JP3289041B2 - Exothermic coarse particles and exothermic structures using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to exothermic coarse particles using coarse particles such as gravel. The present invention also relates to a heat-generating structure in which the layer of the heat-generating coarse particles is provided on the ground.

[0002]

2. Description of the Related Art An exothermic composition having the property of generating heat upon energization can be used for various applications as a sheet heating element.

For example, paints, rugs, road signs, curved mirrors, automobiles, automobile seats, ski lifts, roofs, roads, parking lots, flooring, interior materials, indoor equipment, pipes, drafting boards, refrigerators, toilet seats, It can be used for helmets, copiers, containers, thermistors, thermal heads, and various other applications requiring heating, snow melting, freeze prevention, heating, preheating, warming, drying, anti-fog, defrosting, etc.

[0004] Generally, the exothermic composition comprises conductive particles and a binder material. As the conductive particles, various materials in the form of particles or fibers are used, and among them, typical materials using graphite (graphite) as the conductive particles are listed below.

Japanese Patent Laid-Open Publication No. 56-53781 As conductive particles, graphite, carbon black,
A planar heating element using cuprous oxide, lead dioxide, Ag, Au, Ni, Pt, ruthenium oxide or the like. JP-A-59-98490 A planar heating element using a two-component conductive agent of graphite and carbon black and using a hot melt adhesive. JP-A-60-135950 A mask in which a graphite paste is applied to a support. JP-A-62-131492 A flexible surface heater in which a metal powder, carbon black, or the like is mixed during the production of a graphite paste. -JP-A-62-199663 A conductive coating composition using carbon black and / or graphite. -JP-A-63-110590 A planar heating element using both conductive carbon black and graphite. JP-A-63-138885 A surface heating element resistance paste using graphite, carbon black, metal or the like. Patent Document 1: JP-A-1-107488 A conductive heating element using spherical carbon (mesocarbon microbeads) and spherical graphite particles. JP-A-1-108276 A conductive heat-generating paint using spherical carbon (mesocarbon microbeads) and spherical graphite particles. JP-A-3-47788 JP-A-3-47788 In the surface of the composition of the aromatic polyamide and the conductive carbon,
A resist composition film in which a cured coating of a paint containing a thermosetting resin and natural graphite is formed. A non-metallic heating element in which a carbon or graphite heating element is covered with a specific oxide pipe. A conductive heating element using a metal oxide and spherical carbon (spherical graphite) in combination. JP-A-62-180043 An exothermic paint containing carbon powder and metal powder.

On the other hand, as the binder resin, in the literature (publication) cited above, silicone resin, hot melt adhesive, polyvinyl alcohol, fluoro rubber,
Urethane rubber, vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-vinyl acetate resin, acrylic resin, polyethylene resin, cellulose resin, polyurethane, vinyl resin, polytetrafluoroethylene, polyetheretherketone, polyester, epoxy resin Polyamide, polyimide, polyphenylene sulfide, silicone, polyfluorocarbon resin, polytitanocarbosilane resin and the like are used.

[0007]

Among the applications of the exothermic composition, for applications that occupy a large area, such as airfield runways, roads, parking lots, stadiums, etc., the ordinary exothermic composition bears the cost. Is extremely large, which hinders practical use.

[0008] Even if the cost is not taken into consideration, the general exothermic composition has a problem in terms of heat generation performance, such as insufficient heat generation efficiency and local heating as compared with the amount of electricity.

Under such a background, the present invention is suitable for use in the prevention of freezing and snow in airfield runways, roads, parking lots, etc., and is economically advantageous and has excellent heat generation performance. It is an object of the present invention to provide grains and a structure using the exothermic coarse grains.

[0010]

The exothermic coarse particles of the present invention are:
A layer of an exothermic composition (AB) comprising conductive particles (A) and a binder substance (B) is formed on the surface of coarse particles (C) such as gravel.

In the heat-generating structure of the present invention, an insulating layer (2) is provided on the ground (1), and a layer (3) of the above-described heat-generating coarse particles is provided on the insulating layer (2). In addition, an electrode (4) is provided, and an insulating layer (5) is further provided on the layer (3) of the heat-producing coarse particles. In this case, a surface layer (6) is often further provided on the insulating layer (5).

