (hours) Example 1 Good >1000 152 Good
>1000 143 Good >1000'
13.54 Good >1000 13
5 Good >1000 11.56 Good >1000 9.57 Good >1
ooo 148 Good >1000
13', 59 Good >1000 12.5
Comparative Example 1 Good >1000 <12 Good >1000 <13 Good >1'0
．． OO' 1, 34 Good >1000
<15 Turbidity Right 3<1 6 Turbidity 15 Ku1 7 Turbidity 80 Ku1 Next, the results of enameled wires manufactured using the aromatic polyamine ink solution compositions of Examples 1 to 9 and Comparative Example 1 as varnishes were examined. The evaluation results of other characteristics are shown.

(1) The coating thickness (gm), number of pinholes (15 m), wear resistance (load 70og), and dielectric breakdown voltage (KV) of the enameled wire showed good values as shown in Table 2.

Table 2 Coating thickness Pin Abrasion resistance Dielectric breakdown (min) Hall Voltage (KV) Example 1 42 0 98 11.82 40
0 87 13.23 41 0
84″ 12.54 43 0 72
i2. .

5 40 0 69 12.36 42
0 63 Ll, 97 41 0
83 11.98 41 0 85
L2.29 40 0 76 13.
0 Comparative Example 1 42 0 12 11,. 7 (2) Flexibility (self-diameter winding): All passed (3) Deterioration resistance (200
°C 124 hours, self-diameter winding); All passed (4) Thermal shock resistance (250 °C, 1 hour, self-diameter winding):
All passed (5) FIFj heat softening (2.1 kg, 1 hour, 300
°C): Passed in all [Evaluation of mechanical strength of polyimide films obtained from aromatic polyamic acid solution compositions] Polyimide films were produced from the polyamic acid solution compositions of Examples 1 to 9 by the following method. , its mechanical strength was evaluated.

Using a doctor knife, apply the polyamic acid solution composition onto a glass plate in the form of a thin film of uniform thickness. This thin film was dried for 30 minutes in a nitrogen atmosphere and solidified to form a film.The film was heated to 300°C over 1 hour, and then heat-treated at 300°C for 30 minutes to a thickness of 25mm.
A polyimide film of Lm was obtained.

The tensile strength, elongation at break, and heat resistance of the above polyimide film were measured by the following methods. The measurement results are shown in Table 3.

(1) Tensile strength (medium: kg/mm') and elongation at break (unit: %) Using Autograph DSS-5000 (manufactured by Takasugi Seisakusho) for a sample with a length of 100 mm and a width of 10 mm, the distance between chucks was 50 mm. , and was measured at a pulling speed of 50 mm/min.

(2) Heat resistance (unit: weight loss on heating %) Place the polyimide film on a thermobalance and heat at a rate of 10°C in an air atmosphere.
/min and the weight loss of the film was measured when it reached 500°C.

Table 83 Example Tensile strength Elongation at break Heat resistance (kg/
mrn') (%) (praise,%)1
19.1 74 <52 18.
5'70 <53' 19.
3 76 <54 18.1
90 <55 17.8 85
<56 17.3 67 <
57 15.9 70 <58
19 , 8 75 <59 17
．． 9 77 <5259-

Claims (1)

[Claims] ■. 3.3',4.4'-biphenyltetracarphonic dianhydride and/or one derivative thereof and pyromellitic dianhydride and/or its derivative at a concentration of 30 nia 0 to 75
25 molar ratio, and these compounds account for 80 mol% or more of the total acid component, and 4,4"-diaminodiphenyl ether accounts for 80 mol% or more of the total amine component." The logarithmic viscosity obtained by polymerization is 0.1 to 1.5 [30°C 10.5 g/100 m
1 (N-methyl-2-pyrrolidone)] is dissolved in an organic polar solvent in an amount of 5 to 40%. The molar ratio of 2°3.3',4.4°-biphenyltetracarboxylic dianhydride and/or its derivative and pyromellitic dianhydride and/or its derivative is 40:55.
The polyamic acid solution composition according to claim 1, characterized in that the molar ratio is 60:25. 3゜More than 90 mol% of the total dairy component is 3,3'. 4. The polyamic acid solution composition according to claim 1 or 2, which comprises 4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride. The polyamic acid according to claim 3, wherein the 4° acid component consists essentially of 3.3', 4.4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride. Solution composition. The polyamic acid solution composition according to any one of claims 1 to 4, characterized in that the 5° amine component consists essentially of 4,4''-diaminodiphenyl ether. 6° Aromatic Group polyamic acid is present in an organic polar solvent from 10 to
The polyamic acid solution composition according to any one of claims 1 to 5, characterized in that 35% by weight of the polyamic acid solution is dissolved. 7゜The organic polar solvent is N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide,
and N,N-dimethylformamide, or a mixture thereof, as claimed in any one of claims 1 to 6.