JPS61613A - Preparation of yarn having high specific gravity - Google Patents

Abstract

PURPOSE:To obtain the titled yarn having mechanical characteristics, wear resistance, feeling, etc. and high specific gravity, by spinning a resin composition obtained by adding barium sulfate having specific particle diameters to polyethylene, drawing it at a multiple stage at >= a specific draw ratio. CONSTITUTION:(A) 100pts.wt. polyethylene having >=0.94g/cm<3> density is blended with (B) 20-500pts.wt. barium sulfate having 0.1-3mu average particle diameter to give a resin composition, which is subjected to melt spinning to form undrawn yarn. Then, the undrawn yarn is drawn at a multiple stage in such a way that total draw ratio is >=8 times, preferably >=10-16 times, to give the aimed yarn having high specific gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a conventional polyolefin synthetic fiber, which has particularly good mechanical properties and abrasion resistance.

The present invention relates to a method for producing high specific gravity yarn that has a good texture and a high specific gravity.

[Conventional technology]

Synthetic fibers based on polyolefins such as polyethylene and polypropylene are widely used in the fishing industry, such as fishing nets and ropes, due to their excellent mechanical properties such as tensile strength and knot strength. 9 It is unsuitable for applications such as hand ropes that are submerged in the sea because of its low specific gravity.

If you want to increase the specific gravity, there is a way to attach stones, lead alloys, etc. to silk, rope, etc. as sediment.

There is a disadvantage that nets, ropes, etc. do not sink uniformly because the load is applied locally, and the net between the sinkers floats up due to being blown by the tide.Other methods include specific gravity. There is a method of mixing and twisting other fibers with large fibers, such as polyester fibers and vinylidene chloride fibers, but the work is complicated because different types of fibers are mixed and twisted, and vinylidene chloride in particular has poor strength, so there are many problems with thread breakage during processing. Disadvantages: A fiber that is a single fiber and has the excellent mechanical strength and high specific gravity of a polyolefin synthetic fiber.The simplest method for producing so-called high specific gravity yarn is to add a zinc compound (specific gravity 5 or more) (Japanese Patent Publication No. 51-37378, Japanese Patent Publication No. 55-31205, etc.), a method of kneading a lead compound (ratio N9 or more) into polyolefin resin (Japanese Patent Publication No. 46-22347, Japanese Patent Publication No. 47-2937)
5, etc., a method of kneading a lead compound into vinyl chloride resin (Japanese Unexamined Patent Publication No. 48-8332, etc.).

[Problem that the invention seeks to solve]

Normally, in the production of polyolefin synthetic fibers, etc., stretching is carried out at a high magnification of 9 times or more and at a high speed of 100 m/min or more in order to improve mechanical strength. When a composition containing 40 wt % or more of an inorganic filler such as a zinc compound or a lead compound is stretched using the usual method for producing polyolefin synthetic fibers, only the base polyolefin resin is stretched and the inorganic filler is stretched. is left behind and cracks form between the two, resulting in numerous voids. Therefore, despite the addition of a large amount of a high specific gravity inorganic filler, not only the specific gravity strength decreases, but also stretch breakage occurs during stretching, which tends to cause operational troubles.

Therefore, in the production of such high specific gravity yarn, C has a drawing ratio of 3.
~8% low and stretching speed 20~100m/win
It is necessary to do so within the range of Furthermore, the obtained high specific gravity yarn also has a low stretching ratio and therefore has poor mechanical strength, which poses a practical problem. If the stretching ratio is increased, the tensile strength is improved, but as the stretching ratio is increased, the voids also increase, the specific gravity rapidly decreases, and stretching breaks are more likely to occur.

Furthermore, the drawing speed also has a strong correlation with the generation of voids.

When the drawing speed is increased, the number of voids increases, and the specific gravity rapidly decreases.

In order to prevent the generation of voids, a method of using a resin that has poor compatibility with the base resin but is compatible with the inorganic filler (% Kosho 57
-20407) has been proposed, but this requires a stretching of 3 to 8 times at most and a stretching speed of around 70 m/min, making high-magnification and high-speed stretching impossible.

In addition, a method in which a rolling process is further performed after stretching to eliminate voids generated during the stretching process (% Kosho 55-31205)
has also been proposed, but it has the fatal drawback that the specific gravity of directly rolled yarn increases, but the tensile strength decreases. In addition, the method of introducing lead compounds such as lead oxide is marine pollution 1.
This is not desirable due to problems with the working environment. In other words, the reality is that there are no satisfactory conventional high specific gravity yarns.

