JPS58154756A - Production of aromatic polyamide solution - Google Patents

Abstract

PURPOSE:To industrially produce the titled solution having improved heat resistance, flame retardance and mechanical characteristics as well as improved solution characteristics such as solubility, solution stability, etc., by using a specified arom. polyamide, a specified org. polar solvent and chlorides of Li, Ca and Mg. CONSTITUTION:A polymn. reaction is conducted by using a monomer combination consisting of tere(iso)-phthaloyl chloride and p- or m-phenylendiamine in an amount corresponding to the skeleton composition of an arom. polyamide having a repeating unit of the formula (wherein Ar1, Ar2 are each p- or m-phenylene) in an org. solvent which does not contain chlorides of Li, Ca and Mg. Hydrogen chloride as a byproduct is neutralized with chloride, hydroxide or carbonate of Li, etc. to obtain the titled soln. Alternatively, said arom. polyamide is re-dissolved in an org. polar solvent, such as N-methyl pyrrolidone, contg. a chloride of Li, etc. to obtain the titled soln.

Description

Detailed Description of the Invention Field of Application of the Invention The present invention d1 Fibers suitable for spinning or forming into films, etc., and having excellent properties such as heat resistance, strong flammability, and high mechanical properties;
The present invention relates to a method for producing an aromatic polyamide solution that can be molded into a film or the like and has excellent fluidity and stability.

More specifically, the general formula -HN-A rlNH-CO-
Mrl-CO- (However, Mrl, Ar1ki P-
phenylene group or m-phenylene group), 6 of the total amount of Arl.
The present invention relates to a method for producing an aromatic polyamide solution comprising a random copolymerized aromatic polyamide in which 0 to 70 moles are P-phenylene groups, a specific organic polar solvent, and a specific metal chloride.

Conventional fully aromatic polyamides that provide heat-resistant molded products include:
Although poly-m-phenylene isophthalamide has already been produced industrially, the heat resistance, flame retardance, and mechanical properties of films, fibers, and films formed from this polymer are not necessarily satisfactory. These properties can be improved by copolymerizing monomers having a P-phenylene skeleton with good chemical structure symmetry. However, as seen in Japanese Patent Publication No. 45-33195 and Kogyo Kagaku 11:71゜448 (sssa) K, polymers made from m-phenylene diamine and terephthalic acid chloride, for example, can be dissolved in organic solvents in very acid baths. It is said that it has poor stability and is difficult to spin and form.

OBJECTS OF THE INVENTION The present invention provides a method for industrially producing a nine-aromatic polyamide solution with improved properties such as solubility and solution stability.

Structure of the Invention The present invention consists of a repeating unit represented by the general formula %, and m
It is a phenylene group, and the sand residue is a phenylene group.
In producing a solution of a random copolymerized aromatic polyamide consisting of an aromatic polyamide, a specific organic polar solvent, and a specific metal chloride, a) an amount corresponding to the polymer skeleton composition of (a) above; P-phenylenediamine and (J' / n vn -y The reaction is carried out and the by-product hydrogen chloride is subsequently neutralized with an oxide, hydroxide or sulfuric acid salt of lithium, calcium or magnesium to form the above solution, or An aromatic polyamide having a polymer skeleton composition is placed in solution in the organic polar solvent of (b).
This method is characterized in that it is redissolved in a foreground containing chloride of @) to form a solution.

11I of the present invention! The aromatic polyamide having repeating units represented by the above general formula, which constitutes the liquid, can be synthesized by any conventionally known method. In other words, the elevation polycondensation method C@Refer to Publication No. 1835-13247),
Oligomer polymerization method (see 4I Publication No. 47-10861) or low-temperature solution polymerization method (specific f1s36-14199)
For the purpose of obtaining a polymer for a polymer lid, a low-temperature solution polymerization method is preferred.

In the polymer having repeating units represented by the above general formula, 60 to 70 moles of the sum of mrl+mr in the formula are P-phenylene groups, and the remaining 40 to 30 moles are m-phenylene groups. If the ゎP-phenylene group, which is required to be a group, contains .0 mol, the solubility of the polymer in a solvent will be poor and the heat resistance of the polymer will be poor.

Furthermore, if the total amount of Arl and Arz exceeds 70 moles of P-phenylene groups, the solubility of the polymer in the solvent will be poor and a uniform solution will not be obtained.

In the present invention, the degree of polymerization of the random copolymerized aromatic polyamide is determined by the intrinsic viscosity (o, sr/
111) measured at 30°C at a concentration of 1oo- is preferably 1.0 or more, and 4IK is more preferably 1.7 or more.

The aromatic polyamide of the present invention may contain a counterfeit copolymer component (third component) to the extent that the characteristics of the present invention are not impaired.

Examples of organic polar solvents constituting the solution of the present invention include N-methylpyrolide 7 (NMP), N,N-dimethylacetamide (DMA), and dimethylsulfoxide (
0M80), N,N-dimethylformamide (DMF
), N, N, N', N'-tetramethylurea ('I
'MU)T.

or a mixture thereof.

NMP, DMA, DMSO or a mixture thereof in such a solvent is preferably used.

