JPH06200413A - Polyamideimide fiber and preparation said fiber - Google Patents

Abstract

PURPOSE: To obtain the subject fiber which has few coloring and good thermochemical behavior and which can be fibrillated by spinning and drawing a soln. of the specified polyamideimide in dimethylalkyleneurea under specified conditions. CONSTITUTION: A soln. of a polymer having an amideimide chain sequence A of formula I, an amide chain sequence B of formula II, an amide chain sequence C of the formula -N-Ar1 -NH-CO-R-CO- and an imide chain sequence D [Ar1 is a trylene and/or metaphenylene divalent aromat. group; Ar2 is a trivalent aromat. group; Ar3 is a tetravalent aromat. group; R is divalent aromat. group; M is alkali (earth) metal; proportions of respective sequences are as follows: the sequence A is 0-100%, the sequence B is 0-5%, the sequence C is 0-<100%, the sequence D is 0-<1000%, preferably 0-80%, the total is 100%] in dimethylalkyleneurea is spun in an aq. bath contg. 30-80 wt.% dimethylalkyleneurea, drawn for twice or more, distilled off the solvent, thereafter dried and drawn for twice (totally 5 times or more) at 250 deg.C or higher.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing heat-stable fibers by spinning a solution of polyamideimide and the fibers thus obtained.

[0002]

According to French Patent 2,079,785, a solution of a polymer in N-methylpyrrolidone is wet spun into an aqueous bath which also contains N-methylpyrrolidone, It is known to produce a polyamideimide-based glossy yarn containing at least 3% of chain sequence starting from an alkali or alkaline earth metal 3,5-dicarboxybenzene sulphonate by subsequent drawing, washing and drying. There is.

However, in addition to the strong yellow coloring,
The yarns also have poor thermodynamic behavior for some applications.

Moreover, according to this patent, it is not possible to obtain polyamideimide fibers having good mechanical properties, even though tolylene diisocyanate and metaphenylene diisocyanate are used as initial isocyanates.

In order to improve the mechanical properties of polyamideimide fibers, according to French Patent No. 2,643,084, polyamideimide fibers are also produced, which are preferably produced from 4,4'-diphenyl ether diisocyanate. It was However, such fibers exhibit low drawability, making it impossible to achieve low linear densities.

In addition, 4,4'-diphenyl ether diisocyanate is a difficult and expensive product to manufacture on a commercial scale.

[0007]

The present invention provides a solution of a polymer in dimethylalkylene urea, where the polymer is:

Amidoimide chain sequence (A) of the following formula:

[0009]

[Chemical 12]

Optionally an amide chain sequence (B) of the formula:

[0011]

[Chemical 13]

Optionally an amide chain sequence (C) of the formula: --NH--Ar ₁ --NH--CO--R--CO--

The imide chain sequence (D) of the following formula:

[0014]

[Chemical 14]

[Wherein Ar ₁ represents a tolylene and / or metaphenylene divalent aromatic group, Ar ₂ represents a trivalent aromatic group, Ar ₃ represents a tetravalent aromatic group, and R
Represents a divalent aromatic group, M represents an alkali metal or an alkaline earth metal,

The chain sequence (A) is present in a proportion of 0 to 100%, preferably 20 to 100%, and the chain sequence (B) is 0 to 5%.
%, The chain sequence (C) is present in the range 0 to <100%, preferably 0 to 80% and the chain sequence (D) is 0.
~ <100%, preferably 0 to 80%,
The total number of chain sequences (A) + (B) + (C) + (D) is 100.
% Equal to]

Dimethyl alkylene urea (DMU) 3
Spinning into an aqueous coagulation medium containing 0-80% by weight, preferably 50-65% by weight,

The filaments obtained are drawn to a draw ratio of at least 2 times, free of residual solvent, dried by any known means and at least at a temperature of 250 ° C., generally at least 300 ° C. or higher, at least It relates to a method for obtaining polyamide-imide-based yarns and fibers by overdrawing to a draw ratio of 2 times, preferably at least 3 times, and drawing at a total draw ratio of at least 5 times, preferably at least 6 times.

