JPH0241319A - Thermoplastic polyimide polymer - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic polyimide polymer, containing respective specific three kinds of constituent units in a specified proportion, having a specific inherent viscosity and good melt fluidity capable of injection molding and excellent in heat resistance and mechanical characteristics. CONSTITUTION:A thermoplastic polyimide, obtained by reacting, e.g., 3,3',4,4'- biphenyltetracarboxylic acid dianhydride with bis[4-(4-aminophenoxy) phenyl]sulfone and bis(4-aminocyclohexyl)methane in an organic polar solvent, such as N,N-dimethylacetamide, etc., containing constituent units expressed by formulas I and II (X is group expressed by formula III, etc.) in amounts of 0.9-1.1mol total amount of the units expressed by formulas II and IV based on 1mol units expressed by formula I at (80/20)-(20-80) molar ratio of the units expressed by formula II/units expressed by formula IV, having 0.2-5.0dl/g inherent viscosity at 0.5g/dl concentration in concentrated sulfuric acid at 30 deg.C and suitable as heat-resistant materials in the industry of electrical and electronic device, etc.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a novel thermoplastic polyimide polymer that can be injection molded, has good melt flowability, and has excellent heat resistance and mechanical properties. It is.

<Conventional technology> Polyimide has excellent heat resistance, mechanical properties, electrical properties,
Due to its sliding properties, it has become synonymous with high-performance resins and is already used in various fields. Among them, a typical polyimide is disclosed in U.S. Patent No. 3,179,631, and has a ratio of each structural unit of the type B+C IT II O0 to 1 mole of A, which is a polyimide that is It is famous for having the highest heat resistance. However, this polyimide has almost no melt moldability and can only be molded by a special method called compression molding, which has the disadvantage of low molding production efficiency. In addition, as a polyimide with improved moldability, polyimide expressed by the general formula % is disclosed in Japanese Patent Publication No. 52-39880,
A polyimide represented by the general formula % is disclosed in the above publication. However, these polyimides still have a high thermal softening point, and even if they are melted, their viscosity is so high that it is difficult to obtain molded articles by injection molding.

Further, in JP-A-60-40131, a polyimide film represented by the formula is also disclosed as a moisture-resistant polyimide.
JP-A-141731 discloses a polyimide film represented by the following formula as a transparent polyimide.

<Problems to be Solved by the Invention> However, when viewed as a molding material, the polyimide described in the above publication also has low meltability and is difficult to apply to injection molding.

As described above, polyimides that have been conventionally proposed do not have sufficient moldability when viewed as melt molding materials, and further improvement is required.

Therefore, the object of the present invention is to obtain a thermoplastic polyimide polymer that maintains the excellent properties inherent to polyimide, has improved melt fluidity, and can be used as an injection molding material.

Means for Solving the Problems〉 As a result of intensive studies by the present inventors to solve the above problems,
The inventors have discovered that a thermoplastic polyimide polymer having crushed properties can be obtained by combining a specific tetracarboxylic acid component and a specific diamine component, and have arrived at the present invention.

That is, the present invention A0 type 00 %formula% CH.

The structural units of F s OcHs CFS) and the proportion of each structural unit are B+C
is 0.9 to 1.1 mol, and the molar ratio of B/C is 80/20 to
20/80, and in concentrated sulfuric acid, concentration 0.5t/dj
, the logarithmic viscosity measured at a concentration of 30°C is 0.2 to 5.
It is a thermoplastic polyimide polymer in the range of 0 dJ/g.

The thermoplastic polyimide polymer of the present invention has an acid component corresponding to the A unit, that is, 3.3-. 4.4-Biphenyltetracarboxylic acids (e.g. dianhydride, diester) and B
and the diamine component corresponding to the C unit, i.e. bis[4-(4-aminophenoxy)phenyl] as the B unit.
Sulfone, bis[4-(4-aminophenoxy)phenylkoketone, 2.2-bis[4-(4-aminophenoxy)phenyl]propane, 2.2-bis[4-(4-aminophenoxy)phenyl] Produced by reacting at least one type of hexafluoropropane with bis(4-aminocyclohexyl)methane as a C unit in an organic polar solvent to obtain a polyamic acid, and then imidizing it by a dehydration ring closure reaction. be able to. here,
As the B unit, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is particularly preferred.

In addition, the degree of polymerization of the polyimide produced can be controlled by adjusting the molar ratio of the acid component and the diamine component, but in order to ensure a practical degree of polymerization as a molding material, it is necessary to So, B10 is 0.9 ~
It is necessary that the amount is 1.1 mol, preferably in the range of 0.95 to 1.05 mol.

