JP2006274470A - Method for producing polyvinyl chloride-based fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably producing polyvinyl chloride-based fiber hardly causing troubles due to fiber cut. <P>SOLUTION: The method for producing polyvinyl chloride-based fiber comprises using a single shaft extruder with a screw of 1.1-2.0 compression ratio when producing fiber by melt-spinning a resin composition composed mainly of polyvinyl chloride-based resin. Preferably, at least one of following (1) to (3) embodiments is included. (1) Melt-spinning uses a full-flight screw having a 2-5 angles cross section in the spiral direction of the screw. (2) Melt-spinning uses a screen mesh having ≤80 μm aperture. (3) The resin composition composed mainly of polyvinyl chloride-based resin contains 0.2-5 pts.mass inorganic stabilizer selected from hydrotalcite and zeolite. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for producing a vinyl chloride fiber. Units such as “parts” indicating the composition of a resin composition mainly composed of a vinyl chloride resin (hereinafter abbreviated as “vinyl chloride resin composition”) are expressed on a mass basis unless otherwise specified. .

Since vinyl chloride fiber obtained by spinning a vinyl chloride resin composition is excellent in transparency and flexibility, it is often used, for example, as a fiber for artificial hair constituting a hair ornament product. In order to industrially produce this artificial hair fiber, there are a wet spinning method, a dry spinning method in which a vinyl chloride resin composition is spun using an organic solvent, and a melt spinning method in which melt spinning is carried out without using an organic solvent. Are known.

The melt spinning method is a method of extruding a resin at a high temperature and high pressure using an extruder, and this spinning method is generally used at present in a vinyl chloride resin composition. However, with vinyl chloride resin alone, thermal decomposition of the resin starts near the molding temperature, and unlike solution spinning, it is necessary to blend a large amount of additives such as stabilizers and lubricants. There is a problem that single yarn breakage tends to occur. This single yarn breakage is intricately intertwined with various factors such as the molten state of the PVC resin composition, the nozzle hole tip state, the strand outflow state, and the state of the undrawn yarn swimming from the nozzle tip to the take-up roll. It is thought that it is not analyzed enough. In order to solve this problem, a means has been proposed in which a uniform melt state is created and the single yarn breakage is improved by increasing the compression ratio of the screw (for example, Patent Document 1).
JP 2000-328353 A

An object of the present invention is to easily produce a vinyl chloride fiber with few single yarn breaks.

As a result of intensive studies to achieve the object, the present inventor has found that the compression ratio of the screw is the most important factor, and has completed the present invention.

The present invention uses a single screw extruder and a screw having a compression ratio of 1.1 to 2.0 when a fiber is produced by melt spinning a resin composition mainly composed of a vinyl chloride resin. This is a method for producing a spun vinyl chloride fiber.

In the present invention, at least one selected from the following embodiments (1) to (3) is preferably provided. (1) Melt spinning using a full flight screw whose cross-sectional shape in the spiral direction of the screw is 2 to 5 angles. (2) Melt spinning using a screen mesh having an opening of 80 μm or less. (3) The resin composition mainly composed of vinyl chloride resin contains 0.2 to 5 parts by mass of an inorganic thermal stabilizer selected from hydrotalcite and zeolite.

The object of the present invention is:
According to the present invention, a vinyl chloride fiber with few single yarn breaks can be easily produced.

The vinyl chloride resin used in the present invention is obtained by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., and is manufactured by suspension polymerization in consideration of the initial colorability of the fiber. It is preferable to use what has been prepared. The vinyl chloride resin is a homopolymer resin, which is a conventionally known homopolymer of vinyl chloride, or various conventionally known copolymer resins, and is not particularly limited. As the copolymer resin, conventionally known copolymer resins can be used, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl propionate copolymer resins, and other vinyl chloride-vinyl ester copolymer resins, vinyl chloride-butyl acrylate copolymers. Resins, copolymer resins of vinyl chloride and acrylates such as vinyl chloride-2-ethylhexyl acrylate copolymer resin, copolymer resins of vinyl chloride and olefins such as vinyl chloride-ethylene copolymer resin, vinyl chloride-propylene copolymer resin, Representative examples include vinyl chloride-acrylonitrile copolymer resins. It is particularly preferable to use a homopolymer resin, a vinyl chloride-ethylene copolymer resin, a vinyl chloride-vinyl acetate copolymer resin, or the like, which is a homopolymer of vinyl chloride. In the copolymer resin, the content of the comonomer is not particularly limited, and can be determined according to required qualities such as moldability and yarn characteristics.

