JPS6055538B2 - Manufacturing method for highly polymerized aromatic polyamide - Google Patents

Description

[Detailed description of the invention] In the field of industrial use
Regarding the white manufacturing method.

More specifically, the present invention relates to a method for economically producing aromatic polyamides having a high degree of polymerization, particularly poly-p-phenylene terephthalamide-based aromatic polyamides, safely from the viewpoint of occupational health. BACKGROUND OF THE INVENTION So-called wholly aromatic polyamides have excellent thermal and mechanical properties and are therefore useful as resins for producing fibers, films, fifrits, and other molded products.

Such wholly aromatic polyamides are produced mainly from aromatic diamines and aromatic dicarboxylic acid dihalides by low-temperature solution polymerization, interfacial polymerization, oligomer polymerization, etc. -27895
No. 42-175 (see Publication No. 42-175). However, many organic It is difficult to produce polymers with a high degree of polymerization using interfacial polymerization or oligomer polymerization.Furthermore, even if low-temperature solution polymerization is used, dimethyl Among the so-called organic polar solvents such as acetamide, N-methylpyrrolidone, N-methylcaprolactam, and tetramethylurea, only hexamethylphosphoramide and mixed solvent systems of this and other organic polar solvents have a high degree of polymerization. On the other hand, as a general method for improving the dissolving power of organic polar solvents for wholly aromatic polyamides, it is known that the solvent is treated with metal halides of group 1 and/or group Ⅰ of the periodic table. A method of adding salt, etc. is known (Tokuko Sho 3).
5-16027).

In addition, polyp in this inorganic salt-added organic polar solvent system
- Polymerization of phenylene terephthalamide has already been investigated, but a polymer with a high degree of polymerization has not been obtained (L.
B. SOkOIOv et al., ■YsOkOmOl, . SOy
ed. ．． Al2,2l85-2198,197). On the other hand, poly p-phenylene terephthalamide (PPI'
A) The degree of polymerization sufficient to obtain high-performance molded products from the wholly aromatic polyamide of system A) cannot be unconditionally defined, but in particular for preparing molded products such as fibers, the logarithmic viscosity (ηInh ) is required to be at least 4.0 (Japanese Unexamined Patent Publication No. 47-4311 Wani Publication), and 5.0 or more is considered preferable2.

However, it has recently been revealed that hexamethylphosphoramide poses an occupational health problem and requires special precautions when using it (Chemica
landEngineeringNews,Sept2
9, l97shi, ltop). OBJECTS OF THE INVENTION The main object of the present invention is to produce a highly polymerized, rose-oriented aromatic polyamide, particularly a poly p-phenylene terephthalamide (PPTA)-based aromatic polyamide, in an industrially hygienic and economically advantageous manner. It is about manufacturing.

Structure of the Invention The above-mentioned object is to polymerize p-phenylenediamine and terephthalic acid chloride or 4,4''-biphenylcarboxylic acid dichloride in an organic polar solvent system, thereby producing an aromatic polyamide, particularly poly p- When producing a phenylene terephthalamide (PPT'A)-based aromatic polyamide, (a) in a solvent system containing N-methylpyrrolidone and calcium chloride in an amount of 1.5% by weight or more and less than the original weight% of the solvent, or (b) a solvent containing at least one selected from dimethylacetamide, N-methylcaprolactam, and urea as a main component and 1.5 to 8 for the solvent;
．． In a solvent system containing 10% calcium chloride (Cal2), the concentration of the polymer forming each reaction component in the polymerization system was 4%.
~ l river %, polymerization reaction is carried out, and
After starting polymerization, use a kneader to form slurry, paste,
The high degree of polymerization aroma of the present invention, which is characterized in that a polymerization reaction system in the form of agar or powder is sufficiently stirred and mixed to form an aromatic polyamide with a high degree of polymerization having a logarithmic viscosity (η1r1h) of 4 or more. This is achieved by a method for producing group polyamides.

