JPS61152877A - Antistatic floor covering material - Google Patents

Abstract

PURPOSE:An antistatic floor covering material having improved durability, obtained by setting an electrically-conductive layer and a substrate under the surface layer of a crosslinked polyvinyl chloride. CONSTITUTION:100pts.wt. vinyl chloride resin is blended with 30-100pts.wt. plasticizer, 0.5-5pts.wt. crosslinking agent such as dimercaptothiadiazole, etc., and heated to give the surface layer with 0.3-1.3mm thickness. The electrically- conductive layer 2 having 0.1-0.5mm thickness obtained by dispersing 50-200wt% carbon fibers, metallic fibers such as stainless, etc., into non-rigid PVC resin is thermally subjected to contact bonding to the back of the surface layer, and the electrically-conductive layer is provided with the fibrous substrate 3 having 0.5-1.5mm thickness consisting of noncrosslinking type synthetic resin and felt, to give an antistatic floor covering material wherein the electrically-conductive layer obtained by adding the electrically-conductive substance to the synthetic resin is tightly stuck to the core material layer.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applied to offices and factories in general, where electronic equipment such as computers is installed using flooring materials with antistatic properties and durability, and in particular to manufacturing electronic parts or products. This is an antistatic flooring material suitable for floors that require static electricity countermeasures, such as in factories.

(Prior Art and its Problems) The present applicant has disclosed a method for manufacturing a durable flooring material in Japanese Patent Application No. 57-66075 as a flooring material that exhibits satisfactory performance under harsh conditions in factories and the like. The above-mentioned flooring material has a thermally crosslinked PVC layer on its surface, has heat resistance and solvent resistance, and is physically excellent.

However, in recent years, there has been significant automation in factories, and many factories are required to take countermeasures against static electricity, such as by installing electronic equipment with built-in computers.In such factories, antistatic properties are essential even on the floor. It has become to.

However, with conventional anti-static treatments, it was not able to demonstrate its full functionality as a factory flooring material. For example, when an organic antistatic agent is kneaded into the surface layer, it is hygroscopic and stains easily, is easily affected by humidity, and has low antistatic properties at low humidity.Also, the antistatic agent is a liquid surfactant. Use 9: As the paper gradually decreases due to evaporation, etc., its durability is low, and its workability and physical performance also deteriorate.

Furthermore, when a conductive substance such as carbon black or metal powder is kneaded into the surface layer, the effect is semi-permanent, but the processability is poor and the physical performance is also reduced. Moreover, the surface layer mixed with carbon black or metal powder becomes dark in color, which is not preferable.

Recently, conductive plasticizers have been used as coatings, but they are expensive and even if such conductive plasticizers are added to the surface layer or the entire layer of synthetic resin flooring, the product cost is too high to be used effectively in industry. I don't get it.

Although methods of applying various antistatic agents to the surface are initially effective, the antistatic layer disappears when pedestrians and heavy objects pass by, resulting in poor durability.

The present invention is a novel antistatic flooring material that overcomes the above problems.

(Structure of the present invention) The present invention provides an antistatic flooring material characterized by having a cross-linked polyvinyl chloride surface layer, and a conductive layer and an i-nose bonding base material provided below the surface layer. shall be.

This will be explained below based on the drawings. 1 to 8 are cross-sectional views of the antistatic flooring material of the present invention.

2 is a conductive layer and 3 is a base material.

For example, the surface layer of PvC paste resin 100
Add 0.5 to 5 parts by weight of a plasticizer to each part by weight, color with a pigment if desired, add 0.5 to 5 parts by weight of a crosslinking agent such as dimercaptothiadiazole or dithiol-S-)U azine derivative, and add other strong additives. Add cross-linking aids for basic amines, heat stabilizers, etc., and heat at 150-260°C
Just heat it for 5 minutes. The resulting crosslinked resin layer is desirably crosslinked to a higher degree of crosslinking density by tests such as the swelling method and the curelastometer method than the transparent crosslinked PVC resin that has conventionally been used as the surface layer of flooring materials. is P
It is appropriate to mix the VC paste layer to the extent that it is colored and hides the base layer, and a thickness of 0, B to 1.8 IIJ is desirable.

Examples of the conductive layer 2 include a layer in which 50 to 200% by weight of conductive fibers such as carbon fibers and metal fibers, carbon black, metal powder, etc. are mixed and dispersed in a thermoplastic resin composition such as soft PVC, or a conductive layer. It can be obtained by mixing 20 to 4 or/m' of fibers and 10 to 70 non-conductive fibers such as glass fibers, impregnating them with resin after needling, papermaking, web formation, or other known methods. A sheet will be given to you. At this time, suitable conductive fibers are carbon fibers, copper fibers, stainless steel fibers, and other metal fibers.

In addition to the above, nonwoven fabrics coated with or impregnated with conductive paint and nonwoven fabrics coated with or plated with metal are also suitable.

The conductive layer of the present invention is not limited to the above configuration. Note that the conductive layer preferably has a thickness of 0.1 to 0.5M.

In addition to PVC, the base material 8 is made of ordinary non-crosslinked resins such as PVC, ethylene-vinyl acetate copolymer, non-grade polypropylene, and foamed SBR latex, which are soft synthetic resins used as conventional backing materials for flooring materials, and fibers such as felt. A base material of 0.6 to 1.5 ax is suitable. Further, the boundary 4 between the surface layer and the conductive layer may be bonded by thermocompression, or by PVC.
It may be bonded with paste, acrylic emulsion, or conductive adhesive.

In FIG. 2, the crosslinked PVC surface layer 1, the conductive layer 2, and the base material 8 are the same as those in FIG. 1. An intermediate layer 5 is provided between the crosslinked PVC layer l and the conductive layer 20.

