JPH08273883A - Antistatic body - Google Patents

Abstract

PURPOSE: To provide an antistatic body having high strength, heat resistance and fire resistance by making a hydraulic antistatic body composition contain blast furnace slag, water soluble high polymer, alkaline substance, and conductive substance. CONSTITUTION: A hydraulic antistatic body composition contains blast furnace slag, water soluble high polymer, alkaline substance, and conductive substance. The composition composed of the blast furnace stag, the water soluble high polymer, the alkaline substance, the conductive substance, and water is kneaded and molded, and thereafter, is wet-cured so as to form an antistatic body. Or, the composition composed of the blast furnace slag, the water soluble high polymer, the alkaline substance, and the water is kneaded, and thereafter, is composite-molded with the conductive substance so as to form the antistatic body.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antistatic body.

[0002]

2. Description of the Related Art In recent years, with the development of electronics technology, various electronic devices such as personal computers and word processors have been introduced in many factories, offices, general houses and the like. The harmful effects caused by the static electricity generated from these electronic devices being charged in the use space, such as malfunction of electronic devices and functional damage to the human body, have been highlighted. Further, a clean room device is used for preventing dust generation in a manufacturing factory or a handling place of electronic devices, foods or pharmaceuticals, but a cheaper system is required. In solving the above-mentioned problems, there is a plate-shaped composite of a conductive substance and a matrix such as resin or concrete.

[0003]

When a conductive substance is combined with a matrix such as a resin, the resulting antistatic body is inferior in heat resistance and fire resistance. Further, when an inorganic material such as cement is used as a matrix, it is difficult to obtain sufficient strength.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above-mentioned problems. That is, the present invention includes (1) a blast furnace slag, a water-soluble polymer, an alkaline substance, and a hydraulic antistatic body composition containing an electrically conductive substance, (2) a blast furnace slag, a water-soluble polymer,
An antistatic body obtained by kneading a composition consisting of an alkaline substance, a conductive substance and water, molding and then wet curing, and (3) kneading a composition consisting of blast furnace slag, a water-soluble polymer, an alkaline substance and water. After that, a composition comprising an antistatic body formed by composite molding with a conductive material, (4) blast furnace slag, a water-soluble polymer, an alkaline material, and water was kneaded, and then composite molded with the conductive material. Provided is an antistatic body obtained by wet curing a molded body.

The present invention will be described in detail below. In the present invention, the blast furnace slag is a product obtained by pulverizing and drying a glassy substance obtained by rapidly cooling molten slag produced simultaneously with pig iron in a blast furnace with water or air, and generally has a Blaine value of 2000 cm ² Those having a specific surface area of / g or more can be used. Also, the Blaine value is 4000c
It is also possible to use a relatively coarse blast furnace slag of m ² / g or less and a fine blast furnace slag having a Blaine value of 5000 cm ² / g or more.

The water-soluble polymer used in the present invention is not particularly limited, but it is preferable that the water-soluble polymer be uniformly and rapidly dissolved in the kneaded product in the kneading step described below, and therefore fine particles are preferable. The water-soluble polymers that can be used in the present invention are exemplified below. (A) Water-soluble polymers having a carboxyl group and / or an amide group in the molecule, or salts thereof, homopolymers or copolymers of α-hydroxy-sodium polyacrylate and the following monomers as raw materials, or salts thereof.

The above-mentioned monomer raw materials include acrylic amide, N, N-dimethyl acrylic amide, N
-(Meth) acrylic amide-based monomers such as methyl acrylic amide, (meth) acrylic acid, sodium (meth) acrylate, potassium (meth) acrylate, (meth)
Lithium acrylate, (meth) acrylic acid type monomers such as 2-hydroxyethyl (or propyl) (meth) acrylate, vinyl such as N-vinylpyrrolidone, vinyl methyl ether, styrene sulfonic acid (or their sodium or potassium salts) System monomer. Also, poly (meta)
A partial hydrolyzate of acrylic amide can also be used.

