JPH0377312B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flexible, high-strength rope that is mainly composed of synthetic fibers with a flat cross-section, high strength, and high elastic modulus made of flexible polymer, and has excellent color tone and weather resistance. Traditionally, fibers for ropes include natural fibers such as Manila hemp, and synthetic fibers such as polypropylene, polyethylene, nylon, and vinylon, but in recent years synthetic fibers have been increasingly used due to their mechanical properties, light weight, and economy. It's starting to look like this. However, even if the fibers that make up the rope are synthetic fibers, their tensile strength is at most 9.5 g/denier, and to make a high-strength rope, it is necessary to increase the thickness of the rope, which makes it stiff and difficult to handle. There were problems with gender and the weight of the rope itself. Very recently, aromatic polyamide fibers with high tenacity of 20 g/denier or more have been developed.
It is also being considered in the rope field. However, this type of fiber has a higher raw material cost than the molecular structure of the polymer, so it is expensive, it is yellow or golden yellow and has poor color development, and its elongation is too low.
There are problems such as poor weather resistance. Furthermore, since wet spinning is used during production, it is extremely difficult to obtain yarns with single fibers of 2 deniers or more due to the problem of coagulation speed. These problems have made the rope industry hesitant to adopt it. The inventors of the present invention have made intensive studies to solve the above-mentioned drawbacks of the conventional ropes, and as a result have found patent application No. 152261 of 1983, patent application No. 154622 of 1988, and patent application No. 161044 of 1988. By using high-strength, high-modulus synthetic fibers made of flexible polymers such as polyethylene obtained by the method described in No. It was discovered that a high-strength rope that solves the above problems can be obtained, and the present invention was developed. That is, the present invention provides a fiber having a tensile strength of at least 20 g/denier, a tensile modulus of at least 300 g/denier, and a cross-sectional flattening ratio of 1.7 or more, which may have numerous longitudinal grooves on its surface. It is a high-strength rope characterized by being mainly composed of synthetic fibers consisting of flexible polymer chains. The high-strength rope referred to in the present invention refers to a rope that has a higher strength value per thickness than conventional ropes, such as Japanese Industrial Standard JIS-L2703, JIS-
L2704 and JIS-L2705 specify the rope thickness that must be satisfied for vinylon rope using vinylon spun yarn, nylon rope using nylon multifilament yarn, and polyethylene rope using polyethylene monofilament yarn, respectively. Although the tensile strength is specified, it refers to a rope that has a tensile strength that is approximately twice or more than these specified values. Expressing this in terms of tensile strength per unit area of rope cross section, the rope has a tensile strength of about 40 Kg/mm ² or more, preferably about 55 Kg/mm ² or more. By the way, the conventional thickness (diameter) is 12 to 100.
Tensile strength of mm nylon rope is 18~26Kg/ ^mm2
It is. The flexible molecular chain referred to in the present invention refers to a molecular chain consisting of molecular bonds that can rotate when subjected to stress or heat, and is a molecular chain that constitutes wholly aromatic polyamide, wholly aromatic polyester, etc. is not included in this. In the present invention, synthetic fibers consisting of flexible polymer chains include, for example, polyolefins such as high molecular weight polyethylene and polypropylene, polyacrylonitrile,
Examples include, but are not limited to, poly(vinylidene fluoride). The synthetic fiber that is the main component of the rope of the present invention has a tensile strength of 20 g/denier or more, preferably 25 g/denier or more, and 300 g/denier or more.
It preferably has a tensile modulus of 550 g/denier or more, and also satisfies a cross-sectional flattening ratio of 1.7 or more, preferably 3 or more. The flattening ratio referred to in the present invention is the length of the major axis (amm) and the length of the minor axis (b) in the cross section perpendicular to the fiber axis.
