JPH0518708B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Fields] The present invention is applicable to electronics-related factories, clean rooms, operating rooms, dying examination rooms, computer rooms, telecommunications rooms, ship radio rooms, explosive factories, combustible materials warehouses, scientific laboratories, etc. The present invention relates to antistatic laminated sheets used on floors in areas susceptible to damage caused by, etc. [Prior Art] Conventionally, floor surfaces in areas susceptible to damage from static electricity or dust have been covered with conductive metal floor materials such as aluminum or stainless steel, or conductive carbon powder, metal powder, or Synthetic resin sheets kneaded with staple fibers were used. However, in the case of the former type of metal sheet, the sheet surface is hard and causes problems such as walking noise and vibration, and since the entire sheet is made of conductive metal, it is highly conductive. There was a risk of electric shock due to electrical leakage in the equipment used above, and there were other problems, such as being expensive and having poor workability. On the other hand, in the case of the latter synthetic resin sheet, due to the abrasion of the sheet surface, the kneaded carbon powder, metal powder, short fibers, etc. peel off from the sheet, and this becomes dust and adheres to, for example, semiconductors and is used in computers. There are problems such as causing failures, metal powders and short fibers deteriorating due to oxidation, antistatic performance decreasing over time, and initial performance disappearing in a short period of time. Ta. [Problems to be Solved by the Invention] The present invention was made against the background of the problems of the prior art. It is an object of the present invention to provide an antistatic layer sheet having a back layer having a conductive function and having excellent durability and dust prevention properties. [Means for solving the problem] That is, the present invention provides an antistatic plasticizer and/or an antistatic agent and/or an antistatic plasticizer and/or an antistatic agent having a volume resistivity of 1×10 ⁶ to 1×10 ¹⁰ Ω·cm on the surface side. Or, it has a dust-proof synthetic resin layer made of a synthetic resin composition mixed with a conductive substance, and has a resistance value of 1× on the back side.
It has a conductive base material layer of 10 ⁰ to 1×10 ⁴ Ω, and has a volume resistivity value of 1×10 ⁶ to 1×10 ¹⁰ Ω・cm as a laminate having a synthetic resin layer and a base material layer. The present invention provides an antistatic laminated sheet characterized by the following characteristics. Hereinafter, the present invention will be explained in detail.The volume resistivity value of the surface side of the antistatic laminated sheet is 1×10 ⁶ ~
The synthetic resin layer with excellent dust prevention properties of 1×10 ¹⁰ Ω・cm is formed from a synthetic resin composition mixed with an antistatic plasticizer and/or an antistatic agent and/or a conductive substance. The thickness of this synthetic resin layer is preferably 0.2 to 5 mm; if it is less than 0.2 mm, the abrasion resistance will be poor, while if it is more than 5 mm, the sheet will tend to warp toward the surface and the distance to the base material layer will be long. As a result, the antistatic function of the resulting sheet deteriorates. Further, this synthetic resin layer may be a single layer or a multi-layer. In the case of a multi-layer, for example, the synthetic resin layer may be composed of an uppermost layer and an intermediate layer of a foam layer disposed below it. A printed layer containing a foaming inhibitor and/or a foaming accelerator may be interposed between the upper layer and the intermediate layer. That is, before heating and expanding the intermediate layer, a foaming suppressor and/or a foaming accelerator that changes the decomposition temperature of the expanding agent blended in the composition of the intermediate layer is applied to the surface of the intermediate layer. Later, by laminating a top layer on these surfaces and then heating it to a temperature at which the expansion agent decomposes, the surface portion of the synthetic resin layer coated with the foaming suppressor and/or foaming accelerator is coated with this layer. It may be formed to have a thickness different from that of the rest of the sheet to give the sheet a three-dimensional design effect. In this case, if the top layer is transparent or translucent, the design effect will be more effectively achieved when the intermediate layer and the printing layer containing the foaming inhibitor and/or foaming accelerator are colored. The thickness of this upper layer is preferably 0.1 to 1 mm. this is,
