JPH01149830A - Thermoplastic aromatic polyimide polymer - Google Patents

Abstract

PURPOSE:To provide the title polyimide polymer having a specific inherent viscosity, excellent in the heat resistance and strength thereof and capable of being injection-molded, by comprising 3,3',4,4'-diphenyl sulfone tetracarboxylic acid dianhydride and a specified aromatic diamine containing ether groups. CONSTITUTION:(A) 3,3',4,4'-Diphenyl sulfone tetracarboxylic acid dianhydride and (B) a long-chain aromatic diamine containing diphenyl ether bonds {e.g., bis[4-(4-aminophenoxy)phenyl] sulfone} are mixed in a solvent to form a polyamic acid solution, which is added to a solution containing acetic anhydride, phridine, etc., for a reaction thereof to provide the objective polymer containing the repeating units of the formula [X is SO2, CO, C(CH3)2 or C(CF3)2] as a main component and having an inherent viscosity of 0.2-5.0dl/g measured under conditions consisting of a concentration of 0.5g/dl and a temperature of 30 deg.C in concentrated sulfuric acid.

Description

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

<Conventional technology> Polyimide has excellent heat resistance, mechanical properties, electrical properties,
Because of its sliding properties, it has become synonymous with high-performance resins and is already used in various fields. Among them, a typical polyimide is the polyimide disclosed in U.S. Pat. No. 3,179,631, which is famous for having the best heat resistance among existing polymers. However, this polyimide has almost no melt moldability and can only be molded by a special method called compression sintering, so it has the disadvantage of low molding production efficiency. On the other hand, as a polyimide with improved moldability, Japanese Patent Publication No. 52-3988
The polyimide represented by the general formula % is disclosed in Japanese Patent Application Laid-open No. 61-250031.
The polyimide represented by the general formula % is also disclosed in Japanese Patent Application Laid-Open No. 61-28526.
The publication discloses a polyimide represented by the general formula. However, these polyimides still have a high thermal softening point, and even if they are melted, their viscosity is too high, making it difficult to obtain molded articles by injection molding.

<Problems to be Solved by the Invention> As described above, polyimides conventionally proposed do not have sufficient moldability when viewed as melt molding materials, and further improvement is required. Therefore, the inventors of the present invention discovered the inherent advantages of polyimide.
As a result of intensive studies to improve melt flowability while maintaining core properties, we have developed a new thermoplastic aromatic polyimide polymer with excellent properties by combining a specific tetracarboxylic acid component and a specific diamine component. The present invention was achieved by discovering that coalescence can be obtained.

Means for Solving the Problems〉 That is, the present invention has a repeating unit represented by -formation (I) A thermoplastic aromatic polyimide polymer CF having a logarithmic viscosity measured in the range of 0.2 to 5.0 d (I/f).

-C- is shown. ).

CF3 The thermoplastic polyimide of the present invention has a balance between physical properties and moldability due to the patented combination of a tetracarboxylic acid component having a diphenyl sulfone structure and a long-chain aromatic diamine component containing a diphenyl ether bond. Become an excellent child.

The thermoplastic polyimide of the present invention is produced by reacting 3.3', 4°4'-diphenylsulfone tetracarboxylic acid or its derivatives (e.g., dianhydride, diester, etc.) with the corresponding diamine in a polar solvent. After that, it can be produced by imidization by dehydration and ring closure.

Specific examples of raremis used in the present invention include bis(4-(4-aminophenoxy)phenyl)sulfone,
Bis(4-(3-aminophenoxy)phenyl)sulfone, bis[4-(4-aminophenoquine)phenylkoketono, bisC4=C3-aminophenoxy)phenylkoketono, 2.2-bis(4-( 4-aminophenoquine)
phenyl]propane, 2,2-bis[4-(3-allophenoxy)phenyl]propane, 2,2-bis[4-(
Examples include 4-aminophenoxy)phenyldihexafluoropropane.

When reacting the tetracarboxylic acid component and the diamine component, the degree of polymerization of the resulting polyimide can be controlled by adjusting their molar ratio.

In order to produce polyimide with a high degree of polymerization, the molar ratio should be set to 0.
It is desirable to select from the range of 9 to 1,11, preferably 0.95 to 1.05. The degree of polymerization can also be adjusted by adding a terminal capping agent such as phthalic anhydride, benzoyl chloride, or aniline.

