JPS6392649A - Production of poly-p-phenyleneterephthalamide molding - Google Patents

Abstract

PURPOSE:To obtain a molded product having excellent mechanical properties, dimensional stability against moisture absorption, etc., by using a poly-p- phenyleneterephthalamide in which terminal amino and terminal carboxyl groups are substituted by hydrophobic substituents and which has specified properties, as a molding material. CONSTITUTION:In producing a poly-p-phenyleneterephthalamide by polymerizing terephthaloyl dichloride with p-phenylenediamine, a predetermined amount of a compd. reactive with the amines or carboxylic acid chlorides (e.g., aniline) is added, thus obtaining a poly-p-phenyleneterephthalamide having a etainh of not lower than 3, an apparent density of not higher than 1.38g/cm<3>, a terminal amino group content of not higher than 80-10X(etainh) milliequivalents/kg and a terminal carboxyl group content of not higher than 80-10X(etainh) milliequivalents/kg. The title molded product is prepd. from an optically anisotropic dope composed of said polymer and conc. sulfuric acid.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing an improved polyparaphenylene terephthalamide (hereinafter abbreviated as PPTA) molded product, and more specifically, The present invention relates to a method for manufacturing a PPTA molded product that has both mechanical properties and a low rate of dimensional change upon absorption of moisture.

[Conventional technology]

PPTA, which is obtained by polymerizing terephthalic acid dichloride (hereinafter abbreviated as TPO) and paraphenylenediamine (hereinafter abbreviated as PDA), has a rigid and straight molecular skeleton, so it produces molded products with excellent mechanical properties. It has been predicted for a long time that this would happen, and it was actually
0-8474) and Blaze (Japanese Unexamined Patent Publication No. 47-394)
Since a method for producing high-strength fibers was disclosed by Patent Publication No. 58), PPTA fibers have attracted particular attention in recent years as industrial materials for tire cords and FRP reinforcement materials due to their excellent mechanical properties and heat resistance. . Virtual PPTA film is attracting attention as a promising material in industrial fields that require high mechanical properties, such as base films for magnetic tapes, and several methods for producing PPTA film have been disclosed (for example, Publication No. 57-17886).

However, PPTA undergoes amide condensation produced by dehydrochloric acid condensation of monomers, and amine terminal groups and forces A/? Because it has hydrophilic groups such as phosphoric acid terminal groups, it easily absorbs moisture, and therefore its dimensions change due to moisture absorption.
This results in disadvantages such as a decrease in strength and elastic modulus, and fluctuations in electrical properties.

[Problem that the invention seeks to solve]

The purpose of the present invention is to eliminate the above-mentioned drawbacks due to moisture absorption without impairing the moldability or the mechanical and thermal properties of the resulting molded product, and to achieve excellent dimensions even under harsh conditions of high temperature and humidity. PPT with both stability and mechanical and electrical properties
A: We are trying to provide molded products.

[Means for solving problems]

As mentioned above, PPTA obtained by polymerizing TPC and PDA has molecular chain ends consisting of amine end groups and carboxylic acid end groups. Richi K continues to study the relationship with the ratio, that is, the rate of dimensional change due to moisture absorption, and the unit weight? We discovered the surprising phenomenon that as the amount of amine and carboxylic acid end groups per remer decreases, the rate of dimensional change due to moisture absorption decreases.
As a result of further intensive research, the present invention was completed.

Specifically, the present invention provides that when molding an optically anisotropic dogu made of PPTA and concentrated sulfuric acid, ηinh is 3.0 or more, the apparent density is 1.38 g/cm3 or less, and the amine end group is is less than 80-10X (ηinh) milliequivalents/kg, and the carboxylic acid terminal group is 80-IQ
The present invention provides a method for producing a PPTA molded article, characterized by using PPTA having a weight of X(ηinh) milliequivalents/kg or less.

As in the present invention, when PPTA with few amine end groups and carboxylic acid end groups is prepared by reaction of PDA and TPO using a so-called low-temperature solution polymerization method, TPO, which is reactive with amine or carboxylic acid chloride, P.D.
It can be produced by adding one or more substances other than A and reacting with the terminal amine or terminal carboxylic acid chloride to block the molecular chain ends.

The substance to be added may be any substance as long as it is reactive with the amine or carboxylic acid chloride as described above.
Not particularly limited. Examples of substances to be added include aniline, 0-lm- or p-chloroaniline, o-lm-
- or p-) luidine, o-lm- or p-nitroaniline, α- or β-naphthylamine, 2-
%3-Modi<4-biphenylamine, ethylamine,
Monoclass amines such as globilamine, inglobilamine, and cyclohexylamine, secondary monoamines such as N-methylaniline, diethylamine, and piperidine, or benzoyl chloride.

o"', m- or p-) luoyl chlorite 9, propionyl chloride, monocarboxylic acid chloride such as cyclohexane carbonyl chloride, or phenyl incyanate, ethyl isocyanate, phenyl isothiocyanate, ethyl isothiocyanate, etc. In order to make the effect of such terminal blocking even more remarkable, it is also possible to use, for example, a compound in which one or more of the hydrogen atoms in the above compound is replaced with fluorine. This is an embodiment.

