JPH07189030A - Aromatic polyester amide fiber improved in abrasion resistance - Google Patents

Abstract

PURPOSE:To produce a high-tenacity and high-modulus polyester amide fiber having anisotropic melting properties, excellent in abrasion resistance and suitable for a tension member. CONSTITUTION:An aromatic polyester amide fiber containing >=90wt.% segments composed of repeating units A (formula I), B (formula II), C (formula III), D (formula IV) and E (formula V) in a molar ratio of A:B:C:D:E =100:1-20:5-100:2-80:2-20 is melt-spun to obtain the objective aromatic polyester amide fiber having anisotropic melting properties and >=20g/d strength, >=850g/d modulus and excellent in abrasion resistance and cut resistance. These properties are most remarkably exhibited in the case of 40 to 80mol% repeating unit A and n=2 in the repeating unit D.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to melt anisotropic polyesteramide fibers having high tenacity and high elastic modulus and improved abrasion resistance.

[0002]

2. Description of the Related Art As a high-strength and high-modulus fiber, fused liquid crystalline aromatic polyester fiber, fused anisotropic aromatic polyesteramide fiber, and the like are disclosed in JP-A-61-174408 and JP-A-57.
-177019, for example.

[0003]

In the fields of application such as tension members, fibers having excellent strength, elastic modulus, cut resistance, abrasion resistance and the like are required, but fibers having satisfactory performance are not available. It wasn't done. Although the fused anisotropic aromatic polyester fiber exhibits high strength, it is insufficient in terms of elastic modulus, and when used as a tension member or the like, it expands when a large load is applied, which causes various inconveniences. Becomes Further, although the conventional fused liquid crystalline aromatic polyesteramide fiber shows a high elastic modulus to some extent, it has insufficient strength and cut resistance, and there is a big problem particularly in wear resistance. The present invention, in view of the above-mentioned drawbacks of the prior art, as a result of intensive studies, found a high-strength, high-modulus aromatic polyesteramide fiber having excellent wear resistance, fibril resistance, and cut resistance. It is a thing.

[0004]

The present invention includes the following [A] to
The proportion of the repeating structural unit of [E] is 90 mol% or more, and [A]: [B]: [C]: [D]: [E] = 1
Melt anisotropic polyester comprising an aromatic polyesteramide having a molar ratio of 00: 1 to 20: 5 to 100: 2 to 80: 2 to 20 and having a strength of 20 g / d or more and an elastic modulus of 850 g / d or more. By providing amide fibers,
This problem is solved.

[0005]

[Chemical 1]

From the standpoints of spinnability, processability, strength, elastic modulus, etc., it is necessary to use an aromatic polyesteramide having the above-mentioned structural units [A] to [E] in a specific ratio. Even if a polymer other than the aromatic polyester amide used in the present invention is used, a fiber excellent in spinnability, strength, elastic modulus, abrasion resistance, cut resistance, non-water absorption, etc. as in the present invention cannot be obtained. . Preferably, [A]: [B]: [C]:
The molar ratio of [D]: [E] is 100: 3 to 10:15 to 6
A melt anisotropic aromatic polyesteramide having a ratio of 0:10 to 45: 5 to 15 is used. Most notably,
Among the repeating constitutional units shown in Chemical formula 1, the constitutional unit [A] is 40 to 80
It is an aromatic polyesteramide having a mol% and a structural unit [D] of n = 2. Other aromatic, alicyclic, or aliphatic diols, dicarboxylic acids, hydroxycarboxylic acids, diamines, hydroxyamines and the like may be contained to the extent that the effects of the present invention are not impaired. Specific examples include isophthalic acid, naphthylene dicarboxylic acid, dioxynaphthalene, and benzenediamine. However, if the amount of these monomers exceeds 10 mol%, the effect of the present invention is impaired. The melt anisotropy referred to in the present invention means to exhibit optical anisotropy in the melt phase. For example, the sample can be certified by placing it on a hot stage, heating it up in a nitrogen atmosphere, and observing the transmitted light of the sample.