In the present invention, p-phenylenediamine is used as the aromatic diamine used in the polymerization of the aromatic polyamide with a rosette orientation, while terephthalic acid chloride and/or 4,4
-Biphenyldicarboxylic acid chloride is used.

Therefore, the aromatic polyamide obtained by the present invention is mainly composed of the following repeating units A and/or B, and a typical example thereof is poly p-phenylene terephthalamide.

In the present invention, in addition to the aromatic diamine and aromatic dicarboxylic acid dihalide, a third component is copolymerized within a range that does not essentially change the properties of the polymer, for example, in a proportion of about 10 mol% or less of the polymerized monomer. You may. The third component is preferably an aromatic diamine or an aromatic dicarboxylic acid, but may also be an aliphatic compound. Suitable third components include, for example, 2,6-naphthylenediamine, 4,4''
-diaminodiphenyl ether, 2,6-naphthalene dicarboxylic acid chloride, and the like.

The organic polar solvent used in the polymerization reaction in the present invention is
Dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-methylcaprolactam (NMCL)
), tetramethylurea (TMU), and the former two, DMAc and NMP, are particularly preferred. If necessary, a solvent inert to the polymerization reaction may be used as a diluent, such as methyl ethyl ketone, cyclohexanone, tetrahydrofuran,
Benzene, heptane, dimethyl sulfoxide, tetramethyl sulfone, etc. may be present, but compounds active in the polymerization reaction and added as terminators, such as water, primary or secondary amines, isocyanates, etc., are not suitable for polar solvents. It is desirable that the amount is very small, approximately several hundred or several thousand Ppm or less. In the present invention, among the organic polar solvents (hereinafter referred to as the solvent of the present invention), in the case of N-methylpyrrolidone, 1.5% by weight or more and less than 5.0% by weight, and in the case of other solvents, 1. 5-8. Calcium chloride (Ca
Cl2).

If the content of calcium chloride in the solvent system is less than 1.5% by weight, the degree of polymerization of the obtained polymer may not be sufficient, or the polymerization reaction must be carried out at a very dilute concentration to obtain a polymer with a high degree of polymerization. On the other hand, when the above upper limit is exceeded, the effect is small compared to the amount added, and calcium chloride itself or impurities contained in calcium chloride often have an undesirable influence on the polymerization reaction. A particularly preferable calcium chloride content is 1. Heel volume % or more 5. The volume is less than %. Calcium chloride can be used by being dissolved or partially suspended in the solvent or diamine solution specified in the present invention.

Further, a part of the calcium chloride to be added can be added at the same time as the diacid halide or after the start of the polymerization reaction. In order to avoid inhibiting the polymerization reaction, the calcium chloride used in the present invention is preferably as anhydrous as possible, or it is preferably dissolved in the solvent of the present invention and then dehydrated using a drying agent such as molecular sieves or azeotropic distillation. .

However, this does not apply when a terminator or the like is intentionally included. As already mentioned, generally, as a method of improving the dissolving power of an organic polar solvent, it is known to add a metal halide heptaide salt of Group 1 and/or Group II of the periodic table, such as lithium chloride. However, in the present invention, metal halide salts other than calcium chloride, such as lithium chloride,
Not only is it economically disadvantageous, but it is also less cost effective than calcium chloride, so it is not preferred.

The monomer concentration (that is, the amount of each component charged) in the polymerization reaction of the present invention should be 4 to 15% by weight in terms of the concentration of the polymer produced in the polymerization system.

If it is less than 4% by weight, the amount of polymer produced will be small relative to the processing chemicals used, and if it exceeds 15% by weight, not only will it not be possible to obtain a polymer with a high degree of polymerization, but the reproducibility of the degree of polymerization will also be poor. Not suitable for industrial use.

There are no particular restrictions on the polymerization temperature, but the starting temperature is usually -25°C.
A temperature range of -100°C, particularly preferably -15°C - 2(s) is used.