The polyimide of the present invention has a logarithmic viscosity (ηinh) of 0 when measured in concentrated sulfuric acid at 0.5 t/dj and a temperature of 30°C.
, 2 to 5, and 0 dJ/g. If the logarithmic viscosity is less than 052 dJ/, the strength of the molded product will decrease, which is undesirable;
In the above, the melt viscosity becomes too high, which is not preferable, and the more preferable range of logarithmic viscosity is 0.3 to 2.5 dJ/.

In the polyimide of the present invention, the molar ratio of B units to C units is 80/20 to 20/80, preferably 70/30.
~30/70. If the B@ position is greater than this range, the melt viscosity will be high and injection molding will be difficult. Conversely, polyimides with more C units than the range of the present invention,
Although it can be injection molded, it yields extremely brittle molded products, making it difficult to use as a practical material.

However, the polyimide of the present invention has good moldability by keeping the ratio of B units and C units within an appropriate range,
It also provides molded products with excellent mechanical properties. Furthermore, it has been found that the polyimide of the present invention has almost no decrease in heat resistance compared to a polyimide consisting only of A and B units.

That is, generally an improvement in moldability leads to a decrease in heat resistance, but in the polyimide of the present invention, although C units are introduced into A and B units and moldability is improved, the heat distortion temperature is It does not decrease significantly, and in particular, when 2,2-bis[4-<4-aminophenoxy)phenyl]propane is used as the B unit, the heat distortion temperature is maintained at exactly the same level.

Examples of organic polar solvents used in polymerizing the polyimide of the present invention include amide solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone, phenol, cresol, chlorophenol, and xylenol. For polyamic acid, the tetracarboxylic acid component and diamine component of the raw materials are heated at 0 to 100℃. Although it can be produced by reacting within a range of 0.5 to 10 hours, it is also possible to carry out the reaction at a temperature of 100° C. or higher to simultaneously perform the polyamic acid synthesis reaction and the imidization ring-closing reaction. However, in order to obtain a highly polymerized product,
The polyamic acid synthesis reaction is carried out at 100°C or lower, preferably at 60°C.
It is preferable to carry out the process at a temperature below 0.9°C.

There are various methods for converting polyamic acid into polyimide by dehydration and ring closure, and representative methods can be broadly classified into the following three methods.

(1) Thermal ring closure method in solution Preferably, the polyamic acid solution is heated to 100°C or higher as it is.

Preferably, imidization is performed by heating to 120° C. or higher. Here, triethylamine, pyridine, N, N
- The reaction rate can be accelerated by adding a tertiary amine such as dimethylaniline (for example,
30060, etc.).

(2) Chemical ring closure method A dehydrating agent is added to the polyamic acid solution to chemically close the imide ring. As the dehydrating agent, aliphatic acid anhydrides such as #acid anhydride and propionic anhydride are suitable. Further, the reaction rate can be accelerated by the coexistence of a tertiary amine. Although the reaction proceeds satisfactorily at room temperature, it may also be carried out under heating. Furthermore, when polyimide is used as a film, a technique such as casting a polyamic acid solution onto the film and then immersing it in a dehydrating agent is also used (for example, Japanese Patent Publication No. 37-97).

(3) Precipitation method A polyamic acid solution is poured into a solvent that does not dissolve polyamic acid (for example, toluene, benzene, hexane, methanol, water, etc.) to precipitate/precipitate polyamic acid. After filtering/recovering the obtained powdered polyamic acid,
℃ or higher, preferably 120℃ or higher, particularly preferably 17
When heated above 0°C, an imidization reaction occurs. Furthermore, it is also possible to add the dehydrating agent mentioned in (2) in advance to the poor solvent for polyamic acid to cause imide ring closure to occur simultaneously with precipitation/precipitation (for example, U.S. Patent No. 3,
179,631, JP-A-61-234, etc.).

The above three methods are not necessarily independent methods, and a combination of each method may also be used. In addition, the easiest method in terms of operation is the thermal ring-closing method in a solution (1), but polyimides imidized by methods (2) or (3) tend to have better physical properties. .

Further, the polyimide of the present invention can be combined with a diisocyanate derived from the diamine used in the present invention and 3.3", 4.
It can also be produced by reacting with 4-biphenyltetracarboxylic acids.

In this case, polyimide is produced directly without going through polyamic acid.

The thermoplastic polyimide of the present invention may remain in the form of amic acid viscosity, which is a precursor whose imide units are partially ring-closed, but if the ring closure rate is low, gas will be generated during molding, so most of the It is preferable to imidize it.

Since the thermoplastic polyimide of the present invention has excellent melt flowability, it can be molded into a desired shape by applying ordinary plastic molding methods. A particular feature is that injection molding can be used, and compared to polyimide, which can only be produced by conventional compression molding, the production efficiency of molding can be greatly increased.

