JP2788106B2 - Magnetic cloth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic cloth comprising magnetic composite fibers containing magnetic particles.

(Problems to be solved by conventional technology / invention) Conventionally, as a method for obtaining a fiber structure having magnetism,
(1) A method of weaving and knitting a magnetic fiber in which a normal yarn is covered by a thread-like magnet (JP-A-53-2654), and (2) A method of using a synthetic fiber in which ferromagnetic particles are uniformly dispersed therein Akira
55-98909) or a method of weaving or weaving a synthetic fiber or rubber in which a magnetic material is uniformly dispersed therein and then magnetizing it (JP-A-55-30453). (3) Mixing magnetized magnetic powder into a nonwoven fabric A method (JP-A-58-41954) has been proposed. However, each of the above methods has various problems. For example, in the cases of (1) and (2), the magnetic fibers used have poor flexibility, so that weaving and knitting are difficult, and the resulting fiber products also have disadvantages such as poor flexibility. In addition, the method (3) has disadvantages such that the magnetic force acting between the magnetic particles tends to cause aggregation of the magnetic particles, and it is difficult to uniformly mix the magnetic particles into the nonwoven fabric.

An object of the present invention is to provide a novel magnetic fabric which is easy to manufacture and highly flexible.

(Means for Solving the Problems) The present invention provides a thermoplastic polymer containing magnetic particles as a core component, a fiber-forming polymer as a sheath component, and a softening point or melting point of the core component of the sheath component. At least more
A magnetic composite fiber composed of a material having a temperature lower by 50 ° C. is used as a constituent yarn, and is magnetized in a direction perpendicular to the cloth surface at a temperature higher than the melting point or softening point of the core component and lower than the melting point or softening point of the sheath component. Hereinafter, the present invention will be described in detail.

The magnetic fiber constituting the fabric of the present invention is a magnetic composite fiber in which a magnetic component composed of a thermoplastic polymer containing magnetic particles and a protective component composed of a fiber-forming polymer are composited.

The magnetic particles of the magnetic composite fiber include iron, cobalt,
Metal particles containing nickel or the like as a main component and alloy particles containing them, magnetite, ferrite, composite metal oxides containing these iron oxides as a main component, and rare earth elements such as samarium and yttrium and 3d such as cobalt and nickel Intermetallic compounds with transition elements and neodymium
Magnetic materials exhibiting ferromagnetism and ferrimagnetism, such as rare earth elements such as iron / boron, praseodymium / iron / boron, and ternary intermetallic compound particles of iron and boron, can be used. The average particle size is usually 2 μm or less, most preferably 1 μm.

The magnetic component is composed of magnetic particles and a matrix polymer as a binder. As a matrix polymer,
Polyamide, polyester, polyvinyl-based polymer, polyolefin, polyether, polyurethane, polycarbonate and the like can be used. The mixing ratio of the matrix polymer and the magnetic particles depends on the properties of the magnetic particles and the matrix polymer to be used, and the required magnetic properties, but when strong magnetism is required, 20 to 90%, particularly 40 to 90%
85% is preferred.

As the protective component of the fiber-forming polymer of the conjugate fiber, polyamide, polyester, polyolefin, polyvinyl, polyether and any other known spinning materials can be used.

The cross-sectional shape (contour) of the composite fiber may be circular or non-circular, and is not particularly limited. However, the composite form of the magnetic portion and the protective component is important. That is, it is important that the core-sheath type has a magnetic component as a core and a fiber-forming protective component as a sheath. This is because in the present invention, the fiber is magnetized in a state where the magnetic component is softened or melted. Therefore, if the magnetic component is widely exposed on the fiber surface, the magnetic component may melt or fall off the fiber during heating magnetization and orientation. This is because the magnetic components of the fibers are fused to each other and the aesthetic appearance of the fabric is significantly impaired. 6 and 7 show an example of a fiber cross section suitable for the present invention. FIG. 6 shows a core-sheath type, and FIG. 7 shows a type in which the magnetic layer is exposed on the fiber surface with a very small width. In addition, it can be arbitrarily selected from known core-sheath type composite forms such as a multi-core type having a plurality of cores. In addition, the area ratio of the magnetic component in the cross section of the fiber is usually 5 to 80%, particularly preferably 10 to 50%, from the viewpoint of the strength and the magnetic properties of the fiber.

The thickness of the magnetic composite fiber of the present invention is also arbitrary, but is usually
About 0.1 to 50 denier, particularly about 5 to 30 denier is often used.

