ITUB20151080A1 - ELECTROTHERMIC COMPOSITION OF WATER BASED CARBON COMPOUNDS AND APPLICATION METHODS - Google Patents

Description

ELECTROTHERMAL COMPOSITION OF AC-QUOSA BASED CARBON COMPOUNDS AND APPLICATION METHODS

The present invention relates to the realization of a composition endowed with properties? ? electrothermal ?, in particular a high conductivity composition? electric and heat, suitable for use in paints, resins and cementitious materials.

AND? ever increasing, in the pi? various applications, the request for an economically sustainable composition that may be able to conduct electricity and heat, typically to increase comfort? in the activities? housewives and professionals. These products are formulated to offer maximum energy savings and be easily usable even directly from renewable energy sources, such as the optoelectronic devices that make up the current photovoltaic panels. With the development of fossil fuel saving policies, does research? aimed at finding solutions aimed at reducing heat dispersion and therefore making the sources in direct contact with the area where you want to have the certainty of a certain temperature punctual.

Since the properties have long been known? of carbon, in the allotropic form of graphite, in terms of heat transmission, various attempts have been made to find products capable of offering promising results in terms of yield, economic and practicality? use, typically providing cementitious pastes with graphite flakes inside, in which the graphite, suitably heated, transmitted heat to the surrounding area. However, this solution provided limited performance in terms of long-term well-being, and was evidently not very versatile in practical use.

Furthermore, with the revolution in lighting technology of LED lights, which require limited power, and which possess high versatility? of uses, the request for good surfaces conducting electricity for a simple and stable connection yes? made much more? loud.

Purpose of the present invention? therefore, to obtain a composition of electrically and thermally conductive material, which can be used in multiple fields of application, possibly also on structures, whether building or not, already? existing.

Said purpose? made by means of a high conductivity composition? electric and heat characterized which? composed of a mixture of fine-grained graphite and powder of at least one of the Elements of the Periodic Table corresponding to the Group of Transition Elements, at least one of the Alkaline Earth, Carbon and Tin Metal Elements, their alloys and / or their oxides.

The secondary claims relate to particularly preferred characteristics of the invention according to the invention.

The invention is now described with reference to some preferred embodiments, which will have purely illustrative purposes.

In order to find a composition containing graphite and additive elements that enhance on the one hand the properties? conductivity electrical and thermal and that on the other hand they turned out to be particularly versatile in their form of marketing and implementation, the inventors first of all wanted to identify the elements and their compounds that could satisfy the needs of versatility. and conductivity.

Therefore, some components corresponding to the Group of Transition Elements and some included between non-metals and alkaline-earth metals have been identified in the Periodic Table of the Elements, with particular reference to: Carbon, Magnesium, Iron, Aluminum, Copper, Silver, Nickel, Tin, Zinc, Tungsten, Titanium, with their alloys, such as steels and cast iron, carbon magnesite or with oxides, such as iron, aluminum or magnesium oxides.

Are these components very different from each other for resistivity? electrical, and therefore the choice of components to use varies according to the properties? electrical and heat to be obtained, and the relative yield. In particular, for the properties? intrinsic of the single elements, the best performances are obtained with carbon-containing compounds.

Considering the rarity? of the components, their cost and above all the ecological aspect, yes? preferred to postpone the use, for example, of tungsten powder and nickel-chromium, however with excellent properties? conductivity electrical and thermal yield, to prefer without any doubt the use of carbon, its compounds and its interactions with other elements. To be able to define suitable formulas for different applications, yes? found that the particle size of the materials used had to have specific dimensions.

To this end, yes? it was possible to experimentally ascertain that the graphite-based matrix should have a fine particle size, between 0.02 mm and 1 mm, according to the nature and thickness of the heating product to be obtained. The dimensions of the additive elements vary according to the desired state of aggregation.

So that? the composition can conduct heat and electricity, it is expected the presence of electrical contacts for connection to a voltage generator. According to the composition and size of the artifact as well as? its resistivity values? electric, with adequate protections, the connection can? be carried out directly at 220 Volt mains voltage. In common practice, it is preferred to use a very low voltage generator, not exceeding 15 Volts, preferably at most? of 12 Volt.

In a preferred embodiment, yes? wanted to create a water-based paint with properties? of conduction of electricity? and above all of heat generation, that is a paint that heats up when subjected to the passage of an electric voltage, both direct current and alternating current. The binder pi? suitable and cheap? been identified in the combination of Polyvinyl Alcohol (PVA) with Polyvinyl Acetate (PVAc) in aqueous solution. Also to prevent the deposition of graphite powder and any other complementary powders? Xanthan Gum was used.

A formula that offers great results? the following:

Compound Weight

PVAc in aqueous solution at 40% by weight 70.00 g.

PVA 4-98 in aqueous solution at 7% by weight 90.00 g.

Xanthan gum 0.33 g.

Silver Graphite (carbon 85/87% by weight 83.00 g.

fineness 85% <75micron)

For a warming water-based paint, the optimum fineness should be around 25/50 my.