The polyamideimide used preferably has an intrinsic viscosity ≧ 0.8 dl / g. The dimethyl alkylene urea used is preferably dimethyl ethylene urea or dimethyl propylene urea.

The yarns and fibers according to the invention comprise polyamides containing the chain sequences of the copolymers A, B, C and D of the above formula and having the same meaning Ar ₁ , Ar ₂ , Ar ₃ , R and M. Concentration of imide in dimethyl alkylene urea 1
It can also be prepared by dry spinning a 5 to 35%, preferably 20 to 30% solution in an evaporating atmosphere that maintains a temperature very close to or above the boiling point of the solvent. At the outlet, the filament is free of residual solvent. For this purpose the filament is
It may be washed with water, optionally under boiling pressure, and dried in a conventional manner, preferably at temperatures above 80 ° C. The filaments may also be heat treated under reduced pressure and / or an inert atmosphere at a temperature ≧ 160 ° C. and drawn at a temperature of 250 ° C. or higher, preferably 300 ° C. or higher, after freeing of residual solvent, preferably in the absence of oxygen. Good.

The total draw ratio applied is at least 5 times,
It is preferably at least 6 times.

The polymer described above was prepared as of December 30, 1968.
French patent application filed on date 1,600,067
Aromatic acid anhydrides, optionally aromatic acid dianhydrides, optionally alkali or alkaline earth metal 3,5-dicarboxybenzene sulfonates, and optionally Is at least one acidic reactant consisting of an aromatic diacid, 2,4-
Reaction of at least one aromatic diisocyanate selected from tolylene or 2,6-tolylene or metaphenylene diisocyanate in an anhydrous polar solvent at substantially stoichiometric proportions and in the absence of a catalyst (a ) Can be obtained by

These polymers also have an acidic reaction consisting of the above-mentioned diisocyanates and aromatic dianhydrides and aromatic diacids, optionally alkali or alkaline earth metal 3,5-dicarboxybenzene sulfonates. It can also be obtained by the reaction (b) with a compound in the absence of an aromatic acid anhydride in a stoichiometric proportion and in the absence of a catalyst.

When reaction (a) is used, the proportions of the various chain sequences are as follows: chain sequence (A): 20-100% chain sequence (B): 0-5% chain sequence (C ): 0 to 80% Chain sequence (D): 0 to 80%.

When reaction (b) is used, the proportion of chain sequences is as follows: chain sequence (A): 0% chain sequence (B): 0-5% chain sequence (C): 0 <100%, preferably 0-80% Chain sequence (D): 0- <100%, preferably 0-80
%. The total number of chain sequences (A) + (B) + (C) + (D) is 100.
%.

The diisocyanates which can be used to obtain the polyamideimide are 2,4- or 2,2-
6-tolylene diisocyanate and metaphenylene diisocyanate or mixtures thereof. In trading, tolylene diisocyanate is 2,4- and 2,6-
It is in the form of a mixture of tolylene (2,4- and 2,6-TDI) isomers. The mixture preferably comprises at least 60% 2,4-TDI.

A small proportion of another aromatic, aliphatic or cycloaliphatic diisocyanate may optionally be added to the above-mentioned diisocyanates in order to improve certain properties of the manufactured articles, for example obtained. Para-phenylene diisocyanate (p
It is expedient to replace up to 30% of m-PDI with -PDI).

The acid anhydride used is preferably trimellitic anhydride, and the aromatic dianhydride is pyromellitic acid, 3,3 ', 4,4'-diphenyltetracarboxylic acid, 2,3,6. , 7-naphthalene tetracarboxylic acid, diphenyl ether 3,3 ′, 4,4′-tetracarboxylic acid, diphenyl sulfone 3,3 ′, 4,4′-tetracarboxylic acid dianhydride, and preferably diphenyl ketone An example is dianhydride of 3,3 ', 4,4'-tetracarboxylic acid. Many of these acid dianhydrides can be used as a mixture, and among the aromatic dianhydrides, terephthalic acid and isophthalic acid are often used, with terephthalic acid being preferred, but like biphenyldicarboxylic acid or naphthalenedicarboxylic acid. Other diacids are also suitable. The trimellitic anhydride used must be pure and, in particular, must not contain more than 5 mol% trimellitic acid.

