JPH0689484B2 - Melt spinning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the production of sea-island composite fibers having irregularly shaped islands. Furthermore, the present invention is Japanese Patent Publication No. 53-8806.
53-8807, 53-8808, 53-8809 and 58
The present invention relates to a melt-spinning method for producing a composite fiber having a sea-island structure having irregularly shaped islands, using the mixing spinning device proposed in No. 51043.

[Conventional technology]

Conventionally, as a method for producing a composite fiber having a sea-island structure, a method of determining the shape of the sea-island structure or the island structure by controlling the spinneret part of the spinning device, for example, JP-B-46-3817, JP-B-46-26895. Gazette, Japanese Patent Publication No. 58-12366 Gazette, Japanese Patent Publication
60-28922, Japanese Patent Publication No. 60-52202, etc. In addition, a method for producing a composite fiber having a sea-island structure in which one type is a sea component and the other is an island component by combining two types of polymer streams at a spinning head of a spinning device and repeating division and integration of liquid streams , For example, Japanese Patent Publication No. 47-15526, Japanese Patent Publication No. 47-1
5530 bulletin, Japanese Patent Publication No. 47-15532, Japanese Patent Publication No. 47-15535
Publication, Japanese Patent Publication No. 53-8806, Japanese Patent Publication No. 53-88
No. 07, Japanese Patent Publication No. 53-8808, Japanese Patent Publication No. 53-8809, and Japanese Patent Publication No. 58-51043.

[Problems to be solved by the invention]

In the conventional method for producing long-ellipse island-shaped sea-island structure composite fibers, the method of controlling the island shape by the spinneret structure has a limit on the number of islands.
Due to fusion, a good composite island-sea structure fiber cannot be obtained. In order to form a sea-island structure by combining the two types of polymer streams at the spinning head and repeating the division and integration of the liquid streams, increase the melt viscosity ratio of the polymer, and the polymer that becomes the island component has a difference in cohesive energy. A good sea-island structure phase cannot be formed unless the large ones are combined. In such a case, the island shape becomes circular, and it is difficult to stably form the oblong island shape. In the spinning method in which two types of polymer streams are joined at the spinning head and the liquid stream is divided multiple times to form a sea-island structure, a long elliptical island shape is stably formed, and a composite fiber with a sea-island structure is formed. It is possible to obtain the number of islands in a small number of islands. If the number of islands is increased to more than several tens of islands, cohesion and fusion between the islands occur, and a good composite fiber having a sea-island structure cannot be obtained. Especially in the range where the volume fraction of the island component is 50% or more, aggregation and fusion become remarkable.

The present invention combines two polymer streams at the spinning head,
When producing a composite fiber with a sea-island structure by repeating the liquid flow multiple times, even if the number of island components is increased, the occurrence or aggregation of islands is prevented or suppressed, and the sea-island structure of oblong island components is produced. It is to stably manufacture the composite fiber. Furthermore, it is possible to adjust the ratio of the major axis and the minor axis of the oblong island shape. Further, another object of the present invention is to provide an effective method for reproducing the shape of the core or the island shape in accordance with the shape of the inner nozzle hole of the spinneret even in the other island-shaped composite spinning method.

[Means for solving problems]

The present invention melts two kinds of polymers having different melt flow characteristics in independent melting systems to form a melt flow, and joins two kinds of polymer flows to form a joint flow,
When the conjugate flow is repeated a plurality of times to produce a composite fiber having a sea-island structure having an elliptic island shape in the cross section of the fiber, an additive for reducing the interfacial tension between the polymers is blended with any one of the polymers. The melt spinning method is characterized in that