The mixture of the above composition has led to a liquid substance, with properties? of adhesion on many types of supports, with resistance to abrasion, water resistance and also flexibility. This paint, with excellent spreadability,? therefore able to guarantee the necessary capacity? to adhere to surfaces, generating heat with excellent performance in terms of heating, as well as? for ecological answers, economy? and for energy savings due to the direct heating of an entire surface more? homogeneous compared to wire conductors or traditional pipes.

The electrical voltage to the paint is preferably transmitted through metal contacts preferably made of stainless steel arranged in parallel and with marked adhesion.

To allow the best transmission of electricity, and consequently the best heat distribution, yes? found, after experimental tests, that the mesh strips, preferably screwed to the edges of the painted surface, are the best solution? suitable. Alternatively, the suitably anchored aluminum or steel strips showed a good response, as well as? highly conductive low resistivity paints. Thanks to the particular viscosity, the heating varnish cos? obtained is applied by brush or spray and? fast drying having a high dryness value. This paint and its electrical contacts can be coated and protected with other paints, including solvent-based paints, insulating enamels, silicone substances, fillers and other non-conductive materials, without particular limitations.

There are numerous applications that can affect this heating paint and among these those that can be considered more? interesting are: 1 - application on insulating panels such as polystyrene and polystyrene, where the heating effect is enhanced by the fact that the support does not trap the underlying heat but allows it to be diffused above the surface, favoring its performance.

2 - application on pipes to isolate from the cold or heat the liquids contained.

3 - application on containers, such as tanks or bottles.

4 - application on various types of panels such as alveolar polycarbonate, PVC, various types of plastic, concrete, plasterboard, ceramic, terracotta, glass, wood, leather, etc.

5 - application on sheets of flexible materials, such as rubber, fabrics, paper and cardboard.

6 - Application inside boxes and jars to donate or conserve heat.

The energy that is required to heat? naturally depending on the type of material and the surface to be heated, according to the principles of thermodynamics. The homogeneity? of the heat that develops directly on the surface? the first reason for energy saving and maximum yield compared to traditional systems.

A second form of execution? aimed at creating a powder composition that allows to obtain solid resin and cementitious products, with the insertion of a conductive compound according to the objective of heating and conductivity? electric you want. It is sufficient to associate the heating conductor element with a common Portland cement alone or with clays, kaolins, bentonites and resins. According to the invention yes? in fact, I was able to ascertain that in this way the insulating effect of the compound is enhanced.

As for the paint, also for the solid formulation the best performances are obtained without any doubt with the use of Carbon, its compounds and its integrations with the other elements of the periodic table listed above.

Typically, yes? found that the grain size of the Graphite between 0.25 mm and 0.65 mm offers greater efficiency in terms of heating the obtained product. Furthermore, experimental tests have shown that the shape of the granules should preferably be flakes: yes? found that in this way the resistance? major and major? the heat generated in the product.

As in the case of the previous embodiment, the cement composition is supplemented with polyvinyl alcohol (PVA).

For the construction of a heating panel you can? proceed in three different ways:

1 - the treatment of a surface of any nature mentioned above, with the carbon heating paint applied according to the method described and covered with a layer of cement or resins of the desired thickness. This can? be called the "Sandwich" method.

2 ? the realization of a cement mortar obtained by mixing with the Carbon heating paint, equipped with metal conductors preferably in stainless steel as indicated for the paint.

3? mixing of a cementitious powder, or similar, with carbon in the form of Graphite, with a powder binder such as Polyvinyl Alcohol and preferably with a conductor in not very fine powder, (0.5 / 1.5mm) such as the filing of cast iron, magnesium oxide or carbon magnesite. Subsequently, at the moment of use, water must be added to create a mortar as usual. The conducting poles of the stainless steel or even simply carbon steel are directly embedded in the mortar, in such shapes and sizes as to offer a homogeneous distribution of the electrical voltage. Also in this case, as for the paint, the electrodes are held opposite to the extremes of the product, but unlike the paint they can also be configured as reinforcement networks of the cementitious material, both opposite and overlapping, obviously without contact between them. ? the intervening material which constitutes the heating resistance.

A typical formula for the powder product? the following:

COMPOUND WEIGHT

0.25 / 0.65mm granular graphite 250 g.

Cast iron filings (0.5 / 1.5mm) 150 g.

Polyvinyl alcohol (PVA) 4-88 SF 12 g.

Portland cement 325 250 g.

So that? the mixture can be poured into a mold, spread out or spread, is it expected to add a quantity? d? water of about 200 g.

In practice, the composition according to the invention is mixed with the substrate to be used, such as for example Portland cement and is then treated according to the modalities. conventional.

In the case of paint, it is well understood that this solution allows the deposition of a conductive layer on any surface, demonstrating considerable versatility.

