JPS606454A - Antistatic plastic composite sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antistatic plastic composite sheet having a laminated composite structure of plastic conductive sheets containing a conductive oxide such as conductive zinc oxide with a carbon layer interposed therebetween.

In recent years, plastic sheets with decorative patterns have been widely used as flooring and wall covering materials, but as is well known,
Plastic sheets such as polyvinyl chloride resin sheets are easily charged with static electricity generated by friction, so dust and dirt can adhere to them, and when the amount of charge increases, it discharges through the human body to the ground, causing an electric shock. It has problems such as:

For this reason, conventional methods include (a) applying an antistatic agent to the surface of a plastic sheet, (b) incorporating an antistatic agent into the plastic sheet, and (c) adding a carbon blank, which is a conductive material, to the plastic sheet. Methods such as ``containing'' have been generally adopted.

However, in the method (a) described above, the antistatic agent coating layer is J! There is a drawback in terms of durability that the antistatic effect is lost due to the deterioration of the
) method has good durability, but it is difficult to sufficiently reduce the surface resistivity of the plastic sheet because there are significant restrictions on the type and amount of antistatic agent used from the viewpoint of moldability. However, the above method (C) has the drawback that a satisfactory antistatic effect cannot be expected.
Due to the high content of carbon blank, there is no problem when manufacturing black-based PlusDEC (TJ), but when coloring it in other colors, the color becomes dark and dirty. , Disadvantages such as the fact that it is impossible to color in bright, light-colored colors (e.g., pale yellow, yellow, yellow-green, pale green, pale blue, pale pink, pink, pink-red, white, etc.). was there.

Therefore, in order to solve such problems, the applicant has
Patent application 1986-205624 first? f and patent application 1987-
No. 229110 proposed an antistatic plastic sheet (hereinafter referred to as a "conductive sheet" in the present invention) with extremely low surface resistivity, which is made by containing a conductive oxide such as conductive zinc oxide in a thermoplastic resin.

The conductive sheet according to this proposal has a more excellent antistatic effect than conventional plastic sheets that have been subjected to antistatic treatment, and it contains 151 particles of light blue to white conductive oxide. This has the advantage that a colorful pattern can be applied to the coloring of the sheet without affecting the coloring of the sheet.

The present invention is a plastic sheet 1 with a composite structure made using such a conductive sheet, which has antistatic properties,
The object of the present invention is to provide a composite plastic sheet 1- that is excellent in terms of colorability, durability, etc.

As shown in FIGS. 1 and 2, the basic structure of the plastic sheet of the present invention is a composite sheet in which the conductive sheets 1-2.2 described above are integrated by thermocompression bonding on the top and bottom of a carbon fiber layer 1. The carbon fiber layer 1, which forms the intermediate layer, is formed using a carbon nonwoven fabric, a carbon woven fabric, or the like.

The conductive sheet 2.2 contains conductive zinc oxide, conductive titanium oxide, conductive tin oxide, or conductive antimony oxide in a thermoplastic resin such as polyvinyl chloride resin, polyethylene resin, polypropylene resin, or ethylene resin. It is formed by containing 70 to 90% by weight of conductive oxides such as It is thought that it forms an incomplete chain with a defective part of several angstroms or less, and uses this complete or incomplete chain as a conductive path to release frictional static electricity to the outside, thereby exerting a good antistatic effect. .

Next, each conductive oxide contained in the conductive sheet will be explained.

First, conductive zinc oxide is an organoaluminum compound containing an aluminum atom (for example, an aluminum salt of carboxylic acid, an aluminum alkoxide , complex salts of aluminum, etc.) in a ratio of 0.05 to 5 moles is heated and fired at a temperature of about 800 to 1100°C, and then finely pulverized, or by a similar method. The products manufactured are adopted,
The conductive zinc oxide thus obtained generally has a resistance of several Ωcrn.
It forms a white powder with no coloration and a low resistivity of ~ several tens of ohms.

Therefore, by kneading an appropriate amount of a coloring agent therein, it is possible to color the conductive sheet not only in a bright pale color but also in a desired vivid color.

In addition, conductive titanium oxide is a combination of titanium and titanium oxide.
It can be produced by heating and firing at 550 to 1750°C (vacuum) and then pulverizing, or by a similar method.

Furthermore, conductive tin oxide and conductive antimony oxide can be manufactured by igniting naturally occurring ores such as cassiterite and nyanantimony tetroxide in air, or by a similar method. All of these generally form light blue to white powder particles having a low resistivity of several ohms to several tens of ohms.

