JP3462915B2 - High specific gravity high strength core-sheath composite fiber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber for fishery materials, and more particularly to a core-sheath composite fiber having a high specific gravity and a high strength which is excellent in safety and suitable for fishing nets. It is. 2. Description of the Related Art Polyester fibers have various excellent properties and are also used as fibers for fishery materials such as fishing nets (see, for example, Japanese Patent Publication No. 58-38530). Although it is a synthetic fiber having a relatively large specific gravity, it has a high sedimentation speed in water and has a higher specific gravity in order to improve the shape retention of the fishing net against the tide. [0003] In recent years, in order to improve productivity, a fishing net made of Russell knitting capable of high-speed netting has become the mainstream, and polyester fibers for fishing nets have high strength and high abrasion resistance to withstand high-speed netting. Things are desired. Hitherto, various methods have been proposed for obtaining high specific gravity synthetic fibers by incorporating high specific gravity fine powder, but the high specific gravity fine powder is toxic to compounds such as lead and zinc, and relatively high. A substance with a low specific gravity is used, and there is a problem in safety.Addition of a large amount is necessary to obtain a fiber with a high specific gravity. It was difficult to obtain a strong fiber. An object of the present invention is to provide a fiber for fishery materials, especially a fiber having a high specific gravity and a high strength which is excellent in safety and is suitable for a fishing net. [0006] The present invention solves the above-mentioned problems, and the gist thereof is as follows. A sheath layer comprising a polyester resin and a core layer comprising a resin having a high specific gravity fine powder selected from tungsten and a tungsten compound having an average particle diameter of 1 μm or less and a maximum particle diameter of 2 μm or less, and having a compatibility with the resin of the sheath layer. Consisting of the following formula ~
Satisfies, specific gravity is 1.7-2.83 , tensile strength is 45-72.8kg / m
m ² , a high specific gravity, high strength core-sheath composite fiber. 0.03 ≦ X ≦ 0.20 0.10 ≦ Y ≦ 0.70 0.01 ≦ XY ≦ 0.10 where X is the volume fraction of the high specific gravity fine powder in the core layer, Y
Indicates the volume fraction of the core layer with respect to the whole fiber. Hereinafter, the present invention will be described in detail. [0008] As described above, fibers for marine materials are required to have not only high specific gravity but also high strength. The sheath layer resin is responsible for the strength of the fiber. In the present invention, as the sheath layer resin, a polyester resin that exhibits high strength by stretching is used. As the polyester resin, polyethylene terephthalate, polybutylene terephthalate, aliphatic polyester and the like are used, but polyethylene terephthalate is most preferable in consideration of fiber strength and economy. [0010] As described above, since the fishing net fiber is also required to have abrasion resistance, it is necessary to prevent peeling at the interface between the sheath layer and the core layer. It is necessary to use a material having compatibility with the polyester resin of the sheath layer. Usually, the same polyester resin as the sheath layer resin is used for the core layer resin. In the present invention, the high specific gravity fine powder includes
Tungsten or a tungsten compound fine powder having high specific gravity and high safety is used. Specific examples of the tungsten compound include tungsten carbide, tungsten oxide, tungsten titanium carbide, tungsten titanium tantalum carbide, and the like. The high specific gravity fine powder has an average particle size of 1
It is necessary that the particle diameter is not more than μm and the maximum particle diameter is not more than 2 μm. When such a fine powder is used, it is uniformly dispersed in the resin, and a fiber having good spinning properties and high strength can be obtained. If the high specific gravity fine powder has an average particle size of more than 1 μm or a maximum particle size of more than 2 μm, the spinnability deteriorates and high strength fibers cannot be obtained. The high specific gravity fine powder is blended into the core layer and made into a composite fiber together with the sheath layer component. At this time, it is necessary to satisfy the above formulas (1) to (4). First, the volume fraction X of the high specific gravity fine powder in the core layer material is calculated in the range of the equation, that is, 0.03 to 0.20, preferably
It is necessary to set it to 0.04 to 0.15. If X is too large, the workability and spinning properties of the core layer material are significantly reduced, and
The problem of interface delamination arises because the compatibility with the sheath layer resin is deteriorated. On the other hand, if X is too small, the specific gravity of the core layer material sufficient to obtain the high specific gravity core-sheath composite fiber cannot be obtained. Since the specific gravity of the high specific gravity fine powder in the present invention is very large, the specific gravity of the core layer material can be sufficiently increased as long as X satisfies the expression. Next, the volume fraction Y of the core layer material of the entire fiber is calculated in the range of the equation, that is, 0.10 to 0.70, preferably 0.10 to 0.70.
It must be 0.60. If Y is too large, it is difficult to maintain a strength that can withstand high-speed netting. On the other hand, if Y is too small, specific gravity sufficient to obtain a high specific gravity core-sheath type composite fiber cannot be obtained. As X increases, the specific gravity of the core layer material increases, but the strength of the core layer material decreases. For this reason, in order to obtain a fiber having a high specific gravity and a high strength, it is necessary to make an appropriate Y according to X.
