JPS6346222A - Poly-p-phenylene terephthalamide - Google Patents

Abstract

PURPOSE:To obtain the titled polymer giving a molded article having excellent dimensional stability to moisture, mechanical properties, electrical properties and moldability and low hygroscopicity, by decreasing the amount of terminal amine group and terminal carboxylic acid group in the polymer. CONSTITUTION:The objective polymer has a logarithmic viscosity etainh of >=3, an apparent density of <=1.38g/cm<3> and amounts of terminal amine group and terminal carboxylic acid group of <=80-10X(etainh)m-equivalent/kg each. The polymer can be produced e.g. by using terephthaloyl dichloride (TPC) and p- phenylenediamine as starting raw materials in excess of TPC, carrying out low-temperature solution polymerization adding an aniline, etc., as a terminal blocking agent keeping the overall ratio of amino group to carboxylic acid chloride group to 1:1 and blocking the terminal carboxylic acid group of the resultant polymer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improved polyparaphenylene terephthalamide (hereinafter abbreviated as PPTA),
More specifically, PP in which the amount of amine end groups and the amount of carboxylic acid end groups in the polymer is reduced in order to reduce the moisture absorption of the molded product obtained by molding the optically anisotropic dope.
This is related to TA.

[Conventional technology]

PPTA, which is obtained by polymerizing terephthalic acid dichloride (hereinafter abbreviated as TPO) and paraphenylenediamine (hereinafter abbreviated as PDA), has a rigid 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 recently attracted particular attention as industrial materials such as tire cords and reinforcing materials for FRP due to their excellent mechanical properties and heat resistance. . In addition, 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 manufacturing PPTA film have been disclosed (for example, No. 5747886 Koyuki Old.

It is known that PPTA can be produced by low-temperature solution polymerization in an amide-based scratchy solvent (for example, JP-A-54-100496). Because it has an amide bond produced by dehydrochloric acid condensation of the monomer and a hydrophilic group such as an amine terminal group and a carboxylic acid terminal group as the molecular chain terminal group at the end of polymerization, molded products made using such ordinary PPTA are It easily absorbs moisture, and therefore has disadvantages such as changes in dimensions, decreases in strength and elastic modulus, and fluctuations in electrical characteristics due to moisture absorption.

[Problems to be Solved by the Invention] The purpose of the present invention is to improve the moldability and the mechanical and
PP has good thermal properties, does not exhibit the moisture absorption defects mentioned above, and has excellent dimensional stability and excellent mechanical and electrical properties even under harsh conditions of high temperature and high humidity.
The object of the present invention is to provide a PPTA polymer suitable for obtaining TA molded articles.

[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. As we continued to study the relationship between the rate of dimensional change due to moisture absorption, that is, the rate of dimensional change due to moisture absorption, of molded products obtained by As the amount of both amine and carboxylic acid terminal groups decreases, we discovered the surprising phenomenon that the moisture absorption dimensional change rate of Li molded products using this decreases.As a result of further intensive research, we completed the present invention. It has arrived.

Specifically, the present invention has an ηinh of 3.0 or more, an apparent density of 1.38g/cd or less, an amine end group of 80-10X (ηinh) milliliter/1g or less, and a carbon The acid end group is 80-10X (
The present invention provides PPTA characterized in that it is less than or equal to ηinh) per milliliter/1g.

The polymer of the present invention is PPTA having the repeating unit +CO+CO-NH+NI+)- as shown below, and must satisfy the following requirements, that is, the PPTA of the present invention
The degree of polymerization is usually 3.0 because if it is too low, molded products with the excellent mechanical properties inherent to PPTA cannot be obtained.
As mentioned above, a polymer having a degree of polymerization that provides an logarithmic viscosity (ηinh) of 3.5 or more is preferably selected.

The polymer of the present invention is less than 1.38 g/-, preferably 1
．． It has a density of 36 g/cal or less. Polymers with high density generally have high crystallinity, and such polymers have poor solubility in concentrated sulfuric acid during dope preparation, resulting in uneven dope, undissolved polymer remaining, and difficulty in dissolving. As the time required 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 not preferable.

