JPH01118618A - Method for melt spinning - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the production of a composite fiber having an island structure having irregularly shaped islands. Furthermore, the present invention is disclosed in Japanese Patent Publication No. 53-880.
6, No. 53-8807, No. 5.3-8808, No. 53-8809, and No. 58-51043 to produce composite fibers with a sea-island structure having irregularly shaped islands. This relates to melt spinning.

[Conventional technology]

Conventionally, as a method for producing composite fibers having a sea-island structure, methods for determining the shape of a sea-island structure or an island structure by controlling the spinneret part of a spinning device, such as Japanese Patent Publication No. 46-3817 and Japanese Patent Publication No. 46-26895, have been proposed. Official Gazette, Special Publication No. 58-12
This method has been proposed in Japanese Patent Publication No. 366, Japanese Patent Publication No. 60-28922, Japanese Patent Publication No. 52202-1987, and the like. Also,
The two types of polymer streams are combined at the spinning head of the spinning device,
A method of repeatedly dividing and integrating liquid streams to produce composite fibers with a sea-island structure in which one part is a sea component and the other part is an island component is described in, for example, Japanese Patent Publication No. 47-15526 and Japanese Patent Publication No. 47-1553.
Publication No. 0, Special Publication No. 47-15532, Special Publication No. 1977
-15535, or JP 53-8806, JP 53-8807, JP 53-88
Publication No. 08, Special Publication No. 1988-8809, Special Publication No. 1988
This was proposed in Publication No.-51043.

[Problem that the invention seeks to solve]

In the conventional method of producing sea-island structure composite fibers in the form of long elliptic islands, the method of controlling the island shape with the spinneret structure has its limits, and if there are more than a few dozen islands, it will be difficult to agglomerate or control the island shape.
Fusion occurs and composite fibers with a good sea-island structure cannot be obtained. In order to create a sea-island structure by combining two types of polymer flows at the spinning head and repeating division and integration of the liquid flows, the melt viscosity ratio of the polymers must be increased, and the polymers forming the island components must have different cohesive energies. A good sea-island structure cannot be formed unless a large number of sea-island structures are combined. In such a case, the island shape becomes circular, and it is difficult to stably form an oblong island shape. In addition, a spinning method in which two types of polymer streams are merged at the spinning head and the liquid stream is divided multiple times to form a sea-island structure can also stably form long elliptical island shapes, producing composite fibers with a sea-island structure. It is possible to obtain this in a place with a small number of high fibers, but if the high fiber density is increased to more than a few dozen islands, agglomeration and fusion of the high fibers occur, making it impossible to obtain composite fibers with a good sea-island structure. Particularly when the volume fraction of the island component is in a range of 50 coefficients or more, aggregation and fusion become remarkable.

The present invention combines two types of polymer streams at a spinning head,
When producing composite fibers with a sea-island structure by repeating the splitting of a liquid stream multiple times, even if the number of island components is increased, the occurrence of agglomeration and fusion can be prevented or suppressed, and the sea-island structure of the elongated island components can be prevented or suppressed. The aim is to stably produce structural composite fibers. Furthermore, it has become possible to adjust the ratio of the major axis to the minor axis of the oblong ellipsoidal island shape. Furthermore, it is an object of the present invention to provide an effective method for reproducing the core shape or island shape through the internal nozzle hole shape of the spinneret device in other island-shaped composite spinning methods.

[Means for solving problems]

The present invention involves melting two types of polymers with different melt flow characteristics in separate melt systems to form a melt flow, joining the two types of polymer flows to form a joint flow,
When producing a conjugate fiber having a sea-island structure with an elongated island shape in the cross section of the fiber by repeating the splitting of the joint flow multiple times, an additive that reduces the interfacial tension between the polymers is blended into one of the polymers. This is a melt spinning method characterized by the following.

That is, in the present invention, two types of polymer flows having different melting properties are merged at a spinning head to form a combined flow, and the combined flow is divided multiple times to form at least 15 oblong island components, preferably at least 15 islands. In order to produce a composite fiber with a sea-island structure having a large number of islands of 25 or more, additives that reduce the interfacial tension between the molten polymers are added to either one of the two types of polymers or to all of the polymers if necessary. blending to reduce the interfacial tension between the molten polymers.