Furthermore, there are no particular limitations on the method of adding and reacting these substances. Alternatively, the polymer once polymerized may be impregnated with the polymer in a suitable solvent and reacted with the polymer.

A specific example of a method for producing the polymer used in the present invention is shown below. However, it goes without saying that the method for producing the polymer (polymerization method) of the present invention is not limited to the method shown below.

Polymerization is most easily carried out by a so-called low-temperature solution polymerization method in which TPO and PDA are stirred and mixed in an amide solvent. As a solvent for polymerization, N-methylpyrrolidone,
Used are N,N-dimethylacetamide, N-acetylpyrrolidine, tetramethylurea, hexamethylphosphoramide, etc., or mixtures thereof in arbitrary proportions, or mixtures of these with lithium chloride, calcium chloride, etc. The monomer concentration during polymerization is approximately 0.1 to 160 mol/
It is l. In the conventional PPTA polymerization method, TPO and PDA are charged in a ratio of approximately 1:1 and mixed by stirring in the solvent, but special measures are required to obtain the polymer of the present invention. For example, if the molar balance between TPC and PDA is adjusted such that TPO is in excess, PDA is 1
00, TPC is preferably about 100.1 to 101. This is because if the molar balance is disturbed too much, the molecular weight cannot be made sufficiently high. ),
At the time of monomer charging, one or more of the monoamines described above are added such that the overall ratio of amino groups to carboxylic acid chloride groups is approximately 1:1. As a result, the carboxylic acid ends are blocked, and compared to polymers obtained by conventional methods, P has fewer amine and carboxylic acid ends.
PTA can be obtained. While roaring, TPO and PD
It is also possible to reverse the molar balance of A and use a monocarboxylic acid chloride compound or the like as an end-blocking agent.

The amount of end-capping agent added is determined by adjusting the amount of TPC (or PD) to equalize the molar balance between acid chloride groups and amino groups.
A) 0.1 to 1.0 is appropriate for 100. Also, in the polymer obtained by polymerization, what is the ratio of terminal groups to all monomers?

When ηinh is 3.0, it is approximately 0.7%, and when ηlnh is 5.0, it is approximately 0.5%, so from this reason as well, the above ratio is appropriate.

It is also possible to add a sealant and cause the reaction to occur once the polymerization has progressed to some extent. As polymerization progresses.

The PPTA produced may precipitate from the solvent,
In this case, the reaction with the sealant is a heterogeneous reaction. Therefore, when adding a sealant during polymerization, the amount of sealant should be adjusted to increase the probability of reaction between the sealant and the amino group (or carboxylic acid chloride group) and to perform effective sealing. It is good to have too much. Preferably, the amount is 05 to 10 times the amount necessary to equalize the molar balance between the amino group and the carboxylic acid chloride group. However, if it is used in excess, it is not preferable because it inhibits the progress of subsequent polymerization.

The polymerization temperature is selected between about -30°C and 100°C. Further, during polymerization, it is preferable to stir the entire system, and more preferably to continue stirring even after the polymer has solidified until the final degree of polymerization is reached.

The polymer that has reached the final degree of polymerization is transferred to, for example, a Henschel mixer, pulverized by adding approximately the same amount of water, washed several times with water, centrifuged from door to door, dried, and finally Obtained as a pale yellow polymer.

As a special method for producing PPTA of the present invention, a polymer polymerized in the same manner as before is isolated, and then reacted with monoincyanate, monocardenoyl chloride, monoaliphatic amine, etc. in a solid phase to perform end-blocking. is also possible.

In the present invention, when actually molding, a known method for molding PPTA, ie, a method for molding an optically anisotropic dope made of PPTA and concentrated sulfuric acid, etc., can be used.

In addition to sulfuric acid, chlorosulfuric acid, fluorosulfuric acid, or a mixture thereof can be used as the solvent for preparing Dogue, but from the viewpoint of solubility, concentrated sulfuric acid of 96 weight or more is preferable. The polymer concentration is at room temperature or higher;
The concentration is higher than that exhibiting optical anisotropy. Specifically, about 10
．． i amount% or more, preferably 15 times i4 or more. This is because a molded article made from an optically isotropic dope generally has a low density and low strength, making it difficult to exhibit the high mechanical properties inherent to PPTA. Dogu with such a poly-strengthening concentration often needs to be slightly warmed so that it can flow and be molded, but the higher the temperature, the faster the rate of deterioration, so dope in the range of room temperature to 100°C is usually used. is used.

Dogue may also contain conventional additives such as antioxidants and ultraviolet stabilizers.

