JPH023809B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION This invention relates to an improved method for producing para-oriented aromatic polyamides. More specifically, the present invention relates to a method for economically producing para-oriented aromatic polyamides with a high degree of polymerization, particularly poly-p-phenylene terephthalamide-based aromatic polyamides, safely and in accordance with occupational health. Prior Art So-called fully aromatic polyamides have excellent thermal,
Because of its mechanical properties, it is useful as a resin for producing fibers, films, fibrids, 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, 42-17510). However, para-oriented aromatic polyamides, in particular poly-p-phenylene terephthalamide (PPTA)-based aromatic polyamides, consist essentially of repeating units in which the amide group is bonded to the para position of the aromatic group.
It is poorly soluble or insoluble in many organic solvents, and it is said that it is difficult to produce a polymer with a high degree of polymerization using interfacial polymerization or oligomer polymerization. Furthermore, even if low-temperature solution polymerization is used, dimethylacetamide, N-methylpyrrolidone, N-
Among so-called organic polar solvents such as methylcaprolactam and tetramethylurea, it is known that hexamethylphosphoramide and a mixed solvent system of hexamethylphosphoramide and other organic polar solvents give a polymer with a high degree of polymerization. On the other hand, as a method of improving the dissolving power of organic polar solvents, a method of adding a metal halide salt of Group 3 and/or Table 1 of the periodic table is known (Japanese Patent Publication No. 16027/1983). Polymerization of poly-p-phenylene terephthalamide in this salt-added organic polar solvent system has already been investigated, but a polymer with a high degree of polymerization has not been obtained (LBSokolov et al.
Vysokomol. Soyed. A12 , 2185-2198, 1970). On the other hand, the degree of polymerization sufficient to obtain high-performance molded products from poly-p-phenylene terephthalamide (PPTA)-based polymers cannot be unconditionally determined, but it is especially important to prepare molded products such as fibers by the measurements described later. The logarithmic viscosity (ηinh) measured by the method is required to be 4.0 or more (Japanese Unexamined Patent Publication No. 47-43119). However, it has recently been revealed that hexamethylphosphoramide poses occupational health problems and requires special precautions when using it (Chemical and Engineering News, Sept 29, 2013).
(1975, p. 17). OBJECTS OF THE INVENTION The main object of the present invention is to produce para-oriented poly-p-phenylene terephthalamide (PPTA) with a high degree of polymerization in an industrially hygienic and economically advantageous manner.
The purpose of the present invention is to produce aromatic polyamides based on aromatic polyamides. Structure of the Invention The above-mentioned object is to polymerize p-phenylenediamine and terephthalic acid chloride and/or 4,4'-biphenyldicarboxylic acid chloride in an organic polar solvent system to produce a para-oriented aromatic polyamide. In particular, when manufacturing aromatic polyamides based on poly-p-phenylene terephthalamide (PPTA), a solvent containing at least one selected from dimethylacetamide, N-methylcaprolactam, and tetramethylurea as a main component and the solvent Against, 1.5
The polymerization reaction was carried out in a solvent system containing ~8.0% by weight of calcium chloride (CaCl ₂ ), and after the start of the polymerization, the polymerization reaction system, which was in the form of a slurry, paste, agar, or powder, was sufficiently stirred and mixed. This is achieved by the method for producing a high degree of polymerization aromatic polyamide of the present invention, which is characterized in that the aromatic polyamide has a high degree of polymerization and has a logarithmic viscosity (ηinh) of 4 or more. In the present invention, p-phenylenediamine is used as the aromatic diamine used in the polymerization of para-oriented aromatic polyamide. On the other hand, as the aromatic dicarboxylic acid dihalide, terephthalic acid chloride and/or 4,4'-
Biphenyldicarboxylic acid chloride is used. Therefore, the aromatic polyamide obtained by the present invention has the following repeating units (A) and/or (B): The main focus is In addition, in the present invention, in addition to the above-mentioned aromatic diamine and aromatic dicarboxylic acid dihalide, a third component may be copolymerized in a proportion of about 10 mol % or less of the polymerized monomer. This 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-naphthylene diamine, 2,6-naphthalene dicarboxylic acid chloride, and the like. The organic polar solvent used in the polymerization reaction in the present invention is dimethylacetamide, N-methylcaprolactam, and tetramethylurea, with dimethylacetamide and N-methylpyrrolidone being particularly preferred. These solvents can be used alone or in combination of two or more. If necessary, a solvent inert to the polymerization reaction, such as methyl ethyl ketone, cyclohexanone, tetrahydrofuran, benzene, heptane, dimethyl sulfoxide, tetramethyl sulfone, etc., may be present as a diluent. Compounds to be added, such as water, primary or secondary amines,
It is desirable that the amount of isocyanate, etc. is very small, approximately several hundred or several thousand ppm or less based on the polar solvent. In the present invention, the organic polar solvent (hereinafter referred to as
1.5 to 8.0% by weight relative to (referred to as the solvent of the present invention)
of calcium chloride (CaCl ₂ ). Calcium chloride content in the solvent system is 1.5
If the amount is less than 8% 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, and if it exceeds 8% by weight, the amount of addition may be In comparison, the effect is small, and calcium chloride itself or impurities contained in calcium chloride often have an undesirable effect on the polymerization reaction. The preferred content of calcium chloride (CaCl ₂ ) is 1.8% by weight or more and less than 5.0% by weight. Calcium chloride can be used by being dissolved or partially suspended in the solvent or diamine solution of the present invention. Also, a portion 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, the method of adding metal halide salts of Groups and/or Groups of the Periodic Table, such as lithium chloride, is generally known as a method of improving the dissolving power of organic polar solvents. In the invention, metal halide salts other than calcium chloride,
