JPH073526A - Polyamide-based fiber - Google Patents

Abstract

PURPOSE:To obtain a fiber having characteristics excellent in dyeing property and abrasion resistance and being low in absorbing property and being lightweight and suitable for uses such as ropes, nets, carpets and textile. CONSTITUTION:In a polyamide-based fiber using a polyamide-based resin composition consisting of a polypropylene resin, a polyamide resin and a modified polyolefin, this polyamide-based fiber is characterized in that a weight ratio of polypropylene resin/polyamide resin in the polyamide-based resin composition is >=0.02 and <0.89 and an amount of the modified polyolefin is 1-35 pts.wt. based on 100 pts.wt. total amount of polypropylene resin and polyamide resin and a ratio etaPP/etaPA of melt viscosity of polypropylene resin and polyamide resin at 260 deg.C and 1000sec<-1> shear rate is >=0.22. Thereby, a lightweight polyamide causing no end breakage in spinning, having good dyeing property, excellent in abrasion resistance and free from dimensional change due to water absorption and lowering of mechanical strength is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide fiber having excellent dyeability and abrasion resistance, low absorbency and light weight.

[0002]

2. Description of the Related Art Polyamide fiber has excellent physical and chemical properties, good dyeability, excellent abrasion resistance, high strength and excellent creep properties.
Used for nets, carpets, clothing, etc. However, there is a dimensional change due to water absorption and a decrease in mechanical strength, it is heavier than polyolefin fiber, becomes even heavier due to water absorption when wet, and a drying step is also required during spinning, which is a complicated process and leads to cost increase. Have.

In order to improve the drawbacks of polyamide fibers,
It has also been attempted to mix a polypropylene resin with a polyamide resin, but the resin mixture obtained by mixing by a usual method or the resin composition obtained by simply melt-kneading has poor compatibility,
Stretchability is poor, many melt fractures occur, deteriorated products tend to adhere to the nozzles, spinning breaks occur frequently, and continuous operation for a long time is difficult.

It is also attempted to obtain a composition having a good balance of strength, heat distortion resistance, appearance and molding processability by melt-mixing a modified polyolefin obtained by grafting an unsaturated carboxylic acid or its derivative with a polyamide resin. (Japanese Patent Publication No. 45-30945, Japanese Patent Publication No. 50-763)
No. 6). However, even with such a resin composition, there are various problems such as a significant decrease in strength, dyeing property, and no improvement in abrasion resistance, so that the use is considerably limited, especially in the field of fibers. However, when the compatibility is poor, there is a problem such as spinning breakage, and there is a problem that the dyeability and abrasion resistance are not sufficiently improved even if it is made into a fiber.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, spinning breakage does not occur, dyeability of fibers is good, abrasion resistance is excellent, and
An object of the present invention is to provide a lightweight polyamide-based fiber that does not have a dimensional change due to water absorption and a decrease in mechanical strength.

[0006]

Means for Solving the Problems As a result of intensive investigations by the present inventors to improve the defects while maintaining the excellent properties of polyamide fibers, as a result, it was found that a specific polyamide resin, a polypropylene resin and a modified polyolefin are used. It has been found that the surface layer of the fiber using the polyamide resin composition is covered with polyamide, and the present invention has been completed.

That is, the gist of the present invention is to provide a polyamide fiber using a polyamide resin composition comprising a polypropylene resin, a polyamide resin and a modified polyolefin, wherein the weight ratio of polypropylene resin / polyamide resin in the polyamide resin composition is Is 0.02 or more 0.8
Less than 9, the amount of modified polyolefin is 1 to 35 relative to 100 parts by weight of the total amount of polypropylene resin and polyamide resin.
In other words, the polyamide fiber is characterized by having a melt viscosity ratio η _PP / η _PA of 0.22 or more at a temperature of 260 ° C. of a polypropylene resin and a polyamide resin and a shear rate of 1000 sec ⁻¹ .

