KR930003372B1 - Process for production of aromatic polyamide pulp - Google Patents

Abstract

polymerizing the same mol amount of aromatic diamine and aromatic diacid chloride in the mixture solution of amide solvent and inorganic salt; spinning the liquid crystalline prepolymer in pre-gelled state into polymerization acclerating precipitant contg. 0.1-90 wt.% of tert-amine per amide solvent through an irregular cross-sectional spinneret i.e. +, Y or *; drying, heat-treating at 100-300 deg.C; and finally crushing. The pulp can be rapidly produced by controlling gelation and has excellent properties.

Description

Process for producing aromatic polyamide pulp

The present invention relates to a method for producing an aromatic polyamide pulp having excellent physical properties. More specifically, a liquid crystal prepolymer solution is prepared by reacting an aromatic diamine and an aromatic dieside chloride in an amide solvent in which a metal salt is dissolved. The present invention relates to a method for preparing aromatic polyamide pulp having excellent physical properties by inflow, spinning into a polymerization accelerator precipitant containing a tertiary amine, and then grinding it.

In the conventional method for preparing aromatic polyamide pulp, Japanese Patent Application No. 59-47694 says that pulp-like short fibers are obtained by stirring and precipitating a polymer solution dissolved in an organic solvent in water or alcohol, but the method uses a low molecular weight polymer. Since it can only be dissolved in an organic solvent, the physical properties are deteriorated, and US Pat. No. 4,511,623 is a method of polymerizing a tertiary amine by adding a tertiary amine to the amide polymerization solvent. Due to the polymerization rate, gelation occurs within a few seconds, so that process control is impossible, and even when gelation occurs, the molecular chains exhibit an isotropic property without orientation, and in order to prepare a polymer having excellent physical properties, it is required to be left for 5 hours or more.

The present invention solves the conventional problems as described above will be described below in detail the invention.

The present invention relates to amide solvents (N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide (DMAc), hexamethylphosphoimid (HMPA), N, N, N, N-tetramethyl Urea (TMU), N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc.} alone or a mixed solvent of these metal salts (CaCl ₂ , LiCl, NaCl, KCl, etc.) to 0.1 ~ Dissolve the amount of 20wt%. An aromatic diamine is added thereto to dissolve, and then an equimolar amount of aromatic dieside chloride to react with the aromatic diamine is added thereto to react at a low temperature to prepare an anisotropic liquid crystalline prepolymer solution. Then, the surface area is increased to increase the penetration effect of tertiary amines, and introduced into a spinning device having a non-circular, non-circular deformed hole to facilitate pulping, and then by 0.1 to 90 wt% of tertiary amines to the amide solvent. Aromatic polyamide pulp having the following repeating units of the following structural formula: It relates to a method of manufacturing.

In Formulas (I) and (II), R ₁ , R ₂ , and R ₃ are

또는

이다.R ₁ , R ₂ and R ₃ may be the same as or different from each other. X is H, Cl, Br, I or an alkyl or alkoxy group having 1 to 4 carbon atoms, Y is

or

to be.

In the present invention, the polymer content of the polymerization solvent is 5-30 wt%, the intrinsic viscosity of the prepared aromatic polyamide is 4.0 or more, and the specific surface area of the prepared pulp is 15 m 2 / g or more, and the specific surface area of the conventional kevlar pulp. Better than 9-11 m 2 / g (specific surface area was measured by ASTM C-699-79, a nitrogen adsorption method). When the specific surface area is large, the bonding strength with other materials increases when making a composite with other materials, thereby improving physical properties such as strength of the composite.

The present invention was able to significantly reduce the amount of the polymerization accelerator precipitant as compared to the method of introducing the conventional liquid crystal prepolymer into the pulping apparatus and simultaneously extruded and sprayed with the polymerization accelerator precipitant, and the specific surface area of the pulp prepared as described above It was much better than that produced by the method.

