JP4825007B2 - Conductive floor and its construction method - Google Patents

Description

  The present invention includes industrial factories such as semiconductors, liquid crystal devices, foods, pharmaceuticals, and biotechnology, hospitals, elementary schools, junior high schools, high schools, universities, etc., houses such as individual houses and apartment houses, and mills, etc. The present invention relates to a flooring of a factory that handles powder and a method of its construction.

  The flooring is used, for example, on a concrete floor like a long flooring, but it must be cushioned and slippery so that it can be safely walked, and the surface is abradable. Is required to be small and to have a beautiful appearance.

  The flooring material is also required to be antistatic. When the floor material is made of a resin material, the floor surface is charged by friction caused by walking and adsorbs dust and the like, thereby contaminating the floor surface. Also, in factories that handle precision parts such as semiconductor and liquid crystal device factories, when workers walk, static electricity is charged on clothes and the human body, adsorbing dust and the like, which also affects product quality. Furthermore, when the human body or clothes are charged with static electricity, for example, when touching a door knob or the like, static electricity is discharged between the fingertip and the door knob, which is uncomfortable. For this reason, it is necessary to devise so that the floor material becomes conductive so that the floor and the human body are not charged with static electricity.

  Conventionally, in order to solve such a problem, for example, a method of kneading an organic or inorganic antistatic agent or a conductive material into a floor material in a polyethylene-based resin has been employed (see, for example, Patent Document 2). . However, it is difficult to obtain sufficient antistatic performance with an organic antistatic agent, and there is a problem that the antistatic agent diffuses into the air due to friction, volatilization, etc., and contaminates the air. In view of the fact that the antistatic agent is reduced by diffusing into the air, there is also an uneconomical problem that a large amount of the antistatic agent must be added in advance.

As the conductive material, for example, carbon particles or zinc oxide is used on the floor material surface. However, as in the case of antistatic agents, even when using conductive materials, release / diffusion into the air becomes a problem, and in fact, the yield of semiconductor products in semiconductor factories using floor materials with carbon layers and zinc oxide layers. There have been reports of problems with quality degradation.
Japanese Examined Patent Publication No. 2-51387 JP 2001-192984 A JP 2001-261906 A

  The present invention has practicality such as walking performance, cushioning performance, durability, wear resistance, slip resistance and the like, and there is no problem of scattering (outgas) of additives such as antistatic agents, and static electricity on the floor surface. An object of the present invention is to provide a conductive floor that can reliably discharge the floor to the floor and a simple construction method thereof.

  As a result of intensive studies, the present inventors have used the special copolymer having conductivity itself as a flooring material, and filled the gap between the flooring materials with a conductive joint material to solve the problem. The inventors have found that the problem can be solved and have completed the present invention.

That is, the present invention includes the following inventions.
(1) A plurality of flooring materials having a surface material film layer having a surface resistance value of 10 ⁹ Ω or less, which is bonded to an electrically grounded floor floor made of concrete with an epoxy or urethane adhesive, The surface material film layer is composed of a joint material having a resistance value of 10 ⁹ Ω or less and filled in a gap between the floor materials so as to be in contact with both the surface material film layer and the floor base. A conductive floor in which static electricity is discharged to the floor base through the joint material.
(2) The joint material is a copolymer of an unsaturated monomer containing a carboxyl group and an α-olefin monomer, and the carboxyl group is partially a salt with a monovalent and / or divalent metal. The conductive floor according to (1) above, which is a resin containing a copolymer.
(3) At least one monovalent and / or 2 selected from the group consisting of potassium, sodium, lithium, calcium, magnesium and zinc, 30 to 90% of the carboxyl groups in the copolymer of the joint material The conductive floor according to (2) above, which is a salt with a valent metal.
(4) The conductive floor according to (1), wherein the joint material is a nonconductive polymer to which a conductive filler is added.

(5) Adhering a plurality of floor materials having a surface material film layer having a surface resistance value of 10 ⁹ Ω or less to a floor base made of electrically grounded concrete using an epoxy or urethane adhesive, Next, a joint material having a resistance value of 10 ⁹ Ω or less is filled in a gap between the floor materials so as to be in contact with both the surface material film layer and the floor base, and the static electricity charged in the surface material film layer is charged. A method for constructing a conductive floor that discharges to the floor base through the joint material.

  According to the present invention, factories in industrial fields such as semiconductors, liquid crystal devices, foods, pharmaceuticals, and biotechnology, hospitals, elementary schools, junior high schools, high schools, universities, etc., houses such as individual houses and apartment houses, and flour mills A conductive floor can be formed by a simple method on the floor of a factory that handles powder such as.

  In addition, since the conductive floor of the present invention does not require the addition of an additive such as an antistatic agent, for example, when it is used on a floor in a factory or the like, the manufactured product may be contaminated with an antistatic agent or the like. There is an advantage that the product yield can be improved without being contaminated. In addition, by using the conductive floor of the present invention on the floor of hospitals and schools, there is no outgas that has been a problem in hospitals and schools so far, so patients, students, students, etc. are protected from these contaminants. Can do. Furthermore, when the conductive floor of the present invention is used in a factory handling powder, the powder and dust that have been stuck to the resin floor material due to static electricity can no longer be stuck, so it can be easily removed by cleaning. In order to do so, the sanitary environment of the factory can be kept clean.

