JPS6245716A - Production of high-molecular weight para-oriented aromatic polyamide fiber - Google Patents

Abstract

PURPOSE:To obtain high-molecular weight para-oriented aromatic polyamide fibers, by extruding a liquid polymerization dope containing a para-oriented aromatic polyamide having a low polymerization degree dissolved therein into a fluid inert to acid halide groups and heating and/or stretch deforming the extruded dope. CONSTITUTION:A para-oriented aromatic dicarboxylic acid chloride is added to an amide type solvent expressed by formulas I-III [R1, R2 and R3 are CH3 or C2H5; R4 is (CH2)3, (CH2)4 or (CH2)5] containing an inorganic chloride expressed by the formula MCla (M is alkali metal or alkaline earth metal; a is 1 or 2) and a para-oriented aromatic diamine to give a liquid polymerization dope containing 5-10 para-oriented aromatic polyamide having etainh as follows; 1.80<=etainh<=3.00. The resultant liquid dope is then extruded into a fluid inert to acid halide group expressed by the formula -CX=0 (X is halogen) and subjected to heating and/or stretch deformation in the fluid to advance the polymerization reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to high molecular weight para-oriented aromatic iris 1! Concerning fiber manufacturing methods. More specifically, a liquid polymerization dope consisting of a Zera-oriented aromatic polyamide with a low degree of polymerization, chlorides of alkali metals and alkaline earth metals, and an amide-type solvent containing I (OR) produced as a by-product during polymerization is transferred from a spinneret. The present invention relates to a method for obtaining oriented aromatic poly-amyl 61 fibers of high molecular weight and ξ by increasing the degree of polymerization after extrusion.

Conventional technology In recent years, there has been a strong demand in the industry for organic polymer materials with high strength, high modulus, heat resistance, chemical resistance, and dimensional stability. Polymers such as V-hydrazine r1 polyamideimide are actively produced, and the resulting polymers are formed into fibers, films, etc., and used as various industrial materials.

As described above, para-oriented polyamide fibers are extremely useful due to their high strength, high modulus, heat resistance, and chemical resistance. However, in the case of elephant-oriented aromatic polyamides represented by d-tree p-phenylene terephthalamide (hereinafter abbreviated as PPTA), N-methyl-2-pyrrolidone (hereinafter referred to as NMP
After solution polymerization in an amide type solvent such as (abbreviated as ), the resulting polymer is neutralized, washed with water, dried, and once isolated, the +5 remer is dissolved in a solvent and fibers are formed by wet spinning. . However, since the polymer is difficult to dissolve in general-purpose organic solvents, it is extruded from a spinneret after being dissolved in concentrated sulfuric acid. In this way, polymerization and spinning are completely separated, and the use of large amounts of two types of solvents, amide chloride solvent in the polymerization system and concentrated sulfuric acid in the spinning system, is cost-effective.
It is disadvantageous. Further, concentrated sulfuric acid is diluted with water when washing the yarn after spinning, and it is very difficult to recover concentrated sulfuric acid from this.

As in the present invention, by directly spinning from liquid polymerization dope without separating polymerization and spinning, it is industrially easy, and the number of steps leading to fibers can be reduced, and the type and amount of solvent used can be reduced. It is very useful to reduce. - After polymerization, the PPTA obtained by separation is treated with calcium chloride,
A spinning method in which lithium chloride and lithium chloride are redissolved in an amide type solvent such as NMP or hexamethylphosphoformamide and used as a spinning dope to form a coagulating liquid such as hot water is described, for example, in Japanese Patent Publication Nos. 50-12485 and 12486. It is publicly known as described in Japanese Patent Publication No. 50-35941. However, PPT obtained by separation after polymerization
A is very difficult to dissolve in the solvent, and even if it dissolves, it has changed to the acid halide that should be the active terminal, so it no longer reacts with the amine group (-NH2), and the original P
The molecular weight cannot be larger than that of PTA.

Further, a spinning method in which a polymerized dope is directly used as a spinning dope to form a coagulating liquid such as water is also described, for example, in Japanese Patent Publication No. 50-124.
Publication No. 85, Publication No. 12486, Publication No. 50-35941
It is shown in the publication No. However, since para-oriented aromatic polyamide P such as PPTA is poorly soluble, when it is used as a polymer dope with a high degree of polymerization necessary to obtain sufficiently high fiber properties, the polymer dope becomes gel-like or Because it solidifies, it cannot be extracted as a continuous fiber when extruded. In addition, the degree of polymerization is low, and polymerization r-
Even if it is extruded as a polymer, the acid halide group, which should be the active end, changes to a carxyl group when it is introduced into the coagulating liquid, and no longer reacts with the amine group. Therefore, even if the degree of polymerization increases somewhat due to the shearing force when the polymerized P-p is extruded from the spinneret, there is a limit beyond which the polymer will not have a high molecular weight.

