JPH0529550B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a conductive floor sheet that can be freely colored and has sufficient antistatic performance. [Prior Art] A measure to prevent static electricity from forming on rubber or plastic molded products is to lower the electrical resistance of the molded product and quickly ground and dissipate static electricity generated by friction. The following methods are known as methods for lowering the electrical resistance of rubber or plastic. (1) A method of adding highly conductive metal powder or fibers such as silver, copper, stainless steel, or nickel to rubber or plastic. (2) A method of adding carbon black or carbon fiber to rubber or plastic. (3) A method of adding surfactants called antistatic agents or similar substances to rubber or plastic. [Problems to be Solved by the Invention] Although the method (1) above is very effective in preventing static electricity, it cannot be colored freely and is limited to metallic colors. Moreover, it is very expensive and lacks economic efficiency. Furthermore, it is desirable that the electrical resistance of molded products be within a certain range to prevent the risk of electric shock due to low voltage electricity, but it is difficult to stably manufacture such products using metal powder or metal fibers. is extremely difficult. The method (2) above has the drawback that, although carbon black is often used as an inexpensive conductivity imparting agent, the hue is limited to black.
Further, even with this method, it is difficult to industrially and stably produce molded products that are free from the risk of electric shock due to low voltage electricity. Although method (3) above has the advantage of being able to be colored freely, it incorporates a surfactant that has poor compatibility with rubber and plastic and easily absorbs moisture, and bleeds it onto the surface to lower the surface resistance. It dissipates static electricity from the surface, and relies on surface resistance, which is easily influenced by environmental conditions, and lacks stability in antistatic performance. In particular, the antistatic effect will be considerably reduced in a low humidity environment. Moreover, the duration of antistatic performance is short. On the other hand, in recent years, semiconductor parts such as ICs, LSIs, and electrical equipment factories are being used to prevent production failures caused by the adsorption of micron and submicron dust particles due to the generation of static electricity, and in OA rooms, etc. The use of conductive floors is being considered to prevent computer malfunctions and circuit damage. In this case, the above (3) allows you to freely color for aesthetic reasons.
It is preferable to use a sheet obtained by the method of
It is difficult to use alone due to concerns about its ability to prevent static electricity. As a countermeasure to this problem, it is possible to use sheets laminated with the sheet obtained by method (3) above on the front side and the highly conductive sheet obtained by method (1) or (2) above on the back side. It will be done. However, in such a laminated sheet, the static electricity charged on the front side leaks to the conductive layer on the back side and is grounded, but in this case, the volume resistance is more important than the surface resistance, and the sheet using the method (3) above Since the volume resistivity cannot be lowered in this case, a sufficient antistatic effect cannot be obtained. The present invention has been made based on the above,
The object of the present invention is to provide a conductive floor sheet that can be colored in any color and has an excellent antistatic effect. [Means for Solving the Problems] The conductive resin composition of the present invention comprises 100 parts by weight of a polymer component containing 95 to 20 parts by weight of a polyvinyl chloride resin and 5 to 80 parts by weight of an acrylonitrile-butadiene copolymer. A first resin composition comprising 5 to 100 parts by weight of a glycol fatty acid ester having a volume resistivity of 10 ⁸ Ω-cm or less or a plasticizer in which one of the glycols is a fatty acid and the other is an ester of an aromatic carboxylic acid. The first resin composition comprises a sheet and a resin composition in which rubber or plastic contains at least one conductivity imparting agent selected from carbon black, carbon fiber, metal powder, or metal fiber.
This sheet is characterized by being laminated with a second sheet having higher conductivity than the second sheet. In the present invention, the polyvinyl chloride resin may be any resin that normally contains 50% by weight or more of vinyl chloride, such as a homopolymer of vinyl chloride, or a copolymer of vinyl chloride and a monomer copolymerizable therewith. It may be a polymer or a graft copolymer with other resins. Although there are no particular restrictions on the acrylonitrile-butadiene copolymer, one with a high acrylonitrile content is desirable from the viewpoint of compatibility with polyvinyl chloride resin and electrical resistance. It is best to choose accordingly. The content ratio of polyvinyl chloride resin and acrylonitrile-butadiene copolymer in the polymer component is 95 to 20/5 to 80 in weight ratio of polyvinyl chloride resin/acrylonitrile-butadiene copolymer.
