JP3414767B2 - Wood material with magnetic properties - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden material having magnetic properties. More particularly, this invention relates to an electro equipment, measuring instruments, audio equipment, it relates to new wood material having a useful magnetic properties in their various facilities. 2. Description of the Related Art In recent years, with the development of wood processing technology, various types of processed wood such as plywood, laminated wood, and particle board have been developed, and have various properties such as strength, waterproofness, and heat resistance. In order to satisfy various uses by the improvement, practical use of a new high-value-added wood material by compounding with a resin or the like has been promoted, including its composition and structure. [0003] With the development of technology, plywood and the like, which combine a conductive material for preventing static electricity, have appeared. With the development of such high-value-added wood materials, it is expected that even more useful materials will be provided while making use of the easy-to-use and natural feel of the wood materials. Under such circumstances, realization of a new functional material by a combination of a wooden material and a magnetic material is desired. In fact, in recent years, electronic devices and information devices have been rapidly introduced into offices, schools, homes, and the like, and the appearance of magnetic wood having magnetic and electrical characteristics has also been observed in furniture and walls in homes and the like. Is also required. However, magnetic materials such as iron and cobalt and ceramic materials such as ferrite have been generally used as materials having magnetic properties so far, and when these magnetic materials are used for furniture and the like, they have a soft touch. Was not a desirable material because it was hard, inorganic and cold. Accordingly, the present invention overcomes the drawbacks of the conventional magnetic materials, and is essentially a non-magnetic fibrous structure made of a high molecular substance such as cellulose or lignin. Moreover, it is an object of the present invention to provide a new high-functional wood material having a magnetic property imparted thereto while utilizing the texture of the material. SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by providing a harunire, a honoki and a yachi.
Infiltrate magnetic fluid into any of the hardwoods of the duck,
A wood material that has been injected or coated and has a frequency of 20
A wood material having magnetic characteristics characterized by no apparent decrease in magnetic permeability around 0 kHz . The magnetic fluid is essentially different from a conventionally known particle fraction type magnetic material, and exists as a liquid fluid in which fine particles of oxidative or nitride metal form a fine particle colloid structure together with a developing solvent. Examples of such a magnetic fluid include, for example, a magnetic fluid comprising iron nitride-based fine particles, a surfactant, and a liquid medium. Means for infiltration, injection, and application may be selected according to the use and characteristics of the material, and these may be applied alone or in an appropriate combination. Also,
The infiltration and injection may be performed under any of reduced pressure and pressurized conditions, and the wood material of the present invention can be obtained by these conventionally known materials and techniques in these means and in application. According to the present invention, a wood material having magnetic properties that is inexpensive, versatile, and easy to handle can be manufactured.
Since this wood material has the soft sensation and feel of wood, it does not feel uncomfortable even when used at home, etc., and it does not break the conventional furniture-like image. Widely used as etc. More specifically, for example, as a magnetic shield material for generating a high-frequency magnetic field, a high-frequency magnetic field is applied to a storage case board material of a magnetic information memory such as a floppy desk, a board material of an information communication monitor TV device, or a magnetic wood board. Since the magnetic wood portion is heated by this, surface heating can be performed, so that it is considered to be effective as a material for floor heating and the like. [0008] Wood has a fibrous structure and is composed of a high molecular substance such as cellulose or lignin. Therefore, it is considered that a large number of the magnetic fine particles in the absorbed magnetic fluid are disposed in a thin pipe such as a conduit or a branch pipe, or in a fine crack existing in a wooden material. From this, it is considered that the woody material of the present invention has relatively good magnetic characteristics even in high-frequency excitation because a thin wire device is manufactured. Hereinafter, the present invention will be described in more detail with reference to examples. EXAMPLE Production of Magnetic Wood Material The shape of the wood material is a round bar shape and the length is about 30 ± 0.8.
mm and a diameter of about 10.35 ± 0.6 mm. As for the type, honoki, harunire, kiri, and yachidamo (all hardwoods) were selected as those that easily penetrate the magnetic fluid. The magnetic wood was manufactured by three kinds of manufacturing methods: a dipping method, a vacuum injection method, and a coating method. In the immersion method, the magnetic fluid is immersed in the sample by immersing the sample in the magnetic fluid, and the immersion time (immersion time t _s ) is one.
Day, day 3, day 5, day 7, day 9 and day five. In addition, as shown in FIG. 1, the reduced pressure injection method forcibly penetrates (injects) a magnetic fluid into a wood sample using a vacuum pump, and the injection time (injection time t _v ) is reduced. 5 minutes, 1
There were four ways: 0 minutes, 15 minutes, and 20 minutes. In the coating method, a magnetic fluid was applied to the sample surface. For the immersion method and the reduced pressure injection method, four magnetic wood materials were prepared for each immersion time t _s , injection time _tv , and type of wood sample.
A book sample was prepared. Apparent Magnetic Permeability of Magnetic Wood Sample Measurement coils were placed on both ends and the center of the sample manufactured by the above-described manufacturing method as shown in FIG.