For example, lithium chloride and the like are not only economically disadvantageous but also less cost effective than calcium chloride, so they are not preferred. The monomer concentration in the polymerization reaction of the present invention is preferably 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, it will not be possible to obtain a polymer with a high degree of polymerization, or the reproducibility of the degree of polymerization will be poor. The polymerization temperature is not particularly limited, but the starting temperature is usually -25°C to 100°C, particularly preferably -15°C to 20°C. The temperature after the start of the reaction is 10℃~
A temperature of 100°C, preferably 20°C to 60°C is suitable. In the present invention, the polymerization reaction system takes the form of slurry, paste, agar, or powder after the start of polymerization, but in the present invention, in order to produce a polymer with a high degree of polymerization, such a polymerization reaction system is further stirred and mixed thoroughly. The polymerization reaction is carried out while adding a polymerization effect. Therefore, in the present invention, it is important to use a polymerization reaction apparatus capable of sufficiently stirring and mixing the polymerization reaction system as described above. Specific examples include single-screw or twin-screw extrusion followed by batch or continuous kneader mixers, screw-type reactors, reciprocating rotary reactors, potators, bag mills, auger machines, gear compounders, co-kneaders, and hens. There is a method using a shell mixer or the like. Such stirring and mixing is continued until the logarithmic viscosity (ηinh) of the polymer reaches 4 or more to obtain a polymer with a high degree of polymerization. After adding a non-solvent such as water to the polymerization reaction mixture system, the polymer can be isolated by washing with water, acetone, etc. as necessary. In addition, hydrogen halides produced as by-products in the polymerization reaction are converted into CaO, CA(OH) ₂ ,
It can be neutralized with CaCO ₃ or the like to provide useful compositions. 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 poly-p-phenylene terephthalamide system having a high degree of polymerization with an logarithmic viscosity (ηinh) of 4 or more can be used without using hexamethylphosphoramide, which is problematic in terms of occupational health. Aromatic polyamides can be produced economically. That is, by carrying out the present invention, poly-p-
Phenylene terephthalamide-based aromatic polyamide can be produced with good reproducibility. 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 curtains, flame-resistant wall cloth, and flame-resistant carpets. Its characteristics are fully demonstrated in the fields of rubber reinforcement materials for tires, belts, airbags, etc., and resin reinforcement materials. Examples Examples and comparative examples are shown below to specifically explain the present invention, and the logarithmic viscosity (ηinh), which is a guideline for the degree of polymerization shown in the examples, is 98.5% by weight of concentrated sulfuric acid with a concentration of C = 0.5 A solution dissolved in g/d was measured at 30°C using a conventional method. Logarithmic viscosity (ηinh) = lnηrel/C Example 1 The inside of a 100-300ml separable flask, which has a stirring blade rotating at high speed, an inlet/outlet for dry nitrogen, and a raw material inlet, was thoroughly dried by flowing nitrogen while heating it from the outside. . Dimethylacetamide (DMAC) containing 3% by weight of calcium chloride (CaCl ₂ ) was dried with molecular sieves. Next, 1622 g of p-phenylenediamine (PPDA) was dissolved in 35 ml of the above DMAC containing _CaCl2 , and after cooling to 0 °C, 1500 g of terephthalic acid chloride (TPC) powder was added to perform a polymerization reaction. Then, 1552 g of TPC was added and stirred vigorously. Terephthalic acid chloride quickly and uniformly dissolved, and the polymerization reaction system gradually became opaque and viscous, making stirring difficult. The contents were quickly transferred to a twin-screw kneader (Plastograph, Brabender), thoroughly kneaded for an additional 60 minutes, and left to stand for an additional 30 minutes. 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. Example 2 A 300 ml separable flask having a stirring blade rotating at high speed, a dry nitrogen inlet/outlet, and a raw material inlet was thoroughly dried by flowing nitrogen while heating the inside of the flask from the outside. 150 ml of tetramethylurea (TMU) dehydrated and dried with molecular sieves was added. Absolutely dried calcium chloride (CaCl ₂ ) corresponding to 7% by weight of the input TMU was ground and mixed in a mortar, and dissolved as much as possible at an internal temperature of 60°C. 3.24 g of paraphenylene diamine (PPDA) was mixed and dissolved in the obtained CaCl ₂ /TMU mixture, and after the internal temperature was cooled to 5° C., 6.15 g of terephthalic acid chloride ground in a mortar was added and stirred vigorously.
When it became difficult to stir the polymerization reaction system, the contents were transferred to a small kneader and further kneaded thoroughly. The polymer isolated by precipitating the reaction product in water, washing with water, and drying had ηinh of 4.7. Example 3 A polymerization reaction was carried out in exactly the same manner as in Example 2 except that 150 ml of TMU was replaced with 120 ml of N-methyl-ε-caprolactam (NCL) to obtain a polymer with ηinh of 5.6.

[Claims]

1. A process for producing a sulfonated and deactivated latex of a low unsaturated elastomer of butyl rubber or EPDM, comprising: (a) providing a cement of an elastomer and a volatile solvent; (b) converting the elastomer cement to an acylsulfone sulfate. (c) inactivating the sulfonated cement with at least a stoichiometric amount of an organic epoxide containing at least one reactive oxirane group; (d) using an anionic surfactant (c) a stable latex by forming the product of step in a neutralized form into an aqueous emulsion, neutralizing said product with a weak base before or after emulsification, and (e) subsequently stripping off excess water and solvent. A method comprising the steps of obtaining an emulsion.