JPS6029738B2 - Aromatic polyamide crystalline complex - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to melt-formable aromatic polyamide crystalline complexes.

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 studies on a method for molding aromatic polyamide polymers at low temperatures without requiring a large amount of solvent, and as a result, have achieved the above object with the rust body specified in the present invention. The scales were discovered.

That is, the gist of the present invention is that 25 qo concentrated sulfuric acid 1
1 in 00cc. Relative viscosity when dissolved is 1.5~
It is an aromatic polyamide crystalline complex consisting of poly(m) phenylene isophthalamide and hexamethylphosphoramide, which is 5.5, and consisting of the following repeating units.

The crystalline complex of the present invention is a free-flowing substance in which aromatic polym-phenylene isophthalamide and hexamethylphosphoramide coexist within the crystal lattice to form a novel crystalline chain. .

Such crystalline bodies are completely new chemical substances that have not been previously known to the world.

The crystalline collar body of the present invention has at least 75 repeating structural units.
An aromatic polyamide polymer having a molar percentage of phenylene isophthalamide is brought into contact with hexamethylphosphoramide to form a crystalline body, and then hexamethylphosphoramide not included in the crystals is removed. Manufactured by

The manufacturing method will be described more specifically as follows. Hexamethylphosphoramide (hereinafter abbreviated as HMPA) is preferably used alone, but a small amount of other solvent may be used in combination.

The form of the aromatic polyamide polymer (hereinafter sometimes abbreviated as PmIA) to be used is not particularly limited, and may be a powder state, an unoriented or oriented fibrous material woven and shaped by a conventional method,
Either a film-like material or a 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 2500).
(measured in female concentration, the same applies hereafter). Industrially, it is preferable to form a crystalline mirror in a short period of 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 at least 350 qo for at least 30 minutes. It is desirable that the

Such an aromatic polyamide polymer and HMPA are brought into contact with each other for a suitable period of time, preferably 3 minutes to 6 hours, more preferably 5 minutes to 3 hours, to form a crystalline body.

Any contact method may be used, but it is preferable to contact the polymer with H.
This method is based on the method of absorbing MPA or dissolving the polymer in HMPA. At this time, the contact ratio between the polymer and the HM circle A is such that HMPA is preferably present in a molar ratio of 1 or more in order to obtain a uniform crystalline coin body. On the other hand, a large amount of H
Since the use of MPA is industrially disadvantageous in subsequent operations, it is preferable to use an amount that satisfies dissolution and absorption rates, that is, a ratio of about 5 times the amount of MPA per polymer. The temperature at which the polymer and HMPA are brought into contact is not particularly limited;
It is desirable to do this within the range of 30oo. Next, in order to remove excess HMPA not contained in the crystalline mirror, centrifugal desolvation, furnace filtration, distillation, or drying treatment by concentrating vessel is performed.
Since the crystalline complex produced has a low melting point, the drying temperature is lower than the melting point, that is, 130 qo or less, preferably 110°C.
It is preferable to adopt the following temperature conditions. The characteristic values of the crystalline rust body of the present invention are, for example, polyphenylene isophthalamide powder with a relative viscosity of 3.2 is mixed in HMPA with a ratio of HMPA/polymer 10/1 (weight ratio) for 6 years. The following is a case where a crystalline complex is obtained by soaking the mixture in an oven, vacuum drying at 60 oo for 24 hours to remove HMPA not included in the crystals. (The crystalline rust body thus obtained is hereinafter referred to as complex A.) The X-ray diffraction pattern of fin body A is shown in Table 1.

Table 1 Based on these results, we analyzed the crystal structure and found that mirror A belongs to the monoclinic system and consists of the following unit cell.

a=10.48A b=16.94 people C=11.30A 8=131.30 The theoretical density is 1.31 honey.