Hereinafter, the present invention will be described in detail.

<Coarse Grain (C)> As the coarse grain (C), gravel, crushed stone, concrete pieces, glass pieces, tile pieces, brick pieces, plastic pieces, wood pieces and the like are used.

<Conductive Particles (A)> The conductive particles (A) include scale-like graphite particles (a ₁ ) as an essential component,
(a ₂ ), metal particles (a ₃ ), metal salt (a ₄ ) or metal oxide (a ₅ )
Is used as an optional component.

The scaly graphite particles (a ₁ ) have a major axis of 3
Those having a diameter of 00 μm or less, preferably 5 to 50 μm, and a minor axis of 200 μm or less, preferably 3 to 30 μm are suitably used. Graphite particles are in the form of flakes, spheres, other particles such as earth, but the scale-like graphite particles are most suitable for the purpose of the present invention, so even when using other than the scale-like graphite particles, the scale-like graphite particles Should be used together.

As the conductive glue carbon (a ₂ ), conductive glue carbon is used, and Ketjen black is particularly important. The proper amount of conductive glue carbon (a ₂ ) is
Maximizes the heat generation performance of the flake graphite particles (a ₁ ).

As the metal particles (a ₃ ), copper, nickel, chromium, cobalt, silver, iron, and the like are used, and nickel, chromium, or cobalt is highly practical in consideration of the cost, the property of being hardly oxidized, and the like. The shape of the metal particles (a ₃ ) is particularly preferably spherical. The particle size of the metal particles (a ₃ ) is 3
00 μm or less, preferably 100 μm or less, especially 0.5 to
It is desirable that the thickness be 15 μm.

Examples of the metal salt (a ₄ ) include halogen compounds such as iron, copper, tin, sodium, nickel, chromium, and cobalt (for example, tin chloride and nickel chloride), potassium,
Titanate compounds such as aluminum and barium are used.

As the metal oxide (a ₅ ), iron, nickel,
Chromium, cobalt, copper and other metal oxides are used,
Particularly, nickel oxide is important. The particle size of the metal oxide (a ₅ ) is desirably 300 μm or less, preferably 100 μm or less, particularly preferably 2 to 15 μm.

<Binder substance (B)> Binder substance
As (B), acrylic resin, polyester resin,
Organics including alkyd resins, urethane resins, epoxy resins, vinyl resins, polyolefin resins, polyamide resins, polyimide resins, silicone resins, polytitanocarbosilane resins, fluorine resins, and cellulose resins Inorganic binders such as cement binders such as lime cement, silicate cement, and magnesium cement, quick gypsum, calcined gypsum, and gypsum cement are used.

<Exothermic Coarse Grains> The exothermic coarse particles of the present invention are composed of an exothermic composition (AB) composed of conductive particles (A) and a binder substance (B) on the surface of coarse particles (C) such as gravel. ) Is formed. Such exothermic coarse particles include coarse particles such as gravel (C), conductive particles (A) and binder material (B),
It can be obtained by mixing with a diluent or an additive as required and by an appropriate means.

Conductive particles (A) in exothermic composition (AB)
And the binder material (B) are in a weight ratio of 93:
It is desirable to set 7 to 55:45. Conductive particles
Insufficient (A) causes insufficient heat generation performance, and heat is not generated unless a high voltage is applied. Hand binder material
Insufficiency of (B) causes insufficient strength of the coating film or molded product. A particularly preferred range is from 85:15 to 60:40.

Scale-like graphite particles (a ₁ ) in the conductive particles (A)
It is particularly desirable that the ratio of the flake graphite particles (a ₁ ) to the binder substance (B) be 20 to 85% by weight. If the ratio is outside these ranges, the desired heat generation performance cannot be obtained.