In the present invention, a plurality of flooring materials having a surface material film layer having a surface resistance of 10 ⁹ Ω or less are arranged on the floor and bonded to the floor base, and then a joint material having a resistance value of 10 ⁹ Ω or less is used as the joint. The conductive floor construction method includes filling a gap between the floor materials so that the material contacts both the surface material film layer and the floor ground which is electrically grounded.

  In the present specification, that the carboxyl group is “neutralized” means that the carboxyl group forms a salt with a monovalent and / or divalent metal. “Unneutralized” means that the carboxyl group is in a free carboxylic acid state. “Neutralization rate” refers to the proportion (%) of the carboxyl groups forming the metal salt in the total carboxyl groups in the copolymer, and “unneutralization rate” refers to the copolymer. It means the ratio (%) of the carboxyl group in the free acid state among all the carboxyl groups in the inside.

Hereinafter, the present invention will be described with reference to FIG. 1, but the present invention is not limited thereto.
The structure of the flooring ("flooring A" and "flooring B" in Fig. 1)
i) Film layer for surface material ("1" and "1 '" in FIG. 1)
The surface material film layer used in the method of the present invention constitutes a surface on which a human walks (grounds). In order to make the floor antistatic, it is preferable to use a resin film having a surface resistance of 10 ⁹ Ω or less for the surface material film layer. Such an antistatic surface material film layer is a copolymer of a carboxyl group-containing unsaturated monomer and an α-olefin monomer, wherein the carboxyl group in the copolymer is partially monovalent and A resin film layer containing a copolymer (hereinafter also referred to as “copolymer (A)”) that is a salt with a divalent metal is preferred. The ratio of the unsaturated monomer component containing a carboxyl group in the copolymer (A) is usually 5 to 25 mol%, preferably 10 to 20 mol%, relative to the α-olefin monomer component.

  The molecular weight of these copolymers is generally expressed in terms of melt flow rate (MFR: unit g / 10 min) rather than measuring it. MFR is measured according to the method specified in JIS K 7120 by applying a load of 2.16 kg or 10 kg and measuring the amount of resin (g) flowing out in 10 minutes at a temperature of 190 ° C or 230 ° C. The smaller the molecular weight of the resin, the easier it is to flow in the molten state and the MFR increases. On the other hand, the larger the molecular weight, the more difficult it is to flow, so the MFR becomes smaller. The MFR of the copolymer resin used in the present invention is preferably 0.1 to 20 (g / 10 min) at 190 ° C. using a weight of 2.16 kg, more preferably 1 to 15 (g / 10 min).

  The unsaturated monomer containing a carboxyl group is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid and maleic anhydride.

  Although it does not specifically limit as an alpha olefin monomer, For example, although C2-C8 alpha olefins, such as ethylene, propylene, and butene, are mentioned, ethylene is preferable.

The copolymer (A) used in the present invention is characterized in that a carboxyl group present in the copolymer (A) partially forms a salt with a monovalent and / or divalent metal. . When the carboxyl group in the copolymer is partially converted to a metal salt, the surface resistance value of the resin film layer for a surface material is lowered, and the chargeability of the flooring can be improved. The proportion of all the carboxyl groups in the copolymer (A) that form a metal salt is not particularly limited. For example, the surface resistance of the resin film layer is more preferably 10 ⁹ Ω or less. The ratio is preferably 10 ⁸ Ω or less, more preferably 10 ⁷ Ω or less. Using monovalent and / or divalent metals (for example, using an alkali metal and an alkaline earth metal in combination), among all the carboxyl groups in the copolymer (A), for example, 30 to 90%, Preferably, the surface resistance of the film layer for the surface material is about 10 ⁶ to 10 ⁹ Ω by making about 50 to 80% metal salt (that is, neutralization rate is 30 to 90%, preferably about 50 to 80%) It can be. If the proportion of the metal salt in the total carboxyl group in the copolymer is too low, the surface resistance of the resin film layer tends to be high, and if the proportion is too high, the strength of the resin film layer decreases, which is not preferable. .

The metal salt of the carboxyl group is not particularly limited as long as it is a monovalent and / or divalent metal salt. For example, alkali metal (lithium, sodium, potassium, etc.), alkaline earth metal (magnesium, calcium) , Strontium, etc.), and zinc salts, and the like. Salts with potassium and calcium and / or zinc are preferred. In this invention, it is preferable to neutralize 50-70% of the carboxyl groups in a copolymer (A) using potassium as a metal (it is set as a potassium salt). When potassium is used, the electrical resistance of the film can be reduced to 10 ⁷ Ω or less, and in addition to the use of other metals in terms of surface adhesion, resistance to dirt, and wear resistance. It can be a flooring material with excellent performance. In addition, the metal salt of the carboxyl group in the copolymer (A) is not limited to one type, and a plurality of metal salts may be mixed.

  Since the surface material film layer used in the present invention itself has conductivity (antistatic property), the amount of organic or inorganic antistatic agent or conductive material added to the resin film layer is conventionally Compared with other flooring, it can be greatly reduced. Since organic or inorganic antistatic agents and conductive substances also cause dust and outgas, they are preferably not added to the surface material film layer. Further, since the pigment is a causative substance of dust and outgas and may contaminate the air, it is preferable not to add an additive or a pigment.