The polyamide resin (A) used in the present invention is not particularly limited, but polylactams such as polyamide 6, polyamide 11 and polyamide 12, dicarboxylic acids and diamines such as polyamide 66, polyamide 610, polyamide 612 and polyamide 46. Polyamides obtained from, polyamide 6/66, polyamide 6/1
2, copolymer polyamides such as polyamide 6/66/610, polyamide 6 / 6T (T: terephthalic acid component),
Semi-aromatic polyamides obtained from aromatic dicarboxylic acids such as isophthalic acid and metaxylene diamine or alicyclic diamine, polyester amides, polyether amides and polyester ether amides can be mentioned, among which polyamide 6 resin Is preferable because it has good spinnability.

The polypropylene resin (B) used in the present invention is a propylene homopolymer or a propylene copolymer. As the propylene copolymer, propylene-
There are ethylene copolymers, propylene-butene-1 copolymers, and the like, and block copolymers and random copolymers thereof are used. These polypropylene resins may be used alone or in combination of two or more.
Melt flow rate of polypropylene resin (JIS K
6758, hereinafter also referred to as MFR) is generally 1 to 50 g / 10 min, 5 to 30 g
/ 10 minutes is preferred.

As the modified polyolefin (C) used in the present invention, there are various kinds, but usually, a carboxylic acid group (acetic acid group, acrylic acid group, methacrylic acid group, fumaric acid group, itaconic acid group, etc.), Carboxylate metal base (sodium salt, calcium salt, magnesium salt, zinc salt, etc.), carboxylic acid ester group (methyl ester group, ethyl ester group, propyl ester group, butyl ester group, vinyl ester group, etc.), acid anhydride group A polyolefin having at least one functional group selected from (maleic anhydride group and the like) and epoxy group.

Here, as the polyolefin, polyethylene, polypropylene, polybutene, ethylene / propylene copolymers, ethylene / butene copolymers, ethylene / hexene copolymers, and copolymers containing a small amount of a diene in these are mentioned. I can give you. The MFR of the modified polyolefin is generally 0.01 to 100 g / 10 minutes, preferably 0.1 to 10 g / 10 minutes. These modified polyolefins may be used alone or in combination of two or more.

The (A) polyamide resin and (B) polypropylene resin used in the present invention have a temperature of 260.
The ratio (η _PP / η _PA ) of the respective viscosities η _PA and η _PP at ⁰ ° C. and a shear rate of 1000 sec ⁻¹ must be 0.22 or more, preferably 0.70 or more,
1.10 or more is particularly preferable. When η _PP / η _PA is less than 0.22, the dyeability and abrasion resistance of the obtained fiber are not sufficient.

The weight ratio of polypropylene resin / polyamide resin in the polyamide resin composition according to the present invention is 0.0
It is 2 or more and less than 0.89, and preferably 0.20 or more and less than 0.7. If the weight ratio of polypropylene resin / polyamide resin in the polyamide resin composition is less than 0.02, dimensional change due to water absorption and mechanical strength decrease may occur.
When it is 0.89 or more, the dyeability and abrasion resistance are not sufficient.

The amount of the modified polyolefin in the polyamide resin composition is 1 to 35 parts by weight, preferably 5 parts by weight or more and less than 21 parts by weight, based on 100 parts by weight of the total amount of the polypropylene resin and the polyamide resin. When the amount of the modified polyolefin is less than 1 part by weight, it is difficult to improve the compatibility of the polyamide resin and the polypropylene resin, the desired physical properties cannot be imparted to the obtained fiber, and the nozzle portion is deficient at the time of spinning. It frequently occurs, and spinning breakage easily occurs during long-term operation. On the other hand, when the amount of the modified polyolefin exceeds 35 parts by weight, a drying step becomes necessary, the physical properties of the obtained fiber deteriorate, and the cost increases.

If necessary, other additives may be added to the polyamide resin composition within a range that does not impair the characteristics of the components (A), (B) and (C). As additives, dyes, pigments, fillers, nucleating agents, fibrous materials, plasticizers, lubricants, release agents, coupling agents, foaming agents, heat-resistant agents, weather-resistant agents, flame retardants, antistatic agents, sliding agents. Agents and the like.

