FILM WITH LOW HEAT CONDUCTIVITY, REDUCED DENSITY AND LOW SOLAR ABSORPTION

Abstract

The invention relates to a dark, flat element, preferably a plastic, lacquer coating or fiber material, having reduced density, low heat conductivity and low solar absorption. The flat element has a relatively high reflection infrared range of the electromagnetic spectrum reduce heating by sunlight in the near infrared dark tinting in the visible range. Low density conductivity are obtained inter alia by inserting in the near in order to area despite and low heat light filling materials into the flat element. Said flat element can be used in places where surfaces are dark tinted for aesthetic or technical reasons but should not heat up in sunlight and should give off little heat when touched by hand or by other parts of the body. Other areas of application include surfaces which should have a heat insulating effect in addition to the above-mentioned characteristics.

Claims

1-32. (canceled)

33: A film with low heat conductivity, reduced density and low solar absorption, the film comprising: at least one combination of a plastic support material and components incorporated into the plastic support material, the components incorporated into the plastic support material consisting of: a) and/or b); and at least one of c), d), and e); and optionally f), wherein: a) comprises inorganic and/or organic light fillers, which reduce the density and heat conductivity of the plastic support material; b) comprises gases selected from the group consisting of air, nitrogen, carbon dioxide, and noble gases, which form cavities in the plastic support material and reduce the density and heat conductivity of the plastic support material; c) comprises dyes, which reflect with spectral selectivity in the wavelength range of visible light from 400 to 700 nm and have an average transparency of greater than 50% in the wavelength range of the near infrared from 700 to 1,000 nm; d) comprises first pigments, which reflect with spectral selectivity in the wavelength range of visible light from 400 to 700 nm and have an average transparency of greater than 50% in the wavelength range from 700 to 1,000 nm; e) comprises second pigments, which reflect with spectral selectivity in the wavelength range of visible light from 400 to 700 nm and have an average reflection of greater than 50% in the wavelength range of the near infrared from 700 to 1,000 nm; and f) comprises inorganic and/or organic nanomaterials, which can be surface-treated or surface coated, and wherein the at least one combination has the following properties: i) an average reflection in the wavelength range of visible light from 400 to 700 nm less than 50%; ii) an average reflection in the wavelength range of near infrared from 700 to 1,000 nm greater than 50%; iii) a heat conductivity less than 0.4 (W/m K); and iv) a bulk density that lies below 1.4 g/cm.sup.3.

34: The film according to claim 33, wherein the plastic support material is selected from the group consisting of polyamides, polyacetates, polyesters, polycarbonates, polyolefins, styrene polymers, sulfur polymers, fluorinated plastics, polyamides, polymethylmethacrylates (PMMA), polyvinyl chloride, silicones, epoxy resins, polymer blends, polycarbonate-ABS, melamine resins, phenolic resins, polyurethanes, and mixtures thereof.

35: The film according to claim 33, wherein the plastic support material is both a reactively crosslinking plastic and a thermoplastic.

36: The film according to claim 33, wherein the density of the light fillers is less than 0.5 g/cm.sup.3.

37: The film according to claim 33, wherein the light fillers comprise hollow microspheres made from material selected from the group consisting of ceramic having a density less than 0.4 g/cm.sup.3, glass having a density less than 0.4 g/cm.sup.3, and plastic having a density less than 0.2 g/cm.sup.3.

38: The film according to claim 33, wherein the light fillers are plastic particles that only form hollow microspheres with a density below 0.2 g/cm.sup.3 when the plastic support material is heated to temperatures of 80 to 160 C.

39: The film according to claim 33, wherein the dyes are selected from the group consisting of acid dyes, direct dyes, basic dyes, development dyes, sulfur dyes, aniline dyes, and zapon dyes.

40: The film according to claim 33, wherein the first pigments are selected from the group consisting of monoazo, disazo, -naphthol, naphthol-AS, laked azo, benzimidazolone, disazocondensation, metal complex, isoindolinone, isoindoline phthalocyanine, quinacridone, perylene and perinone, thioindigo, anthraquinone, anthrapyrimidine, flavanthrone, pyranthrone, indanthrone, anthanthrone, dioxazine, triarylcarbonium, quinophthalone, and diketo pyrrolo pyrrole pigments.

41: The film according to claim 33, wherein the second pigments are inorganic pigments selected from the group consisting of metal oxides, metal hydroxides, cadmium pigments, bismuth pigments, chromium pigments, ultramarine pigments, coated mica pigments in the form of platelets, and rutile and spinel mixed phase pigments.

