JPH0819571B2 - Multi-component fiber suitable for producing fine fiber bundle and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to the production of multi-component fibers capable of producing fine fiber bundles by water treatment by melt spinning.

[Conventional technology]

Conventionally, the production of a multi-component fiber composed of two or more polymers having different solubilities in a solvent and the production of a fine fiber bundle by removing the one-component polymer from the multi-component fiber is a constitution of a leather-like sheet. Many proposals have been made for use in. However, the conventional method for producing fine fibers from multi-component fibers has been mainly performed by the organic solvent treatment method.

Further, it is already known that the polyvinyl alcohol as one component is dissolved in a common solvent together with another polymer and mixed and spun by a wet method to prepare a mixed fiber, as described in JP-B-42-27268 and JP-B-41.
It is proposed in the Japanese Patent No. 3759 and others.

[Problems to be solved by the invention]

When producing a fine fiber bundle from conventional multi-component fibers, it is premised that the fine fiber phase becomes clear. For that purpose, so-called multi-component fibers have been used which have been mixed by chip mixing, melt flow mixing, etc. by the motsu-para melt spinning method or spun by forming a mixed phase by controlling at the spinneret part or the spinning head. However, in order to form fine fibers from multi-component fibers obtained by the melt spinning method, a treatment method such as dissolving a dispersion medium component with a solvent or decomposing it with a dispersant has been used. However, the solvent or decomposing agent used is an organic solvent, or a combination of a strong alkali or a strong acid or a salt thereof and an organic solvent, which not only requires enormous facilities industrially, Furthermore, a large amount of equipment is required for treating the treating agent such as the solvent after the treatment.

On the other hand, the multi-component fiber obtained by the wet spinning method using polyvinyl alcohol as one component is not in a good dispersed state like the multi-component fiber obtained by the melt spinning method, and is in a non-uniform dispersed state, or is extremely fine. In the dispersed state, fine fiber bundles having good independence cannot be obtained. Further, when trying to make the independence of the dispersion component good, when the polyvinyl alcohol that is the dispersion medium component is removed, the fiber strength of the fine fiber bundle that is the remaining dispersion component extremely decreases, and it is usually used in practice. It is difficult to obtain a non-woven fabric.

[Means for solving problems]

INDUSTRIAL APPLICABILITY The present invention uses a specific polyvinyl alcohol or modified polyvinyl alcohol capable of spinning polyvinyl alcohol or modified polyvinyl alcohol by a melt spinning method and further capable of producing a multi-component fiber by a melt spinning method together with another melt-spinning polymer. Providing multi-component fibers. Furthermore, polyvinyl alcohol or modified polyvinyl alcohol can be eluted from the multi-component fiber with water, the residual polymer component fiber forms a fine fiber bundle with good separability, and has sufficient strength that does not hinder ordinary practical use, It is another object of the present invention to provide a multi-component fiber containing polyvinyl alcohol or modified polyvinyl alcohol as a dispersion medium component, which gives a fiber product of a fine fiber bundle having a higher strength.

That is, in the present invention, the saponification degree is 50 to 98 mol%, and the relationship between the saponification degree X mol% and the polymerization degree P is log X + log.
A polyvinyl alcohol or a modified polyvinyl alcohol having P = 3.7 to 4.3 is used as a dispersion medium component, a polymer having a different solubility to a solvent from the dispersion medium component is used as a dispersion component, and the dispersion medium component and the dispersion component are composed. It is a melt-spun multi-component fiber suitable for producing a characteristic fine fiber bundle.

Further, in the present invention, the saponification degree is 50 to 98 mol%, and the relationship between the saponification degree X mol% and the polymerization degree P is log X + log P = 3.
7 to 4.3 polyvinyl alcohol or modified polyvinyl alcohol as a dispersion medium component, the dispersion medium component is different in solubility in a solvent, and is melt-spun as a dispersion component polymer having melt spinnability This is a method for producing a multi-component fiber suitable for producing a fine fiber bundle.

Polyvinyl alcohol or modified polyvinyl alcohol that is melt-spinnable and melt-spun with other melt-spinnable polymers used in the present invention has melt-spinnability and melt viscosity during spinning and water-solubility after being made into multi-component fibers. It has been found that the degree of polymerization and the degree of saponification have a great influence from the relationship of sex, and that the degree of polymerization and the degree of saponification are important to stabilize the phase of the multi-component fiber. That is, the relationship between the degree of polymerization P of the polyvinyl alcohol or modified polyvinyl alcohol used in the present invention and the degree of saponification X expressed in mol% is log X + log P = 3.7 to 4.3 in the range of the saponification degree of 50 to 98 mol%. By using polyvinyl alcohol or modified polyvinyl alcohol that satisfies this condition, multicomponent fibers can be stably spun by the melt spinning method. Alternatively, the modified polyvinyl alcohol can be dissolved and removed with water, and the strength of the fine fiber bundle of the residual polymer component is as high as 1.0 g / dr or more when measured as a fiber bundle.

