JPS6029739B2 - Aromatic polyamide crystalline complex and method for producing aromatic polyamide crystalline complex - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a melt-formable aromatic polyamide crystalline collar body.

In recent years, aromatic polyamide polymers have been widely used for clothing, materials, electrical insulation, etc. by being molded into fibers, films, resins, or papers due to their excellent heat resistance.

Conventionally, such aromatic polyamide polymers have extremely high melting points and cannot be melt-molded, and in order to be molded into fibers, films, or paper, the polymers must be prepared using dimethylformamide, N-methyl-2-pyrrolidone, tetramethylurea, etc. A so-called wet or dry molding method is employed in which the polymer solution is once dissolved in a polar organic solvent and the solvent is removed by extruding the polymer solution through a nozzle, die, or orifice into a liquid or gas stream.

However, this method requires expensive organic solvents;
It also has the disadvantage of requiring a large amount of expense for solvent recovery.

Compression molding of fine polymer powder has been attempted as a resin molding method, but it is difficult to produce uniform products. Against this background, the present inventors have conducted intensive research on a method for molding aromatic polyamide polymers at low temperatures without requiring a large amount of solvent, and have finally arrived at the present invention.

That is, the gist of the present invention is that 25q0 concentrated sulfuric acid 1
1 in 00cc. Relative viscosity when dissolved is 1.5~
5.5, a crystalline complex consisting of poly-m-phenylene isophthalamide and 2-pyrrolidone or caprolactam, and the above-mentioned poly-m-phenylene isophthalamide and 2-pyrrolidone or caprolactam are brought into contact to form a crystalline rust body, Next, 2-pyrrolidone or caprolactam not included in the crystals is removed to produce an aromatic polyamide crystalline rust body.

The crystalline key body of the present invention is a free-flowing substance, and it is thought that the aromatic polyamide and 2-pyrrolidone or caprolactam coexist in the crystal lattice to form a novel crystalline key body.

Such a crystalline body is a completely new chemical substance that has not been previously known to the world.

The method for manufacturing the crystalline coin body of the present invention will be specifically described below.

The organic solvent used in the production of the crystalline key body is 2-pyrrolidone or caprolactam, and it is preferable to use it alone, but water, benzene, methyl alcohol, ethyl alcohol, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, There is no problem in using a small amount of tetramethylurea mixed with the solvent. The form of the aromatic polyamide polymer to be used is not particularly limited, and any of powder, unoriented or oriented fibrous material shaped into fibers by a conventional method, film-like material, or resin-like material can be used. .

The degree of polymerization of the polymer is not particularly limited, but preferably has a relative viscosity of 1.5 to 5.5 (1.5 to 5.5 in 100 cc of concentrated sulfuric acid of 25 q0).
(measured in female concentration, the same applies hereafter). Industrially, it is preferable to form a crystalline polymer in a short time at a relatively low temperature, and for this purpose, the density of the polymer must be 1.3 or less, and the thermal history must be 35,000 or more and a thermal history of 30 minutes or more. It is desirable that the

Such a method of contacting an aromatic polyamide polymer with a solvent can be carried out by dissolving or absorbing the polymer at a temperature higher than the melting point of 2-pyrrolidone (24.6oo) or higher than the melting point of caprolactam (69o0); A solvent capable of dissolving caprolactam, preferably an organic solvent which does not swell or dissolves the aromatic polyamide polymer, is used in combination to dissolve or absorb the polymer.

At this time, the contact ratio between the polymer and 2-pyrrolidone or docaprolactam is such that two or more solvent polymers are preferably present in a molar ratio.

The temperature when bringing the polymer and the solvent into contact is room temperature, and after mixing both well, in the case of 2-pyrrolidone single solvent, 25q
It is preferable to use a range of 0 to 150 qo, and in the case of a single caprolactam solvent, a range of 7,000 to 15,000 qo.

Next, drying is performed to remove excess 2-pyrrolidone or caprolactam that is not contained in the crystalline body, but since the generated anchor has a low melting point, the drying temperature is lower than the melting point, preferably 130 oo or less in the case of 2-pyrrolidone. It is preferable to adopt a temperature condition of 110 qo or less, and in the case of caprolactam, 150 qo or less, preferably 130 qo or less.

In the case of a mixed solvent system, it is desirable to dry at a temperature of 150° C. or lower after performing a drying process such as centrifugal desolvation, oven filtration, filtration, or concentration.

