JPH0460491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wholly aromatic copolyesterimide fiber that has high strength, high modulus of elasticity, and extremely high heat resistance.

[Prior Art] In general, wholly aromatic polyester imides consisting of aromatic diamines and P-phenylene bistrimelitate dianhydride are known (US Pat. No. 3,355,427). Further, a wholly aromatic copolyesterimide consisting of an aromatic diamine, P-phenylene bistrimelitate dianhydride, and pyromellitic anhydride is also known (US Pat. No. 3,407,176). These US patent specifications also mention fibers and films as forms of molded products of the above polymers, but their characteristics are mostly limited to heat resistance, and there is no mention of molded products with excellent mechanical properties. . Fibers with high strength, high modulus, and excellent heat resistance have many uses and are particularly desirable, yet the above-mentioned U.S. patent specification does not mention this possibility at all. .

[Problems to be Solved by the Invention] As a result of intensive studies by the present inventors to obtain fibers having the above-mentioned properties using wholly aromatic esterimide polymers, the present inventors found that a specific aromatic diamine or a mixture containing the same was found. The inventors have discovered that a wholly aromatic copolyesterimide consisting of a diamine, P-phenylene bistrimelitate dianhydride, and pyromellitic anhydride is suitable for this purpose, and has arrived at the present invention.

[Means to solve the problem] The present invention has the following configuration.

The diamine component consists of 2-chloro-P-phenylenediamine (A) or the 2-chloro-P-phenylenediamine (A) and P-phenylenediamine, and the acid anhydride component consists of P-phenylenebistrimeryl. It consists of a fully aromatic copolyesterimide consisting of tate dianhydride (B) and pyromellitic anhydride, and the ratio of (A) in the diamine is 50 to 100 mol%, and the ratio of (B) in the acid anhydride is It is a wholly aromatic copolyesterimide fiber characterized by having a content of 20 to 80 mol%.

[Effect] The present invention will be explained in more detail below.

The fibers of the present invention are produced by polymerizing polyamic acid as a precursor polymer in an amide solvent, wet-spinning this solution, and then cyclizing it into imide groups using an appropriate means. The diamine to be subjected to polymerization is 2-chloro-P-phenylenediamine (A) or a mixture of (A) and P-phenylenediamine.
The proportion of (A) is 50 to 100 mol%. Further, the acid anhydride component is a mixture of P-phenylene bistrimelitate dianhydride (B) and pyromellitic anhydride, and the ratio of (B) in the acid anhydride component is 20 to 80 mol%. In order to obtain high-performance fibers, it is necessary to use monomers with diamines and acid anhydrides in the above-mentioned ratios, and polymers outside the above-mentioned ranges, such as homopolymers of each, do not produce high-performance fibers, as shown in the comparative example. fibers cannot be obtained.

The monomers used in the present invention are as described above, but up to about 10 mole percent of other monomers may be copolymerized. Such copolymerizable components include diamines such as m-phenylenediamine, 4,4'-diaminodiphenyl ether, and 3,4'-diaminodiphenyl ether. In addition, examples of acid anhydride components include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, etc. .

Examples of amide solvents used in polymerization include N-methylpyrrolidone (NMP), N,N-dimethylacetamide, and N,N-dimethylformamide.

The polyamic acid solution thus obtained is used for spinning.

The stock solution used in the wet method may be the above-mentioned polyamic acid solution itself, but the present inventors first proposed a patent application filed in 1983.
−27068, that is, using a partially cyclized polymer solution in which a part of the amic acid units are imidized in solution by adding a cyclizing agent such as acetic anhydride is preferable for transparent void-free coagulation. It may be more preferable to provide yarn. The above polyamic acid solution or partially cyclized polyamic acid solution is extruded into an aqueous coagulation bath through an orifice and spun. The coagulated thread may subsequently be drawn. The undrawn or drawn coagulated yarn is either dried as it is and subjected to thermal cyclization, or treated with a reducing agent while swollen to be chemically imidized. As the cyclizing agent used in the latter case, aliphatic acid anhydrides such as acetic anhydride and propionic anhydride are suitable. Further, in this chemical cyclization, an organic base such as pyridine or quinoline is usually used as a catalyst. The chemical cyclization treatment conditions are a temperature of 15 to 50°C and a treatment time of 10 minutes to 1 day or more. The chemically cyclized yarn is then dried, but before that, it may be washed with an organic solvent to extract and remove the cyclizing agent. Suitable cleaning agents include toluene, dioxane, and chloroform.

The above chemically cyclized or non-chemically cyclized yarn is then dried and finally subjected to hot drawing or heat treatment. In the yarn that has not been chemically cyclized, the amic acid is thermally cyclized into an imide group in this step.
Fibers that have not been drawn at the polyamic acid stage must be drawn at this step. Further, as a heating means, a hot plate, a hot roll, a heating cylinder, etc. may be used for continuous processing, or the material may be heat-processed in batches while being wound around a bobbin or drum. Further, hot stretching or heat treatment may be carried out by raising the temperature stepwise, and the final treatment temperature is preferably 400°C or higher. The atmosphere is air or an inert gas such as nitrogen.

[Example] The present invention will be explained in more detail with the following Examples and Comparative Examples.

In addition, the intrinsic viscosity (ηinh) of the polyamic acid in the example
So that the ratio is 0.5g of polymer/100ml of NMP,
The polymerization solution was diluted with NMP and measured at 25°C.

In addition, the tensile properties were measured using Tensilon manufactured by Toyo Baldwin Co., Ltd., with a test length of 100 mm and a tensile speed of 10 mm/min.
Measured under the following conditions.