The aromatic polyesteramide fiber of the present invention has a strength of 20 g / d or more and an elastic modulus of 850 g / d or more, but has a strength of 22 g / d or more, an elastic modulus of 900 g / d or more, and an abrasion resistance of 20,000 times. The above is more preferable, and the cut resistance is preferably 4 kg or more. The abrasion resistance referred to in the present invention is a value determined by the following interfiber abrasion test. That is, a 1500d sample yarn was twisted to 80t / m, and twisted three times to the reversing rotor and the pulley at the other end, and
It is the number of times until the yarn is cut when the yarn is set in the shape of, and a load of 2 kg is applied to the pulley, and the yarn is twisted back and forth at a speed of 40 reciprocations / min by the anti-rotation body. In addition, the cut resistance is determined by fixing the blade of the cutter knife to an Instron type universal testing machine, rotating the yarn with a yarn length of 30 cm around the blade to perform a tensile test, and measuring the strength of the yarn when it is cut. It is the indicated value.

The melt anisotropic polymer has a decomposition initiation temperature (T
The temperature difference between d) and the melting point (Tm) is preferably 40 ° C. or more. Melt spinning is performed by heating the spinning machine at a temperature higher than the melting point, but since the temperature changes within a certain range with respect to the set temperature, the temperature may be higher than the set temperature. If the temperature difference between the decomposition start temperature (Td) and the melting point (Tm) of the melt anisotropic polymer is less than 40 ° C, the temperature of the polymer exceeds the melting point and reaches the decomposition temperature while the polymer stays in the pipe. -Is decomposed, and a screw, that is, a broken yarn is generated near the spinning nozzle. Even when no screw is generated, bubbles considered to be decomposed gas are generated in the fiber, and the mechanical performance is deteriorated. The decomposition start temperature (Td) described here is a temperature reduction start temperature in a TG curve (thermogravimetric curve), and the Tm described here is a differential scanning calorie (DSC: TA manufactured by mettler, TA, for example).
3000) is the peak temperature of the main endothermic peak.
(JISK7121)

The aromatic polyester amide fiber of the present invention can be obtained by melt spinning by a conventional method. The spinning temperature is 10 ° C. or more higher than the melting point of the aromatic polyester amide (and the temperature range in which a molten liquid crystal is formed). It is preferable to spin at a shear rate of 10 ³ sec ⁻¹ or more and a spinning draft of 20 or more. By spinning at such a shear rate and a spinning draft, the orientation of molecules proceeds and excellent performance such as strength can be obtained. Shear rate (γ) is nozzle radius r (cm), polymer per single hole and discharge amount Q
When it is (cm ³ / sec), it is calculated by r = 4Q / πr ³ . When the nozzle cross section is not a circle, the radius of a circle having the same area as the cross-sectional area is r.

In order to obtain the fiber of the present invention, it is necessary to heat-treat and / or draw-heat treat the spun yarn in order to improve strength, elastic modulus, abrasion resistance and cut resistance. The heat treatment is performed by increasing the strength to less than 50% in an inert atmosphere and then in an active atmosphere. When the strength is increased by 50% or more in the active atmosphere, the oxidation resistance and the cross-linking reaction do not sufficiently proceed even if the heat treatment is subsequently performed in the active atmosphere, resulting in low wear resistance. Further, if the heat treatment is performed only in an active atmosphere, the strength and elastic modulus are not sufficiently increased, and the fiber of the present invention cannot be obtained. However, even an unheat-treated yarn can be used according to the application and purpose.
Incidentally, under an inert atmosphere, nitrogen, in an inert gas such as argon or under reduced pressure, the active gas such as oxygen is 0.
It means less than 1% by volume. The term "under an active atmosphere" means an atmosphere containing 1% or more of an active gas such as oxygen, preferably an oxygen-containing gas of 10% or more, and it is preferable to use air in terms of cost. When water is present, the hydrolysis reaction proceeds concurrently, so a dry gas having a dew point of -20 ° C or lower, preferably -40 ° C or lower is used.

A preferable temperature condition for the heat treatment is a pattern in which the temperature is gradually increased from Tm-40 ° C in the temperature range of Tm-60 ° C to Tm + 20 ° C with respect to the melting point Tm of the polymer.
Further, since the melting point gradually rises due to the heat treatment, it is possible to perform the heat treatment at a temperature higher than the initial melting point.
When heat is supplied by a medium such as gas, a heating plate,
There are a method of utilizing radiation from an infrared heater, a method of contacting with a heat roller, a plate, etc., an internal heating method using high frequency, etc. It is done under tension. The shape of the treatment may be a maze, a tease, a tow (for example, placed on a wire net), or
It is carried out by continuous treatment of rollers, and the filament may be in the form of filament or cut fiber.

