DE10044375B4 - Infrared coating and with this coating, at least partially coated objects - Google Patents

Abstract

infrared Effective Coating in a flowable state has the consistency of a paint-like paint, which is an aluminum-pigmented rubber paint is self-curing and on interior and exterior surfaces, such as in cavities, columns and pores of objects in the manner of a layer by means of spatula or spray technique or brush spread applied is and for Wavelength λ> 600 nm has an emission number ε <0.2, wherein the aluminum-pigmented rubber paint a ratio of 1 g Buna rubber, 25 ml tetrahydrofuran and 8 g bare, non-oxidized Aluminum powder has.

Description

Technical area

The The invention relates to an infrared-active coating as well on objects, coated with this coating are, especially objects, the for suitable for use in the construction sector.

State of the art

Of the Desire for energy saving or reduction of energy loss plays in all technical fields, and especially in construction an increasingly big one Role, especially the claims to the thermal comfort of rooms used by people increase resources are scarce and also the energy costs Creation of a for the people pleasant living and room climate constantly rise. To these wishes To be fair, are always improvements to the heat protection raumumschließender Components and optimization of the room temperature sought.

Basically, this goal can be achieved by influencing the heat transfer coefficient α beyond the components. α is composed of a convective component α _k and a radiation-related component α _s . While α _k is essentially determined by the flow conditions prevailing at the interfaces, α _s primarily takes into account the long-wave radiation exchange with the environment. However, α _s is directly proportional to the emissivity ε (emission number) of the component surface over which the heat transfer takes place. If these surfaces are coated with infrared-active materials, ie materials with a very low long-wave radiation emission number, their radiation emission can be decisively influenced.

optimizations on building envelopes, for example Roof or wall components forming an interior of an exterior space disconnect, can by targeted reduction of their heat transfer coefficient (k-value) be made. The k value is in addition to the legend below to be taken from the following formula.

The characteristics occurring in the above formula α _i and α _a respectively correspond to the heat transfer coefficient of the air on both sides of the component, in which an energy current is passed directed from the hot to the cold side and from the inside out. A schematic representation of the radiation-induced and convective heat transfer on the outer and inner surface of a component is made 3 refer to. On the outside of the component, which is in 3 is shown in cross-section and has a hatching, outweighs there in winter due to the ever-occurring wind of the convective heat transfer α _k relative to the radiation-induced heat transfer α _s . The situation is different for the interior in winter and for the external heat transfer in summer, where the convective and radiation-related share in the heat transfer are about the same size.

If, as already explained above, one wishes to reduce the heat transfer coefficient (k value) of a component, theoretical considerations show that the heat transfer coefficients α and in particular α _{s are} to be reduced in the same way. This in turn means that a reduction in the heat transfer coefficient k, for example, by a component by the suppression or reduction of the long-wave radiation exchange between the respective heat involved body surfaces is possible. This is achieved as stated above, when the surfaces are coated with infrared active materials.

• – Gertis, K. und Erhorn, H.: Infrarotwirksame Schichten zur Energieeinsparung bei Gebäuden. Gesundheits-Ingenieur 103 (1982), H. 1, S. 20-24 und 33-34;
• – Kälin, R. und Kneubühl, F.: Die Verminderung des Wärmeverbrauches durch Infrarot-Verspiegelung von Fenstern, Fassaden und Dächern. Gesundheits-Ingenieur 98 (1977), H. 9, S 244-251;
• – Finger, G. et al.: Verbesserung des Energiehaushaltes von Gebäuden durch Verminderung der Wärmestrahlung von Fenstern und Fassaden. Schweizer Ingenieur und Architekt 17 (1979), H. 7, S. 287-294
• – Gubareff, G. G.; Janssen, J.E. und Torborg, R. H.: Thermal Radiation Properties Survey. A review of the Literature. Second edition. Honeywell Research Center, Minneapolis, Minnesota (1960))

Such materials with low radiation emission numbers are known from the literature:

