JP2820976B2 - Composite fiber excellent in dimensional stability and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a conjugate fiber having excellent dimensional stability and a method for producing the same.

[Conventional technology]

The dimensional stability of woven or knitted fabric is a dimensional change under the conditions where the potential of stress or heat shrinkage due to the characteristics of the fabric material and the history received in the process in which they were manufactured, as well as the stress or heat shrinkage force, will be used or treated. What appears,
These are problems such as shrinkage at the time of extension in the sewing process, shrinkage of the iron press, and shrinkage of the washing during practical use. Also, in the finishing process before the sewing process, that is, in the steps of heat setting, scouring / dyeing, greige, etc., the dimensional stability of the greige and fiber itself (shrinkage in case of fiber) Gender may be more appropriate).

In the case of natural fibers such as protein fibers and cellulosic fibers, swelling in the fiber diameter direction mainly due to moisture, shrinkage of the fabric due to shrinkage in the fiber axis direction, and shrinkage in the case of synthetic fibers are caused by spinning and drawing of yarn. If the stress or heat shrinkage force remains in the fabric, such as when the strain received in the process is not sufficiently relaxed or when the fabric is forcibly stretched, it shrinks due to the action of heat and moisture in the iron press process. As described above, the shrinkage of the fabric is determined by the shrinkage force of the fiber itself and the amount of shrinkage of the fabric, but the first problem to be addressed in order to improve the dimensional stability is the fiber itself. It is proper to determine the knitting structure and density according to the degree and application.

The thermal stability and heat resistance of a fiber are greatly affected by its crystallinity. The crystal part of the molecular chain constituting the fiber is extremely rigid and stable against heat. On the other hand, in the amorphous part, the molecular chain easily moves and is unstable against heat.

In the field of synthetic fibers, it is known that heat resistance can be increased by introducing an aromatic ring into a molecular main chain. This is because the rigidity of the main chain is increased by introducing an aromatic ring and
This is due to effects such as an increase in -H bonding force.

At present, polyethylene terephthalate (PET) fiber is one of the most important versatile fibers. PET fibers are melt-spinnable, have appropriate elongation and strength, have some degree of thermal stability, and are excellent in dyeability. Due to its many strengths, its applications are wide regardless of the garment field, interior field, and industrial field. It belongs to aromatic polyester and is a crystalline fiber having an aromatic ring in the main chain, but its heat resistance is hard to say because the ratio of the aromatic ring is small.

Aromatic polyamides are known as heat resistant fibers. This is a fiber first commercialized by Dupont in 1967, but due to poor dyeing properties and weather fastness, protective clothing,
Its applications, such as laundry supplies and electrical insulation materials, are limited. Attempts have also been made to improve the sulfone groups to improve the dyeing properties (JP-B No. 45-34766), but the strength, Young's modulus, heat shrinkage, etc. are inferior to those of ordinary ones.
It deviates from its original purpose. In addition, since this fiber is manufactured by a wet spinning method, the process is complicated, and it is difficult to develop applied materials.

In recent years, polyphenylene sulfide polymers have been developed as polymers that can be melt-spun and have heat resistance and flame retardancy. Since the polymer is rich in crystallinity and has a high proportion of aromatic rings, its crystals are extremely rigid and have high thermal stability. In addition, since melt spinning is possible, production on the currently operating polyester machine is basically possible.
There is great expectation as a general-purpose high-performance fiber replacing PET fiber. However, not all polymers have cleared the performance of polyester fibers, such as the high crystallinity of the polymer, the poor dyeability and the unpleasant feeling of the yarn.

As described above, various heat-resistant fibers are developed and marketed today, but their evaluation is not complete.

[Problems to be solved by the invention]

Accordingly, an object of the present invention is to provide a conjugate fiber which can be melt-spun, has excellent dimensional stability to heat, has good dyeability, and is inexpensive, and a method for producing the same.

