JPH06231868A - Heating coarse particle and heating structure using the particle - Google Patents

Abstract

PURPOSE:To provide a heating coarse particle suitable for use to prevent the freeze and snow coverage of an airport landing strip, a road, a parking lot or the like, giving an economical advantage and ensuring high heating performance. CONSTITUTION:The heating coarse particles are made of coarse-particles C such as gravel with the layer of a heating composite AB of a conductive particulate A and a binder material B formed on the surface thereof. The particulate A should preferably contain a flaky graphite particulate a1 as an essential component. Also, a heating structure has an insulation layer 2 on a subsoil 1 and a coarse particle layer 3 is laid on the insulation layer 2. Also, an electrode 4 is laid and another insulation layer 5 is laid on the layer 3. Furthermore, a surface layer 6 is ordinarily formed on the insulation layer 5.

Description

Detailed Description of the Invention

[0001]

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

[0002]

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

For example, paints, rugs, road signs, curve mirrors, automobiles, automobile seats, ski lifts, roofs, roads, parking lots, floor materials, interior materials, indoor equipment products, pipes, drawing boards, refrigerators, toilet seats, It can be used for helmets, copiers, containers, thermistors, thermal heads, as well as various applications where heating, snow melting, freeze prevention, heating, preheating, heat retention, drying, anti-fog, defrosting, etc. are required.

Generally, the exothermic composition comprises electrically conductive particles and a binder material. Although various materials in the form of particles or fibers are used as the conductive particles, typical ones of the documents in which graphite (graphite) is used as the conductive particles are listed below.

Japanese Patent Application Laid-Open 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 sheet heating element using a two-component conductive agent of graphite and carbon black and a hot melt adhesive. Japanese Patent Laid-Open No. 60-135950 A mask in which a graphite paste is applied to a support. JP-A-62-131492 A flexible surface heater in which metal powder, carbon black and the like are mixed at the time of producing the graphite paste. Japanese Patent Application Laid-Open No. 62-199663 A conductive coating composition using carbon black and / or graphite. Japanese Patent Application Laid-Open No. 63-110590 A planar heating element that uses conductive carbon black and graphite in combination. Japanese Patent Application Laid-Open No. 63-138685 A surface heating element resistance paste using graphite, carbon black, metal or the like. JP-A-1-107488 SUMMARY OF THE INVENTION Conductive heating element using spherical carbon (mesocarbon microbeads) and spherical graphite particles. Japanese Patent Application Laid-Open No. 1-108276 A conductive exothermic coating material using spherical carbon (mesocarbon microbeads) and spherical graphite particles. JP-A-3-47788 On the surface of the composition of aromatic polyamide and conductive carbon,
A resistive composition film having a cured coating film of a coating material containing a thermosetting resin and natural graphite. Japanese Patent Laid-Open No. 3-156875 A non-metallic heating element in which a carbon or graphite heating element is covered with a specific oxide pipe. Japanese Patent Application Laid-Open No. 3-195782 A conductive heating element in which a metal oxide and spherical carbon (spherical graphite) are used in combination. Japanese Utility Model Publication No. 62-180043 A heat-generating coating material 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, fluororubber,
Urethane rubber, vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-vinyl acetate resin, acrylic resin, polyethylene resin, cellulose resin, polyurethane, vinyl resin, polytetrafluoroethylene, polyether ether ketone, polyester, epoxy resin , Polyamide, polyimide, polyphenylene sulfide, silicone, polyfron resin, polytitanocarbosilane resin and the like are used.

[0007]

Among the applications of the heat-generating composition, for the use of a vast area such as an airfield runway, a road, a parking lot, and a stadium, the cost of the conventional heat-generating composition is low. Is extremely excessive, which hinders its commercialization.

Further, even if the cost is not taken into consideration, a general exothermic composition has a problem in exothermic performance such as insufficient exothermic efficiency or local heating as compared with the amount of energization.

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

[0010]

Means for Solving the Problems The heat-generating coarse particles of the present invention are
A layer of a heat-generating composition (AB) consisting of 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, the insulating layer (2) is provided on the ground (1), and the layer (3) of the above-mentioned heat-generating coarse particles is further provided on the insulating layer (2). In addition, an electrode (4) is installed, and an insulating layer (5) is further provided on the layer (3) of heat-generating coarse particles. In this case, a surface layer (6) is often provided on the insulating layer (5).

The present invention will be described in detail below.

<Coarse Grains (C)> As the coarse particles (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) are composed of scaly graphite particles (a ₁ ) as an essential component, and conductive graphite particles are used.
(a _2), metal particles (a _3), a metal salt (a ₄₎ or metal oxide (a ₅₎
Is used as an arbitrary 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 short diameter of 200 μm or less, preferably 3 to 30 μm are suitably used. There are other particle shapes such as scale-like, spherical, and earth-like graphite particles, but since scale-like graphite particles are most suitable for the purpose of the present invention, scale-like graphite particles are used even when other than scale-like graphite particles are used. Should be used together with.