It is preferable that the liquid of the present invention contains a small amount of chloride of a metal of group 1 and/or group [of the periodic law, for the purpose of further improving solubility.

Lithium chloride, calcium chloride, and magnesium salt are particularly preferably used.

Such a solution can be prepared by (a) a method involving a polymer formation reaction (polymerization reaction) or (b) mixing and redissolving the aromatic polyamide with the organic polar solvent or the organic polar solvent containing the above-mentioned metal halides. It can be manufactured by a method.

In order to produce the composition of the present invention accompanied by a polymer reaction, m-phenylenediamine, p-phenylenediamine, f-sophthalic acid chloride, terephthalic acid chloride, and if necessary, This can be carried out by allowing a small amount of copolymerization components to withstand, preparing the aromatic polyamide by a known low II liquid polymerization method, and then neutralizing part or all of the dichlorohydrogenide. . The neutralizing agent C is an oxide of a metal of Group 1 and/or Group `` of the periodic table.

Hydroxides, carbonates, etc. can be used. Preferred are oxides, hydroxides, and carbonates of lithium, calcium, and magnesium. The water produced by the neutralization reaction does not impair the characteristics of the liquid of the present invention.

When producing the compositions of the present invention with polymer-forming reactions, the choice of solvent is superpositional. General K.

TMU, NMP, and DMA are excellent as polymerization solvents, and NMP has excellent solubility. Therefore, NMP is a comprehensive K
Most preferred.

On the other hand, when using the redissolution method, it is preferable to use the aromatic poly-1J amide that has been sufficiently finely ground in advance and has a low degree of crystallinity. When mixing with the organic polar heating medium, it is preferable to thoroughly knead the mixture at a temperature below a suitable temperature prior to dissolution as described in Jibun No. 1841-4461.

After uniform kneading, the mixing system is heated to an excessive temperature to promote dissolution. The preferred temperature varies depending on the type of solvent, the mixing ratio, and the content of the metal chloride, but it is generally IQ-150°C.

In order to obtain a good molded product, the aromatic polyamide in the composition of the present invention has a content of 7 to
2s weight is preferred, and 16 to 20% is particularly preferred.

Also lithium.

The chloride of metals such as calcium and magnesium preferably has a coulometric capacity of 10 or less. Generally speaking, the higher the metal chloride content, the higher the solubility and dissolution rate.

Although solution stability etc. tend to increase, solution viscosity also increases, and for example, coagulation during molding deteriorates, and generally lO
If it exceeds 1, it becomes difficult to mold.

Effects of the Invention According to the present invention, a transparent and fluid aromatic polyamide solution is obtained, and fibers, films, and resins formed from the solution exhibit excellent heat resistance, flammability, and mechanical properties. have.

Moreover, it has excellent solubility such as solubility, dissolution rate, and solution stability, and Maku molded products have insufficient heat resistance, which is insufficient for molded products made from poly-iw+ -phenylene isophthalamide.
! It can be used in fields where flammability and mechanical properties are required.

Conventionally, for such purposes, materials with poor structural symmetry, such as m-
90 (411 Ko 1845-3) by copolymerizing the phenylene skeleton.
No. 3195), or the methyl t III J
A fully aromatic polyamide with a P-phenylene skeleton (see 4I Publication No. 48-32195) has been proposed.
The present invention introduces a P-phenylene skeleton, which has good structural symmetry and is easily available industrially, into poorly soluble polyamides such as poly-m-phenylene terephthalamide and poly P-phenylene isophthalamide. This is extremely significant as it improves the above-mentioned properties.

Fibers and films produced from the solution of the present invention.

Various molded products such as wood fir, fibrids, powder etc. have excellent properties and are used for example as industrial materials, insulating laminated structure materials, festivals, etc.
Covering materials etc. can be obtained.

In particular, fibers and fibrids are tire cords.

It is extremely useful as a resin reinforcement material, heat-resistant insulation material or F cloth.

EXAMPLES The present invention will be explained with reference to Examples below. In the examples, the intrinsic viscosity ηiak was measured in sulfuric acid after the polymer was isolated from the composition, and the polymer performance was 0. ! Values measured at 30'C with ly/1oa-. All divisions and companies are expressed in parts by weight.

Example 1 11-phenylenediamine S,4
The SO part and 3.244 parts of P-phenylenediamine were dissolved in 1211 parts of dehydrated and purified MP, and after bringing the internal temperature to -20°C by external cooling, 18.372 parts of terephthalic acid chloride crushed in a mortar was added at once. . The reaction proceeded rapidly and a clear viscous liquid was obtained. After 4 hours, 6.686 parts of lithium carbonate was added to this polymerized viscous liquid, and 70 to 100 parts of lithium carbonate was added.
'C was kept and photons were neutralized. The resulting composition was 14
It was a transparent viscous material containing 171nh 3.1% by weight of polymer, 5.1% lithium chloride, and 2.2% water, and was suitable for molding.

