Acidic hydrosols and process for coating therewith

Claim 2

An acidic hydrosol composition consisting essentially of the initial constituents water, an acid selected from the group consisting of phosphoric acid, nitric acid, hydrochloric acid and acetic acid, a metal silicate selected from the group consisting of alkali metal metasilicates having the formula M 2 SiO 3 , alkali metal orthosilicates having the formula M 4 SiO 4 , where M is sodium or potassium, and hydrous magnesium silicate, magnesium compound selected from the group consisting of magnesium oxide and magnesium hydroxide, and a boron compound selected from the group consisting of boric oxide and boric acid, wherein said constituents are present in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ (A) Water About 43 to about 94 (B) Acid About 3 to about 51 (C) Alkali metal 0 to about 16 metasilicate (D) Alkali metal 0 to about 16 orthosilicate (E) Hydrous magnesium 0 to about 18 silicate (F) Magnesium compound 0 to about 6.6 (G) Boron compound 0 to about 1 ______________________________________ wherein: when (C) is O, then (D) is at least 1% and (F) is at least about 0.5%; when (D) is O, then (C) is at least 1% and (F) is at least about 0.5%; when both (C) and (D) are O, then (E) is at least about 0.9%; when (C) and (E) are each zero, then (D) is at least 1% and (F) is at least 0.5%; when (D) and (E) are each zero, then (C) is at least 1% and (F) is at least 0.5%; when (C) is zero, then (D) is greater than zero but less than l% when (E) is at least 0.9%; when (D) is zero, then (C) is greater than zero but less than 1% when (E) is at least 0.9%; the concentration of acid is at least the stoichiometric quantity required to react with either (C), (D) or (E), or with mixtures thereof to form silicic acid; and the ratio of M 2 O to SiO 2 is from about 1:1 to about 2:1 in said alkali metal metasilicates and orthosilicates.

Claim 3

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is sodium metasilicate, the magnesium compound is magnesium oxide, and the concentration of each of the constituents (D), (E) and (G) is zero.

Claim 4

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is sodium metasilicate, the magnesium compound is magnesium hydroxide, and the concentration of each of the constituents (D), (E) and (G) is zero.

Claim 5

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is sodium orthosilicate, the magnesium compound is magnesium oxide, and the concentration of each of the constituents (C), (E), and (G) is zero.

Claim 6

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate and hydrous magnesium silicate, and the concentration of each of the constituents (C), (D), (F) and (G) is zero.

Claim 7

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is hydrous magnesium silicate, the magnesium compound is magnesium oxide, and concentration of each of the constituents (C), (D) and (G) is zero.

Claim 8

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is hydrous magnesium silicate and the magnesium compound is magnesium hydroxide, and the concentration of each of the constituents (C), (D) and (G) is zero.

Claim 9

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is sodium metasilicate, the magnesium compound is magnesium oxide and the boron compound is boric oxide, and wherein the proportions thereof are as follows: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium oxide 1 to 5 Boric oxide 0.02 to 1, ______________________________________ and the concentration of each of the constituents (D) and (E) is zero.

Claim 10

The hydrosol of claim 1 wherein the acid is phosphoric acid and the metal silicate is hydrous magnesium silicate, and wherein the proportions thereof are as follows: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous Magnesium Silicate 1 to 12, ______________________________________ and the concentration of each of the constituents (C), (D), (F) and (G) is zero.

Claim 11

The hydrosol of claim 1 wherein the acid is phosphoric acid, the metal silicate is hydrous magnesium silicate, the magnesium compound is magnesium oxide and the boron compound is boric oxide, and wherein the proportions thereof are as follows: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 5 to 20 Hydrous magnesium silicate 1 to 5 Magnesium oxide 1 to 5 Boric oxide 0.01 to 1 ______________________________________ and the concentration of each of the constituents (C) and (D) is zero.

Claim 12

A process for depositing an electrically insulating and corrosion resistant coating from an acidic hydrosol onto a substrate which consumes a minor quantity of acid from said hydrosol, said substrate being selected from the group consisting of metals higher than hydrogen in the electromotive series, porcelain, glass, wood, paper, cotton, plastics and hydrateable oxides, said process comprising forming an acidic hydrosol as defined in claim 1, contacting said hydrosol with said substrate to form a coating thereon and heating said coated substrate to dry said coating thereon.

Claim 13

The process of claim 11 wherein the substrate is silicon steel.

Claim 14

The process of claim 11 wherein the substrate is carbon steel.