The aromatic polyesteramide of the present invention includes
Polyethylene terephthalate, polyolefin, polycarbonate, polyarylate, polyamide, polyphenylene sulfide, polyether ester ketone, may contain thermoplastic polymers such as fluorine resin, titanium oxide, kaolin, Inorganic substances such as silica and barium oxide, carbon black, colorants such as dyes and pigments, antioxidants, ultraviolet absorbers and light stabilizers may be added.

The fiber of the present invention can be used in various industrial fields, and specific examples are as follows. 1. Materials used in pulp form 1) Wear materials (mixed use with other fibers, resin reinforcement) Break linings, clutch facings, bearings 2) Other packing materials, gaskets, filtration materials, abrasive materials 2. Cut fiber, chopped yarn paper (insulating paper, heat resistant paper, etc.), speaker vibration material, cement reinforcement material, resin reinforcement material 3. Filaments, spun yarns, yarns, tension members (optical fibers, etc.), ropes, and cords
The fiber of the present invention is not limited to the above applications, but has high strength and high elastic modulus, cut resistance, chemical resistance, abrasion resistance,
Since it is excellent in non-water absorption, it is particularly suitable for use as a tension member.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. [Melting point] 10 to 20 mg of a sample was placed in a DSC device (TA3000 manufactured by metrler) and sealed in an aluminum pan, and then N ₂ was supplied as a carrier gas at 100 cc / min, and a temperature rising rate was 20 ° C /
The temperature at the position of the endothermic peak is measured. [Logarithmic viscosity] 0.1% by weight of the sample was dissolved in pentafluorophenol (60 to 80 ° C), and the sample was dissolved in a 60 ° C constant temperature bath.
It is measured using a De-type viscometer, and is determined by ηinh = ln (ηrel) / c. [Strength and elastic modulus] According to JIS L 1013, the breaking strength and elongation and elastic modulus (initial tensile resistance) were obtained at a test length of 20 cm, an initial load of 0.1 g / d, and a tensile speed of 10 cm / min. The average value of is adopted. [Fibrill resistance] Depending on the amount of fibrils attached to the guide when the yarn is passed through a three-point titanium guide under a tension of 100 g and run at 100 m / min for 1 hour, those that do not attach at all are marked with "○". ], The one with a lot of adhesion is "x",
The middle one was evaluated as "△". [Cut resistance] The blade of a cutter knife is fixed to an Instron type universal testing machine, a yarn having a yarn length of 30 cm is rotated around the blade to perform a tensile test, and the strength when the yarn is cut is shown. [Water absorption] Approximately 2 g of sample was dried in a vacuum dryer (60 ° C x 6
hr) and then left in a humidity-controlled desiccator for 1 week. Electronic balance (Metra AE16
0) and calculate the water absorption rate by the following formula. In addition, W is a sample weight (g) after humidity control, and W1 is a sample weight (g) after absolute drying. Water absorption rate (%) = (W−W1) / W1 × 100

<Example 1> 57 mol of p-acetoxybenzoic acid [A], 6-acetoxy-2-naphthoic acid [B]
A molten anisotropic aromatic polyesteramide was obtained from 3 mol, 25 mol of terephthalic acid [C], 20 mol of 4-4'-bisphenol [D], and 5 mol of p-aminophenol [E]. The melting point of this polymer is 350 ° C and the logarithmic viscosity is ηin.
h was 6.4 dl / g. The polymer has a nozzle diameter of 0.1 mm
From a spinneret having φ and 400 holes, melt spinning was performed at a draft temperature of 30 at a spinning temperature of 370 ° C., a spinning speed of 1000 m / min, a shearing speed of 55200 sec ⁻¹ , and a filament of 1500 denier / 400 f was obtained.
The fiber performance of the obtained spun raw yarn was as follows: strength (DT) = 9.1 g / d elongation (DE) = 1.4% elastic modulus (YM) = 580 g / d. The spun raw yarn was heat treated in nitrogen gas at 250 ° C. for 2 hours (strength 11.8 g / d, strength increase of about 30% of the spun raw yarn), and then heat treated in dry air at 320 ° C. for 10 hr. The heat-treated yarn obtained had almost no interfiber sticking. Table 1 shows the strength, elastic modulus, fibril resistance, abrasion resistance and cut resistance of the heat treated yarn. <Comparative Example 1 and Comparative Example 2> Spinning was performed in the same manner as in Example 1 and the obtained spinning raw yarn was used only in nitrogen gas (Comparative Example 1).
Alternatively, except only in dry air (Comparative Example 2),
Heat treatment was performed in the same manner as in Example 1. The heat treated yarn of Comparative Example 2 was colored. The performance of the heat treated yarn obtained is shown in Table 1. Comparative Example 3 p-acetoxybenzoic acid [A] 35 mol, 6
-Acetoxy-2-naphthoic acid [B] 30 mol, terephthalic acid [C] 17.5 mol, 4-4'-bisphenol [D]
A melt anisotropic aromatic polyesteramide was obtained from 12.5 mol and 5 mol of p-aminophenol [E]. The melting point of this polymer was 260 ° C. and the logarithmic viscosity ηinh was 5.9 dl / g. Except that the spinning temperature of the polymer was 280 ° C.
A 1500 d / 400 f filament was obtained in the same manner as in Example 1. The performance of the obtained spun raw yarn is as follows. Strength (DT) = 6.3 g / d Elongation (DE) = 1.2% Elastic modulus (YM) = 510 g / d This spun yarn was heat treated in the same manner as in Example 1. The performance of the heat treated yarn obtained is shown in Table 1. <Comparative Example 4> 57 mol of p-acetoxybenzoic acid [A], 6
-Acetoxy-2-naphthoic acid [B] 3 mol, terephthalic acid [C] 25 mol, 4-4'-bisphenol [D] 25
Molten anisotropic polyester was obtained. The melting point of this polymer was 355 ° C. and the logarithmic viscosity ηinh was 6.6 dl / g. The polymer was spun and heat treated in the same manner as in Example 1. The performance of the heat treated yarn obtained is shown in Table 1.