  The thickness of the film layer for a surface material used in the present invention is preferably 30 to 200 μm, more preferably 60 to 100 μm in consideration of durability, aesthetics, strength, and the like.

  The surface resistance can be measured using, for example, pAmeter manufactured by Agilent Technologies.

ii) Intermediate layer and / or film layer for back material ("2" and "2 '" in FIG. 1)
Flooring used in the present invention the intermediate layer on the surface material for the film layer, Ru der formed by laminating a plurality of layers, such as backing material for the film layer.

  The floor material used in the present invention is further provided with an intermediate layer on the resin film layer for the surface material for the purpose of giving the floor material strength, cushioning properties, etc., or for enhancing the adhesion of the floor material to the floor base. Or a film layer for the back material may be laminated.

As an intermediate | middle layer intermediate | middle layer, the resin composition which can be thermally bonded with the film layer for surface materials is mentioned, for example. Examples of such a resin composition include copolymers of acrylic acid ester and / or methacrylic acid ester and α-olefin, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyvinyl alcohol-polyolefin copolymer, ethylene -Olefin-type elastomers, such as vinyl alcohol copolymer (EVA) and ethylene-polyolefin copolymer, etc. are mentioned. One of these may be used alone, or two or more may be used in combination. As the ethylene-vinyl acetate copolymer, a copolymer obtained by copolymerization of ethylene and vinyl acetate, and having about 1 to 10% by mole of vinyl acetate with respect to ethylene can be used. Further, the ethylene-vinyl alcohol copolymer is produced by saponifying the above-mentioned ethylene-vinyl acetate copolymer, and it is preferable that 90% or more of the vinyl acetate ester moiety is a hydroxyl group. The polyvinyl alcohol is preferably one in which 90% or more of the ester portion of polyvinyl acetate obtained by polymerizing vinyl acetate is saponified to become a hydroxyl group. Further, a high-pressure polyethylene obtained by polymerizing ethylene and other α-olefins with a radical initiator under high pressure and high temperature, or an ethylene / α-olefin copolymer may be mixed and used.

  The MFR of the resin used for the intermediate layer is preferably about 0.5 to 200 at a load of 10 kg at 230 ° C., more preferably 1 to 100.

Film layer for back material The film layer for back material is adhered to the floor base such as concrete floor using an adhesive, but when a polyolefin resin is used as the film layer for the back material, the adhesion between the two is not sufficient. There may not be. For this reason, as a method for adhering the polyolefin-based back material to the floor, for example, a method for processing the adhesion surface to facilitate adhesion is proposed. However, processing a large area flooring requires new equipment and extra processing time.

  The present inventors have solved the problem of the adhesive strength between such a back material and a floor base, which is a copolymer of an unsaturated monomer containing an carboxyl group and an α-olefin monomer, wherein the carboxyl group is substantially It has been found that the problem can be solved by using an unneutralized copolymer as the back material.

  The film layer for the back material is preferably a resin film layer that can be bonded to the floor base with an adhesive such as an epoxy or urethane adhesive. As such a film layer for a back material, a copolymer of an unsaturated monomer containing a carboxyl group and an α-olefin monomer, wherein the carboxyl group is substantially unneutralized (hereinafter, A resin film layer containing "copolymer (B)") is preferred. The ratio of the unsaturated monomer component containing a carboxyl group in the copolymer (B) is usually 5 to 25 mol%, preferably 10 to 20 mol%, based on the α-olefin monomer component.

  The unsaturated monomer containing a carboxyl group is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid and maleic anhydride.

  Although it does not specifically limit as an alpha olefin monomer, For example, although C2-C8 alpha olefins, such as ethylene, propylene, and butene, are mentioned, ethylene is preferable.

  In the present invention, “carboxyl group is not neutralized” means 50% (mol) or more, preferably 60 to 99% (mol), more preferably 70 to 99% of all carboxyl groups in the copolymer (B). It means that 99% (mol) is present in an unneutralized carboxyl group (that is, a carboxyl group in a free acid state) (that is, an unneutralized rate of 50% or more, preferably 60 to 99%, More preferably 70 to 99%). By using the copolymer (B) as described above as the film layer for the back material, the adhesiveness with an adhesive (particularly an epoxy or urethane adhesive) is improved.

  In the floor material of the present invention, static electricity is discharged from the surface material film layer to the floor ground which is electrically grounded (grounded) through the joint material, so that the intermediate layer and the back material film layer are antistatic. There is no need. Therefore, it is not necessary to add an organic or inorganic antistatic agent to the intermediate layer in the film layer for the back material. However, if desired, a known organic or inorganic antistatic agent may be added to the film layer for the back material.

  In the present invention, as the monomers of the copolymers (A) and (B), in addition to the unsaturated monomer containing the carboxyl group and the α-olefin monomer, an acrylate ester and / or a methacrylic ester monomer, if desired. A copolymer obtained by polymerization in combination may be used. Examples of these esters include (meth) acrylic acid methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, and hydroxyethyl ester. The use ratio of the (meth) acrylic acid ester is preferably 5 to 10 parts by weight with respect to 100 parts by weight in total of the unsaturated monomer containing the carboxyl group and the α-olefin monomer.

