CH626938A5 - Antistatic floor covering - Google Patents

Description

The present invention relates to a floor covering with an antistatic effect.

For example, it is known to make polyvinyl chloride coverings electrically conductive by mixing in certain special blacks or other conductive parts. The electrical conductivity of these floor coverings is usually between 104-106 Ohm leakage resistance to earth. Such coverings are used in operating theaters of hospitals, where the highest demands are placed on the electrical properties in order to avoid any risk of explosion e.g. switch off when handling ether.

For areas of application in which such a high conductivity is not required, for example in rooms for IT systems, where a leakage resistance of IO6 to IO8 Ohm is sufficient, chemical agents, so-called antistatic agents are added to the flooring, which give the covering the desired conductivity. For the applications where such coverings are used, a higher conductivity from the top to the bottom is not necessary, so that the higher economic outlay for further reducing the leakage resistance is not required. Such floor coverings also relate to the present invention.

There are different areas of application for rubber and plastic floor coverings with different strict requirements for the antistatic properties.

The requirements placed on a good floor covering are in part completely contradictory, so that a middle course is adhered to during production that meets both requirements as well as possible. On the one hand, these requirements consist of the highest possible conductivity in order to avoid electrostatic charges, while on the other hand, the highest possible insulation is required to avoid earth faults.

A network of copper wires is attached to the underside in order to enable the discharge of electrostatic charges that occur with such coverings. Naturally, this requires a special amount of manipulation. In order to obtain a sufficiently high transverse conductivity and to register every part of the covering immediately, the wire mesh must be arranged in a correspondingly close manner, which also has an unfavorable cost effect.

The aim of the invention is to create a floor covering which, although having an extremely high transverse conductivity, has an overall resistance to earth between 106 and 10 8 ohms.

This is achieved according to the invention in that the floor covering has a lower layer made of a mixture with a leakage resistance of 100 to 500 lbs and an upper layer with a leakage resistance of IO6 to 10R Q.

The conductivity of the upper layer can be achieved by containing antistatic chemical agents. Such active ingredients are e.g. Alkyl sulfates, alkyl sulfonates, quaternary nitrogen bases, ethoxylated fatty amines, alkylolamines, phosphoric acid esters, polyglycol esters and the like (see periodical; rubber, asbestos, plastics »No. 2,4,5 and 6,1973; Genter Verlag, Stuttgart; article "Antistatika" by Dr. S. Riethmayer).

The result of the design according to the invention is that electrostatic charges arising in the upper layer can be dissipated through the lower layer which is in contact with the upper layer over the entire surface, a complex manipulation when laying the floor covering not being necessary, but rather the floor covering if necessary, only loosely laid and the lower layer can be grounded on one side.

This can expediently take place in that the lower layer is connected to an earth line via a metallic conductor. This metallic conductor can be attached along only one edge of the floor covering and, if necessary, can be fixed to the underside of the covering by means of a conductive adhesive.

A particularly favorable dissipation of electrostatic charges can be achieved if the thickness ratio of the upper layer to the lower is approximately 10: 1. For this purpose, it is advantageous if the electrical conductivity of the lower layer is achieved by adding soot, so that a high conductivity can be achieved even with a small thickness.

30 Example 1

A particularly advantageous mixture of the upper, antistatic layer consists of the following components:

35E-PVCK70 E-PVC K 65 ketone resin epoxy plasticizer di- (2-ethyl-hexyl) phthalate 40 Zn stearate Cd-Ba stabilizer solid Cd stabilizer liquid chelator chalk 45 stearic acid antistatic e.g. Tebestat JK12 Cyastat LS

50

Example 2

S-PVC K 70 ABS powder

Di- (2-ethyl-hexyl) phthalate 55 Epoxidized soybean oil Cd-Ba stabilizer solid Cd stabilizer liquid chelator chalk 6o stearic acid

Antistatic e.g. Tebestat JK 22

Share 50 50 5

10 29 1.2 1.2 0.7 0.8 50 0.3 5.0

100 11 35 2

1.2 0.7 0.8 50 0.3 10

Example 3

65 The following composition for the lower layer with a leakage resistance of 100 to 500 Q is particularly advantageous for use as a back coating on a floor covering:

3rd

626 938

Parts

E-PVC

100

CD stabilizer liquid

1.0

Cd-Ba stabilizer firmly

2.0

Zn stearate

0.4

Chelator

1.6

Pb stabilizer

0.8

chalk

50

conductive special carbon black pasted with

Di- (2-ethyl-hexyl) phthalate in 50%

146

Concentration e.g. Corax L

The leakage resistance is determined according to ÖNORM 5209 by using a circular measuring electrode made of brass with an area of 20 cm2 without a protective ring with a minimum load of 400 p. On the middle of the surface of the sample, a paper paper with a diameter of 50 mm moistened with tap water is placed and the measuring electrode is placed over the entire surface. The electrical resistance is measured between the graphite electrode on the bottom and the measuring electrode on the top.

The floor covering according to the invention can advantageously be produced by the following method:

In a trough mixer, polyvinyl chloride and powdered stabilizers are intimately mixed for 5 minutes. In the meantime, the necessary dyes and the necessary amount of antistatic in a part of the total plasticizer and the liquid stabilizers are bubbled up with a basket stirrer in a stirred bucket.

After the mixing process has ended, the plasticizer mixed with the dye, stabilizer and antistatic and the residual plasticizer are added to the basic mixture and mixed for 10 minutes. The filler required by the recipe is then added and the mixture is mixed for 10 minutes. A powdery mixture is obtained.

The pattern consists of a basic color, a light and a dark marbling component.

Separated into marbling components, the mixtures are processed on rolling mills at temperatures between 160 ° C. and 190 ° C., preferably 180 ° C., to form homogeneous, approximately 5 mm thick rolled skins.

For marbling, evenly coordinated quantities are taken from the material of the basic and marbling components running on the rolling mills. Rolled up the doll, sent through another rolling mill and then calendered on the calender at temperatures between 170 ° C and 180 ° C to the raw floor covering layer.

15

The mixture produced for the conductive film for the back coating is on a 4-roll calender with suitable kneaders or gelimates and rolling mills at temperatures of 180 ° C to 190 ° C, preferably 20180 ° C to a 0.20 mm thick highly conductive Foil processed.

A continuously operating duplicating system is used to connect the floor covering layer and the conductive back coating, hereinafter referred to as “doubling”. 25 For a covering with a total thickness of 2.2 mm three, 0.70 mm thick floor covering raw layers and a 0.20 mm thick conductive layer are doubled. The conductive layer is applied so that it forms the back of the covering after the doubling process. The layers 30 are doubled at a temperature of 150 ° C. to 180 ° C., preferably at 170 ° C.

The finished covering sheets are slowly heated again to approx. 90 ° C in a tempering channel, left at this temperature for a certain time and then slowly cooled to room temperature. This system works continuously.

C.

Claims (4)

626 938 1. Floor covering with an antistatic effect, characterized in that it has a lower layer made of a mixture with a leakage resistance of 100 to 500 Q and an upper layer with a leakage resistance of IO6 to 108 £ 2. 2. Floor covering according to claim 1, characterized in that the lower layer is connected to an earth line via a metallic conductor. 2nd PATENT CLAIMS 3. Floor covering according to claim 1 or 2, characterized in that the thickness ratio of the upper layer to the lower is about 10: 1. 4. Floor covering according to one of claims 1 to 3, characterized in that the electrical conductivity of the lower layer is achieved by a content of carbon black.