• - Gertis, K. and Erhorn, H .: Infrared-active coatings for energy saving in buildings. Health Engineer 103 (1982), H. 1, pp. 20-24 and 33-34;
• - Kälin, R. and Kneubühl, F .: The reduction of heat consumption by infrared mirroring of windows, facades and roofs. Health Engineer 98 (1977), H. 9, S 244-251;
• - Finger, G. et al .: Improving the energy balance of buildings by reducing the thermal radiation of windows and facades. Swiss engineer and architect 17 (1979), H. 7, pp. 287-294
• - Gubareff, GG; Janssen, JE and Torborg, RH: Thermal Radiation Properties Survey. A review of the literature. Second edition. Honeywell Research Center, Minneapolis, Minnesota (1960))

In particular, these materials are a range of metals, metal oxides, plastics and many other organic and inorganic substances. From the diagram according to 2 the emission numbers of different materials depending on the wavelength are removable. It can be seen from the diagram that only a small number of the materials, metals, metal compounds, plastics and organic solvents mentioned are suitable for the infrared-effective coating of surfaces.

• – McIntyre, D. A. und Brailsford, J. R.: Wallpapers to cut the heating bills. Building Research and Practice (1975), H. 3, S. 88-95;
• – Weimar, R.J.; Hoffmann, A. und Leers, K. J.: Auswirkung wärmereflektierender Wand- und Deckbeläge auf die Behaglichkeit und Energieverbrauch. Elektrowärme 39 (1981), H. 2, S. A81-A90;
• – Kast, W. und Klan, H.: Energieeinsparung durch infrarotreflektierende Tapeten. Gesundheits-Ingenieur 104 (1983), H. 4, S. 181-197.

Using such materials, surfaces, cavities, gaps and pores, etc. of technical objects are provided with corresponding infrared-active material layers per se in a known manner for infrared-effective treatment. Thus, for example, in the glass industry, the above measure is used to improve the thermal insulation of insulating glass, as for example, "glasses, J .: improvement of thermal insulation in insulating glass. Glastechnische Berichte 50 (1977), H. 10, pp. 248-256. The use of infrared-reflecting layers on films or plates is also known. For example, wallpaper with infrared-effective layer materials are coated, as it is z. B. can be taken from the following articles:

• - McIntyre, DA and Brailsford, JR: Wallpapers to cut the heating bills. Building Research and Practice (1975), H. 3, pp. 88-95;
• - Weimar, RJ; Hoffmann, A. and Leers, KJ: Impact of heat-reflecting wall and ceiling coverings on comfort and energy consumption. Electric Heat 39 (1981), H. 2, pages A81-A90;
• - Kast, W. and Klan, H .: Energy saving through infrared-reflecting wallpaper. Health Engineer 104 (1983), H. 4, pp. 181-197.

In the DE 195 01 114 A1 For example, a paint having reflective properties in two wavelength ranges and absorbing properties in a third wavelength range will be described. This paint can gain energy from the near infrared range of the solar spectrum even with optically bright coloring without emitting the absorbed energy in the heat radiation in the usual way. Furthermore, it can be seen from the document that the coating in the visible range of the electromagnetic spectrum of 0.4-0.7 microns reflective and can be set absorbing in the near infrared range of 0.75-2.5 microns. In the thermal infrared range of 3-100 microns, in particular 5-50 microns, the paint has a high reflectivity at low absorption.

In the DE 38 32 555 A1 describes the use of high reflectance paints in the thermal radiation spectral region for coating objects. The objects are artificial target objects for the practice shooting of tanks on military training areas. It is explained that by providing paints containing metal particles with high electrical conductivity, surfaces with high reflectivity in the spectral region of thermal radiation can be created. Various compositions of such paints are explained, and various binders are given.

