JPH04238952A - Conductive color particle and conductive decorative sheet using the same particle - Google Patents

Abstract

PURPOSE:To provide conductive color particles with which a conductive decorative layer formed of a micromosiaclike pattern is easily formed without losing decorative properties and a conductive sheet wherein a decorative layer is formed by using the conductive color particles. CONSTITUTION:Particles 20 is prepared such that conductive fibers 22 having an average fiber diameter of 1-1000mum, an average fiber length of 0.1-10mm, and an average aspect ratio of 5-1000 are added in colored synthetic resin particles with an average grain size of 0.1-10mm. A sheet is formed such that a conductive decorative layer having a micromosiaclike pattern is formed of the particles 20. The two ends of the conductive fiber 22 are exposed from the surface of the particle 20, or a plurality of fibers are entangled together and are brought into contact with each other and extended through the particle 20 like a single fiber, and energization of the particle 20 is reliably ensured. In a sheet formed of the particles 20 effecting reliable energization, contact between the conductive fibers 22 in the particle 20 and a conductive material mixed in a packing material is ensured, and energization between the surface and the back of the sheet is excellently and reliably ensured.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to conductive color particles that are suitably used in forming a conductive decorative layer consisting of a fine mosaic pattern, and the decorative layer formed using the particles. Regarding conductive sheets.

0002

[Prior Art] Sheets made of electrically conductive synthetic resin (hereinafter referred to as "conductive sheets") are used to prevent problems caused by static electricity (such as explosions, dust adhesion, etc.) in hospital operating rooms and computer rooms. It is often used as flooring and wall materials to prevent malfunctions (malfunctions, etc.).

Conventionally, as shown in FIG. 3, this conductive sheet is made of a nonwoven fabric, woven fabric, knitted fabric, etc. made of glass fiber, synthetic fiber, natural fiber, etc., coated with a conductive synthetic resin to which a conductive material is added. Alternatively, synthetic resin particles (chips) 10 which also have conductivity are spread and fixed on the backing material 1 made of an impregnated sheet material or a sheet material prepared from the conductive synthetic resin, and the microscopic A decorative layer 2 has been developed in which a mosaic pattern is formed. The above-mentioned conductive chip 10 is generally one to which highly conductive carbon black powder is added.

0004

[Problems to be Solved by the Invention] In the case of a conductive sheet, it is necessary to have conductivity from the surface of the micro mosaic pattern layer 2 to the back surface of the backing material 1. It is necessary to add the above carbon black powder to the synthetic resin chip 10 as well. Therefore, in the conductive sheet, even the fine mosaic pattern layer 2 is tinged with blackish gray or black due to the carbon black powder, and the decorative properties are completely lost.

[0005] As a countermeasure to this problem, the above-mentioned mosaic pattern layer has been created by using a mixture of chips to which carbon black powder is added and synthetic resin chips that are made of a light-colored conductive material and can be colored as desired. (Japanese Unexamined Patent Publication No. 63-112777), or by forming a surface layer of a colored thermoplastic resin containing a light-colored conductive material on the surface of colored synthetic resin particles, a mosaic pattern layer can be created. Technology has been developed to form

However, in the former case, in addition to the need to prepare two types of chips, conduction from the sheet surface to the backing material is ensured only by the conductive material mixed in the chip. This requires advanced mixing technology (requiring mixing in a completely uniform state and strict adjustment of the mixing amount), and the sheet manufacturing process is complicated.

[0007] In the latter case, although electrical conductivity from the sheet surface to the backing material is sufficiently ensured, there is a concern that the manufacturing process will become complicated due to the addition of the step of forming a surface layer of synthetic resin particles.

The present invention has been made in consideration of the above points, and it is possible to easily form a conductive decorative layer having a micro mosaic pattern as described above without sacrificing its decorative properties. An object of the present invention is to provide conductive color particles that can be used as a decorative material, and a conductive sheet formed by forming a decorative layer using the particles.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the inventors of the present invention have made extensive studies and found that if a fibrous material of specific dimensions is used as a conductive material to be added to synthetic resin particles. The present invention was developed based on the finding that it is not only possible to color the particles as desired, but also to easily and reliably ensure conduction from the front surface to the back surface of the sheet.