In producing PPTA fibers from such dope, for example, the method described in Japanese Patent Application Laid-Open No. 47-39458 can be used.

In addition, regarding the production of PPTA film, for example,
The method disclosed in Japanese Patent Publication No. 57-17886 can be used, but the method is not limited thereto.

The molded product referred to in the present invention is not limited to the above-mentioned so-called long fibers or films, but is formed from a dogu through a die of a specific shape. For example, short fibers, hollow fibers,
This includes all fibril-like substances and rope-like substances.

[Action of the invention]

If the degree of polymerization of PPTA used in the present invention is too low, P
Since it is no longer possible to obtain a bottom-shaped product that exhibits the excellent mechanical properties inherent to PTA, a polymer having a degree of polymerization that provides a logarithmic viscosity ('71nh) of 3.0 or more, preferably 3.5 or more is usually selected.

The polymer used in the present invention is 1.38 g/cI
It has a density of n3 or less, preferably 1.36 g/3 or less. Polymers with high density generally have high crystallinity, and such polymers have poor solubility in concentrated sulfuric acid when preparing dough, resulting in non-uniform dough, undissolved polymer remaining, and dissolution. As the time required for this process increases, the degree of decrease in molecular weight increases due to decomposition of the polymer, which adversely affects the moldability and physical properties of the molded product, which is undesirable.

At the same time, the polymer used in the present invention must satisfy the following conditions. That is, the amount of amine end groups is 80-10X (ηinh) milliequivalents/kI!
or less (preferably 7O-10X(ηinh) mm/-1
t/ni! 9 or less) and the amount of carboxylic acid end groups is 80-10
It must be less than X(ηinh) milliequivalents/kli+ (preferably less than 7O-10X(ηinh) milliequivalents/kg). The hygroscopicity of a PPTA molded product has a close relationship with the amount of end groups, and if a polymer with an amount of end groups outside this range is used, the hygroscopicity of the resulting molded product cannot be sufficiently reduced. Therefore, mechanical properties tend to deteriorate and electrical properties such as electrical insulation properties tend to fluctuate. Although the reason for the decrease in hygroscopicity due to the decrease in the amount of amine and carboxylic acid terminal groups is not clear, it can be considered as follows. How is PPTA used for polymer moldings?
However, it is not completely crystalline, and amorphous parts grow to some extent, and it is thought that most of the molecular chain ends exist in these amorphous parts. On the other hand, when moisture infiltrates into the molded product, it is selectively taken in from the amorphous portion.

Therefore, it is thought that hygroscopicity decreases due to a decrease in polar end groups that have a strong affinity for water. Therefore, the next molded product obtained by the method of the present invention is
It is also effective and a preferred embodiment to make it even more difficult to absorb moisture by heat treating it within a range where f- does not deteriorate.

By the way, the total amount of end groups in a given weight of polymer is inversely proportional to the number average molecular weight of that polymer, and P
The relationship between the viscosity of a concentrated sulfuric acid solution of PTA and its number average molecular weight has been studied and clarified by several researchers (for example, Arpin, M.).

Di Macromorphres Chemie, Volume 177.

No. 581 (1976)). According to that knowledge, TPO
When PDA and PDA are polymerized stoichiometrically, when ηinh is 5, the number average molecular weight is approximately 20,000, and 2
There are 2 end groups in 0000 g of polymer. In other words, there is approximately 100 miI in 1 kg of polymer.
J equivalents of end groups are present, and if the monomer charge is perfectly balanced and there are no other termination reactions, 50
There should be milliequivalents of each amine and carboxylic acid end group.

When ηinh is 6, the number average molecular weight is approximately 24
000, there will be approximately 40 millimeters of amine and carboxylic acid end groups present in polymer 1. Comparing these numbers, it is clear that the polymer used in the present invention has a very small amount of both amine and carboxylic acid end groups.

Although studies have been made on the composition of TPO and PDA in relation to PPTA polymer production technology, the focus of these efforts has been on increasing the molecular weight of the resulting polymer, and the charging ratio of TPC and PDA has not been adjusted. It is only a matter of making changes, and there are almost no examples in which attention is paid to the terminal groups of the molecular chain. Although a spinning method has been disclosed in which the molar balance of TPC and PDA during polymerization is manipulated and a polymer with an excessively large number of amine end groups is used (US Pat. No. 3,933).
No. 963), this is also intended only to improve spinnability, but there is no precedent for technology that attempts to improve the physical properties of molded products by actively manipulating the molecular chain terminal groups as in the present invention. Moreover, the PPTA polymer used in the present invention cannot be obtained by these known techniques.

〔Example〕

The invention will be further illustrated by the following examples. It goes without saying that these examples are illustrative of the invention and are not intended to limit it.

Moreover, parts mean parts by weight.

Next, a method for quantifying terminal groups in the present invention will be explained.