42: The film according to claim 33, wherein additional particles are incorporated in the plastic support material, the additional particles having a reflection greater than 70% in the wavelength range from 400 to 1,000 nm.

43: The film according to claim 42, wherein the additional particles of inorganic pigments are selected from the group consisting of metal oxides, metal sulfates, metal sulfides, metal fluorides, metal silicates, metal carbonates, and mixtures thereof.

44: The film according to claim 42, wherein the additional particles are degradable materials selected from the group consisting of calcium carbonate, magnesium carbonate, talc, zirconium silicate, zirconium oxide, aluminum oxide, natural barium sulfate, and mixtures thereof.

45: The film according to claim 33, wherein the element's heat conductivity is less than 0.3 (W/m.Math.K).

46: The film according to claim 33, wherein the bulk density of the element is less than 1.2 g/cm.sup.3.

47: The film according to claim 33, wherein it has an average reflection of less than 40% in the wavelength range of visible light from 400 to 700 nm.

48: The film according to claim 33, wherein it has an average reflection of greater than 60% in the wavelength range of near infrared from 700 to 1,000 nm.

49: The film according to claim 33, wherein the light fillers increase the reflection of the element by up to 10% in the near infrared range from 700 to 1,000 nm.

50: The film according to claim 33, wherein the element has at least one layer consisting of the combination.

51: The film according to claim 33, wherein the element farther includes a layer that is combined with another layer of the plastic support material that does not contain the incorporated components.

52: The film according to claim 33, wherein identical or different variants of the element are combined in at least two layers.

53: The film according to claim 33, further comprising a lacquer coating.

54: The film according to claim 33, wherein the plastic support material further comprises a device or layer.

Description

EXAMPLE

FIGURES

[0054] Heat flow through a material sample described in the examples is shown in FIGS. 1, 3 and 4. A universal heat flux sensor F-035-2, measuring 2525 mm, from the Wuntronic company, Munich, is used in these measurements, which delivers a voltage equivalent to heat flux. FIGS. 2 and 5 to 11 show as measurement results the spectral reflection of the samples for the corresponding examples in the wavelength range 400 to 980 nm. A PC-plug-in spectrometer PC 2000, from The Avantes company, with a spectral sensitivity from 320 to 1,100 nm, serves as measurement instrument, with an Ulbricht sphere connected to it to measure hemispherical backscatter of surfaces.

Example 1

Tinting and Coating of Leather for Auto Seats

[0055] A piece of leather is tinted black with the dye Sella Cool Black 10286 from TFL Ledertechnik, Basel.

[0056] The following black coating is prepared:

[0057] 15.00 g Roda Cool Black pigment preparation from TFL Ledertechnik, Basel

[0058] 60.00 g Roda Car B32 from TFL Ledertechnik, Basel

[0059] 10.00 g Roda Car P64 from TFL Ledertechnik, Basel

[0060] 10.00 g water

[0061] 01.20 g Expancel 091 DE hollow microspheres from Akzo Nobel

[0062] The coating is applied with a doctor blade three times with a layer thickness of 100 m and dried in a laboratory furnace after each layer.

[0063] The black leather so coated is placed in the laboratory furnace, together with a coated piece of leather of the same type, tinted in the standard fashion, and heated to 80 C. The leather pieces are removed from the furnace, and the heat flux from the leather sample into a 1 kg piece of lead at room temperature is measured. A universal heat flux sensor F-035-2, measuring 2525 mm, from the Wuntronic company, Munich, is used. FIG. 1 shows the heat flux of the leather with the standard finishing (1; comparison) and curve (2) shows the heat flux, lower by about 500 W/m.sup.2, of the leather sample coated according to the invention. This difference is also clearly detectable when a hand is placed on the leather samples.

[0064] The spectral reflection of the samples is measured in the wavelength range 400 to 980 nm (measurement instrument: PC-plug-in spectrometer, PC 2000, from The Avantes company, with a spectral sensitivity from 320 to 1,100 nm, with an Ulbricht sphere connected to it to measure hemispherical backscatter of surfaces); the measurement results are shown in FIG. 2:

[0065] Curve (1) shows the clearly higher reflection in the near infrared range of the black leather coated according to the invention. Reflection of the standard reference leather (2) lies below 10% also in the near infrared range. Both black leather samples are placed on a Styrofoam plate and exposed to about 800 W/m.sup.2 strong solar radiation. The surface temperature of the standard leather rose to 90 C., and that of the leather according to the invention, on the other hand, only to 62 C. The density of the coated leather according to the invention lies at 0.85 g/cm.sup.2 and the heat conductivity at 0.12 W/mK. The density of the standard coated leather lies at 1.1 g/cm.sup.3 and the heat conductivity at 0.15 W/mK. The density of the coated leather according to the invention is therefore 23%, and the heat conductivity 20% less than in the standard leather coated according to the prior art.