  Furthermore, the film layer for surface materials and the film layer for back materials used in the present invention can be used by mixing known low density polyethylene. The amount of the low density polyethylene used in that case can be added in the range of 0.1 to 20 parts by weight with respect to 100 parts by weight of the copolymer (A) or the copolymer (B).

  There are various methods for electrically grounding the ground floor. If the floor of the second floor or higher is concrete, the concrete itself is conductive enough to dissipate static electricity. Therefore, the reinforcing bars placed in the concrete, concrete slabs, anchor bolts or suspensions on the deck It is possible to ground by connecting a copper wire to a metal fitting, and a steel material that structurally supports them, and then connecting the copper wire to a thick copper rod embedded in the ground. If the ground floor of the first floor is concrete, you may use the same grounding method as above, or if the concrete of the ground floor of the first floor is in direct contact with the ground, Even without grounding, you can escape static electricity to the ground through concrete.

Method for producing a flooring material used in manufacturing the present invention will now flooring will be described.
The copolymer (A) and copolymer (B) used in the present invention can be produced by the following known methods. For example, first, an unsaturated monomer containing a carboxyl group as a raw material, an α-olefin, and, if necessary, other monomers (for example, (meth) acrylic acid esters) are pressurized in a compression step and supplied to the autoclave. The mixture is heated from the surroundings, a radical polymerization initiator such as an organic peroxide is supplied, and a polymerization reaction is performed to obtain a copolymer.

  Next, if the copolymer obtained as described above is formed into a sheet as it is, the copolymer (B) used as the film layer for the back material can be obtained.

  Moreover, it can be set as the copolymer (A) used with the film layer for surface materials by converting a part of carboxyl group in a copolymer into a metal salt as follows. First, the copolymer is pulverized and pulverized. Next, the finely divided copolymer is dispersed in water, and a predetermined amount of a monovalent and / or divalent metal hydroxide such as potassium, sodium, magnesium, calcium, or zinc is added thereto and stirred at high speed. By converting a carboxyl group into a metal salt by this, a copolymer (A) can be obtained.

  The copolymers (A) and (B) thus obtained are dried by, for example, spray drying and then granulated by an ordinary extruder or the like. The granulated products of the copolymers (A) and (B) are formed into a film by an extrusion molding machine or a film molding machine by mixing other polymers (for example, low density polyethylene) as necessary. Thus, a film layer for a front material and a film layer for a back material containing the copolymers (A) and (B) are obtained.

  Although the thickness of the film layer for surface materials changes with purposes, it is 30-30 micrometers normally. In the case of such a thickness, since it is almost transparent, the colors of the intermediate layer and the film layer for the back material are not shielded. For this reason, if a pigment is added to the intermediate layer or the backside film layer only, it can be colored to create a brightly colored flooring, and the intermediate layer or the backside film layer is coated with the surface material film layer. Therefore, the scattering of the pigment due to walking wear or the like does not occur.

  In order to color the flooring material of the present invention, a colorant is added to the next layer (that is, the intermediate layer or the backside film layer) to be bonded to the surface material film layer and colored. Organic and inorganic pigments are added to the colorant, and the type and amount used depend on the required color.

  As described above, since the intermediate layer and the back material film layer are covered with the front material film layer, additives (for example, an antioxidant, a heat stabilizer, a light stabilizer) are added to the intermediate layer and the back material film layer. , Ultraviolet absorbers, lubricants, antibacterial agents, flame retardants, etc.) are not mixed, and there is no risk of outgas and dust scattering.

  Furthermore, you may add a filler to the intermediate | middle layer and the film layer for back materials. Examples of the filler include calcium carbonate, aluminum hydroxide, alumina, and magnesium hydroxide. The use ratio of these fillers can be about 0.1 to 40% by weight with respect to the intermediate layer or the film layer for the back material.

  Further, the intermediate layer can be foamed and used as a foam. As the foaming agent, a type that generates nitrogen when heated, such as a diazo compound, is easy to use. Further, it can be foamed with a well-known low-boiling solvent or a chlorofluorocarbon compound with less ozone destruction. The expansion ratio is preferably 1.5 to 10 times the original volume, usually about 2 to 5 times. A foamed product using the above filler can also be used.

  The above surface material film layer is extruded into a sheet shape by an extruder or the like, and is used for the floor material used in the present invention. In order to laminate the surface material film layer and the intermediate layer and / or the back material film layer into a flooring material, the surface material film layer and the back material film layer are coextruded at the same time, and simultaneously laminated by thermocompression bonding. That's fine. Alternatively, the surface material film layer and the intermediate layer and / or the back material film layer are produced separately, and these are continuously supplied in a sheet form to a hot roll, and are used in the present invention after being pressurized and heated. Can be obtained. Although the thickness of this sheet | seat changes with the number of sheets bonded together in the whole flooring, it is 0.3-3.0 mm normally.

