JPS6320939B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides that in the cross section of the fiber, one component A
The present invention relates to a method for producing a split polyester yarn using a split polyester composite yarn in which the other component B is divided into a plurality of pieces. More specifically, in the splittable composite yarn of the present invention, the composite component, that is, the splitting component (easily eluting component) and the splitting component (hardly eluting component) are mutually compatible polyester components, and the splitting component is a component whose hydrolysis rate by alkali is faster than that of the component to be split, and a splittable composite yarn with sufficient strength for practical use, and the splittable composite yarn is treated with an alkali to elute at least a part of the splitting component to form a polyester. The present invention relates to a method of making split yarns. [Prior art] An easily eluted component that is easily eluted in a certain solvent and a eluted component that is difficultly (or non) eluted to a certain solvent are combined into multiple eluted components that are easily eluted by the easily eluted component. By using splittable composite yarns that are arranged so as to show the shape of individual pieces, and by removing the easily eluted components with a solvent, we can create extremely fine denier yarns, especially split yarns made of difficult (or non-eluting) components of 1 denier or less. This process can be similar to the process of finishing silk fabric by removing sericin from raw silk made of sericin and fiproin, so it is widely used to create woven and knitted fabrics with silk-like wind patterns. Are known. The points that must be met when manufacturing split threads using such splittable composite threads are as follows: The difference in elution rate between easily eluting components and poorly eluting components for a certain solvent is sufficiently large, and the elution rate of easily eluting components is fast. thing. The elution equipment, operation, and solvent are not special.
It should be safe and inexpensive without being corrosive to the elution device. The constituent ingredients are not special and are inexpensive. Stable processing is possible without problems such as peeling between easily eluted components and difficult (or non-eluted) components in the processes leading up to the final product, such as spinning, stretching, weaving, knitting and weaving, before elution treatment. It must have sufficient strength for practical use in weaving and weaving processes and knitted fabrics. Here, the difficult (or non-) eluting components are divided into polyethylene terephthalate, which has excellent physical properties such as high melting point, high strength, high Young's modulus, good electrical properties, and chemical resistance, and is made into a final product. As a type composite yarn, it is used as an easily eluting component.
Those using polystyrene, nylon 6, etc. are widely known, as disclosed in Japanese Patent Application Laid-open No. 42847 and Japanese Patent Application Laid-open No. 48-9021. However, the removal of such easily leached components requires the use of specific organic solvents or strong acids, which is unsatisfactory in terms of safety and cost, and furthermore, in the case of nylon 6, there is a drawback that flaking tends to occur. The following examples are known in which a polyester is used as a poorly eluted component, a polyester having good compatibility with the polyester is used as an easily leached component, and the easily leached component is removed by a simple alkali aqueous solution treatment. In the examples of Japanese Patent Publication No. 39-29636, an example is described in which polyethylene terephthalate is used as a hardly eluting component and a copolymer of polyethylene terephthalate and polyethylene oxide glycol is used as an easily eluting component. However, when such a copolymer is used, unless a large amount of polyethylene oxide glycol is copolymerized, the easily eluted components cannot be completely eluted, and if a large amount is used, the spinning property is deteriorated. As a solution to this drawback, Japanese Patent Publication No. 47532 and Japanese Patent Publication No. 47-47-
No. 47533 proposes using polyethylene terephthalate as a poorly eluting component and adding specific polyalkylene glycols or anionic surfactants to polyethylene terephthalate as an easily eluting component, but the present inventors A detailed study revealed that it was difficult to make the additives uniformly exist in the length direction of the easily eluted components in the splittable composite yarns, and that the elution treatment was used to prevent uneven splitting in the lengthwise direction of the splittable composite yarns. It has been found that there are some drawbacks that are likely to occur. Furthermore, Japanese Patent Publication No. 48-33415 describes alkali-soluble polyester (polyethylene glycol or polypropylene glycol) as an easily leached component.
Examples are given of copolymers or blends, polyethylene sebacate, polyethylene adipate, di- or triethylene glycol terephthalate or polyethylene terephthalate copolymers, and copolymer polyesters consisting of polyethylene glycol/polypropylene glycol, but these are merely general examples. Either the polyester polymer is merely a list of polyester polymers, it cannot actually withstand melt spinning for a long time, or it has the disadvantage of easily causing uneven splitting like the additive method described above. It is something that you have. [Problems to be Solved by the Invention] The present invention has been achieved as a result of intensive studies to eliminate the drawbacks of the prior art. In other words, the present invention eliminates peeling between easily eluted components and poorly eluted components before elution processing such as stretching, knitting and weaving, and eliminates the eluted components by using dilute alkali treatment, which is a simple elution process, without eluting most of the hardly eluted components. Provided is a method for producing split polyester yarn by alkali treatment using a split type polyester composite yarn that can be completely eluted without causing uneven splitting in the length direction of the yarn, and has sufficient strength for practical use. It is something to do. [Means for Solving the Problems] That is, the present invention involves treating a split-type composite yarn in which one component A is divided into a plurality of pieces of the other component B with an alkaline aqueous solution to elute at least a portion of one component A. When forming a split yarn, one component A of the split type composite yarn is ethylene 5, which accounts for 3 mol% or more of the total structural units.
- sodium sulfoisophthalate, and
80 mol% or more is ethylene terephthalate Intrinsic viscosity (in orthochlorophenol at 25°C) is 0.60
The following polyester is used, the other component B is a polyester in which 80 mol% or more is ethylene terephthalate, the constitutional unit is 1 denier or less, and the intrinsic viscosity is in the range of 0.50 to 0.80, and one component This is a method for producing split polyester yarn, characterized in that the composite yarn is obtained by split-type composite spinning using polyester having a viscosity 0.05 or more higher than the viscosity. The yarn cross-sectional shape of the split yarn obtained in the present invention is
FIG. 2 schematically shows the cross-sectional shape of the splittable composite yarn used to obtain this splitted yarn. In FIGS. 1 and 2, A is an easily eluted component and B is a poorly eluted component. In Figure 2 a, b, and c, in the round cross section, the slightly eluted components are 2, 3, and 6 %, respectively, due to the easily leached components.
It is divided into. When these splittable composite threads are treated with an alkali to remove the easily eluted component A, splittable threads having the shapes as shown in FIG. 1a, b, and c are obtained. Figure 2 d shows a sea-island type split composite yarn in which the easily eluted component is the sea and the poorly eluted component is the island. After being treated with an alkali to remove easily eluted components, it becomes 14 denier-mixed split threads of approximately 7 sizes each, as shown in Figure 1(d). The splittable composite yarns shown in Figures 2 a to d have circular cross sections, whereas Figures 2 e and f have irregular cross sections, and the poorly eluted component B is divided into 3 or 4 parts by the easily leached component A. Then, when the easily eluted components are removed by alkali treatment, split threads having the shapes as shown in FIG. 1e and f are obtained, respectively. In the present invention, in the splittable polyester composite yarn for obtaining such a split polyester yarn, one component, that is, the easily leached component A, is ethylene 5-sodium sulfoisophthalate, which accounts for 3 mol% or more of the total structural units, and 80 mol%. The above is characterized in that it is a polyester having an intrinsic viscosity of 0.60 or less, which is ethylene terephthalate. Ethylene 5-sodium sulfoisophthalate and ethylene terephthalate copolymer polyester was treated with alkali (alkali aqueous solution concentration NaOH20
Table 1 shows the change in weight loss rate with respect to the amount of ethylene 5-sodium sulfoisophthalate.