The viscosity average polymerization degree of the vinyl chloride resin is preferably 600 to 2500. If it is less than 600, the resulting melt viscosity tends to cause heat shrinkage. On the other hand, when it exceeds 2500, the melt viscosity increases, the molding temperature increases, and the fiber may be colored. The viscosity average degree of polymerization is calculated according to JIS-K6721 by dissolving 200 g of resin in 50 ml of nitrobenzene, measuring the specific viscosity of this polymer solution in a constant temperature bath at 30 ° C. using an Ubbelohde viscometer.

The vinyl chloride fiber melt extruder of the present invention means an extruder used for melt spinning, and a single-screw extruder is preferably used for production. If a conventionally known different-direction twin-screw extruder, same-direction twin-screw extruder, conical extruder or the like is used, single yarn breakage is increased, which is not preferable. The twin-screw extruder is presumed to have a greater kneading effect and less single yarn breakage, but surprisingly the single-screw extruder has less single yarn breakage. Generally, in a twin-screw extruder, the clearance between the screw and the barrel (cylinder inner wall) is small, and even if the injected PVC resin composition is insufficiently kneaded or poorly uniform, it is quantitatively extruded. Therefore, it is considered that single yarn breakage is likely to occur. On the other hand, in the case of a single-screw extruder, the clearance is relatively large, and a backflow is generated to bring about a uniform kneading state.

In the present invention, the compression ratio of the screw is preferably 1.1 to 2.0 in a single-screw extruder, and troubles due to single yarn breakage can be reduced and stable production can be achieved. When the compression ratio is less than 1.1, the vinyl resin composition is not sufficiently melted, the molten state becomes non-uniform, and single yarn breakage occurs frequently. On the other hand, if the compression ratio is larger than 2.0, the resin temperature of the molten resin rises, and the deterioration of the molten resin is promoted, so that it cannot be stably produced. Therefore, in order to bring about a uniform molten state, the region of 1.1 to 2.0 is preferable, and 1.2 to 1.8 is more preferable.

Also, on the outer peripheral surface of the kneading part formed in the maximum outer diameter dimension of the screw in the single screw extruder, the central part in the spiral direction is the deepest groove depth, and the groove shallower as the distance from this central part to the front and rear side in the spiral direction The cross-sectional shape of the screw in the spiral direction is preferably from 2 to 5 (2, 3, 4, 5), with the multiple kneading recesses being eccentric from the axial center of the screw. It can be manufactured stably with fewer breaks. If the number is less than two, the shear stress is small, and the resin cannot be melted uniformly and sufficiently, so that single yarn breakage may occur frequently. Moreover, if it is a hexagon, excessive heat generation may occur. Preferably, since the excessive heat generation of the resin can be easily suppressed, the cross-sectional shape of the screw in the spiral direction is preferably a square. Moreover, it is preferable that the type of a screw is a full flight type screw of a single thread screw or a double thread. If a dalmage-type screw, a screw with a pin, or the like is used, the resin temperature rises and the long run property may be deteriorated.

Further, the screen in the present invention means a wire mesh used for sieving powder, and it is preferable to be able to remove foreign matter mixed in, or to have a shearing effect, and in the present invention, A screen mesh having an opening of 80 μm or less is preferable.

The screen mesh is preferably used by fixing it to the breaker plate at the tip of the screw during melt spinning, preventing the resin or additive mass that has not been sufficiently melted in the screw from passing through, and the resin in a uniform molten state. In addition, it is possible to increase the back pressure in the cylinder and increase the resin kneading effect. If the mesh of the screen mesh is larger than 80 μm, the molten state of the resin becomes non-uniform and single yarn breakage may occur frequently.

As the material for the screen mesh, conventionally known materials can be used, but those having the property of not being corroded by the PVC-based resin composition to be melt-molded, or materials that can withstand the high pressure applied from the extruder are preferable. Stainless steel and the like are particularly preferable.

In the present invention, the vinyl chloride resin composition preferably contains 0.2 to 5 parts by mass of an inorganic thermal stabilizer selected from hydrotalcite and zeolite with respect to 100 parts by mass of the vinyl chloride resin. More preferably, 0.4-3 mass parts is good. If the blending amount of the inorganic thermal stabilizer selected from hydrotalcite and zeolite is less than 0.2 parts by mass, the frequency of single yarn breakage increases, and if it is more than 5 parts by mass, the transparency may deteriorate. is there.