The actual value was 1.2 places/place when measured with 3000 in Decalin. 1.20 to 1.2 depending on the formation conditions of bell bodies
Spotty/evenly fluctuating. The theoretical density of untreated poly(m-phenylene-sophthalamide) fiber is 1.47g/, and the actual density is 1.47g/. This is the land that goes all the way back to my father. Examining the infrared absorption spectra of polym-phenylenesophthalamide, Complex A, and HMPA, the N-day stretching vibration of the polymer is 3300 skin-1,
The P=○ stretching vibration of HMPA appears at 1220 k-1, whereas the N-day stretching vibration of complex A appears at 3200 k-1 and is shifted to a lower wave number of 100 k-1.

Also, P = ○ stretching vibration appears in 1200 skin-1 and 20 arc-
1, and it is considered that a P○...HN bond is formed.

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

An endothermic peak was observed at 123°C. The melting point varies from 111 to 129 depending on the degree of polymerization of the polymer used in contact with HMPA.
Changes up to q0. This is much lower than the melting point (420°C) of polym-phenylene sophthalamide polymer;
This shows that the crystalline complex of the present invention is completely new. When examining the mechanical viscoelastic behavior of the collar body A, it is found that 110oo
There is a sudden rise in tan6 after passing , and correspondingly, E' drops rapidly and seriously.

Measurement becomes impossible at temperatures above 132°C, and it is thought that flow occurs at this temperature range.

This phenomenon shows the possibility of using the melt-fused paper yarn of the crystalline collar body of the present invention. When key body A was desolvented by extraction with boiling water, the molar ratio of polym-phenylene isophthalamide to HMPA was 1:1.88 (=weight ratio 1:1.42).

This value also changes depending on the conditions for forming the collar body, and the molar ratio of polymer to solvent is 0.4 to 1. You can get the general idea. For thermogravimetric analysis, a DSC curve was measured at a heating rate of 2.5 q0/min in air.
230 qo is the boiling point of HMPA, and the weight loss above 400 qo is thought to be due to decomposition of the polymer, so approximately 55% by weight of HMPA is contained in the rust body, which is the same as the value measured by boiling water extraction above. They match well.

The crystallization index of Suzutai A was calculated from the X-ray diffraction diagram as follows: o Toru = Hai = Tsuba = o. 77 This varies from 0.63 to 0.77 depending on the formation conditions of the bell body.

The crystal size was calculated as follows using the reflection spread on the meridian of 28:15.1o.

k-type D = No millet ^:1.5418△ k:0.89 0:28=15-1 6: Half price after silicon correction From this, the crystal size was 69Δ.

This value also changes from 66 to 72A depending on the conditions for forming the flange body.
From the above results, it is considered that the crystalline complex A obtained in the present invention has a chemical structural formula with the above-mentioned line return. 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, aromatic polyamide polymers prepared by using oriented fibers to form crystalline rust bodies are useful as they exhibit excellent performance as binders for nonwoven fabrics. This makes it possible to provide these products at an extremely low cost compared to the conventional method of using po-IJm phenylene isophthalamide itself. In the aromatic polyamide polymer used in the present invention, at least 75 mol% of the repeating units are obtained by reacting a phenylene amine with an isophthalic acid halide such as isophthalic acid chloride by solution polymerization or interfacial polymerization. Comprised of phenylenesophthalamide.

If the copolymerization component exceeds 25 mol %, the crystallinity of the crystalline body produced will be markedly reduced, making it unfavorable for handling.

The components to be copolymerized as necessary include p-phenylene diamine, benzidine, 44 diaminodiphenyl ether, 44' diaminodiphenyl sulfone, etc. as the amine component, and terephthalic acid chloride, 1.4 naphthalene dicarbonate as the brewing component. Sour. dicarboxylic acid halides such as Ride, 2.6 naphthalene dicarboxylic acid chloride, diphenyl sulfone 44 dicarboxylic acid chloride, and diphenyl ether 44 dicarboxylic acid chloride. 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 Relative viscosity is 3
．． HM polym-phenylene isophthalamide powder
Soaked in PA at a ratio of HMPA/polymer = 3/1 (weight ratio) for 50do for 2 hours, and after furnace separation, 60q○, 2
Vacuum drying of the 2nd side Hg was performed for 5 hours at the leg Hg.

