JPS61160489A - Electrically conductive floor covering material - Google Patents

Abstract

PURPOSE:An electrically conductive floor covering material that is obtained by laminating a surface sheet of a vinyl chloride resin or rubber having a specific surface resistance and a specific thickness on an electrically conductive floor-covering material of a specific surface resistance, thus having a high abrasion resistance and tear strength and enabling the material to be colored, as desired. CONSTITUTION:The objective floor-covering material is obtained by laminating a surface sheet of a vinyl chloride resin (700-1,800 polymerization degree) or rubber (such as a synthetic rubber), which has a surface resistance of 10<10>-10<13>OMEGA and a thickness of less than 2.6mm on a conductive floor-covering material with a surface resistance of 10<0>-10<8>OMEGA, preferably vinyl chloride resin. The resultant material causes no decrease in abrasion resistance and tear strength and is colored, as desired. The material is suitable as a floor-covering material in a building requiring prevention of static electricity. The conductive base material is adjusted in its conductivity to 10<0>-10<8>OMEGA by adding a conductive substance such as metallic fine powder of copper or brass powder.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a conductive flooring material suitable for floors of buildings such as clean rooms and computer rooms that require prevention of electrostatic charge generation.

BACKGROUND OF THE INVENTION There is an increasing demand for conductive flooring materials having an antistatic function for flooring materials in clean rooms, computer rooms, etc. This conductive flooring is generally made by kneading a conductive material such as conductive carbon black into a plastic flooring material or a rubber flooring material and molding the mixture into a flooring material.

Problems that the invention aims to solveIndoors, especially in work rooms where mental exertion is required, such as computer operation rooms and clean rooms where precision work is performed, it is necessary to prevent static electricity on the floor and to harmonize the color of the room from the viewpoint of occupational health. In addition, it is often necessary to add a specific color to the floor for identification.However, because of the black carbon black blended in a large amount, those kneaded with conductive carbon black, It has the disadvantage that it is not possible to obtain the required light color or any bright color, and it also reduces the abrasion resistance, tear strength and elongation required for flooring. Furthermore, materials kneaded with metal powder to impart conductivity have significantly reduced wear resistance and are not practical. The present invention provides a conductive flooring material that solves the above-mentioned drawbacks.

Means for Solving the Problems The present inventor has developed a method for laminating a non-conductive polymer sheet with a highly conductive sheet, and adjusting the thickness of the non-conductive polymer sheet to a specific thickness. It has been unexpectedly discovered that static charging on the surface of a non-conductive polymer sheet can be prevented when the temperature is lower than that, and the present invention has been completed.

The conductive flooring material according to the present invention is made of vinyl chloride J and WMII! Or rubber surface resistivity 1010-1013Ω, thickness 2
．． The surface sheet with a thickness of 6 mm or less has a surface resistivity of 109 to 10.
It is characterized by being laminated on an 8Ω conductive floor base material.

An embodiment of the conductive flooring material of the present invention will be described with reference to the drawings. FIG. 1 shows a partially enlarged sectional view in which a top sheet 1 is laminated on a conductive flooring base material 2. As shown in FIG.

The topsheet 1 is wear-resistant as a flooring material.

Made from vinyl chloride N resin or rubber (synthetic rubber and natural rubber) from the viewpoint of tear strength, cushioning properties, etc. Said vinyl chloride W! It is also possible to add a small amount of metal filler or surfactant to the rubber compound, and by adding these things, the surface resistivity of the topsheet 1 can be adjusted to 103 to 1010Ω.
It is preferable to keep it within the range of . However, if it is added until it reaches 1030 or less, the abrasion resistance, tear strength, etc. will decrease, making it unsuitable as a surface material, and if it exceeds 100, the thickness of one surface sheet must be reduced to below the necessary limit.
Surface protection function becomes insufficient. Further, the thickness must be 5 mm or less; if it is 15 mm or more, the antistatic property of the layer surface will be poor when the surface resistivity is set at the upper limit of the above range, which is contrary to the purpose of the present application. Therefore, taking into account the surface resistivity of the top sheet and the surface resistivity of the underlying conductive floor base material, the desired thickness may be set to Z 6 mm or less, and in normal cases, α3 to 5 mm. degree is suitable.

The lower layer conductive floor base material 2 has a surface resistivity of 109 to 108 Ω and is made of vinyl chloride 1llfl or rubber such as SBR, IR, EPDM, NBR, etc. suitable for flooring material, and is coated with a conductive material. is added and formed into a sheet, and the surface paper @ part is 109 to 108 depending on the amount of conductive material added.
It is adjusted to the range of Ω.

If the surface resistivity is 109Ω or more, the effect of imparting antistatic properties to the top sheet will be poor, and if it is less than 100, it will be brittle.
It has low tensile strength, tear strength, etc., and is unsuitable as a base material.

Vinyl chloride resin is preferably used for the top sheet and the conductive floor base material, and the vinyl chloride resin is made by suspension polymerization, bulk polymerization, emulsion polymerization, etc. and has a polymerization degree of 600 to 2.
For straight and copolymerized resins of 700, the preferred degree of polymerization is 700-1800. Monomers for copolymerization include ethylene, propylene, vinyl esters including vinyl acetate, acrylic esters, and vinylidene chloride.

