JPH0754229A - Composite yarn - Google Patents

Abstract

PURPOSE:To obtain a composite yarn, excellent in handleability and process passableness and having high mechanical characteristics and aesthetic properties by using polybenzazole continuous filament yarn as core yarn and covering the outer periphery thereof with dyeable fiber. CONSTITUTION:This composite yarn is obtained by guiding polybenzazole continuous filament yarn 2 withdrawn from a bobbin 1 for core yarn through a yarn passage guide 3, a tension regulator 4 and a yarn passage guide 5 to feed rolls 6, then passing the filament yarn through a hollow spindle 7, further delivery rolls 8 and a yarn passage guide 9 and then guiding the yarn to a bobbin 12 for winding on a friction roll. A bobbin 11 for sheath yarn is fitted onto the hollow spindle 7 and rotated with a driving belt running in contact with the lower part of the spindle 7. Dyeable fiber 10 withdrawn as the sheath yarn is then wound around the outer periphery of the polybenzazole continuous filament yarn into a coiled form to form the composite yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite yarn which has excellent mechanical properties, is easy to handle during weaving and knitting, and has a good aesthetic appearance when formed into a fabric. More specifically, the present invention relates to a composite yarn suitable as a material for clothing similar products such as bulletproof vests, helmets, protective gloves and aprons, which require high mechanical properties and aesthetics.

[0002]

2. Description of the Related Art Conventionally, wholly aromatic polyamide fibers and wholly aromatic polyester fibers are used in the field of protective articles such as uniforms, seat belts and safety belts by taking advantage of their high strength, heat resistance and chemical resistance. Have advanced to. In recent years, general clothing approximation products, such as sports / leisure suits, having excellent functionality using a blended yarn or blended yarn of polyethylene terephthalate fiber or polyamide fiber and the wholly aromatic polyamide fiber or wholly aromatic polyester fiber have been developed. Being developed. Recently, polybenzazole having high mechanical properties (for example, tensile strength over 4.0 GPa and high initial elastic modulus over 140 GPa) and high heat resistance and flame retardancy (for example, decomposition initiation temperature 670C, limiting oxygen index 56). Industrial production technology of fibers (PBZ fibers) has been developed. Along with this, the fiber has come to be noticed not only as an industrial material but also as a material for the above-mentioned clothing similar products.

[0003]

However, since polybenzazole fibers generally have a yellow to brown color tone and are non-staining with ordinary dyes, they are limited in their use as clothing similar products in terms of color tone. Receive. Conventionally, in order to eliminate these obstacles, there is a method such as plying or twisting the polybenzazole fiber with a dyeable fiber or a dyed fiber with an ordinary dye, or entanglement using compressed air. Has been considered. However, in the case of a compound yarn obtained by performing a compounding yarn or a twisting process, the dyeable dyed fiber often changes the surface color tone periodically or exhibits a marbling tone. A fabric woven and knitted from such a composite yarn having a non-uniform color tone has a problem that a pattern called wood grain or moire is likely to be formed on the surface. Further, it is also considered to modify the dyeability by a method of copolymerizing a monomer having a dyeing seat or a method of disturbing the regularity of the fine structure by introducing a third component. However, the mechanical and thermal properties of the fiber are likely to be sacrificed and the raw material cost is increased. An object of the present invention is to eliminate these drawbacks derived from the non-staining property of polybenzazole fibers and to provide a composite yarn having a color tone which can be applied to clothing approximation products.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that the mechanical characteristics can be improved by specifying a combination of polybenzazole fiber and a fiber dyeable with an ordinary dye. The present invention has been accomplished by finding that the color tone is improved without impairing it. That is, in a composite yarn consisting of polybenzazole continuous fibers and dyeable fibers, the main purpose is a composite yarn in which the above-mentioned polybenzazole continuous fibers are used as core yarns and the outer periphery thereof is coated with fibers dyeable with ordinary dyes. It is what

The present invention will be described in detail below. The polybenzazole fiber (PBZ fiber) used in the present invention is obtained by spinning a dope composed of polybenzoxazole (PBO), polybenzthiazole polymer (PBT), or a random or block copolymer thereof. And tensile strength of more than 4.0 GPa and 140 GPa
It is preferable to have the above initial elastic modulus.

The dyeable fibers of the present invention can be dyed with direct dyes, vat dyes, naphthol dyes, sulfur dyes, disperse dyes, reactive dyes, acid dyes, cationic dyes, etc. and are used for general clothing and industrial purposes. The natural fibers such as cotton, wool, animal hair, hemp, etc., and chemical fibers or synthetic fibers such as rayon, cupra, acetate, polyester, polyamide, acrylic, vinylon, etc. are exemplified, and it is optional depending on the purpose. Fiber can be selected. The dyeable fiber may be dyed in advance, or a synthetic fiber such as polyester or polyamide may be a spun yarn in which a pigment is mixed with a polymer. It is preferable that the fibers dyeable with the usual dyes used in the present invention have as low shrinkage as possible. This is because when the polybenzazole fiber has a very low heat shrinkability and the composite fiber has a high shrinkage, the polybenzazole fiber becomes looped during the heat treatment of the cloth, although it depends on the difference in the heat shrinkage.