In the case of a building insulation, such as polystyrene, applying an insulation panel to the outer surface increases the heat output and reduces the heating costs of the walls. Such a solution, in the? Insulating coats? polystyrene therefore reduces the risk of mold creation.

? in any case it is possible to provide a cellulose sheet with a thin layer of heating varnish, which on the one hand offers conductivity? electric and heat and on the other offers considerable flexibility.

In the case of a cementitious composition, on the other hand, there can be multiple uses: the construction of entire conductive walls, or specific artifacts endowed with the properties? conductivity electric and heat, such as for example panels, tiles, tiles, pots or saucers that can be heated to create small greenhouses.

Understandably, the conduction of electric voltage also allows the use of the surfaces treated with the composition according to the invention for the attachment of light bulbs, or light strips in contact. These solutions can prove useful both for ornamental reasons and to ensure safety in confined or poorly lit areas, typically in public places or other areas where it is advisable to indicate escape routes without necessarily providing annoying burglaries or invasive structures.

The intended purposes have therefore been achieved. The inventors have in fact produced in the embodiments described above a composition which can be used both to create a cement mortar capable of transmitting heat and electricity (electro-thermal mortar), and a water-based paint, for electrical and heat conduction, (electro-thermal paint).

Naturally, as happens in all cases of voltage management, the desired temperature regulation is regulated by a potentiometer and its maintenance by a common thermal probe.

So ? a new composition and an application method has been created that can give graphite, a basic element universally known for conducting current and heat, the necessary properties? to obtain a versatile basic product, which can undergo the necessary subsequent treatments to obtain artifacts that possess the capacity? conductivity electricity and heat production calibrated according to need.

Yup ? also? obtained a valid method to homogeneously heat, and more, substances otherwise difficult to heat with traditional coil systems or the like. For example, in the case of polystyrene and polystyrene, but also of plastic materials such as alveolar polycarbonate, a coil heating becomes impossible in addition to a modest temperature. the wire, which concentrates all the heat in itself, sinks into the support, while the application of the paint just described allows to obtain an extended and homogeneous surface heating with high performance along the entire surface, reaching the maximum temperature supported by the support without castings by homogeneously heating its entire surface.

Similar results can also be observed in solid resinous and cementitious substrates.

It is now understood that the description has concerned two preferred embodiments, which are not to be considered limiting for the scope of the present invention, which defined by the attached claims.

Claims (2)

CLAIMS 1) High conductivity composition? electric and heat characterized by there? that ? composed of a mixture of fine-grained graphite and powder with at least one of the Elements of the Periodic Table corresponding to the Group of Transition Elements, at least one of the Alkaline Earth, Carbon and Tin Metal Elements, their alloys and / or their oxides. 2) Composition as in 1) characterized by what? that these elements are Magnesium, Iron, Aluminum, Copper, Silver, Nickel, Zinc, Tungsten, Titanium, 3) Composition as in 1) characterized by what? that said alloys are steels, cast iron, magnesite or carbon magnesite. 4) Composition as in 1) characterized by what? that said oxides are iron, aluminum or magnesium oxides. 5) Composition as in 1) characterized by what? that ? further added polyvinyl alcohol (PVA) in liquid or powder form. 6) Composition as in any one of claims 1) to 5) characterized by that? that said graphite powder has a particle size between 0.01 mm and 1.5 mm. 7) Composition as in any one of claims 1) to 5) characterized by that? that said graphite powder has a particle size of between 0.02 mm and 1.0 mm. 8) Composition as in any one of claims 1) to 5) characterized by that? what said polyvinyl alcohol (PVA) in liquid form? in concentrations ranging from 5% to 20% by weight. 9) Composition as in 5) characterized by what? that ? further added polyvinyl acetate (PVAc). 10) Composition as in any one of claims 1) to 5) characterized by that? what said composition? mixed with a cement or with cement resin. 11) Composition as in 10) characterized by ci? what the grain size of graphite? between 0.25 mm and 0.65 mm. 12) Use of a composition as in any one of claims 1) to 9) as a water-based paint conducting heat and electricity. 13) Use of a composition as in any one of claims 10) and 11) as a cementitious mortar conducting heat and electricity. 14) Use of a combination of the composition of any one of claims 1) to 9) and of any one of claims 10) and 11) as a heating and electrically conductive surface. 15) Method for homogeneously heating a surface of plastic material characterized by ci? that the following phases are foreseen: - apply a pair of electrodes to the ends? opposite of said surface, - applying on said surfaces a paint having the characteristics according to claims 1) to 9), - connecting a source of electrical energy to said electrodes. 16) Method for homogeneously heating a cement surface, characterized by the fact that the following phases are foreseen: - preparing a cement mixture according to claims 10) to 12); - spread the cement mixture to form the desired surface, - apply a pair of electrodes to the ends? opposite of said surface; - connecting a source of electrical energy to said electrodes. 17) Conductive surface of heat and electric energy composed of the composition of any one of claims 1) to 9) prepared for use according to claims 10) to 12) characterized by this which further provides electrodes held opposite each other at its ends.