The conductive granular carbon (a) together with the scale-like graphite particles (a ₁ )
₂ ), spherical metal particles (a ₃ ), metal salts (a ₄ ) or metal oxides (a
_{When 5} ) is used in combination, the weight ratio of the scale-like graphite particles (a ₁ ): conductive aggregated carbon (a ₂ ) is 99: 1 to 60:40, and the scale-like graphite particles (a ₁ ) :( spherical metal particles (a _3), the weight ratio of the metal salt (a ₄₎ or metal oxide (a ₅₎₎ is 80: 20 to 20: it is desirable that the 80.

The exothermic composition (AB) is coated on the surface of the coarse particles (C) by 5
It is desirable to form the layer with a thickness of about 0 to 200 μm, but it is not necessarily limited to this range.

When compounding each component, besides, diluents (solvents, etc.), anti-settling agents (polymers, bentonite, fine powdered silica, etc.), dispersants (surfactants, etc.), stabilizers (antioxidants, etc.) ), A leveling agent, a foaming agent, a filler, a coloring agent, a reinforcing fiber, a drying oil, a semidrying oil, a softening agent (such as ethylene glycol), and the like.

<Heat-generating structure> An insulating layer (2) on the ground (1)
The heat-generating coarse-grain layer (3) is provided from above the insulating layer (2), and the electrode (4) is further provided.The insulation is further formed on the heat-generating coarse-grain layer (3). By providing the layer (5), the exothermic structure of the present invention is obtained.

Examples of the ground (1) include a ground surface, a surface for placing crushed stones, and a surface for placing concrete. Insulation layer (2)
Examples thereof include a plastic sheet layer, a rubber sheet layer, and an organic or inorganic waterproof or insulating coating surface.

Exothermic coarse-grain layer (3) provided on insulating layer (2)
Is often about 20 to 100 mm.

The electrode (4) and the terminal are formed of a highly conductive material such as a metal foil, a metal stamped plate, a metal wire, and a silver paste. The electrode (4) is installed in a comb shape or the like in consideration of generating heat over a wide area. The energization may be AC or DC. The electrode (4) is provided on the lower surface side, the upper surface side, or in the middle of the layer (3) of the exothermic coarse particles.

Examples of the insulating layer (5) include a plastic sheet layer, a rubber sheet layer, an organic or inorganic waterproof or insulating coating surface, and the like.

From the insulating layer (5), a surface layer (6) such as a concrete casting surface, a concrete plate installation surface, a bituminous construction surface, earth and sand, etc. can be formed as appropriate.

[0033]

FIG. 1 is an explanatory view schematically showing the exothermic coarse particles of the present invention. For each exothermic coarse particle, the surface of the coarse particle (C) such as gravel has conductive particles (A) and binder material.
A layer of the exothermic composition (AB) consisting of (B) is formed,
The exothermic composition (A
The layers in B) can come into contact with each other.

The exothermic coarse particles can be formed on the ground (1) via an insulating layer (2) at the site to form a layer of exothermic coarse particles (3). At the stage of forming the layer (3), the coarse particles (C) such as gravel serve as a structural material and can cover a wide area with a minimum amount of the exothermic composition (AB).

The heat-generating coarse-grain layer (3) needs to have a thickness such that it is not interrupted even when heavy objects pass through, because the layer is formed on the ground (1) via the insulating layer (2). Since the layer of the exothermic composition (AB) itself is thin, in terms of electric conductivity, the heat generation and heat storage effects are larger than when the exothermic paint is simply applied to the same thickness, and good results are obtained.

As described above, in the heat-generating coarse particles of the present invention, the heat-generating composition (AB) composed of the coarse particles (C) such as gravel and the conductive particles (A) and the binder substance (B) is used. The layers interact skillfully to exert a synergistic effect.

Moreover, when the scale-like graphite particles (a ₁ ) are used as the conductive particles (A), excellent heat generation performance is exhibited due to their excellent conductivity and their unique particle shape.

The conductive aggregated carbon (a ₂ ) can exhibit the conductive performance of the scale-like graphite particles (a ₁ ) to the maximum by mixing an appropriate amount thereof. In particular, it is effective in adjusting the electric resistance value and developing a high temperature at a low voltage.