That is, the present invention provides (1) an average particle size of 0.
Colored synthetic resin particles of 1 to 10 mm with an average fiber diameter of 1 to 10 mm
1,000 μm, an average fiber length of 0.1 to 10 mm, and an average aspect ratio of 5 to 1,000 conductive color particles, and (2) having conductivity. The object of the present invention is to provide a conductive decorative sheet, characterized in that the conductive color particles described above are adhered to a backing material.

[0011] In the present invention, as the resin constituting the colored synthetic resin particles, a thermoplastic resin constituting a chip which is commonly used when forming this type of decorative layer can be used. Specifically, polyvinyl chloride, vinyl chloride-based resins such as copolymer resins of vinyl chloride and ethylene, vinyl acetate, vinyl ether, maleic ester, (meth)acrylic acid, (meth)acrylic ester, acrylonitrile, urethane, etc. Resin, vinyl acetate resin, polyethylene, polypropylene, acrylic resin, ethylene-vinyl acetate copolymer resin, urethane resin, ABS resin, AS resin,
Examples include homopolymers or copolymers of polybutylene terephthalate, polyethylene terephthalate, 6-nylon, 6,6-nylon, polyacetal resin, polysulfone, polyethersulfone, polyphenylene oxide, etc. These resins may be used alone or in combination. and can be used.

[0012] The above thermoplastic resin also contains a plasticizer,
Coloring agent, filler, stabilizer, lubricant, foaming agent as required,
Additives commonly used in chips of this type, such as fungicides, are added.

[0013] Examples of the plasticizer include dioctyl phthalate, dibutyl phthalate, butyl benzyl phthalate,
In addition to the general plasticizers commonly used in the above chips, such as dioctyl adipate, diisononyl phthalate, and tricresyl diphosphate, DAP, acrylic monomer,
Reactive plasticizers such as acrylic oligomers, tributoxyethyl phosphate, butyl diglycol adipate, Sansocizer C-1100 (trade name manufactured by Shin Nihon Rika)
, AM-801B (Sekisui Chemical product name), AM-801
Antistatic plasticizers such as A (trade name, manufactured by Sekisui Chemical Co., Ltd.), secondary plasticizers such as dodecylbenzene derivatives, etc. can also be used. The amount of plasticizer added is preferably about 10 to 100 parts by weight per 100 parts by weight of the above thermoplastic resin.

[0014] As the above-mentioned colorant, a colorant commonly used for this type of chip is used. The amount of the colorant is appropriately selected depending on the type of colorant and the desired coloring state.

[0015] The above-mentioned fillers include, for example, calcium carbonate, clay, silica, shirasu balloons, glass balloons, wood powder, cork powder, etc. for increasing the volume, as well as fillers for the purpose of imparting wear resistance and anti-slip properties. Silica sand grains, silicic acid compound grains,
Hard powders and granules such as glass powder, crushed ceramic particles, carborundum, and alundum, as well as inorganic short fibers such as glass fiber, calcium titanate short fibers, and MOS (calcium metasilicate) short fibers, are used to provide dimensional stability. Can be used. The amount of these fillers added is 1 of the total amount of synthetic resin particles.
The content is preferably about 0 to 100% by weight.

Additives other than the above-mentioned plasticizers, colorants, and fillers, such as stabilizers, lubricants, foaming agents, and antifungal agents, are added in appropriate amounts depending on the purpose of use.

Further, in the present invention, the conductive fibers added to the colored synthetic resin particles composed of the above-mentioned thermoplastic resin, colorant, filler, and various other additives include carbon, various metals ( (titanium, gold, silver, copper, nickel, aluminum, stainless steel, iron, etc.), conductive calcium carbonate, conductive potassium titanate, fibers made of other conductive materials, glass fibers, the above inorganic short fibers, etc. Inorganic fibers or organic fibers whose surfaces are coated with the above-mentioned various metals, metal oxides, or other conductive substances are used.

The average diameter, average length, and average aspect ratio of the conductive fibers are determined in relation to the particle size of the synthetic resin particles, and in the present invention, the average particle size of the particles is 0.
1 to 10 mm, average diameter 1 to 1000 μm, preferably 5 to 100 μm, average length 0.1 to 10 mm, preferably 0.5 to 5 mm, average aspect ratio 5 to 1000
Preferably it is 10-200.