Alkali or alkaline earth metal 3,5-
The dicarboxybenzene sulfonate is preferably sodium or potassium sulfonate.

The various acids or acid anhydrides and dianhydride compounds are present in the following molar ratios: Aromatic acid anhydride: 0 to 100 relative to the total acidic reactant.
%, Preferably 20 to 100%, aromatic diacid: 0 to <100%, preferably 0 to 80%,
Dicarboxybenzene sulphonate in the proportion of 0 to 5%, Aromatic acid dianhydride: 0 to <1 with respect to the whole acidic reactant
00%. The polymer thus obtained can be spun and in order to obtain a yarn exhibiting good mechanical properties,
At least 0.8 dl / g, preferably at least 0.9
It is preferable to have an intrinsic viscosity of dl / g.

Below these viscosity values, which correspond to insufficient molecular weights, the yarns obtained are difficult to use.

Polyamideimide also has at least 290
C., generally higher than 300.degree. C., which contributes to obtaining yarns with good thermodynamic behavior. Intrinsic viscosity is 2 in a 0.8 mm diameter capillary.
Represents the amount of flow time for a polymer solution at a concentration of 0.5% (weight / volume) in 5% DMEU. η = 4.6 (log t ₁ −log t ₀ ) t ₀ (seconds) is the pure solvent flow time, and t ₁ (seconds) is the solution flow time.

Of the polar organic solvents which can be used, those used are dimethylalkylene ureas, for example dimethylethylene urea or diethylene propylene urea, which have the advantage that the solution of polyamideimide spun is only slightly colored. . In addition, the solution has the trademark Eppr
The viscosity at which the solution is spinnable, measured by viscometers known in the trade under echt Rheomat 15, generally 400-1000 for wet spinning, preferably 500-800 poise, and for dry spinning Must exhibit a viscosity of 1500-3000 poise.

The spinning solution is 10 to 35%, preferably 1
It can have a polymer concentration of 5-25%. The spinning solution may contain various auxiliaries such as colorants, matting agents, stabilizers and the like, intended to modify the appearance or the final properties of the yarn obtained.

The temperature of the spinning solution can be varied within wide limits depending on the viscosity of the solution to be spun. For example, a solution exhibiting a low viscosity can be easily extruded at normal temperatures, but to avoid using excessive die pressure, a solution with a high viscosity is heated while heating at, for example, 120 ° C or higher. Extrusion is preferred.

In the case of wet spinning, the coagulation bath used in the method according to the invention is dimethylalkylene urea (DMA).
U) Aqueous solution containing 30-80% by weight, but DMAU 50% to obtain filaments with better drawability and thus better final properties
It is often convenient to use a bath containing the above.

The speed at which the filaments pass through the coagulation bath is
The solvent concentration and the number of moving distances with the filaments in this bath can be changed within a wide range. The running speed of the filaments in the coagulation bath can easily be chosen, for example 10 to 60 mm / min, although higher speeds can be reached. There is generally no advantage in spinning at low speeds for process profitability reasons. further,
Excessive traveling speed of the filament in the coagulation bath reduces the drawability of the filament in air. The speed at which the filaments pass through the coagulation bath can therefore be selected both considering the profitability of the finished yarn and the desired properties.

The temperature of the coagulation bath can be selected, for example, from 15 to 40 ° C, and is generally from 20 to 30 ° C. The filaments thus obtained are then preferably stretched in air to a draw ratio of at least 2 or more.

After stretching, preferably in air, which is carried out by passing between two sets of rolls, the residual solvent is removed at room temperature by known means, generally by circulating countercurrent mode of water or washing with washing rolls. And removed from the filament.

The yarn obtained by dry spinning is pre-drawn in a spinning chamber and the residual solvent is then removed either by heat treatment at temperatures above 100 ° C. or washing with water, preferably boiling water under pressure. .

In both spinning methods, the washed filaments are then dried by known means, for example in a dryer or on rollers. The temperature of this drying can be varied within wide limits as well as the rate, which is proportionally higher at higher temperatures. It is generally advantageous for the drying to proceed with increasing temperature, for which it is possible, for example, to reach and even exceed 200 ° C.

