Abstract The process for the production of a protectively coated metal object which comprises applying to said metal object at least one condensable phosphate selected from the group consisting of alkali metal hydrogen phosphates and alkali metal ammonium phosphates and thereafter heating said object to a temperature above about 400*C whereby said phosphate undergoes condensation to produce a glass-like protective coating. The metal object, which may be bright or freshly surface-oxidized, is preferably iron or an iron alloy and the phosphate preferably is of the formula MenX2PnO(3n 1) IN WHICH EACH X is a hydrogen or ammonium ion, N IS AN INTEGER, Me is an alkali metal ion which, when n is 4 or more, may be partially replaced by a hydrogen, ammonium or equivalent of a polyvalent metal ion.
Inventors
👤 Joachim Marx
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-09 06:06
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/73; C23C22/74
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
31 words
THE PROCESS FOR THE PRODUCTION OF A PROTECTIVELY COATED METAL OBJECT WHICH COMPRISES APPLYING TO SAID METAL OBJECT A MATERIAL CONSISTING ESSENTIALLY OF AT LEAST ONE CONDENSABLE PHOSPHATE OF THE FORMULA
Claim 2
Dependent Claim
31 words
THE PROCESS FOR THE PRODUCTION OF A PROTECTIVELY COATED METAL OBJECT WHICH COMPRISES APPLYING TO SAID METAL OBJECT A MATERIAL CONSISTING ESSENTIALLY OF AT LEAST ONE CONDENSABLE PHOSPHATE OF THE FORMULA
Claim 3
Dependent Claim
15 words
The process of claim 1, wherein said metal object comprises iron or an iron alloy.
Claim 4
Dependent Claim
20 words
The process of claim 1, wherein said metal object has a temperature above about 400*C during application of said phosphate.
Claim 5
Dependent Claim
10 words
The process of claim 1, in which X is hydrogen.
Claim 6
Dependent Claim
13 words
The process of claim 4, in which n is 4 to about 15.
Claim 7
Dependent Claim
16 words
The process of claim 1, in which Me is at least one of sodium and potassium.
Claim 8
Dependent Claim
20 words
The process of claim 6, in which Me is sodium and potassium in the approximate molar ratio of K:Na 7-1:1.
Claim 9
Dependent Claim
13 words
The process of claim 1, in which at least one Me is hydrogen.
Claim 10
Dependent Claim
24 words
The process of claim 1, wherein the condensable phosphate is an acid polyphosphate with a P2O5 content of at least about 83% by weight.
Claim 11
Dependent Claim
26 words
The process of claim 9, wherein the acid polyphosphate is employed in aqueous solution which has been neutralized to a pH of at least about 2.5.
Claim 12
Dependent Claim
20 words
The process of claim 10, wherein an alkali metal metaphosphate is added to the aqueous solution as a thickening agent.