[Table] In Table 1, as the amount of ethylene 5-sodium sulfoisophthalate increases, the weight loss rate due to alkali treatment increases, and surprisingly, 3
The weight loss rate increases rapidly after reaching around mol%.
Furthermore, Table 2 shows that polyethylene terephthalate is used as the poorly eluted component, and the composite ratio of the easily leached component of the splittable composite yarn having the cross section as shown in FIG. 2b is 25% of the total.
A copolymer of ethylene terephthalate with varying amounts of ethylene 5-sodium sulfoisophthalate is used as the eluted component, and alkali treatment is performed until the splitting of the resulting splittable composite yarn is completed.
The weight loss rate at that time was determined.

〔Example〕

The present invention will be specifically explained below with reference to Examples. Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.68 as a poorly eluting component, and ethylene 5- as an easily eluting component.
Polyethylene terephthalate (intrinsic viscosity
0.50) was spun using the composite spinning apparatus shown in Japanese Patent Publication No. 47-2485 as shown in Figure 3 at a spinning temperature of 290°C and a spinning speed of 1050 m/min to produce a split type composite having a cross section as shown in Figure 2 c. Got the thread. In this splittable composite yarn, the easily eluted component accounts for 20 wt% of the total. Continue stretching speed 300
Normal drawing was carried out at m/min, hot pin 100℃, and draw ratio 3.4 times to form 50 denier 12 filaments (the constituent unit fineness of the drawn yarn was 0.56 denier, and after splitting
72 filaments) was made into a drawn yarn. This drawn yarn was used as a warp yarn and a weft yarn, and a plain woven fabric was woven at a density of 115 yarns/2.54 cm.
This fabric was scoured with Neugen and soda ash in water at 98-100°C, and then fixed in shape by dry heat setting at 180°C for 3 minutes while allowing free shrinkage. Next, the easily eluted components were completely eluted by alkaline treatment with 30 g/aqueous sodium hydroxide solution at 98 to 100 DEG C. for 40 minutes, followed by washing with water and air drying. The resulting fabric was heated in a substantially tension-free state at 165
Dry heat finish setting was performed for 3 minutes at ℃. The obtained fabric was a silk-like fabric with excellent drapability, bulkiness, and soft touch and texture. Example 2 Polyethylene terephthalate with an intrinsic viscosity of 0.70 as a poorly leached component, and ethylene 5-sodium sulfoisophthalate/ethylene terephthalate (5 mol%/95 mol%) copolymer with various intrinsic viscosities shown in Table 3 as an easily leached component. According to Example 1, the second
A composite yarn having a cross section as shown in Figure e was obtained. Subsequently, drawing was carried out in the same manner as in Example 1 except that the drawing ratio was changed as shown in Table 3, and the drawn yarn (cut and stretched degree 30
%). As shown in Table 3, the strength of the drawn yarn decreases as the intrinsic viscosity of the easily eluted component increases, and when the intrinsic viscosity is greater than 0.60, it is difficult to handle it as a normal polyester fiber.