(B) Cellulose derivatives such as hydroxypropylmethylcellulose, hydroxyethylmethylcellulose and carboxymethylcellulose. (C) Polyvinyl acetate derivatives such as partially hydrolyzed polyvinyl acetate, cationized polyvinyl acetate and anionized polyvinyl acetate. (D) Soluble starch. (E) Polyethylene oxide. (F) Copolymers of (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and propyl (meth) acrylate, styrene, ethylene, propylene and the like with the above water-soluble monomer.

Among these water-soluble polymers, particularly preferred are sodium poly (meth) acrylate, potassium poly (meth) acrylate, poly (meth) acrylamide, partial hydrolyzate of poly (meth) acrylamide, or a product thereof. Examples thereof include salts, copolymers of sodium (meth) acrylate and (meth) acrylamide, copolymers of potassium (meth) acrylate and (meth) acrylamide, polycarboxymethyl cellulose and the like. These (meta)
The molecular weight of acrylic acid or a salt thereof or a copolymer of (meth) acrylamide and (meth) acrylic acid salt is preferably 10,000 or more.

The amount of the water-soluble polymer used in the present invention is not particularly limited, but is 1 to 25% by weight, preferably 2 to 10% by weight based on the blast furnace slag. When the amount of the water-soluble polymer used is 1% by weight or less, the mixture cannot be kneaded, or even if the mixture can be kneaded, the moldability of the subsequent step tends to be poor. Further, even if it is used in an amount of 25% by weight or more, the bending strength and water resistance of the obtained composite material are not significantly changed, which is economically disadvantageous.

The alkaline substance used in the present invention is not particularly limited as long as it dissolves in water and exhibits alkalinity. For example, sodium hydroxide, potassium hydroxide,
Alkali metal hydroxides such as lithium hydroxide, alkali metal carbonates such as sodium carbonate, potassium carbonate and lithium carbonate, alkali metal bicarbonates such as sodium bicarbonate, potassium bicarbonate and lithium bicarbonate, and hydroxides. Alkaline earth metal hydroxides such as calcium and magnesium hydroxide, alkaline earth metal oxides such as calcium oxide and magnesium oxide, and Portland cement, Portland cement clinker, potassium pyrophosphate, sodium pyrophosphate and diphosphate. Examples include potassium, tripotassium phosphate, trisodium phosphate, potassium metasilicate, sodium metasilicate and the like. Particularly preferable examples of these alkaline substances are sodium hydroxide, sodium carbonate, sodium metasilicate, Portland cement clinker and the like.

The amount of these alkaline substances used is not particularly limited and varies depending on the basicity of the alkaline substance and the amount of water added, but it is usually 0.1 to blast furnace slag.
It is 5% by weight, preferably 0.2 to 3% by weight.
When the amount of the alkaline substance used is 0.1% by weight or less, the molded body does not cure even by wet curing, or even if it cures, wet curing (curing) requires a long time, which is industrially disadvantageous. On the other hand, if an alkaline substance is used in an amount of 5% by weight or more, the curing may be too fast and the curing may proceed during the kneading / molding process. As described above, the present invention is characterized in that the blast furnace slag is hardened even if the amount of the alkaline substance used is extremely small.

The conductive substance used in the present invention can be roughly classified into metal and carbon substances. The metal is not particularly limited, and a simple substance made of one kind of element such as aluminum, chromium, iron, cobalt, nickel, copper, zinc, molybdenum, lead, tin and an alloy made of two or more kinds of elements are used. Specific examples thereof include steel, aluminum alloy, copper, brass, bronze, stainless steel, permalloy, and the like.

The carbon material is not particularly limited, but artificial (natural) graphite powder, carbon black (acetylene black, Ketjen black, finesse black, etc.), carbon fiber powder, polymer carbon powder, mesophase pitch type graphite powder, Specific examples of the composite carbon / graphite powder and the like can be used. Among them, natural graphite powder, carbon fiber powder and the like are exemplified as preferable ones.

The shapes of these conductive materials are not particularly limited, and various shapes of conductive materials can be used. As fine particles, amorphous, spherical, short fiber, flat, plate-like, etc., as fibrous materials, single fiber, long fiber,
Examples of the sheet-like material such as a fiber-based material, a fiber-woven material, and the like include foil, paper, felt, and the like. Further, these conductive materials may be used alone or in combination of two or more kinds.