[0016]

[Table 1]

In Example 1, a fiber having excellent performance was obtained, but in Comparative Example 1, since the fiber was heat treated only in an inert gas, the crosslinking was insufficient and the abrasion resistance and the abrasion resistance were improved. It is a fiber with low fibrillation. On the contrary, in Comparative Example 2, since the heat treatment is performed only in the active atmosphere, the strength, elastic modulus, etc. are not sufficiently enhanced. Comparative Examples 3 and 4 have low performance because they use polymers other than the present invention.

Next, heat-treated aromatic polyesteramide yarn of Example 1 and polyarylate fiber (Vectran A-910).
, Aramid fiber (Kevlar-49) was compared for strength, elastic modulus, fibril resistance, cut resistance, and non-water absorption. The results are shown in Tables 2 and 3.

[0019]

[Table 2]

[0020]

[Table 3]

The aromatic polyesteramide fiber of the present invention shows excellent performance although it is slightly inferior to the polyarylate fiber in strength. Further, aramid fibers have low cut resistance and low abrasion resistance, and particularly low non-water absorption. A material having a low non-water-absorbing property has a low insulating property when used as a tension member such as an optical fiber.

[0022]

According to the present invention, it is possible to provide a high-strength, high-modulus aromatic polyesteramide fiber having improved abrasion resistance.

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[Procedure amendment]

[Submission date] February 23, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

In order to obtain the fiber of the present invention, it is necessary to heat-treat and / or draw-heat treat the spun yarn in order to improve strength, elastic modulus, abrasion resistance and cut resistance. Heat treatment, after the intensity and the increased less than 50% in an inert atmosphere, the heat treatment under inert atmosphere is performed. If powerful increased 50% or more under an inert atmosphere <br/>, then those be performed heat treatment under inert atmosphere <br/> lower oxidation and crosslinking reaction of the wear resistance does not sufficiently proceed Becomes Further, if the heat treatment is performed only in an active atmosphere, the strength and elastic modulus are not sufficiently increased, and the fiber of the present invention cannot be obtained. However, even an unheat-treated yarn can be used according to the application and purpose. The term "inert atmosphere" means in an inert gas such as nitrogen or argon or under reduced pressure, and means that the active gas such as oxygen is 0.1 vol% or less. The term "under an active atmosphere" means an atmosphere containing 1% or more of an active gas such as oxygen, preferably an oxygen-containing gas of 10% or more, and it is preferable to use air in terms of cost. In the presence of water, the hydrolysis reaction proceeds in parallel, so the dew point is -20 ° C.
Below, preferably a dry gas of -40 ° C or less is used.

Claims (1)

[Claims] 1. The following [A], [B], [C], [D],
The content of the repeating structural unit of [E] is 90% by weight or more, and [A]: [B]: [C]: [D]: [E] = 100:
Consisting of an aromatic polyester amide having a molar ratio of 1 to 20: 5 to 100: 2 to 80: 2 to 20 and having a strength of 2
Melt anisotropic polyester amide fiber having 0 g / d or more and elastic modulus of 850 g / d or more. [Chemical 1]