JPS63283906A - Wood flour material - Google Patents

Abstract

PURPOSE:To provide a material which possesses conductivity and a fine look as lumber and is light in weight, by containing wood flour, a powdery conduc tive material and synthetic resin as components. CONSTITUTION:Wood flour, metallic powder and synthetic resin are weighed so that a weight ratio becomes 100:200:10 (process S1). Then water-resistant treatment and chemical treatment are performed to the wood flour by making use of a silicone repellent (process S2). The wood flour to which water-resistant treatment and chemical treatment have been performed is kneaded with the metallic powder and synthetic resin in a process S3. Cold press molding of this kneaded matter is performed at pressure of 50-80 kgf/cm<2>. A material obtained in this manner possesses favorable electric field shielding properties and magnetic field shielding properties and is superior in magnetic wave absorp tion properties. As the material is capable of performing electroplating, it can be used for manufacturing of a picture frame and Buddist altar fittings.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to materials, and more particularly to materials manufactured by pressure-molding a large amount of wood flour into a desired shape, that is, wood flour materials. .

[Prior art] In recent years, in order to remove electromagnetic interference from electronic equipment such as computers and prevent static electricity from forming on electronic equipment, doors, knobs, desks, flooring, wooden molds, etc., materials that do not have conductivity have been developed. There is a growing demand for this. In order to meet these demands, attempts have been made to attach metal plates or conductive fibers to the surface of wood. However, since the work process required for attaching the conductive substance is complicated, the production cost increases and the appearance of the wood deteriorates.

Also, materials are known that are made by kneading synthetic resin and metal powder to give them electrical conductivity, but it is difficult to uniformly disperse the metal powder in the synthetic resin, so it is difficult to give uniform electrical conductivity to the material. Moreover, the weight of the product was large.

[Object of the Invention] Therefore, the object of the present invention is to provide a new material that is electrically conductive, can be easily produced, is lightweight, and is structured so as not to impair the aesthetic appearance of wood. The goal is to provide the following.

[Structure of the Invention] The wood flour material of the present invention contains wood flour, a powdery conductive material, and a synthetic resin as composition components.

[Operations and Effects of the Invention] The wood flour material of the present invention has a powdery conductive material as a component thereof, and the conductive material imparts good conductivity to the entire material. Since it contains wood flour as a component, the powdered conductive material comes into contact with the wood flour fibers in a tightly intertwined state, giving uniform conductivity to the entire material. Therefore, if the wood powder material of the present invention is used, electromagnetic interference from electronic equipment can be removed, and fittings such as doors, etc.
It can remove static electricity from wooden molds, flooring materials, etc. Moreover, it is possible to plate wood powder materials by utilizing their conductivity. Further, since the conductive material is present in the wood flour material as a powder, the wood flour material has the aesthetic appearance of wood. The wood flour material of the present invention contains a large amount of wood flour as a component, and the material as a whole is as lightweight as wood.

Furthermore, in addition to wood flour, powdered conductive materials and synthetic resins (
The wood flour material of the present invention improves various physical properties such as abrasion resistance, water resistance, and fire resistance due to the fact that it has as a composition component a material that functions as a binder between wood flour and a conductive material. I can do things.

In connection with these cumulative effects, if the wood flour material of the present invention is used, the added value of picture frames, Buddhist altar fittings, etc. will be improved, and there will be the possibility of developing new products in various other fields as well. .

[Preferred Embodiment] The wood flour material of the present invention is preferably manufactured by kneading wood flour, a synthetic resin, and a powdery conductive material, and molding the mixture by cold pressing.

Various types of wood flour can be used, but commercially available 80 to 100 mesh cedar or pine is suitable. (The moisture content of wood is preferably 10% or less, especially 5% or less.) There are a wide variety of conductive materials such as metal powder, conductive paint, metal foil, metal fiber, carbon fiber, glass fiber, ceramic, and ferrite. Although a wide variety of materials can be used, nickel or copper are particularly preferred.

These conductive materials are preferably in the form of powder or granules of 100 to 400 meshes.

Various synthetic resins can be used, such as acrylic, polyurethane, phenol, and urea resins, and epoxy resins, which are plastic and harden at room temperature, are particularly preferred.

After kneading wood flour, powdered conductive material, and synthetic resin, 50
It is preferable to cold-press the molded wood flour material at ~80 sqf/-, and the specific gravity of the molded wood flour material is preferably 1.8 to 2.0. At a pressure below 50 kgf/-, the molded wood flour material The electromagnetic wave shielding properties of wood tend to be unevenly distributed in a specific frequency range, and on the other hand, when compressed at a pressure exceeding 80 kgf/ai, the appearance of the molded material loses the aesthetic appearance of wood. This is because the material becomes bulky and the weight of the material becomes heavy.