Furthermore, the polymer of the present invention must satisfy the following conditions regarding its terminal groups. That is, the amount of amine end groups is 80-10x (ηinh) milliequivalent/1
g or less (preferably 7O-10
-1Qx (771nh) milliequivalent/kg or less (preferably 70-10×(ηinh) milliequivalent/1g or less)
The hygroscopicity of a PPTA molded product is closely related to the amount of end groups, and if a polymer with an amount of end groups outside of this range is used, the hygroscopicity of the resulting molded product cannot be sufficiently improved. This is because mechanical properties tend to deteriorate and electrical properties such as electrical insulation properties tend to fluctuate.

[Action of the invention]

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 can polymer molded products be made of P?
Even though it is PTA, it cannot be completely crystalline and has a certain amount of amorphous portion, and it is thought that most of the molecular chain ends are present in this amorphous portion. 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, it is also effective and a preferred embodiment to heat-treat the molded product obtained using the polymer of the present invention within a range that does not cause the polymer to absorb moisture.

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
Several researchers have studied and clarified the relationship between the viscosity and number average molecular weight of concentrated sulfuric acid solutions of PTA (
For example, M. Arpin Dimacromoleculare Hemi-1 Vol. n, p. 581 (1976)). According to that knowledge, when TPO and PDA are stoichiometrically polymerized, when ηinh is 5, the number average molecular weight is approximately 20.
000 and there are 2 end groups in 20000 g of polymer.

In other words, there are approximately 100 milliequivalents of end groups in 1 kg of polymer, 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, which is approximately 4% per kg of polymer.
There will be 0 milliequivalents each of amine and carboxylic acid end groups. Comparing these numbers, it is clear that the polymers of the present invention have very low amounts of both amine and carboxylic acid end groups.

Until now, T.
Although the composition of PC and PDA has been studied, the main focus of these studies has been on increasing the molecular weight of the resulting polymer, and only by changing the charging ratio of TPC and PDA. There are very few examples that focus on the basics. Although a spinning method using a polymer with an excessively large number of amine end groups by manipulating the molar distribution of TPO and PDA during polymerization has been disclosed (US Pat. No. 39,339).
No. 63), which is also only intended to improve spinnability,
As in the present invention, there is no precedent for a technology that attempts to improve even the physical properties of a molded product by actively manipulating the molecular chain terminal groups, and these known technologies cannot can't get it.

Next, an example of a method for producing the polymer of the present invention will be shown. Such PP with few amine end groups and few carboxylic acid end groups
Using TA, PDA and TPC using a so-called low-temperature solution polymerization method.
When preparing by reaction, one or more substances other than TPC and PDA that are reactive with amines or carboxylic acid chlorides are added to react with the terminal amine or terminal carboxylic acid chloride to block the molecular chain ends. It can be manufactured by

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, 0-1m
- or p-) luidine, 0-lm- or p-nitroaniline, α- or β-naphthylamine, 2-
13- or 4-biphenylamine, ethylamine,
Mono-class amines such as propylamine, isopropylamine, cyclohexylamine, secondary monoamines such as N-methylaniline, diethylamine, piperidine, or benzoyl chloride, 0-lm- or p-)
Monocarboxylic acid chlorides such as luoyl chloride, propionyl chloride, and cyclohexane carbonyl chloride, or phenyl isocyanate, ethyl isocyanate, phenyl inthiocyanate, and ethyl isothiocyanate are used. In addition, in order to make the effect of such terminal blocking even more remarkable, it is also a useful embodiment to use, for example, a compound in which one or more of the hydrogen atoms in the above compound is substituted with fluorine. .

Furthermore, the method of adding and reacting these substances is not particularly limited. For example, in a known polymerization method (for example, Japanese Patent Application Laid-Open No. 100496/1983), they may be added and reacted at any time during polymerization. Alternatively, the polymer once polymerized may be impregnated with them in a suitable solvent and reacted.

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

Polymerization is most conveniently carried out by a so-called low-temperature solution polymerization method in which TPO and PDA are stirred and mixed in an amide solvent.Solvents for polymerization include N-methylpyrrolidone, N-methylpyrrolidone,
N,N-dimethylacetamide, N-acetylpyrrolidine, tetramethylurea, hexamethylphosphoramide, etc., or mixtures thereof in arbitrary proportions, or mixtures of these with lithium chloride, calcium chloride, etc. are used. The monomer concentration during polymerization is approximately 0.1 to 1.0 mol/
It is. In the conventional PPTA polymerization method, TPC and PDA are charged in a ratio of approximately 1:1 and mixed with stirring in the solvent, but special measures are required to obtain the polymer of the present invention. For example, the molar balance of TPC and PDA is such that TPC is in excess.When PDA is 100, TPC is 100. About Q~101 is preferable; this means that if the molar balance is disturbed too much,
This is because the molecular weight cannot be made sufficiently high. )
At the time of preparing the 7mer, one or more of the monoamines described above are added so 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. Naturally, TPC and PD
It is also possible to reverse the molar balance of A to the above and use a monocarboxylic acid chloride compound or the like as the terminal capping agent.