The metal particles (a ₃ ) complement the heat generation performance of the scale-like graphite particles (a ₁ ) and contribute to exhibiting more stable heat generation.

The presence of the metal salt (a ₄ ) and the metal oxide (a ₅ ) is advantageous in enhancing the ability to control the exothermic temperature.

[0041]

The present invention will be further described with reference to the following examples. Hereinafter, “parts” and “%” are expressed on a weight basis.

Example 1 FIG. 2 is an explanatory view schematically showing one example of the heat-generating structure of the present invention.

<Exothermic Coarse Particles> The conductive particles (A) were prepared by uniformly mixing the following particles. 40 parts of scale-like graphite particles 30 μm in major axis and 8 μm in minor axis 5 parts of spherical Ketjen black particles 5 to 15 μm in diameter 45 parts of spherical nickel particles 0.5 to 5.0 μm in diameter 10 parts of 5.0μm spherical chromium particles

As the binder substance (B), a resin varnish having the following formulation was mixed uniformly.・ 11.3 parts of silicone resin varnish ・ 3.8 parts of melamine-modified alkyd resin varnish ・ 1.9 parts of epoxy resin varnish

To 100 parts of the conductive particles (A), 30 parts of the binder material (B) and 50 parts of a diluting solvent (25 parts of xylene, 20 parts of methyl isobutyl ketone, 5 parts of ethyl acetate)
Parts) and a small amount of an anti-settling agent, a stabilizer, and a thixotropic agent, and then uniformly mixed with 420 parts of gravel as an example of coarse particles (C), and dried by heating to obtain coarse particles (C )), Heat-generating coarse particles having a layer of a heat-generating composition (AB) composed of conductive particles (A) and a binder substance (B) formed on the surface thereof.

<Heat-generating structure> A 120 µm-thick polyester film as an example of an insulating layer (2) is laid on a concrete casting surface as an example of the ground (1), and the heat-generating material obtained above is laid thereon. The coarse particles were discharged while being mixed, and then pressed by a roller wheel to reduce and smooth the voids, thereby forming a layer (3) of heat-generating coarse particles having a thickness of about 60 mm.

Next, an electrode (4) made of an aluminum plate formed into a comb shape by punching on the layer (3) of the exothermic coarse particles.
(Distance between the electrodes is 200mm), and the insulating layer (5)
A rubber sheet with a thickness of about 5 mm is laid as an example, and concrete is further poured on the rubber sheet from a concrete mixer truck, and is hardened by standing, and a concrete layer with a thickness of about 100 mm is laid as an example of the surface layer (6). A layer was formed.

Thus, FIG. 2 having a layer structure of ground (1) / insulating layer (2) / heat-generating coarse-grained layer (3) / electrode (4) / insulating layer (5) / surface layer (6) The exothermic structure shown in (1) was obtained.

When a current was applied to the electrode (3) of the heat-generating structure from a 100-volt power supply, the surface temperature could be raised to about 5 ° C. in about 40 minutes at a temperature of −10 ° C. The amount of power required to maintain the temperature was only 250 watts per square meter.

The heat-generating structure is useful as an airfield runway, road (general road or highway), bridge, parking lot, stadium, or a heatable livestock floor having a function of preventing freezing or snow accumulation. is there.

Example 2 <Exothermic Coarse Grain> 27 parts of scale-like graphite particles having a major axis of 30 μm and a minor axis of 8 μm, 4 parts of spherical Ketjen black particles having a particle diameter of 5 to 15 μm, and a particle diameter of 0.5 to 5.0 μm 27 parts of spherical nickel particles, 14 parts of spherical chromium particles having a particle size of 0.5 to 5.0 μm, 21 parts of barium titanate particles having a particle size of 10 to 15 μm, 7 parts of nickel oxide particles having a particle size of 2 to 5 μm

After mixing 100 parts of the above-mentioned conductive particles (A) with 70 parts of a binder substance (B) composed of an acrylic emulsion having a solid content of 50%, 390 parts of gravel as an example of coarse particles (C) are added. Mix evenly, heat and dry, coarse particles (C)
Exothermic coarse particles having a layer of the exothermic composition (AB) comprising the conductive particles (A) and the binder substance (B) formed on the surface of were prepared.