In the present invention, the fabric composed of magnetic composite fibers is a plain weave using the composite fibers in a so-called warp and / or weft.
Various fiber structures such as woven fabrics such as twill weave and satin weave, knitted fabrics such as flat knitting, rubber knitting, and pearl knitting, woven and knitted fabrics having a similar structure, and nonwoven fabrics produced by a known method are included.
Of course, the composite fiber and other (non-magnetic) fibers can be freely mixed. In this case, the mixing ratio of the magnetic composite fiber is usually 10% by weight or more, preferably 30% by weight or more, although it varies depending on the magnetic properties of the magnetic composite fiber used and the purpose of use.

The magnetization of the cloth mixed with the magnetic composite fiber of the present invention is the fourth.
As shown in the figure, the fabric was heated in a magnetic field in a direction perpendicular to the fabric surface, and the matrix polymer of the magnetic component of the composite fiber was softened or dissolved to orient the magnetic particles in the direction of the magnetic field. Cooling (while applying a magnetic field)
Perform after solidification. At this time, the magnetization pattern of the fabric is as follows.
A uniform type in which the magnetic poles on the cloth surface are the same as in FIG. 1, a stripe type in which the magnetization directions are opposite to each other at regular or irregular intervals, a lattice type as in FIG. 3, etc. Although various patterns are possible, in consideration of the continuity of the magnetic characteristics, a stripe type or a lattice type in which different poles are close to each other and in which a magnetic field is easily formed is preferable. In addition, since these molds form a magnetic field between adjacent different poles, the magnetized fabric easily adheres to an object made of a magnetic material such as cobalt. It can also be expected to form and promote blood circulation. Of course, it is also possible to form a non-magnetized portion in the fabric with each of the magnetized patterns.

In order to perform the heating magnetization as described above, the softening point or melting point of the matrix polymer of the magnetic component of the conjugate fiber is preferably at least 50 ° C. lower than that of the protective component, particularly preferably 70 ° C. or higher. This is because it is desirable that the protective component maintain a sufficient strength during the heat magnetization and orientation processing.

(Examples) Hereinafter, the present invention will be described specifically with reference to examples.

Example 1 Samarium cobalt (SmCo ₅ ) particles having an average particle size of 1.5 μm, a coercive force of 790 kA / m, and a residual magnetic flux density of 1.0 T are designated as MP1. A core obtained by melting and mixing 180 parts of magnetic powder MP and 20 parts of a polybutene resin “Polybutene-1M2481” manufactured by Mitsui Petrochemical Co., Ltd. having a melting point of 72 ° C., and 1.5% by weight of titanium oxide particles as a matting agent
As shown in Fig. 2, composite spinning was carried out at a composite ratio of 1/1 (volume ratio of core / sheath) using nylon 6 having a molecular weight of about 16000 and a melting point of 215 ° C in which sheath was dispersed. Spinning temperature 280 ° C and diameter 0.2
Spin out from 5mm orifice, wind up at 800m / min while cooling and oiling, and draw ratio 3.0 at 80 ° C
And subjected to a tension heat treatment on a 150 ° C. plate heater to obtain a drawn yarn Y1 of 240 denier / 10 filaments.

Using the drawn yarn Y1 as a warp and a weft, a plain fabric P1 having a gauge of 50 yarns / inch was prepared.

The woven fabric P1 was magnetized alternately with a width of 2 cm with a non-magnetized layer having a width of 0.5 cm interposed therebetween in the same manner as in FIG. A magnetic field of 700 kA / m was applied in an atmosphere at a temperature of 100 ° C., heated and magnetized for 5 minutes, and cooled to room temperature with the magnetic field applied. The resulting woven fabric had a magnetic flux density of 0.030T.

(Effects of the Invention) As described above, a fabric composed of fibers having a high flexibility and having excellent magnetism can be easily obtained by the present invention. In addition, the magnetic fabric of the present invention utilizes various magnetic properties such as detachable fasteners using magnetic force, health clothing such as socks, gloves, belly bands, stockings, electromagnetic wave shielding articles, and magnetic particle collection filters. Applications can be expected.

[Brief description of the drawings]

FIG. 1 to FIG. 3 are examples showing the magnetized pattern of the magnetic cloth of the present invention. 4 and 5 are schematic views showing a method of magnetizing the magnetic fabric of the present invention, and FIGS. 6 and 7 are cross-sectional views of magnetic composite fibers that can be used in the present invention. 1: Cloth composed of magnetic composite fiber, 2: Magnetic component of magnetic composite fiber, 3: Protection component of magnetic composite fiber.

Claims (1)

(57) [Claims] A thermoplastic polymer containing magnetic particles is used as a core component, a fiber-forming polymer is used as a sheath component, and the softening point or melting point of the core component is at least lower than that of the sheath component.
A magnetic composite fiber composed of a material having a temperature lower by 50 ° C. is used as a constituent yarn, and is magnetized in a direction perpendicular to the cloth surface at a temperature higher than the melting point or softening point of the core component and lower than the melting point or softening point of the sheath component. Characteristic magnetic cloth.