Example 1

After fully purifying the 2 L reactor with nitrogen to completely remove moisture, 27.0 g of calcium chloride was added to 1200 ml of NMP, and the temperature was raised to 80 ° C. to dissolve inorganic salts. Then, 24.5 g of 1,4-phenylene diamine was added and dissolved for 10 minutes. Let's do it. After the solution was lowered to about 5 ° C., 45.95 g of terephthaloyl chloride was added to react to prepare a liquid crystal prepolymer, which was then transferred to a spinning device having a Y-shaped mold, and polymerization of a mixed solvent of NMP 1000 ml, which is a polymerization solvent, and 2000 ml of pyridine, was carried out. The pulp was prepared by spinning and winding the accelerated precipitant, drying and heat-treating at 250 ° C. to the heat roller before winding, and then pulverizing with a refiner, a pulping apparatus. At this time, the intrinsic viscosity of the pulp was 5.3, and the specific surface area was 15 m 2 / g.

Example 2

The liquid crystal prepolymer prepared as in Example 1 was transferred to a spinning device having a + -shaped cap and spun on a polymerization accelerator precipitant, which is a mixed solvent of NMP 1500ml and pyridine 1500ml as a polymerization solvent, and at the same time 250 ° C in a thermal roller before winding. The pulp was prepared by drying, giving a heat treatment effect and then pulverizing with a refiner, a pulping apparatus. At this time, the intrinsic viscosity of the pulp was 5.8, and the specific surface area was 17 m 2 / g.

Example 3

형 방사구금을 사용하였다. 이때 펄프의 고유점도는 6.1이었으며, 비표면적은 18㎡/g이었다.Prepared as in Example 2

Type spinnerets were used. The intrinsic viscosity of the pulp was 6.1, and the specific surface area was 18 m 2 / g.

Example 4

Prepared as in Example 1, but transferred to a spinning device having a + -shaped detention, spinning and winding in a polymerization accelerator precipitant, a mixed solvent of NMP 500ml and pyridine 2500ml as a polymerization solvent, and drying at 100 ° C. in a heat roller before winding and heat treatment. After the effect was pulverized with a refiner, a pulping apparatus, pulp was prepared. At this time, the intrinsic viscosity of the pulp was 5.6, and the specific surface area was 16 m 2 / g.

Example 5

Prepared as in Example 3, but the temperature of the thermal roller was used as 300 ℃. The intrinsic viscosity of the pulp was 6.1, and the specific surface area was 17 m 2 / g.

Comparative Example 1

Prepared in the same manner as in Example 3, spinning and winding in a coagulation bath of 3000ml of water, and dried at 250 ℃ in the heat roller before the winding, giving a heat treatment effect and then pulverized in a refiner, a pulping apparatus to prepare a pulp. The intrinsic viscosity of the pulp was 2.5, and the specific surface area was 9 m 2 / g.

Comparative Example 2

Prepared as in Comparative Example 1, but was spun into a polymerization accelerator precipitant of NMP 3000ml as a polymerization solvent. At this time, the intrinsic viscosity of the pulp was 3.1 and the specific surface area was 8 m 2 / g.

Comparative Example 3

Prepared as in Comparative Example 1, but the heat roller was used at 90 ℃. The intrinsic viscosity of the pulp was 2.1, and the specific surface area was 9 m 2 / g.

Comparative Example 4

Prepared as in Comparative Example 3, but spun in a coagulation bath of 3000ml of pyridine. The intrinsic viscosity of the pulp was 5.6, and the specific surface area was 10 m 2 / g.

Claims (2)

In the mixed solution of an amide solvent and an inorganic salt, an equimolar amount of aromatic diamine and an aromatic dieside chloride are polymerized and spun through a spinneret, followed by grinding to prepare an aromatic polyamide pulp. An aromatic polyamide characterized in that the polymer is spun through a release cross-section into a polymerization accelerator precipitant containing 0.1 to 90 wt% of a tertiary amine relative to the amide solvent, and dried and heat-treated at a temperature of 100 ° C to 300 ° C before grinding. Method for producing pulp. The shape of the deformed cross section detention according to claim 1, wherein the shape of the deformed cross section is formed in the shape of +

Process for producing aromatic polyamide pulp, characterized in that the form.