mm) is measured, and the flattening rate is the value shown in a/b. Here, in the case of fibers having a tensile strength of less than 20 g/denier, the high strength rope targeted by the present invention cannot be obtained. In addition, when used as a rope, in order to minimize the elongation of the rope when loaded, the tensile modulus of the fiber must be 300 g/denier or more, preferably 550 g/denier or more. If it is less than 300 g/denier, when made into a rope, it will elongate too much, which is unfavorable in terms of handling. Furthermore, the synthetic fibers that are the main components of the rope of the present invention have a cross-sectional flattening ratio of 1.7 or more, preferably 3 or more, and when used as a rope, they reduce the bending stiffness of the rope and have excellent properties. Gives flexibility and improves handling. If the flattening ratio is less than 1.7, the rope will become rigid and difficult to handle, which is not preferable. By imparting numerous longitudinal grooves to the surface of the synthetic fibers that are the main component of the rope of the present invention, the contact area at the contact part is reduced when the rope is made, reducing frictional damage to the rope. The present inventors have also found that it is possible to do so. The multi-row grooves referred to herein are countless multi-row grooves arranged in the fiber axis direction, and the multi-row grooves include 2 or more grooves, particularly 5 to 5 grooves, per 10μ of the average distance in the outer circumferential direction of the cross section of the fiber. By arranging 50 pieces, the above-mentioned effect becomes remarkable. The fibers that are the main components of the high-strength rope of the present invention have a tensile strength of 20 g/denier or more, preferably 25 g/denier or more.
In order to satisfy the tensile modulus of 300 g/denier or more, preferably 550 g/denier or more, it is necessary to select a polymer with a high molecular weight and good crystallinity. The original color of the fiber is colorless or white, and it can be dyed according to the purpose or preference, and it can also be dyed into a color with good color development even by spun dyeing. Further, the fiber may be in any form such as multifilament, monofilament, or spun yarn. The rope of the present invention preferably contains at least 50% by weight, especially 75% by weight or more of the fibers that are the main component of the rope. If the content is less than 50% by weight, it is not preferable because it becomes difficult to obtain the high-strength rope targeted by the present invention. The high-strength rope of the present invention can be used in cases where the fibers that are the main component of the yarn constituting the rope are of one type.
This does not preclude the construction of a rope by mixing one or more other fibers. The rope of the present invention may be made of, for example, high molecular weight polyethylene (for example, a weight average molecular weight of 1×10 ⁵ or more,
The gel fiber produced by the solution spinning is produced by solution spinning using ultra-high molecular weight polyethylene (preferably 1×10 ⁶ or more), and the temperature at the inlet of the drawing zone is set higher than the melting point of the supplied fiber. By a new high-magnification drawing method, the fiber is drawn in multiple stages while passing through a drawing zone where the temperature at the outlet of the drawing zone is higher than the melting point of the supplied fiber and lower than the melting point of the fiber after drawing. The resulting high-strength, high-modulus fibers with flexible polymer chains are used as raw material,
For example, it can be easily manufactured based on the processing method and hammering method of JIS-L2703 (1978), JIS-L2704 (1978), and JIS-L2705 (1969). The high-strength rope of the present invention may have a surface treated with a synthetic resin such as paraffin or polyurethane, or the surface of the rope may have a tensile modulus of elasticity.
It may be a fiber of up to 100 g/denier, for example coated with polyurethane. These surface treatments and surface coatings are effective when friction between fibers within the rope or external friction against pulleys, guides, etc. is a problem. According to the present invention, although it is thinner and stronger than conventional ropes and has extremely high strength,
A rope with excellent handling properties can be obtained without losing its flexibility. The rope of the present invention is inexpensive and has excellent color tone and light resistance compared to ropes made from conventional aromatic polyamide fibers. In particular, ropes with numerous grooves on the surface of the fibers that make up the rope have excellent abrasion resistance. It has extremely excellent properties and has succeeded in overcoming the drawbacks of conventional synthetic fiber ropes, and its technical significance is extremely large. The method of measuring physical properties used for evaluation of the present invention is as follows. <Measurement method for strength and elongation properties of fibers> Using Tensilon manufactured by Toyo Baldwin Co., Ltd., the S-S curve of a single fiber was measured under the conditions of a sample length (gauge length) of 30 mm and an elongation rate of 100%/min, and the tensile strength was determined. (g/d) and initial elastic modulus (g/d) were calculated. The initial elastic modulus was calculated from the maximum slope near the origin of the SS curve. Each characteristic value was the average value of the values measured for 20 single fibers. <Rope characteristic values> According to the method specified in JIS-L2705 (1969) <Rope cross-sectional area> The area of the circle was calculated from the thickness determined according to JIS-L2705 (1969) 6.6. The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. <Rope abrasion resistance> Under a load of 20% of the breaking strength, the rope was bent 180° using two pulleys at a rate of 3 reciprocations per minute, and this operation was repeated until it was cut. Example 1 Ultra-high molecular weight polyethylene having a flexible polymer chain with a weight average molecular weight of 1.9 x 10 ⁶ was melt-spun, and the resulting gel fiber was drawn at a high magnification in multiple stages to a tensile height of 35 g/d, Tensile modulus 1000g/d,
High-strength polyethylene fibers with a fineness of 1500 d and a cross-sectional flattening ratio of 5.6 and numerous grooves on the fiber surface were obtained.