<Heat-generating structure> A 120 µm-thick polyester film as an example of the insulating layer (2) is laid on the concrete casting surface as an example of the ground (1), and the heat-generating structure obtained above is laid thereon. The coarse particles were discharged while being mixed, and then pressed by a roller wheel to reduce and smooth the voids, thereby forming a layer (3) of heat-generating coarse particles having a thickness of about 60 mm.

Next, an electrode (4) made of an aluminum plate formed in a comb shape by punching on the layer (3) of the exothermic coarse particles.
(Distance between the electrodes is 200mm), and the insulating layer (5)
A polypropylene sheet with a thickness of about 1 mm is laid as an example, and concrete is further poured on it from a concrete mixer truck and cured by standing.
As an example of (6), a concrete casting layer having a thickness of about 50 mm was formed.

The exothermic structure thus obtained is
It is suitable for the same uses as in the first embodiment.

Example 3 A polypropylene sheet having a thickness of about 1 mm as an example of an insulating layer (2) was laid on the ground of a greenhouse as an example of the ground (1), and the exothermic coarse particles of Example 2 were mixed thereon. While discharging
Subsequently, the gap (3) having a thickness of about 30 mm was formed by reducing and smoothing the air gap while applying vibrations with a ground leveler rammer.

Next, an electrode (4) made of an aluminum plate formed into a comb shape by punching on the layer (3) of the exothermic coarse particles.
(Distance between the electrodes is 200mm), and the insulating layer (5)
A polypropylene sheet having a thickness of about 1 mm was laid as an example, and soil as an example of the surface layer (6) was further placed thereon to a thickness of about 300 mm. The exothermic structure thus obtained is useful as ground for a greenhouse.

[0058]

As described in the section of action, the exothermic coarse particles of the present invention are applied on the ground (1) via an insulating layer (2) on the ground at the site, thereby forming a layer (3) of the exothermic coarse particles. At the stage of forming the layer of exothermic coarse particles (3), coarse particles such as gravel (C) serve as a structural material and minimize the amount of exothermic composition (AB) Can cover a wide area. As described above, in addition to being excellent in terms of on-site workability and economic efficiency, the heat generation performance is also excellent, such as good heat generation efficiency and a high temperature rising rate as compared with the amount of electricity.

Therefore, the heat-generating structure of the present invention is most suitable for applications such as airfield runways, roads, parking lots, bridges, stadiums, etc., to prevent freezing and snowfall, to heat the floor of livestock stalls, and to use greenhouse greenery. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing exothermic coarse particles of the present invention.

FIG. 2 is an explanatory view schematically showing an example of a heat-generating structure of the present invention.

[Explanation of symbols]

 (A) ... conductive particles, (B) ... binder material, (AB) ... exothermic composition, (C) ... coarse particles, (1) ... ground, (2) ... insulating layer, (3) ... heat generation Coarse-grained layer, (4)… electrode, (5)… insulating layer, (6)… surface layer

Claims (4)

(57) [Claims] (1) conductive particles on the surface of coarse particles (C) such as gravel;
(A) and a heat-generating composition (A) comprising the binder substance (B).
Exothermic coarse particles formed by layer B). 2. The conductive particles (A) are composed of scale-like graphite particles (a ₁ ) as an essential component, and are formed of conductive granular carbon (a ₂ ), metal particles (a ₃ ), metal salt (a ₄ ) or metal. oxide (a ₅₎ the exothermic grit according to claim 1, wherein it is an optional component. 3. An insulating layer (2) is provided on the ground (1), and a layer (3) of the heat-generating coarse particles according to claim 1 is provided from above the insulating layer (2), and an electrode (4) is provided. A heat-generating structure which is installed and further provided with an insulating layer (5) on the heat-generating coarse-grain layer (3). 4. The heat-generating structure according to claim 3, further comprising a surface layer (6) provided on the insulating layer (5).