In the DE 197 45 647 A1 For example, there is disclosed a thermal insulation coating comprising one or more IR-reflective layers and a method of making the same. The thermal insulation coating reflects in the infrared wavelength range, preferably above 750 nm, in particular in the wavelength range from 751 nm to about 2000 nm, at least 40%, in particular 45% of the incident radiation. Preferably, reflectivities of at least 85% based on the incident radiation are achieved.

In the DE 43 02 375 A1 The use or arrangement of the long-wave radiation is low emitting coating on surfaces, especially of buildings, disclosed. The coating is intended to reduce a radiation exchange in the long-wave range, ie in the wavelength range of 0.8-400 μm. In this case, an emissivity for long-wave in the specified range of less than 0.9, preferably from 0.9 to 0.2, and more preferably be achieved by less than 0.2.

In the DE 20 56 211 there is disclosed a heat-reflecting paint consisting of metal particles, especially aluminum ground, which are highly reflective for beams of 3-20 μm wavelength, and a binder which absorbs beams of 3-20 μm wavelength only to a small extent.

All known measures to reduce the heat transfer Using infrared-effective materials are costly Manufacturing and processing procedures are linked and are only for special Applications suitable.

Presentation of the invention

Of the Invention is based on the object, an infrared-effective coating specify that is technically easy to produce and in particular with any technical surfaces, cavities, gaps or pores in Can be connected. In particular, the infrared-active Coating material to be capable of little or no long-wave Emit radiation. moreover should objects for use in construction, in particular for the construction of components which are provided with the infrared-active coating are and about particularly preferred, reduced heat transfer and thus heat transfer coefficients feature.

The solution the object of the invention is based in claim 1 and Claim 3 specified. The concept of the invention advantageously further Features are the subject of the dependent claims and the description with reference to the figures.

The coating according to the invention indicates in a flowable state the consistency of a paint-like paint on an aluminum-pigmented Is a rubber paint and a ratio of 1 g Buna rubber, 25 ml of tetrahydrofuran and 8 g of bare, unoxidized aluminum powder having. The paint is self-curing and applied to both interior and exterior surfaces, in cavities and gaps as well as in the pores of bodies in the manner of a layer Can be applied by brush, spatula or spray technique. moreover For example, the infrared-active coating has an emission number ε <2 for wavelengths greater than 600 nm.

Such a composite aluminum-pigmented rubber coating has, depending on the component surface temperature on particularly low emission numbers ε, as it 4a can be seen in diagram form. The in the diagram according to 4a solid line corresponds to a measurement of the above-mentioned infrared coating without dust layer. The dashed line in the diagram according to 4a corresponds to a measurement with dust. In 4b a diagram is shown showing the measurements of emission numbers as a function of the emission angle.

Especially good results with the infrared-active layer material according to the invention can be achieved when the paint is applied to objects that in itself or with at least one further object one at least partially enclosed cavity or provide a gap, in which the surfaces defining the cavity or gap with the infrared active Coating material flat are sealed. The effect of the infrared-active coating is most effective when the cavities or gaps are airtight are completed, so there convective no or as a result of Eigenkonvektion transferred little heat becomes. In this case, the heat transfer takes place almost exclusively by Radiation, so just on those surface areas that are airtight opposite to the closed cavity, the attachment of the infrared-active invention Layer experiences a particularly high effectiveness.

Such trained objects are with reference to the 1a -d shown. In 1a the cross-section of an article is shown having a completely enclosed cavity 1 provides. The surfaces of the cavity are in this case with the infrared-active coating 2 sealed. In 1b has the cavity 1 an elliptical cross-section and is also intricate with the infrared-effective coating 2 overdrawn. In the 1c and d are cracks 3 shown at the two opposing surfaces that form the gap 3 delimiting, with the inventively designed Infrarotwirksa coating 2 are sealed. Similarly, the pores in a body can also be treated.