Example 2

Reduction of Density and Heat Conductivity of a Leather

[0066] A leather sample is placed in a water bath. 20 wt. % (referred to the weight of the leather) of unexpanded hollow microspheres of the Expancel 820SL80 type from Akzo Nobel are added to the water bath and incorporated in the leather by the usual process in a tannery. The leather is then tinted black with the dye Sella Cool Black 10286 from TFL Ledertechnik, Basel. The leather is placed into a furnace at about 100 C., until the hollow microspheres expand under the influence of heat and fill up part of the cavities in the leather.

[0067] One piece of the leather so produced according to the invention is placed onto a heating plate at 54 C., and heat transfer from the heat plate through the leather into a 1 kg water beaker with a water temperature of 7.5 C. is measured with the heat flux sensor F-035-2. The same procedure is carried out with a black standard leather (comparison).

[0068] The time trend of heat flux through the leather samples is shown in FIG. 3 in W/m.sup.2. Here, curve (1) shows the heat flux through the standard leather (comparison). The heat flux through the black leather sample (2) prodUced according to the invention is then about 200 W/m.sup.2 lower. The density of the leather processed according to the invention lies at 0.85 g/cm.sup.3, and the heat conductivity at 0.1 W/mK. The density of the standard produced leather lies at 1.1 g/cm.sup.3 and the heat conductivity at 0.14 W/mK. The density of the leather processed according to the invention is therefore 23% lower, and the heat conductivity is 28% lower than in the comparison leather produced in standard fashion.

Example 3

Combination of a Leather Sample Produced According to Example 2 with a Coating Produced According to Example 1

[0069] A coating according to example 1 is applied three times with 100 m layer thickness to a leather produced according to example 2, and dried. The leather according to the invention is placed on a heating plate at 58 C., and the heat transfer from the heating plate through the leather into a 1 kg water beaker with a water temperature of 0 C. (ice water) is measured with the heat flux sensor F-035-2. The same procedure is carried out with a black, coated standard leather (comparison).

[0070] FIG. 4 shows the curve (1) of heat flux through the black standard leather (comparison). The heat flux through the leather (2) produced according to the invention is clearly lower.

[0071] The spectral reflection of the two black leather samples is measured as described in example 1, and is identical to the curves in FIG. 2. Curve (1) in FIG. 2 shows the spectral reflection of the leather produced according to the invention and curve (2) that of the standard leather (comparison). The density of the combination of leather and coating according to the invention lies at 0.82 g/cm.sup.3 and the heat conductivity at 0.09 W/mK. The density of the leather produced in standard fashion lies at 1.1 g/cm.sup.3 and the heat conductivity at 0.15 W/mK. The density of the combination according to the invention is therefore 25% lower, and the heat conductivity is 40% lower than in the comparison leather produced in the standard fashion.

Example 4

Polypropylene Component with Low Heat Conductivity and High Solar Reflection

[0072] Two samples for interior fittings of a car, based on polypropylene, are produced according to the following formulation:

[0073] a.) 600.00 g polypropylene granulate

[0074] 040.00 g SilCell 300 light filler from Chemco

[0075] 050.00 g Hombitan R610K, titanium dioxide from Sachtleben

[0076] 010.00 g Aerosil TT600 from Degussa

[0077] 020.00 g Hostaperm Blue R5R from Clariant

[0078] 010.00 g Paliogen Black L0086 from BASF

[0079] Dark blue sample plates were produced with a laboratory extruder.