Problems to be Solved by the Invention The present invention provides high molecular weight para-oriented aromatic polyamide fibers,
The object of the present invention is to provide a method for obtaining a polymer directly from a polymerization dope, industrially easily, and with a small number of steps.

That is, in the present invention, in order to easily obtain a high molecular weight A-oriented aromatic polyamide fiber in a small number of steps, it is possible to obtain a high-molecular-weight A-oriented aromatic polyamide fiber from a liquid polymerization process in which a para-oriented aromatic polyamide with a low degree of polymerization, if IJ amide, is dissolved. By directly extruding it from a spinneret, introducing it into a fluid that is inert to acid halide groups so that the terminal acid/ride group remains active, and heating and/or elongating it in the fluid, The object is to obtain a high molecular weight, q-oriented aromatic polyamin fiber.

Means for Solving Problems The present invention provides para-oriented Extrusion into a fluid inert to polymerization activity containing a low polymerization degree polymer of para-oriented aromatic polyamide P obtained by adding aromatic radical I phosphate chloride, heating in the fluid and/or This is a method for producing high molecular weight para-oriented aromatic polyamide fibers, which is characterized by elongation and deformation to advance a polymerization reaction.

Here, M in the formula is selected from alkali metals and alkaline earth metals, a has a value of 1 or 2, and is determined by the valence of M. IJ, 112 + R3 are each -0H3.

-C2Hs, which may be the same or different, R4 is 1,000CH2, +0H2-)-; ÷O
H2 Selected from the large group. X is selected from halogen elements.

In the present invention, the liquid polymerization dope is 1.80≦ηinh
5-10% para-oriented aromatic polyamide with ≦3.00
and in which the terminal acid/ride groups of the polyamide remain as they are without losing their activity. Once quenched with H20 etc., the polymer is
In addition to being difficult to dissolve in the mold solvent, the terminal acid halide P group changes to calzenic acid and loses its activity, so the polymerization reaction no longer occurs, so the liquid polymerization dope obtained during polymerization is directly passed through the spinneret. Push it out.

Here, ηinh represents the intrinsic viscosity of the polymer and is defined by the following formula.

ηinh =Xn (?7r)/0 where ηr represents the relative viscosity and O represents the polymer concentration of 0.22 in 100 ml of solvent.

The relative viscosity ηr is determined by the time a dilute solution of the polymer flows through an Ostwald capillary viscometer divided by the time a pure solvent flows through the same viscometer. The dilute solution used to determine ηr has a concentration expressed by C above, the flow time is 30°C, and the solvent is concentrated sulfuric acid (98%).
is determined using

The liquid polymerized dope used in the present invention is a dope that exhibits optical anisotropy. This dope contains, for example, 0.84 mol of calcium chloride, 0.56 mol of p-phenylenediamine.
To a 20°C solution of 1.42 N-methyl-2-pyrrolidone containing
When d is added and stirred, optical anisotropy can be detected with the naked eye in about 10 minutes, and P-zo around this point is used as liquid polymerized P-zo.

The liquid polymerized P-p obtained as described above is extruded through a spinneret immediately after it is obtained. The P-P1,-)
r#:m ト1 l-1! ++n 4111
Jr Co-17L -”r r 17r
Thousand Δi? The rop is kept at a temperature below room temperature because it is no longer liquid and difficult to extrude through the spinneret. The temperature is preferably kept below 0°C. In addition, if the polymerization tank and spinning device are separated, liquid polymer P is transferred from the polymerization tank to the spinning device.
- It is also advisable to maintain the line through which the liquid is fed at the same temperature.

In the present invention, by extruding the liquid crystal r-zo exhibiting optical anisotropy from the spinneret, the molecular chains are oriented in the thread direction in the system due to the rigidity of the molecules of the oriented aromatic polyamide. By placing this thread in an acid halide group inert fluid, it remains oriented and remains with the activity of the acid halide P group. By heating it to an appropriate temperature,
The acid halide group at the end of the molecular chain can be vibrated and reacted with neighboring amino groups, and even the extremely low molecular weight polymers and unreacted monomers present in the system are moved to advance polymerization. Furthermore, by applying appropriate elongation deformation, the long molecular chains can be shifted, their active ends can react with each other, and the degree of polymerization can be increased.