Amine end group determination method Dried polymer 0.21! Weigh the mixture into a 200 g capacity flat-bottomed flask and add 25 g of ion-exchanged water.

Add to this 0.21 sodium bicarbonate and 251 ethanol.
117 and an additional 1.25 Da of 1-fluoro-2°4
- Add dinitrobenzene. A Dimroth condenser was attached to the flask, and the contents of the flask were stirred with a magnetic stirrer and kept at 80°C for 4 hours in a water bath.
Reflux for an hour. Remove the reddish-brown colored polymer and wash thoroughly with acetone. The polymer was then heated at 80°C for 4
Dry under reduced pressure for an hour. The polymer thus obtained is 0.02
5. ! 5011 li+! Add 25 d of methanesulfonic acid to a beaker and stir with a magnetic stirrer at room temperature until completely dissolved. At this time, seal the mouth of the beaker with a suitable sealant and keep it out of light as much as possible during the melting process. This is because the dinitrobenzene group has high photoreactivity and to avoid darkening due to exposure to light. The transmittance of this solution at a wavelength of 430 nm is measured using a spectrophotometer (the device used by the present inventors is an absorption photometer model 6B manufactured by Hirama Rika Kenkyusho) using a quartz cell with an optical path length of 1 cIn. At this time, the amount of amine end groups per gram of polymer 1 is given by logTO/TI X 10' milliequivalent/kg. However, To is the untreated PPTA O,025, when the transmittance of methanesulfonic acid is ioog. It is the transmittance of a solution of ir dissolved in 2.5 ml of methanesulfonic acid, and T1
is the transmittance of a methanesulfonic acid solution of PPTA treated as described above, when the transmittance of methanesulfonic acid is taken as a factor of 100, and ε is the molar absorption of dinitrobenzene groups measured using the following model compound. The coefficient is 7100 (J/m
ot-crn).

Below is a method for quantifying the margin carboxylic acid end groups.In quantifying the carboxylic acid end groups, first wash the polymer thoroughly with water to make sure that no free acid or alkali remains in the polymer. For that purpose, 1. N I
J Mama - Disperse in a suitable amount of water, heat and stir at about 50°C, and after dispersing the polymer from door to door, the solution F may be titrated with an alkali or acid such as caustic acid or dinic acid. The washed polymer is thoroughly dried, and the carboxylic acid end groups are quantified by the following method.

Weigh 0.2 g of the dried polymer into a flat bottom flask,
10 Add 25 d of normal hydroxide solution (water-ethanol 1:1 weight ratio solution).

A Dimroth condenser was attached to this flask, and the mixture was refluxed for 4 hours in a water bath kept at 80°C while stirring with a magnetic starmer. The polymer was washed from door to door with a small amount of ethanol, and this washing solution was combined with the previous solution.
- Titrate with 3N aqueous hydrochloric acid solution. The amount of 10-3 normal hydrochloric acid aqueous solution required for neutralization at this time is defined as V1go. Further, in the same procedure, 10-3 N hydroxide)+Jum solution was refluxed and then titrated with 10N hydrochloric acid aqueous solution to determine the desired carboxylic acid terminal, which was characterized by the amount of hydrochloric acid aqueous solution required for neutralization. The base weight is 1 kgs b of polymer. Incidentally, the entire process for quantifying the carboxylic acid terminal group is carried out in an inert gas atmosphere in order to avoid absorption of carbon dioxide gas from the atmosphere.

Further, the logarithmic viscosity number (ηinh) is defined as follows.

In the formula, ηreL is a polymer solution (96 dw sulfuric acid 100 d
0.5 IPPTA) and pure solvent, measured using a capillary viscometer at 25°C.

Margins below Example 1 70 parts of calcium chloride was dissolved in 1000 parts of N-methylpyrrolidone in a polymerization tank having a high-speed rotating stirring blade, an inlet and an inlet for dry nitrogen, and an inlet for raw materials, and then PDA44.2
(equivalent to 1.90.4 moles of solvent) and 0.9 parts of sweetfish.
4 parts (equivalent to 1 molti to PDA) were dissolved. -2℃
After cooling to
(equivalent to 1 molti) was added all at once in a molten state. After 3 minutes, the polymer solidified into a cheese-like shape, so the polymerization reaction product was immediately transferred to a twin-screw closed kneader, and pulverized and subjected to shearing force in the same kneader for 20 minutes. Next, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, and the mixture was further pulverized, filtered, washed several times with hot water, and dried in hot air at 110°C. As a result, 95 parts of pale yellow PPTA with an ηInh of 4.3 and an apparent density of 1.35 μm was obtained.

The results of measuring the amount of terminal groups using the method described above were as follows.

Amount of amine terminal group: 31.3 mm equivalent/Amount of acid terminal group: 25.9 mmJ equivalent/yum Next, using this primer, a film was formed by the following method.