Furthermore, it is preferable to subject the wood flour to water resistance treatment and chemical treatment using a silicone-based water repellent.

This is because by subjecting the wood flour to such a treatment, the conductive material will be uniformly dispersed during kneading, and the conductivity of the molded wood flour material or its product will also be uniform.

[Example] Examples of the present invention will be described below.

In this example, the wood flour was made from commercially available cedar and pine powder with a particle size of 8.
A mesh of 0 to 100 is used.

As mentioned above, it is particularly preferable that the moisture content of wood flour is 5% or less, but most of the composition of wood flour (approximately 55%) is cellulose, and excessive drying will cause dust due to heat abrasion, foreign matter, etc. Since there is a risk of explosion, a commercially available wood flour with a moisture content of 8 to 10% is used in this example.

Next, as the conductive substance in this embodiment, nickel or copper metal powder is used. The metal powder particles are finer than the wood powder particles and are 200 mesh. Moreover, the purity is the same as that of commercially available fine powder for chemical use.

As the synthetic resin used as a binder between the wood powder and the metal powder, an epoxy resin is used in this embodiment, and the epoxy resin has a plastic curing property at room temperature.

Next, the manufacturing process of the wood flour material according to this example will be explained with reference to FIG.

First, the above wood powder, metal powder, and synthetic resin were mixed in a weight ratio of 100:2.
00:10 (Step S1), and subjected the wood flour to water resistance treatment and chemical treatment using a silicone rice bowl water agent (Step S2), wood flour subjected to water resistance treatment and chemical treatment,
The metal powder and synthetic resin are kneaded in step S3. In step S3, the metal powder is uniformly dispersed in the mixed material,
The molded article is treated to have uniform conductivity. (still,
It has been found that by chemically treating the powder in step S2, the metal powder can be uniformly dispersed.

) After mixing, the kneaded product is cold-pressed at a pressure of 50 to 80 kgf/d.

Here, when the pressure is 50 kIrf/-, the specific gravity of the molded product is approximately 1.8, 1.79 for nickel, and 1.79 for copper.
83), and on the other hand, when the pressure is 80 kgf/J, it is about 2.0, for nickel it is 2.0, and for copper it is 2.1.
).

Below, various physical properties of the wood flour material obtained in this example will be explained. The samples used to measure the physical properties were 2
These are ten flat members having dimensions of 00BmX200maX3~3, 5Bm.

(1) Conductivity The surface resistance of the four corners and center of the above sample was measured using a tester (electrical resistor) to examine the conductivity.

The results are as follows.

Nickel: 10° to io' Ω Copper: 10° to 10 4 Ω The samples according to the present example showed uniform and good conductivity for both nickel and copper.

(2) Electric field shielding properties The shielding properties of the sample in the near electric field were measured using video photographs, and the necessary analyzes were performed from the measured video photographs. Figures 2A to 2D are obtained from the measurements and analyses. Figure 2A is for nickel metal powder with a specific gravity of 1.8, and Figure 2B is for nickel metal powder with a specific gravity of 2.0. If so, Figure 2C shows the case where the specific gravity is 1.8 and contains copper metal powder, and Figure 2B shows the case where the specific gravity is 2.0 and contains the copper metal powder.

In Figures 2A to 2D, the horizontal axis is frequency (MH2)
The left side of the figure shows higher frequencies, while the vertical axis shows shielding performance (dB), and the lower side of the figure shows better shielding performance (dB).
B value is large.

Generally, the minimum allowable value for electromagnetic wave shielding at frequencies of 30 to 100 MH2 is 30 dB (for example, the electromagnetic radiation regulations of the US Federal Communications Commission FCC). 2A to 2D, the dB value of the sample of this example can be set to the minimum allowable value (30 dB).
B) The frequency range when the above is achieved is as follows.

Nickel (specific gravity 2.0)...100-800Hz Copper (specific gravity 1.8)...100-500Hz2 Copper (specific gravity 2
．． 0)...100100-9O0 That is, each sample effectively shielded the electric field in the above frequency range.

(3) Magnetic field shielding property As in the case of electric field shielding property, the shielding property of the sample against the near magnetic field was measured using video photographs, and the necessary analysis was performed, and the results are shown in Figures 3A to 3D. has been done.