[Means for solving the problem]

We have: A fiber in which a polyphenylene sulfide polymer layer (A) having a main structural unit of and a polyester layer (B) containing polyethylene terephthalate or polybutylene terephthalate as a main component is mixed with hydrogen peroxide, an alkali metal hypochlorite, Alkaline earth metal hypochlorite, sulfuric acid, hydrochloric acid, sulfuryl chloride, nitrogen dioxide, chromium trioxide, alkali metal permanganate, nitric acid, organic peracid, lead tetraacetate, periodate, periodate, Or N-
By oxidizing with an oxidizing agent selected from halocarboxylic amides, fibers having excellent dimensional stability while utilizing the basic physical properties of polyphenylene sulfide polymer, excellent dyeing properties, and inexpensive fibers can be obtained. This has led to the present invention.

The polyphenylene sulfide polymer referred to in the present invention is composed of at least 90 mol% or more of p-phenylene sulfide units in the constitutional unit, and may contain a copolymer component in a proportion of 10 mol% or less. It is not a problem. For example, it can be a high polymer containing a crosslinking component based on less than 1 mol% of a trichlorobenzene monomer or a crosslinking component due to an oxidation reaction. If another example is shown, it is also possible to partially make a phenylene group into a biphenylene group, a naphthalene group or the like in the range shown above, and similarly, a part in which a part of a sulfide group is replaced with an oxide, a sulfon group or the like. Can be applied without departing from the gist of the present invention.

In the present invention, the polymer constituting the polymer layer (B) is a polyester containing polyethylene terephthalate or polybutylene terephthalate as a main component. For example, terephthalic acid, isophthalic acid, naphthalene 2,6-dicarboxylic acid, phthalic acid, α, β- (4-carboxyphenoxy) ethane, 4,4′-dicarboxydiphenyl,
Aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid or adipic acid, aliphatic dicarboxylic acids such as sebacic acid or esters thereof and ethylene glycol, diethylene glycol, 1,4-butanediol,
A fiber-forming polymer synthesized from diol compounds such as neopentyl glycol, cyclohexane-1,4-dimethanol, polyethylene glycol, and polytetramethylene glycol.
Particularly, a polyester in which 90 mol% or more is a polyethylene terephthalate unit or a polybutylene terephthalate unit. The polyester may contain a small amount of additives, fluorescent brighteners, stabilizers or ultraviolet absorbers.

In the present invention, the intended fiber is intended to be obtained by compounding a polyphenylene sulfide polymer and a polyester polymer. It has been found that dimensional stability is dramatically improved by treating with an oxidizing agent after weaving.

The oxidizing agent used for the treatment is hydrogen peroxide, alkali metal hypochlorite, alkaline earth metal hypochlorite, sulfuric acid, hydrochloric acid, sulfuryl chloride, nitrogen dioxide, chromium trioxide, alkali metal permanganate, It is selected from the group of nitric acid, organic peracids, lead tetraacetate, periodate, periodate or N-halocarboxamides. Many other substances exhibiting an oxidizing action exist, but the above-mentioned substances were selected in consideration of the object of the present invention. Next, an appropriate formulation for each treatment agent is shown.

Hydrogen peroxide, alkali metal hypochlorites or alkaline earth metal hypochlorites are used as aqueous solutions at concentrations ranging from 1.0% by weight to saturation. Sulfuric acid is used in aqueous solutions at concentrations ranging from 10% to 90%. Hydrochloric acid can be used as an aqueous solution of chlorine at a concentration ranging from 10% by weight to a saturated solution. Sulfuryl chloride is used as a halogenated hydrocarbon solution in concentrations ranging from 40 to 90% by weight. Nitrogen dioxide uses gas as it is. Chromium trioxide can be used as an aqueous solution at a concentration ranging from 1.0% by weight to a saturated solution. The alkali metal permanganate can be used as an aqueous solution at a concentration ranging from 1.0% by weight to a saturated solution. Nitric acid can be used as an aqueous solution at a concentration ranging from 20 to 80% by weight. Organic peracids can be used in aqueous solutions ranging from 1.0% to 80% by weight. Lead tetraacetate can be used up to a saturation concentration of 1.0% by weight using benzene and acetic acid as solvents. Periodic acid and periodate can be used as an aqueous solution in a concentration range from 1.0% by weight to a saturated solution. The N-halocarboxylic acid amide can be used in a concentration range from 1.0% by weight to a saturated solution using anhydrous methanol, methanol, benzene-methanol or the like as a solvent. Among the above formulations, particularly preferred treating agents are hydrogen peroxide, sodium hypochlorite, lead tetraacetate, sodium periodate, N-bromoacetamide, N-bromosuccinimide, N-bromophthalimide, 1-chlorobenzotriazole. Next, the method for producing a conjugate fiber of the present invention will be described.
FIG. 1 schematically shows a spinning apparatus according to the present invention. One of the two melt extruders has a polyphenylene sulfide polymer,
The other 2 is filled with a polyester polymer. By means of the extruder, the melt-extruded polymer streams are each precisely metered by a gear pump and sent to the spinning head.

