Process for forming an optical black surface and surface formed thereby

Claim 1

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of (a) Milling the following mixture of ingredients for up to about 25 minutes: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Black metal 17-27 oxide pigment Kaolin 0-5 Mica 0-3 Water 50-70 ______________________________________ (b) Coating the surface to be rendered optically black (1) by applying at least four coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two surface coatings, said last two surface coatings being said mixture, and (c) Drying at least the coats prior to the last two coats, before applying the last two coats.

Claim 2

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of (a) Milling the following mixture of ingredients for up to about 25 minutes: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Black metal 17-27 oxide pigment Kaolin 0-5 Mica 0-3 Water 50-70 ______________________________________ (b) Coating the surface to be rendered optically black (1) by applying at least four coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two surface coatings, said last two surface coatings being said mixture, and (c) Drying at least the coats prior to the last two coats, before applying the last two coats.

Claim 25

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of: (a) Ball milling a mixture of the following ingredients for a period of about 10 minutes to about 20 minutes until the mixture has achieved a sprayable consistency: ______________________________________ Ingredient Amount ______________________________________ Sodium silicate solution 270-290 milliliters Black pigment 160-170 grams Water 160-180 milliliters, ______________________________________ wherein said sodium silicate solution has a percentage weight ratio of Na 2 O to SiO 2 in the range of 1:2.40 to 1:3.75 and comprises about 50% to 70% by weight H 2 O, and said black pigment comprises the substantially black oxides of manganese, copper and iron, (b) Treating the surface to be rendered optically black in a manner which will enhance the bonding of the silicate coating to said surface, and (c) Coating the surface to be rendered optically black (1) by applyng at least five coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two coats, said coats being said mixture, and (d) Drying at least the coats prior to the two last coats before applyng the last two coats.

Claim 26

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of: (a) Ball milling a mixture of the following ingredients for a period of about 10 minutes to about 20 minutes until the mixture has achieved a sprayable consistency: ______________________________________ Ingredient Amount ______________________________________ Sodium silicate solution 270-290 milliliters Black pigment 160-170 grams Water 160-180 milliliters, ______________________________________ wherein said sodium silicate solution has a percentage weight ratio of Na 2 O to SiO 2 in the range of 1:2.40 to 1:3.75 and comprises about 50% to 70% by weight H 2 O, and said black pigment comprises the substantially black oxides of manganese, copper and iron, (b) Treating the surface to be rendered optically black in a manner which will enhance the bonding of the silicate coating to said surface, and (c) Coating the surface to be rendered optically black (1) by applyng at least five coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two coats, said coats being said mixture, and (d) Drying at least the coats prior to the two last coats before applyng the last two coats.

Claim 28

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of: (a) Milling the following mixture of ingredients for a period of up to about 3 hours: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13 to 21 Kaolin 0 to 5 Mica 0 to 3 Water 50 to 70, ______________________________________ (b) Adding black metal oxide pigment in an amount of between about 17 and 27% by weight based upon the total weight of the mixture to the mixture of step (a) and continuing the ball milling for an additional period of up to 25 minutes, (c) Preparing said surface by treating said surface in a manner which will enhance the adhesion of the silicate coating to the surface, (d) Coating the surface to be rendered optically black (1) by applying at least five coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two coats, said last two coats comprising said mixture, (e) Drying at least the coats prior to the last two coats, prior to coating on said last two coats, and (f) Heating the coating to a temperature of between about 250° C. and 350° C. for about 15 minutes to 30 minutes.

Claim 29

A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of: (a) Milling the following mixture of ingredients for a period of up to about 3 hours: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13 to 21 Kaolin 0 to 5 Mica 0 to 3 Water 50 to 70, ______________________________________ (b) Adding black metal oxide pigment in an amount of between about 17 and 27% by weight based upon the total weight of the mixture to the mixture of step (a) and continuing the ball milling for an additional period of up to 25 minutes, (c) Preparing said surface by treating said surface in a manner which will enhance the adhesion of the silicate coating to the surface, (d) Coating the surface to be rendered optically black (1) by applying at least five coats of an inorganic composition comprising alkali metal silicate and metal oxide pigment composition, and (2) by spraying at least the last two coats, said last two coats comprising said mixture, (e) Drying at least the coats prior to the last two coats, prior to coating on said last two coats, and (f) Heating the coating to a temperature of between about 250° C. and 350° C. for about 15 minutes to 30 minutes.