The amount of the conductive material added is not particularly limited and is usually 0.005 to 2000% by weight, preferably 0.01 to 1000% by weight, based on the blast furnace slag.

The amount of water added to obtain the antistatic body of the present invention varies depending on the amount of water-soluble polymer added, the type and amount of alkaline substance, the type and shape of conductive substance, and the amount added, and a good mixture is obtained. It should be determined so as to show kneadability, and usually 5 to 100% by weight, preferably 10 to 50% by weight, based on the blast furnace slag.

In order to secure the physical strength of the antistatic body of the present invention, a fine aggregate may be used. The fine aggregate is not particularly limited as long as it is generally available, but silica fume, fly ash, silica sand, silica sand powder, silica stone powder,
Examples include clay, talc, kaolin, calcium carbonate, titania, zirconia, alumina and the like. These fine-grained aggregates function as a filler for voids in the antistatic body of the present invention. Whether or not they are used depends on whether the kneaded product is improved in workability during molding and is hardened as described below. This may affect the reduction of shrinkage due to drying. Among these fine aggregates, silica fume is preferable.

Further, it is preferable that the fine aggregate has a smaller particle diameter, and it is particularly preferable that the average particle diameter is 100 μm or less.
Further, the addition amount of the fine aggregate is 2 to 50 with respect to the blast furnace slag.
%, More preferably 5 to 30% by weight. For the purpose of improving the toughness of the cured product after molding and curing of the hydraulic composition and the composite material of the present invention, a fibrous substance such as glass fiber, carbon fiber or vinylon fiber can be added.

In the present invention, a curing retarder may be added for the purpose of ensuring a sufficient working time in the kneading and molding steps. As the curing retarder which can be used, gluconic acid, tartaric acid, malonic acid, succinic acid, maleic acid, fumaric acid, malic acid, formic acid, sodium salt or potassium salt of acetic acid, glucose, fructose, sucrose, lactose, maltose. Examples thereof include sugars, and the amount used is not particularly limited, but is preferably 0.1 to 10% by weight with respect to the blast furnace slag.

The shape of the antistatic body of the present invention is not particularly limited, but when it is used as a sheet antistatic plate, it may be formed into a plate shape, or may be molded into various shapes by a casting method, or a composition. It is also possible to use as a planar antistatic paste. When used in the form of a plate, the thickness thereof is 0.1 mm to 500 mm, particularly preferably 1 mm to 5 mm.
Set to 0 mm.

Next, the hydraulic antistatic composition and the method for producing the antistatic material of the present invention will be described, but the present invention is not limited thereto. (A) A method for producing the hydraulic antistatic composition according to (1) above. A mixture of blast furnace slag powder, a water-soluble polymer, an alkaline substance, a conductive substance and, if necessary, a fine aggregate and a curing retarder is prepared, The hydraulic antistatic composition of the present invention can be obtained by mixing in a powder form with an oscillating mixer such as Omni Mixer (manufactured by Chiyoda Giken Kogyo Co., Ltd.), a kneader ruder mixer, a planetary mixer or the like. In this case, the conductive substance is preferably powdery or fibrous.

(B) Method for Producing Antistatic Body as Described in (2) First, a mixture of blast furnace slag powder, water-soluble polymer, electrically conductive substance and, if necessary, fine aggregate is prepared, and exemplified in (A) above. The mixture is mixed using the mixer described above.
Next, an aqueous solution in which a predetermined amount of water and an alkaline substance (setting retarder if necessary) are dissolved is added to this mixture, and further rough kneading is performed. Further, a predetermined amount of water may be added to the hydraulic substance obtained in the above (A), and similarly rough kneading may be performed. In this case, the conductive substance is preferably powdery or fibrous.

After that, kneading is carried out, but it is desirable to use an apparatus capable of applying strong shear to the crude kneaded product. For example, a roll kneader, a Banbury mixer, a wet Banbury mixer, a mixing roll, a kunet machine, a bag mill, a screw extruder, a kneader ruder, etc. are used, and kneading is performed until the kneaded product has a clay-like appearance.