Claim 15

The process of claim 11 wherein the substrate is aluminum.

Claim 16

The process of claim 11 wherein the substrate is porcelain.

Claim 17

The process of claim 11 wherein the substrate is glass.

Claim 18

The process of claim 11 wherein the substrate is wood.

Claim 19

The process of claim 11 wherein the substrate is paper.

Claim 20

The process of claim 11 wherein the substrate is cotton.

Claim 21

The process of claim 11 wherein the substrate is a synthetic resin.

Claim 22

The process of claim 11 wherein the substrate is silicon steel and the hydrosol is formed from the constituents water, phosphoric acid, sodium metasilicate, magnesium hydroxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium hydroxide 1 to 5 Boric oxide 0.02 to 1, ______________________________________ and the dried coating is thereafter annealed at a temperature of from about 1200° F. to about 1600° F.

Claim 23

The process of claim 11 wherein the substrate is silicon steel and the hydrosol is formed from the constituents water, phosphoric acid, and hydrous magnesium silicate in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 18. ______________________________________

Claim 24

The process of claim 11 wherein the substrate is silicon steel and the hydrosol is formed from the constituents water, phosphoric acid, hydrous magnesium silicate, magnesium oxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 5 Magnesium oxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 25

The process of claim 11 wherein the substrate is silicon steel and the hydrosol is formed from the constituents water, phosphoric acid, hydrous magnesium silicate, magnesium hydroxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 5 Magnesium hydroxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 26

The process of claim 11 wherein the substrate is aluminum and the hydrosol is formed from the constituents water, phosphoric acid, sodium metasilicate, magnesium oxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium oxide 1 to 5 Boric oxide 0.02 to 1, ______________________________________ and the dried coating is thereafter annealed at a temperature of about 1200° F.

Claim 27

The process of claim 11 wherein the substrate is aluminum and the hydrosol is formed from the constituents water, phosphoric acid, sodium metasilicate, magnesium hydroxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium hydroxide 1 to 5 Boric oxide 0.02 to 1, ______________________________________ and the dried coating is thereafter annealed at a temperature of about 1200° F.

Claim 28

The process of claim 11 wherein the substrate is aluminum and the hydrosol is formed from the constituents water, phosphoric acid, and the hydrous magnesium silicate in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 18. ______________________________________

Claim 29

The process of claim 11 wherein the substrate is aluminum and the hydrosol is formed from the constituents water, phosphoric acid, hydrous magnesium silicate, magnesium oxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 5 Magnesium oxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 30

The process of claim 11 wherein the substrate is aluminum and the hydrosol is formed from the constituents water, phosphoric acid, hydrous magnesium silicate, magnesium hydroxide and boric oxide in the following proportions: ______________________________________ Constituent Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 5 Magnesium hydroxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 31

A process for preparing an acidic hydrosol capable of depositing an electrically insulating and corrosion resistant coating onto a substrate which consumes a minor quantity of acid from said hydrosol, said substrate being selected from the group consisting of metals higher than hydrogen in the electromotive series, porcelain, glass, wood, paper, cotton, synthetic resins and hydrateable oxides, said process consisting essentially of admixing water with an acid selected from the group consisting of phosphoric acid, nitric acid, hydrochloric acid and acetic acid to form an aqueous acidic solution, and admixing with said solution until homogeneous a metal silicate selected from the group consisting of alkali metal metasilicates having the formula M 2 SiO 3 , alkali metal orthosilicates having the formula M 4 SiO 4 , where M is sodium or potassium, and hydrous magnesium silicate, a magnesium compound selected from the group consisting of magnesium oxide and magnesium hydroxide, and a boron compound selected from the group consisting of boric oxide and boric acid, wherein the proportions of said water, acid, metal silicate, magnesium compound and boron compound are as follows: ______________________________________ Percent by Weight ______________________________________ (A) Water About 43 to about 94 (B) Acid About 3 to about 51 (C) Alkali metal metasilicate 0 to about 16 (D) Alkai metal orthosilicate 0 to about 16 (E) Hydrous magnesium silicate 0 to about 18 (F) Magnesium compound 0 to about 6.6 (G) Boron compound 0 to about 1 ______________________________________ wherein : when (C) is zero, then (D) is at least 1% and (F) is at least 0.5%; when (D) is zero, then (C) is at least 1% and (F) is at least 0.5%; when both (C) and (D) are each zero, then (E) is at least about 0.9%; when both (C) and (E) are each zero, then (D) is at least 1% and (F) is at least 0.5%; when (D) and (E) are each zero, then (C) is at least 1% and (F) is at least 0.5%; when (C) is zero, then (D) is greater than zero but less than 1% when (E) is at least 0.9%; when (D) is zero, then (C) is greater than zero but less than 1% when (E) is at least 0.9%; the concentration of acid is at least the stoichiometric quantity required to react with either (C), (D) or (E), or with mixtures thereof to form silicic acid; and the ratio of M 2 O to SiO 2 is from about 1:1 to about 2:1 in said alkali metal metasilicates and orthosilicates.