In the vinyl chloride fiber in the present invention, a lubricant can be used depending on the purpose. As the lubricant that can be used, conventionally known lubricants can be used, and in particular, one or a mixture of two or more selected from metal soap lubricants, higher fatty acid lubricants, and polyethylene lubricants may be used.

Examples of the metal soap lubricant include metal soaps such as stearates such as Na, Ca, Zn, Ba and Mg, laurates and oleates. Examples of the higher fatty acid lubricant include hardened oil, butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, stearyl stearate, alcohol, fatty acid ester of polyhydric alcohol, and the like. The polyethylene lubricant is not particularly limited, and a conventionally known lubricant can be used. Particularly preferred is a high density polyethylene lubricant having an average molecular weight of 2000 to 6000 and a density of 0.95 to 0.98.

In the present invention, known compounding agents, for example, processing aids, reinforcing agents, ultraviolet absorbers, antioxidants, plasticizers, antistatic agents, fillers, flame retardants, pigments, etc., are used depending on the purpose. Can do. Moreover, special compounding agents such as a foaming agent, a crosslinking agent, a tackifier, a hydrophilicity imparting agent, a conductivity imparting agent, and a fragrance can be added as necessary within a range not inhibiting the effects of the present invention.

The vinyl chloride resin composition used in the present invention is a powder compound obtained by mixing using a conventionally known mixer such as a Henschel mixer, a super mixer, a ribbon blender, etc., for example, a pellet compound obtained by melt-mixing this. Can be used as The powder compound can be produced under conventional conditions known in the art and may be hot blend or cold blend, but particularly preferably, the cut temperature during blending is set to 105 to 155 in order to reduce the volatile content in the composition. It is preferable to use a hot blend that is raised to 0 ° C. The pellet compound can be produced in the same manner as in the production of a normal vinyl chloride-based pellet compound. For example, pellets using a kneader such as a single screw extruder, a different direction twin screw extruder, a conical twin screw extruder, a same direction twin screw extruder, a kneader, a planetary gear extruder, a roll kneader, etc. It can be a compound. The conditions for producing the pellet compound are not particularly limited, but it is desirable to set the resin temperature to be 185 ° C. or lower.

In the present invention, the temperature condition at the time of melt spinning the vinyl resin composition is not determined by melt spinning the pellet compound of the vinyl resin composition at a temperature of 170 to 190 ° C. using a single screw extruder. A drawn yarn is obtained. As the stretching treatment conditions, the unstretched yarn was stretched 2 to 4 times in an air atmosphere maintained at a temperature of 90 to 120 ° C, and then the stretched vinyl chloride fiber was maintained at a temperature of 110 to 140 ° C. Thermal relaxation is performed in an atmosphere until the length reaches 60 to 100% before annealing.

The cross-sectional shape of the vinyl chloride fiber of the present invention may be any shape, for example, circular, oval, glasses, star, H, T, Y, triangle, quadrangle, cross, heart, horseshoe, A bowl shape or a combination thereof may be used. Moreover, these hollow bodies may be sufficient.

The thickness of the vinyl chloride fiber of the present invention is preferably 20 to 100 denier, more preferably 50 to 80 denier. If the thickness of one vinyl chloride fiber is 20 to 100 denier, it will not be inferior to natural hair, and if it is 50 to 80 denier, the feel and texture will be further improved.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples.

In Table 1, “single yarn breakage frequency” was determined by measuring the number of occurrences of single yarn breakage by simultaneously melt-spinning 120 undrawn yarns from a spinning mold for 30 minutes. From the total number of occurrences when this measurement was performed three times, the following criteria were used for evaluation.
Excellent Single yarn breakage is zero, and there is no problem at all for long run production.
Good 1 to 2 times, no problem for long run production.
Defects 3 times or more, and there is a problem as a long run manufacturing target.

In Table 1, “resin pressure” is an index of whether spinning can be performed in a stable state for a long time when continuous spinning is performed. In the measurement method of the resin pressure, the resin pressure at the screw tip when continuously spinning for 24 hours was measured and evaluated according to the following criteria.
Excellent The resin pressure is 30 MPa or less, and there is no problem as a long run production target. Good 30 to 40 MPa, no problem for long run production.
Defect 40 MPa or more, there is a problem as a long run manufacturing object.