  A flooring material obtained by laminating a film layer for a surface material and an intermediate layer and / or a film layer for a back surface material, if desired, has appropriate flexibility, but a cloth-like backup material is provided on the back surface material film layer for reinforcement. May be affixed. Examples of such a back-up material include a fabric fiber or a non-woven fabric formed using a plant fiber material such as cotton, hemp, cocoon and canresha and a synthetic fiber material such as polypropylene fiber, polyester fiber, poval fiber and acrylic fiber.

  These backup materials and a surface layer laminated with an intermediate layer and / or a back layer are supplied to a pressure roll and bonded together. Or the film layer for surface materials, the film layer for back materials, and an intermediate | middle layer are bonded together first, and this is finally supplied to a thermocompression-bonding roll machine with a cloth-like backup material, and the method of bonding is mentioned.

As a method for producing a flooring material having a film layer for a surface material and a film layer for a back material, a method in which the members are separately produced and bonded together as described above is general, For example, a copolymer of an unsaturated monomer containing a carboxyl group and an α-olefin monomer, wherein the carboxyl group is a salt of a monovalent and / or divalent metal and has a surface resistance of 10 ^9. The method of manufacturing the film (film layer for surface materials) of the copolymer (A) which is below (omega | ohm) and making one side of this film layer for surface materials contact with an acid is also mentioned. By bringing one surface of the surface material film layer into contact with an acid, the carboxyl group is substantially unneutralized on one surface side of the surface material film layer (for example, 60 to 99% of all carboxyl groups are free carboxyl groups). The surface can be Examples of the method of contacting with an acid include a method of washing one surface of a film layer for a surface material with an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, phosphoric acid or an organic acid such as acetic acid, or a method of applying an acidic aqueous solution thereof. Is mentioned.

  According to this manufacturing method, there is no need for a step of bonding the front surface material and the back surface material using the resin composition intermediate layer or the like, and the floor material of the present invention can be manufactured by a simple acid treatment step. In addition, since the floor material manufactured by this method includes a surface material and a back material made of a single copolymer film, there is no possibility that the surface material and the back material are delaminated.

  Alternatively, both the surface material film layer and the back material film layer are copolymers of an unsaturated monomer containing a carboxyl group and an α-olefin monomer, and the carboxyl group is partially monovalent and / or Using a copolymer that is a salt with a divalent metal, if necessary, pressing and molding an intermediate layer between them, and contacting only one side of the molded sheet with an acidic aqueous solution Also good.

Joint material ("3" and "3 '" in Fig. 1)
The joint material used in the present invention is not particularly limited as long as its resistance value is 10 ⁹ Ω or less. The joint material is, for example, a copolymer of an unsaturated monomer containing a carboxyl group and an α-olefin monomer, wherein the carboxyl group is partially a salt with a monovalent and / or divalent metal. Examples thereof include resins containing a polymer as a main component.

Further, 30 to 90% of the carboxyl groups in the copolymer are, for example, at least one monovalent and / or divalent selected from the group consisting of potassium, sodium, lithium, calcium, magnesium and zinc. A salt with a metal is preferred. An acrylic acid ester and / or a methacrylic acid ester (for example, methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, hydroxyethyl ester, etc.) may be further added to the copolymer. Furthermore, a resin containing as a main component a polymer selected from ethylene-vinyl acetate copolymer, polyvinyl alcohol, and polyvinyl alcohol-polyolefin copolymer may be used as the joint material. Further, high-pressure polyethylene obtained by polymerizing ethylene and other α-olefins using a radical initiator under high pressure and high temperature, or an ethylene-α-olefin copolymer may be further added.
The copolymer preferably has an MFR of about 20 to 300, and more preferably about 50 to 150.

  An antistatic agent or a conductive substance (conductive filler) may be added to the joint material in order to improve conductivity. Examples of the antistatic agent include quaternary alkyl allyl ammonium salts, quaternary alkyl ammonium salts, alkyl amines, alkyl ether amines, and the like, and examples of conductive substances include carbon black, zinc oxide, tin oxide, and aluminum. A powder etc. are mentioned.

  In the present invention, as the joint material, a non-conductive polymer such as a thermoplastic polyolefin resin added with the above conductive filler can be used.

Next, a method for constructing a conductive floor will be described.
In the construction method of the present invention, a plurality of the above flooring materials are used, and each flooring material is disposed on the floor in close proximity with a gap therebetween. Each flooring should be such that the surface material film layer ("1" and "1 '" in FIG. 1) is on top, and the back side is made of concrete using an adhesive (for example, epoxy and urethane adhesives) Adhere to the floor substrate (“5” in FIG. 1). Next, joint materials (“3” and “3 ′” in FIG. 1) are filled in the gaps between the floor materials. Since the static electricity charged in the surface material film layer is discharged to the floor base material through the joint material, the joint material must be filled so as to be in contact with both the surface material film layer and the floor base material.

  The present invention provides a simple construction method for a conductive floor that is simple in construction and can reliably discharge static electricity. The conductive floor of the present invention has excellent antistatic performance without adding an antistatic agent or a conductive substance for imparting conductivity to the surface material.