The X-ray diffraction diagram of this product shows 28=14.00, 15.1
0, 19.10 and 22. A strong and sharp absorption was observed at the end. These are different from the absorption of polym-phenylene sophthalamide crystals. Boiling water extraction loss is 56wt%
This is the amount of HMPA contained in the sample, but even though it contained such a large amount of solvent, it gave a dry and smooth feel and was easy to handle.

The melting point of the discussion fee from the DSC curve was 116°C. The powder sample was well incorporated into the screw and had good spinnability.

The strength of the yarn after extrusion with a syringe, withdrawal, and desolvation in boiling water was 2.1 g nod.

Example 2 The same powder as in Example 1 was dissolved in dimethylacetamide, then dry spun using a conventional method, washed in boiling water, and dried to obtain an undrawn yarn.

This drawn yarn has a strength of 0. Total/d, elongation 230%, density 1
．． It was 34 tsunagi/ground. 3. Place this in 80oo hot water.
Stretched 6 times and placed on a hot plate under the conditions shown in Table 1. It was heat-treated in parallel. Next, the fibers after the bonding treatment were separated into HM Yen A,
The mixture was dried by centrifugation at 80:00 for 2 hours to remove the solvent. Although these samples retained their fibrous form, similar to Example 1, they exhibited absorption characteristic of crystalline keys. These properties are shown in Table 2. 2. Complex fibers formed from undrawn yarns are brittle and can be powdered.

In the complex fiber obtained from the heat-treated yarn, the distribution of complex crystals was observed.

These fibrous complexes are suitable as starting materials for nonwoven fabrics and plate-shaped molded products.

Example 3 A film sample obtained from polym-phenylene isophthalamide with a relative viscosity of 3.2 by a conventional method was stretched 4 times in clean water, and an oriented film was placed in 6500 HMPA at a ratio of HMPA/polymer = 10/1 (weight ratio ) for 60 hours, then 60oo
Vacuum drying was carried out at 3 degrees Hg for 2 hours.

The obtained sample was subjected to X-ray diffraction, and a camera radius of 35 ribs and a cylindrical photograph were taken during full rotation. Many absorptions other than those shown in Table 1 were observed. 28=14o is on the 1st layer line, 2
0=15.1o is on the meridian on the 2nd layer line 28=26.
50 was the reflection on the 3-layer line.

The melting point was 12,500 from the DSC curve, and the amount extracted with boiling water was a polymer/HMPA molar ratio of 1/1.76. Density is 1.2
The crystal size was 67A and lt/lc=0.67. Example 4 An oligomer with an average degree of polymerization of 5 and a terminal COO day was prepared at 65°C for 1
0 hours, immersed in HM circle A at a ratio of HM circle A/polymer = 10/1 (weight ratio), and heated at 6000 for 2 hours after furnace separation.
Vacuum drying was carried out under Hg.

The X-ray diffraction pattern was the same as in Example 1, and the melting point from the DSC curve was 11ro. When extracted with boiling water, the polymer/
HMPA = molar ratio 1/1. It was spotted and the density was 1.2 crabs/me. Example 5 A polymer powder with a relative viscosity of 3.5 obtained by low-temperature solution polymerization of m-phenylenediamine and isophthalic acid chloride/terephthalic acid chloride 90/10 (molar ratio) was subjected to HMP.
The mixture was dissolved in A at 6,000 ℃, then concentrated under reduced pressure at 40 qo, and dried for 1 hour under a reduced pressure of 2 skin Hg at 0:40 qo to obtain a smooth powder.

It was confirmed from the X-ray diffraction diagram that crystals were formed. The boiling water extraction loss of this product is 50.5M%,
The melting point was determined to be 115°C from the DSC curve.

When melted at 130 oo, a molten metal was obtained, which had excellent moldability.

Claims (1)

[Claims] 1 Consists of polym-phenylene isophthalamide and hexamethylphosphoramide, which has a relative viscosity of 1.5 to 5.5 when 1.0g is dissolved in 100cc of concentrated sulfuric acid at 25°C, and consists of the following repeating units: Aromatic polyamide crystalline complex▲Mathematical formulas, chemical formulas, tables, etc. are available▼