[0080] b.) 600.00 g polypropylene granulate

[0081] 030.00 g Hombitan R610K, titanium dioxide from Sachtleben

[0082] 010.00 g Aerosil T600 from Degussa

[0083] 020.00 g Hostaperm Blue R5R from Clariant

[0084] 010.00 g Paliogen Black L0086 from BASF

[0085] The mixture is foamed in an extruder with carbon dioxide gas. Dark blue sample plates are produced. The density of the sample plate a) lies at 0.79 g/cm.sup.3, that of the sample plate b) at 0.74 g/cm.sup.3; the heat conductivity of the sample plate according to a) lies at 0.15 W/mK and that of sample plate b) at 0.13 W/mK. The density of the standard component (comparison) lies at 1.05 g/cm.sup.3 and the heat conductivity at 0.24 W/mK. The density of the sample plate a) therefore lies 25%, and the density of sample plate b) 29.5% below the density of the standard component. The heat conductivity of the sample plate a) lies 37%, and that of sample plate b) 46% below the heat conductivity of the standard component. The spectral reflection of sample plates a) and b), and a piece of a standard component in the same dark blue tint (comparison) is measured with the spectrometer described in example 1 in the wavelength range 400 to 980 nm.

[0086] FIG. 5 shows the results of the measurement. Curve (1) shows the reflection of sample plate a), curve (2) that of the sample plate b), and curve (3) shows that the reflection of the standard component in the wavelength range of near infrared from 700 nm is only below 10%. The samples are placed on a Styrofoam plate and exposed to 800 W/m.sup.2 solar radiation. Under these conditions, the surface temperature of the standard plate rises to 85 C., the surface temperature of the sample plates according to the invention lies at 60 C.

Example 5

Production of a Sample Plate From Epoxy Resin According to the Invention and Comparative Example

[0087] A dark anthracite-colored sample plate of epoXy resin is produced according to the following formulation (invention):

[0088] 45.00 g epoxy resin L,160 from MGS Kunstharzprodukte GmbH, Stuttgart

[0089] 03.00 g light filler Silcell 300 from Chemco Chemieprodukte GmbH

[0090] 01.00 g titanium dioxide Hombitan R610K from Sachtleben

[0091] 02.00 g Paliogen Black L0086, BASF

[0092] 15.00 g H160 curing agent from MGS Kunstharzprodukte GmbH, Stuttgart

[0093] The sample plate had a density of 0.8 g/cm.sup.3 and the heat conductivity was 0.2 W/mK.

[0094] A dark anthracite-colored epoxy resin plate with standard pigmentation according to the following formulation was prepared as a comparative example:

[0095] 45.00 g epoxy resin L160 from MGS Kunstharzprodukte GmbH, Stuttgart

[0096] 05.00 g commercial black iron oxide

[0097] 10.00 g talc from Wema, Niirnberg

[0098] 00.50 g titanium dioxide Hombitan R610K from Sachtleben

[0099] 15.00 g H160 curing agent from MGS Kunstharzprodukte GmbH, Stuttgart

[0100] The density of the standard plate was at 1.3 g/cm.sup.3 and the heat conductivity 0.3 W/mK. The density of the plate according to the invention is therefore 38% lower, and the heat conductivity is 33% lower than in the standard reference plate.

[0101] The spectral reflection of the two sample plates is measured with the spectrometer described example 1 in the wavelength range 400 to 980 nm. Curve (1) in the diagram of FIG. 6 shows the spectral reflection of the epoxide sample plate according to the invention and curve (2) the reflection of the sample plate of a comparative example. The reflection of the sample plate according to the invention is clearly higher in the near infrared range from 700 nm, which means that it absorbs less sunlight than the counter-example sample plate that is identically colored in the visible range. The samples were placed on a Styrofoam plate and exposed to 800 W/m.sup.2 solar radiation. Under these conditions, the temperature of the plate according to the invention rises to only 60 C. and that of the comparative example to 85 C.

Example 6

Preparation of a Film According to the Invention From Soft PVC and Comparative Example

[0102] A black film of soft PVC is prepared according to the following formula:

[0103] 200.00 g commercial PVC with plasticizer

[0104] 012.00 g light filler SilCell 300 from Chernco Chemieprodukte GmbH

[0105] 003.50 g titanium dioxide Hombitan R610K from Sachtleben

[0106] 007.50 g Paliogen Black L0086, BASF

[0107] The density of the PVC film according to the invention is 0.95 g/cm.sup.3 and the heat conductivity 0.12 W/mK. The density of the commercial comparison film is 1.3 g/cm.sup.3 and the heat conductivity 0.18 w/mK. The density of the PVC film according to the invention is therefore 27% lower, and the heat conductivity is 33% lower than in the commercial comparison film. The spectral reflection of the PVC film is measured with the spectrometer described in example 1 in the wavelength range 400 tc 980 nm. A commercial black film of soft PVC serves as comparative example. The measurement results are shown in FIG. 7. Curve (1) shows the increased reflection in the near infrared range of the film produced according to the invention, and curve (2) shows the reflection of the commercial black film. The samples are placed on a Styrofoam plate and exposed to 800 W/m.sup.2 solar radiation. Under these conditions, the temperature of the commercial film rises to 90 C., that of the film according to the invention, however, only to 60 C.