The amount of end-capping agent to be added is determined by adjusting the amount of TPC (or P
D A) 0.1 to 1.0 is appropriate for 100. In addition, in the polymer obtained by polymerization, the ratio of terminal groups to Kaneko Tsumar is when ηinh is 3.0,
Approximately 0.7%, approximately 0.5 when ηinh is 5.0
%, and 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 a certain extent. When the polymerization progresses, the PP produced
Since TA may precipitate from the solvent, the reaction with the sealant in this case is a heterogeneous reaction. Therefore, when adding a sealant during polymerization, the sealant and amino groups (
In order to increase the probability of reaction with the carboxylic acid chloride group (or carboxylic acid chloride group) and perform effective sealing, it is preferable to use an excessive amount of the sealant. Preferably, the amount of 5- to
10 times better. However, if the amount is too excessive, the progress of the subsequent polymerization will be inhibited, which is not preferable.

The polymerization temperature is selected to be 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, for example, into a Henschel mixer and ground by adding approximately the same amount of water.
After further washing with water several times, it is filtered or centrifuged and dried to finally obtain 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 a monoisocyanate, a monocarboxylic acid chloride, a monoaliphatic amine, etc. in a solid phase to perform end-blocking. is also possible.

The logarithmic viscosity (ηinh) of the PPTA thus obtained is defined as follows.

0,5 where ηrel is the polymer solution (96% by weight sulfuric acid 100%
m7! 0.5 g PPTA) and pure solvent at 25°C.
This is the ratio of outflow times measured with a capillary viscometer at .

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

Amine end group determination method: Weigh 0.2 g of the dried polymer into a 400 ml flat bottom flask and add 25 mff of ion-exchanged water.

Add to this 0.2g of sodium hydrogen carbonate and 25m of ethanol.
1 and further 1.25 g of 1-fluoro-2゜4-
Add dinitrobenzene. A Dimroth condenser was attached to this flask, and the contents of the flask were stirred with a magnetic stirrer and refluxed for 4 hours in a water bath maintained at 80°C. The reddish-brown colored polymer is filtered and washed thoroughly with acetone. The polymer is then dried under reduced pressure at 80° C. for 4 hours. The polymer thus obtained is 0.025
g into a 5.0 ml beaker, add 25 ml of methanesulfonic acid, and stir with a magnetic stirrer at room temperature until completely dissolved. At this time, the mouth of the beaker should be sealed with a suitable sealant, and the light should be shielded as much as possible during the dissolution. This is because the dinitrobenzene group is highly photoreactive 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 Absorption Photometer Model 6B manufactured by Te Rika Kenkyusho) using a quartz cell with an optical path length of 1. At this time, the amount of amine end groups per polymer is determined. However, T is 25 g of untreated PPTA O when the transmittance of methanesulfonic acid is 100%.
m1 is the transmittance of the solution dissolved in ml, T+ is the transmittance of the methanesulfonic acid solution of PPTA subjected to the above treatment, when the transmittance of methanesulfonic acid is taken as 100%, and ε is the transmittance of the methanesulfonic acid solution of PPTA subjected to the above treatment. The molar extinction coefficient of dinitrobenzene group measured using the compound, the value is 7100 (1/
mol-cs).

Method for quantifying carboxylic acid end groups To quantify carboxylic acid end groups, first wash the polymer thoroughly with water to make sure that no free acid or alkali remains in the polymer. To confirm this, disperse the polymer in an appropriate amount of water, heat and stir at around 50°C, filter the polymer, and then titrate the filtrate with an alkali or acid such as caustic soda or hydrochloric acid. The 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,
10-3 normal sodium hydroxide solution (water-ethanol 1:1 solution) 25mj! Add. 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 cooler.