Example 1 In this example, the diamine component was 2-chloro-P-
Results of spinning a copolyesterimide that is phenylene diamine (cl-P) and whose acid anhydride components are 60 mol% of P-phenylene bistrimelitate dianhydride (TmHTm) and 40 mol% of pyromellitic anhydride (PMDA). (chemical cyclization method).

Dissolve 4.848 g (34 mmol) of cl-P in 69 ml of dehydrated NMP, cool in a 20°C water bath, and add 9.397 g (20.5 mmol) of TmHTm while stirring vigorously.
After adding 2.981 g (13.7 mmol) of PMDA powder mixture and continuing polymerization for 5 hours, diluted with 37 ml of NMP, a polyamic acid solution with a polymer concentration of 14%, ηinh 1.89, and solution viscosity of 1620 poise (25°C) I got it.

Pour this solution through a 6-hole cap with a diameter of 0.08 mm.
It was spun in a coagulation bath of NMP/water (volume ratio 25/75) at 25°C (spinning speed 13 m/min) and then stretched 1.8 times in water at 25°C. This coagulated thread, wound around a glass bobbin, was immediately immersed in acetic anhydride/pyridine (volume ratio 70/30) and left overnight at room temperature to convert the amic acid units into imide groups. After soaking this chemically cyclized thread in toluene at room temperature for 1 hour,
Vacuum dried at ℃. Then, using a 30 cm long glass cylindrical tube through which nitrogen was loosely passed, it was heated at 450 °C.
Stretched 2.2 times (yarn feeding speed 3.0m/min) and further
Tension heat treatment was performed at 500℃. The quality of the obtained fiber is
It had extremely high performance with a single yarn fineness of 2.6 d, strength of 20.9 g/d, elongation of 1.6%, and elastic modulus of 1350 g/d.

Example 2 In this example, cl-P/TmHTm]PMDA
The results of the chemical cyclization method of copolyesterimide (100/30/70) are shown.

Cl-P, TmHTm and PMDA were reacted at the above molar ratio in NMP, and the polymer concentration was 20%.
A polyamic acid solution with ηinh of 1.85 was prepared, and then 0.2 equivalents of amic acid units of acetic anhydride and pyridine, and an appropriate amount of NMP were added to obtain a partially cyclized polymer solution with a polymer concentration of 14% (2880 poise).

This solution was wet-spun, chemically cyclized, dried, and then hot-stretched at 550° C. to a size of 1.4 times using almost the same recipe as in Example 1. This fiber has a single yarn fineness of 5.2d and a strength of 14.8.
g/d, elongation 1.5%, and elastic modulus 1110 g/d.

Example 3 This example describes the use of cl-P/P-phenylenediamine.
The results of spinning (chemical cyclization method) of (P)/TmHTm/PMDA (70/30/60/40) copolyesterimide are shown.

In NMP, cl-P, P, TmHTm and PMDA
were reacted at the above molar ratio, the polymer concentration was 14%,
A polyamic acid solution with ηinh of 1.62 was obtained. This solution was subjected to wet spinning, chemical cyclization, and
After drying, it was stretched 1.8 times at 475°C and further subjected to tension heat treatment at 500°C. The yarn quality of the obtained fiber is single yarn fineness.
3.2d, strength 16.4g/d, elongation 1.3%, elastic modulus 1280
It was g/d.

Comparative Example 1 This comparative example shows the results of spinning a homopolyesterimide (chemical cyclization method) consisting of P and TmHTm.

P and TmHTm were polymerized in NMP to obtain a polyamic acid solution with a polymer concentration of 12%, 7 inch h2.03, and a solution viscosity of 1080 poise. This solution was wet-spun using the same recipe as in Example 1, and then chemically cyclized and dried.
It was stretched 1.8 times at ℃. The obtained hot drawn yarn had a single yarn fineness of 3.8 d, a strength of 12.6 g/d, an elongation of 0.9%, and an elastic modulus of 1420 g/d, and although the elastic modulus was high, the strength was lower than that of the fiber of the example. .

Comparative Example 2 This comparative example shows the results of spinning a homopolyesterimide made of Cl-P and TmHTm (chemical cyclization method).

In NMP, Cl-P and TmHTm were polymerized to prepare a polyamic acid solution with a polymer concentration of 17% and ηinh of 0.99, which was wet-spun using the same recipe as in Example 1, chemically cyclized,
After drying, it was stretched 1.8 times at 425°C, and then stretched at 475°C.
The material was subjected to tension heat treatment. The quality of the obtained fibers is a single yarn fineness of 3.4 d, strength of 12.2 g/d, elongation of 1.2%, and elastic modulus of 1060.
It was g/d.

[Effect of the invention] Taking the fiber as an example, the wholly aromatic copolyesterimide fiber of the present invention has a strength of 14 g/d or more and an elastic modulus of 14 g/d or more.
Extremely high performance with over 1000g/d, heat resistance,
It also has excellent dimensional stability and chemical resistance. Therefore, it is useful for many uses, such as reinforcing rubber, resin, etc., and heat-resistant electrical insulation.

Claims (1)

[Claims] 1 The diamine component consists of 2-chloro-P-phenylenediamine (A) or the 2-chloro-P-phenylenediamine (A) and P-phenylenediamine, and the acid anhydride component consists of P-phenylenebistrimeryl. It consists of a fully aromatic copolyesterimide consisting of tate dianhydride (B) and pyromellitic anhydride, and the ratio of (A) in the diamine is 50 to 100 mol%, and the ratio of (B) in the acid anhydride is A wholly aromatic copolyesterimide fiber characterized by having a content of 20 to 80 mol%.