[Means to solve problems]

In view of these circumstances, the inventors of the present invention have conducted intensive studies on a method for producing high-density polyolefin yarns having good physical properties such as 9 mechanical strength at high speed. It was discovered that by using barium sulfate having a specific particle size as an agent and performing multi-stage stretching at a specific stretching ratio or higher, a yarn with fewer voids could be obtained even if the stretching speed was increased.After further research, the present invention was finally achieved. It has been completed.

That is, in the present invention, a resin composition in which 20 to 500 parts by weight of barium sulfate with an average particle size o of 1 to 3 μm is added to 100 parts by weight of polyethylene having a density of 0.94 f/i or more is spun, and the total stretching ratio is This is a method for producing a sieve specific gravity yarn, which is characterized by carrying out multistage stretching so that the yarn has a specific gravity of 8 or more.

The polyethylene with a density of 0.94 f/cwl1 or more used in the present invention refers to ordinary polyethylene obtained by medium or low pressure methods, copolymerized polyethylene such as linear polyethylene copolymerized with alternative olefins, and mixtures thereof. Among them, especially those with a melt index of 0.01~
io fAo min, preferably 0.05 to 5 flLO min,
Particularly preferably, it is 0.1 to 2.01 Ao.

If the density of polyethylene is less than 0.94, sufficient mechanical strength cannot be obtained, and if the melt index is outside the above range, the compatibility with barium sulfate will be poor and a large amount of voids will easily occur during extrusion. So I don't like it.

The density here is the value measured according to A8TM-D-1505, and the melt index is the value measured according to A8TM-D-1505.
1238-527 (load: 2.16Kt).

The barium sulfate in the present invention has an average particle size of 0.1 to 3 μm.
, preferably 0.5 to 2 μm.

If it is less than 0.1 μm, foaming will be severe, and if it is more than 3 IIm, the dispersibility will be poor and stretch breakage will easily occur.

The amount of barium sulfate added is usually 9 to 500 parts by weight, preferably 40 to 200 parts by weight.

If the specific gravity is less than 500 parts by weight, it is difficult to obtain a yarn with sufficient strength.

If necessary, various dispersants, stabilizers, pigments, etc. may be added to the composition used in the present invention as long as the purpose is achieved.

Examples of dispersants include glycerin-based agents such as glycerin monopalmitate, glycerin monostearate, etc. rR
Examples include fatty acid monoesters, metal soaps such as magnesium stearate, calcium stearate, and lithium stearate, titanate coupling agents such as isoglopyl triisostearoyl titanate, and lubricants such as stearic acid and polyethylene wax.

Examples of stabilizers include amine antioxidants such as phenyl-α-nafbubulamine and phenyl-β-nastylamine, 2,6-di-tert-butyl-4-methylphenol, and tetrakis-[methylene-(3, 5-di-tert-butyl-4-/1hydroxyhydroxy/namate)
] Examples include 7-enol antioxidants such as butane.

[Effect]

In the present invention, a high specific gravity yarn is produced by spinning the above composition and then drawing it in multiple stages. The obtained product is melt-spun using an ordinary short-sleeved screw extruder, and the total stretching ratio is 8 or more, preferably 10 to 16 times, particularly preferably 12 times.
A method of performing multistage roll stretching of at least two or more stages at a magnification of up to 14 times is exemplified. In this case, if the stretching ratio is 8 times or less, the high strength and high specific gravity yarn targeted by the present invention cannot be obtained.
In addition, unless multi-stage stretching of at least two or more stages is performed, a good balance between a good hand feel and specific gravity 9 strength cannot be maintained. The stretching temperature at this time is preferably in the range of 100 DEG C. to 100 DEG C., and the heating method may be either dry or wet.

According to the method of the present invention, stable production is possible even when drawing at a high speed of e 150 m/min or higher, and the resulting high-density yarn has good mechanical properties and texture of conventional polyethylene fibers. Of course, it has a great feature of excellent abrasion resistance, so it can be used for fixed nets, purse nets, and long lines! It can be widely used in fishing nets, ropes, etc. that are submerged in the sea, such as I.

〔Example〕 The present invention will now be explained in more detail with reference to Examples.

Example-1 Observance 0.964 fΔd, melt index sail 351
A-powder polyethylene/(Product name HIZEX 52008
:Mitsui Petrochemicals Co., Ltd.) Barium sulfate 65 with 100 heavy gongs and an average particle size of 0.8μ JB-kl:tJ e
A composition consisting of 2 pre-parts of chryseri/monostearate and 0.5 sub-parts of 2.6-dicuteyary petitrubanol (urno) was made into pellets using a vented twin-screw extruder. The undrawn yarn was melt-spun at 280°0 using an ordinary single-screw extruder to form an undrawn yarn.Then, the undrawn yarn was stretched at a temperature of 98°C, a stretching ratio of 12
Three-stage stretching was performed at a stretching speed of 183 m/min.