The filaments from which the solvent and water have been removed can also be subjected to a secondary drawing to improve the mechanical properties of the filaments and achieve finer linear densities below 1 dtex / filament.

The overstretching is carried out by any known means: furnace, plate, roll, at a temperature which can reach at least 250 ° C., preferably at least 300 ° C. and 400 ° C., preferably in the absence of oxygen.

The overstretching is generally carried out at a draw ratio which can reach at least 2 times, preferably at least 3 times, 4 or 5 times, so that the total draw ratio is at least 5 times, preferably at least 6 times.

According to the invention, PAI yarns produced from tolylene diisocyanate or metaphenylene diisocyanate have the unexpected characteristic of exhibiting outstanding drawability and are therefore also French patent 2,079,785.
And No. 2,643,084,
It makes it possible to obtain a finer approach to linear density than polyamideimides produced from 4,4'-diphenylmethane diisocyanate or other diisocyanates such as 4,4'-diphenylether diisocyanate. The PAI yarns of the invention also have the advantage of low pigmentation and, in particular, better thermodynamic behavior, as will be seen from the description that follows the present invention.

The present invention also includes

Amidoimide chain sequence (A) of the formula:

[0048]

[Chemical 15]

Optionally an amide chain sequence (B) of the formula:

[0050]

[Chemical 16]

Optionally an amide chain sequence of the formula:
(C): - NH-Ar 1 -NH-CO-R-CO-

The imide chain sequence (D) of the following formula:

[0053]

[Chemical 17]

[Wherein, Ar ₁ represents a tolylene or metaphenylene divalent aromatic group, Ar ₂ represents a trivalent aromatic group, Ar ₃ represents a tetravalent aromatic group, and R represents Represents a divalent aromatic group, M represents an alkali metal or an alkaline earth metal,

The chain sequence (A) is present in a proportion of 20 to 100%, preferably 50 to 100%, and the chain sequence (B) is
It is present in a proportion of 0 to 5% and the chain sequence (C) is 0 to <10.
Present in a proportion of 0%, preferably 0 to 50%, the chain sequence (D) is 0 to <100%, preferably 20 to 100%
Existing in the ratio of the chain sequence (A) + (B) + (C) +
The sum of (D) is equal to 100%] and has a pronounced thermodynamic behavior and a weak coloration, based on polyamide-imide yarns and fibers.

The yarns and fibers according to the invention preferably have an intrinsic viscosity of 20.8 dl / g, more preferably 0.9 dl / g.
Have.

The thermodynamic behavior is approximately 50 to 400 ° C.
It is evidenced by the retention of the elastic modulus value during the linear increase in temperature while varying the temperature over the range.
The elastic modulus retention is ≧ 40% at 310 ° C., preferably ≧
50%. PA based on tolylene diisocyanate
The yarn produced from I exhibits particularly high thermodynamic behavior.
Yarns based on PAI produced from m-PDI, due to their part, exhibit a very weak initial colouration, which makes it possible to dye in very light shades which are rare for products of this type.

Moreover, the yarns are 100 ° C. at 200 ° C.
Strength retention after 0 hour exposure, at least 75%, preferably at least 80%, and after exposure to 200 ° C for 5000 hours at least 65%, preferably at least 70%.
Has a strength retention rate.

The yarn according to the invention also exhibits excellent drawability which makes it possible to reach very low linear densities below 1 dtex / filament, which is quite unusual in the case of heat-stable yarns. It gives the fabric a very soft texture. Those yarns also have outstanding mechanical properties, breaking strength,
It has elastic modulus and low elongation. The yarns thus combine the texture of the fabric with good mechanical and thermodynamic properties. The yarns can be easily dyed with basic dyes.

The yarns can be used alone or mixed with natural or synthetic yarns for the purpose of improving or altering certain properties. These threads have a wide range of uses,
It finds particular use in workwear and protective clothing.

When the yarns do not contain units (B), they can also form part of many composites, especially compositions for insulating applications.