The flooring of the present invention can be used, for example, for flooring of precision parts factories such as semiconductor manufacturing factories, electronic device assembly factories, liquid crystal display device factories, or plasma display factories. In conventional flooring materials, it is necessary to add an organic antistatic agent or an inorganic conductive filler such as zinc oxide in order to increase the antistatic property. Depending on the conditions of use, organic antistatic agents may outgas and volatilize in clean room air to contaminate the air, and inorganic conductive fillers are simply attached to the film surface of the flooring. As a result, it was easy to peel off from the floor material surface, causing dust in the air. For this reason, conventional flooring materials have so far been used only in loose factories where the allowable range of fine particles is 1000 per cubic foot (ft ³ ) or more. In contrast, since the flooring of the present invention does not generate outgas and dust, the limit of the number of fine particles in the air is 10 / ft ³ class clean room (for example, semiconductor manufacturing factory, electronic device assembly factory) It can be used for flooring of precision parts factories such as liquid crystal display device factories or plasma display factories. By using the flooring of the present invention in these factories, the product can be prevented from being contaminated by outgas and dust, and the yield and quality of the product can be improved.

  In addition, the flooring of the present invention can be used as a flooring for buildings that require hygiene management such as hospitals, pharmaceutical factories, and bio-related facilities. For example, in the case of hospitals, bacteria and viruses are adsorbed on the floor surface by static electricity in conventional flooring, which may cause nosocomial infections, but the flooring of the present invention is not charged. There is no risk of bacteria or viruses adhering to the surface, and no problem of nosocomial infection occurs. Further, unlike the conventional flooring material, the plasticizer (also so-called environmental hormone) is volatilized from the inside of the flooring material and does not harm the health of the patient and the person in the hospital. Similarly, even when used in pharmaceutical factories and bio-related facilities, it is possible to provide a production environment with excellent cleanliness because no outgas or dust is generated.

  In addition, the flooring of the present invention should be used for flooring in classrooms such as nurseries, kindergartens, schools, universities, and vocational schools where infants, students and students gather, and in halls and auditoriums where many people gather. Can do. In the case of the conventional flooring, since many antistatic agents are added to impart antistatic properties to the surface material, there is a risk of air contamination due to volatilization of the additive into the air. On the other hand, the flooring of the present invention has sufficient antistatic performance without adding an antistatic agent, and also requires a plasticizer that becomes an environmental hormone such as a conventional PVC flooring. Therefore, since these outgasses do not occur, it is safe to use for flooring materials such as classrooms and halls. In addition, in the classrooms and halls where many students come and go, cotton dust due to fibers from clothes is generated. However, since the flooring of the present invention is antistatic, it is caused by the adhesion of these cotton dust to the floor. It is possible to prevent the floor surface from being soiled.

  Moreover, the flooring of this invention can be used for floor surfaces of houses, such as detached houses and apartment houses. Since the floor surface is prevented from being soiled due to adhesion of cotton dust or the like to the floor, the floor can be kept clean. In addition, in families with infants and children whose resistance to chemical substances is only about 1/3 that of adults, it is particularly important to use flooring that does not produce outgas and environmental hormones for the healthy development of infants and children. . In addition, not only for infants and children, but also for adults, if they stay in a house where outgas and environmental hormones exist even in trace amounts, they may accumulate in the body, so the flooring of the present invention Is preferably used.

  Furthermore, the flooring of the present invention can be used on the floor of a factory that handles powder. Examples of the factory handling the powder in the present invention include a food mill, a resin kneading factory, a chemical mill, and the like. In factories that handle powder, it was a problem that the powder charged in the air and charged with static electricity adhered to the floor surface and contaminated the floor surface. However, if the floor material of the present invention is used, the powder The floor is always kept clean without sticking to the surface.

  As described above, the flooring of the present invention not only has practicality such as durability, abrasion resistance, adhesion to the floor base, etc., but also has no outgassing or additive scattering and is non-chargeable. Therefore, the dust is less adsorbed and the environment is kept clean. Therefore, the flooring of the present invention is useful as a flooring for semiconductor factories, pharmaceutical factories and schools.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by an Example.
The physical properties of the flooring were evaluated as follows.

Measurement of Outgas (Organic) Amount of Floor Material The amount of outgas generated from a resin film or floor material was measured by a dynamic headspace / gas chromatogram / mass spectrum (DHS / GC / MS) method. In order to vaporize volatile components in the sample, the sample was heated at 150 ° C. for 30 minutes while flowing helium gas through the sample in the sample holder. Outgas which had been vaporized in helium by heating was introduced into a Tenax tube (GESTEL) and adsorbed. The outgas collected in the adsorption tube was passed through the GC / MS apparatus and the type and amount were measured. The column of the gas chromatogram apparatus was a capillary column (liquid layer: phenylmethylsiloxane), the length was 60 m, and the measurement temperature was from room temperature to 280 ° C. An analyzer manufactured by Agilent Technologies was used as the DHS / GC / MS apparatus.

Walking chargeability test The flooring materials obtained in the following examples were cut into 300 mm squares, and four pieces were prepared by attaching them to a 300 mm square concrete floor board with an epoxy resin adhesive. This specimen was placed in a clean room maintained at a temperature of 23 ° C. and a humidity of 40%. As the walking electrification measuring device, Statilon DS manufactured by Sicid Electrostatic Co., Ltd. was used.