This is because if the thickness is less than 0.1 mm, the abrasion resistance is poor, while if it exceeds 1 mm, the sheet tends to warp toward the surface and also becomes expensive. Further, the intermediate layer may be a foamed layer as described above or a non-foamed layer, but if the resulting sheet is required to have cushioning properties, the foamed layer is preferably used. Furthermore, this surface layer can be made into a sheet with improved design by partially using colored synthetic resin chips using conductive chips. In addition, examples of the synthetic resin that is the main component of this synthetic resin layer include vinyl chloride resin, acrylic resin, vinyl acetate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, urethane resin, etc. Vinyl chloride resin is preferred in terms of abrasion resistance and cost. The vinyl chloride resin in the present invention refers to polyvinyl chloride resin, vinyl chloride and other monomers,
For example, ethylene, vinyl acetate, vinyl ether,
It also includes copolymers with maleic acid ester, (meth)acrylic acid, (meth)acrylic acid ester, acrylonitrile, urethane, etc., and mixtures of other polyvinyl chloride resins and other polymers. In addition, antistatic plasticizers mixed into the synthetic resin layer include tributoxyethyl phosphate (manufactured by Daihachi Chemical Co., Ltd., TBXP) and butyl diglycol adipate (manufactured by Daihachi Chemical Co., Ltd., BXA). , Sansocizer C-1100 (manufactured by New Japan Chemical Co., Ltd.), SE-673, SE
−172, SE−871 (both manufactured by Riken Vitamin Oil Co., Ltd.)
etc. are preferred, and are used by replacing part or all of general-purpose plasticizers such as dioctyl phthalate, dibutyl phthalate, butylbenzyl phthalate, dioctyl adipate, dihexyl phthalate, diisononyl phthalate, etc. according to the desired volume resistivity value, In addition, the blending amount is usually preferably 5 to 100 parts by weight per 100 parts by weight of the synthetic resin.If it is less than 5 parts by weight, the antistatic property of the sheet obtained will decrease, while if it exceeds 100 parts by weight, the antistatic property will be reduced. not only does not increase proportionally, but also the physical properties of the resulting sheet deteriorate. Furthermore, the antistatic agent mixed into the synthetic resin layer includes commonly used antistatic agents such as cationic, anionic, and nonionic antistatic agents, and the amount thereof is usually 100 parts by weight of the synthetic resin. for,
It is preferably 0.2 to 10 parts by weight; if it is less than 0.2 parts by weight, the antistatic properties of the sheet obtained will decrease, while if it exceeds 10 parts by weight, not only will the antistatic function not increase proportionally, but the physical properties of the sheet obtained will also deteriorate. do. Furthermore, as the conductive substance mixed into the synthetic resin layer, carbon powder, carbon short fibers, inorganic and organic powders or short fibers subjected to surface conductivity treatment [conductive calcium carbonate T130-2500 (Nitto Funka Co., Ltd. ), BC-1, EC-5 (both manufactured by Maruo Calcium Co., Ltd.), Dentol WK-100S (manufactured by Otsuka Chemical Co., Ltd.)
), Thunderon SS-N (manufactured by Nippon Kasuke Dyeing Co., Ltd.)]
It is preferable that the electrical resistance does not decrease due to oxidation. The conductive powder at this time has a particle size of 0.5 to 1000μ.
m, or conductive short fibers, have a particle size of 1 to 600 μm,
The length is preferably in the range of 0.5 to 20 mm. In addition, when using the conductive substance in the top layer of a multi-layer structure, the amount of the conductive substance to be mixed is preferably 50 parts by weight or less, based on 100 parts by weight of the synthetic resin, in order to prevent the generation of dust due to abrasion. It is preferably 5 to 30 parts by weight, and when used in an intermediate layer in a multilayer, preferably 2 parts by weight or more, more preferably 5 to 500 parts by weight, based on 100 parts by weight of the synthetic resin.
Parts by weight. The above compounding agents may be used alone or in combination of two or more. Note that when the synthetic resin layer is a single layer, the antistatic plasticizer or antistatic agent is used without mixing this conductive substance from the viewpoint of dust prevention. Furthermore, when the synthetic resin layer is a multi-layer, the antistatic plasticizer or antistatic agent is used in the uppermost layer without mixing the conductive substance, from the viewpoint of dust prevention. In addition, compounding agents such as plasticizers, stabilizers, fillers, blowing agents, antifungal agents, and colorants may be added as necessary. Next, as the base material layer on the back side of the antistatic laminated sheet, materials that are generally used as sheet base materials, such as natural animal or vegetable fibers, asbestos, glass fiber, rock wool, pulp, etc.
Woven fabrics, non-woven fabrics, knitted fabrics, paper, etc. made of inorganic or organic fibers such as synthetic fibers alone or mixed as appropriate, are impregnated with conductive resin liquid containing conductive substances as described above, and other paper making methods When manufacturing paper such as non-woven fabric or glass-mixed paper, it is necessary to mix conductive fibers, conductive powder, conductive treated powders and fibers, or weave these conductive fibers or conductive treated fibers into paper. You can use woven or knitted fabrics. Among these, nonwoven fabrics and paper (glass mixed paper, inorganic paper, glass fiber paper, etc.) mixed with carbon fiber or carbon powder during paper making are particularly suitable as sheet base materials in terms of dimensional accuracy and cost. . Note that the thickness of this base material layer is usually 0.1 to 2 mm.