Finally, those yarns are known for their readily available and relatively low market prices for tolylene diisocyanate and metaphenylene diisocyanate,
They have significant economic advantages because they represent significant industrial advantages. This is particularly significant in comparison with yarns made from polyamideimide produced from 4,4'-diphenyl ether diisocyanate.

In the following examples, the values of M inversion w and M inversion n were determined by gel exclusion chromatography (GP) with NMP at 80 ° C. and 0.1 mol / l lithium bromide.
The molecular weight was measured by C) and expressed in relation to polystyrene calibration. The polydispersity index I is M inversion w / M inversion n
Equivalent to the ratio.

Examples 1 to 4 (TDI): Solutions containing 21% of sulfonated copolyamideimide in dimethylethylene urea were prepared by reaction of the following components in the absence of a catalyst. DMEU ... 257.1 g ... 244 ml Tolylene diisocyanate ... 87 g ... 0.5 mol Trimellitic anhydride 76.8 g ... 0.4 mol ... (8
0 mol%) terephthalic acid (TA) 13.28 g ... 0.08 mol ...
(16 mol%) Sodium 3,5-dicarboxybenzenesulfonate 5.36 g ... 0.02 mol ... (4 mol%) DMEU diluent 263.7 g ... 250 ml Molecular weight M inversion: n50,020 Other dispersibility I: 1 0.78 Intrinsic viscosity 0.97 dl / g A 21% strength solution was obtained having a viscosity of 603 poise measured with an Epprecht Rheomat 15 viscometer. Container D + E at 25 ° C.

The solution maintained at a temperature of 70.degree.
27 through a die containing 62 orifices of 06 mm
Extrusion into a DMEU / water coagulation bath containing 62% by weight DMEU and 38% by weight water maintained at 0 ° C., the distance the filaments in this bath traveled was approximately 1 meter. Upon leaving the coagulation bath, the filaments were drawn by the first set of rollers and drawn in air between the first and second set of rollers to a draw ratio of 2X. The filament is then washed countercurrently with water in a wash tank,
It was dried in an oven maintained at approximately 150 ° C and then overstretched in an oven maintained at approximately 350 ° C.

Several overstretch ratios were used. The characteristics of the yarn are shown in Table 1 below.

[0067]

[Table 1]

Thermal behavior: Toughness retention is 100 at 200 ° C.
It is 80% after 0 hour exposure and 70% after 5000 hours at 200 ° C.

A yarn obtained according to French Patent No. 2,643,084 consisting of a polyamide-imide produced from a monomer similar to the above, except that the toluene diisocyanate was replaced by 4,4'-diphenylmethane diisocyanate. The toughness retention rate after exposure at 200 ° C. for 1000 hours was 38%.

Thermodynamic behavior: Retention of modulus as a function of temperature: yarn retains 50% of its modulus at 310 ° C., based on 4,4′-diphenylmethane diisocyanate, French patent 2,643. The yarn prepared by No. 0884 has a modulus of 22.
Only 5% was retained.

Example 5 Polyamideimide was prepared as shown in Example 1, substituting Tphenyl with metaphenylene diisocyanate in the same molar ratio.

The obtained PAI has a molecular weight M inversion n: 36,
560 and polydispersity index: 2.05, 0.86
It has an intrinsic viscosity of dl / g. Epprecht Rhe
The viscosity of the solution, measured using an omat viscometer, is 5
66 poise.

The polyamideimide solution having a concentration of 21% thus obtained was spun, treated as shown in Example 1 and air-stretched to a draw ratio of 2.31 and then 2.3. Overstretched to a stretch ratio of 5 and a total stretch ratio of 5.
29 times.