In this way, the conductive oxide on the upper finger is a pale blue to white powder particle that does not have any adverse effect on the coloring, so by kneading an amount of S colorant, the conductive sheet can be made bright. It is possible to color not only light colors but also bright and colorful desired colors.

In general, with plastic sheets used for flooring and wall coverings, static electricity generated by friction has no place to escape and becomes charged on the surface of the sheet, so dust and dust in the air become charged and adhere to it due to electrostatic induction. The electrostatic charge flows through the human body into the earth, which has a low potential, giving the human body a discharge shock.According to the experimental results of the present inventors, in the case of thermoplastic resin sheets, the surface resistivity If the resistance is about 10 Ω, no harmful effects due to static electricity will be observed, and the content of conductive oxide should be reduced to 4 g of thermoplastic.
: It was confirmed that a surface resistivity within the range described above can be obtained when the resin contains about 70 to 90% by weight of the total amount.

That is, if the content of the oxide in the thermoplastic resin is less than 70% by weight, the surface resistivity of the conductive sheet will be greater than the above range and exhibit a good antistatic effect. On the other hand, it has been confirmed that if the weight ratio exceeds 90%, the strength becomes too weak to be used as a flooring material or wall covering material.

Furthermore, if the content of conductive oxides is less than 70% by weight, the surface resistivity increases and good antistatic effects cannot be obtained. It is inferred that this is because the aforementioned complete or incomplete chain of passages is not sufficiently formed inside the plastic sheet cheek.

However, according to the composite sheet of the present invention, the surface of the sheet where frictional static electricity is likely to be generated is formed of a conductive sheet that has a significantly lower surface resistivity than conventional plastic sheets, and there is an even greater distance between these two sheets. Since a carbon layer, which is a good conductor with a low surface resistivity, is interposed between the sheets, it is thought that the electric charge generated on the surface of the sheet escapes to the ground through the inside of the sheet, and almost no charging phenomenon occurs.

The composite sheet of the present invention is produced by adding any of the conductive oxides produced as described above, or an arbitrary mixture thereof, to the main thermoplastic resin, as a plasticizer, a stabilizer, and a colorant. A conductive material manufactured by preparing a material by mixing and kneading it with various auxiliary materials such as agents, and then molding this material using a desired molding method such as extrusion molding or press molding. A laminated structure is obtained by interposing a carbon non-woven fabric or the like on a sheet and heat-compressing and integrating the sheet using a method such as a pressure roll or multi-stage press processing.

Here, as the thermoplastic resin forming the base material of the conductive sheet, polyvinyl chloride resin, polyethylene resin, polypropylene resin, ethylene vinyl acetate copolymer resin, polymethyl methacrylate resin, polycarbonate resin 1. Cellulose resin Any thermoplastic resin that is easily charged, such as resin, can be used, and various auxiliary materials such as plasticizers, stabilizers, and colorants that are commonly used for conventional thermoplastic resins can be used. Needless to say, both can be used.

As detailed above, the plastic composite sheet according to the present invention is made by laminating conductive sheets, which have a significantly lower surface resistivity than conventional plastic sheets, with a carbon fiber layer having an even lower surface resistivity interposed therebetween. Since it has a composite structure, it has extremely good antistatic properties.
Therefore, it is extremely useful for use as a floor covering material or wall covering material in environments where the generation of dust and static electricity is extremely averse.

In addition, the conductive sheet that forms the surface of the composite sheet contains a conductive oxide in the form of pale blue to white powder that does not have any adverse effect on the coloring of the sheet, so it is possible to color the composite sheet in an appropriate amount. By kneading the agent, the plastic sheet can be colored into a desired bright color, and thus a plastic sheet with a colorful decorative pattern can be obtained.

Finally, examples will be given.

(Example 1) 100 parts of polyvinyl chloride resin (parts by weight, same below), D
60 parts of OP, 3 parts of stabilizer, 400 parts of conductive zinc oxide, and 1 part of pigment (phthalocyanine mixed pigment) were kneaded and extruded to form an antistatic product with a conductive zinc oxide content of about 72% by weight. A polyvinyl chloride sheet (1.5 mm thick) was produced.

Two of the obtained conductive sheets were used to make a carbon nonwoven fabric (
50g/%) was interposed to form an integral body by thermocompression bonding.

The thus obtained three-layer composite sheet had a bright blue-green color with no turbidity on the surface, and its surface resistivity was about 9.6 Xl06Ω, exhibiting good antistatic properties.