The polyimide of the present invention has a concentration of 0.5 f/de in concentrated sulfuric acid.
, the logarithmic viscosity measured at a temperature of 30°C is 02 to 5.0.
dl/f range, but if the logarithmic viscosity is less than 0.2 dβ/g, the strength of the molded product will be low, which is not preferable, and if it is 5.0 dl/f or more, the melt viscosity will be too high, which is not preferable. do not have. A more preferable range of logarithmic viscosity is 04 to 285 dp7y.

Solvents that can be used during polymerization include N,
Examples include amide solvents such as N-dimethylacetamide, N,N-remethylformamide, and N-methylpyrrolitono, and phenolic solvents such as phenol, cresol, chlorophenol, and xylenol, but as long as they can dissolve polyamic acid. For example, other solvents may be mixed. Polyamic acid can be produced by reacting the raw materials tetracarboxylic acid component and diamine component at a temperature of 0 to 100°C for 05 to 10 hours. It is also possible to carry out the imidization ring-closing reaction simultaneously. However, in order to obtain a highly polymerized product, the polyamic acid synthesis reaction requires 10
It is desirable to carry out the reaction at a temperature of 0°C or lower, preferably 60°C or lower.

There are various methods of dehydrating and ring-closing polyamic acid to convert it into polyimide, which can be roughly classified into the following three methods.

(I) Thermal ring-closing method in solution Riimidization is carried out by heating the polyamic acid solution as it is to 100° C. or higher, preferably 120° C. or higher. Here, the reaction rate can be accelerated by adding one tertiary amino such as triethylamine 7, pyridine, N, N-methylanili 7, etc.
060, 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 acetic anhydride and propionic anhydride are suitable. By coexisting Masuko tertiary amine, the reaction rate can be accelerated. 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 method such as casting a polyamic acid solution onto the film and then immersing it in a dehydrating agent bath is also used (for example, Japanese Patent Publication No. 37-97).

(3) Precipitation method Boria iF acid solution is dissolved in polyamic acid, and Nai solvent (
(e.g., badruene, 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 at the same time as the precipitation/precipitation (for example, US Pat.
．． 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 method (I) that is easy to use with a trowel is the thermal ring-closing method in a solution, but polyimides imidized using methods (2) or (3) tend to have better physical properties in molded products. .

Moreover, the polyimide of the present invention is a diisocyanate derived from the diamine used in the present invention),! =3.3',
It can also be produced by reacting 4.4'-diphenylsulfonetetracarboxylic dianhydride. In this case, polyimide is produced directly without going through polyamic acid.

The thermoplastic polyimide of the present invention has the repeating unit of general formula (I) as the main structural unit, but other copolymer components may be introduced as long as the properties are not impaired (in particular, the melt flowability is not reduced). You can also do it. Acidic copolymerizable components that can be copolymerized include pyromellitic acid, 3.3', 4.4'-benozophenonetetracarboxylic acid, 3.3', 4.4'-biphenyltetracarboxylic acid, 2,3 .3',4'-biphenyltetracarboxylic acid, 3.3',4.4'-biphenyl ethertetracarboxylic acid, 1,2.5.6-naphthalenetetracarboxylic acid, 2゜2-bis(3, Mention may be made of 4-dicarboxyphenyl)hexafluoropropane and derivatives thereof. In addition, examples of diamines that can be copolymerized include paraphenylenediamine,
Metaphenylene diamino, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'
-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl ketone, 3,3'-diaminodiphenyl ketone, 21
2-bis(4-aminophenyl)propane, 214-diaminotoluene, 2,6-diamino-1-toluene, hexamethylene diamine, octamethylene diamine, bis(4
-aminocyclohexyl)methane, etc., and copolymerizable diisocyanates include those obtained by converting the amino group of the above-mentioned diamino into an isocyanate group. If these copolymerized components are used in large amounts, they will impair the properties aimed at by the present invention, so their content should be 50 mol% or less, preferably 3.
It should be kept below 0 mol%.

In the thermoplastic polyimide of the present invention, the imide unit may remain in the amic acid bond which is a partially ringed precursor, but if the ring closure rate is low, gas will be generated more during molding, so most of the imide units are 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 conventionally compression molded, 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., mountain reinforcing agent, glass fiber,
Carbon fibers, aramid fibers, boron fibers, silicon carbide fibers, carbon whiskers, metal fibers, etc. (C) Flame retardant improvers ° antimony trioxide, magnesium carbonate, calcium carbonate, etc. (small electrical property improvers: clay, Mica, etc., (e) Toratsukinog resistance improver, asbestos, Nonritsu J, etc.
(f) Acid resistance improvers: barium sulfate, phosphoric acid, calcium metasilicate, etc., (g) Thermal conductivity improvers: iron, zinc,
Aluminum, copper, etc., O〕)Other glass beads,
Examples include compounds such as alumina, curcum, diatomaceous earth, hydrated alumina, potassium titanate Q iscar, various metal oxides, and inorganic pigments.