99.6 sulfuric acid 88 in 4 rubble flasks of 500m
1 part, and 12 parts of the above polymer was divided into two parts.
It took a total of 40 minutes to add the dope while stirring (at room temperature).After stirring was continued for 10 minutes, the temperature was raised to 60°C and defoaming was performed for 5 hours to prepare an optically anisotropic dope.

This dope was placed on a glass plate previously heated to 120'GK, and a film was formed manually using an applicator having a 0.10 slit. This was immediately placed in hot air maintained at 120° C., and left to stand for 10 minutes to perform isotropic treatment based on optical anisotropy. Thereafter, the film was immersed together with the glass plate in pure water, and the film was deoxidized and peeled off. This wet film was sandwiched between metal frames and dried in hot air at 2500G for 1 hour to obtain a yellow transparent film with a thickness of 25 μm.

The moisture absorption dimensional change rate of the obtained film was measured by the following method.

After drying the sample at 100°C under a nitrogen stream and cooling it to room temperature,
The elongation of the sample was measured using TMA (thermomechanical measuring device, TMA-30 manufactured by Shimadzu Corporation) in an atmosphere with a relative humidity of 85 cm, and was calculated using the following formula.

Moisture absorption dimensional change rate (■/Tsubasa, ChiRH) The size of the sample at the time of measurement was 2 pieces in width and 8 pieces in effective grip distance.

As a result, the moisture absorption dimensional change rate of the above film was 3.9 x 10 v1n/m in the longitudinal direction, %Fp, 6.5 x 10" m/am in the width direction, %R
It was H.

Example 2 The same primer as in Example 1 was added at a ratio of 12 parts to 88 parts of 99.7% sulfuric acid to prepare an optically anisotropic dope at 65°C. A 1.5 m long curved pipe from the dope tank to the die via the gear pump was maintained at 65°C and 0.1BX
300$ From a gui with 121 slits to a mirror-polished tantalum belt, the pulling speed is 2 tn.
Cast at a speed of 7 minutes, relative humidity 73%, temperature 36°C
After being exposed to the air for 60 seconds and becoming transparent,
It was coagulated in water at 10°C. This coagulated film was washed overnight with water at room temperature and then dried for 1 hour with hot air at 250°C to obtain a transparent yellow film with a thickness of 20 μm. Table 1 shows the physical properties of the obtained film.

Comparative Example 1 In a polymerization tank, 70 parts of calcium chloride was dissolved in 1000 parts of N-methylpyrrolidone, and then 44.2 parts of PDA (
Solvent 11 (equivalent to 0.4 mol) was dissolved. After cooling to -2°C, 85.1 part of TPO (equivalent to 1 io of solvent, 4 moles) was added to -2°C, and then polymerization was carried out under the same conditions as in Example 1 until ηinh was 4. .6, apparent density 1.35? /an'' pale yellow PPTA was obtained.

The amount of terminal groups of the obtained polymer was as follows.

Amount of amine end groups: 47.3 milliequivalents/Amount of carboxylic acid end groups: 35.91 equivalents/A film was prepared in the same manner as in Example 1 using this polymer, and the dimensional change rate upon moisture absorption was measured. The following results showed that the dimensional stability was inferior to that of Example 1.

Longitudinal direction 9. OX 10-5 z/mx,
Chi RH width direction 10.8 x 10 mx/
ax, %RH Comparative Example 2 Using the same polymerization method as shown in Comparative Example 1, ηlnh was 5.
78. Pale yellow PP with apparent density 1.37 y-i3
I got a TA. The 4+ and 1-mer terminal base layers each had the following: Amount of amine end groups: 40.5 milliequivalents, Ag: Caldic acid end groups: 32.11 equivalents/yield.

This primer was added at a ratio of 12 parts to 100 parts of 99.4% by weight sulfuric acid to obtain an optically anisotropic dogu at 65°C.

A film was formed from this dope under the same conditions as in Example 2 to obtain a yellow transparent film with a thickness of 15 μm.

Table 1 shows the physical properties of the obtained film.

Example 3 The same polymer as in Example 1 was mixed with 99.7% by weight sulfuric acid at 80%.
A dope exhibiting optical anisotropy at 70° C. was prepared by gradually dissolving 1 part to 19.3 parts. The piping from the dope tank through the gear pump to the spinneret (hole diameter 0.07 nφ, 50 holes) equipped with a 5 μm SUS 316 sintered filter was heated to 70°C, and the discharge pressure was 50 kg/a.
The dope was extruded from the nozzle with a pressure of "n".

After passing through five layers of air, the extruded dope is introduced into water at 0°C, and from this coagulation bath, coagulation progresses as it passes through a glass tube in which moving water flows down, at a circumferential speed of 2oom/min. Does it rotate? I rolled it up on a pin.

The obtained yarn was washed with running water overnight and then dried with hot air at 100° C. to obtain a yellow yarn having a single yarn of 1.5 denier.

The physical properties of the obtained yarn are shown in Table 2.