The preferable interfacial tension is that the interfacial tension is reduced by 5 dyne/cm or more by adding additives during melt bonding, and the interfacial tension is 10 dyne/cm or less, preferably 7 dyne/C11 or less. . If the decrease in interfacial tension is small and exceeds the l Q dyne radius, it becomes difficult to cause fusion when increasing the number of layers or to increase the ratio of the major axis to the short axis of the oblong ellipse. Reducing the interfacial tension does not mean that even if the number of particles is increased, the occurrence of fusion can be prevented or suppressed, but it becomes possible to change the ratio of the major axis to the minor axis of the oblong ellipse. Furthermore, even in a composite spinning method in which the island shape is regulated by the internal nozzle shape of the spinneret device, the island shape can be formed through the internal nozzle shape.

The additives added to the polymer in the present invention need to be substances that have no significant effect on the polymer in a molten state. A block copolymer of both polymers can be used as such an additive, but a block copolymer of both polymers can be used as an additive that has good affinity with many molten polybodies and is highly effective in reducing interfacial tension. It uses polymerized thermoplastic polyvinyl alcohol.

The amount of the additive to be used is determined in consideration of various properties such as the properties of the molten polymer and the interaction between the molten polymers, but is generally 5 to 50% by weight based on the total molten polymer. Alternatively, the entire amount of the sea component polymer may be replaced with an additive.

Furthermore, the polymer for producing the sea-island structure composite fiber of the present invention is a thermoplastic polyester having melt flowability. − is sufficient;
For example, polyester obtained by condensation polymerization of dicarboxylic acid and diol, polyamide 1 obtained by ring-opening polymerization of lactam or condensation polymerization of dicarboxylic acid and diamine, polyolefin or olefin copolymer obtained by polymerization of olefin, polycarbonate, polystyrene or styrene. copolymer,
Two types of polymers having different melt flow characteristics selected from polyvinyl alcohol or vinyl alcohol copolymer, polyvinyl chloride, polyurethane, polyester elastomer, polyamide elastomer, etc. are used. In addition, in the method of using fibers in which the sea component that constitutes the I fibers is removed and island component fibers are used to make composite fibers with a sea-island structure into leather-like sheets or highly dense fabrics, the fibers are sufficient as island component polymers. The key is to choose a polymer that can provide performance. For example, polyester, polyamide, polyolefin, polyurethane, polyester elastomer, polyamide elastomer, polyvinyl chloride, etc. are suitable. On the other hand, sea components that are removed in the final product include, for example, polyolefin or olefin copolymer, polystyrene or styrene copolymer, polyvinyl alcohol or vinyl alcohol copolymer, polyester, etc. treated with a solvent or decomposition agent. It is a polymer that can be easily removed by

The sea-island structure composite fiber of oblong islands obtained in the present invention can be used as it is as fabrics such as woven fabrics, knitted fabrics, or non-woven fabrics. A non-woven fabric for 7-aging products with good texture and flexibility can be obtained. It can be made into a fabric and thermally calendered to make a strong and flexible sheet containing fine fibers. In addition, by using it as a base material fiber that constitutes a leather-like sheet,
For example, a raised suede-like sheet or pile fabric having anisotropy in gloss can be obtained.

Next, FIG. 1 shows a schematic diagram of a composite fiber having an oblong island-shaped sea-island structure according to the present invention. 1 is an oblong island component, 2
is the sea component. Fig. fs2 is a schematic diagram of a long elliptical island-shaped composite fiber made using the conventional splitting method.
2 shows composite fibers arranged in layers, and FIG. 2(b) shows composite fibers arranged in two rows in layers. 1 is an oblong island component, and 2 is a sea component.

〔Example〕

Next, embodiments of the present invention will be specifically explained using examples.

It should be noted that parts and weights in the examples refer to weights to the utmost extent.