That is, the average diameter of the conductive fibers is 1 μm.
If it is less than 1,000 μm, the handling properties of the fibers will deteriorate, resulting in inconvenience in terms of work. On the other hand, if it exceeds 1000 μm, the appearance of the particles of the present invention having the above-mentioned average particle size will be impaired (particularly if the fibers are black or Dark colors make it difficult to impart the desired color to the particles of the present invention) and adversely affect the decorativeness of the fine mosaic pattern layer.

[0020] Furthermore, the average length of the conductive fibers is 0.1 mm.
If it is less than 10 mm, the contact between the fibers within the particles of the present invention having the above-mentioned average particle size will be insufficient, and it may not be possible to obtain the desired conductivity.On the other hand, if it exceeds 10 mm, the fibers will become entangled. During granulation of the particles of the present invention, fluidity is inhibited, making it extremely difficult to obtain particles having the above-mentioned average particle size. Even if granulation is possible, the appearance of the particles of the present invention will be impaired due to the fibers intertwined in multiple layers (particularly in the case of black or dark colored fibers).

[0021] If the average aspect ratio is within the above range of fiber diameter and fiber length, no skill is required to use the mixing and granulation means used when preparing this type of chip. The conductive fibers can be uniformly mixed and granulated in a good condition by ordinary operations without requiring special care. As a result, the particles of the present invention not only exhibit excellent conductivity, but also have properties suitable for forming a fine mosaic pattern layer.

The amount of conductive fibers having the above-mentioned fiber diameter, fiber length, and aspect ratio is appropriately selected depending on the desired resistance value, but is generally about 0.3 weight of the total amount of the above-mentioned synthetic resin particles. % or more is preferable.

The particles of the present invention are granulated by adding the above-mentioned materials into, for example, a high-speed rotary blade mixer, other conventional high-speed stirring mixer, ribbon blender, or the like, and using a conventional granulation method.

The backing material for the sheet of the present invention may be, for example, a foamed or non-foamed sheet of conductive synthetic resin added with a conductive material, glass fiber, organic fiber,
The above-mentioned conductive material can be added to non-woven fabrics, woven fabrics, knitted fabrics, etc. made of fibers such as pulp, or by mixing these fibers with conductive fibers of the same material as the conductive fibers added to the particles of the present invention. A conductive base material coated with or impregnated with a synthetic resin, a cloth made at least in part of conductive fibers such as carbon fibers or metal fibers, etc. can be used.

As the above-mentioned conductive material added to the synthetic resin, the above-mentioned conductive fiber added to the particles of the present invention may be used, carbon black powder, conductive titanium oxide (the surface of the titanium oxide is (treated with Sn-Sb compounds), metals (silver, copper, nickel, aluminum,
Powder of stainless steel, iron, etc.), foil strips, etc. can also be used.

[0026] This conductive material can be in the form of powder or strips with an average particle size of about 0.1 to 1000 μm, or in the form of fibers with a diameter of about 1 to 1000 μm x a length of about 0.1 to 30 mm. , is preferable because of its ease of mixing with synthetic resins, ease of workability such as coating and impregnation after mixing with synthetic resins, sheet formation, etc.

[0027] The amount of these conductive materials to be added is appropriately selected depending on the desired resistance value, but generally they are in the form of powder or strips and are added to synthetic resins (after mixing with plasticizers, colorants, etc. to be described later). Approximately 2% by weight or more of short fibers, approximately 1% by weight of short fibers
The above is preferable.

[0028] Examples of the synthetic resin include those similar to the synthetic resins constituting the particles of the present invention described above, and these may be used alone or in combination.

[0029] Additives such as a plasticizer and, if necessary, a coloring agent, a filler, a stabilizer, a foaming agent, and a fungicide are added to these synthetic resins. As the plasticizer, the same plasticizers as those used in the particles of the present invention described above can be used. The amount of plasticizer added is appropriately selected from the range of 10 to 100 parts by weight based on 100 parts by weight of the synthetic resin, as in the case of the particles of the present invention. As colorants, fillers, and other additives, the same colorants as those used in the particles of the present invention described above can be used, and the amount of these additives to be added is selected as appropriate depending on the purpose of use. .