During this spinning, there were no spinning troubles such as spindle clogging or spindle abnormality increase, and very stable spinnability was exhibited.

Comparative Example 3 Using the same polymer as in Comparative Example 2, an optically anisotropic dope was prepared in the same manner as in Example 3, and spinning was performed under the same conditions.

The physical properties of the yarn thus obtained are shown in Table 2. Compared to the yarn of Example 3, the strength and elongation were slightly inferior, and in addition, the moisture absorption rate was high.

Almost no trouble occurred during this spinning, but the increase in spinneret pressure was quite large.

Example 4 In the same polymerization tank as Example 1, 100 N-methylpyrrolidone
Dissolve 70 parts of calcium chloride in 0 parts, then 44.6 parts of PDA (1 mole excess to the TPO added later)
was dissolved. After cooling to -2°C, 3 parts of TPC84 (
Solvent 1! 0.4 part of benzoyl chloride (equivalent to 1 mole relative to TPO) was added in a molten state, and then 0.6 part of benzoyl chloride (equivalent to 1 mole relative to TPO) was added at once in powder form. 2-3
Since the polymer solidified within minutes, the polymerization was carried out in the same manner as in Example 1, and pale yellow PPTA with ηinh of 5.1 was
Obtained 96 copies.

The amount of end groups and apparent density of this polymer are amine end group amount: 25.1 milliequivalents/ume cargonic acid end group amount: 22.7 milliequivalents lt/kg apparent density
x, 3ey/α3.

A film of 23 μm was formed in the same manner as in Example 1 using a polymer of
A yellow transparent film with a thickness of .

The moisture absorption dimensional change rate of this film is 3.7 x 10 m/+m in the longitudinal direction, I
RH width direction 5.5X10 rx□,%R
It was H.

Example 5 In the polymerization tank used in Example 1, N-methylpyrrolidone 1
000 parts, 70 parts of calcium chloride was dissolved therein, and then 44.6 parts of PDA was dissolved therein. After cooling to -2℃8
5.1 parts of TPO was added all at once in a molten state, and then polymerization was carried out under the same conditions as in Example 1. The obtained yellow polymer has an ηlnh of 4.9 and an apparent density of 1.36.
η, amine end group 45.1 milliequivalents/
Yukaru? The amount of acid terminal groups was 31.8 meq/unit.

100 parts of this dried polymer was dispersed in tetrahydrofuran, 0.8 parts of phenyl isocyanate was added,
2 on a 25°C water bath using a magnetic stirrer.
Stir for hours.

As a result of drying the polymer one by one and quantifying the amount of end groups, η
Inh and density remained unchanged, and PPTA was obtained having values of 27.8 milliequivalents of amine end groups/29.81 equivalents of carboxylic acid end groups/yield.

Using this polymer, an optically anisotropic Dogu was prepared in the same manner as in Example 1, and a film was formed to obtain a yellow transparent film with a thickness of 24 μm. The moisture absorption dimensional change rate of this film is in the longitudinal direction 6. lX10 Bow Ax efi arrest H width direction 7.3X10-5shi/ichiRH
Met.

Example 6 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.2 parts (equivalent to 90.4 moles per 1 mol of solvent) were dissolved. After cooling this solution to -2°C, add 85.1 parts of TPO (
(equivalent to 101 molti based on PDA) was added at once in a molten state. After 3 minutes, the polymerization reaction product that had solidified into a cheese-like shape was placed in a two-screw closed kneader, and immediately after that, 100 parts of N-methylpyrrolidone K and 2 parts of Ayu 9F (5 molti based on PDA) were dissolved. The resulting solution was added thereto, and the mixture was pulverized and subjected to shearing force for 30 minutes in the same kneader. The pulverized polymer was transferred to a Henschel mixer and further pulverized by adding approximately the same amount of water, then washed several times with warm water and dried at 110°C.

As a result, ηinh4.1. Apparent density 1.36?
95 parts of PPTA of /c- were obtained. The amount of terminal groups in this polymer was 28.3 mm/unit of amine terminal groups/25.6 mm/unit of eucarmenic acid terminal groups.

Next, an optically anisotropic dope was prepared using the same polymer as in Example 1, and a film was formed to obtain a yellow transparent film with a thickness of 20 μm. The moisture absorption dimensional change rate of the obtained film in the longitudinal direction is 4.8 x 1O = zz7 one inch RH
Width direction: 6.6 x 10''5 x 4% RH.