Example 7

Preparation of a Textile Coated on Both Sides for Blinds

[0108] A base textile for the curtain series Plaza Plus from Hunter Douglas Australia is coated on one side according to the following formulation:

[0109] Base coat:

[0110] 70.00 g binder Acronal 18D from BASF

[0111] 15.00 g pigment preparation Hostatint White, the Hoechst company

[0112] 05.00 g light filler Expancel 551WE20

[0113] After drying, an anthracite-colored cover coat is applied to this base coat in the tint of ebony from Plaza Plus of Hunter Douglas.

[0114] Cover coat:

[0115] 10.00 g water

[0116] 10.00 g pigment preparation Roda Cool Black, TFL Ledertechnik company

[0117] 40.00 g binder Acronal 18D from BASF

[0118] 05.00 g water

[0119] 01.00 g Hostatint White, the Hoechst company

[0120] The back side of the textile was coated twice with the white base coat.

[0121] The density of the textile according to the invention is 1.1 g/cm.sup.3 and the heat conductivity 0.15 W/mK. The density of the commercial counter-example is 1.3 g/cm.sup.3 and the heat conductivity 0.22 W/mK.

[0122] The density of the textile according to the invention is therefore 15% lower, and the heat conductivity is 32% lower than in the commercial counter-example. The spectral reflection of the anthracite-coated front side of the textile is measured with the spectrometer described in example 1 in the wavelength range 400 to 980 nm. Curve (1) in FIG. 8 shows the spectral reflection of the textile produced according to the invention, and curve (2) the reflection of the original curtain material ebony from the curtain series Plaza Plus from Hunter Douglas, Australia. The reflection here is below 10% as in the visible range. The samples were placed on a Styrofoam plate and exposed to 900 W/m.sup.2 solar radiation. Under these conditions, the front side of the comparison curtain material is heated to 90 C.; that of the invention, on the other hand, only to 52 C. During use of the material according to the invention as blinds, the heat flux through the curtain into a space is 30% lower than in the comparison material under the following conditions:

[0123] Solar radiation 900 W/m.sup.2

[0124] Outside temperature 25 C.

[0125] Room temperature 21 C.

Example 8

Preparation of a Sample Plate for PVC Window Profiles with Dark Surface

[0126] 20 wt. % hollow microspheres of the type S38HS from the 3M Company, are added to a commercial white-tinted PVC granulate for the production of window profiles. A sample plate of 5 mm thickness is prepared in a laboratory extruder. Furthermore, 3 wt. %, relative to the amount of PVC granulate, Hostaperm Blue R5R from the Clariant company and 1.5 wt.% Paliogen Black L0086 from the BASF company are added to a commercial clear PVC granulate for production of PVC film, and melted and mixed in a laboratory extruder. A dark blue film of 300 m thickness is produced. The film is glued with a clear hot-melt adhesive to the white PVC plate under pressure.

[0127] The density of the dark blue test sample for the window profile (invention) lies at 1.18 g/cm.sup.3 and the heat conductivity 0.14 W/mK. The density of a commercial PVC window profile (comparison) lies at 1.60 g/cm.sup.3 and the heat conductivity at 0.2 W/mK. The density of the comparison example according to the invention is therefore 26% lower, and the heat conductivity is 30% lower than in the commercial comparison profile. The spectral reflection of the plate is measured with the spectrometer described in example 1 in the wavelength range 400 to 980 nm, and compared with a commercial part of a dark blue-colored window profile. The measurement results are shown in FIG. 9. Curve (1) shows the distinctly higher reflection in the near infrared of the sample of a PVC window profile produced according to the invention. In the commercial dark blue part of the PVC window profile, the reflection in the near IR remains below 10%. The plates were exposed to 900 W/m.sup.2 sunlight. The surface of the commercial plate reached a temperature of 90 C. and deformed slightly. The surface temperature of the plate according to the invention was only 60 C. and no deformation could be found. With use of the PVC window profile according to the invention under the following conditions:

[0128] Solar radiation 900 W/m.sup.2

[0129] Outside temperature 25 C.