Further, when the saponification degree of polyvinyl alcohol or modified polyvinyl alcohol is less than 50 mol%, the melting point is lowered but the water solubility is lowered. On the other hand, if the degree of saponification exceeds 98 mol%, the melting point and melt viscosity will rise sharply,
Even if the degree of polymerization is lowered, stable melt spinning cannot be performed. Therefore, if polyvinyl alcohol or modified polyvinyl alcohol in a range not satisfying the relational expression of log X + log P is used, a stable phase cannot be formed, stable melt spinning cannot be performed, or water solubility is deteriorated. It becomes an unfavorable state.

The polyvinyl alcohol used in the present invention has a saponification degree of 50.
~ 98 mol%, a polymer having a degree of polymerization of 400 or less,
The modified polyvinyl alcohol is a polymer having a saponification degree of 50 to 98 mol% and a polymerization degree of 400 or less, which is a water-soluble modified polyvinyl alcohol copolymerized with allyl acetate, modified by terminal paraffin modification, or modified by terminal modification.

The other melt-spinnable polymer that constitutes the multi-component fiber of the present invention is a thermoplastic polymer that does not react with polyvinyl alcohol or modified polyvinyl alcohol during melting or has low reactivity, such as polyethylene, polypropylene and polybutylene. Polyolefin or copolymerized polyolefin. Polyamides such as nylon-610, nylon-11, nylon-12, nylon-6-66, nylon-6. One or more polymers selected from polyesters such as polybutylene terephthalate, polyethylene terephthalate or copolymerized polyethylene terephthalate, polyurethane elastomers, polyester elastomers, polyamide elastomers, etc., preferably thermoplastic polymers having a melting point of 270 ° C. or less. is there.

The melt spinning method of polyvinyl alcohol or modified polyvinyl alcohol and a thermoplastic polymer is a method in which both polymers are melt mixed in the same melting system and spun. A method of spinning by melting in separate melting systems and forming a mixed flow of both polymers at the spinning head. Spinning can be carried out by any method of spinning with the disperse component and the dispersive component being regulated by the spinneret, but the latter spinning method is preferred when both polymers have reactivity when heated. The former spinning method is preferable when the number of dispersed components (the number of fine fibers) of the multi-component fiber is to be increased. In order to use polyvinyl alcohol or modified polyvinyl alcohol as a dispersion medium component in melt spinning, the polyvinyl alcohol or modified polyvinyl alcohol selected in the range of the relation log X + log P = 3.7 to 4.3, and the melt viscosity of the polymer to be combined. It is preferred to use lower melt viscosity polymers.

In the multi-component fiber of the present invention, polyvinyl alcohol or modified polyvinyl alcohol serves as a dispersion medium component (collectively includes sea component and sheath component), and other polymers collectively include a large number of dispersion components (island component and core component). ) Is a fiber that has been. When the polyvinyl alcohol or modified polyvinyl alcohol is dissolved and removed from the multi-component fiber with water, the residual polymer component fiber becomes a fine fiber bundle. In order to dissolve polyvinyl alcohol or modified polyvinyl alcohol in water, it may be treated with normal water or warm water, but in order to industrially proceed with dissolution removal, a surfactant is added to adjust the surface tension to 50 dyne / cm or less, preferably 40d
Pretreatment with water adjusted to yne / cm or less is preferable.

The multi-component fiber of the present invention is a woven fabric, knitted fabric, non-woven fabric, entangled non-woven fabric or other fibrous sheet, or a fibrous sheet obtained by containing an elastic polymer in the fibrous sheet, and then polyvinyl alcohol or modified By dissolving and removing polyvinyl alcohol, a fiber sheet or a fibrous sheet composed of fine fiber bundles can be obtained, and a bulky product and a flexible product can be obtained. When it is further made into short fibers and used in the production of paper, a paper having a good texture can be obtained. It also has a wide variety of uses such as piles for flocking, fibers for manufacturing leather-like sheets, and fibers for filters.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to examples. In the examples, "parts" and "%" relate to weight unless otherwise specified.

Example 1 Polymerization degree 110 after drying in a vacuum dryer at a temperature of 60 ° C. for 24 hours
(Log P = 2.04), saponification degree 67 mol% = (log X = 1.83)
Polyvinyl alcohol (log X + log P = 3.87) 50 parts and melt index (hereinafter MI) polypropylene 10 parts
Mix well with 50 parts in pellet form, use a screw extruder spinning machine with a diameter of 25 mm, adjust the temperature from the rear part of the spinning machine to the spinneret to 230 ° C, nozzle hole diameter 0.3 mm, number of holes 48 holes Melt spinning using the spinneret of
The discharged yarn was rapidly cooled and wound up by a cooling wind zone provided directly below the spinneret. Discharge rate 30g / min, winding speed 450m
The fiber was spun at a spinning rate of / min to obtain a multi-component fiber having a single yarn fineness of about 12 denier. As a result of observing the state of the dispersed phase by photographing the cross section of the discharge yarn of this multi-component fiber with a micrograph, the shape of a clear sea-island structure was shown, and the average number of islands in the cross section was 1200.