is preferable; if the thickness is less than 0.1 mm, the sheet strength of the obtained sheet will be weak, while if it exceeds 2 mm, the cost will increase. In addition, the total sheet thickness of the antistatic laminated sheet consisting of these synthetic resin layers and base material layers is 1 to 7.
mm is preferable. If the thickness is less than 1 mm, unevenness on the floor surface on which the sheet is laid will be easily noticeable, while if it exceeds 7 mm, the sheet will become heavy and difficult to handle during laying, and the cost will increase. It also becomes. When the laminated sheet of the present invention is used as a flooring material, it effectively removes static electricity from people working on it and various equipment, and also eliminates the risk of electric shock due to electrical leakage from equipment. Furthermore, a highly safe flooring material that does not generate dust or dust from the laminated sheet can be obtained. Further, the synthetic resin layer on the surface side can be colored in a wide range of hues when a light-colored antistatic plasticizer, antistatic agent, or the like is mainly used. In addition, when multiple layers are used, a foaming suppressor and/or foaming accelerator may be included in the printing layer interposed between the uppermost layer and the intermediate layer to create a color rich in color and three-dimensional effect. It can form patterns, is highly decorative, and when colored in bright colors, it has the effect of improving indoor lighting efficiency and making the room brighter. Furthermore, when the laminated sheet of the present invention uses a flexible material as the base material, it can be rolled up into a long length together with the synthetic resin layer of the surface layer, and is highly flexible and does not break even when folded. It also has excellent workability. When constructing the laminated sheet of the present invention, metal foil is partially adhered to the joint between the sheets on the back side of the sheet, and further metal foil with a ground wire connected to the edge of the sheet is adhered to provide grounding. It can also be installed using regular construction adhesives, or if the construction base is conductive such as concrete,
It is possible to perform construction using a conductive adhesive or a combination of both. Furthermore, when laying the antistatic laminated sheet of the present invention, for example, in addition to using it in the form of a long sheet, it can be used in the form of tiles cut to a predetermined width using a general construction adhesive (synthetic rubber latex type). , vinyl acetate resin solvent-based, epoxy resin-based, acrylic emulsion-based, EVA emulsion-based, etc.) or a conductive adhesive to the floor surface of the raised floor. It can also be used as [Function] The antistatic laminated sheet of the present invention has a dust-proof synthetic resin layer having a volume resistivity of 1×10 ⁶ to 1×10 ¹⁰ Ω·cm on the front side, and a resistance value on the back side. 1×10 ⁰
A conductive base material layer of ~1×10 ⁴ Ω was arranged, and the volume resistivity value of the laminate having a synthetic resin layer and a base material layer was set to 1×10 ⁶ – 1×10 ¹⁰ Ω・cm. To improve the antistatic function, which effectively removes static electricity generated by the sheet itself and other parts by dissipating it horizontally and vertically, thereby preventing the generation of static electricity and the adhesion of dust to the sheet surface. I can do it. Furthermore, a multi-layered synthetic resin layer with so-called chemical embossing is highly decorative. [Examples] Examples of the present invention will be described in detail below. Example 1 The antistatic laminate sheet of Example 1 is made of conductive glass containing glass fiber, pulp, synthetic resin binder, etc., which is made by mixing 5% by weight of carbon fiber into a conductive base material (base material layer). Mixed paper (resistance value: 2.1×
10 ² Ω, thickness: 0.45 mm), the foamable vinyl chloride resin paste () listed in Table 1 was applied to the surface of this conductive glass mixed paper to a thickness of 0.6 mm, and heated at 180°C. After heating for 1 minute to gel, a part of the pattern is printed with multicolor gravure printing using printing ink containing a foaming inhibitor, and then the surface of the sheet with this printing is further printed. After applying the transparent vinyl chloride resin paste () listed in Table 1 to a thickness of 0.4 mm, the foamable vinyl chloride resin paste () was foamed by heating at 210°C for 1 minute and 40 seconds. The total thickness has good decorative properties by matching the printed pattern and the uneven pattern.
It is a 2.0mm sheet. This antistatic laminate sheet has a volume resistivity of 9.0×10 ⁸ Ω・cm, a resistance value of 5×10 ^{6 Ω based on the static electricity safety guidelines of the Industrial Safety Research Institute of the Ministry of Labor, and a charge decay time of 9.0×10 8} Ω・cm. (STATIC Decay
Meter 406B: 5kv+, - applied, 0% cut off:
FD/Method 406C) was 0.03 seconds, which was excellent.