In the composite yarn of the present invention, it is important to dispose the twisted polybenzazole filaments having high tensile strength and high initial elastic modulus in the core or inner layer thereof. Here, the twisted state means that the twist coefficient is in a range satisfying the following formula. 10 ≦ D ^0.5 × Tw ≦ 80 D; yarn fineness (denier) Tw; number of twists (times / inch)

When the twisting coefficient of the polybenzazole continuous fiber is less than 10, when the dye is mixed with the dye-dyable fiber, the mechanical properties of the single fiber are rubbed and damaged depending on the compounding means. Indicates a downward trend. That is, the ratio (retention rate) of the strength after the composite to the strength of the polybenzazole continuous fiber before the composite is likely to decrease. On the other hand, the twist coefficient is 80
If it exceeds, the mechanical properties are deteriorated due to the twist of the single fiber.
Therefore, the twist coefficient is preferably 10 to 80. In this way, the twisted polybenzazole filaments are arranged in the core part or the inner layer part, and the sheath part or the outer layer part is arranged in the outer layer part by coating with a fiber dyeable with an ordinary dye. The composite yarn can be made to have an arbitrary color tone with the above fibers. In addition, since the polybenzazole fiber is in a state of being covered with other fibers, the sizing property as a composite yarn is also good, and the occurrence frequency of troubles such as yarn cracking and catching during rewinding or weaving or weaving the yarn. And the process passability is improved. Further, in the application of thermosetting or impregnation with a thermoplastic resin, the adhesiveness is improved as compared with the case of using polybenzazole fiber alone.

The content of the dye-dyable fiber in the composite material of the present invention is 0.15 to 0.45 (weight ratio).
In this case, a favorable balance of tensile strength, initial elastic modulus, coverage and focusing property can be obtained. If the content ratio of the dyeable fiber to the dye is less than 0.15, the polybenzazole continuous fiber arranged in the core part is partially exposed to impair the aesthetics. Further, since the bundle-converging property of the composite yarn is lowered, problems such as yarn cracking and catching are likely to occur during rewinding of the yarn and weaving and knitting. On the other hand, if the content ratio exceeds 0.45, the amount of polybenzazole fiber decreases, and it becomes difficult to achieve the desired tensile strength and initial elastic modulus. Further, when synthetic fibers such as polyester and polyamide are used as dyeable fibers for ordinary dyes, the mechanical properties and handleability of the composite yarn are improved.

In the production of the composite yarn of the present invention, (1) a polybenzazole continuous fiber is used as a core yarn, and the dyeable continuous fiber is wound around the outer periphery as a sheath yarn in a spiral shape (2). (3) The outer circumference of the polybenzazole continuous fiber is formed by using polybenzazole continuous fiber as a core yarn, and applying the dyeable short fiber around the core yarn to bind the terminal end of the short fiber by the action of air flow. Appropriate methods can be adopted, such as covering with a short fiber fleece, and further winding another dyeable fiber thread around the outside in a coil shape to bind it.

FIG. 1 shows an example of an apparatus for producing a composite yarn by the method (1), in which the polybenzazole continuous fiber 2 drawn from the core yarn bobbin 1 is a yarn guide 3, After being guided to the supply roll 6 through the tension adjusting device 4 and the yarn guide 5, and passed through the spindle 7 having a hollow inside, the winding on the friction roll is further performed through the delivery roll 8 and the yarn guide 9. Is guided to the bobbin 12. The hollow spindle 7 has a dyeable fiber thread 10 serving as a sheath thread.
A bobbin 11 for wound sheath yarn is fitted and is rotated by a drive belt running in contact with the lower portion of the hollow spindle 7, and the dyeable synthetic fiber yarn 10 is drawn out from the bobbin 11 for sheath yarn. Is wound around the outer periphery of the polybenzazole filament 1 in a coil shape to form a composite yarn.

Each scale used for evaluation in the present invention was determined by the following method. <Fineness> Samples in standard condition (temperature 22 + 2 degrees, relative humidity 6
After standing still for 24 hours in a test room (5 + 2% state), 90 m of a sample was sampled using a lap reel, and its weight was measured and converted into a weight of 9000 m to obtain a fineness. <Tensile Strength / Initial Elastic Modulus> JIS L1013 (198
In accordance with 7.5.1 of 1), using a Tensilon type tester manufactured by Orientec Co., Ltd. in a standard condition test room, a gripping interval of 20 cm, a pulling speed of 100% / min and n = 10 The strength and elongation of the strip was measured. <Fiber mixed state> The cross section of the resin-embedded composite yarn is cut using a diamond cutter, a micrograph of the cut end is taken, and the dispersed state of the fiber is visually determined. <Determination of color spots on fabric> The uniformity of color tone was visually determined. The polybenzazole fiber has a uniform color tone without being exposed on the surface of the fabric, ○, the color tone of the polybenzazole fiber is a little light color Δ, and the moire pattern or marbling is evaluated as x. did.