The two kinds of polymer streams are combined by a packing fitting provided on a head, and thereafter discharged from a spinneret to be converted into fibers. The composite form of the polyphenylene sulfide polymer and the polyester polymer is selected according to the required performance of the fiber. For example, in a field where sufficient dyeing property is required, it is better that the polyester layer comes to the sheath side as shown in FIG. In the case where chemical resistance and heat resistance are required rather than dyeability, it is considered that the polyphenylene sulfide layer should be on the sheath side as shown in FIG.

A problem in the composite form of the fiber of the present invention is a balance with the oxidation treatment. The oxidation treatment acts on polyphenylene sulfide to improve the thermal stability and achieve the object of the present invention. for that reason,
The polyphenylene sulfide polymer layer should be placed on the sheath, and in the case of the core, the oxidation treatment becomes difficult,
It is generally thought that improvement in thermal stability cannot be measured. However, as a result of intensive studies by the present inventors, the oxidation treatment proceeded to the same degree regardless of the arrangement of the polyphenylene sulfide polymer layer regardless of the arrangement of the core portion and the sheath portion, and there was no difference in improvement in thermal stability. That is, from the viewpoint of dimensional stability to heat, the composite form of both polymers does not have to be particularly limited, and this fact has been made clear for the first time by the present invention.

Spinning speed is 1000m / min ~ 1,000sm as same as general fiber
/ min or high-speed spinning at 3000 to 5000 m / min. Polyphenylene sulphide polymers with cross-linking are poor in spinnability and break easily.However, non-cross-linked polymers are extremely excellent in spinning yarn and have good composites with polyester polymers. High-speed spinning is also possible, and there is no peeling. Stretching can be performed with a usual roller plate type stretching machine.

Hereinafter, the content of the present invention will be described in detail with reference to Examples, but the boiling water shrinkage (W ₁ ) and the dry heat shrinkage (W ₂ ) in the present specification refer to values obtained by the following methods.

l ₁ : Sample length before boiling water treatment measured under a load of 0.05 g / d l ₂ : Sample length after boiling water treatment measured under a load of 0.05 g / d ) And apply 0.5mg / d load for 30 minutes l ₃ : Sample length before dry heat treatment measured with a load of 0.05 g / d l ₄ : Sample length after dry heat treatment measured with a load of 0.05 g / d Treatment in 180 ° C dry hot air (50cm), 0.5mg
Example 1 Polyethylene terephthalate of [η] = 0.80 to which 0.5 wt% of TiO ₂ was added was extruded with a 40φ extruder, while a non-crosslinked type having a viscosity of 4000 poise (300 ° C. 10 sec) was applied. After extruding polyphenylene sulfide from a 40φ extruder, weighing each in a predetermined amount, it is flushed to the spinning pack, and discharged from a round hole nozzle,
Composite spinning was performed at a spinning speed of 1000 m / min. The cross section of the composite yarn is as shown in FIG. 3 (a), and the composite yarn is composited so that 20% of the total fiber surface area is occupied by polyphenylene sulfide.

The spun yarn is stretched with a roller plate, and is 75 denier.
Obtained a multi-filament of 24 filaments. About 1 g of the drawn yarn is made into a skein of about 3 cm in diameter, and in a sodium hypochlorite solution adjusted to pH 4.0 with acetic acid at a weight 50 times that of the yarn sample and corresponding to an effective chlorine concentration of 3.0 g /, in a sodium hypochlorite solution. Charge, immerse, 80 ℃
For 60 minutes. Then neutralize, wash, dry,
The boiling water shrinkage W ₁ and a dry heat shrinkage W ₂ after treatment were measured.