The yarn obtained has the following characteristics: : Linear density (dtex): 2.3 fracture strength: 26 g / tex fracture elongation: 18% retention of toughness after heat aging for 1000 hours at 250 ° C .: 7
5% Thermodynamic behavior: Elastic modulus retention at 310 ° C: 40%

Examples 6-8: A kermel based on TDI and 40% TAA solution containing 21% sulfonated copolyamideimide in dimethylethylene urea was prepared by reaction of the following components. DMEU ... 251.3 g ... 238 ml Tolylene diisocyanate 87 g ... 0.5 mol Trimellitic anhydride 53.76 g ... 0.28 mol (5
6 mol%) terephthalic acid 33.20 g ... 0.20 mol (40 mol%) 3,5-carboxybenzenesulfonic acid sodium salt
5.36 g ... 0.02 mol (4 mol%) DMEU diluent 257.40 g ... 244 ml Molecular weight M inversion n: 40,560 Polydispersity I: 1.98 Intrinsic viscosity: 0.95 dl / g

A solution having a viscosity of 606 poise measured with an Epprecht Rheomat 15 viscometer was obtained. Container D + E at 25 ° C.

The solution maintained at a temperature of 70 ° C. had a diameter of 0.
27 ° C through a die containing 62 06 mm orifices
Was extruded into a DMEU / water coagulation bath containing 62% by weight of DMEU and 38% by weight of water, the distance traveled by the filaments in this bath was approximately 1 meter. Upon leaving the coagulation bath, the filaments were taken up by the first set of rollers and drawn in air between the first and second set of rollers to a draw ratio of 2X. The filament is then washed countercurrently with water in a wash tank, approximately 1
It was dried in an oven maintained at 50 ° C and then overstretched in an oven maintained at an approximate temperature of 350 ° C.

Several overstretch ratios were used. The characteristics of the yarn are shown in Table 2 below. :

[0079]

[Table 2]

Example 9: A solution containing 21% of sulfonated copolyamide in dimethyl propylene urea was prepared by reaction of the following components in the absence of catalyst. : Dimethylpropyleneurea (DMPU) ... 279.8 g
(D = 1.064) = 263.0 ml Trimellitic anhydride .... 61.44
g (0.32 mol) terephthalic acid ......... 13.28
g (0.08 mol) 1,3-phenylene diisocyanate ... 64 g
(0.4 mol) DMPU diluent ......... 109.6
g 103 ml

A 21% strength solution in DMPU was obtained having a viscosity of 810 poise, measured as shown in Example 1. The PAI thus obtained had a molecular weight Mn = 3.
7,840, polydispersity 2.34 and intrinsic viscosity 0.89
dl / g.

The solution thus obtained was spun as described in Example 1, the filaments obtained were drawn to a draw ratio of 2 times, washed, dried and then brought to 335 ° C. to a draw ratio of 3 times. Overstretched in a maintained furnace.

The obtained filament has the following characteristics.

[0084]

[Table 3]

Thermodynamic Behavior-Elastic Modulus Retention: 310 ° C
In: 43% retention of initial modulus

Examples 10-12 A solution containing 21% of sulfonated copolyamideimide in dimethylethylene urea was prepared by reacting the following components in the absence of a catalyst. : DMEU ......... 257.1 g ... 244 ml Tolylene diisocyanate 87 g ... 0.5 mol Trimellitic anhydride 76.8 g ... 0.4 mol (80
Mol%) terephthalic acid (TA) 13.28 g ... 0.08 mol (16 mol%) 3,5-dicarboxybenzene sodium sulfonate 5.36 g ... 0.02 mol (4 mol%) DMEU diluent 263.7 g 250 ml Molecular weight M inversion n: 60,100 Polydispersity I: 2 Intrinsic viscosity: 1 dl / g

A concentration of 21 with a viscosity of 603 poise measured with an Epprecht Rheomat 15 viscometer.
% Solution was obtained. Container D + E at 25 ° C. DMEU used for polycondensation and spinning in these examples
Was recycled in advance after purification, especially by distillation.

The solution maintained at a temperature of 70 ° C. had a diameter of 0.
2 through die with 065 mm 62 orifices
Extruded into a DMEU / water coagulation bath containing 62 wt% DMEU and 38 wt% water maintained at 8 ° C,
The distance traveled by the filaments in this bath was approximately 1 meter. Upon leaving the coagulation bath, the filaments were taken up by the first set of rollers and drawn in air between the first and second set of rollers to a draw ratio of 2.5. The filaments were then washed countercurrently with water in a wash tank, dried in an oven maintained at approximately 120 ° C and then overstretched in an oven maintained at approximately 370 ° C.