The polyamide resin composition is prepared by mixing or kneading the respective components, and as the method therefor, a conventionally known melt kneading method can be used. Mixing is performed using a Banbury mixer, a Henschel mixer, etc., and as a kneader, a single-screw or twin-screw extruder is generally used. There is no particular limitation on the order of compounding, and each component may be compounded sequentially or simultaneously,
Further, the components (B) and (C) may be blended with the powdery or pelletized component (A) after completion of the polymerization reaction.
The temperature at the time of melt-kneading may be appropriately selected depending on the components, the blending amount, etc., at which the melting of each component sufficiently progresses and does not decompose, and it is usually 180 to 350 ° C., and 200 to 3
00 ° C is preferred.

The polyamide-based fiber of the present invention comprises a polyamide-based resin composition, and a polyamide-based resin composition
0 to 2000 sec ^-1 , preferably 500 to 1600 s
It is obtained by melt spinning at a shear rate of ec ⁻¹ , particularly preferably 700 to 1200 sec ⁻¹ and a die temperature of 220 to 330 ° C., preferably 240 to 280 ° C. The melt spinning nozzle may have any shape,
The nozzle cross-sectional area is 0.503 to 3.14 mm ² , and the nozzle shape is preferably circular or elliptical with an aspect ratio of 1.0 to 1.6. Cooling is performed after spinning, but the cooling temperature is 20
It is preferable to keep the temperature below ° C. Stretching is performed with a pressurized steam tank,
Any combination of a hot air bath, a heating medium bath, a hot plate, a hot roll, a wet bath, etc. may be used, but multi-stage stretching is preferred, and the first stage is wet-stretching, and the second and subsequent stages are hot-rolling. The combination is most preferred. The draw ratio of each stage is set to be 0.2 to 0.5 times lower than the white turbidity start ratio of each stage, and the stretching temperature is suitably 80 ° C. or higher.

[0018]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, each physical-property value of an Example and a comparative example was measured by the following method. (1) Dyeability test As a dye, KNH Red RS12 manufactured by Nippon Kayaku Co., Ltd.
Sample No. 5 was diluted with water to a dye concentration of 1%, the sample was immersed in a boiled dye solution for 2 hours and then pulled up, and the dyeing level was visually evaluated on a scale of five. A: It is dyed very well. (Equivalent to 100% nylon) B: Stained well. C: It is dyed. D: It can be confirmed that it is dyed. E: Not dyed at all.

(2) Abrasion resistance A sample subjected to a constant load was brought into contact with an abrasion roller wound with sandpaper 120AA, and the roller was rotated to evaluate the number of rotations until cutting. Load is 100
g and 200 g were performed.

(3) Necessity of Drying Step After pelletizing with a twin-screw extruder, when it is applied to an extruder for spinning, there is no spinning that can be spun even if it is supplied to the hopper without drying. I said. Further, when spinning cannot be performed due to foaming at the nozzle outlet, it was left in a vacuum dryer (80 ° C.) for about 3 to 4 hours and then fed to a hopper to try spinning. And the thing which became able to spin by it was made "existence".

(4) Surface Observation Fibers were immersed in a solution prepared by mixing a 2% phosphotungstic acid aqueous solution and a 2% benzyl alcohol aqueous solution for 48 hours and then taken out, and SEM observation of the fiber surface was performed by backscattered electrons. The polypropylene resin part is dyed black and the polyamide resin part is not dyed and remains white. From this, it was determined whether the fiber surface was mainly a polypropylene resin layer or a polyamide resin layer.

Example 1 Polyamide 6 having a relative viscosity of 2.50 and an amino terminal concentration of 4.9 × 10 ⁻⁵ equivalent / g was used for 12.
0 Kg and 8.0 Kg of propylene homopolymer having MFR of 2.7 g / 10 min (PP / PA6 weight ratio = 0.6
7) and 2.0 kg (10 parts by weight) of graft-modified polypropylene obtained by adding 0.35% by weight of maleic anhydride to isotactic polypropylene having an MFR of 25 g / 10 are mixed in a tumbler for 10 minutes and then 40 mm.
Melt pelletizing was performed at 250 ° C. with a φ2 screw extruder to obtain a polyamide resin composition. 260 ° C, shear rate 10
The melt viscosity ratio at 00 sec ⁻¹ was η _PP / η _PA = 1.15. This polyamide resin composition was extruded at 260 ° C. by a 40 mmφ monofilament manufacturing apparatus equipped with 20 1 mmφ nozzles, the strand discharged from the nozzle was rapidly cooled with 30 ° C. water, and then unstretched by a first roll. The yarn was wound up, guided in-line to a wet drawing tank (100 ° C.), and wound up by a second roll. The draw ratio was represented by the speed ratio of the second roll and the first roll, and was molded at 4 times. The thickness of the obtained polyamide fiber is 400 denier, and the shear rate at the nozzle is 100.
It was ⁰ sec ^-1 . The obtained polyamide fibers are shown in Table 1.
It was confirmed that the dyeing property and the abrasion resistance were excellent as shown in (1), and the surface observation revealed that many polyamide layers appeared on the surface.