Using the multifilament of the fiber, a three-stranded rope with a thickness of 30 mm was made, and this was used as Experiment No. 1. Next, solution spinning was carried out using polyethylene with the same molecular weight as in Experiment No. 1, and the obtained gel fiber was drawn at a high magnification in multiple stages to obtain a cross section with a tensile strength of 37 g/d, a tensile modulus of elasticity of 1200 g/d, and a fineness of 1500 d. Polyethylene fibers with a flattening ratio of 1.8 were obtained. Experiment No. 2 was prepared by making a three-strand rope with a thickness of 30 mm from the multifilament of the fiber in the same manner as in Experiment No. 1. Furthermore, solution spinning was carried out using polyethylene having the same molecular weight as in Experiment No. 1, and the resulting gel fiber was stretched at a high magnification in multiple stages to obtain a flat cross-section with a tensile strength of 32 g/d, a tensile modulus of elasticity of 950 g/d, and a fineness of 1500 d. conversion rate
1.5 polyethylene fibers were obtained. A three-strand rope with a thickness of 30 mm was prepared from the multifilament of the fiber in the same manner as in Experiment No. 1, and it was designated as Experiment No. 3. Then,
Solution spinning was performed using polyethylene having the same molecular weight as in Experiment No. 1, and the resulting gel fiber was stretched to obtain a tensile strength of 18 g/d, a tensile modulus of 450 g/d,
Polyethylene fibers with a fineness of 1500 d and a cross-sectional flattening ratio of 5.3 were obtained. Experiment No. 1 using multifilament of this fiber
In the same manner as above, a 30 mm thick three-stripe rope was created and used as Experiment No. 4. For comparison, three ropes with a thickness of 30 mm were made in the same manner as in Experiment No. 1 using commercially available 1260 denier nylon multifilament, 380 denier polyethylene monofilament, and 5th vinylon spun yarn as yarns. They were designated as Experiments No. 5, No. 6, and No. 7, respectively. Table 1 shows the characteristics of each rope.

[Table] ◎ Best ○ Good △ Not good ×
Worst ***Number of times until breakage ≧30,000, **30,000>Number of times until breakage≧20,000, *Number of times until breakage<20,000 As is clear from Table 1, the high strength rope of the present invention It can be seen that although it is extremely strong, it has sufficient flexibility in handling. In addition, the high strength rope of the present invention only needs to be about half as thick as the conventional nylon multifilament rope in order to obtain the same breaking force as the rope. Furthermore, as seen in the comparative example of Experiment No. 3, it can be seen that when the cross-sectional flattening ratio of the rope constituent fibers is lower than 1.7, high strength can be obtained, but the flexibility is inferior. Furthermore, from the comparative example of Experiment No. 4, the tensile strength of the rope's constituent fibers was 20
It can be seen that the high strength rope of the present invention cannot be obtained because it is as low as 18 g/d, which is less than g/d. Example 2 Using the same multifilament of high-strength polyethylene fiber as used in Experiment No. 1 of Example 1, an 8-strand rope with a thickness of 90 mm was made, and this was used in Experiment No. 1.
It was set as 8. For comparison, an eight-stripe rope with a thickness of 90 mm was prepared using polyparaphenylene terephthalamide fiber 1500 denier multifilament, and this was designated as Experiment No. 9. The properties of both ropes are shown in Table 2.

[Table] As is clear from Table 2, it is clear that the high strength rope of the present invention is superior to aromatic polyamide fibers in terms of color tone and weather resistance.

Claims (1)

[Claims] 1. A fiber having a tensile strength of at least 20 g/denier, a tensile modulus of at least 300 g/denier, and a cross-sectional flattening ratio of 1.7 or more, which has numerous longitudinal grooves on its surface. A high-strength rope characterized by being mainly composed of synthetic fibers consisting of fiber flexible polymer chains. 2. The high-strength rope according to claim 1, wherein the rope has a breaking strength of at least 40 Kg/mm ² (rope cross-sectional unit area), preferably 55 Kg/mm ² (rope cross-sectional unit area). 3. The high-strength rope according to claim 1 or 2, wherein the surface of the rope is resin-treated with synthetic resin or the like. 4. The high-strength rope according to any one of claims 1 to 3, wherein the surface of the rope is coated with fibers having a tensile modulus of 100 g/denier or less.