In the present invention, a fluid that is inert to acid halide groups means a fluid that does not lose its polymerization activity by reacting with the acid halide P group that is the active terminal. Specifically, it is desirable that the material does not contain a large amount of a substance having active hydrogen such as water or alcohol. When the fluid is a gas, the content of the substance is preferably 0.03% by volume or less, and when the fluid is a liquid, the content of the substance is preferably 0.002% by weight or less. When using commercially available gases such as nitrogen, argon, helium, etc., the water content in these gases is 0.03% by volume or less. Although it can be used as is after taking it out of the chamber, when using liquids such as aliphatic hydrocarbons, aromatic hydrocarbons, and ketones, commercially available reagents contain water of 0.002% or more. For,
They are purified and dried using a purification method suitable for each compound. For example, aliphatic and aromatic hydrocarbons are
% by volume of concentrated sulfuric acid several times, washed with water, neutralized, dried with calcium chloride, etc.) By adding IJum and distilling, etc., obtain a liquid with a water content of 0.002% by weight or less. Can be done.

The acid halide group inert fluid used in the present invention is
Specifically, one or more gases selected from the group consisting of nitrogen, alzan, helium, or aliphatic hydrocarbons such as n-hexane, cyclohexane, heptane, octane, nonane, decane, and undecane; ,
After being heated and/or elongated in a gas or with one or more liquids selected from aromatic hydrocarbons such as toluene and xylene, acetone, cyclohexanone, acetophenone, and ketones such as benzophenone,
Gas,
Liquids may also be used together.

In the present invention, the dope extruded into the above-mentioned inert fluid needs to be heated and/or elongated. By heating and/or elongation deformation, end groups with polymerization activity (acid halide group and amino group)
This is because polymerization progresses by causing a reaction due to the vibration of molecular chains due to heating and/or displacement of long molecular chains due to elongation deformation, and the desired high molecular weight pan-oriented aromatic polyamide fiber can be obtained. be. The degree of heating at that time is preferably from 50℃ to 300℃, and 50℃
The following is not preferable because it takes a long time to achieve a sufficiently high degree of polymerization. Furthermore, temperatures of 300° C. or higher are not preferable because the fibers may be colored due to decomposition of the solvent or polymer. More preferably 100°C or higher, 300°C
The range is as follows.

Further, elongation deformation can usually be imparted by increasing the take-up speed relative to the linear speed during extrusion, and the degree of elongation deformation is usually in the range of 1 to 7. Although it may be more than this, excessive stretching may involve cutting of the fibers, which is not preferable.

Examples Example 1 N-
Methyl-2-pyrrolidone 500111! , 33.39 (0.3 moλ) of calcium chloride were added thereto, and the mixture was stirred at room temperature.

Once completely dissolved, p-phenylenediamine 21.6f
(0.2 mon) was added and stirred for about 40 minutes. This was cooled to -20° C. with stirring in a dry ice-ethylene glycol bath. When the temperature inside the system drops to 120℃, terephthaloyl chloride r40.6F (0.2m
ofl, ) was added in a fine powder state in about 10 seconds.

The temperature in the system rose to about 0° C. within a few seconds after the addition, and after stirring for 10 minutes in this state, a liquid polymerized P-p for spinning was obtained. (ηinh = 1.85) The liquid polymerization dope was passed through a Teflon tube and
The dope was fed into a plunger equipped with a monohole spinneret, and the dope was extruded from the spinneret into dry (moisture content: 10 ppm or less) n-hexane, and refluxed for 10 minutes. After that, the thread was taken out, washed with water and dried, ηinh =
2.70 threads were obtained.

Example 2 Liquid polymerized P-p obtained in the same manner as Example 1 was added to 0.5
Extrude from the spinneret of Shimaφ, 1.5mmφX40++r+
The mixture was poured into a small tube of N with dry n-hexane, and elongated and deformed by the flow of n-hexane. By washing the obtained thread with water and drying it, a thread having a ηinh of 3.55 was obtained.

Example 3 Liquid polymerization 1 obtained in the same manner as in Example 1;
It was extruded from a spinneret of 5 mφ, poured into small tubes of 1.5 mm diameter x 40 tubes together with heated (69° C.) dry n-hexane, and elongated and deformed by the heated n-hexane flow. By washing the obtained thread with water and drying it, η1nh=4. A thread of OO was obtained.