(Example 2) An antistatic polyvinyl chloride resin sheet (thickness 1.
Carbon non-woven fabric (20 g/r
rr) to form an integral body by thermocompression bonding.

As in Example 1, the thus obtained composite sheet with a three-layer structure exhibits a bright blue-green color with no turbidity on the surface, and its surface resistivity is approximately 1.1XlO7Ω, indicating good antistatic properties. It showed.

(Example 3) The content of conductive titanium oxide was about 80 parts, which was produced in the same manner as in Example 1, except that the amount of conductive zinc oxide was changed to 800 parts, and 1 part of Bengara pigment was added as a coloring agent. A plurality of antistatic polyvinyl chloride sheets (thickness 1.5 fins) of 1.5% by weight were used, and a carbon nonwoven fabric (20g/rr?) was used between each sheet.
> was interposed to form an integral body by thermocompression bonding.

As in Example 1, the thus obtained composite sheet with a multilayer structure exhibits a bright blue-green color with no turbidity on the surface, and its surface resistivity is approximately i,txio7Ω, exhibiting good antistatic properties. presented.

(Example 4) 100 parts of polyvinyl chloride resin (parts by weight, same hereinafter), D
50 parts of OP, 3 parts of stabilizer, 400 parts of conductive titanium oxide,
The content of conductive titanium oxide produced by kneading 1 part of pigment (phthalocyanine mixed pigment) and extrusion molding is approximately 72%.
% by weight of antistatic polyvinyl chloride resin sheet (thickness 1
．． 5 ml) was produced.

Using two of the obtained sheets, a carbon nonwoven fabric (20
g/n? ) and were integrally bonded by thermocompression. Thus,
As in Example 1, the obtained composite sheet with a three-layer structure has a bright blue-green color with no turbidity on the surface, and its surface resistivity is approximately 1.2 XIO・Ω, indicating good antistatic properties. It showed.

(Example 5) Example 1 except that the amount of conductive titanium oxide was changed to 600 parts.
Similarly, the content of conductive titanium oxide is approximately 80% by weight.
An antistatic polyvinyl chloride resin sheet (thickness: 1.5 mm) was obtained.

Using two of the obtained sheets, a carbon nonwoven fabric (20
g/rrr) to form an integral body by thermocompression bonding.

As in Example 1, the thus obtained three-layered composite sheet 1~ exhibits a bright blue-green color with no turbidity on its surface, and its surface resistivity is approximately 1.4XlO7Ω, showing good charging. It exhibited preventive properties.

(Example 6) The content of conductive titanium oxide was approximately 84 parts by weight, which was produced in the same manner as in Example 1 except that the amount of conductive titanium oxide was changed to 800 parts and 1 part of Bengara pigment was added as a coloring agent. % antistatic polyvinyl chloride resin sheet (thickness 1.5 mm) was produced.

Using two of the obtained sheets, a carbon nonwoven fabric (20
g/rrf), and were integrally bonded by thermocompression. As in Example 1, the thus obtained composite sheet with a three-layer structure exhibits a bright blue-green color with no turbidity on the surface, and its surface resistivity is approximately 1.1XlO7Ω, which indicates good antistatic properties. It showed.

In addition, examples of conductive tin oxide and conductive antimony oxide, as well as mixtures of any of the conductive oxides mentioned above, were added to the thermoplastic resin in an amount of 70 to 90% by weight of the total.
Although the description of the examples manufactured using conductive sheets manufactured by containing the above will be omitted, the same effects as the above-mentioned examples were obtained in all cases.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view showing one embodiment of the plastic composite sheet of the present invention, and FIG. 2 is a schematic longitudinal cross-sectional view showing another embodiment thereof. Patent applicant Takiron Co., Ltd. Representative Ryutabe Yagi, I Kawani; 72nd

Claims (2)

[Claims] (1) A conductive sheet made of a thermoplastic resin containing conductive zinc oxide, conductive titanium oxide, conductive tin oxide, conductive antimony oxide, or any mixture thereof, and a carbon fiber layer. An antistatic plastic composite sheet characterized by being laminated with intervening layers. (2) The conductive sheet contains any one of conductive zinc oxide, conductive titanium oxide, conductive tin oxide, conductive antimony oxide, or any mixture thereof in the thermoplastic resin in an amount of 70 to 90% by weight of the total. The antistatic plastic composite sheet according to claim 1, which contains an antistatic plastic composite sheet.