And Y must be in the range of the equation, that is, 0.01 to 0.10, preferably 0.02 to 0.07. If this product is too large, it will be difficult to maintain strength that can withstand high-speed netting, and the volume fraction of the sheath layer will not be sufficient, and wear resistance will decrease. On the other hand, if the product is too small, it is not possible to obtain a specific gravity sufficient to obtain a high specific gravity core-sheath type composite fiber. By simultaneously satisfying the expressions (1) and (2),
For the first time, a core-sheath type composite fiber having a high specific gravity and a strength and abrasion resistance enough to withstand high-speed netting can be obtained. The fiber of the present invention must have a specific gravity of 1.7 to 2.83 and a tensile strength of 45 to 72.8 kg / mm ² . Specific gravity
If it is 1.7 or more, it is possible to obtain a fishing net with a small angle of blow and excellent fishing operability. In addition, the tensile strength is 45kg
If / mm ² or more, Russell knitting, which is a high-speed net making method, is possible. The fiber of the present invention as described above has a tensile strength of 35 kg after a reciprocating friction test by a friction test method described later.
/ Mm ² or more. The fiber of the present invention can be produced by subjecting a composite melt-spinning to a conventional method, drawing, and, if necessary, heat-treating. For example, first, the core layer material and the sheath layer material are melted at 230 to 350 ° C., preferably 250 to 310 ° C., respectively, and a concentric composite yarn is spun. If the spinning temperature is too low, it is difficult to completely melt, and if the spinning temperature is too high, thermal decomposition of the polymer occurs, which is not preferable. The spun yarn is cooled by a liquid bath or gas blowing at 0 to 100 ° C, preferably 10 to 90 ° C. If the cooling temperature is too low, it is difficult to control the temperature and the workability deteriorates. If the cooling temperature is too high, the solidification of the cooling becomes incomplete, which is not preferable. The cooled and solidified yarn is stretched after or once without winding. The stretching can be carried out in one stage or in two or more stages, but usually a two-stage stretching method is employed. That is, using a liquid bath at 60 to 130 ° C., an oven at 100 to 200 ° C., or a heating roller at 70 to 110 ° C., perform the first-stage stretching at a magnification of 3 to 6 times, and then 130 ° C. which is higher than the first-stage stretching. ~
A method of performing second-stage stretching using a liquid bath at 270 ° C., an oven, or a heating roller so that the total stretching ratio is 5 to 8 times is preferred. In general, a liquid bath is used in the case of a monofilament, and in the case of a multifilament, both cooling and stretching are performed in a gas. The stretched yarn is subjected to a relaxation of 3 to 3 in an oven at 250 to 500 ° C. or a heating roller at 150 to 250 ° C.
A 15% relaxation heat treatment is applied. In the case of monofilament, the fineness of the yarn is as follows:
In the case of 50 to 1500 denier and multifilament, it is appropriate that the single yarn fineness is 8 to 50 denier and the total fineness is 200 to 2000 denier. In the present invention, since a fine powder of tungsten or a tungsten compound having a very large specific gravity is used as the high specific gravity fine powder, when a core layer material having the same specific gravity is obtained,
The volume fraction of the high specific gravity powder in the core layer resin is reduced as compared with the case where a conventional fine powder such as lead is used. Therefore,
Since the core layer material is excellent in processability, the draw ratio can be made higher when producing a core-sheath type conjugate fiber, and a high-strength fiber can be obtained. Further, the composite fiber of the present invention has a high strength and excellent abrasion resistance because the core layer containing the high specific gravity fine powder is appropriately covered with the sheath layer resin compatible with the core layer. ,
High-speed netting such as Russell knitting is possible. The high specific gravity fine powder used in the present invention is:
It is harmless to the human body and the environment, and has excellent safety during manufacturing and use. Next, the present invention will be described specifically with reference to examples. In addition, the measuring method is as follows. Relative Viscosity Measurement was carried out at a concentration of 0.5 g / dl and a temperature of 20 ° C. using an equal weight mixture of phenol and ethane tetrachloride as a solvent. Strength and elongation Using Shimadzu Autograph DSS-500, 20 ℃, 65%
The measurement was performed at a sample length of 25 cm and a tensile speed of 30 cm / min in an RH measurement room. Abrasion resistance A friction test was performed by the following friction test method with a load of 3.2 kg / mm ² and the number of reciprocal frictions set to 100, and the tensile strength after the test was measured. Also, observe the cross section of the fiber after the friction test,
The durability was confirmed by the presence or absence of interface separation between the core layer and the sheath layer. Friction test method As shown in FIG. 1, there is a fiber locking device 2 on a horizontal reciprocating body 1 and a metal hexagon wrench 3
Using a tester to which (material SCM-3, size 7 mm) was fixed, one end of the test fiber (length 50 cm) was fixed to the lock 2, and the other end was loaded with a load of 2.5 kg / mm ² . A weight L is attached so that the distance L between the locking tool 2 and the center of the hexagon wrench 3 is the longest.
