Process for forming an optical black surface and surface formed thereby

Claim 1

A method for 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 50 minutes: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Internal cure agent 2-10 Black pigment 17-27 Mica 0-3 Water 50-70 ______________________________________ wherein said internal cure agent is selected from the group consisting of CuO, CU 2 S, Ni 2 O 3 , and Co 2 O 3 (b) Coating the surface to be rendered optically black by (1) applying at least four coats of an alkali metal silicate and pigment composition, and (2) spraying at least the last two surface coatings, said last two surface coatings being said mixture, and (c) Curing at least said surface coatings by (1) exposing said coating to NH 4 OH, and subsequently (2) rinsing said coating with water.

Claim 2

A method for 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 50 minutes: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Internal cure agent 2-10 Black pigment 17-27 Mica 0-3 Water 50-70 ______________________________________ wherein said internal cure agent is selected from the group consisting of CuO, CU 2 S, Ni 2 O 3 , and Co 2 O 3 (b) Coating the surface to be rendered optically black by (1) applying at least four coats of an alkali metal silicate and pigment composition, and (2) spraying at least the last two surface coatings, said last two surface coatings being said mixture, and (c) Curing at least said surface coatings by (1) exposing said coating to NH 4 OH, and subsequently (2) rinsing said coating with water.

Claim 17

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, less the black pigment, approximately 1/3 of the silicate and 1/4 of the water, for a period of up to about 3 hours: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13 to 21 CuO or Cu.sub.2 S 2 to 10 Black pigment 17 to 27 Mica 0 to 3 Water 50 to 70 ______________________________________ (b) Adding said black pigment and the remainder of said silicate and said water to said mixture and continuing the ball milling for an additional period of up to 50 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 four coats of an alkali metal silicate and pigment composition, and (2) by spraying at least the last two coats, said last two coats comprising said mixture, and (e) Curing at least said surface coatings by (1) exposing said coating to NH 4 OH for at least about 16 hours, and (2) rinsing said coating with water for at least one minute.

Claim 18

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, less the black pigment, approximately 1/3 of the silicate and 1/4 of the water, for a period of up to about 3 hours: ______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13 to 21 CuO or Cu.sub.2 S 2 to 10 Black pigment 17 to 27 Mica 0 to 3 Water 50 to 70 ______________________________________ (b) Adding said black pigment and the remainder of said silicate and said water to said mixture and continuing the ball milling for an additional period of up to 50 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 four coats of an alkali metal silicate and pigment composition, and (2) by spraying at least the last two coats, said last two coats comprising said mixture, and (e) Curing at least said surface coatings by (1) exposing said coating to NH 4 OH for at least about 16 hours, and (2) rinsing said coating with water for at least one minute.