[0013]

【Example】

Examples 1 and 2 Nylon 6 long fibers having a fineness of 75 denier and 36 filaments were wound around polybenzoxazole long fibers (PBO fibers) having a fineness of 250 denier at a rotation speed of 300 times per 1 m using the apparatus shown in FIG. The obtained composite yarn was rewound and warped and woven. The resulting fabric was treated with an acid dye (Fast Navy Blue R.C.I.
13390) and printing at 100 ° C. for 30 minutes, and this is referred to as Example 1. In place of the long nylon fiber in the above Example 1, a nylon processed yarn having a fineness of 75 denier and 36 filaments was used, and this was set as Example 2.

Comparative Example 1 Polybenzoxazole long fibers having a fineness of 250 denier and nylon long fibers having a fineness of 75 denier and 36 filaments were combined and twisted at a twist number of 150 times / m to obtain a composite yarn. Using this composite yarn, weaving and dyeing were performed under the method and conditions described in Example 1, and this was set as Comparative Example 1.

Example 3 In place of the nylon filaments in Example 1, polyethylene terephthalate filaments having a fineness of 75 denier and 36 filaments were used to fabricate a composite yarn, which was further woven into a fabric. The cloth was treated with a disperse dye (CI Disperse Blue 1, CI 64).
500) high temperature dyeing (wet heat 120 ° C x 40 minutes)
Was carried out, and this was designated as Example 3.

<Embodiment 4> The winding section of an ordinary spinning machine is modified into a cheese winding method, a swirling nozzle is attached immediately after the front roll, and a polyester staple fiber (fineness 1 4 denier, cut length 51m
m) is fed to form a fleece. On the other hand, polybenzoxazole long fibers having a fineness of 250 denier were fed from directly above the front roll to overlap the center of the fleece, and these were passed through the swirling nozzle and processed at an air pressure of 4.0 kg / cm ² to obtain dyeable fibers. Ratio of 30
% Composite yarn was obtained. The composite yarn is woven into a cloth, and the cloth is prepared by using a disperse dye (CI Disperse Bl).
ue1, C.I. I64500) high temperature dyeing (wet heat 1
20 ° C. × 40 minutes).

<Comparative Examples 2 to 3> In Example 1, the polybenzoxazole fiber was replaced with a polyparaphenylene terephthalamide fiber having a fineness of 200 denier (trade name of Kevlar 29 DuPont) as Comparative Example 2 and a fineness of 400. Comparative Example 3 was the case where denier ultra high molecular weight polyethylene fiber was used instead. The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 3 are summarized in Table 1.

[0018]

[Table 1]

From Table 1, in Examples 1 to 3 which belong to the present invention, the handling property and the process passing property of the composite yarn from the rewinding to the weaving were good. Further, the decrease in the strength of the polybenzoxazole fiber due to the combination was not a problem in practical use. The fabric obtained by weaving the composite yarn was dyed, but no moire pattern was observed.
In Example 4 belonging to the present invention, the outer layer portion was covered with the polyester short fibers, so that the obtained cloth had a soft texture and the color tone after dyeing was uniform. On the other hand, in Comparative Example 1 which does not belong to the present invention, the single yarn did not crack in the process of rewinding the composite yarn, but the dyed fabric exhibited a marbling tone. The composite yarns of Comparative Examples 2 to 3 were good in handling property and process passing property, and the polyparaphenylene terephthalamide fiber or the ultrahigh molecular weight polyethylene fiber after the composite had a slight decrease in strength. No moire pattern or marbling pattern occurred on the dyed fabric made of the composite yarn. However, the strength of the composite yarn was lower than those of Examples 1 to 4.

[0020]

INDUSTRIAL APPLICABILITY In the composite yarn of the present invention, polybenzazole filaments are arranged in the core, and the high mechanical properties thereof are maintained without being impaired, and the surface of the yarn may be a conventional dye. Since it is covered with dyeable fibers, there is no yarn crack between single yarns, and the handling of yarns from the rewinding process to the weaving process becomes easy. In addition, since the unique color tone of the polybenzazole fiber is hidden by another dyeable fiber, it becomes possible to impart aesthetics to the fabric. Therefore, the fabric composed of the composite yarn can be used for clothing approximation products having both high functionality and aesthetics, such as bulletproof vests, helmets, protective gloves, and aprons.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus showing an example of a composite method used in the present invention.

[Explanation of symbols]

 1 bobbin for core yarn 2 polybenzazole long fiber 3 yarn guide 4 tension adjusting device 5 yarn guide 6 supply roll 7 hollow spindle 8 delivery roll 9 yarn guide 10 dyeable fiber yarn 11 sheath yarn bobbin

Claims (1)

[Claims] 1. A composite yarn comprising a polybenzazole continuous fiber and a dyeable fiber, wherein the polybenzazole continuous fiber is used as a core yarn, and the outer periphery thereof is coated with a dye-stainable fiber. And composite yarn.