[0130] Room temperature 21 C.,

[0131] the heat flux through the window frame into a room is 35% lower than in the standard material.

Example 9

Preparation of a Brown-Colored Concrete Roofing Tile with Low Heat Conductivity

[0132] A sample plate of a concrete roofing tile is prepared according to the following formulation (invention):

[0133] 35.00 g Portland cement from the Lugato company

[0134] 05.00 g titanium dioxide Rutil Hombitan R210 from the Sachtleben company

[0135] 10.00 g light filler SilCell 300 from the Chemco company

[0136] Water is added to the mixture, until a flowable consistency is achieved, whereupon the mixture is introduced to a mold and dried in a furnace. The dry concrete roofing tile is provided with a dark reddish-brown coating of the following formula:

[0137] 140.00 g Acronal 18D from the BASF company

[0138] 010.00 g Langdopec Red 30000 from the SLMC company

[0139] 010.00 g Ferro PK 4047 Green from the Ferro company

[0140] 007.50 g Sylowhite SM 405 from the Grace company

[0141] 000.60 g defoamer Byk 024 from the Byk company

[0142] 000.60 g pigment distributor N from the BASF company

[0143] 000.40 g thickener Acrysol T 615 from the Rohm and Haas company

[0144] 015.00 g water

[0145] The spectral reflection of the dark reddish-brown concrete roofing tile is measured with the spectrometer described in example 1 in the wavelength range 400 tc 980 nm. As comparative example, a commercial concrete roofing tile in the tint dark brown C021 from the Kubota company in Japan is used. The measurement results are shown in FIG. 10. Curve (1) shows the distinct increase in reflection in the near infrared of the concrete roofing tile produced according to the invention, and curve (2) shows that the reflection of the commercial concrete roofing tile in the near infrared is even somewhat lower than in the visible wavelength range.

[0146] During heating of the roofing tiles and 850 W/m.sup.2 sunlight, the surface of the commercial roofing tiles heated to 87 C. and that of the tile according to the invention only to 51 C. The density of the roofing tile according to the invention is 0.7 g/cm.sup.3, and the heat conductivity 0.16 W/mK. The density of the commercial roofing tile was 1.6 g/cm.sup.3, and the heat conductivity 0.87 W/mK. The density of the roofing tile according to the invention is therefore 56% lower, and heat conductivity is 82% lower than in the commercial concrete roofing tile.

[0147] With use of the concrete roofing tile according to the invention under the following conditions:

[0148] Solar radiation 850 W/m.sup.2

[0149] Outside temperature 25 C.

[0150] Room temperature 21 C.,

[0151] the heat flow through a roof into the roof space is 45% lower than with the standard material.

Example 10

Combination of an External Plaster with a Solar-Reflecting Exterior Wall Paint

[0152] A 2 cm thick plate, produced form an exterior plaster from the Colfirmit Rajasil company with the name Ultralight plaster, is coated with a light green exterior wall paint according to the following formulation.

[0153] 200.00 g Acrylor FS White from the Relius Coatings company

[0154] 010.00 g pigment preparation Roda Cool Black from the TFL Ledertechnik company

[0155] For comparison, an exterior wall paint from the Sonneborn company USA in the tint Drumhill Grey 458-M is applied to a 2 cm thick plate of commercial plaster.

[0156] The spectral reflection of both plaster plates is measured with the spectrometer described in example 1 in the wavelength range 400 to 980 nm. The measurement results are shown in FIG. 11. Curve (1) shows that the reflection of the combination of an exterior plaster with a solar-reflecting exterior wall paint produced according to the'invention is higher in the near infrared range than the reflection in the near IR of the plaster plate coated in the standard manner, shown by curve (2).

[0157] The total density of the combination according to the invention is 0.9 g/cm.sup.3. The total density of the standard combination is 2.2 g/cm.sup.3. The heat conductivity of the combination according to the invention of a light plaster with a solar-reflecting paint is 0.12 W/mK, that of the standard combination 0.87 W/mK. The total density of the combination according to the invention is therefore 59% lower, and the heat conductivity is 86% lower than in the standard combination.

[0158] When the combination according to the invention is used on a 20 cm thick concrete wall under the following conditions:

[0159] Solar radiation 800 W/m.sup.2

[0160] Outside temperature 25 C.

[0161] Room temperature 21 C.,

[0162] the heat flux through the wall into the house is 42% lower than in the standard material.