The temperature after the start of the reaction is 10C to 10σC1, preferably 2(
6CrC is suitable. In the present invention, the polymerization reaction system gradually becomes viscous after the start of polymerization, and eventually takes on the form of a slurry, paste, agar, or powder (so-called okara-like). Sufficient stirring and mixing is added to such a polymerization reaction system to give a kneading effect and the polymerization reaction is carried out. Therefore, in the present invention, it is important to use a seconder as a polymerization reaction apparatus capable of sufficiently stirring and mixing the above-mentioned polymerization reaction system at least in the latter half of the polymerization reaction.

Specific examples of such a seconder include a single-screw or twin-screw extrusion batch-type or continuous-type seconder mixer, a screw reactor, a reciprocating rotary reactor, a potator, a bag mill, an auger machine, and a gear compounder. , Co-kneader, Henschel mixer, etc. In the present invention, such stirring and mixing using a seconder is continued until the logarithmic viscosity (ηInh) of the polymer reaches 4 or more (preferably 5 or more) to obtain a polymer with a high degree of polymerization.

After the polymerization has been completed, the polymerization reaction system can be washed with water, acetone 9, etc. as necessary after adding a non-solvent such as water to isolate the polymer. Further, hydrogen halide produced as a by-product in the polymerization reaction can be neutralized with CaO, Ca(0H)2, CaCα, etc. to obtain a useful composition. Such compositions include those that form optically anisotropic solutions and utilize the solution properties to produce useful molded articles. Effects of the Invention According to the present invention as described above, a high degree of polymerization polymer having an logarithmic viscosity (ηIrlFl) of 4 or more, preferably 5 or more can be produced without using hexamethylphosphoramide, which is problematic in terms of occupational hygiene. A p-phenylene terephthalamide aromatic polyamide can be produced economically.

That is, by carrying out the present invention, it is possible to achieve a high degree of polymerization with an logarithmic viscosity (ηInh) of 4 or more, which has not been previously reported in a salt-added organic polar solvent system, without using hexamethylphosphoramide, which is considered harmful. The poly p-phenylene terephthalamide aromatic polyamide can be economically advantageously produced. That is, by carrying out the present invention, it is possible to reduce the logarithmic viscosity (ηInh) 4 without using hexamethylphosphoramide, which is considered to be harmful, and which has not been previously reported in a salt-added organic polar solvent system.
The above-mentioned aromatic polyamide based on poly p-phenylene terephthalamide having a high degree of polymerization can be produced with good reproducibility and at low cost. The poly p-phenylene terephthalamide aromatic polyamide thus produced is formed into fibers, films, fibrids, etc. by a wet method, a dry method, a wet method after space discharge, or the like.

These molded products are widely used for both clothing and industrial materials, such as heat-resistant clothing, heat-resistant hoses, heat-resistant films, heat-resistant paper, heat-resistant adhesives, flame-resistant wall cloth, flame-resistant curtains,
Comparative Examples 1 to 3 CaCl was used as a polymerization solvent in exactly the same manner as in Example 1.
A polymerization reaction was carried out in the same manner except that dry NMP not containing 2 was used.

However, as soon as TPC is added, the polymerization reaction system takes full advantage of its characteristics in the fields of phase separation filters, rubber reinforcing materials for tires, belts, airbags, etc., and resin reinforcing materials.

Examples Examples and comparative examples are shown below to specifically explain the present invention. The logarithmic viscosity (ηInh), which is a guideline for the degree of polymerization shown in the examples, C=0.
A solution dissolved at 5 g/d1 was measured at 30° C. using a conventional method.

Examples 1 to 4 Nitrogen was flowed into the interior of a 100 to 300 wtt separable flask having a high-speed rotating stirring blade, a dry nitrogen inlet and an inlet, and a raw material inlet while heating the flask from the outside to thoroughly dry the flask.

Molecular sieves contain 4% calcium chloride (C) by weight.
N-methylpyrrolidone (NMP) containing aCl2) was dried. Add p-phenylenediamine (PPDA) to the above NMP containing Cacl2 to the following concentration.
After cooling to 0° C., the following amount of terephthalic acid chloride (TPC) powder was added and vigorously stirred.

