Liquid rinse conditioner for phosphate conversion coatings
AssigneePPG Industries, Inc.
InventorAngela Wright
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Abstract
The present invention relates to an improved titanium containing phosphate composition and a process for preparing the titanium containing phosphate composition. The composition in the form of a dilute aqueous dispersion is useful as a rinse conditioner for activating ferrous, zinc and aluminum metal surfaces prior to the application of phosphate conversion coatings. The rinse conditioner forms stable baths and can be used for activating metal surfaces for extended periods of time.
Claims36
A process for preparing a titanium containing phosphate composition which comprises:
- (a) mixing in an aqueous medium a sodium phosphate in amounts of 10 to 30 percent by weight with a titanium compound to form a mixture and heating said mixture to achieve a temperature of between about 65.degree. C. to about 95.degree. C. followed by
- (b) combining said mixture of (a) with a potassium phosphate in amounts of 20 to 40 percent by weight to form a concentrated aqueous dispersion of a titanium containing phosphate composition with titanium phosphate complex salts, wherein water is present in amounts of 30 to 60 percent by weight, wherein the percentages by weight are based on the total weight of ingredients which are used in the making of the titanium phosphate composition, and wherein the solids content is of at least 40 percent by weight based on weight of the concentrated aqueous dispersion.
A composition which when in aqueous solution is capable of activating ferrous, zinc or aluminum metal surfaces prior to the application of protective phosphate coatings which comprises a sodium phosphate, a potassium phosphate and titanium, in which the titanium is present as a complex salt with either or both of the sodium phosphate and the potassium phosphate, and the amount of sodium measured as sodium metal is from 6 to 14 percent by weight, based on solids weight of the composition;
- the amount of potassium measured as potassium metal is from 20 to 40 percent by weight, based on solids weight of the composition;
- the weight ratio of sodium to potassium measured as metals is 0.25 to 0.5:1;
- the amount of phosphorus measured as phosphorus metal is from 16 to 22 percent by weight, based on solids weight of the composition;
- and the titanium content measured as titanium metal is from 0.1 to 0.6 percent by weight, based on solids weight of the composition.
Dependencies are inferred from the claim text.