In Table 1, “resin temperature” is an index indicating whether spinning can be performed in a stable state for a long time when continuous spinning is performed. In the measurement method of the resin temperature, the resin temperature at the screw tip when continuously spinning for 24 hours was measured and evaluated according to the following criteria.
Excellent The resin temperature is 175 ° C. or lower, and there is no problem as a long run production target. Good It is 175-185 degreeC, Comprising: There is no problem as a long run manufacturing object.
Defect It is 185 ° C. or higher, and there is a problem as a long run production target.

(Example 1) 100 parts by mass of a vinyl chloride resin (TH-1000 manufactured by Taiyo PVC Co., Ltd.), 3 parts by mass of a hydrotalcite-based composite stabilizer (CP-410A manufactured by Nissan Chemical Industries, Ltd.), epoxidized soybean oil (Asahi Denki Kogyo Co., Ltd. O-130P) 0.5 parts by weight of an ester lubricant (EW-100 manufactured by Riken Vitamin Co., Ltd.) 0.8 parts by weight of a vinyl resin resin composition is a full-flight screw with a single thread. The screw compression ratio is 1.2, the screw cross-sectional shape is the double screw shown in FIG. 1, a screen mesh with a mesh opening of 75 μm, a nozzle cross-sectional area of 0.06 mm 2, a hole number of 120, and a mold temperature of 170 ° C. A vinyl chloride resin composition was extruded from a spinning die at an extrusion rate of 10 kg / hour, and melt-spun to an average fineness of 180 denier. Further, the fiber obtained by melt spinning is stretched to 300% in an air atmosphere at 105 ° C., and the entire length of the fiber is shrunk to 75% before treatment in an air atmosphere at 110 ° C. Heat treatment was performed to obtain a vinyl chloride fiber having an average fineness of 60 denier.

(Example 2) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that a screen mesh having an opening of 90 µm was used.

(Example 3) The compression ratio of the screw is 1.8, the cross-sectional shape of the screw is the three corners of FIG. 2, and the hydrotalcite-based composite stabilizer is a zeolitic stabilizer (SP # 2300 manufactured by Nitto Flour Industry Co., Ltd.) 0 A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the amount was changed to 0.5 parts by mass.

(Example 4) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the cross-sectional shape of the screw was made circular as shown in FIG.

(Example 5) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the compression ratio of the screw was 1.8 and the cross-sectional shape of the screw was the hexagon of FIG.

(Comparative Example 1) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the compression ratio of the screw was 1.0 and the cross-sectional shape of the screw was the two corners of FIG.

(Comparative Example 2) A vinyl chloride fiber was obtained in the same manner as in Example 3 except that the compression ratio of the screw was 2.5 and the cross-sectional shape of the screw was the two corners of FIG.

(Comparative Example 3) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the compression ratio of the screw was 1.0 and the cross-sectional shape of the screw was the circle shown in FIG.

(Comparative Example 4) A vinyl chloride fiber was obtained in the same manner as in Example 1 except that the compression ratio of the screw was 2.5 and the cross-sectional shape of the screw was the circle shown in FIG.

As is clear from the comparison between Examples and Comparative Examples, according to the production method of the present invention, there were few troubles due to single yarn breakage, vinyl chloride fibers were stably produced, and productivity was remarkably excellent.

The vinyl chloride fiber produced according to the present invention can be suitably used, for example, for artificial hair.

It is a schematic sectional drawing of the screw whose cross-sectional shape is a square. It is a schematic sectional drawing of the screw whose cross-sectional shape is a triangle. It is a schematic sectional drawing of the screw whose cross-sectional shape is a hexagon. It is a schematic sectional drawing of a screw with a circular cross-sectional shape.

Explanation of symbols

1 Flight Land 2 Kneading recess

Claims (4)

When producing a fiber by melt spinning a resin composition mainly composed of a vinyl chloride resin, the fiber composition was melt spun using a single screw extruder and a screw having a compression ratio of 1.1 to 2.0. A method for producing a vinyl chloride fiber. The method for producing a vinyl chloride fiber according to claim 1, wherein the screw is melt spun using a full flight screw having a cross-sectional shape in the spiral direction of 2 to 5 squares. The method for producing a vinyl chloride fiber according to claim 1 or 2, wherein when a fiber composition is produced by melt spinning a resin composition mainly composed of a vinyl chloride resin, the fiber composition is melt spun using a screen mesh having an opening of 80 µm or less. The resin composition mainly composed of a vinyl chloride resin contains 0.2 to 5 parts by mass of an inorganic thermal stabilizer selected from hydrotalcite and zeolite with respect to 100 parts by mass of the vinyl chloride resin. The manufacturing method of the vinyl chloride fiber of any one of -3.