A suitable molding temperature is 300 to 400°C.

The polyimide of the present invention has an extremely excellent balance between melt fluidity and thermal stability in this temperature range.

If necessary, various fillers can be added to the thermoplastic polyimide of the present invention to impart desired properties. Such fillers include (a) wear resistance improvers: graphite, carborundum, molybdenum disulfide,
Boron nitride, fluororesin, etc. (b) Reinforcement materials Niglass fiber, carbon fiber, aramid fiber, boron fiber, silicon carbide fiber, carbon whisker, metal fiber, etc. (c) t!
Flammability improvers: antimony ditrioxide, magnesium carbonate, calcium carbonate, etc.; (d) air resistance improvers: clay, mica, etc.; (e) tracking resistance improvers: diasbestos, silica, etc.; (f) acid resistance improvers. : Barium sulfate, silica, calcium metasilicate, etc., (g) diiron thermal conductivity improver,
Zinc, aluminum, copper, etc., (h) Other Nigaras beads, alumina, talc, geometallurgical earth, aqueous alumina,
Examples include potassium titanate whiskers, various metal oxides, and inorganic pigments.

<Example> Hereinafter, the present invention will be explained in further detail with reference to Examples.

In addition, physical property measurements in Examples were performed according to the following method.

Bending strength: ASTM D790-71 Heat distortion temperature: ASTM D648-56 (load 18.56k
Irf/aa) In addition, the logarithmic viscosity, which is a guideline for the molecular weight of the polymer, is for polyamic acid in N,N-dimethylacetamide,
It was measured at a concentration of 0.5 g/dJ and a temperature of 30°C. in M, concentration 0.5sr/dJ,
Measurement was performed at a temperature of 30°C.

Example 1 147.8 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 50.5 g of bis[4-aminocyclohexylcomethane were placed in a 5J four-bottle flask, and further N,N-dimethyl Acetamide 3. Add Oj to make a homogeneous solution, 3.3-. 4.4°
-176.5 g of biphenyltetracarboxylic dianhydride was added to the water-cooled body, and stirring was continued for an additional hour to obtain a polyamic acid solution with a logarithmic viscosity of 0.80 dJ/min.

Next, this solution was gradually added to 30J of water with vigorous stirring, and the resulting precipitate was allowed to pass through. After pulverizing this using a sample mill manufactured by Hosokawa Micron Co., Ltd., washing and filtration were repeated twice with water. The obtained powder was dried in a hot air dryer at 100°C for 8 hours, and then heat-treated in a vacuum dryer at 230°C for 5 hours to obtain polyimide powder 325f.

Next, this powder was supplied to a Brabender Plastograph extruder and extruded into pellets while melt-kneading at a processing temperature of 350°C. The logarithmic viscosity of this pellet was measured and found to be 0.60 dll/g. Subsequently, the pellet was injection molded (barrel temperature 330~3
50℃, mold temperature 150-170℃, injection pressure 1.20
0 to 1, 400 kg f/aJ), and physical properties were measured. As shown in Table 1, both strength and heat resistance were excellent.

The theoretical structural units of the polymer that can be used here are as follows. The results of elemental analysis were as shown below, and showed good agreement with the theoretical values.

Elemental analysis results m/n = 60/40 Example 2 In Example 1, 98°5 g of 2.2-bis[4-(4-aminophenoxy)phenylcopropane,
- Polymerization and molding were carried out in substantially the same manner, except that 75.7 g of aminocyclohexylcomethane was used,
Get a test piece. The physical property measurement results are shown in Table 1, and the melt moldability was excellent and the properties were good.

Comparative Example 1 In Example 1, the diamine used was 2゜2-bis[4-(4-aminophenoxy)phenyl]propane 2
Polyimide powder was obtained by polymerization in substantially the same manner except that only 46.3 g was used. Example 1
An attempt was made to pelletize using the same method as above, but the melt fluidity was poor and the load current applied to the screw shaft exceeded the allowable range, making pelletization impossible. Furthermore, when the processing temperature was raised to 400° C., although extrusion became possible, foaming and gelation due to decomposition of the resin were observed, and good pellets could not be obtained in the end.

Therefore, the powder was then subjected to a compression molding machine and molded under conditions of a temperature of 380° C. and a pressure of 1000 h f/- to obtain a molded plate, which was cut and subjected to measurement of physical properties.

The results are shown in Table 1, and compared to the polyimides of Examples 1 and 2, the thermal properties were at the same level and the bending strength was slightly inferior. Furthermore, since it could only be compression molded, it was found that the molding productivity was extremely low compared to the polyimide of Example 1.2, which could be injection molded.