Next, the above kneaded product is molded by a suitable molding machine to obtain a molded product. There are no particular restrictions on the molding machine that can be used, and examples include calender rolls, (low to hard) pressure presses, and (vacuum) extruders. The antistatic body of the present invention is used as a cured body which is cured by the following wet curing step, but particularly when a method capable of molding under reduced pressure is adopted, it has a larger bending strength and a variation in bending strength. It is preferable because a small amount of cured product can be obtained.

The wet curing after molding is not particularly limited as long as at least a moisture atmosphere of the kneaded / molded product is not evaporated and a high wet atmosphere is achieved. Usually, the relative humidity is 80% or more, but preferably curing is performed in a humid atmosphere of 90% or more, a molded body is put in a water-impermeable container or bag, or a molded body is formed on a plastic plate or a metal plate. An example of a method of sandwiching is shown. It is also possible to immerse the molded body in the early stage of wet curing in water to perform curing in water.

In the wet curing in the present invention, the higher the temperature is, the faster the kneading / molding product cures, but there is no particular limitation. Usually, a temperature of room temperature to 100 ° C. is used.
Also, autoclave curing may be performed at 100 ° C. or higher using steam. The wet curing time depends on the type and amount of alkaline substance used and the wet curing conditions,
It is approximately 1 hour to 3 days.

Although the hardened body after wet curing contains water, it is preferably dried and used. The drying temperature is not particularly limited and can be arbitrarily selected in the temperature range of room temperature to 100 ° C., but it is preferable to gradually dry at a temperature close to room temperature over a period of time rather than drying at a high temperature. The antistatic body of the present invention can be obtained as described above.

(C) Method for Producing Antistatic Body According to (3) Above, in the same manner as in (B) above, blast furnace slag powder, water-soluble polymer, alkaline substance and, if necessary, fine aggregate and hardening retarder A mixture consisting of is prepared, and a molded product is obtained in the same manner as in (B). Next, a plate (sheet-like or net-like) conductive material is sandwiched between the two molded bodies, and the material is passed between two roll presses or lightly pressed by the press to integrate the two, thereby forming a book. The antistatic body of the invention can be obtained.

(D) Further, the antistatic body obtained in (C) above is wet-cured in the same manner as in (B) above to obtain the antistatic body described in (4) above.

[0031]

The present invention will be described below with reference to examples.
The present invention is not limited to this.

Example 1 Preparation of Antistatic Hydraulic Composition Blast furnace slag powder (manufactured by Nippon Steel Chemical Co., Ltd., ESMENT 40)
P (Blaine value, 4000 cm ² / g)); 180 parts by weight, sodium bicarbonate; 2 parts by weight, silica fume (manufactured by Nippon Heavy Chemical Industry Co., Ltd., SF powder); 20 parts by weight,
Sodium polyacrylate (manufactured by Nippon Kayaku Co., Ltd., Panakayak-B); 6 parts by weight, B-800 (natural graphite powder, manufactured by Nippon Carbon Co., Ltd.); 60 parts by weight and sugar; 0.2 parts by weight The mixture was mixed in a vinyl bag to obtain the hydraulic antistatic composition of the present invention.

Example 2 The hydraulic charging of the present invention was carried out in the same manner as in Example 1 except that 90 parts by weight of flake graphite (manufactured by Chuo Kasei Co., Ltd.) was used instead of B-800. An inhibitor composition was obtained.

Example 3 Preparation of Antistatic Body Essment 40P; 180 parts by weight, SF powder; 20
Parts by weight, Panakayak-B; 6 parts by weight, B-800; 60
Part by weight was weighed and put in a polyethylene bag for powder mixing. Next, 2 parts by weight of sodium hydroxide and 0.2 parts by weight of sugar were added to an aqueous solution of 32 parts by weight of water, and the mixture was lightly kneaded from the top of the bag to obtain a coarse kneaded product.

Then, this crude kneaded product was kneaded with a tabletop kneader (PBV-0.3, manufactured by Irie Shokai Co., Ltd.) for 5 minutes under high shearing force to obtain a dough. This dough was prepared into a plate-shaped molded product having a thickness of 3 mm using a hot platen press (manufactured by Tester Sangyo Co., Ltd.). This molded body was placed in a polyethylene bag, placed in a curing chamber at 90% relative humidity and 90 ° C., and wet-cured for 24 hours to obtain an antistatic body of the present invention. This cured product was taken out of the polyethylene bag and was 15 mm in a band sawing machine (Luxor V-19 type DIA).
It was cut into a plate of × 60 mm to obtain an antistatic measurement sample (BH-1).