Specifically, the armor body manufactured in this manner has the following characteristic values.

For example, polyphenylene isophthalamide powder with a relative viscosity of 3.2 is dissolved in caprolactam at a ratio of caprolactam/polymer 10/1 (weight ratio) for 20 minutes at 150 q0, and then vacuum dried at 12,000 ml. , the crystalline complex (
The properties of the complex obtained when this complex is obtained (hereinafter referred to as complex A) are as follows. The X-ray diffraction diagram of anchor A is shown in Table 1 and
As shown in the figure.

Table 1 clearly shows that poly(m-phenylene isophthalamide) has a crystal structure different from that of caprolactam.

The density was measured in decalin at 25°C and was 1.20.
It was g/m.

This varies from 1.19 to 1.2 foundation/ground depending on the rust formation conditions. The theoretical density of the untreated polym-phenylene isophthalamide fiber is 1.47 g/ground, and the actual density is 1.3 g/ground.

FIG. 2 shows the infrared absorption spectrum of Senitai A.

The melting point was determined by measuring a DSC curve using a PerkinElmer DSCO model at a heating rate of 10° C./min.

The results are as shown in FIG. 3, and an endothermic peak was observed at o for 15. Heat of fusion △ Kawama 12.7 Cal calculated from this
/g. This is much lower than the melting point (420° C.) of poly(m-phenylene isophthalamide) polymer, indicating that the crystalline coin body of the present invention is completely new. The dynamic viscoelasticity of Complex A is as shown in FIGS. 4 and 5, and FIG. 5 shows the temperature dependence of the dynamic loss rate.

From around 12pi0, n6 rises rapidly, and correspondingly, E' begins to fall sharply.

Measurement becomes impossible at temperatures above 150°C, and it is thought that flow occurs at this temperature range.

This phenomenon indicates the possibility of melt spinning and melt molding of the crystalline mirror of the present invention. When the solvent was removed from Tsuba body A by extraction with sea bream water, the molar ratio of polym-phenylene isophthalamide and caprolactam was 1:1.98 (=weight ratio 53:
47).

This value also changes depending on the conditions for forming the polymer, and a molar ratio of polymer to solvent of 0.17 to 1.98 can be obtained.

The results of thermogravimetric analysis are shown in Figure 6.
．． TGA curves were measured at a heating rate of 5° C./min. 15 is the melting point of mirror A, and 400 qo or more is the decomposition point of the polymer.

There is almost no weight loss up to 100 qo, but caprolactam soot is removed near the melting point and is almost completely removed at 30,000 qo.

The amount of solvent removed at this time was about 43%, which is almost the same as the extraction loss. The crystalline rust body of the present invention is particularly suitable as a starting material for fibers, films, nonwoven fabrics, binders, etc. by taking advantage of its low melting point.

In particular, an aromatic polyamide polymer in which a crystalline collar body is formed using oriented fibers is useful as it exhibits excellent performance as a binder for nonwoven fabrics. Further, since the amount of solvent is small (low-temperature molding is possible), it is easy to prepare a film, and it is possible to provide an aromatic polyamide having excellent properties as an electrical material at a low cost.

The method for extruding the crystalline collar body of the present invention into fibers or films is, for example, as follows. As mentioned above, the collar body of the present invention is in the form of a powder or pellet at room temperature, and melts and softens above a certain temperature. Above the melting temperature, it has a melt viscosity of 1 pipoise to 1 pipoise, depending on the degree of polymerization of the polymer and the amount of solvent present, and extrusion molding is possible. In this case, the amount of solvent coexisting is preferably 0.5 to 2.5 in terms of molar ratio per polymer, and if the amount of solvent exceeds this amount, the plasticizing effect becomes significant and melt extrusion is possible, but it is the same as gel extrusion. Therefore, the structure of the drawn product is close to that of wet extrusion, the strength is less than 1 g/d in the case of fibers, and the paper yarn speed has to be less than several tens of m/min, resulting in low productivity. The complex is then extruded through a nozzle, T-die, at a temperature of 500 degrees or more, preferably 10 degrees or more, of its melting temperature.