[Table] Also, during drawing of No. 6, there were many single thread breaks and the drawing properties were poor. Using drawn yarns No. 2 to 6, weaving, heat setting, alkali treatment, and finishing setting were performed according to Example 1. The obtained fabric was a silk-like fabric with excellent drapability, bulkiness, and soft touch and texture. However, compared to Nos. 2 to 5, No. 6 had more thread breakage during weaving, more fuzz was produced in the fabric, was less resistant to tearing, and was poor in both quality and practicality. Example 3 Polyethylene terephthalate with various intrinsic viscosities shown in Table 4 as a poorly leached component, and ethylene 5-sodium sulfoisophthalate/ethylene terephthalate (5 mol%/95 mol%) copolymer with an intrinsic viscosity of 0.58 as an easily leached component. According to Example 1, the second
A composite yarn having a cross section as shown in FIG. 6 was obtained. Example 1 except that the stretching ratio was changed as shown in Table 4.
The drawn yarn (cutting elongation 30
%). As shown in Table 4, the strength after stretching decreases as the intrinsic viscosity of the poorly eluted component is lowered to approach that of the easily eluted component. This indicates that unless the intrinsic viscosity of the poorly eluted component is 0.05 or more greater than the intrinsic viscosity of the easily eluted component, it is difficult to handle it as a normal polyester fiber.

〔Effect of the invention〕

According to the splittable yarn manufacturing method of the present invention, the splittable composite yarn is easy to handle before splitting, the splitting process can be performed extremely quickly and without uneven splitting, and the weaving process and It has sufficient strength for practical use in knitting fabrics, and after splitting, it is possible to obtain ultra-fine split yarns of 1 denier or less or ultra-fine split yarns with irregular cross sections. Using ordinary spinning and drawing methods to obtain ultrafine yarns of 1 denier or less not only has the drawback of easily causing problems such as yarn breakage and fluffing during the spinning and drawing processes, but also has similar problems in higher-order processes such as weaving, knitting, and weaving. There's a problem. On the other hand, by designing the composite yarn so that the denier is greater than 1 denier and the composite yarn is divided into ultrafine divided yarns of 1 denier or less after division, it can stably pass through the spinning, drawing, knitting and weaving processes. Therefore, it can be applied to the production of suede-like knitted fabrics made of ultra-fine yarns or silk-like knitted fabrics with an elegant luster and soft texture, and can also be used for heating, sizing, etc. by taking advantage of the ease of handling during the weaving process. It can be applied to warp yarns without performing convergence processing similar to these. In addition, in the method for producing split polyester yarn according to the present invention, the elution of easily eluted components during alkali treatment is extremely rapid, and the elution of poorly eluted components is extremely small, and the effect of the treatment time after the elution of easily eluted components is small and stable. It has the characteristic that it can be treated with alkali.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of various split yarns obtained by the present invention, FIG. 2 is a cross-sectional view of various split-type composite yarns for obtaining the split yarns of the present invention, and FIG. 3 is a cross-sectional view of various split yarns of the present invention. 1 is a schematic cross-sectional view of the vicinity of a discharge hole showing a spinning state of a split type composite yarn for obtaining a yarn. A: Easily eluted component, B: Difficultly eluted component.

Claims (1)

[Claims] 1 When treating a splittable composite yarn in which one component A is divided into a plurality of pieces of the other component B with an alkaline aqueous solution to elute at least a portion of one component A and make the split yarn, one component A of the split composite yarn is using a polyester with an intrinsic viscosity (in orthochlorophenol at 25°C) of 0.60 or less, in which 3 mol% or more of the total structural units is ethylene 5-sodium sulfoisophthalate, and 80 mol% or more is ethylene terephthalate, On the other hand, component B is a polyester in which 80 mol% or more is ethylene terephthalate, the constitutional unit is 1 denier or less, and the intrinsic viscosity is 0.50 to
A method for producing split polyester yarn, characterized in that the composite yarn is obtained by split-type composite spinning using a polyester having an intrinsic viscosity of 0.80 and 0.05 or more higher than the intrinsic viscosity of component A.