The polymer is separated by filtration, washed with a small amount of ethanol, this washing liquid is combined with the previous filtrate, and this is titrated with a 10-3 N aqueous hydrochloric acid solution. The amount of 10-3 normal hydrochloric acid aqueous solution required for neutralization at this time is defined as V, ml. In the same procedure, 10
- Reflux only the 3N sodium hydroxide solution, then titrate with a 10N hydrochloric acid aqueous solution, and calculate the amount of the hydrochloric acid aqueous solution required for neutralization. ml, the desired amount of carboxylic acid end groups is per 1 kg of polymer.The amount of carboxylic acid end groups is determined by performing the entire process in an inert gas atmosphere to avoid absorption of carbon dioxide gas from the atmosphere. Let's do it.

When actually molding the polymer of the present invention, a known method for molding PPTA, that is, a method for molding an optically anisotropic dope made of PPTA and concentrated sulfuric acid or the like can be used.

As the solvent used to prepare the dope, in addition to sulfuric acid, chlorosulfuric acid, fluorosulfuric acid, or a mixture of these and sulfuric acid can be used, but from the viewpoint of solubility, concentrated sulfuric acid of 96% by weight or more is preferable, and the polymer concentration is at room temperature. or a concentration that exhibits optical anisotropy at higher temperatures. Specifically, it is about 10% by weight or more, preferably 15% by weight 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. Dopes with such polymer concentrations often need to be slightly warmed to allow them to flow and be molded, but as the temperature increases, the rate of deterioration increases, so dopes with temperatures ranging from room temperature to 100°C are usually used. be done.

The dope 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. Regarding the production of PPTA film, for example, Japanese Patent Publication No. 57-1788
The method disclosed in Japanese Patent No. 6 can be used, but the method is not limited thereto.

〔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.

Example 1 70 parts of calcium chloride was dissolved in 1000 parts of N-methylpyrrolidone in a polymerization tank having a stirring blade rotating at high speed, an inlet and an inlet for dry nitrogen, and an inlet for raw materials, and then 44.5 parts of PDA was dissolved.
22 parts (equivalent to 0.4 mol per IJ of solvent) and 0.4 part of aniline (equivalent to 1 mol % relative to PDA) were dissolved. −
After cooling to 2°C, add 1 part of TPC85 (1 part to PDA).
(equivalent to 0.01 mol%) was added all 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 two-screw closed kneader, and ground in the same Nigu.
After applying shearing force for 20 minutes, the pulverized polymer was transferred to a Henschel mixer, an approximately equal amount of water was added thereto, further pulverized, filtered, washed several times with warm water, and heated to 110°C.
dried in hot air. As a result, 95 parts of pale yellow PPTA with an ηinh of 4.3 and an apparent density of 1.35 g/cd was obtained.

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

Amount of amine end groups: 31.3 meq/kg, carboxylic acid end groups: 125.9 meq/kg Next, using this polymer, film formation was performed in the following manner.

99.6% sulfuric acid 88% in a 500me separable flask
1 part, and 12 parts of the above polymer was divided into two parts.
The dope was added while stirring for a total of 40 minutes (at room temperature), and stirring was continued for another 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 preheated to 120° C., and a film was formed manually using an applicator with a 0.1 mm slit. Immediately, this was placed in hot air kept at 120°C, left to stand for 10 minutes, and subjected to constant force ratio processing based on optical anisotropy. Thereafter, the film was immersed together with the glass plate in pure water to be deoxidized, and the film was peeled off. This wet film was sandwiched between metal frames and dried in hot air at 250° C. for an 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 in an atmosphere of 85% relative humidity using TMA (Thermomechanical Measuring Instrument, Shimadzu Corporation Standard ^-30), and calculated using the following formula.

Moisture absorption dimensional change rate (m/drunk, %RH) Elongation of sample (ms) Original length of sample (m) x 85 (%RH) The size of the sample at the time of measurement was 2 mm in width and 8 u in effective grip distance. there were.

As a result, the moisture absorption dimensional change rate of the above film was as follows: Long plane direction 3.9X10-'Tsuru/1m・%RH Width direction 6
．． It was 5×10-'Tsuru/1kl・%RH.