The reciprocating motion was performed so that the distance was 25 cm and the shortest was 15 cm. The number of reciprocating strokes was 36 times / min. Example 1 Polyethylene terephthalate (PET) pellets having a relative viscosity of 1.62 and a specific gravity of 1.38 as a sheath layer material, PET having a relative viscosity of 1.62 and a specific gravity of 1.38 as a core layer material and an average particle size of 0.63 μm, a maximum particle size of 1.30 μm and a specific gravity Using pellets obtained by melting and kneading the tungsten fine powder of 19.3, a concentric sheath-core composite monofilament having the configuration shown in Table 1 was produced as follows. The above two types of pellets were melted at 285 ° C using two extruders and heated to 290 ° C.
Spinning from spinneret with four 1.3mm spinning holes, 70 ° C
And stretched 5 times in a glycerin bath at 105 ° C. , subjected to relaxation heat treatment, and wound up a 420 denier monofilament. In addition, as a comparative example, a monofilament not satisfying the conditions of the formula and the conditions was similarly obtained. Table 1 shows the results of evaluating the yarn quality performance and abrasion resistance of the obtained monofilament. [Table 1] Example 2 Using the same raw materials as in Example 1, a monofilament was produced in the same manner as in Example 1. At this time, X and Y were changed so that XY = 0.06. Further, as a comparative example, a monofilament not satisfying the conditions of the formula was similarly obtained. Table 2 shows the results of evaluating the yarn quality performance and abrasion resistance of the obtained monofilament. [Table 2] Example 3 PET pellets having a relative viscosity of 1.62 and a specific gravity of 1.38 as a sheath layer material, polybutylene terephthalate (PBT) having a relative viscosity of 1.61 and a specific gravity of 1.31 as a core layer material, an average particle diameter of 0.63 μm, a maximum particle diameter of 1.30 μm, Using pellets obtained by melting and kneading tungsten fine powder having a specific gravity of 19.3, a concentric sheath-core composite monofilament having the configuration shown in Table 3 was produced as follows. The above two types of pellets were melted at 275 ° C using two extruders and heated to 290 ° C.
Spinning from spinneret with four 1.3mm spinning holes, 70 ° C
And then stretched 5-fold in a glycerin bath at 100 ° C. , heat-relaxed and wound up a 420 denier monofilament. Further, as a comparative example, a monofilament not satisfying the conditions of the formula was similarly obtained.
Table 3 shows the results of evaluating the yarn quality performance and abrasion resistance of the obtained monofilament. [Table 3] Example 4 A monofilament was prepared in the same manner as in Example 1 except that tungsten carbide fine powder having an average particle size of 0.82 μm, a maximum particle size of 1.53 μm, and a specific gravity of 17.0 was used instead of the tungsten fine powder in Example 1. Manufactured. As a comparative example, a monofilament which does not satisfy the formula or the condition of the formula was similarly obtained. Table 4 shows the results of evaluating the yarn quality performance and wear resistance of the obtained monofilament. [Table 4] Comparative Example In place of the tungsten fine powder in Example 1, a tungsten fine powder having an average particle size of 2.14 μm, a maximum particle size of 4.41 μm, and a specific gravity of 19.3 was used, and the structure shown in Table 5 was used in the same manner as in Example 1. Monofilament was manufactured. Table 5 shows the results of evaluating the yarn quality performance and abrasion resistance of the obtained monofilament. [Table 5] When a fine powder having a large average particle size and a maximum particle size was used, the yarn-forming properties were poor or the monofilament obtained had poor yarn quality even when the conditions of the formulas (1) and (2) were satisfied. According to the present invention, there is provided a fiber for fishery material, particularly a fiber having a high specific gravity and a high strength which is excellent in safety and suitable for a fishing net.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a friction test apparatus used in an embodiment of the present invention. [Description of Signs] 1 Horizontal reciprocating body 2 Locking device 3 Hexagon wrench 4 Weight

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Inoue 23 Uji Kozakura, Uji-city, Kyoto Unitika Inside the Central Research Laboratory Co., Ltd. (56) References JP-A-6-133670 (JP, A) JP-A-62-15327 (JP, A) JP-A-60-139913 (JP, A) JP-A-4-335849 (JP, A) JP-A-6-207316 (JP, A) JP-A-62-257918 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) D01F 1/00-9/04 A01K 75/00

Claims (1)

(57) [Claim 1] A sheath layer comprising a polyester resin and a high specific gravity fine powder selected from tungsten and a tungsten compound having an average particle diameter of 1 μm or less and a maximum particle diameter of 2 μm or less,
It consists of a sheath layer resin and a core layer made of a resin having compatibility, and satisfies the following formulas (1) to (4), a specific gravity of 1.7 to 2.83 , and a tensile strength.
A high-specific-gravity, high-strength core-sheath composite fiber having a strength of 45 to 72.8 kg / mm ² . 0.03 ≦ X ≦ 0.20 0.10 ≦ Y ≦ 0.70 0.01 ≦ XY ≦ 0.10 where X is the volume fraction of the high specific gravity fine powder in the core layer, Y
Indicates the volume fraction of the core layer with respect to the whole fiber.