The sheet of the present invention is formed by scattering the particles of the present invention on the backing material, followed by heating and pressing.

[0031] At this time, the particles of the present invention may be sprayed only with particles made of the same type of material, or particles made of different materials may be appropriately combined, or particles of different colors may be dispersed as appropriate. You can also do it. As means for dispersing the particles of the present invention, a diaphragm, a hopper, a doctor blade having a notch, a feeder having intermittent supply ports, a scatterer fed by a brake roll, a spreader fed by an intaglio roll, etc. are used. The amount of spraying is not particularly limited, but is generally preferably about 500 to 2000 g/m2.

Furthermore, as the above-mentioned heating and pressing means, ordinary means used when manufacturing this type of sheet are adopted, such as ordinary embossing equipment including flat embossing, press equipment with a built-in heater, high frequency induction Examples include heating and pressurizing equipment. In particular, using a large diameter heat roll,
Pressure contact is preferably performed at a contact angle of 10 to 330°. At this time, it is of course possible to use a pressure roll with a small diameter. If this pressure roll is hard, the synthetic resin of the backing material will have a strong tendency to ooze out from the sides of the roll, reducing the quality of the product. It is preferable to use one wrapped with rubber, sponge, etc.

[0033] Furthermore, the temperature and pressure during heating and pressing will vary depending on the type of synthetic resin used in the backing material and the particles of the present invention, the type and amount of plasticizer, and the means of heating and pressing. The most suitable one is selected.

[0034] In the sheet of the present invention, for the purpose of improving dimensional stability, conductive treated glass paper, glass fiber nonwoven fabric, etc. may be laminated on the backing material, and the above-mentioned particles of the present invention may be sprinkled on this. good.

[0035]

[Operation] In the particles of the present invention, for example, as schematically shown in FIG. 1, conductive fibers 22 are mixed in the synthetic resin 21 that forms the matrix of the particles 20 of the present invention.

Since the conductive fiber 22 has a specific diameter, length, and aspect ratio, as shown in FIG.
Both ends of one fiber (see 221 in FIG. 1) are particles of the present invention 2.
The fibers are exposed on the surface of the particles 20, or several fibers are entangled with each other and come into contact with each other, penetrating the inside of the particle 20 of the present invention as if it were a single fiber, thereby ensuring conduction of the particle 20.

[0037] In the sheet of the present invention constructed using the particles of the present invention that exhibit such reliable conduction, the conductive fibers within the particles 20 do not come into contact with the conductive material mixed in the backing material. This ensures good conductivity from the front surface to the back surface of the sheet of the present invention.

Furthermore, in the case of the conductive fibers having the above-mentioned specific dimensions, the desired coloring of the particles of the present invention is not inhibited, and the decorativeness of the fine mosaic pattern layer of the sheet of the present invention by the particles of the present invention is not adversely affected. It will not affect you.

Moreover, in the case of the conductive fibers having the above-mentioned specific dimensions, it is easy to achieve a uniform mixing state with the synthetic resin that is the matrix of the particles of the present invention, so that unlike the conventional case described above, the conductive fibers This eliminates the need for advanced mixing techniques for conductive materials, which are necessary to ensure conductivity in the sheet.

As a result, the manufacturing process of the particles of the present invention, and by extension the manufacturing process of the sheet of the present invention, becomes simple.

Furthermore, since the particles of the present invention are uniformly mixed with conductive fibers of specific dimensions, the sheet of the present invention obtained using the particles has rigidity and excellent load-bearing properties. Become something.

[0042]

[Example] Example 1 (Preparation of particles of the present invention) The composition shown in Table 1 was granulated by heating and stirring with a high-speed stirring blade mixer (Henschel mixer), and then immediately cooled to produce conductive color particles of the present invention. Obtained.

[0043]

[Table 1]

When the resistance values of some of the color particles of the present invention obtained as described above were measured, the resistance values were within the range of 104 to 105 Ω, and it was confirmed that they had excellent conductivity. Ta. The above color particles were sieved to collect particles having an average particle size of 2 mm.