The antistatic effect was evaluated by pressing a measuring probe of a digital multimeter (R6441A, manufactured by Advantest Co., Ltd.) against the sample surface at a probe interval of 1 cm to obtain an antistatic body of the present invention. as a result,
The antistatic effect of BH-1 was 500Ω.

The above sample; BH-1 is 15 mm
It was cut into a plate of × 100 mm and used as a sample for measuring bending properties. Bending properties were measured using Tensilon (UT-2500, manufactured by Orientec Co., Ltd.) with a span interval of 60 m.
m, bending speed 1 mm / min, bending strength; 300 kgf / cm ² , bending elastic modulus; 1.0 × 10
^{It was 5} kgf / cm ² .

Examples 4 to 7 In Example 3, the conductive material shown in Table 1 was added in place of B-800, and the same operation as in Example 1 was carried out to prepare the antistatic body of the present invention. did. Table 2 shows the antistatic effect measured on the obtained antistatic body in the same manner as in Example 3.

[0039]

Table 1 Table 1 Conductive substance Addition amount (parts by weight) Example 4 (BH-2) B-800 90 Example 5 (BH-3) B-800 180 Example 6 (BH-4) R-1 60 Example 7 (BH-5) RIN 60

In Table 1, R-1 is natural graphite (manufactured by Nippon Carbon Co., Ltd., powder form) RIN: Flake graphite (manufactured by Chuo Kasei Co., Ltd.).

[0041]

[Table 2]

Example 8 Essment 40P; 180 parts by weight, SF powder; 20
Parts by weight, Panakayak-B; 6 parts by weight, B-800; 60
Part by weight was weighed and put in a polyethylene bag for powder mixing. Next, 2 parts by weight of sodium hydroxide and 0.2 parts by weight of sugar were added to an aqueous solution of 32 parts by weight of water, and the mixture was lightly kneaded from the top of the bag to obtain a coarse kneaded product.

Next, this crude kneaded material was kneaded with a roll kneader for 5 minutes under a high shearing force to obtain a dough. This dough was depressurized to 30 mmHg using a vacuum extruder (HDE-3 manufactured by Honda Iron Works Co., Ltd.), and the extrusion speed was 60 cm.
/ Min to prepare a plate-shaped molded product having a thickness of 4 mm and a width of 100 mm. This molded body was placed in a polyethylene bag and placed in a curing chamber at 90% relative humidity and 90 ° C. for wet curing for 24 hours.
This cured product was taken out of the polyethylene bag and was used as a band sawing machine (Laxau Co., Ltd., V-19 type DI).
A) was cut into a plate shape of 15 mm × 60 mm to obtain an antistatic measurement sample (BH-6).

As a result of evaluating the antistatic effect and the bending strength as in Example 3, the antistatic effect of BH-1 was 45.
It was 0Ω, the flexural strength was 600 kgf / cm ² , and the flexural modulus was 1.5 × 10 ⁵ kgf / cm ² .

As described above, the composite material obtained by kneading and molding the composition comprising the blast furnace slag, the water-soluble polymer, the alkaline substance, the conductive substance, and water, and then wet-curing the mixture has an antistatic effect and high strength. I found that.

Example 9 Essment 40P, 180 parts by weight, SF powder, 20
6 parts by weight of Panakayak-B was weighed and placed in a polyethylene bag for powder mixing. Next, sodium hydroxide, 2 parts by weight, and sugar, 0.2 parts by weight of water, 32 parts
An aqueous solution dissolved in parts by weight was added, and the mixture was lightly kneaded from the top of the bag to obtain a coarse kneaded product.

Next, this crude kneaded product was mixed with a table-type kneader for 5 minutes.
The mixture was kneaded for a minute under high shearing force to obtain a dough. This dough was prepared into a plate-shaped molded product having a thickness of 1 mm and 2 mm using a hot platen press. A carbon sheet was sandwiched between this molded body and press-molded. This molded body was placed in a polyethylene bag, placed in a curing chamber at 90% relative humidity and 90 ° C., and wet-cured for 24 hours to obtain an antistatic body of the present invention. This cured product was taken out from a polyethylene bag and cut into a plate shape of 15 mm × 60 mm with a band sawing machine to obtain a surface antistatic measurement sample (SH-1).