Comparative Example 2 Polyimide powder was obtained by polymerizing in substantially the same manner as in Example 1, except that 126.2 g of bis[4-aminocyclohexylcomethane was used as the diamine. This powder was pelletized and injection molded in the same manner as in Example 1, and then its physical properties were measured, and the results shown in Table 1 were obtained. That is, although this polyimide can be injection molded, its mechanical properties are extremely low and it has been found to be impractical.

Table 1 Note) Comparative Example 1 (Measurement of υm for Living Room I)

Example 3 In a 51-four-loop flask, 181.6° of bis[4-(4-aminophenoxy)phenyl]sulfone and bis[4
Add 37.9 g of -aminocyclohexylcomethane, and add 3.9 g of N,N-dimethylacetamide. OJ! was added to make a homogeneous solution.

Next 3.3-. 4. Add 176.5 g of 4-biphenyltetracarboxylic dianhydride to the water-cooled body, and -
By continuing to stir for hours, the logarithmic viscosity is 0.78dj/
g of polyamic acid solution was obtained.

Subsequently, a powder was obtained by the same treatment as in Example 1, followed by pelletizing and injection molding, and the physical properties were measured.

The results are shown in Table 2, and the moldability was excellent, and both strength and heat resistance were good.

Comparative Example 3 In Example 3, the diamine used was bis[4-(4
-aminophenoxy)phenyl]sulfone259. ”i
Polyimide powder was obtained by polymerization in substantially the same manner except that only t was used.

An attempt was made to pelletize this powder in the same manner as in Example 3, but due to poor melt flowability, it was not possible to obtain good pellets, and injection molding was also impossible.

Table 2 Note) a): Unable to beretize Example 4 In a 5j four-necked flask, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane 155
．． 5 g and 63.1 g of bis[4-aminocyclohexylcomethane, and further added 3.5 g of N,N-dimethylacetamide. 3.3-.
4.4-Biphenyltetracarboxylic dianhydride 176.
5 g was gradually added under water cooling and stirring was continued for an additional hour to obtain a polyamic acid solution with a logarithmic viscosity of 0.71 dj/g.

Subsequently, a powder was obtained by the same treatment as in Example 1, and then pelletized and injection molded to measure the physical properties. The results are shown in Table 3, and the moldability was excellent, and both strength and heat resistance were good.

Comparative Example 4 In Example 4, the diamine used was 2,2-bis[
Polyimide powder was obtained by polymerization in substantially the same manner except that 311.1 g of 4-(4-aminophenoxy)phenyl]hexafluoropropane was used. An attempt was made to pelletize this powder in the same manner as in Example 4, but due to poor melt flowability, it was not possible to obtain good pellets, and injection molding was also impossible.

Table 3 Note) a): Non-pelletizable Example 5 51 Into a four-loaf flask, 119. Og and bis[4-
63.1 t of aminocyclohexylcomethane was added, and 3.0 J of N,N-dimethylacetamide was added to make a homogeneous solution. Next, 3.3-. 4.4-- and 176.5 sr of phenyltetracarboxylic dianhydride were water-cooled and gradually added thereto, and stirring was continued for an additional hour to obtain a polyamic acid solution with a logarithmic viscosity of 0.76 dj/.

Next, a powder was obtained by the same treatment as in Example 1, and then pelletized and injection molded to measure its physical properties.The results are shown in Table 4. It was in good condition.

Comparative Example 5 In Example 4, the diamine used was bis[4-(4
Polymerization was carried out in substantially the same manner except that 237.9 g of -aminophenoxy) phenylcogetone was used,
Polyimide powder was obtained.

An attempt was made to pelletize this powder in the same manner as in Example 5, but due to poor melt flowability, good pellets could not be obtained and injection molding was also impossible.

Table 4 Note) a): Unable to pelletize (Effect of the invention) The thermoplastic polyimide of the present invention has good melt moldability and has the excellent mechanical strength and heat resistance inherent to polyimide. Therefore, the injection molding method, which has high molding productivity, can produce high-performance molded articles.
It is useful as a heat-resistant material in the space industry, etc.

Claims (1)

[Claims] A, structural unit of formula ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ B, formula ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ (in the formula, ▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ It consists of the structural units ▼, and the ratio of each structural unit is 0.1 mole of A to 1 mole of B+C.
9 to 1.1 mol, B/C molar ratio 80/20 to 20/
80, and the logarithmic viscosity measured in concentrated sulfuric acid at a concentration of 0.5 g/dl and a concentration of 30°C is 0.2 to 5.0 dl.
/g of thermoplastic polyimide polymer.