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

Note that measurements of various physical properties were performed according to the following methods.

Bending strength: Φ・ASTM D790 In addition, the logarithmic viscosity, which is a guideline for the molecular weight of the polymer, is N for polyamic acid, N - *Concentration 0 in methylacetamide
The measurement was carried out under the conditions of 5g/dβ and the temperature of 30°C, and the polyimide was measured in concentrated sulfuric acid at a concentration of 052/dlV1 and the temperature of 30°C.

Example 1 2,2-bis[4-(4-aminophenoxy)phenyl]propane 246.3 F (
0.6 mol) and NUN-i; methyl 7cetamide 4
．． 04 was added and stirred well to form a homogeneous solution. next,
3,3',4,4'-Diphenylsulfone tetracarboxylic dianhydride 215. synthesized according to the method of U.S. Pat. No. 3,022,320. Of (0.6 mol) 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 1.02 dβ/f.

Next, this solution was gradually added to a mixture of 30e1 of toluene, 1.541 acetic anhydride, and 15β pyrylene with vigorous stirring, and the resulting precipitate was filtered. This was washed twice with acetonate, dried in a hot air dryer at 100°C for 8 hours, further pulverized, and then dried in a vacuum dryer at 230°C for 5 hours to obtain polyimide powder 380f. A pantam mill manufactured by Hosokawa Microno Co., Ltd. was used for the pulverization.

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

COCCH3 1] 11 A C43N2 s N20s S + Elemental analysis result Next, the obtained polymer powder was mixed with Brabenderp-17-0
1 to the last graph extruder, processing temperature 36
The mixture was extruded and formed into pellets while being melted and kneaded at 0°C. When the logarithmic viscosity of this pellet was measured, it was 0.56 d1
It was 7/g. Subsequently, the pellets were transferred to an injection molding machine (barrel temperature 350-370°C, mold temperature 180-200°C).
C1 ejection pressure 1.400-1.800 kq f /
d) A test piece was prepared and the physical properties were measured, and as shown in Table 1, it was found to be excellent in both strength and heat resistance.

Examples 2 to 6 Polymerization and polymerization were carried out in the same manner as in Example 1, except that the diamino shown in Table 2 was used instead of 2.2-bis[:4-(4-aminophenoxy)phenyl]propane. Injection molding was performed.

Table 2 shows the theoretical structural unit of the polymer, the logarithmic viscosity, and the physical properties of the molded product. The polyimides obtained had good moldability and excellent strength and heat resistance.

Comparative Example 1 In Example 1, 2,2-bis[:4-(4-aminophenoxy)phenyl]propane was replaced with 4,
Polymerization was carried out in substantially the same manner except that '-diaminodiphenyl ether was used to obtain a polymer having the following theoretical structural unit and having an logarithmic viscosity of 1.20 at the polyamic acid stage.

? ' Il OO An attempt was made to pelletize this polymer using Method 1 similar to Example 1, but the melt fluidity was poor, and the processing temperature was set at 400°C.
Even when the temperature was raised to ℃, homogeneously melted pellets could not be obtained.

Furthermore, if the temperature was lowered any further, the resin would decompose, so melt molding was ultimately impossible.

<Effects of the Invention> As is clear from the Examples and Comparative Examples, the thermoplastic polyimide of the present invention has good melt moldability and has the excellent mechanical strength and heat resistance inherent to polyimide. The injection molding method, which is flexible and has high molding productivity, can produce high-performance molded articles, so it is used as a heat-resistant material in the electrical and electronic equipment industry, the automobile industry, the office equipment industry, the aerospace industry, etc. Useful.

Patent applicant Higashi Shikikai Co., Ltd.

Claims (1)

[Claims] General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ The main constituent is the repeating unit represented by (I), and in concentrated sulfuric acid, at a concentration of 0.5 g/dl, and at a temperature of 30°C. A thermoplastic aromatic polyimide polymer having a logarithmic viscosity in the range of 0.2 to 5.0 dl/g as measured under the following conditions. (In the formula, X indicates -S-, -C-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼.)