In addition, the method for measuring the interfacial tension between polymers in the examples is the buubou method [Toshi Hata'Js: Kobunshi, Vol. 17, p. 594 (196
3)) K-yo? ), calculated using Porter's formula. That is, a molten polymer surface tension measurement device (manufactured by Shibayama Kagaku Co., Ltd.,
SS-PMZ type) to determine the surface tension γ using the following formula.

r=Δρrh”(0,5000−0,3047−+1.
219 (Mutual) 3) r r Δρ: Density difference between gas and liquid f: Gravitational acceleration r: Maximum radius of the bubble h: Distance from the plane containing the maximum radius of the bubble to the top of the meniscus Example 1 Measurement temperature 240°C, Load 325? Melt intex (hereinafter referred to as MI) measured at 7.3f710 6-
Nylon, low-density polyethylene with an MI of 18 r/10 min, and paraffinized thermoplastic polyvinyl alcohol (12 carbon atoms) as an additive to adjust the interfacial tension of the polymer.
A polymer composition in which polyethylene and paraffinized thermoplastic polyvinyl alcohol are mixed in a predetermined amount with 6-nylon in one molten system is used. They were charged into the melting system of Supplying an amount with a polymer ratio of 60:40, making the two polymer flows into a joint flow, and dividing the joint flow twice to form a sea-island structure flow in which 6-nylon is an island component and polyethylene is a sea component, It was discharged from a nozzle and wound up at a winding speed of 1200 m/min to obtain a sea-island structure conjugate fiber having an average fineness of lO denier and a number of islands of 46.

The cross-sectional structure of the composite fiber was photographed using a microscope, and the island shape was observed. The results are shown in Table 1 as a relationship between the amount of paraffinized thermoplastic polyvinyl alcohol (referred to as an additive), the interfacial tension between the polymers, and the island shape.

Table 1 In other words, the conjugate fiber of the present invention was a sea-island structure conjugate fiber with long elliptical island components in which no fusion of the island components was observed.

Example 2 A polymer composition consisting of polybutylene terephthalate, the low density polyethylene used in Example 1, and paraffinized thermoplastic polyvinyl alcohol was melted at a temperature of 250"C using the same spinning device as in Example 1, and the melt flow was temperature 25
The two polymer streams were fed into a spinning head adjusted to 0°C at a ratio of 60:40, and the two polymer streams were made into a combined stream. A sea-island structure flow was formed, discharged from a nozzle, and wound at a winding speed of 1200 m/min to obtain a sea-island structure composite fiber having an average fineness of 10 denier and 46 islands.

The cross-sectional structure of the composite fiber was observed, and Table 2 shows the relationship between the amount of additive added, the interfacial tension between polymers, and the island shape.

Table 2 In other words, the conjugate fiber of the present invention is a sea-island structure conjugate fiber with an oblong island component in which no fusion of the island component is observed.

〔Effect of the invention〕

In the present invention, when manufacturing a sea-island composite fiber having a large number of island components using a melt spinning method, it is possible to form an oblong island shape by adding an additive to the polymer that reduces the interfacial tension between the polymers. In addition, it is possible to produce a sea-island structure composite fiber having well-shaped islands that does not cause fusion of the islands even if the number of islands is increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conjugate fiber having an oblong island-shaped sea-island structure according to the present invention, and FIG. 2 is a schematic diagram of a conventional conjugate fiber having an oblong island-shaped sea-island structure. Patent applicant RiRa Shi Co., Ltd.

Claims (5)

[Claims] (1) Two types of polymers with different melt flow characteristics are melted in independent melt systems to form a melt flow, the two types of polymer flows are joined to form a joint flow, and the joint flow is repeatedly divided. A melt spinning method characterized in that an additive for reducing the interfacial tension between polymers is blended into one of the polymers when producing a sea-island structure composite fiber having an elongated island shape in the cross section of the fiber. (2) The melt spinning method according to claim 1, which is an additive that lowers the interfacial tension between polymers by 5 dyne/cm or more and 10 dyne/cm or less. (3) Claim 1 in which the additive is thermoplastic polyvinyl alcohol having a paraffin moiety in the polymer chain.
The melt spinning method according to item 1 or 2. (4) The melt spinning method according to any one of claims 1 to 3, wherein the long elliptical island shape of the composite fiber has a ratio of major axis to minor axis of at least 3. (5) The melt spinning method according to any one of claims 1 to 4, wherein the number of islands of the composite fiber is at least 15.