Example 4 Liquid polymerization r-p obtained in the same manner as in Example 1 was added to 0.5
It was extruded through a mmφ spinneret, poured into a small tube of 1.5 mmφ×40 mm along with heated (150° C.) and dried n-undecane, and elongated and deformed by the heated n-undecane flow. By washing the obtained yarn with water and drying it, ηinh=5.
71 threads were obtained.

Example 5 0.5% of the liquid polymerized P-zo obtained in the same manner as in Example 1
It was extruded from a wφ spinneret and ejected together with Alzan from a nozzle attached to the tip of the spinneret. At this time, the argon pressure is z
14/rrrm2. By washing the yarn thus obtained and drying it, a yarn with η1nb=-3.60 was obtained.

Example 6 A liquid polymerized rop obtained in the same manner as in Example 1 was extruded through a spindle with a diameter of 5 mm, and was spouted together with nitrogen gas through a nozzle attached to the tip of the spinneret.
℃) 1.5 pieces φX4 (h+m) with dry n-undecane
The tube was passed through a small tube and elongated and deformed by heating n-undecane. By washing the thus obtained thread with water and drying it, a thread with ηinh = 5 and 70 was obtained.

Example 7 Liquid polymerized P-zo obtained in the same manner as Example 1 was
It was extruded through a spinneret of ranφ, heated (250° C.) and poured into a small tube of 1.5 m + nφ x 40 m together with dried benzophenone, and elongated and deformed by the heated benzophenone.

The yarn thus obtained was passed through an acetone slag, a water bath, and a dryer, and then wound around a wine goo at a draft of ηr = 1 to obtain a yarn with ηinh = 5.00.

Comparative Example 1 The liquid polymerized r-p obtained in the same manner as in Example 1 was
It was extruded through a trmφ spinneret into hot water at 99°C, and then wound up at dr=1. When this thread is washed with water and dried, η
Inh = 1, 88 straight yarns were obtained.

Effects of the Invention According to the production method of the present invention, in order to perform spinning directly from liquid polymerized P-polymer, the polymerized high molecular weight polymer is further dissolved in concentrated sulfuric acid as in the case of the present invention, and then spun. This saves the effort twice, and furthermore, there is no need to use concentrated sulfuric acid, which is difficult to recover, for spinning. Furthermore, there is no corrosion of the equipment due to sulfuric acid, and long-term operation is possible. In the present invention, organic solvents such as aliphatic hydrocarbons, aromatic hydrocarbons, and ketones are newly used, and these are easy to recover, have good yields, and are easy to purify.

Claims (4)

[Claims] (1) There are general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas, etc. that include an inorganic chloride with the general formula MCl_a
There are tables, etc. ▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Para-oriented aromatic diamine is dissolved in one or more amide type solvents selected from the group consisting of By adding an acid halide, para-oriented aromatic polyamide is polymerized, and while the polymer dope remains liquid and has polymerization activity, the liquid polymer dope is directly added to the acid halide group (▲mathematical formula , chemical formula, table, etc. ▼) is extruded into an inert fluid and subjected to heating and/or elongation deformation in the fluid to further advance the polymerization reaction. Method for producing aromatic polyamide fiber In the general formula, M is selected from alkali metals and alkaline earth metals, a takes a value of 1 or 2, and is determined by the valence of M. R_1, R_2, R_3 are −CH_3, −, respectively
Selected from the group C_2H_5, R_4 is ■CH_2■
It is selected from the group consisting of _3, ■CH_2■_4, and ■CH_2■_5. Also, X is selected from halogen elements (2) The manufacturing method according to claim 1, wherein the liquid polymerization dope is a dope exhibiting optical anisotropy. (3) The manufacturing method according to claim 1, wherein the para-oriented aromatic polyamide in the liquid polymerization dope has an intrinsic viscosity ηinh of 1.80≦ηinh≦3.00. (4) The fluid inert to the acid halide group (▲There are mathematical formulas, chemical formulas, tables, etc.▼) is one or more gases selected from the group consisting of nitrogen, argon, helium, or n- Aliphatic hydrocarbons consisting of hexane, cyclohexane, heptane, octane, nonane, decane, undecane, aromatic hydrocarbons consisting of benzene, toluene, xylene, acetone, cyclohexanone, acetophenone,
The manufacturing method according to claim 1, wherein the liquid is one or more types selected from ketones consisting of benzophenone.