In 5a , b are hollow block modules as they are widely used in the construction sector for building walls. The Hohlblockbausteine usually consist of bricks, pumice stone or Leichbetonmaterial and include in itself hollow chambers. According to the invention, the hollow block modules are intricate in their hollow chambers 3 with the infrared-active coating 2 lined to reduce the radiation-induced heat transfer targeted. Experiments have shown that such, provided with an infrared-active coating hollow block modules have thermal insulation properties that are 26% better than commonly used hollow block building blocks without such an infrared-effective coating. The treatment of the outer surfaces and the material pores of the hollow blocks with the coating according to the invention is also possible.

The formed according to the invention In principle, infrared-active coating can be applied to all surfaces, in all cavities, Columns and pores of any shape and geometry are applied and this with the help of usual Spray spatula or brush technique. It is especially effective when using surfaces of cavities or Encloses columns. This applies on the one hand for those already mentioned above Hollow block components, as used for building components on the Construction sector can be used. Also it is possible to interspaces of mehrschaligen Components such as floors, doors, Shutter boxes, Prefabricated components, ceilings, walls, Panel double façades, etc. with the described infrared active To provide coating.

The following Characteristics of the aluminum-pigmented rubber coating on: The emission number remains at almost all measuring temperatures in the Range between 20 ° C up to 100 ° C almost constant and thus shows virtually no temperature dependence.

Of the Painting adheres well to any substrate and gives it independent of its surface texture a smooth and even surface texture. The rubber coating is flaking not in its solid form and has a high resistance to friction.

wettings of the painting as well as strong temperature fluctuations the effectiveness of the heat transfer behavior almost not by the paint.

A There is no risk of corrosion of the bare aluminum powder since this is protected by the Buna rubber.

at Hollow block building blocks and prefabricated components in construction can be the coating already applied during production.

Also in the automotive sector and in other areas of technology, the Attachment of the coating according to the invention already during of production.

In Hollow and interstices the outside accessible are an afterthought Coating the surfaces without big ones Effort with the aid of the aforementioned application techniques possible.

Next the spray and spatula technique, with which the coating is applied to a surface can, allows in the flowable state coating also the order by mere brush painting.

The Material costs for the production of the coating material as well the necessary layer thickness is very low. In addition, the layer easy and needed little space.

There the above-described coating is a kind of paint can she without special devices with commercial Tools on the surface be applied. But it is also possible, as a spray gas or as a film.

Claims (8)

An infrared-active coating having, in a flowable state, the consistency of a paint-like paint which is an aluminum-pigmented rubber paint, self-curing and on internal and external surfaces such as voids, crevices and pores of article-like articles can be applied by means of putty or spray technique or brush application and for wavelengths λ> 600 nm has an emission coefficient ε <0.2, wherein the aluminum-pigmented rubber coating has a ratio of 1 g Buna rubber, 25 ml tetrahydrofuran and 8 g bare, unoxidized aluminum powder. Infrared active coating material according to claim 1, characterized in that the infrared-active coating material as a spray gas or film can be produced. Subject on which the infrared-active coating material according to claim 1 or 2 applied flat is, wherein the object in itself or with at least one other Subject to an at least partially enclosed cavity or provides a gap whose the cavity or gap narrowing surfaces Sealed flat with the infrared-active coating material are. Article according to claim 3, characterized that the cavity corresponds to pores within a porous material. Article according to claim 3 or 4, characterized that completely enclosed cavity partially or completely hermetically sealed is. Article according to one of claims 3 to 5, characterized that the object in the manner of a hollow block for building of masonry for building is formed with hollow chamber areas whose chamber walls with the infrared active coating are coated. Article according to one of claims 3 to 6, characterized that at least two items to include a gap in the form of multi-layer building components such as walls, ceilings, roofs, floors, doors or Shutter boxes, on their surfaces enclosing the gap, the infrared-active Layer is applied. An article according to claims 3 to 7, characterized that at least two items to include a gap in the form of multi-shell components in the automotive industry, such as bodywork part, Car doors as well Sheet metal cladding, on whose surfaces enclosing the gap infrared active coating is applied.