That is, according to the present invention, two types of polymer streams having different melting characteristics are joined at a spinning head to form a joint stream, and the joint stream is divided a plurality of times to obtain at least the oblong island component.
Decrease the interfacial tension between molten polymers in any one of the two polymers, or in all if necessary, to produce a sea-island structure composite fiber having 15 islands, preferably 25 islands or more. Additives to reduce the interfacial tension between molten polymers. The preferred interfacial tension is to reduce the interfacial tension by 5 dyne / cm or more by adding an additive during fusion bonding, and
It should be 10 dyne / cm or less, preferably 7 dyne / cm or less. If the decrease in interfacial tension is small and becomes larger than 10 dyne / cm, fusion may occur when the number of islands is increased,
It becomes difficult to increase the ratio of the major axis to the minor axis of the oblong shape. Reducing the interfacial tension can not only prevent or suppress the occurrence of fusion between the islands even if the number of islands is increased, but also change the ratio of the major axis to the minor axis of the elliptical shape. Furthermore, even in the composite spinning method in which the island shape is restricted by the inner nozzle shape of the spinneret, the island shape can be formed according to the inner nozzle shape.

The additive to be added to the polymer in the present invention must be a substance that does not affect the polymer in the molten state. In the present invention, a thermoplastic polyvinyl alcohol having a polymer chain in which a paraffin portion is block-copolymerized is used as an additive having a good affinity with many molten polymers and having a large effect of reducing the interfacial tension.
The amount of the additive used is determined in consideration of various characteristics such as the characteristics of the molten polymer and the interaction between the molten polymers, but it is generally 5 to 50% by weight based on the total weight of the molten polymer. Alternatively, the total amount of the sea component polymer may be replaced with an additive.

Further, the polymer for producing the composite fiber of the sea-island structure of the present invention may be a thermoplastic polymer having melt fluidity,
For example, polyester obtained by condensation polymerization of dicarboxylic acid and diol, polyamide 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. Polymer, polyvinyl alcohol or vinyl alcohol copolymer,
Two kinds of polymers having different melt flow characteristics selected from polyvinyl chloride, polyurethane, polyester elastomer, polyamide elastomer and the like are used. In addition, in order to make the composite fiber of the sea-island structure into a leather-like sheet or a highly dense fabric, the sea component that constitutes the fiber is removed and the island component fiber is used. Is to select a polymer capable of imparting. For example, polyester, polyamide, polyolefin, polyurethane, polyester elastomer, polyamide elastomer, polyvinyl chloride and the like are suitable. On the other hand, as the sea component to be removed in the final product, for example, it is treated with a solvent or a decomposing agent such as polyolefin or olefin copolymer, polystyrene or styrene copolymer, polyvinyl alcohol or vinyl alcohol copolymer, polyester. It is a polymer that can be easily removed.

The oblong-island sea-island structure composite fiber obtained in the present invention can be used as it is as a cloth such as a woven fabric, a knitted fabric or a non-woven fabric. As a non-woven fabric for the facing of products, it has a good texture and is flexible. It is possible to fabricate a soft sheet-like material having a high strength containing fine fibers by heat-calendering the cloth. Further, by using it as a fiber for a base material that constitutes a leather-like sheet, for example, a napped suede-like sheet or pile cloth having anisotropy in gloss can be obtained.

Next, FIG. 1 shows a schematic diagram of the composite fiber of the oblong island-shaped sea-island structure of the present invention. 1 is the oblong island component, 2
Is a sea component. FIG. 2 is a schematic view of a long elliptic island-shaped composite fiber produced by a conventional splitting method. FIG. 2 (a) shows the composite fiber arranged in layers, and FIG. 2 (b) shows the layered structure. The composite fibers are shown arranged in two rows. 1 is an elliptical island component, and 2 is a sea component.

〔Example〕

Next, embodiments of the present invention will be specifically described with reference to examples.
The parts and% in the examples relate to weight unless otherwise specified.

The interfacial tension between polymers in the examples was determined by the static bubble method [Toshio Hata: Polymer, Vol. 17, p. 594 (1968)] by the formula of Porter. That is, measurement is performed using a molten polymer surface tension measuring device (SS-PM2 type, manufactured by Shibayama Scientific Co., Ltd.), and the surface tension r is calculated by the following formula.