Several overstretch ratios were used. The characteristics of the yarn are shown in Table 3 below.

[0090]

[Table 4]

Thermodynamic behavior: Retention of elastic modulus as a function of temperature: The yarn retained 50% of its modulus at 310 ° C.

Examples 13 and 14: Solutions containing 21% of copolyamideimide in dimethylethylene urea were prepared by reaction of the following components in the absence of catalyst. : Tolylene diisocyanate ... 0.5 mol Trimellitic anhydride ... 0.4 mol (80 mol%) Terephthalic acid (TA) ... 0.10 mol (20 mol%) Intrinsic viscosity ... 0.97 dl / g

The solution, maintained at a temperature of 70 ° C., was passed through a die containing 62 orifices of 0.065 mm diameter and maintained at 28 ° C., containing 62% by weight of DMEU and 38% by weight of water. It was extruded into the bath, but the distance that the filament moves in this bath is approximately 1
It was a meter. Upon leaving the coagulation bath, the filaments were taken up by the first set of rollers and drawn in the air between the first and second set of rollers to a draw ratio of 2.2. The filaments were then washed countercurrently with water in a wash tank, dried in an oven maintained at approximately 120 ° C and overdrawn in an oven maintained at approximately 350 ° C.

Several overstretch ratios were used. The characteristics of the yarn are shown in Table 5 below.

[0095]

[Table 5]

Aging test. Thermodynamic behavior: Retention of elastic modulus as a function of temperature The yarn retained 50% of its modulus at 310 ° C.

Examples 15 to 17 25% copolyamideimide in dimethylethylene urea
Was prepared by reacting the following components in the absence of a catalyst. Dimethyl ethylene urea (DMEU): 269.3 g (d
= 1.056) 255 ml Benzophenone anhydrous tetracarboxylic acid: 80.5 g
(0.25 mol) (50 mol%) Terephthalic acid: 41.5 g (0.25 mol) (50
Mol%) Tolylene diisocyanate: 87 g (0.50 mol) DMEU diluent 185.7 g (176 ml)

A 21% strength solution in DMEU having a viscosity of 580 poise measured as indicated in Example 1 was obtained. The PAI thus obtained has a molecular weight M inversion n = 3.
6250 and polydispersity 2.10. Intrinsic viscosity: 0.85dl / g

The resulting solution was spun as shown in Example 1 and the resulting filament was drawn to a draw ratio of 2.2, washed, dried and then oven maintained at 345 ° C. Overstretched in.

Several overstretch ratios were applied. The characteristics of the yarn are shown in Table 6 below.

[0101]

[Table 6]

Claims (19)