W ₁ is 0.5%, W ₂ is 1.7% and extremely low, the composite fiber is found to be excellent in dimensional stability against heat.

Meanwhile, a knitted fabric was knitted with a drawn yarn of the composite fiber, and a dyeing test was attempted. Dyeing was carried out using Eastman Polyester Navy Blue 3RLS at 2% owf, bath ratio 50: 1, 130 ° C. for 1 hour. When the dyeing rate was measured, it was 82%. As a control, the dyeing rate of the polyethylene terephthalate base dyed under the same conditions was 95%, which indicates that all of the composite polyethylene terephthalate polymers were dyed. The polyphenylene sulfide polymer portion exposed on the fiber surface by 20% was difficult to dye, so the color was a little light, but the leveling properties were good as a whole.

Example 2 Spinning, stretching, oxidation treatment, measurement of W ₁ and W ₂ , and dyeing were carried out under the same conditions as in Example 1 except that the arrangement of the polymer was reversed. W ₁ = 0.7% and W ₂ = 1.7%, almost the same results as in Example 1. The dyeing rate was 65%.

Comparative Example 1 The same drawn yarn used in Example 1 was subjected to no oxidation treatment.
W ₁ and W ₂ were measured.

W ₁ = 5.0%, W ₂ = 13.0%, and the heat shrinkage was considerably large.

Comparative Example 2 W ₁ and W ₂ were measured without oxidizing the drawn yarn used in Example 2. W ₁ = 6.5% and W ₂ = 13.0%, which are almost the same as those of Comparative Example 1, indicating poor dimensional stability.

Example 3 Polyethylene terephthalate of [η] = 0.65 to which 0.5 wt% of TiO ₂ was added was extruded with a 40φ extruder, while a non-crosslinked polyphenylene sulfide having a viscosity of 2000 poise (300 ° C., 10 sec) was extruded with a 40φ extruder. After weighing each in a predetermined amount, the mixture was washed down into a spinning pack, discharged from a round hole nozzle, and a composite spinning was performed at a spinning speed of 3600 m / min. As shown in FIG. 1 (a), the cross section of the composite yarn is a complete core-sheath whose sheath is made of polyethylene terephthalate and whose core is made of polyphenylene sulfide. The composite weight ratio of polyethylene terephthalate and polyphenylene sulfide was 80:20.

The oxidation treatment was performed without stretching the spun yarn. The treatment was performed in an 81% anhydrous methanol solution of N-bromosuccinimide (NBS) at 3 ° C. for 1 hour at a bath ratio of 1:60. Processed methanol, washed with water Example 1 hot water shrinkage W ₁ was measured shrinkage in the same way as 0.6% and a dry heat shrinkage W ₂
It showed excellent thermal stability of 1.8%.

[Brief description of the drawings]

FIG. 1 is a schematic view of a spinning apparatus for obtaining a conjugate fiber of the present invention, and FIGS. 2 and 3 are cross-sectional examples showing a composite form of the fiber of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) D01F 8/14-8/16 D06M 11/32 D06M 13/418

Claims (2)

(57) [Claims] (1) Is a fiber in which a polyphenylene sulfide polymer layer (A) having a main structural unit of and a polyester layer (B) containing polyethylene terephthalate or polybutylene terephthalate as a main component, and the composite fiber has a boiling water shrinkage of 1.0% or less, Composite fiber with excellent dimensional stability, characterized in that the dry heat shrinkage at 180 ° C is 2.0% or less. (2) A fiber in which a polyphenylene sulfide polymer layer (A) having a main structural unit of and a polyester layer (B) containing polyethylene terephthalate or polybutylene terephthalate as a main component is mixed with hydrogen peroxide, an alkali metal hypochlorite, Alkaline earth metal hypochlorite, sulfuric acid, hydrochloric acid, sulfuryl chloride, nitrogen dioxide, chromium trioxide, alkali metal permanganate, nitric acid, organic peracid, lead tetraacetate, periodate, periodate, Or N-
A method for producing a conjugate fiber having excellent dimensional stability, comprising oxidizing with an oxidizing agent selected from halocarboxylic acid amides.