Example 2 The same polymer 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 1.5m curved pipe from the dope tank to the die via the gear pump is maintained at 65℃, and Q, l wX3
It was cast from a goo with a slit of 0.00 wm onto a mirror-polished tantalum belt at a take-up speed of 2 m/min.
After exposure for 0 seconds and the dope became transparent, it was coagulated in water at 10°C. This coagulated film was washed with water at room temperature overnight and then dried with hot air at 250°C for 1 hour to a thickness of 20°C.
A yellow transparent film of μm size was obtained. 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 (
(equivalent to 0.4 mol per liter of solvent) was dissolved.

After cooling to -2°C, 85.1 part of TPO (equivalent to 0.4 mol per 12 solvent) was added to -1, followed by Example 1.
Polymerization was carried out under the same conditions as in the method shown in , and Winh was 4.
6. A pale yellow PPTA with an apparent density of 1.35 g/cd was obtained.

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

Amine terminal group amount: 47.3 milliequivalents/kg Carboxylic acid terminal group amount: 35.9 milliequivalents/kg Using this polymer, a film was prepared in the same manner as in Example 1, and the dimensional change rate upon moisture absorption was measured. As shown below, the dimensional stability was inferior to that of Example 1.

Long horizontal direction 9. OX 10-Stm/ Dragon・%RH Width direction 10.8
78, pale yellow PPTA with apparent density 1.37 g/cd
I got it. The amount of end groups of this polymer was 140.5 meq. of amine end group/32.1 meq. of k+r carboxylic acid end group/kg, respectively.

This polymer was added at a ratio of 12 parts to 100 parts of 99.4% by weight sulfuric acid to obtain an optically anisotropic dope 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% sulfuric acid at 80% by volume.
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 mΦ - 50 holes) equipped with a 5 μm SOS 316 sintered filter was heated to 70°C, and the discharge pressure was 50 kg/cd.
I pushed the dope out of the nozzle.

After the extruded dope passes through 511 air layers, it is heated to 0°C.
From this coagulation bath, coagulation proceeded while passing through a glass tube in which moving water was flowing, and was wound up onto a bobbin rotating at a circumferential speed of 200 m/min.

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 clogging of the spindle or abnormal increase in spindle normality, and very stable spinning performance 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 yarn was slightly inferior in strength and elongation and had a high moisture absorption rate.

Almost no trouble occurred during this spinning, but the spinneret pressure increased considerably.

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 mol% excess with respect to TPO added later)
was dissolved. TPC after cooling to -2℃: 84.3
(equivalent to 0.4 mol based on solvent 11) was added in the melt, followed by 0.6 part of benzoyl chloride (TP
(equivalent to 1 mol % based on C) 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 to obtain pale yellow P with ηinh5.1.
Received 96 copies to PT.

The amount of end groups and apparent density of this polymer are as follows: amine end group it 25.1 meq/kg carboxylic acid end group ff 122.7 meqffi/kg apparent density
It was 1.36g/aj.

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

The moisture absorption dimensional change rate of this film was: 3.7 x 10-'mm/+n.%RH in the longitudinal direction and 5.5 x IQ-'m/m.%RH in the width direction.

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° C., 85.1 parts of TPO in a molten state was added all at once, and then polymerization was carried out under the same conditions as in Example 1. The obtained yellow polymer had an ηinh of 4.9 and an apparent density of 1.
36 g/-, amine end groups 45.1 meq/kg carboxylic acid end groups 31.8 meq/kg
It was kg.

100 parts of this dried polymer was dispersed in tetrahydrofura, 0.8 part of phenyl isocyanate was added, and 2
The mixture was stirred for 2 hours using a magnetic stirrer on a 5°C water bath.

As a result of filtering and drying the polymer and quantifying the amount of terminal groups, ηi
PPTA was obtained with values of: amine end group 27.8 meq/kg carboxylic acid end group 29.8 meq/kg with no change in nh and density.

Using this polymer, an optically anisotropic dope 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: Longitudinal direction: 6.1 x 10-'mm/m ・%RH Width direction: 7.3
Met.