The dope was hot-spun using an aqueous calcium chloride solution as a coagulation bath. This undrawn yarn was washed with warm water under tension and further hot-stretched at a temperature of a4oc. The quality of this thread is the strength (r
/no)/elongation@/initial modulus (f/D.) were 11.1/1@ and strength/250, respectively.

Example 2 Using the same reactor as in Example 1 and using the same operation, 1.442 parts of m-phenylenediamine z, 5s411 and P-7 ethylenediamine was treated with terephthalic acid μ in -IS'C in 35 parts of NMP. Added 8162 parts of Ride, 14M within 5 minutes after addition.
25 parts of P capsule were added. After 2 hours, 2.25 parts of calcium oxide crushed in a mortar was added, and the temperature was maintained at 70 to 90°C to neutralize by-product hydrogen chloride.

This composition exhibited good strength solution stability and good spinnability at 100°C. The ηi+xb Fi of the polymer was 2.9.

Comparative Example 1 In the same manner as in Example 1, m-phenylenediamine 2.16
When 3 parts of NMP are reacted with 7s% of terephthalic acid chloride in 26 parts of NMP at 0°C, after the start of the reaction, the system after aSS is K.
After 10 minutes, the mixture started to thicken and became cloudy and solidified. 1.48 f of lithium carbonate was added to this polymerization reaction mixture system, and 70
Although most of the mixture was redissolved by stirring at ~90°C for 8 hours, a completely transparent composition was not obtained due to the presence of insoluble matter.

The fiber obtained from this in the same manner as in Example 1 has a strength (f
/D・)/Elongation−/Initial modulus Cf/D・) is 2. tJ/10.0/60.

Ratio 11 Same as Example 1 m-phenylenediamine 1.08
1. 1.082 parts of P-phenylenediamine in NMP 4
N i @ medium Q'C, terephthalic acid chloride 4.07
When reacted with 1 part, it became 4#i opaque 10 minutes after the start of polymerization, and gradually turned cloudy into a paste-like state. Add 1.55 parts of lithium vertical oxide to this polymerization-completed mixed system and heat at 70 to 100°C.
Although the mixture was heated and stirred, a completely uniform and transparent composition could not be obtained and could not be used for molding.

Comparative Example 3 Same as Example 1, wr-phenylenediamine 1.0
81 parts, 1.011 parts of P-phenylenediamine, 30 parts of NMP, 2.040 parts of isophthalic acid chloride,
2.040 parts of terephthalate tetralide were reacted at -14°C and neutralized after 4 hours with 1.485 parts of lithium carbonate to obtain a transparent viscous composition containing a polymer of ηink 2J. Although the spinning of this composition was relatively good, the yarn quality was poor in strength (f/D・)/elongation &@/initial modulus
o) Fi were 4.4/10.5/8 G, respectively.

Example 3 P-phenylenediamide 7!1.2 was prepared in the same manner as in Example 1.
44@woNMP 50 parts -15℃ Teisophthalic acid dichloride 4.584 parts, terephthalic acid dichloride 1.5
After 3 hours, 3.0 parts of calcium carbonate was added.
The composition obtained by neutralizing with 1 part contained a polymer with η1nk of 3.1 and had good solubility and solution stability.

A polymer prepared in exactly the same manner as in Example 1 and having a 9η1 mb of 2.7 was isolated from the composition by reprecipitation in water. Parts of dehydrated and dried powders X and O having a mesh size of 6 or less were cooled to 0°C, stirred with 30 parts of 9NMP for 3 hours, and gradually heated to @0.
A composition with a uniform viscosity was obtained by stirring for 6% at ~so°C.

Comparative Example 3 3.0 parts of powder of 60 mesh or less of poly-phenylene terephthalamide of VTNH19 was stirred with 50 parts of NMP in exactly the same manner as in Example 5, but a uniform composition could not be obtained. .

Example 5 Using a polymer having the same composition as in Example 1, 5.0 parts of polymer, 0.2 part of calcium chloride,
A good composition was obtained from 30 parts of NMP.

Claims (1)

[Scope of Claims] (a) A paper made from the <〉 return unit represented by the general formula % formula %, such that the total amount of mu r1 and Arl in the sand return unit is 10 to 70 moles P-
(b) N-methylpyrrolidone,
N,N-dimethylacetamide, dimethylsulfoxide. N,N-dimethylformamide, and N,N,N',N
A method for producing an aromatic polyamide $1110 comprising at least one organic polar solvent selected from the group consisting of '-tetramethylurea, and (C) a chloride of lyticum, calcium or magnesium, comprising: a) the above (a); ) in an amount corresponding to the polymer skeleton composition of
Using a combination of monomers consisting of phenylene diane and/or half enelene diane and terethalic acid chloride and/or inphthalic acid chloride, the above (,)
The polymerization reaction is carried out in a chloride-free latent medium, and then the by-product hydrogen chloride is converted into oxides of lithium, calcium or magnesium. by neutralizing with hydroxide or carbonate), the fl.
or (1) Aromatic polyamide having the polymer skeleton composition of (&) above is dissolved in the organic polar 111 medium of (b) in a state containing the chloride of (▀) in the solution. A method of making mold by redissolving it and making it into droplets.