Example 7 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.6 parts (equivalent to 101 molti based on TPO) were dissolved. After cooling this solution to -2°C, TPC84,3
1 part (equivalent to 0.4 mole per 11 parts of solvent) was added at once in a molten state. After 2.5 minutes, the polymerization reaction product solidified into a cheese shape was transferred to a twin-screw closed kneader in the same manner as in Example 6, and immediately after that, 3 parts of benzoyl chloride (based on TPC) was added to 100 parts of N-methylpyrrolidone. A solution in which 5 molti (corresponding to 5 molti) was dissolved was added, and pulverization and shearing force were applied for 30 minutes. The pulverized polymer was transferred to a Henschel mixer and further pulverized by adding approximately the same amount of water, then washed several times with warm water and dried at 110°C. For this, ηin
At h4.8, 93 parts of PPT with an apparent density of 1.35 were obtained. In addition, the amount of terminal groups of PPTA is: Amount of amine terminal groups: 22.8 milliequivalents/yukal? The amount of identified terminal groups was 26.1 milJ equivalent/unit.

An optically anisotropic dope was prepared in the same manner as in Example 1,
Furthermore, the film obtained by manual film production was yellow transparent and had a thickness of 2
At 1 μm, the moisture absorption dimensional change rate is 4.2 in the longitudinal direction.
X10″″5 Tength V-chi RH width direction 6. I
X 10 mx/ym ChiRH.

Example 8 In the same polymerization tank as in Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.2 parts (equivalent to 0.4 mole per 11 parts of solvent) and 0.4 part of octylamine (equivalent to 1 mole per PDA K) were dissolved. After cooling to -2°C, 816 parts of TPO (PD
(corresponding to 101 molti of A) was added all at once in a molten state. After 3 minutes, the polymer solidified into a cheese-like shape, so the polymerization reaction product was immediately transferred to a twin-screw closed kneader, and pulverized and sheared in the same kneader for 20 minutes. Next, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, and the mixture was further pulverized, filtered, washed several times with hot water, and dried in hot air at 110°C. the result,
ηinh4.3, apparent density 1.361-/lt? 95 parts of pale yellow PPTA were obtained.

The results of measuring the amount of terminal groups were as follows.

Amine end group! 30.4 mm drawing amount / caldic acid end group amount 23.1 mm lj equivalent / Yu In addition, using this polymer, an optically anisotropic dope was prepared by the method of Example 1, and a film was formed. A yellow transparent film with a thickness of 25 μm was obtained.The moisture absorption dimensional change rate of the obtained film was as follows.

Longitudinal direction 6. lX10""5 exposure/m%RH width direction 6.9 X 10""MV'B ChiR
H Example 9 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.2 parts (corresponding to 1 mole of solvent and 0.4 mole of solvent) and 0.4 part of cyclohexyC amine (corresponding to 1 mole of PDA) were dissolved. After cooling to −2° C., 81.6 parts of TPC (equivalent to 101 molti based on PDA) was added at once in a molten state. After 3 minutes, the polymer solidified into a cheese-like shape, so
This polymerization reaction product was immediately transferred to a twin-screw closed kneader,
Grinding and shear force application were performed for 20 minutes in the same Nigu. Next, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, and the mixture was further pulverized, filtered, washed several times with hot water, and dried in hot air at 110°C. Accordingly, ηinh 4.23, apparent density 1.361-
/cry? 94 parts of PPTA were obtained. The amount of terminal groups is as follows: Amino terminal group amount 32.1 milliequivalents/Yucarginic acid terminal group jl 26.7 milliequivalents/Mikono P
Using PTA, an optically anisotropic Dogue was prepared using the same method as in Example 1, and as a result of film formation, longitudinal direction 7
．． 0X10-5-11%RH width direction 7.8
Has a moisture absorption dimensional change rate of X10-5 Shima Ays Chi RH,
A film with a thickness of 23 μm was obtained.

Example 10 In the same polymerization tank as in Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.2 parts (equivalent to 0.4 mol per 11 parts of solvent) and p-
0.5 part of fluoroaniline (equivalent to 1 molty per PDA) was dissolved. After cooling to −2° C., 81.6 parts of TPC (equivalent to 101 molti based on PDA) was added at once in a molten state. After 3 minutes, the polymer solidified into a cheese-like shape, so
This polymerization reaction product was immediately transferred to a twin-screw closed kneader,
Grinding and application of shear force were performed in the same kneader for 20 minutes. Next, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, and the mixture was further pulverized, filtered, washed several times with hot water, and dried in hot air at 110°C. As a result, PP with ηinh4.7 and apparent density 1.36η
95 parts of TA were obtained. The results of measuring the amount of terminal groups were as follows: amine end group amount: 23.1 mm/lCg/carboxylic acid end group amount: 18.3 mm/lICg.

An optically anisotropic Dogue was prepared using the same polymer as in Example 1, and as a result of manual film formation, a yellow transparent film with a thickness of 25 μm was obtained.

The moisture absorption dimensional change rate of this film was as follows.