The terephthalic acid chloride dissolved quickly and uniformly, and the polymerization reaction system gradually became opaque and viscous, making stirring difficult. The contents were transferred to a two-screw kneader (PlastOgr'Aph, Brabender) and thoroughly kneaded. The reaction product was precipitated with water, washed with water and dried to isolate the polymer, and its logarithmic viscosity was measured.

The results are shown in Table 1 below. φ was formed and the mixture became cloudy yellow.

The results are shown in Table 2 below. Comparative Examples 4 and 5 In exactly the same manner as in Example 1, 1% by weight of C was added as a polymerization solvent.
A polymerization reaction was carried out in the same manner except that M2 containing acl2 was used.

The results are shown in Table 3. Examples 5 and 6 A polymerization reaction was carried out in the same manner as in Example 1 except that dried NMP containing 2.3% by weight of CaCl2 was used as the polymerization solvent.

The results are shown in Table 4. Comparative Examples 6 and 7 In the same manner as in Example 2, 1% by weight of CaCl2 was added as a polymerization solvent.
After the polymerization reaction, the polymerization reaction was carried out in the same manner using a stirring blade without being transferred to a second mite.

The results are shown in Table 5. Example 7 In exactly the same manner as in Example 2, only the polymerization solvent was added to 3
Dimethylacetamide (DM) containing wt% Cacl2
, Ac), and 35 ml of this was used for polymerization reaction.

The polymer concentration in the polymerization composition is 6. The obtained polymer had a ηInh of 5.1. Example 8 The inside of a separable flask of 100 to 300 ml, which had a stirring blade rotating at high speed, an inlet and an inlet for dry nitrogen, and a raw material inlet, was thoroughly dried by flowing nitrogen while heating the flask from the outside.

Calcium chloride (C) containing 3% by weight of molecular sieves
dimethylacetamide (DMAC) containing aCl2) was dried. Next, 16.22 g of p-phenylenediamine (PPDA) was dissolved in 35 mt in DMAC containing the above CaCl2, and after cooling to 0°C, 1.500 g of terephthalic acid chloride (TPC) powder was added to initiate a polymerization reaction. Further, 1.552 gf) TPC was added and vigorously stirred.

The terephthalic acid chloride dissolved quickly and uniformly, and the polymerization reaction system gradually became opaque and viscous, making stirring difficult. The contents can be quickly transferred to a double-screw kneader (Braber).
Kler PlastOgraph) and further 6
The powder was thoroughly kneaded, and the powder was left to stand for three more times. The polymer concentration in the resulting polymer composition was 8.7%. The reaction product was precipitated with water, washed with water and dried to isolate the polymer, and the logarithmic viscosity of the polymer was measured, and the logarithmic viscosity of the polymer was found to be 5.5.

Examples 9 to 11 In exactly the same manner as in Example 1, only diacid halide was added to terephthalic acid chloride (TPC) in the following proportions.
and 4,4'-biphenyldicarboxylic acid chloride (BP
The weight results are shown in Table 6 in the same manner except that C) was used.

Claims (1)

[Claims] 1 In producing a bulk aromatic polyamide by polymerizing P-phenylenediamine and terephthalic acid chloride and/or 4,4'-biphenyldicarboxylic acid chloride in an organic polar solvent system, (a) N - Methylpyrrolidone and 1.5% by weight or more based on the solvent 5.0
in a solvent system containing less than % by weight of calcium chloride, or
(b) A solvent whose main component is at least one selected from dimethylacetamide, N-methylcaprolactam, and tetramethylurea, and 8.0% by weight or more of 1.5% by weight or more based on the solvent.
Each reaction component is charged into a solvent system containing calcium chloride in an amount of 4% to 15% by weight or less to cause a polymerization reaction, and after the start of the polymerization, , sufficiently stirring and mixing the polymerization reaction system in the form of slurry, paste, agar, or powder in a kneader to form an aromatic polyamide with a high degree of polymerization having a logarithmic viscosity (ηinh) of 4 or more. A method for producing a rose-oriented aromatic polyamide characterized by: