JP2011251875A - Electric-resistant stone material and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric-resistant stone material that shows little deterioration of electric resistivity by wear and is free of environmental and toxicological problems, and a method for manufacturing the same.SOLUTION: The electric-resistant stone material is manufactured by depositing a composition comprising (A) 100 pts.mass organopolysiloxane containing at least three Si-H bonds within the molecule and (B) 0.0001-10 pts.mass platinum catalyst onto a surface of a dried natural stone having a particle size of 5-50 mm and subjecting the same to a heat treatment. The dried natural stone acquires water repellency and water non-retentivity through a water-repellent silicone layer free of environmental and toxicological problems and thus never contains water and repels water when being walked on by humans or exposed to water, thereby retaining high electric resistance for a long period of time. Step voltage or contact voltage can be reduced by placing the natural stone around electrical facilities etc.

Description

  The present invention relates to an electric resistance stone material that maintains a high electric resistance value for a long period of time and a method for manufacturing the same.

  In maintenance / inspection / management of electric power, communication, railways, etc., it is necessary to secure a safe working environment that protects workers from electric shock. And as one method for that purpose, electric clothes for outdoor activities for protecting the body from lightning strikes have been proposed (Japanese Patent Laid-Open No. 6-235102: Patent Document 1). It is conceivable to prevent electric shock.

  By the way, in the vicinity of facilities such as electric power, communications, and railways, ground fault currents may be discharged to the ground to ensure safety in the event of abnormal voltage, etc. Voltage or contact voltage may be applied. Note that the stride voltage is a voltage that occurs between two points on the surface of the ground due to the slope of the ground potential when a large current flows through the ground electrode, and is thereby applied between both legs of the human body. When a large current flows through the grounding electrode, due to the slope of the ground potential, a potential difference occurs between the grounded object and the ground surface slightly away from the object, and the voltage applied to the human body when the human body comes in contact with the grounded object It is. In order to prevent these, it is conceivable to use electric clothes, etc. However, wearing special electric clothes at all times has problems such as a decrease in workability, and also ensures more safety. For this purpose, it is desirable to reduce the stride voltage and the contact voltage. The inventors of the present invention have proposed that a natural stone surface treated with a silicone water-repellent coating is effective as an electric resistance stone material capable of reducing the step voltage and the contact voltage (Japanese Patent Laid-Open No. 2007-191371). Publication: Patent Document 2). However, there is a problem in durability of the effect on wear. Furthermore, since the coating film made of Si—H containing siloxane and tin catalyst shown as a specific example contains a tin compound, problems remain in terms of environment and toxicity.

  In addition, the present inventors have proposed water-repellent gravel treated with Si—H-containing siloxane and a platinum catalyst (Japanese Patent No. 3804759: Patent Document 3), but the knowledge of electrical resistance and wear resistance is not known. There was nothing at all.

JP-A-6-235102 JP 2007-191371 A Japanese Patent No. 3804759

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric resistance stone material which is less deteriorated due to wear of an electric resistance value and has no problem in terms of environment and toxicity, and a method for producing the same.

  As a result of intensive investigations to achieve the above object, the present inventors have obtained an organopolysiloxane containing at least three Si-H bonds in one molecule and a platinum catalyst, preferably a reaction control agent in addition to these. By attaching the composition as the main component to the surface of a dried natural stone having a particle size of 5 to 50 mm and heat-treating it at 50 to 250 ° C., it is possible to maintain a stable high electrical resistance for a long period of time. It has been found that an electric resistance stone material can be obtained which is laid around and effective in reducing the step voltage and contact voltage, and has led to the present invention.

Accordingly, the present invention provides the following electric resistance stone material and method for producing the same.
Claim 1:
(A) Organopolysiloxane containing at least three Si-H bonds in one molecule
100 parts by mass,
(B) Platinum catalyst An electric resistance stone material obtained by adhering a composition containing 0.0001 to 10 parts by mass to the surface of dry natural stone having a particle size of 5 to 50 mm and heat-treating it.
Claim 2:
The electric resistance stone material according to claim 1, wherein the composition further comprises 0.01 to 10 parts by mass of (C) a reaction control agent with respect to 100 parts by mass of component (A).
Claim 3:
(A) Organopolysiloxane containing at least three Si-H bonds in one molecule
100 parts by mass,
(B) Platinum catalyst An electrical resistance characterized by adhering a composition containing 0.0001 to 10 parts by mass to the surface of dry natural stone having a particle size of 5 to 50 mm and heat-treating at 50 to 250 ° C. Stone manufacturing method.
Claim 4:
The method for producing an electric resistance stone according to claim 3, wherein the composition further comprises 0.01 to 10 parts by mass of (C) a reaction control agent with respect to 100 parts by mass of component (A).
Claim 5:
A natural stone having a particle size of 5 to 50 mm is put into a rotating drum rotated by a rotation driving means, and the natural stone is dried and heated by a heating means attached to the rotating drum, and by a spraying means attached to the rotating drum. The method for producing an electric resistance stone material according to claim 3 or 4, wherein the natural stone is treated by spraying the composition according to claim 3 or 4.

According to the present invention, the water-repellent and non-water-retaining properties are obtained by the silicone water-repellent layer that is excellent in abrasion resistance and environmentally toxic, so even if a person walks or is exposed to water, Dry natural stones do not contain water, can repel water, maintain high electrical resistance for a long time, and reduce the stride voltage and contact voltage by laying natural stones around facilities such as electricity can do.
In addition, an electric-related facility shows the facility which may discharge an electric current around electric power, communication, and a railway.
In this case, if a reaction control agent is contained in the composition, the curing reaction time during the treatment can be controlled, so that a uniform coating film can be imparted to the natural stone surface.

It is sectional drawing of the electrical resistance stone material which concerns on Example 1 of this invention. It is a side view of the manufacturing apparatus which made the part for obtaining the electric resistance stone material into the cross section. It is a top view of the manufacturing apparatus. It is sectional drawing explaining the example of use. It is a perspective view of an electrical resistance measuring device. It is a graph which compares the resistivity of the experimental product in Example 1, a comparative product, and sand. It is a graph which shows the moisture content of the same experimental product and a comparative product. It is a time chart figure explaining the manufacturing process.

  In the electric resistance stone material of the present invention, natural stones include granite, sandstone, slate, and river gravel is preferable. A particle diameter of 5 to 50 mm, particularly 20 to 40 mm is used. Even if the particle diameter is smaller than 5 mm or larger than 50 mm, the target ground resistance value may not be obtained. In addition, a particle size means an average outer diameter, and can be specifically measured with calipers.

Moreover, in the electric resistance stone material of the present invention, the organopolysiloxane (A) constituting the composition for treating natural stone is an organohydrogenpolysiloxane containing at least three Si-H bonds in one molecule, Any organohydrogenpolysiloxane containing at least three Si-H bonds in one molecule is not particularly limited, but those represented by the following general formula are preferred.
[SiO ₂ ] _p [RSiO _3/2 ] _q [R ₂ SiO] _r [R ₃ SiO _1/2 ] _s

  Here, R is a hydrogen atom, the same or different alkyl group having 1 to 20 carbon atoms, or an aryl group having 1 to 20 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, a butyl group, A pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a tetradecyl group, an octadecyl group, a phenyl group, a tolyl group, a naphthyl group and the like can be mentioned, but a methyl group is preferable except for a hydrogen atom. p, q, and s are each an integer of 0 or more, r is an integer of 3 or more, preferably p is 0 to 5, q is 0 to 10, s is 0 to 50, and r is 3 to 1,000. More preferably, p is 0 to 2, q is 0 to 5, s is 0 to 10, and r is 3 to 500.

  In the present invention, since the adhesion to the substrate is considered to be expressed by hydrogen atoms bonded to silicon atoms, the organopolysiloxane has a ratio of silicon atoms directly bonded to hydrogen atoms of 50% by mass. It is preferable that the amount be 70% by weight or more. The proportion of silicon atoms to which hydrogen atoms are directly connected may be 100% by mass. The molecular structure of this organopolysiloxane is not particularly limited and may be any of a chain, a branched, and a ring. From the viewpoint of workability, a viscosity at 25 ° C. is preferably 5 to 50,000 mPa · s, More preferably, it is 5 to 5,000 mPa · s. This viscosity is a value when a rotational viscometer is used.

Specific examples of such organopolysiloxanes include those represented by the following formulas (1) to (4).

  Of these, those of formulas (1) to (3) are preferred, and those of formula (1) are particularly preferred.

  Such an organopolysiloxane can be synthesized by a known method. For example, in the presence of a catalyst such as sulfuric acid, an Si-H bond-containing cyclic siloxane and a cyclic siloxane such as octamethylcyclotetrasiloxane, hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, etc. are equilibrated. It can be obtained by the chemical reaction. Moreover, it can also synthesize | combine by the conventionally well-known method by cohydrolysis condensation reaction, such as methyldichlorosilane, trimethylchlorosilane, and dimethylchlorosilane.

  Next, the platinum catalyst as the component (B) is blended to crosslink and cure the Si-H bond-containing organopolysiloxane. Specifically, for example, chloroplatinic acid, alcohol-modified chloroplatinic acid, chloride A platinum acid-vinyl siloxane complex etc. are mentioned. Among these platinum compounds, a complex of vinyl siloxane and a platinum compound, and a compound obtained by further modifying this with alcohol is preferable. In particular, chloroplatinic acid described in Japanese Patent Publication No. 33-9969, or a combination of vinyl siloxane and chloroplatinic acid. Complexes are preferred. The blending amount of the component (B) is 0.0001 to 10 parts by mass with respect to 100 parts by mass of the component (A). It becomes uneconomical. Preferably it is 0.005-1 mass part.

In addition, since this (A) component and (B) component will advance the crosslinking reaction by dehydrogenation simultaneously with mixing, it is desirable to add the control agent which suppresses reaction. Examples of the reaction control agent include acetylene-based alcohols and acetylene-based compounds described in Japanese Patent Publication No. 44-31476 and Japanese Patent Publication No. 1-1786.
The compounding quantity of this reaction control agent is 0.01-10 mass parts with respect to 100 mass parts of (A) component, and it is especially preferable that it is 0.05-3 mass parts. If the amount is less than 0.01 parts by mass, the effect of blending the reaction control agent may not be sufficiently obtained. If the amount is more than 10 parts by mass, the crosslinking curing reaction may be too slow.

  The method for producing an electric resistance stone is to heat treatment at 50 to 250 ° C. in order to form a crosslinked film on the surface after the above composition (treatment liquid) is directly or diluted with a solvent or applied or added to the stone as an emulsion. To do. Although there is no restriction | limiting in particular in the solvent which can be used in this case, What is necessary is just a thing in which Si-H bond containing organopolysiloxane melt | dissolves. Aromatic hydrocarbons (toluene, xylene), aliphatic hydrocarbons (petroleum ether, mineral spirit, kerosene, etc.), isopropyl alcohol and the like are exemplified. The emulsifier for emulsification is not particularly limited, and nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like can be used. If the treatment temperature is less than 50 ° C., the reaction takes too much time, which is impractical. If the treatment temperature is higher than 250 ° C., the silicone may be decomposed, so it is necessary to be 50 to 250 ° C. Under the present circumstances, the processing amount of the said composition (processing liquid) has preferable 0.1-20 mass% with respect to a stone material. If the treatment amount is less than 0.1% by mass, the wear resistance is poor, and if it exceeds 20% by mass, no further wear resistance effect can be obtained, which may be uneconomical. In addition, although processing time is selected suitably, it is preferable to set it as 1 to 8 hours, especially 3 to 5 hours.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an electric resistance stone material according to Example 1 of the present invention. As shown in FIG. 1, natural stone 2 having a particle diameter of 5 to 40 mm is dried on the electric resistance stone material 1, and the dried natural stone 2 A cured coating 3 composed of an organopolysiloxane and a platinum catalyst is formed on the surface of the surface, and the cured coating imparts water repellency and non-water retention to the natural stone 2.

[Example 1]
The manufacturing apparatus 11 for the electric resistance stone 1 and the manufacturing method using the same will be described. As shown in FIGS. 2 and 3, the manufacturing apparatus 11 includes a mixing device 12 that is fixedly provided. Is provided with a rotary drum 13 provided obliquely so as to be rotatable, and a rotary drive means 14 for rotationally driving the rotary drum 13. The rotary drive means 14 is rotated by the engine of the mixing device 12 as power. A hydraulic motor or the like is used. An inlet 13A for introducing the natural stone 2 is provided on the upper side in the longitudinal direction of the rotary drum 13.

  A base 15 is provided behind the mixing device 12, and heating means 16 for heating the natural stone 2 in the rotary drum 13 is provided on the base 15. The heating means 16 connects a heater 17 using kerosene as a fuel, a blower 18 for blowing air heated by a flame of the heater 17 into the rotary drum 13, and the blower 18 and the rotary drum 13. And an air duct 19 serving as an air passage.

  On the base 15, spraying means 21 is provided for spraying a mixed liquid containing organopolysiloxane and a platinum catalyst onto the natural stone 2 in the rotary drum 13. The spray means 21 includes a drug tank 22 for storing a mixed liquid containing an organopolysiloxane and a platinum catalyst, and a drug conduit 23 serving as a drug path provided between the drug tank 22 and the rotary drum 13. The drug pump 24 provided on the drug tank 22 side of the drug pipe line 23, the pressure metering tank 25 provided on the rotary drum 13 side of the drug pipe line 23, and the drug pipe line 23. A plurality of nozzles 26 for spraying a mixed liquid containing an organopolysiloxane of natural stone 2 and a platinum catalyst in the rotary drum 13 in a mist, and a compressor 27 serving as a power source for the drug pump 24; The nozzles 26 are arranged side by side in the rotation axis direction of the rotary drum 13.

  And the terminal end side of the said air duct 19 and the chemical | medical agent duct 23 is inserted in the insertion port 13A, reaches the inside of the rotary drum 13, and is supported by the base 15 in a cantilevered manner on the rotation center side. The rotating drum 13 is disposed so as not to obstruct the rotation.

  Furthermore, a control means 31 for controlling the driving of the manufacturing apparatus 11 is provided. As the control means 31, a metering, temperature control panel or the like is used. Further, a temperature sensor 20 for measuring the temperature in the rotary drum 13 is provided, and the temperature sensor 20 is provided in the air duct 19 or the drug pipe 23 in the rotary drum 13, and the temperature sensor 20 The measured temperature data is output to the control means 31, and the heating means 16 is controlled so that the inside of the rotary drum 13 has a predetermined temperature. Specifically, the heating power of the jet heater 17 and the air blowing of the blower 18 are controlled. To do. Further, the pressure data and the metering data of the mixed liquid containing the organopolysiloxane and the platinum catalyst measured in the pressure metering tank 25 are output to the control unit 31, and the control unit 31 sends the organopolysiloxane to the nozzle 26. The spraying means 21 is controlled so as to adjust the pressure of the mixed liquid containing siloxane and platinum catalyst and to adjust the amount of the mixed liquid containing organopolysiloxane and platinum catalyst sprayed into the rotary drum 13.

で示されるＳｉ−Ｈ結合含有オルガノポリシロキサン１０ｋｇとエチニルシクロヘキサノールの１０質量％トルエン溶液１００ｇを混合し、更に塩化白金酸−ビニルシロキサン錯体の０．５質量％トルエン溶液５０ｇを添加したものを処理液とした。 Next, an example of a method for manufacturing the electric resistance stone material 1 using the manufacturing apparatus 11 will be described.
For 1 ton of natural stone 2, the following formula

10 kg of Si-H bond-containing organopolysiloxane shown in the above and 100 g of a 10% by mass toluene solution of ethynylcyclohexanol were mixed, and 50 g of a 0.5% by mass toluene solution of a chloroplatinic acid-vinylsiloxane complex was further treated. Liquid.

  In the experiment, about 4 to 5 tons of natural stone 2 was put into the rotating drum 13 at a time. Therefore, the component ratio of the organopolysiloxane treatment liquid was 4 to 5 times the above value. The natural stone 2 was dried at the plant factory and charged into the rotating drum 13 and subjected to heat treatment at about 120 ° C. for about 4 to 5 hours. In this heat treatment step, the rotating drum 13 was continuously rotated. . About 2 hours of the first step of the heat treatment, the natural stone 2 in the rotary drum 13 is heated and dried by the heating means 16 without spraying the organopolysiloxane treatment liquid, and the water content is set to about 0% by mass. . Subsequently, for about 2 to 3 hours of the second step of the heat treatment, the natural stone 2 is heated so that the surface of the natural stone 2 becomes 100 to 120 ° C., and is about 30 to 60 minutes from the beginning of the second step. The organopolysiloxane treatment liquid was sprayed onto the rotating natural stone 2 from a plurality of nozzles 26, and the organopolysiloxane treatment liquid was baked on the surface of the natural stone 2 to form a cured coating 3 made of organopolysiloxane and a platinum catalyst. Following the second step of the heat treatment, a cooling step was performed. In this cooling step, heating was stopped by the heating means 16 and natural cooling was performed in about 1 hour.

  It is also possible to immerse the natural stone 2 in the organopolysiloxane treatment liquid, and thereafter bake it, but spray the organopolysiloxane treatment liquid onto the natural stone 2 in the rotating rotary drum 13. Therefore, the organopolysiloxane treatment liquid can be spread over the surface of the natural stone 2 with uniform and uniform quality, and the cured coating 3 made of the stable organopolysiloxane and platinum catalyst can be formed. The time excluding the time for spraying the organopolysiloxane treatment liquid in the second step of the heat treatment is preferably 1 to 2.5 hours, and if it is less than 1 hour, the treatment of the natural stone 2 of 1 ton or more is performed. Then, there is a possibility that a part where baking is insufficient is generated. On the other hand, if it exceeds 2.5 hours, there is no change even if it is performed more than this, and the manufacturing cost only increases. It was.

  And even if it is natural stone 2 heat-dried at the plant, there is a possibility that some moisture may be absorbed during the charging operation. Therefore, before spraying the organopolysiloxane treatment liquid as described above, natural stone 2 may be absorbed. By heating and drying 2, a cured coating 3 made of organopolysiloxane and a platinum catalyst can be formed on the surface of natural stone 2 having a moisture content of approximately 0% by mass.

  In the manufacturing method described above, the electric resistance stone material 1 obtained by spraying the organopolysiloxane treatment liquid for about 45 minutes from the beginning of the second step for the second step of the heat treatment for 2 hours was used as an experimental product. .

[Comparative Example 1]
Example 1 except that 50 g of a 0.5 mass% toluene solution of the chloroplatinic acid-vinylsiloxane complex of Example 1 and 100 g of a 10 mass% toluene solution of ethynylcyclohexanol were changed to 1 kg of a 50 mass% toluene solution of dioctyltin dilaurate. The electric resistance stone material 2 obtained in the same manner as described above was used as a comparative product.

  Here, the resistivity of the experimental product and the comparative product was measured. The resistivity (resistance value) was measured using the principle of volume specific concentration. First, the measurement principle will be described. As shown in FIG. 5, the measuring device has copper electrode plates 52, 52 arranged on both sides of an acrylic water tank 51, and commercial power is applied between these electrodes 52, 52, The resistance value was measured by the circuit current and the voltage across the electrode plates 52 and 52. This resistance R is expressed by the following (formula 1). The electrode plate 52 has a width × height of 100 mm × 100 mm.

R = ρL / A (Formula 1)
Where ρ: resistivity of the water tank catalyst
L: Length of water tank
A: Area of electrode plate

When the dimensions of the measuring apparatus shown in FIG. 5 are substituted into (Equation 1), the resistivity R becomes (Equation 2) below.
ρ = RA / L = 0.05 × R (Formula 2)
If the medium is a fluid or clay, the resistivity can be easily estimated by placing the medium in a water tank and measuring the resistance. However, in the case of an experimental product or a comparative product, there is a gap and direct measurement is not possible. Is possible.

Therefore, the amount of the medium put in the water tank is converted by the volume ratio concentration. The definition of the volume specific concentration γ is based on the following (Formula 3).
γ = Vs / Vo (Formula 3)
Where Vs: volume of the medium
Vo: Volume of water tank Since the volume ratio concentration of natural stone, which is a medium, does not become 100%, the resistivity when it was regarded as 100% was measured by extrapolation.

In order to confirm the usefulness of the measurement method based on the above-described measurement principle, an experiment was conducted using sand as a medium.
A commercial power supply (10 V) was added to the measuring apparatus shown in FIG. 5, and the water tank 51 was filled with tap water and sand was added. At this time, the volume of the water overflowing from the tap water was measured, thereby obtaining the volume of the sand, and by measuring the current together to obtain the resistance, the resistivity was obtained by the inverse formula of the above (Equation 2). The result is shown in FIG. Here, when the water tank 51 was filled with dry sand, that is, the resistivity having a volume specific concentration γ of 100% was measured, the result was 7,000 Ω · m.

From the experimental results shown in FIG. 6, data analysis by exponential regression was performed. When performing the analysis, the relationship between the resistivity y of the sand and the volume specific concentration x was assumed as shown in the following (formula 4).
y = ae ^bx + c (Formula 4)
As a result of analysis, the following constants were obtained.
a = 4.36 × 10 ⁻³ , b = 0.14, c = 58, e≈2.7
When the volume ratio concentration x = 0, y = c = 58 and the water resistivity of the water tank 51 is obtained. Further, when the volume specific concentration x = 100, y = 7,000, which is the resistivity of sand.

  In the case of the experimental product and the comparative product, since a gap is generated, the volume ratio concentration is about 60%. Therefore, the constant a of the exponential regression curve was estimated with reference to the formula for sand. Here, b and c in (Expression 4) are constant.

  First, when a was obtained based on the resistivity 111 Ω · m when the volume specific concentration was 60% in the case of an experimental product, a = 0.010 was obtained. Similarly, when a was obtained based on the resistivity 111 Ω · m when the volume ratio concentration was 60% in the case of the comparative product, it was a = 0.010. From these, the constants of the formulas of the experimental product and the comparative product were obtained and are shown in Table 1 below.

In the case of the experimental product and the comparative product, the volume specific concentration is not 100%. Therefore, the resistivity R was estimated by using the empirical formula of (Formula 4) and extrapolating the volume ratio concentration to 100%.
In (Formula 4), when x = 100 and the constants shown in Table 1 were substituted, the resistivity was 24,000 Ω · m for both the experimental product and the comparative product. The resistivity showed a value of approximately ± 5% in a plurality of experiments.
FIG. 7 is a graph showing the moisture content of the experimental product and the comparative product, and FIG. 8 is a time chart illustrating the manufacturing process.

  Next, for the purpose of evaluating the wear resistance of the electric resistance stone material, a half amount of the experimental product is put into a cylindrical container having a diameter of 15 cm and a height of 30 cm, and when the container is rolled and rotated 20 times, I took it out. Similarly, a comparative product after the wear test was also prepared.

  Using the experimental product and the comparative product after this wear test, the water tank 51 of the measuring apparatus shown in FIG. 5 was filled with tap water, and the change with time of the resistivity was measured. When the test product after the wear test and the comparative product after the wear test were exposed to tap water, the comparative product after the wear test contained water and tended to decrease in resistivity. The water repellent property of the cured coating 3 composed of organopolysiloxane and platinum catalyst was maintained, and the resistance was constant without containing water.

  In the comparative product, the initial resistivity was 24,000 Ω · m, but the resistivity decreased by about 15% by containing moisture. On the other hand, the experimental product had an initial resistivity of 24,000 Ω · m and water repellency.

  Next, an example of a method of using the electric resistance stone material 1 will be described. As shown in FIG. 4, a grass protection sheet 32 is laid on an electrical facility 30 such as electric power, communication, railway, and the surrounding ground surface 31. The electric resistance stone material 1 is laid in layers on the weedproof sheet 32. As the weedproof sheet 32, a sheet of polyester nonwoven fabric or the like having air permeability and water permeability is used, and the thickness of the layer of the electric resistance stone material 1 is about 30 to 50 mm, and the usage conditions depending on the generated voltage or the like Set by. The ground surface 31 is made of embankment or soil, and has water permeability. In addition, in FIG. 4, the substation and the steel tower of a power transmission line are illustrated as the electrical related facility 30, and the end portions of the weedproof sheets 32, 32 are overlapped and overlapped as shown in FIG. The mating portion 32A is formed, and the end portions are bonded together with an adhesive or the like.

  By providing a layer of electric resistance stone material 1 that has a high resistivity and does not decrease in resistivity, even if an abnormal voltage is generated by the facility and current leaks to the ground surface, the resistance of the layer of electric resistance stone material 1 , Stride voltage and contact voltage can be reduced.