It needs to be within the range of If the amount of the acrylonitrile-butadiene copolymer is less than 5 parts by weight, it will not be possible to obtain the desired conductivity, and if it is more than 80 parts by weight, the raw rubber-like properties will become noticeable and the processability will be poor, making it difficult to obtain a product with a smooth surface. It disappears. Additionally, vulcanization is required, increasing the number of manufacturing steps. The plasticizer used in the present invention is not particularly limited in other properties as long as it has a volume resistivity of 10 ⁸ Ω-cm or less, but it is preferably a plasticizer that is liquid at room temperature and has low volatility.
Examples include phosphoric acid esters, glycol fatty acid esters, and esters in which one of the glycols is a resin acid and the other is an aromatic carboxylic acid. By using such plasticizers, it is possible to obtain floor sheets that have excellent antistatic effects and are free from briodes. Specific examples of phosphoric acid esters include cresyl diphenyl phosphate, di(2,3-dibromopropyl) 2,3-dichloropropyl phosphate, di(2-ethylhexyl) phosphate, and dioctyl phosphate. , triamyl phosphate, tri(2-butoxyethyl) phosphate
ester, tri(2-chloroethyl) phosphate, tri(chloropropyl) phosphate,
Phosphate tricresyl ester, phosphate tri(2,
Examples include 3-dibromopropyl) ester and tri(dichloropropyl) phosphate ester. Specific examples of glycol fatty acid esters include:
diethylene glycol-dicaproic acid ester,
Examples include triethylene glycol dicaprylate and triethylene glycol dicaprylate. Specific examples of esters in which one glycol is a fatty acid and the other is an aromatic carboxylic acid include esters of phthalic acid and triethylene glycol-monocaprylic acid ester. In addition, in the present invention, the above-mentioned plasticizer
An electrolyte of about 0.005 to 2% may be added. The electrolyte is preferably a chemically stable electrolyte that does not easily deteriorate, such as lithium chloride or sodium chloride. The amount of plasticizer with a volume resistivity of 10 ⁸ -cm or less for the polymer component containing polyvinyl chloride resin and acrylonitrile-butadiene copolymer is:
The amount of plasticizer should be in the range of 5 to 100 parts by weight per 100 parts by weight of the polymer component. If it is less than 5 parts by weight, it will not be possible to obtain the desired volume resistivity, and if it is about 100 parts by weight, the volume resistivity will be almost saturated, and if it is increased more than this, the electrical resistance will hardly change and the compatibility will worsen. , leading to a decrease in mechanical properties,
This makes it unsuitable for use in the field of thermoplastic resins. In the present invention, in addition to the above ingredients, of course, plasticizers such as DOP, other compounding agents, such as stabilizers, antioxidants, crosslinking agents, vulcanizing agents, vulcanization aids, lubricants, processing aids, etc. , flame retardants, fillers, colorants, ultraviolet absorbers, etc. can be used as appropriate, and the composition can be made without any practical problems. The resin composition thus obtained is formed into a first sheet, which is coated with a conventionally known conductive sheet, that is, rubber or plastic, at least one member selected from carbon black, carbon fiber, metal powder, or metal fiber. By laminating a second sheet having higher conductivity than the first sheet made of a resin composition containing a conductivity imparting agent, a floor sheet with excellent antistatic performance can be realized. [Examples] Example 1 As shown in FIG. 1, a floor sheet having a color conductive layer 1 and a conductive layer 2 was manufactured. Color conductive layer 1 is made of Γ polyvinyl chloride 50 parts by weight Γ acrylonitrile-butadiene copolymer
A compound containing 50 parts by weight Γ tri(2-butoxyethyl) phosphate ester (volume resistivity 8.7×10 ⁶ Ω-cm) and 1 part by weight of Γ phthalocyanine green was mixed using two electrically heated rolls. Molded with high pressure steam press, thickness 0.5mm
It was produced by sheet molding. The conductive layer 2 contains 100 parts by weight of Γ polyvinyl chloride resin, 70 parts by weight of Γ dioctyl phthalate, 80 parts by weight of Γ carbon black, and 5 parts by weight of Γ stabilizer, etc., and has a thickness of 2.5 parts in the same manner as color conductive layer 1.