The self-inductance (L _{L1 to} L _L2 , L _R1
ＬL _R4 , L _C1 ＬL _C4 ) were measured. This gives the average value of the apparent permeability of each part of the sample (both ends of the sample:
μ _app.BS , central part: μ _app.C ). The size and dimensions of the measuring coil were as follows. Coil inner diameter, approx.
10.60mm, coil width, about 3.7mm, sample size 30 ± 0.8mm
, 10.35 ± 0.6mm. The frequency f _MC is 100k
Hz and the current I _MC were 7 mA. FIG. 3 shows the apparent magnetic permeability of a sample manufactured by the reduced pressure injection method. As shown in the figure, it was found that Harunire showed higher values in both μ _app.BS and μ _app.C than the other three types. Similar results were obtained for other production methods. It was also found that the difference in the apparent magnetic permeability due to the injection time t _V was hardly observed. This means that the immersion time t _S also applies to the immersion method.
The same was confirmed for. Next, deviation coefficients η _Bs , η _C (%) of the apparent magnetic permeability as coefficients indicating how much the value of the apparent magnetic permeability of each part of the sample is different from the average values μ _app.BS and μ _app.C. Was defined as follows. The apparent magnetic permeability deviation rates η _Bs , η _C = [(maximum apparent magnetic permeability−minimum apparent magnetic permeability) / average apparent magnetic permeability μ _app.BS , μ _{app. C} ] x 100 (%). FIG. 4 shows the deviation rate of the apparent magnetic permeability of the sample manufactured by the reduced pressure injection method (both ends of the sample: η _Bs , center: η _C ). As shown in FIG. 4, it was confirmed that honoki had the largest variation in apparent magnetic permeability. The same was clarified in the case of the immersion method. On the other hand, it was found that the variation between drill and yachidamo was smaller than those of the other two types. FIG. 5 shows the apparent magnetic permeability μ of the central portion of a sample in which honoki and kiri were produced by three production methods, respectively.
_This shows the frequency characteristics of _app.C. F _MC in Magnolia obovata from the figure it can be seen that decreases linearly little by little for any manufacturing method in the range of 10 kHz to 1 MHz. Similar results were observed for Harunire and Yachidamo. However, Kiri has f _MC = 20 for all fabrication methods
It can be seen that it sharply decreases from around 0 kHz. This seems to be a characteristic peculiar to the magnetic wood sample of Kiri. [0015] In the above sample test, Harunire showed the highest apparent magnetic permeability value among all the three types of production methods among the wood material samples. Also, from the viewpoint of the variation in apparent magnetic permeability, it can be seen that honoki has the largest variation in both the immersion method and the reduced pressure injection method, and it is difficult to produce uniform magnetic wood. On the other hand, in Kiri, the apparent magnetic permeability itself is a lower value in both the immersion method and the vacuum injection method than in honoki and harunire.
It has been clarified that a uniform magnetic wood can be produced with a small variation. Also honoki, Harunile,
The frequency characteristic of apparent permeability of Yachidamo is f _MC = 10 kHz
In the range of １1 MHz, the magnetic permeability decreases linearly little by little, whereas in the case of drilling, the apparent magnetic permeability sharply decreases at around 200 kHz. As described above, in the magnetic wooden material of the present invention, the magnetic properties such as the magnetic permeability and the magnetic flux density can be made different depending on the degree of penetration of the magnetic fluid into the surface of the wood or into the wood. The frequency characteristics of the magnetic characteristics can be easily changed. The wood has a fibrous structure made of a polymer material such as cellulose or lignis, and is considered to have almost no magnetic properties. However, since wood materials exhibit high hygroscopicity, the present invention makes use of this property and the fact that the magnetic fluid is a liquid ,
Magnolia obovata and Fraxinus Mandschurica penetrate a magnetic fluid into the unique wood material that, Note Nyuma others can fabricated wood having magnetic properties by a method of coating the fabric, which provides a new functional material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram illustrating a method for producing a magnetic wood sample. FIG. 2 is a perspective view showing an installation position of a measurement coil. FIG. 3 is a correlation diagram of an apparent magnetic permeability of a sample with an injection time. FIG. 4 is an injection time correlation diagram of deviation values of apparent magnetic permeability. FIG. 5 is a frequency correlation diagram of apparent magnetic permeability.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-37309 (JP, A) JP-A-52-125479 (JP, A) JP-A-51-44580 (JP, A) JP-A-49-479 84998 (JP, A) JP-A-51-14939 (JP, A) JP-A-64-56502 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B27K 3/00

Claims (1)

(57) [Claims] [Claim 1] Harunire, honoki and yachidamo sac
A wood material obtained by infiltrating, injecting, or applying a magnetic fluid to any of the hardwood materials, and having a frequency of 200 kHz.
A wood material having magnetic properties characterized in that there is no sharp decrease in apparent permeability before and after .