Δρ: Difference in density between gas and liquid g: Gravitational acceleration r: Maximum radius of bubble h: Distance from plane including maximum radius of bubble to top of meniscus Example 1 Melt index measured at a measurement temperature of 240 ° C. and a load of 325 g (Hereinafter MI) is 7.3g / 10/10 6-nylon and same M
Low density polyethylene with I of 18g / 10min, and paraffinized thermoplastic polyvinyl alcohol as an additive for adjusting the interfacial tension of the polymer (paraffin terminal having 12 carbons, allyl acetate 10mol% copolymerization, saponification degree 80% polymer) Using
A polymer composition in which 6-nylon was mixed in one melting system and polyethylene and paraffinized thermoplastic polyvinyl alcohol in a predetermined amount was charged in another melting system at a temperature of 24
The ratio of each polymer was 60:40 in the spinning head that was melted at 0 ° C and the melt flow was adjusted to 240 ° C (the spinning head mechanism and nozzle part are those described in JP-B-53-8807). Is supplied, the two polymer streams are made into a joint stream, and the joint stream is divided into two to form a sea-island structure stream in which 6-nylon is an island component and polyethylene is a sea component, and is discharged from a nozzle and the winding speed is It was wound at 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 photographed in a micrograph to observe the island shape. The results are shown in Table 1 in terms of the relationship between the added amount of paraffinized thermoplastic polyvinyl alcohol (referred to as an additive), the interfacial tension between the polymers, and the island shape.

That is, the conjugate fiber of the present invention was a sea-island structure conjugate fiber having an oblong island component in which no fusion of the island component was observed.

Example 2 A polymer composition comprising polybutylene terephthalate and 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 molten stream was heated to a temperature of The spinning head adjusted to 250 ° C was supplied with an amount of 60:40 for each split, and the two polymer streams were combined into a joint stream, and the joint stream was divided into polybutylene terephthalate as the island component and polyethylene as the sea component. 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 the relationship between the amount of the additive added, the interfacial tension between the polymers and the island shape is shown in Table 2.

That is, the conjugate fiber of the present invention was a sea-island structure conjugate fiber having an oblong island component in which no fusion of the island component was observed.

〔The invention's effect〕

According to the present invention, when producing a sea-island structure composite fiber having a large number of island components by the melt spinning method, a long elliptical island shape can be formed by adding an additive that lowers the interfacial tension between the polymers to the polymer. It is possible to produce a sea-island structure composite fiber having favorable irregular-shaped islands that do not cause island fusion even if the number of islands is increased.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a conjugate fiber having a long elliptic island-shaped sea-island structure of the present invention, and FIG. 2 is a schematic diagram of a conventional conjugate fiber having a long elliptic island-shaped sea-island structure.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-70003 (JP, A) JP 48-13169 (JP, B2) JP 47-47533 (JP, B2) JP 52-2 8887 (JP, B2) JP-B-43-14190 (JP, B2)

Claims (4)

[Claims] 1. Two kinds of polymers having different melt flow characteristics are melted by independent melting systems to form a melt flow, and 2
When polymer streams of different types are joined to form a joined stream, and the joined stream is repeatedly divided to produce a sea-island structure composite fiber having an elliptic island shape in a fiber cross-section, a block chain copolymerizes a paraffin portion on a polymer chain. Melt spinning characterized in that thermoplastic polyvinyl alcohol is blended in either or both of the two polymers, or the total amount of the sea component polymer is replaced by the thermoplastic polyvinyl alcohol and blended. Law. 2. The melt spinning method according to claim 1, which is an additive for reducing the interfacial tension between polymers to 5 dyne / cm or more and 10 dyne / cm or less. 3. The melt-spinning method according to claim 1, wherein the elliptical island shape of the conjugate fiber has a ratio of major axis to minor axis of at least 3. 4. The melt spinning method according to any one of claims 1 to 3, wherein the number of islands of the composite fiber is at least 15.