  In this example, the cured coating 3 made of organopolysiloxane and platinum catalyst having excellent wear resistance was formed on the surface of the dried natural stone 2 having a particle diameter of 5 to 40 mm, so that water repellency and non-water retention are obtained. Therefore, even when exposed to water, the dried natural stone 2 does not contain water, repels water, and maintains high electrical resistance over a long period of time. Thus, the stride voltage and the contact voltage can be reduced by laying around the facility.

  In this example, since the water repellent layer is a cured coating 3 made of an organopolysiloxane and a platinum catalyst having excellent wear resistance, the electric resistance stone material 1 has high water repellency and non-water retention, and Resistance performance can be maintained over a long period of time.

  Furthermore, in this embodiment, natural stone 2 having a particle size of 5 to 40 mm is dried by heating, and the dried natural stone 2 is sprayed with an organopolysiloxane treatment liquid, heated and baked to form an organopolysiloxane on the surface of natural stone 2. Since the cured coating 3 made of siloxane and a platinum catalyst is formed, the electric resistance stone material 1 having high water repellency and non-water retention can be produced by spraying an organopolysiloxane treatment liquid and heating and baking it. .

  In this way, in this embodiment, the rotating stone 13 that is used in the method of manufacturing the electric resistance stone material 1, is loaded with the natural stone 2 and is rotated by the rotation driving means 14, and the natural stone 2 in the rotating drum 13 is used. Since the heating means 16 for heating and the spray means 21 for spraying the organopolysiloxane treatment liquid onto the natural stone 2 in the rotary drum 13 are provided, the rotary drum 13 charged with the natural stone 2 is rotated by the rotation driving means 14. The organopolysiloxane treatment liquid is sprayed on the heated natural stone 2 by the spraying means 21 and further heated by the heating means 21 to be baked with the organopolysiloxane treatment liquid. A cured coating 3 composed of polysiloxane and a platinum catalyst can be easily formed on the surface of natural stone 2.

In addition, as an effect on the embodiment, the electric resistance stone material 1 maintains a resistivity of 24,000 Ω · m (22,800 to 25,200 Ω · m). In contrast, it is an effective means. In addition, the weedproof sheet 32 is laid and the electric resistance stone 1 is non-water-retaining, so that weeds can be prevented from breeding. Further, since the plurality of nozzles 26 are arranged side by side in the rotation axis direction of the rotary drum 13, it is possible to spray the natural stone 2 in the rotary drum 13 uniformly.
In addition, this invention is not limited to the said Example, A various deformation | transformation implementation is possible.

DESCRIPTION OF SYMBOLS 1 Electric resistance stone material 2 Natural stone 3 Hardened coating 11 which consists of organopolysiloxane and a platinum catalyst Manufacturing apparatus 13 Rotating drum 14 Rotation drive means 16 Heating means 21 Injection means 30 Electrical facilities

Claims (5)

(A) Organopolysiloxane containing at least three Si-H bonds in one molecule
100 parts by mass,
(B) Platinum catalyst An electric resistance stone material obtained by adhering a composition containing 0.0001 to 10 parts by mass to the surface of dry natural stone having a particle size of 5 to 50 mm and heat-treating it.   The electric resistance stone material according to claim 1, wherein the composition further comprises 0.01 to 10 parts by mass of (C) a reaction control agent with respect to 100 parts by mass of component (A). (A) Organopolysiloxane containing at least three Si-H bonds in one molecule
100 parts by mass,
(B) Platinum catalyst An electrical resistance characterized by adhering a composition containing 0.0001 to 10 parts by mass to the surface of dry natural stone having a particle size of 5 to 50 mm and heat-treating at 50 to 250 ° C. Stone manufacturing method.   The method for producing an electric resistance stone according to claim 3, wherein the composition further comprises 0.01 to 10 parts by mass of (C) a reaction control agent with respect to 100 parts by mass of component (A).   A natural stone having a particle size of 5 to 50 mm is put into a rotating drum rotated by a rotation driving means, and the natural stone is dried and heated by a heating means attached to the rotating drum, and by a spraying means attached to the rotating drum. The method for producing an electric resistance stone material according to claim 3 or 4, wherein the natural stone is treated by spraying the composition according to claim 3 or 4.

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