Acrylonitrile and other commonly used comonomers can be used.

As the plasticizer added to the Mu, many known plasticizers such as phthalic acid derivatives such as DOF, phosphoric acid derivatives such as TCP, DOA, and chlorinated paraffin can be used. The amount added is 0 to 1001 parts by weight for the top sheet per 100 parts by weight of vinyl chloride N fat! parts, preferably 2
0 to 60 parts by weight, and 20 to 2 parts by weight for the lower conductive floor substrate.
00 parts by weight, preferably 40 to 90 parts by weight.

In addition, calcium carbonate, talcum clay,
Other well-known inorganic additives are usually used, and the amount added is 0 to 50 parts by weight, preferably 0 to 20 parts by weight in the case of a top sheet, based on ff1iooo parts by weight of the tree. In the case of the lower layer base material, the amount is in the range of 0 to 450 parts by weight, preferably 50 to 35 parts by weight.

Stabilizers and lubricants are commonly used tin-based ones.

Lead-based, barium/zinc-based, calcium/zinc-based.

Stabilizers such as epoxidized soybean oil, wax, lead and other metal soaps, monoglycerides, and low molecular weight polyethylene lubricants are used.

Fine metal powder or short metal fibers are blended to impart conductivity to copper and brass.

For example, in the case of fibers, conductive metal fine powders and metals such as aluminum, stainless steel, zinc, etc., have a diameter of 1 μm to 200 μm and a length of several μm to 1 Q cm, which easily cause entanglement between fibers. Although it is desirable to use metal foil, it is not added in too large a quantity because it tends to be unevenly distributed in the powder mixture. Although carbon black does not give high conductivity to metallic substances, it is sometimes used alone, and when higher conductivity is desired, it is used in entanglements of metal fibers or fine metal powder. Since insufficient defects are often formed, metal fibers and the like are sometimes used in combination to compensate for this. As the type of carbon black, one with a high strutness is preferable, but any commonly used conductive carbon black such as acetylene type or furnace type can be used. Graphite, which has a carbon structure, can also be used in the same way, and good results can also be obtained by using it in combination with other conductive substances for the underlying conductive floor base sheet.

Carbon black and gold! The blending amount of J quality varies depending on the type, but for 100 parts by weight of fat-saving material, it is in the range of 2 to 40 parts by weight, preferably 5 to 2 parts by weight.
5 parts by weight. If it is less than 5 parts by weight, the effect of imparting electrical conductivity will be poor, and if it is more than 40 parts by weight, elongation and tensile strength will decrease, making it unsuitable for the purpose of the present invention.

The thickness of the conductive floor base material is the total thickness of the surface sheet.
It is adjusted to about the same level as zo-:somm, which is commonly used as flooring material. In addition, in order to maintain dimensional stability and ease of handling as a floor material, woven fabric, non-woven fabric, etc. may be laminated on the back side, and the lamination of the top sheet and the floor base material,
This can be done by known means such as adhesion or fusion.

Function The conductive flooring material according to the present invention has the above structure,
It is thought that the llR on the topsheet penetrates through the sheet and reaches the underlying conductive layer, where it is neutralized, and with the above-mentioned configuration, it is possible to eliminate static electricity at room temperature and normal pressure (20℃, 65
RH) allows the surface resistivity of the floor material to be 1010 Ω or less, and prevents problems caused by charging phenomena on the floor surface.

The present invention will be further explained below with reference to Examples.

Example: Using vinyl chloride + 111n1 with a high degree of polymerization,
The top sheet and the conductive floor base material were extruded into sheets by changing the amounts of plasticizers, fillers, etc. added, and the surface paper trailing ratio of the top sheet and the laminated sheet of this and the conductive base sheet was 2.
The measurement was conducted under the conditions of 0"C and 65% RH.Furnace type conductive carbon black was used as the carbon black used to impart conductivity to the conductive floor base sheet.Also, a furnace type conductive carbon black was used. A total of 8 parts by weight of a heat stabilizer (barium/zinc type Eta and a lubricant (wax type)) was added to the product.

The measurement results of sheet composition and surface resistivity are as follows:
T shown in the table.

As you can see from this table, the thickness of the top sheet is z8・mm,
The m-total G of 30 mm, the surface resistivity VL is 1012 Ω or more, and the thickness of the topsheet needs to be Z6 mm or less in order to make the 1 surface resistivity O 2 10 Ω or less.

Effects of the Invention As described above, the conductive flooring material according to the present invention has good anti-static properties as described above, and the practical physical properties such as abrasion resistance and tear strength as a flooring material are taken care of by the upper layer surface sheet. Since the surface sheet does not contain carbon black, it can be given any color.It is especially suitable as a flooring material for stressful work rooms such as lean rooms and computer rooms where color harmony in the room is required. It is also particularly useful as a flooring material for areas that require bright colors for identification.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view of a conductive flooring material according to the present invention. 1... Surface sheet, 2... Conductive floor base material.

Claims (1)

[Claims] 1. Surface resistivity of vinyl chloride resin or rubber 10^1
A conductive floor material made by laminating a surface sheet with a surface resistivity of ^0 to 10^1^3 Ω and a thickness of 2.6 mm or less to a conductive floor base material having a surface resistivity of 10^9 to 10^8 Ω.