  A measurement terminal of a walking electrification measuring device is attached to a test subject wearing clean clothes (manufactured by Gardner) that are worn in a clean room of a semiconductor or liquid crystal device manufacturing factory and anti-static walking shoes (manufactured by Gardner). Attach to the floor for 30 seconds. This action generates and accumulates static electricity in the person under test. Static electricity generated in the test subject is transmitted from the test subject's feet to the floor through antistatic shoes. If the flooring material can sufficiently discharge static electricity, the static electricity accumulated in the pedestrian will be discharged through the flooring material, so the amount of static electricity that accumulates in the test subject will be small. By measuring the amount, the antistatic performance of the flooring can be evaluated.

Example 1
As the ethylene-acrylic acid copolymer of the film layer for the surface material, trade name “HIMIRAN” resin manufactured by Mitsui DuPont Chemical Co., Ltd. (ethylene: acrylic acid = 85 mol%: 15 mol%, MFR = 0.5, surface resistance = 7.8 × 10 ⁷ Ω) The neutralized salt of calcium of the above copolymer (neutralization rate 30 mol%, unneutralization rate 70%, Surface resistance value = 2.5 × 10 ¹² Ω) was used. These resins were simultaneously extruded by extruding two kinds of resins from separate dies into a sheet shape by a co-extruder to produce a sheet-like floor material used in the examples of the present invention. The outgas amount of this flooring was measured by the above method, and the measurement results are shown in Table 1.

The sheet-like flooring manufactured by the above method is adhered to the floor base using an epoxy resin adhesive (E250) manufactured by Konishi Bond on the concrete floor base, and the conductive floor sheet of the present invention is applied. A resin sheet affixed floor that was not filled with joints was constructed. In a separate adhesion test (performed in accordance with JIS A5536: 2003), it was found that the adhesion strength between the flooring material and the concrete base was 1.3 MPa / cm ² , which was sufficient. The concrete floor is grounded by attaching a copper wire to a hanging bracket and connecting it to a ground copper wire connected to a thick copper wire embedded in the ground.

Next, as a joint material for filling joints between a plurality of sheet-like floor materials constructed on the floor, a resin of potassium neutralized salt of ethylene-acrylic acid copolymer similar to the film layer for the surface material (resistance value 2.5) x10 ⁸ Ω), MFR = 100). This resin was extruded into a string shape having a diameter of 3 mm with an extruder and wound up to obtain a joint material used in the present invention. Next, the joint material between the plurality of sheet-like floor materials applied to the floor is filled so that the joint material is attached to the floor base, and the joint material obtained by heating and melting is a film layer for the surface material of the sheet-like floor material. The flooring was constructed so as to be in contact with the floor.

  The chargeability of the floor to which the long resin sheet thus obtained was attached was evaluated by the above-mentioned walking charging test method, and the results are shown in Table 1.

  From the results of Table 1, it was found that the floor by the floor construction method of the present invention has a small value of walking electrification and can be used sufficiently. It was found that the walking charge of the human body is transmitted from the shoes to the floor material surface, from the floor surface to the building body through the joint material, and then discharged to the ground through the ground wire attached to the building.

(Example 2)
Using a metal salt resin of ethylene / (meth) acrylic acid copolymer resin (made by Mitsui / DuPont Polychemical Co., Ltd., trade name: Himiran) as the raw material for the film layer for the surface material, the zinc salt resin (Himiran 1650) 50 weight % And a potassium salt resin (High Milan) 50% by weight were formed into a sheet shape to obtain a film layer for a surface material (surface resistance 7.2 × 10 ⁷ Ω) used in the present invention. Next, as the intermediate layer, an olefin-based thermoplastic elastomer (Mitsui Chemicals, trade name: Miralastomer) formed into a sheet by extrusion was used. As a film layer for the back material, ethylene- (meth) acrylic acid copolymer is used, and the zinc salt resin (Himiran 1650) is 50% by weight and is not neutralized at all (Du Pont, NUCREL, 50% by weight) %) Was molded into a sheet shape by an extruder.

In addition, as a joint material, 100 parts by weight of a zinc salt resin (Himiran 1650, electrical resistance: 10 ¹⁵ Ω or more) of a metal salt resin of ethylene / (meth) acrylic acid copolymer resin (Mitsui / DuPont Polychemical), As conductive polymer, 5 parts by weight of SSPY (ethyl 3-methyl-4-pyrrolecarboxylate and butyl 3-methyl-4-pyrrolecarboxylate) manufactured by TAE Chemical Co., Ltd. and dopant TCNA (2,3,6,7-tetracyano) -1,4,5,8-tetraazanaphthalene) and 0.5 parts by weight (resistance value 2.5 × 10 ⁸ Ω) were used. This resin was extruded into a string shape having a diameter of 3 mm with an extruder and wound up to obtain a joint material used in the present invention.

  Fill the joints between the plurality of sheet-like flooring materials applied to the floor so that the jointing material is attached to the floor base, and the jointing material that has been heated and melted becomes the film layer for the surface material of the sheet-like flooring material. It was constructed so as to come into contact.

  The charging property of the floor thus constructed was evaluated by the above-mentioned walking charging test method, and the results are shown in Table 1. As shown in the results of Table 1, it was found that the value of the walking charge was small and was effectively discharged through the flooring. It was also found that the amount of outgas generated from the flooring body was small.