The wound multi-component fiber is left in a room adjusted to a temperature of 25 ° C and a humidity of 80% for 24 hours to control the humidity, and then in an air bath zone at 80 ° C.
It was stretched 2.5 times. This drawn filament was added with 0.2% of sodium oleate at room temperature water (surface strength of 28 dyne / cm
As a result of soaking for 30 minutes and then soaking in water at 30 ° C for 30 minutes and drying, the weight loss rate of the multi-component fiber was 49.3%, polyvinyl alcohol was almost dissolved and removed, and the remaining polypropylene was fine with good dispersibility. A fiber bundle was obtained. The strength of this fine fiber bundle was 2.5 g / dr.

Example 2 Polymerization degree 220 dried in a vacuum dryer at a temperature of 60 ° C. for 24 hours
(Log P = 2.34), saponification degree 71 mol% (log X = 1.85), polyvinyl alcohol (melting point 240 ° C., log X + log P = 4.1
9) and the melt flow index measured at a temperature of 250 ° C and a load of 325g
Twenty nylon-6 are separately supplied to two extruders and melted, and the die is a multi-core sheath-type multi-component fiber die with one multi-component fiber having 15 core components and a nozzle hole diameter of 0.8. m
Nylon-6 is used as the core component by using a mouthpiece with m and 10 holes.
Polyvinyl alcohol was measured as a sheath component with a gear pump, nylon-6 was supplied at 24 g / min, and polyvinyl alcohol was supplied at 8 g / min, melt-spun, and a winding speed of 150
Spinning was performed at 0 m / min to obtain a multi-component fiber having a single yarn fineness of about 19 denier.

This multi-component fiber was stretched 3 times in an air bath at 85 ° C. with humidity control and heat-set to obtain a stretched multi-component fiber of 6.1 denier. A woven fabric was made from this fiber, polyvinyl alcohol was removed in the scouring and hot-watering process at the time of dyeing to form fine fiber bundles, and then the fabric obtained by dyeing with a metal complex salt dye had a silky texture.

Example 3 Polymerization degree 110 after drying in a vacuum dryer at a temperature of 60 ° C. for 24 hours
(Log P = 2.04), saponification degree 96 mol% (log X = 1.98) allyl acetate copolymerized polyvinyl alcohol was used in place of the polyvinyl alcohol of Example 2, and spinning was carried out in the same manner as in Example 2. As a result, good results were obtained. It has spinnability and a winding speed of 1600m /
A multi-component fiber having a stable phase was obtained even when wound in minutes.

For comparison, the polymer was dried for 24 hours in a vacuum dryer at a temperature of 60 ° C for a degree of polymerization of 220 (log P = 2.34) and a degree of saponification of 98 mol% (lo).
(g X = 1.99) Allyl acetate copolymerized polyvinyl alcohol was replaced with the copolymerized polyvinyl alcohol of Example 3 and the same spinning was performed. As a result, a gel-like substance was generated to cause yarn breakage, and continuous spinning was not possible for a long time. . Furthermore, variations were found in the core component.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The present invention is capable of stably spinning a multi-component fiber using a polyvinyl alcohol or a modified polyvinyl alcohol as a dispersion medium component and another melt-spinning polymer as a dispersion component, which can easily obtain a fine fiber bundle by water treatment, by a melt spinning method. Can
Further, it is a multi-component fiber that can obtain a fine fiber bundle with good splitting property.

Claims (2)

[Claims] 1. The saponification degree is 50-98 mol%, and the relationship between the saponification degree X mol% and the polymerization degree P is log X + log P = 3.7-
4.3 is a polyvinyl alcohol or modified polyvinyl alcohol as a dispersion medium component, the dispersion medium component is a polymer having a different solubility in a solvent as a dispersion component, characterized by comprising these dispersion medium component and the dispersion component ,
A melt-spun multi-component fiber suitable for the production of fine fiber bundles. 2. The saponification degree is 50 to 98 mol%, and the relationship between the saponification degree X mol% and the polymerization degree P is log X + log P = 3.7 to
A fine fiber characterized in that polyvinyl alcohol or modified polyvinyl alcohol of 4.3 is used as a dispersion medium component, and the dispersion medium component has a different solubility in a solvent and is melt-spun with a polymer having melt spinnability as a dispersion component. A method for producing a multi-component fiber suitable for producing a bundle.