As the conductive glue-like carbon (a ₂ ), a glue-like carbon having conductivity is used, and Ketjen black is particularly important. The proper amount of conductive glue carbon (a ₂ ) is
Maximize the heat generation performance of the scaly 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 cost and the property of being hard to be oxidized. 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 to set it to 15 μm.

Examples of the metal salt (a ₄ ) include halogen compounds such as iron, copper, zinc, sodium, nickel, chromium and cobalt (eg tin chloride or nickel chloride), potassium,
A titanate compound such as aluminum or barium is used.

The metal oxide (a ₅ ) includes iron, nickel,
Oxides of metals such as chromium, cobalt and copper are used,
Nickel oxide is particularly important. The particle size of the metal oxide (a ₅ ) is 300 μm or less, preferably 100 μm or less, and particularly preferably 2 to 15 μm.

<Binder substance (B)> Binder substance
(B), acrylic resin, polyester resin,
Organics such as alkyd resin, urethane resin, epoxy resin, vinyl resin, polyolefin resin, polyamide resin, polyimide resin, silicone resin, polytitanocarbosilane resin, fluorine resin, cellulose resin An inorganic binder such as a system binder and cement such as lime cement, silicate cement, and magnesium cement, raw gypsum, calcined gypsum, and gypsum cement is used.

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

Conductive particles (A) in the exothermic composition (AB)
The mixing ratio of the binder substance (B) and the binder substance (B) is 93:
It is desirable to set it to 7 to 55:45. Conductive particles
If the amount of (A) is too small, the heating performance will be insufficient, and heat will not be generated unless a high voltage is applied. Meanwhile binder material
If the amount of (B) is too small, the strength of the coating film or the molded product will be insufficient. A particularly preferred range is 85:15 to 60:40.

Scale-like graphite particles (a ₁ ) in the conductive particles (A)
It is particularly preferable that the ratio of the above is 20% by weight or more and the ratio of the scaly graphite particles (a ₁ ) to the binder substance (B) is 20 to 85% by weight. This is because if it deviates from these ranges, the desired heat generation performance cannot be obtained.

With the scaly graphite particles (a ₁ ), the conductive glue-like carbon (a 1
₂ ), spherical metal particles (a ₃ ), metal salt (a ₄ ), or metal oxide (a
_{When 5} ) is used in combination, the scaly graphite particles (a ₁ ): conductive glue-like carbon (a ₂ ) are in a weight ratio of 99: 1 to 60:40, and the scaly 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) was added to the surface of the coarse particles (C) by 5
It is desirable to form it to a thickness of about 0 to 200 μm, but it is not necessarily limited to this range.

In addition to the components, diluents (solvents, etc.), anti-settling agents (polymers, bentonite, fine powder 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 semi-drying oil, a softening agent (ethylene glycol, etc.) and the like can be added.

<Exothermic structure> Insulating layer (2) on the ground (1)
And the electrode (4) on top of the insulating layer (2) and the above-mentioned 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 the ground surface, the surface for placing crushed stone, the surface for placing concrete, and the like. Insulation layer (2)
Examples thereof include a plastics sheet layer, a rubber sheet layer, and an organic or inorganic waterproof or insulating coating surface.

Layer (3) of heat-generating coarse particles provided on the insulating layer (2)
The layer thickness is usually about 20 to 100 mm.

The electrodes (4) and terminals are formed of a metal foil, a metal punching plate, a metal wire, a silver paste or the like having high conductivity. The electrode (4) is installed in a comb shape or the like in consideration of heat generation in a wide area. The energization may be alternating current or direct current. This electrode (4) is provided on the lower surface side, the upper surface side or the middle of the layer (3) of heat-generating coarse particles.

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

On the insulating layer (5), a surface layer (6) such as a concrete placing surface, a concrete plate mounting surface, a bituminous construction surface, or earth and sand can be appropriately formed.

[0033]

FUNCTION FIG. 1 is an explanatory view schematically showing the heat-generating coarse particles of the present invention. In the case of individual exothermic coarse particles, the conductive particles (A) and the binder substance are placed on the surface of the coarse particles (C) such as gravel.
A layer of the exothermic composition (AB) consisting of (B) is formed,
Exothermic composition (A
The layers of B) can contact each other.

This exothermic coarse particle can be made into a layer (3) of exothermic coarse particles by constructing on the ground (1) on the ground through the insulating layer (2). 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-grained layer (3) needs to have such a thickness that it will not be interrupted even when a heavy load passes because of the construction on the ground (1) via the insulating layer (2). Since the layer of the exothermic composition (AB) itself is thin, in terms of electric transmission, the heat and heat storage effects are greater than simply applying the exothermic coating 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) comprising the coarse particles (C) such as gravel and the conductive particles (A) and the binder substance (B) is used. The layers skillfully influence each other to exert a synergistic effect.

Moreover, when the scaly 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 glue-like carbon (a ₂ ) maximizes the conductive performance of the scaly graphite particles (a ₁ ) by blending it in an appropriate amount. 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 exothermic performance of the scaly graphite particles (a ₁ ) and contribute to exhibiting more stable exothermic properties.

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

[0041]

EXAMPLES The present invention will be further described with reference to examples. Hereinafter, "part" and "%" are expressed on a weight basis.