Fineness 600 d, specific gravity 1.23, tensile strength 5.6
A high specific gravity yarn of S'/d was obtained.

These physical properties are shown in Table 1 along with tensile elongation and knot strength.

Note that the measurement of specific gravity is based on JIS-Z-8807.

The tensile test was conducted using a Tensilon universal testing machine under the conditions of a distance between chucks of 500 mm, a tensile speed of 500 sB/min, a measuring temperature of 20° C., and a humidity of 65%.

Example-2 Density 0.954 f/lri, melt index 0
．． 90 f, A-powder high-density polyethylene (trade name: Hi-Zex 50008, manufactured by Nimitsui Petrochemical Industries, Ltd.) 100
140 parts by weight of barium sulfate with an average particle size of 0.8μ! it
% was added, and then spun and stretched in the same manner as in Example 1. The specific gravity was 1.62, and the tensile strength K was 3. A high specific gravity yarn of 4 was obtained. Its physical properties are shown in Table 1.

Example-3 Density Q, 954 f/ad, melt index 0.
9 of 70 minutes polyethylene (product name Hi-Zex 50)
00 S: 250 parts by weight of barium sulfate having an average particle size of 0.81 was added to 100 parts (manufactured by Mikata Petrochemical Industry Co., Ltd.) and spun and drawn in the same manner as in Example 1, resulting in a specific gravity of 1. 73, a high specific gravity yarn with a tensile strength of 2.1 t/A was obtained.

Its physical properties are shown in Table 1.

Comparative Example-1 Density 0.964 f/cd, Melt Index 0.
A simple substance of 35 t, Aa9+ polyethylene (trade name HIZEX 52008, manufactured by Mikata Petrochemical Industry Co., Ltd.) was spun and drawn in the same manner as in Example 1 to obtain a polyethylene filament. Its physical properties are shown in Table 1.

Comparative Example-2 Density 0.924 t/cd, Melt Index 0-
40? , lro polyethylene (part name Betrocene 298: manufactured by Toyo Ichida Kogyo Co., Ltd.) was used in the following example.
The yarn was spun and drawn in the same manner as in 1 to obtain a high specific gravity yarn. Its physical properties are shown in Table 1.

Comparative Example 3 A single specific gravity yarn was obtained by spinning and drawing in the same manner as in Example 1, except that the stretching ratio was increased to 7 times.

Its physical properties are shown in Table 1.

Comparative example-4 Except that barium sulfate with an average particle size of 06 μm was used.

The yarn was spun and drawn in the same manner as in Example 1 to obtain a high specific gravity yarn. Its physical properties are shown in Table 1.

Comparative example-5 Except that barium sulfate with an average particle size of 4.2 μm was used.

The yarn was spun and drawn in the same manner as in Example 1 to obtain a high specific gravity yarn. Its physical properties are shown in Table 1.

Comparative Example 6 A high specific gravity yarn was obtained in the same manner as in Example 1, except that one-stage stretching was performed to the same stretching ratio.

Its physical properties are shown in Table 1.

Comparative Example-7 Density 0.964 f/cd, Melt Index XQ
, 100 parts by weight of polyethylene (trade name HIZEX 52008: manufactured by Mitsui Petrochemical Industries, Ltd.) containing 35 fflo of lead oxide (Retage; RXS K-1456,
65 parts by weight of Industrial No. 1) was added, and spinning and drawing was carried out in the same manner as in Example-1.

However, if the stretching ratio is increased to 8 times, stretching breakage occurs, so the stretching ratio was set to 7.5 times. Table 1 shows the physical properties of the high specific gravity yarn obtained.

Table 1 Physical properties of high specific gravity systems [Effects of the invention] Table 1 Physical properties of high specific gravity systems [Effects of the invention] Table 1 Physical properties of high specific gravity systems
[Effects of the invention] Note) *: MI = Melt Index Rinji Collect the 5 obtained threads, collect 3 of them and twist them together, and then collect these 3 twisted threads to create a twisted twine. . I put a 2Kf load recommendation on this twine,
The number of times until the contact point broke on a part of the 39 mesh grinder was measured.

〔Effect of the invention〕

According to the configuration of the present invention as shown in Table 1.

It was confirmed that it was possible to produce a high specific gravity yarn that satisfied the required physical properties.

Claims (1)

[Claims] 1) Polyethylene 10 with a density of 0.94g/cm^3 or more
0 parts by weight of barium sulfate with an average particle size of 0.1 to 3 μm
1. A method for producing a high specific gravity yarn, which comprises spinning a resin composition containing 0 to 500 parts by weight and stretching the yarn in multiple stages so that the total stretching ratio is 8 or more.