The extruded molded product can be washed once or without being rolled up.
It is shaped by stretching, drying or hot stretching. Note that washing and stretching may be performed at the same time or in the reverse order. In the case of fibers, it is possible to extrude at a rate of 10 h/min or more, and the drawn yarn already exhibits a high degree of orientation. Then, it is stretched 1 to 5 times in warm water at about 100 oo. After drying, the film is passed through a heating ramp heated to at least 3,000°C, preferably 330°C or higher, to crystallize it and stretch it by a factor of 4 times or less. In the aromatic polyamide polymer of the present invention, at least 75 mol% of the repeating structural units are m
The object of the invention is m-phenylene isophthalamide obtained by reacting phenylene diamine and isophthalic acid halide such as isophthalic acid chloride by solution polymerization or interfacial polymerization.

If the copolymerization component exceeds 25 mol %, the crystallinity of the resulting crystalline polymer will be markedly reduced, making it unfavorable for handling. The components to be copolymerized as necessary include p-phenylenediamine, benzidine, 44-diaminodiphenyl ether, 44-diaminodiphenyl sulfone, etc. as the amine component, and terephthalic acid chloride, 1.4 or 2, as the acid component.
．． These include dicarboxylic acid halides such as 6-naphthalene dicarboxylic acid chloride, diphenylsulfone 44-dicarboxylic acid chloride, and diphenylhenal-44 dicarboxylic acid chloride, or aminobenzoic acid halides. Further, if the number of metal ions such as calcium, lithium, aluminum, etc. contained in the polymer exceeds several thousand, a bell body with a different structure will be formed, so it is desirable that the number of metal ions is 200 or less.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the Examples.

Example 1 Powder of polym-phenylene isophthalamide having a relative viscosity of 3.4 was soaked in 2-pyrrolidone at a ratio of 2-pyrrolidone/polymer: 10/1 (weight ratio) for 15,000 hours for 2 hours, and the polymer was separated in a furnace. After that, vacuum drying was carried out for 5 hours at 0.0 and 2-hour Hg.

The X-ray diffraction diagram of this material shows 20=11.0o m, 17
．． 40v. s, 18.40w, 20.20w, 21.0
0w, 23.20v. s, 25.00s, 26.20m
A sharp absorption was observed at , 27.4 om. These are different from the absorption of polym-phenylene isophthalamide crystals. The boiling water extraction rate of the enantiomer is 37M%, and the melting point is 1
It was 30qo. Pass the coin body through the 10-hole connecting thread cap.
5000 and extruded with iron thread pressure 65k9/ground.

The spun yarn was wound at a speed of 20 plates/min.

The drawn yarn was fed into a washing machine with a length of 3 hours at 20 threads/min for 10 minutes.
While washing at 0qo, stretching was carried out at 1.9 degrees using a take-up roll at 3 hours/minute. The film was then passed through a dry loaf at 150° C. and a hot plate at 320 qo to achieve a total stretching of 3 times. This yarn has good appearance and gloss,
The filament is 2d and has a strength of 4. Female No. d, elongation 35%, initial modulus 110 g No. d. When the same process as above was carried out using an oligomer with an average degree of polymerization of 5 and a terminal COO day instead of poly(m-phenylene isophthalamide powder) having a relative viscosity of 3.5, the melting point was 0 instead of 11.

Example 2 Polymer phenylene isophthalamide powder with a relative viscosity of 3.5 was mixed with caprolactam powder in a molar ratio of 1:10.
After mixing at a ratio of , the temperature was raised to 15,000 °C to dissolve.

Then, it was dried at 110 qo, 120 qo, and 130° C. for 6 hours under a reduced pressure of 2 Yanagi Hg. The X-ray diffraction diagram 20 of this product shows 9-00, 11-80, 17-90, 19-80, 2
Clear absorption was observed at 3-30, 24.50 and 28.70. All of these rust bodies had a smooth and dry feel and were easy to handle. The polymer/caprolactam molar ratio determined from the methanol extraction loss of these complexes and the melting point determined from the DSC curve were as follows.

Table 2: Modification of atomization conditions Polymerization prolactam If specific melting point 1 110℃ 1.43 152℃
2 120 1.98
1563 1130 0.3
140No. The threads of No. 2 were extruded through a L-grade yarn nozzle of No. 1 at 17500 at a spinning pressure of 65 x 9/cloth, and the paper yarn was wound at a speed of 20 h/min.