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

<Exothermic Coarse Grains> The conductive particles (A) were prepared by uniformly mixing the following particles. 40 parts of scaly graphite particles having a long diameter of 30 μm and a short diameter of 8 μm, 5 parts of spherical Ketjen black particles having a particle diameter of 5 to 15 μm, 45 parts of spherical nickel particles having a particle diameter of 0.5 to 5.0 μm, and a particle diameter of 0.5 to 5.0 μm spherical chrome particles 10 parts

As the binder substance (B), a resin varnish having the following formulation was uniformly mixed and prepared.・ Silicone resin varnish 11.3 parts ・ Melamine modified alkyd resin varnish 3.8 parts ・ Epoxy resin varnish 1.9 parts

100 parts of the above-mentioned conductive particles (A), 30 parts of the above-mentioned binder substance (B), 50 parts of a diluting solvent (25 parts of xylene, 20 parts of methyl isobutyl ketone, 5 parts of ethyl acetate).
Part), 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), followed by heating and drying to obtain coarse particles (C Exothermic coarse particles in which a layer of the exothermic composition (AB) composed of the conductive particles (A) and the binder substance (B) was formed on the surface of (4) were produced.

<Exothermic structure> A polyester film having a thickness of 120 μm as an example of the insulating layer (2) is laid on the concrete placing surface as an example of the ground (1), and the exothermic property obtained above is placed on it. The coarse particles were discharged while being mixed, and subsequently pressed by a roller wheel to reduce and smooth the voids, thereby forming a layer (3) of exothermic coarse particles having a thickness of about 60 mm.

Then, an electrode (4) made of an aluminum plate formed in a comb shape by punching is formed on the layer (3) of the heat-generating coarse particles.
(Distance between electrodes is 200mm), and insulating layer (5)
As an example, a rubber sheet with a thickness of about 5 mm is laid, and concrete is poured from the concrete mixer truck on top of it and cured by leaving it to stand, and concrete is cast with a thickness of about 100 mm as an example of the surface layer (6). Layers were formed.

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

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

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

Example 2 <Exothermic Coarse Grains> 27 parts of scaly 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 size of 5 to 15 μm, and a particle size 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, and 7 parts of nickel oxide particles having a particle size of 2 to 5 μm

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

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

Then, an electrode (4) made of an aluminum plate formed in a comb shape by punching is formed on the layer (3) of the heat-generating coarse particles.
(Distance between electrodes is 200mm), and insulating layer (5)
As an example, a polypropylene sheet with a thickness of about 1 mm is laid, and concrete is poured from it on a concrete mixer truck, and left standing to harden the surface layer.
(6) As an example, 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 use as that of the first embodiment.

Example 3 A polypropylene sheet having a thickness of about 1 mm as an example of the 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 thereover. While ejecting,
Subsequently, a grounding machine rammer was used to reduce vibrations and smooth the surface while applying vibration to form a layer (3) of heat-generating coarse particles having a thickness of about 30 mm.

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

[0058]

As described in the section of the operation, the heat-generating coarse particles of the present invention are applied on the ground (1) on the ground (1) through the insulating layer (2) to form the heat-generating coarse particle layer (3). ), And at the stage of forming the layer (3) of exothermic coarse particles, the coarse particles (C) such as gravel play a role as a structural material, and the minimum exothermic composition (AB) Can cover a wide area. In this way, in addition to being excellent in on-site workability and economical efficiency, it also has excellent heat generation performance such as good heat generation efficiency and high temperature rising rate compared to the amount of electricity supplied.

Therefore, the heat-generating structure of the present invention is most suitable for use in airfield runways, roads, parking lots, bridges, stadiums, etc. for prevention of freezing and snow, heating of stall floors, ground for greenhouses, etc. is there.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing heat-generating coarse particles of the present invention.

FIG. 2 is an explanatory view schematically showing an example of the exothermic structure of the present invention.

[Explanation of symbols]

 (A) ... conductive particles, (B) ... binder substance, (AB) ... exothermic composition, (C) ... coarse particles, (1) ... ground, (2) ... insulating layer, (3) ... exothermic property Coarse-grained layer, (4) ... Electrode, (5) ... Insulating layer, (6) ... Surface layer

Claims (4)

[Claims] 1. Conductive particles are provided on the surface of coarse particles (C) such as gravel.
(A) and the binder substance (B)
Exothermic coarse particles formed by forming the layer B). 2. The conductive particles (A) have the scale-like graphite particles (a ₁ ) as an essential component, and the conductive glue-like carbon (a ₂ ), metal particles (a ₃ ), metal salt (a ₄ ) or metal. The exothermic coarse particles according to claim 1, wherein the oxide (a ₅ ) is an optional component. 3. An insulating layer (2) is provided on the ground (1), and the layer (3) of heat-generating coarse particles according to claim 1 is further provided on the insulating layer (2), and the electrode (4) is also provided. A heat-generating structure that is installed and further has an insulating layer (5) on the layer (3) of heat-generating coarse particles. 4. The heat-generating structure according to claim 3, further comprising a surface layer (6) provided on the insulating layer (5).