Example 6 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of P D
44.2 parts of A (equivalent to 0.4 mol per 11 solvent) was dissolved. After cooling this solution to -2°C, T P C8
5.1 parts (corresponding to 101 mol % 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 transferred to a twin-screw closed type Nigu, and immediately after that, a solution of 2 parts of aniline (5 mol % based on PDA) dissolved in 100 parts of N-methylpyrrolidone was added. The mixture was then crushed and subjected to shearing force for 30 minutes in the same Ni-Goo. The pulverized polymer was transferred to a Henschel mixer, and an equal amount of water was added thereto for further pulverization. After washing several times with warm water,
This gave 95 parts of PPTA with an ηinh of 4.1 and an apparent density of 1.36 g/cj. The amount of terminal groups in this polymer is 28.3 mm equivalent to the amount of amine terminal groups! / kg carboxylic acid terminal group 3jl 25.6 mm/kg
Met.

Next, using this polymer, an optically anisotropic dope 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 20 μm. The moisture absorption dimensional change rate of the obtained film in the longitudinal direction was 4.8 x 10-”tm/m %R
H width direction was 6.6X10-'Tsuru/fl・%RH.

Example 7 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of P D
A44.6 parts (equivalent to 101 mol% based on TPO)
was dissolved. After cooling this solution to -2°C, T P
3 parts of C84 (corresponding to 0.4 mol % based on 11 solvents) was added in a molten state all at once. After 2.5 minutes, the polymerization reaction product solidified into a cheese-like shape was transferred to a two-screw closed Nigu in the same manner as in Example 6, and immediately after that, 3 parts of benzoyl chloride (based on TPO) was added to 100 parts of N-methylpyrrolidone. 5 mol%
) was added thereto, and pulverization and shearing force were applied for 30 minutes. Transfer the pulverized polymer into a Henschel mixer, add approximately the same amount of water, and further pulverize.
Then, it was washed several times with warm water and then dried at 110°C. As a result, P with ηinh4.8 and apparent density 1.35g/aJ
93 parts of PTA were obtained. Further, the amount of terminal groups of this PPTA was as follows: amine terminal group amount: 22.8 milliequivalents/kg; carboxylic acid terminal group amount: 26.1 milliequivalents/kg.

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, 21 μm thick, and had a dimensional change rate of 4.2×10 in the longitudinal direction after moisture absorption.
-%van/Fin/%RH width direction 5.1 X I
Q-'m/tm-%RH.

Example 8 In the same polymerization tank as in Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of P D
44.2 parts of A (equivalent to 0.4 mol per 11 solvent) and 0.4 part of octylamine (equivalent to 1 mol% relative to PDA)
was dissolved. After cooling to -2°C, 81.6 parts of TPO (
(equivalent to 101 mol % based on PDA) was added 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, transfer the crushed polymer into a Henschel mixer,
After adding approximately the same amount of water and further pulverizing, the mixture was filtered, washed several times with warm 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 1.36 g/cd was obtained.

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

Amine end group amount: 30.4 meqffi/kg Carboxylic acid end group it: 23.1 meq/kg Furthermore, using this polymer, an optically anisotropic dope was prepared by the method of Example 1, and film formation was performed. As a result, 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. I X 10-'vm/w %
RH width direction 6.9 x 10-'m/w-%R
H Example 9 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of P D
44.2 parts of A (equivalent to 0.4 mol per 11 solvent) and 0.4 part of cyclohexylamine (1 mol % relative to PDA)
equivalent) was dissolved. After cooling to -2°C, TPC8
1.6 parts (equivalent to 101 mol % 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 type kneader, and pulverized and subjected to shearing force for 20 minutes in the same kneader. The material was transferred to a Henschel mixer and further ground by adding an equal amount of water, filtered, washed several times with hot water, and dried in hot air at 110°C.

As a result, ηinh 4.23, apparent density 1.36
94 parts of PPTA of g/aj were obtained. The amount of terminal groups is 32.1 milliequivalents/kg of amino terminal groups, 26.7 milliequivalents/kg of carboxylic acid terminal groups, respectively.
Using TA, an optically anisotropic dope was prepared using the same method as in Example 1, and as a result of forming a film, the longitudinal direction ? ,OX
10-'w/sx%・RH width direction? , 8X10-
'Tsuru/Has a moisture absorption dimensional change rate of 1% RH, thickness 2
A 3 μm film 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 P D
44.2 parts of A (equivalent to 0.4 mol per 11 solvent) and 0.5 part of p-fluoroaniline (1 mol% relative to PDA)
equivalent) was dissolved. After cooling to -2°C, TPC8
1.6 parts (equivalent to 101 mol % 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 closed twin-screw Niegoo, and pulverization and shearing force were applied in the same Niegoo 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, ηinh4.7, apparent density 1.36g/c
95 parts of PPTA of at was obtained. As a result of measuring the amount of terminal groups, the amount of amino terminal groups was 23.1 milliequivalents/kg, and the amount of carboxylic acid terminal groups was 18.3 milliequivalents/kg.