It was produced by sheet molding to mm. Next, colored conductive layer 1 and conductive layer 2 were laminated using a steam press to produce a floor sheet whose surface was colored green. Example 2 The components of the color conductive layer 1 are: Γ polyvinyl chloride 50 parts by weight Γ acrylonitrile-butadiene copolymer
50 parts by weight Γ Ester of the following *1 (volume resistivity 8.7×10 ⁶ Ω−
cm) 50 parts by weight Γ phthalocyanine green A floor sheet was produced in the same manner as in Example 1 except that 1 part by weight was used. Example 3 The components of the color conductive layer 1 are: Γ polyvinyl chloride 50 parts by weight Γ acrylonitrile-butadiene copolymer
50 parts by weight Γ Ester of the following *2 (volume resistivity 1.3×10 ⁷ Ω−
cm) 50 parts by weight Γ phthalocyanine green A floor sheet was produced in the same manner as in Example 1 except that 1 part by weight was used. Example 4 The components of the color conductive layer 1 are: Γ polyvinyl chloride 50 parts by weight Γ acrylonitrile-butadiene copolymer
50 parts by weight Γ Ester of the following *3 (volume resistivity 4.5×10 ⁶ Ω−
cm) 50 parts by weight Γ phthalocyanine green A floor sheet was produced in the same manner as in Example 1 except that 1 part by weight was used. Comparative Example 1 The components of the color conductive layer 1 were: Γ polyvinyl chloride 50 parts by weight Γ acrylonitrile-butadiene copolymer
50 parts by weight Dioctyl phthalate (volume resistivity 1.3×10 ¹³ Ω−
cm) 50 parts by weight Γ nonionic antistatic agent (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Resistut 141) 2 parts by weight Γ phthalocyanine green A floor sheet was prepared in the same manner as in Example 1, except that 1 part by weight was used. . Comparative Example 2 The components of the color conductive layer 1 were: Γ polyvinyl chloride 100 parts by weight Γ dioctyl phthalate (volume resistivity 1.3×10 ¹³ Ω−
cm) 50 parts by weight Γ nonionic antistatic agent (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Resistut 141) 2 parts by weight Γ stabilizer, etc. 6 parts by weight Γ phthalocyanine green Same as Example 1 except that it was 1 part by weight. A floor sheet was produced using the same method. Table 1 shows the results of measuring the electrical resistance of the laminated sheets produced in Examples and Comparative Examples. The electrical resistance was measured as shown in FIG. That is, a voltage is applied to the copper plate 4 connected to the conductive layer 2 by the DC power supply 5, and 60
Measure the current flowing through the mmφ electrode 3 with an ammeter 7,
Electrical resistance was calculated from Ohm's law. 6 is a voltmeter.

【table】

[Table] As is clear from Table 1, Examples 1 to 4, which fall within the scope of the present invention, have sufficient electrical resistance to prevent electrostatic charging, while Comparative Examples 1 and 2 have high electrical resistance. The lamination effect is not fully demonstrated. [Effects of the Invention] As explained above, it is possible to obtain a conductive floor sheet that can be freely colored and has excellent antistatic performance.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of a floor sheet according to the present invention, and FIG. 2 is an explanatory diagram of a method for measuring the electrical resistance of a floor sheet. 1: Conductive colored sheet, 2: Conductive sheet.

Claims (1)

[Claims] 1 100 parts by weight of a polymer component containing 95 to 20 parts by weight of polyvinyl chloride resin and 5 to 80 parts by weight of acrylonitrile-butadiene copolymer has a volume resistivity.
A first sheet made of a resin composition containing 5 to 100 parts by weight of a plasticizer of a glycol fatty acid ester or a glycol in which one of the glycols is a fatty acid and the ^other is an ester of an aromatic carboxylic acid, and a rubber or a second sheet having higher conductivity than the first sheet, which is made of a resin composition in which plastic contains at least one conductivity imparting agent selected from carbon black, carbon fiber, metal powder, or metal fiber; A conductive floor sheet characterized by being laminated.