(Preparation of the sheet of the present invention) A glass fiber-mixed nonwoven fabric (50 g/m2) was coated and impregnated with vinyl chloride paste having the composition shown in Table 2 in an amount of 1000 g/m2, and after the paste was gelled, the above-mentioned Conductive color particles were sprayed using a doctor blade in an amount of 1100 g/m2.

[0046]

[Table 2]

[0047] Next, after heating through an oven heated to 150°C and subsequently heating with a far infrared heater,
Immediately, the backing material, the conductive color particles of the present invention, and the conductive color particles of the present invention were fused together by pressure bonding using a cooled flat embossing machine to obtain a conductive sheet of the present invention.

FIG. 2 schematically shows the conductive sheet of the present invention thus obtained. In FIG. 2, reference numeral 1 denotes a backing material, and on the backing material 1 was formed a decorative layer 2 consisting of a fine mosaic pattern made of conductive color particles 20 of the present invention. Further, the conductive sheet of the present invention is
It had excellent electrical conductivity with a resistance value of 104 to 106 Ω based on the electrostatic safety guidelines of the Industrial Safety Standards Institute of the Ministry of Labor.

Example 2 (Preparation of particles of the present invention) Conductive fibers having an average diameter of 10 to 15 μm and an average length of 0.5 to 0
．． Conductive color particles of the present invention were prepared in the same manner as in Example 1, except that conductive potassium titanate fibers having a diameter of 8 mm and an average aspect ratio of 35 to 80 were used. When the resistance values of some of these conductive color particles were measured, they were 104~
It was confirmed that the resistance value was within the range of 105Ω, and that it had excellent conductivity.

Example 3 (Preparation of particles of the present invention) Conductive titanium oxide (trade name: ECT manufactured by Titan Kogyo Co., Ltd.) was used as a coloring agent.
Conductive color particles of the present invention were prepared in the same manner as in Example 1 except that R-72) was used. When the resistance values of some of these conductive color particles were measured, they were 103 to 105.
It was confirmed that it exhibited a resistance value within the range of Ω and had excellent electrical conductivity.

Example 4 (Preparation of sheet of the present invention) Example 2
A conductive sheet of the present invention was prepared in the same manner as in Example 1, except that equal amounts of the particles of the present invention prepared in Example 3 were used. This conductive sheet has a resistance value of 104 based on the static electricity safety guidelines of the Industrial Safety Standards Institute of the Ministry of Labor.
It was confirmed that it had excellent conductivity of ~106Ω.

[0052]

Effects of the Invention As detailed above, according to the particles of the present invention, since the conductive fibers mixed therein have specific dimensions, one fiber or several fibers may become entangled or come into contact with each other. The fibers penetrate through the particles of the present invention and are exposed on the surface of the particles of the present invention as if they were a single fiber, thereby ensuring the conductivity of the particles.

Moreover, according to the particles of the present invention, conductive fibers of a specific size can be easily and uniformly mixed into the synthetic resin, making it easy to ensure the conductivity of the particles of the present invention.

[0054] Furthermore, according to the sheet of the present invention using the particles of the present invention, the conductive fibers in the particles of the present invention are in reliable contact with the conductive material mixed in the backing material. To ensure good and reliable conduction all the way to the back side.

Furthermore, in the case of the conductive fibers having the above specific dimensions, the desired coloring of the particles of the present invention is not inhibited, and the decorativeness of the fine mosaic pattern layer of the sheet of the present invention by the particles of the present invention is adversely affected. It will not affect you.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the action of particles of the present invention.

FIG. 2 is an explanatory diagram showing an embodiment of the sheet of the present invention.

FIG. 3 is an explanatory diagram showing an example of a conventional conductive sheet having a micro mosaic pattern.

[Explanation of symbols]

1 Backing material 2 Decorative layer 20 Particles of the present invention

Claims (2)

[Claims] Claim 1: Colored synthetic resin particles with an average particle diameter of 0.1 to 10 mm, an average fiber diameter of 1 to 1000 μm, an average fiber length of 0.1 to 10 mm, and an average aspect ratio of 5.
Conductive color particles characterized by adding conductive fibers of ~1000. 2. A conductive decorative sheet comprising the conductive color particles according to claim 1 attached to a conductive backing material.