Example 3
As a raw material for the film layer for the surface material, 100 parts by weight of an olefin thermoplastic elastomer (zinc salt of ethylene-acrylic acid copolymer, manufactured by Mitsui Chemicals, trade name Miralastomer) and SSPY manufactured by TAY Chemical Co., Ltd. as a conductive polymer (Ethyl 3-methyl-4-pyrrolecarboxylate and butyl 3-methyl-4-pyrrolecarboxylate) 5 parts by weight and dopant TCNA (2,3,6,7-tetracyano-1,4,5,8-tetraaza Naphthalene) with 0.5 parts by weight added thereto was formed into a sheet with a thickness of 100 μm using an extruder to form a surface layer. Further, as a film layer for the back material, an ethylene-vinyl acetate copolymer resin (Mitsui / DuPont Polychemical Co., Ltd., trade name EVAFLEX) added with calcium carbonate was extruded to a thickness of about 2 mm. There is no intermediate layer. The said surface material film layer and the back material film layer were continuously adhere | attached with the hot roll, and the flooring used for construction of this invention was obtained.

Next, the same joint material as that used in Example 2 was used as the joint material.
Floor materials were constructed in the same manner as in Examples 1 and 2.
Table 1 shows the results of the outgassing of the flooring material of Example 3 and the floor charging walking test. According to the results, it was found that the flooring according to the present invention has less outgas and less walking charge.

(Comparative Example 1)
The floor material used in the comparative example is Roncleanlium LS (trade name, manufactured by Ronceal) whose main material is polyvinyl chloride, and its surface layer is vinyl chloride to which calcium carbonate and an organic antistatic agent are added. Resin. The back layer is also a vinyl chloride resin to which calcium carbonate and an organic antistatic agent are added. For the joint material, we used vinyl chloride joint material provided by the company and constructed a floor with vinyl chloride sheet.

  In the walking electrification test, it was found that this flooring material was excellent in antistatic properties, but as a result of analysis of this flooring material, it was found that it contained a phthalate ester plasticizer as an environmental hormone. Moreover, it turned out that the amount of outgas has the problem that there are many generation | occurrence | production amounts compared with the flooring of this invention. Furthermore, since polyvinyl chloride is used, there is an essential problem that dioxins are produced during incineration.

(Comparative Example 2)
A surface layer is formed by molding a resin in which 100 parts by weight of an olefinic thermoplastic elastomer (Mitsui Chemicals, trade name: Miralastomer) and 1 part by weight of an organic antistatic agent (trade name: electro stripper) is added to a sheet. Further, a sheet obtained by molding a resin obtained by adding calcium carbonate and an organic antistatic agent to an olefinic thermoplastic elastomer (same as above) was used as a back layer. There is no intermediate layer. These surface material and back surface material were pressed and integrated with a hot roll to obtain a flooring. The joint material used in Example 2 was tried.

When the outgas amount of the flooring was measured, it was found that the amount generated was large. Further, it was found that the organic antistatic agent cannot exhibit sufficient antistatic performance and has high walking chargeability.
Table 1 shows the flooring materials used in the above Examples and Comparative Examples and the experimental results.

  According to the present invention, it is possible to provide a conductive floor which is excellent in antistatic property, has less outgas, is friendly to the environment and people, has a simple configuration, and a simple construction method thereof. The flooring of the present invention is useful as a flooring for facilities requiring a clean environment, such as precision parts factories such as semiconductor factories, hospitals, and schools.

FIG. 1 is a cross-sectional view of the conductive floor of the present invention.

Explanation of symbols

1 and 1 '... surface material film layers 2 and 2' ... intermediate layer and / or back material film layers 3 and 3 '... joint material 4 ... adhesion Agent 5 ... Floor base

Claims (5)

A plurality of flooring materials having a surface material film layer having a surface resistance value of 10 ⁹ Ω or less, which is bonded to a floor ground made of electrically grounded concrete with an epoxy or urethane adhesive, and the surface material And a joint material having a resistance value of 10 ⁹ Ω or less filled in a gap between the floor materials so as to be in contact with both the film layer and the floor substrate, and the static electricity charged on the surface material film layer is A conductive floor that is discharged to the floor base through a joint material.   The joint material is a copolymer of a carboxyl group-containing unsaturated monomer and an α-olefin monomer, wherein the carboxyl group is partially a salt with a monovalent and / or divalent metal. The conductive floor according to claim 1, wherein the conductive floor is a resin containing   At least one monovalent and / or divalent metal selected from the group consisting of potassium, sodium, lithium, calcium, magnesium and zinc, 30 to 90% of the carboxyl groups in the copolymer of the joint material The conductive floor according to claim 2, wherein the conductive floor is a salt.   The conductive floor according to claim 1, wherein the joint material is a non-conductive polymer to which a conductive filler is added. Adhering a plurality of flooring materials having a surface material film layer with a surface resistance value of 10 ⁹ Ω or less to a floor ground made of electrically grounded concrete using an epoxy or urethane adhesive, and then the resistance value Filling a gap between the flooring materials with a joint material of 10 ⁹ Ω or less so as to be in contact with both the surface material film layer and the floor base, and charging the surface material film layer with the static electricity A method for constructing a conductive floor through which the floor is discharged.

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