Using this polymer, an optically anisotropic dope was prepared in the same manner 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 3.3 X 10-sxx/*m ・%R
H Width Direction 4.3X10-'Tsuru/11%RHExample 11 In the same polymerization tank as Example 1, N-methylpyrrolidone 10
Dissolve 70 parts of calcium chloride in 00 parts of P D
44.6 parts of A (1 mol % excess with respect to TPC to be added later) was dissolved. After cooling to -2℃ TPC84,
3 parts (equivalent to 0.4 mol relative to solvent 11) were added in a molten state, and subsequently 0.6 parts of p-fluorobenzoyl chloride (equivalent to 1 mol % relative to TPC) was added at once in powder form. . Since the polymer solidified in 2 to 3 minutes, the polymerization was carried out in the same manner as in Example 1, and ηinh4.
95 parts of PPTA of No. 5 were obtained.

The amount of end groups and apparent density of this polymer are: amount of amine end groups: 24.0 milliequivalents/kg carboxylic acid end groups f
fi 24.2 milliequivalent/kg apparent density
It was 1.35g/cj.

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 I Q-'m/1.%RH in the longitudinal direction
The width direction was 6.6 x 10-'m/fl/%RH.

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 P D
44.2 parts of A (equivalent to 0.4 mol per 12 solvent) and 0.6 part of 2,4.6-)lifluoroaniline (equivalent to 1 mol % relative to PDA) were dissolved. After cooling to -2℃,
81.6 parts of TPC (equivalent to 101 mol % 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 closed twin-screw Niegoo, and pulverization and shearing force were applied in the same Niegoo 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 PPTA with an ηinh of 4.1 and an apparent density of 1.35 g/cd was obtained. The results of measuring the amount of terminal groups were 32.5 milliequivalents/kg of amino terminal groups and 24.6 milliequivalents/kg of carboxylic acid terminal groups.Using this polymer, the optical difference was determined in the same manner as in Example 1. As a result of preparing an orthotropic dope and forming a film, 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 3.2 x 10-'1111/t
m ・%RH width direction 4. OX 10-Smu/
%RH Table 1 Table 2 Table 3 [Effects of the Invention] A feature of the PPTA of the present invention is that the PPTA of the present invention has a hydrophobic substituent that is reactive with amines or carboxylic acid chlorides. The ends are sealed, and by using the PPTA of the present invention, the hygroscopicity of the resulting molded product is reduced, and the dimensional change rate due to moisture absorption (or water absorption) is reduced. This is because the end of the molecular chain is a hydrophobic Z? It originates from the end of the molecular chain by blocking with the A group.

This is thought to be due to the fact that the amorphous parts of the molded product are made hydrophobic. In a PPTA polymer with ηinh of 3 or more, the amount of terminal groups is approximately 1 for the total amide bond.
% or less, and the phenomenon in which the hygroscopicity significantly decreases just by making a part of it hydrophobic has been studied by many researchers until now.
Despite having conducted research on PTA,
It was something that could not be achieved.

Furthermore, as is clear from the examples, the PPTA of the present invention
The molded product obtained by this method not only shows excellent moisture absorption dimensional stability, but also can stably achieve high mechanical properties as the moisture absorption rate decreases, as evidenced by the small increase in spinneret pressure. Furthermore, the inherent heat resistance, chemical resistance, and electrical insulation properties of PPTA are also improved.

Due to these major improvements, molded products obtained using the PPTA 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, resulting in It has been reported that plastics may eventually crack due to dimensional changes, but even for such uses, the fibers obtained from the polymer of the present invention are very suitable as fibers without the above-mentioned defects. Useful.

Claims (1)

[Claims] 1, ηinh is 3.0 or more, and the apparent density is 1.3
8g/cm^3 or less, and the amine end group is 80-10
× (ηinh) milliequivalents/kg or less, and the carboxylic acid terminal group is 80-10 × (ηinh) milliequivalents/k
Polyparaphenylene terephthalamide, characterized in that it has a molecular weight of not more than g.