Phosphate conversion coating and compositions and concentrates therefor with stable internal accelerator
AssigneeHenkel Corporation
InventorsRobert W. Miller, Michael Petschel
Life of this patent
Estimating the term…
Abstract
The following water soluble materials are all satisfactory internal accelerators for otherwise conventional zinc phosphate conversion coating solutions: reducing sugars, starch, urea, and poly{acrylates and methacrylates}. Concentrates including these ingredients and otherwise conventional constituents of zinc phosphate conversion coating compositions, except for excluding conventional accelerators other than nitrate, are stable in composition during storage, unlike most conversion coating compositions containing conventional accelerators. Thus concentrates according to the invention are practical single-package concentrates that can be made into working phosphating compositions by dilution with water only.
Claims20
An aqueous liquid make-up concentrate composition suitable for dilution with water to form a working phosphate conversion coating composition, said concentrate composition consisting essentially of water and the following dissolved components wherein amounts are based on the total composition:
- (A) from about 150 to about 825 g/kg of phosphate ions;
- (B) zinc cations in such an amount that the ratio of phosphate ions to zinc ions is within the range from about 3:1 to about 100:1;
- (C) at least one of:
- (C.1) from about 0.10 to about 300 g/kg of internal accelerator selected from the group consisting of reducing sugars, starch, and urea;
- (C.2) from about 0.0005 to about 1.0 g/kg of acrylate or methacrylate polymers;
- and
- (D) an amount of acid such that a solution of 6.0% of the concentrate in deionized water will have from about 1.0 to about 40 points of free acid and from about 3.5 to 70 points of total acid;
- and, optionally,
- (E) an amount of manganese (II) cations such that the ratio of the manganese cations to the zinc cations is within the range from about 1:10 to 5:1;
- and, optionally,
- (F) at least one of:
- (F.1) an amount of divalent cations selected from the group consisting of nickel, cobalt, and magnesium cations such that the ratio of the total of these divalent cations to the zinc cations is within the range from about 1:5 to 5:1;
- (F.2) an amount of divalent copper cations such that the ratio of the copper cations to the zinc cations is within the range from about 0.0025:5 to about 0.5:1;
- and, optionally,
- (G) from about 1.0 to about 50 g/kg of complex fluoride ions;
- and, optionally,
- (H) from about 0.4 to about 20 g/kg of fluoride ions derived from the group consisting of hydrofluoric acid and alkali metal and ammonium fluorides and bifluorides;
- and, optionally,
- (J) not more than 200 g/kg of nitrate ions.
An aqueous liquid replenisher concentrate composition, said concentrate composition consisting essentially of water and the following dissolved components wherein amounts are based on the total composition:
- (A) from about 150 to about 825 g/kg of phosphate ions;
- (B) zinc cations in such an amount that the ratio of phosphate ions to zinc ions is within the range from about 1:1 to about 35:1;
- (C) at least one of:
- (C.1) from about 0.10 to about 300 g/kg of internal accelerator selected from the group consisting of reducing sugars, starch, and urea;
- (C.2) from about 0.0005 to about 1.0 g/kg of acrylate or methacrylate polymers;
- and
- (D) an amount of acid such that a solution of 6.0% of the concentrate in deionized water will have from about 1.0 to about 10 points of free acid and from about 3.5 to 70 points of total acid;
- and, optionally,
- (E) an amount of manganese (II) cations such that the ratio of the manganese cations to the zinc cations is within the range from about 1:10 to 2:1;
- and, optionally,
- (F) at least one of:
- (F.1) an amount of divalent cations selected from the group consisting of nickel, cobalt, and magnesium cations such that the ratio of the total of these divalent cations to the zinc cations is within the range from about 0.05:1 to 1.5:1;
- (F.2) an amount of divalent copper cations such that the ratio of the copper cations to the zinc cations is within the range from about 0.0025:5 to about 0.5:1;
- and, optionally,
- (G) from about 1.0 to about 50 g/kg of complex fluoride ions;
- and, optionally,
- (H) from about 0.4 to about 20 g/kg of fluoride ions derived from the group consisting of hydrofluoric acid and alkali metal and ammonium fluorides and bifluorides;
- and, optionally,
- (J) not more than 200 g/kg of nitrate ions.
Dependencies are inferred from the claim text.