[Claims] 1. The following steps: a) A solution of the polymer in dimethyl alkylene urea (DMU), where the polymer is: an amide imide chain sequence (A) of the formula: An amide chain sequence (B) of the following formula: Amide chain sequence (C) of the following formula: -NH-Ar ₁ -NH-CO-R-CO- Imido chain sequence (D) of the following formula: [Wherein, Ar ₁ represents a tolylene and / or metaphenylene divalent aromatic group, Ar ₂ represents a trivalent aromatic group, Ar ₃ represents a tetravalent aromatic group, and R represents 2 Represents a valent aromatic group, M represents an alkali metal or an alkaline earth metal, the chain sequence (A) is present in a proportion of 0 to 100%, the chain sequence (B) is a proportion of 0 to 5% And the chain sequence (C) is present in a proportion of 0 to <100%, the chain sequence (D) is 0 to <100%, preferably 0 to 80
%, And the total number of chain sequences (A) + (B) + (C) + (D) is 100.
% Dimethyl alkylene urea (D
MAU) spinning into an aqueous coagulation medium containing 30-80% by weight of water and 20-70% by weight of water, b) stretching the resulting filament at a draw ratio of at least 2 times, and c) residual solvent into filaments. Removing the filaments by any known means, and d) overdrawing the filaments at a temperature of at least 250 ° C. to a draw ratio of at least 2 times, resulting in a total draw ratio of 5 times. A method for producing a polyamide-imide based yarn and fiber with improved thermodynamic behavior. 2. The solvent is removed by washing.
The method described in. 3. The method according to claim 1, wherein the coagulation bath contains 50 to 65% by weight of solvent. 4. The method of claim 1, wherein the overstretching is carried out at a draw ratio of at least 3 times, resulting in a total draw ratio of 6 times. 5. The method according to claim 1, wherein the overstretching is carried out at least at a temperature of 300 ° C. in the absence of oxygen. 6. The following steps: a) A solution of the polymer in dimethyl alkylene urea (DMU), where the polymer is: an amide imide chain sequence (A) of the formula: An amide chain sequence (B) of the following formula: Amide chain sequences of the following formula _{(C): NH-Ar 1} -NH-CO-R-CO- following formula imide chain sequences (D): embedded image [In the formula, Ar ₁ represents a tolylene or metaphenylene divalent aromatic group, Ar ₂ represents a trivalent aromatic group, Ar ₃ represents a tetravalent aromatic group, and R represents a divalent aromatic group. Represents a group group, M represents an alkali metal or an alkaline earth metal, the chain sequence (A) is present in a proportion of 20 to 100%, the chain sequence (B) is present in a proportion of 0 to 5% The chain sequence (C) is present in a ratio of 0 to <100%, and the chain sequence (D) is 0 to <100%, preferably 0 to 80%.
%, And the total number of chain sequences (A) + (B) + (C) + (D) is 100.
%] In a vaporizing atmosphere maintained at a temperature very close to or above the boiling point of the solvent to remove residual solvent from the filament, which is then heated at a temperature above 250 ° C. Stretching, so that the total stretch ratio is at least 5 times,
Method for obtaining polyamide-imide based yarns and fibers with improved thermodynamic behavior. 7. The method of claim 6, wherein residual solvent is removed from the filaments by heat treatment at a temperature ≧ 160 ° C. 8. Residual solvent is removed from the filaments by washing with boiling water and dried in the usual way.
The method of claim 6. 9. The method according to claim 6, wherein the stretching is carried out at a temperature of at least 300 ° C. 10. The polyamideimide has an intrinsic viscosity of ≧ 0.
8 dl / g, preferably ≧ 0.9 dl / g.
The method described in. 11. The following features: Amidoimide chain sequence (A) of the formula: An amide chain sequence (B) of the following formula: Amide chain sequence (C) of the following formula: NH-Ar ₁ -NH-CO-R-CO- Imido chain sequence (D) of the following formula: [Wherein, Ar ₁ represents a tolylene and / or metaphenylene divalent aromatic group, Ar ₂ represents a trivalent aromatic group, Ar ₃ represents a tetravalent aromatic group, and R represents 2 Represents a valent aromatic group, M represents an alkali metal or alkaline earth metal, the chain sequence (A) is present in a proportion of 20 to 100%, the chain sequence (B) is a proportion of 0 to 5% , The chain sequence (C) is present in a ratio of 0 to <100%, the chain sequence (D) is present in a ratio of 0 to <100%, the chain sequence (A) + (B) + The total of (C) + (D) is 100
%, And they are at least 4 at 310 ° C.
Polyamideimide-based thermostable yarns and fibers characterized by having a modulus retention of 0%. 12. The polyamideimide has an intrinsic viscosity of ≧ 0.8.
dl / g, preferably ≧ 0.9 dl / g.
The yarn and fiber according to 1. And how to obtain the fiber. 13. A chain sequence (A) at a rate of 50 to 100%, a chain sequence (B) at a rate of 0 to 3%, a chain sequence (C) at a rate of 0 to 50%, and a chain sequence. (D) is 0-80%
The yarn and fiber of claim 11 present in a proportion of. 14. Ar ₃ is a group of the following formula: 12. The yarn and fiber of claim 11, which is 15. R is a group of the formula 12. The yarn and fiber of claim 11, which is 16. The method according to claim 11, wherein M is an alkali metal.
Yarns and fibers according to. 17. The yarn and fiber of claim 11 having a modulus retention of at least 50%. 18. The yarn and fiber according to claim 11, wherein they have a linear density ≦ 1 dtex. 19. A heat stable article comprising the yarns and fibers of claim 11.