This is shown in FIGS. 3A-3B. Figure 3A~
Figure 3D is a drawing similar to Figures 2A to 2D; Figure 3A has a specific gravity of 1.8 and contains nickel metal powder, and Figure 3B has a specific gravity of 2.0 and contains nickel metal powder. In this case, Fig. 3C shows the case where the specific gravity is 1.8 and contains copper metal powder, and Fig. 3D shows the case where the specific gravity is 2.0 and contains the copper metal powder. The vertical axis represents the magnetic field shielding property (dB value), and the horizontal axis represents the frequency (
MH2).

As in the case of electric field shielding, the allowable minimum value can be set to 30 dB in the case of magnetic field shielding as well. From Figures 3A to 3D, the dB value of the sample of this example is the minimum allowable value (30 dB).
The range of frequencies when exceeding nickel (specific gravity 2.0)...200 to 400 Hz, copper (specific gravity 1.8>...300 to 400 MHz, copper (specific gravity 2.0)...200 to 600 MHz, in other words. For example, each sample effectively shields the magnetic field in this frequency range.

(4) Deformation over time was extremely small for all samples, and was a value that would not cause any practical problems.

(5) Figures 4A and 4B show the microstructure of the cross-section of the sample used for microscopic structure measurements. Figures 4A and 4B are micrographs of a sample containing nickel metal powder as a component. Yes, 4th A
The magnification of the figure is 1000x, while the magnification of Figure 4B is *'o
In Figures 4A and 4B, which are multiplied by o o, the fibers of the wood flour (the black part in the figure) have a roughly oblong shape;
Numerous saw-like irregularities of various sizes can be observed on its surface. It can be seen that the metal powder (fine nickel powder: white part in the width of the drawing) penetrates into the uneven parts of the wood powder, and the metal powder overlaps to form 81 fibers. The kudzu synthetic resin that functions as a binder between the wood powder and the metal powder is thought to be the circular gray part in the figure.

From these microscopic photographs, it is understood that the powdered conductive material (metal powder) takes the form of long fibers in the molded product, giving the molded product uniform and good electrical conductivity.

(6) It was found that the samples of Examples also have excellent electromagnetic wave absorption properties.

[Summary] According to the present invention, a new material is provided that has a low manufacturing cost, is lightweight, has a good shape, has uniform conductivity, and has the aesthetic appearance of wood. This new material has good electric field shielding properties, magnetic field shielding properties, and excellent electromagnetic wave absorption properties. Furthermore, the new material of the invention can be electroplated due to its good electrical conductivity.

Due to these various features, the present invention can be expected to improve the added value of products that utilize conductivity (for example, picture frames, Buddhist altar fittings, etc.) and expand the use of wooden products.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the manufacturing process of the wood flour rope material of the present invention, Fig. 2A, Fig. 2B, Fig. 2C, and Fig. 2D are diagrams showing the electric field shielding properties of the material, Fig. 3A, Fig. 3B. Figure, Figure 3C, Figure 3D
The figure shows the magnetic field shielding property of the material, and FIGS. 4A and 4B show microscopic photographs of the cross section of the material. Patent Applicant Japan Sewing Machine Table Industry Association Figure 2A Nickel Specific Gravity 1.8 0' 500 1000-MHz Figure 2B Nickel Specific Gravity 2, O Q 500 1000-M
Hz Figure 2C Copper Specific Gravity 1.8 - 1 Hz Figure 2D 0' 500
100G--1-■L Fig. 3A Hz Fig. 3B o soo
Too. -1---MHz Figure 3C Steel Specific gravity 1.8 o soo too. -MH2 Figure 3D W (z Figure 4A 1000x No. 48II 2000x 7, Contents of amendment Procedural amendment (method) % formula % 1, Indication of case Patent application No. 119130/1982 2, Title of invention Hydration Material 3: Relationship with the person making the amendment Applicant address: 2-11 Sumiyoshi-cho, Shinjuku-ku, Tokyo Name: Japan Sewing Machine Table Industry Association and one other director: Mori
Shigeru 4, Agent: 105 Address: 62-13-3-5 Nishijin I, Minato-ku, Tokyo
Date of the amendment order: July 1, 1985 (Delivery date: July 28) First, amend ``a microscopic photograph of a cross section of the material'' to ``a microscopic photograph showing the shape and particle structure of fibers in a cross section of the material.''

Claims (1)

[Claims] A wood flour material characterized by containing wood flour, a powdery conductive material, and a synthetic resin as composition components.