(Examples 2 to 3) Polyamide fibers were molded in the same manner as in Example 1 except that the weight ratio of polypropylene resin / polyamide resin was changed. The results are shown in Table 1.

(Examples 4 to 5) Polyamide resin having a relative viscosity of 3.5 and an amino terminal concentration of 4.9 × 10 ⁻⁵ equivalent / g
Except that the polyamide 6 of 6 or a relative viscosity of 1.5 and an amino terminal concentration of 4.9 × 10 ⁻⁵ equivalent / g of polyamide 6 were used.
A polyamide fiber was molded in the same manner as in Example 1.
The results are shown in Table 1.

(Examples 6 to 7) Graft-modified polypropylene was added in a total amount of polypropylene resin and polyamide resin of 1
A polyamide fiber was molded in the same manner as in Example 1 except that the amount was 5 parts by weight or 20 parts by weight with respect to 00 parts by weight. The results are shown in Table 1.

Example 8 A polyamide fiber was molded in the same manner as in Example 1 except that the shear rate at the nozzle of the monofilament manufacturing apparatus was set to 500 sec ^-1 . The results are shown in Table 1.
Shown in.

Comparative Examples 1 and 2 Polyamide fibers were molded in the same manner as in Example 1 except that the weight ratio of polypropylene resin / polyamide resin was 0.95 or 0.11. The results are shown in Table 1.

Comparative Examples 3 to 4 Graft-modified polypropylene was added in a total amount of 1 of polypropylene resin and polyamide resin.
Polyamide fibers were molded in the same manner as in Example 1 except that 0.5 parts by weight or 40 parts by weight was used with respect to 00 parts by weight. The results are shown in Table 1. In particular, when the graft modified polypropylene was 0.5 part by weight, molding could not be performed.

Comparative Example 5 Polyamide 6 having a relative viscosity of 5.5 and an amino terminal concentration of 4.9 × 10 ⁻⁵ equivalent / g was used as the polyamide resin, and η _PP / η _PA was 0.20. A polyamide fiber was molded in the same manner as in Example 1. The results are shown in Table 1.

[0030]

[Table 1]

[0031]

EFFECTS OF THE INVENTION A lightweight polyamide fiber was obtained in which spinning was not broken, the dyeability of the fiber was good, the abrasion resistance was excellent, and the dimensional change and mechanical strength did not decrease due to water absorption. In the case of a blended system of resins, it often shows average properties, but in the case of the present invention, since the polyamide resin appears preferentially on the fiber surface, the dyeability, despite containing the polypropylene resin, It is considered that the excellent surface properties of the polyamide resin such as abrasion resistance were developed.

Front page continuation (72) Inventor Ryosuke Kamei 1-13-9 Shibadaimon, Minato-ku, Tokyo Showa Denko KK

Claims (1)

[Claims] 1. In a polyamide fiber using a polyamide resin composition comprising a polypropylene resin, a polyamide resin and a modified polyolefin, the weight ratio of polypropylene resin / polyamide resin in the polyamide resin composition is 0.02 or more. Less than 0.89, the amount of the modified polyolefin is 1 to 35 parts by weight based on 100 parts by weight of the total amount of the polypropylene resin and the polyamide resin, and the melt viscosity of the polypropylene resin and the polyamide resin at a temperature of 260 ° C. and a shear rate of 1000 sec ⁻¹ . A polyamide fiber having a ratio η _PP / η _PA of 0.22 or more.