Claim 32

A process for preparing an acidic hydrosol capable of depositing an electrically insulating and corrosion resistant coating onto a substrate which consumes a minor quantity of acid from said hydrosol, said substrate being selected from the group consisting of metals higher than hydrogen in the electromotive series, porcelain, glass, wood, paper, cotton, synthetic resins and hydrateable oxides, said process consisting essentially of admixing water with an acid selected from the group consisting of phosphoric acid, nitric acid, hydrochloric acid and acetic acid to form an aqueous acidic solution, and admixing with said solution until homogeneous a metal silicate selected from the group consisting of alkali metal metasilicates having the formula M 2 SiO 3 , alkali metal orthosilicates having the formula M 4 SiO 4 , where M is sodium or potassium, and hydrous magnesium silicate, a magnesium compound selected from the group consisting of magnesium oxide and magnesium hydroxide, and a boron compound selected from the group consisting of boric oxide and boric acid, wherein the proportions of said water, acid, metal silicate, magnesium compound and boron compound are as follows: ______________________________________ Percent by Weight ______________________________________ (A) Water About 43 to about 94 (B) Acid About 3 to about 51 (C) Alkali metal metasilicate 0 to about 16 (D) Alkai metal orthosilicate 0 to about 16 (E) Hydrous magnesium silicate 0 to about 18 (F) Magnesium compound 0 to about 6.6 (G) Boron compound 0 to about 1 ______________________________________ wherein : when (C) is zero, then (D) is at least 1% and (F) is at least 0.5%; when (D) is zero, then (C) is at least 1% and (F) is at least 0.5%; when both (C) and (D) are each zero, then (E) is at least about 0.9%; when both (C) and (E) are each zero, then (D) is at least 1% and (F) is at least 0.5%; when (D) and (E) are each zero, then (C) is at least 1% and (F) is at least 0.5%; when (C) is zero, then (D) is greater than zero but less than 1% when (E) is at least 0.9%; when (D) is zero, then (C) is greater than zero but less than 1% when (E) is at least 0.9%; the concentration of acid is at least the stoichiometric quantity required to react with either (C), (D) or (E), or with mixtures thereof to form silicic acid; and the ratio of M 2 O to SiO 2 is from about 1:1 to about 2:1 in said alkali metal metasilicates and orthosilicates.

Claim 33

The process of claim 30 wherein the substrate is silicon steel the acid is phosphoric acid, the metal silicate is sodium metasilicate, and the magnesium compound is magnesium hydroxide in the following proportions: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium hydroxide 1 to 5. ______________________________________

Claim 34

The process of claim 30 wherein the substrate is silicon steel, the acid is phosphoric acid, the metal silicate is sodium metasilicate and the magnesium compound is magnesium oxide in the following proportions: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium oxide 1 to 5. ______________________________________

Claim 35

The process of claim 30 wherein the substrate is silicon steel, the acid is phosphoric acid, the metal silicate is sodium metasilicate, the magnesium compound is magnesium hydroxide and the boron compound is boric oxide in the following proportions: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Sodium metasilicate 1 to 16 Magnesium hydroxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 36

The process of claim 30 wherein the substrate is silicon steel, the acid is phosphoric acid and the metal silicate is hydrous magnesium silicate in the following proportions: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 18. ______________________________________

Claim 37

The process of claim 30 wherein the substrate is silicon steel, the acid is phosphoric acid, the metal silicate is hydrous magnesium silicate, the magnesium compound is magnesium hydroxide and the boron compound is boric oxide in the following proportions: ______________________________________ Percent by Weight ______________________________________ Water 70 to 85 Phosphoric acid 10 to 20 Hydrous magnesium silicate 1 to 5 Magnesium hydroxide 1 to 5 Boric oxide 0.01 to 1. ______________________________________

Claim 38

A coated silicon steel sheet having thereon an adhered coating formed from the hydrosol defined in claim 1.