Feed the undrawn yarn into a washing machine with a general length of 3 m at a rate of 2 h/min for 10 minutes.
1 with a take-up roll of 3 h/min while washing at 0℃
．． Three notes were extended. Then, the film was passed through a 17,000 mm drying roller and a 35,020 mm heating ramp to achieve a total stretching of 3 times. 2d filament has a strength of 4. The initial modulus was 100g, the elongation was 30%, and the initial modulus was 100g.

Example 3 The same polymer powder as in Example 2 was mixed with dimethylacetamide'.
After this dissolution, dry spinning was carried out by a conventional method, washed in boiling water, and dried to obtain an undrawn yarn.

The strength of undrawn yarn is 0. Total/d, elongation 230%, density 1.3
There were 4 spots/ground. This undrawn yarn was placed in hot water at 80°C for 30 minutes.
．． It was stretched to 6 times and then dry heat treated to 1.0 times on a 25,000 hot plate. This heat-treated yarn was dispersed in a solvent as shown in Table 3, held at 50 oo for 6 hours, separated in a furnace, and dried under reduced pressure at 2 Hg and 120 C to form a mirror body.

These flanges showed an X-ray diffraction pattern similar to that of Example 2, and were crystalline rust bodies. Table 3 shows the characteristics of these collar bodies.

Table 3 * 6 cp: Six-force Brolacnum Example 4 The same polymer powder as in Example 1 was added to 100 qo at a polymerization ratio of caprolactam/2-pyrrolidone/polymer 10/90/
A solution of No. 20 was prepared and dried at 120q0 under a reduced pressure of 2 Hg for 6 hours.

In the X-ray diffraction diagram of the obtained sample, reflections from the two types of flanges described in Example 1 and Example 2 were observed, and the melting point was 130o.
o and 151°C.

[Brief explanation of the drawing]

It shows each characteristic of the coin body A according to the present invention, and the first
The figure is an X-ray diffraction diagram, Figure 2 is an infrared absorption spectrum, and Figure 3 is an infrared absorption spectrum.
The figure shows the DSC curve, Figures 4 and 5 show dynamic viscoelasticity, and Figure 6 shows the dynamic viscoelasticity.
The figure shows each TGA curve. Outside Europe 2 figures ice 3 figures outside 5 figures outside 4 figures outside 5 figures

Claims (1)

[Claims] 1 Crystalline complex consisting of poly-m phenylene isophthalamide and 2-pyrrolidone or ε-caprolactam, which has a relative viscosity of 1.5 to 5.5 when 1.0 g is dissolved in 100 cc of concentrated sulfuric acid at 25° C. 2 Poly-m phenylene isophthalamide X-ray diffraction angle (2θ) of nylene isophthalamide and 2-pyrrolidone
are 11.0° (m), 17.4° (v.s), 18.4
°(w), 20.2°(w), 21.0°(w), 23
．． 2° (s), 25.0° (s), 26.2° (m),
Crystalline complex 3 of claim 1 exhibiting absorption at 27.4° (m) Polym-phenylene isophthalamide and 2
The X-ray diffraction angles (2θ) produced by contacting with pyrrolidone to form a crystalline complex and then removing 2-pyrrolidone not included in the crystals are 11.0° (m) and 17.4°.
(v.s), 18.4° (w), 20.2° (w), 2
1.0° (w), 23.2° (s), 25.0 (s),
Crystalline complex 4 according to claim 1 or 2, which exhibits absorption at 26.2° (m) and 27.4° (m). The angle (2θ) is 9.0° (s), 11.8° (
w), 17.9° (v.s), 19.8° (m), 23
．． 3° (v.s), 24.5° (m), 28.7° (v.s.
．． Crystalline complex 5 according to claim 1 exhibiting absorption in w) Polym-phenylene isophthalamide and ε-caprolactam are brought into contact to form a crystalline complex, and then ε-caprolactam not included in the crystals is removed. The X-ray diffraction angle (2θ) produced by
), 17.9° (v.s), 19.8° (m), 23.
3° (v.s), 24.5° (m), 28.7° (v.s.
Crystalline complex 6 according to claim 1 or 4, which exhibits absorption in w) A polyester having a relative viscosity of 1.5 to 5.5 when 1.0g is dissolved in 100cc of concentrated sulfuric acid at 25°C. Production of an aromatic polyamide crystalline complex characterized by contacting m-phenylene isophthalamide with 2-pyrrolidone or ε-caprolactam to form a crystalline complex, and then removing 2-pyrrolidone or ε-caprolactam that is not included in the crystals. law