Longitudinal direction 3.3X10 μm%RH Width direction 4.3X10-5-CH RH Example 11 In the same polymerization tank as Example 1, N-methylpyrrolidone 100
Dissolve 70 parts of calcium chloride in 0 parts of PDA4
4.6 parts (1 molar excess over TPO added later) was dissolved. After cooling to -2°C, 84.3 parts of TPC (equivalent to 0.4 mole relative to solvent 1) was added in a molten state, followed by 0.6 part of p-fluorobenzoyl chloride (
1 mole phase per TPO was added at once in powder form. The polymer solidified in 2 to 3 minutes, so polymerization was carried out in the same manner as in Example 1, and PP7 of ηinh4-5 was
I got 95 copies.

The amount of end groups and apparent density of the polymer are amine end group amount 24.0 milliequivalent 1 kg carboxylic acid end group jl 24.2 milliequivalent ft/'9 apparent density
1.351I-A7! It was L'.

Using this polymer, a film was formed in the same manner as in Example 1, and 23μ
A yellow transparent film with a thickness of m was obtained.

The moisture absorption dimensional change rate of this film is: 5.7 x 10-5mx/itog in the longitudinal direction
HH width direction 6.6X10 Wing quarters/ChiR
It was H.

Example 12 Using the same polymer as in Example 10, spinning was performed by the method of Example 3 to obtain a yellow filament with a single yarn denier of 1.5. During spinning, there were no problems such as spindle clogging or abnormal increase in spindle normality, and the spinning performance was very stable.

Table 3 shows the physical properties of this yarn and the yarn that was further heat-treated at 300° C. for 150 seconds.

Example 13 In the same polymerization tank as in Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of PDA
44.2 parts (equivalent to 0.4 mole of solvent 1) and 2,
4. 0.6 part of rottrifluoroaniline (corresponding to 1 molty of PDA) was melted. After cooling to −2°C, TP
81.6 parts of O (101% relative to PDA was added at once in a semi-molten state).

After 3 minutes, the polymer solidified into a cheese-like shape, so the polymerization reaction product was immediately transferred to a two-screw closed kneader, and pulverized and sheared in the same kneader for 20 minutes. Next, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, and the mixture was further pulverized, filtered, washed several times with hot water, and dried in hot air at 110°C. As a result, ηi
nh4-1, P with apparent density 1.351P/crtt"
95 parts of PTA were obtained. The results of measuring the amount of terminal groups were 32.51 equivalents of amine terminal groups/24.61 equivalents of cargonic acid terminal groups.

An optically anisotropic Dogue was prepared using the same polymer as in Example 1, and a transparent yellow film with a thickness of 23 μm was obtained. The moisture absorption dimensional change rate of this film was as follows.

Longitudinal direction 3.2X10-5 V-chi R) I Width direction 4. OX 10-5tax/+m%
RI (hereinafter referred to as Table 2, Table 3 [Effects of the Invention]) A feature of the present invention is that it has reactivity with amines or carboxylic acid chloride. However, by using the PPTA of the present invention, the hygroscopicity is reduced and the dimensional change rate due to moisture absorption (! or water absorption) is reduced. This is thought to be due to the fact that by capping with the substituent, the amorphous part of the molded product resulting from the end of the molecular chain becomes hydrophobic.
In a PPTA polymer with a PPTA polymer of 3 or more, the amount of end groups is approximately 1 or less with respect to the total amide bond, and until now, there has been no phenomenon in which the hygroscopicity is significantly reduced just by making a part of the amide bond hydrophobic. Although many researchers have wanted to continue their research on PPTA, they have not been able to achieve it.

Furthermore, as is clear from the examples, the molded products obtained by the method of the present invention not only exhibit excellent moisture absorption dimensional stability, but also exhibit stable high mechanical properties as the moisture absorption rate decreases. As can be seen from the fact that the increase in spinneret pressure is small, the moldability is improved, and the inherent heat resistance, chemical resistance, and electrical insulation properties of PPTA are also improved.

Due to these major improvements, the PPTA molded products obtained by the method of the present invention can be used in fields that require high dimensional accuracy, heat resistance, and mechanical properties, such as films for flexible printed wiring boards, base films for magnetic tapes, Alternatively, it can be preferably used for applications such as fibers for reinforcing optical fiber cables.

In addition, when plastics reinforced with PPTA* fibers are used, for example, in aircraft parts, the temperature and humidity of the environment in which they are used fluctuates significantly and this is repeated, so the PPTA fibers gradually absorb moisture. It has been reported that as a result, dimensional changes occur and eventually cracks appear in plastics, but even for such uses, the fibers obtained by the method of the present invention are free from the above-mentioned defects. It is very useful as

Claims (1)

[Claims] 1. When producing a molded article from an optically anisotropic dope consisting of polyparaphenylene terephthalamide and concentrated sulfuric acid, ηinh is 3.0 or more and the apparent density is 1.38 g.
/cm^3 or less, and the amine end group is 80-10×(
ηinh) milliequivalent/kg or less, and a polyparaphenylene terephthalamide molded product characterized by using polyparaphenylene terephthalamide having a carboxylic acid terminal group of 80-10×(ηinh) milliequivalent/kg or less manufacturing method.