The intermediate layer 5 is formed as a PVC paste layer on the conductive layer z.
It is preferably formed by a method in which the intermediate layer is applied smoothly to a thickness of 0.05 to 0.2 ag, and then heated and cured after the surface layer 1 is placed. At this time, it is desirable that the intermediate layer be as thin as possible. As a result, an antistatic flooring material with a smooth surface can be obtained.

In FIG. 3, the surface layer l and the base material 3 are the same as in FIG. The conductive layer 6 is a sheet made of a synthetic resin such as soft PvC to which a conductive substance such as conductive carbon black, carbon fiber, or metal fiber is added, and preferably has a thickness of 0.1 to 0.8 m. Further, the dimensional stability of the flooring material of the present invention can be further improved by forming the core material layer 7 of woven or nonwoven fabric of synthetic fibers or glass fibers in close contact with the conductive layer.

In the present invention, in order to obtain good antistatic properties, the thickness from the surface of the flooring material to the conductive layer is preferably 0.3 to 1.5 mm.

As a result of the above configuration, the flooring material of the present invention can achieve suppression of electrostatic voltage and early decay of electrostatic voltage, which is desirable as an antistatic flooring material.

(Effect) Although there is no established theory, in the flooring material of the present invention, one charge polarized on the surface layer is immediately diffused into the conductive layer, and the charge density on the other side is relaxed, thereby substantially preventing static electricity damage. It is expected that the level will decrease.

The present invention exhibits excellent antistatic performance and has a relative humidity of 8 at 20'C.
When the voltage is 0.0, the charging voltage is less than 0.4 KV, and the voltage is approximately 0.4 KV.
90% of the charged voltage is removed in 4 seconds.

As a result, as soon as one enters a room where the antistatic flooring material of the present invention has been installed, there is a significant drop in the electrostatic charge voltage. Wristbands, which were considered a necessity for factory workers, will no longer be needed.

Furthermore, by making the conductive layer a nonwoven fabric containing conductive fibers, the conductive layer itself functions as a core material, and good dimensional stability can be obtained.

The present invention has excellent physical properties such as workability, heat resistance as a flooring material, solvent resistance, and no damage even when heavy objects pass through it, and is durable.

Furthermore, since the surface layer can be colored arbitrarily, it is possible to create a bright color tone for the appearance of the flooring material.

Examples are shown below. The unit of formulation is parts by weight.

Example 1 20 tons of carbon fibers pre-impregnated with paste of blend B
04./m'1 glass fibers were mixed at a ratio of Lot/-. A conductive layer made of thick non-woven fabric (sheet resistance 10Ω0
) was obtained.

A layer of non-crosslinking resin (to serve as a base material) with a thickness of about 1 cm is placed on a release paper.
A PVC paste layer of Formulation A is formed, this base layer is pregelled by heating with a far-infrared heater, and the conductive layer is laminated by preheating at this time, and then a crosslinked PVC paste of Formulation C is applied as a surface layer. Coated with 0.6u thickness, 2
Heat cross-linking with 2G'C and solidify the base material, remove the release paper, and apply 2.0. A thick antistatic flooring material of the present invention was obtained.

BC PvC paste resin 60 60
100pvc resin 40
4G plasticizer 70 60 6G Calcium carbonate 100Ba-Zn stabilizer 2Sn stabilizer
1.5 pigment
Trace amount Trace amount dimercaptothiadiazole crosslinking agent 2DBU
(Amine) 1 Example 2 Example! The above conductive layer is partially impregnated onto the PVC paste layer of Formulation A formed in the same manner as above, and the paste layer of Formulation B is coated on the surface, and a smooth intermediate resin layer is formed on the conductive layer by 0.1. A crosslinkable layer of Formulation C is formed thereon and heated and cured in the open to give a total thickness of 2. An antistatic flooring material of O. was obtained.

Example 3 A non-crosslinked PvC sheet with a thickness of ttm as a base material, a glass nonwoven fabric and a thickness of 0.26. A conductive layer (sheet resistance value 15Ω) prepared by adding 50 parts of conductive carbon black to Formulation A and a PVC cross-linked film with an adhesive layer having a thickness of 0.6 μm were laminated under heat and pressure at 140°C to form a 2.0 m thick film. A flooring material of the present invention was obtained.

As a result, the human body charge voltage and physical performance are shown in Table 1, and the charge voltage decay rate is shown in Fig. 4.

Note that Comparative Example 1 is a conventional antistatic flooring material, and Comparative Example 2 is a conventional flooring material for a factory.

The obtained results show that the flooring material of the present invention has superior physical performance and improved antistatic properties compared to conventional antistatic flooring materials.

The flooring material also has clearly better anti-static properties than conventional factory floors.

The attenuation rate was faster than any of the comparative examples, and as a result, as soon as the flooring material of the present invention was installed in a building, the electrostatic voltage was reduced to a level that would not cause electrostatic damage.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views of the antistatic flooring material of the present invention, and FIG. 4 is a charging voltage decay curve. 1 is a surface layer, 2 is a conductive layer, and 3 is a base material. Above: Hi--Q*tiger example 1 ←-→large*9J2 )-→large,! 4PI 3 To → Scolding example 1 Cold-one ■ Soft #12

Claims (1)

[Scope of Claims] 1. An antistatic flooring material comprising a crosslinked polyvinyl chloride surface layer, and a conductive layer and a base material provided below the surface layer. 2. The antistatic flooring material according to claim 1, wherein the conductive layer is a nonwoven fabric containing conductive fibers and glass fibers. 3. The antistatic flooring material according to claim 1, in which a conductive layer made of a synthetic resin with a conductive substance added thereto and a core layer are formed in close contact with each other.