【table】

[Table] The volume resistivity values are those manufactured by Toa Denpa Kogyo Co., Ltd.
Measured with an SM-10E super insulation meter. Moreover, the resistance value of the conductive base material is a value measured with a normal resistance meter. Furthermore, the resistance value of the synthetic resin layer is a value measured when each synthetic resin composition is processed into a sheet shape. Example 2 The antistatic laminated sheet of Example 2 is the same as that of Example 1.
Using the same conductive base material and transparent vinyl chloride resin paste () as the antistatic laminate sheet, we have newly added the foamable vinyl chloride resin paste listed in Table 2 in place of the foamable vinyl chloride resin paste (). ( ) was used in the same manner as in Example 1 to produce a laminated sheet with a total thickness of 2.0 mm and a good decorative quality in which the printing pattern and the uneven pattern matched. This antistatic laminated sheet has a volume resistivity of 3.6 x 10 ⁸ Ωcm, a resistance value of 2 x 10 ⁶ Ω based on the static electricity safety guidelines of the Industrial Safety Research Institute of the Ministry of Labor, and a charge decay time of 0.02 seconds. It showed antistatic properties.

[Table] Example 3 The antistatic laminated sheet of Example 3 is the same as that of Example 1.
In addition to the same conductive base material as the antistatic laminated sheet of Example 2, transparent vinyl chloride resin paste () and foamable vinyl chloride resin paste () listed in Table 3 were newly used. ,
Using the same method as in Example 1 and Example 2, a total thickness of 2.0 mm with good decorativeness and a matching printed pattern and uneven pattern was obtained.
It is a laminated sheet. This antistatic laminated sheet has a volume resistivity of 6.5×10 ⁹ Ω・cm, a resistance value of 3×10 ⁷ Ω based on the static electricity safety guidelines of the Industrial Safety Research Institute of the Ministry of Labor, and a charge decay time of 0.04 seconds. It had antistatic properties.

【table】

[Table] Example 4 The antistatic laminated sheet of Example 4 is the same as that of Example 1.
The colored vinyl chloride resin paste () listed in Table 4 is applied to the surface of the same conductive base material as the antistatic laminated sheet to a thickness of 1 mm, and this is heated at 200°C for 2 minutes to gel and create a pale color. It is a laminated sheet with a total thickness of 1.5 mm that is colored in a plain color. This antistatic laminate sheet has a volume resistivity of 4.0×10 ⁷ Ω・cm, a resistance value of 2×10 ⁵ Ω based on the static electricity safety guidelines of the Industrial Safety Research Institute of the Ministry of Labor, and a charge decay time of 0.02 seconds. It had antistatic properties.

【table】

[Table] Comparative Examples 1 to 3 The vinyl chloride resin paste compositions in Table 5 were
Using the combinations listed in the table and using the same method as in Example 1, a laminated sheet having a total thickness of 2.0 mm and having a matching printed pattern and a concavo-convex pattern and good decorative properties was obtained. Table 6 shows the results of measuring the volume resistivity value, resistance value based on the static electricity safety guidelines of the Industrial Safety Research Institute of the Ministry of Labor, and charge decay time of this laminated sheet. As is clear from these results, all of them have poor antistatic performance and are unsuitable for use in the field targeted by the present invention.

【table】

【table】

〔Effect of the invention〕

As described above, the antistatic laminate sheet of the present invention has a volume resistivity value of 1×10 ⁶ to 1× on the surface side.
A dustproof synthetic resin layer of 10 ¹⁰ Ωcm is arranged, and a conductive base material layer with a resistance value of 1 × 10 ⁰ to 1 × 10 ⁶ Ω is arranged on the back side, and the synthetic resin layer and the base material The volume resistivity value as a laminate having layers is 1×10 ⁶ to 1×
By setting the resistance to 10 ¹⁰ Ω・cm, the static electricity generated on the sheet itself and other parts is released horizontally and vertically, effectively eliminating static electricity, thus preventing the generation of static electricity and the adhesion of dust to the sheet surface. In the production of this sheet, it is possible to improve the antistatic function, prevent dust generation, and eliminate the need for special means to electrically connect the synthetic resin layer and the base material layer. , the number of manufacturing steps can be reduced, and therefore costs can be reduced. In addition, a multi-layered synthetic resin layer subjected to so-called chemical embossing has excellent decorative properties in addition to antistatic properties, and is useful for applications such as flooring.

Claims (1)

[Claims] 1 Volume resistivity value 1×10 ⁶ to 1× on the surface side
1 ¹⁰ Ω・cm, has a dust-proof synthetic resin layer made of a synthetic resin composition mixed with an antistatic plasticizer and/or an antistatic agent and/or a conductive substance, while having a resistance value on the back side. 1×10 ⁰ to 1×10 ⁴ Ω
An antistatic device characterized by having a conductive base material layer, and having a volume resistivity value of 1×10 ⁶ to 1×10 ¹⁰ Ω・cm as a laminated unit having a synthetic resin layer and a base material layer. Laminated sheet for use.