When the SH-1 matrix was partially destroyed and the carbon sheet sandwiched therein was exposed and the antistatic effect was measured, it was 80Ω.

Comparative Example 1 Essment 40P; 180 parts by weight, SF powder; 20
6 parts by weight of Panakayak-B (part by weight) were weighed and put in a polyethylene bag for powder mixing. Next, sodium hydroxide; 2 parts by weight, and sugar; 0.2 parts by weight of water; 32
An aqueous solution dissolved in parts by weight was added, and the mixture was lightly kneaded from the top of the bag to obtain a coarse kneaded product.

Then, this crude kneaded product was put in a table-type kneader,
The mixture was kneaded for 5 minutes under a high shearing force to obtain a dough. Using a hot platen press, this dough was prepared into a plate-shaped molded product having a thickness of 3 mm. This molded body was placed in a polyethylene bag and placed in a curing chamber at 90% relative humidity and 90 ° C. for wet curing for 24 hours.
The cured product was taken out of the polyethylene bag and cut into a plate of 15 mm × 60 mm with a band sawing machine to obtain a sample (AH-1).

As a result of evaluating the antistatic effect and the bending strength in the same manner as in Example 3, the antistatic effect of AH-1 was 15
The flexural strength was 0 MΩ, the flexural strength was 380 kgf / cm ² , and the flexural modulus was 1.2 × 10 ⁵ kgf / cm ² .

Comparative Example 2 Essment 40P; 180 parts by weight, SF powder; 20
6 parts by weight of Panakayak-B (part by weight) were weighed and put in a polyethylene bag for powder mixing. Next, sodium hydroxide; 2 parts by weight, and sugar; 0.2 parts by weight of water; 32
An aqueous solution dissolved in parts by weight was added, and the mixture was lightly kneaded from the top of the bag to obtain a coarse kneaded product.

Next, this crude kneaded material was kneaded with a roll kneader for 5 minutes under a high shearing force to obtain a dough. This dough was depressurized to 30 mmHg using a vacuum extruder (HDE-3 manufactured by Honda Iron Works Co., Ltd.), and the extrusion speed was 60 cm.
/ Min to prepare a plate-shaped molded product having a thickness of 4 mm and a width of 100 mm. This molded body was placed in a polyethylene bag and placed in a curing chamber at 90% relative humidity and 90 ° C. for wet curing for 24 hours.
This cured product was taken out of the polyethylene bag and was used as a band sawing machine (Laxau Co., Ltd., V-19 type DI).
A) was cut into a plate of 15 mm × 60 mm to obtain an antistatic measurement sample (AH-2).

The antistatic effect and the bending strength were evaluated in the same manner as in Example 3. As a result, the antistatic effect of AH-1 was 15
It was 0 MΩ, the bending strength was 860 kgf / cm ² , and the bending elastic modulus was 2.0 × 10 ⁵ kgf / cm ² .

[0055]

INDUSTRIAL APPLICABILITY The antistatic body of the present invention has heat resistance and fire resistance, has high strength, and the specific gravity of the matrix is about 2, and as a result, the weight of the material can be reduced. . Therefore, it is an effective material for indoor and outdoor planar antistatic bodies.

Claims (4)

[Claims] 1. A hydraulic antistatic composition containing blast furnace slag, a water-soluble polymer, an alkaline substance, and a conductive substance. 2. An antistatic body obtained by kneading and molding a composition comprising blast furnace slag, a water-soluble polymer, an alkaline substance, a conductive substance, and water, and then wet-curing the composition. 3. An antistatic body obtained by kneading a composition comprising blast furnace slag, a water-soluble polymer, an alkaline substance, and water, and then forming a composite with a conductive substance. 4. An antistatic body obtained by kneading a composition consisting of blast furnace slag, a water-soluble polymer, an alkaline substance, and water, and then wet-curing a molded body obtained by composite molding with a conductive material.