Method for treating feedwater

1. A method for treating feedwater comprising:

(a) introducing a treatment composition into feedwater to provide treated feedwater containing a carbonate scale inhibitor at a concentration of at least about 0.1 ppm before a detersive composition is added or introduced into the feedwater;

(b) combining the treated feedwater stream with the detersive composition to provide an use composition;

(c) delivering the use composition to a point of use; and

(d) contacting the use composition with an article, to inhibit carbonate scale including film on said article.

2. A method according to claim 1 , wherein the treated feedwater comprises the scale inhibitor at a concentration of about 0.1 ppm to about 200 ppm.

3. A method according to claim 1 , wherein the scale inhibitor comprises a mixture of at least one carbonate scale inhibitor and at least one phosphate scale inhibitor.

4. A method according to claim 3 , wherein the treated feedwater comprises about 1 ppm to about 100 ppm of a mixture of at least one carbonate scale inhibitor and at least one phosphate scale inhibitor.

5. A method according to claim 3 , wherein the at least one phosphate scale inhibitor comprises a polymer resulting from a reaction of an olefinically unsaturated carboxylic acid monomer and at least one of a copolymerizable sulfonated monomer, a copolymerizable nonionic monomer, or a mixture of at least one copolymerizable sulfonated monomer and at least one copolymerizable nonionic monomer.

6. A method according to claim 5 , wherein the olefinically unsaturated carboxylic acid monomer comprises a C 3 -C 40 monocarboxylic acid, a C 3 -C 40 dicarboxylic acid, or a C 3 -C 40 polycarboxylic acid.

7. A method according to claim 6 , wherein the olefinically unsaturated carboxylic acid monomer comprises an acid, a salt, or an anhydride.

8. A method according to claim 6 wherein the olefinically unsaturated carboxylic acid comprises acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloro-acrylic acid, alpha-cyano acrylic acid, beta methyl-acrylic acid, alpha phenylacrylic acid, beta-acryloxy propionic acid, sorbic acid, alpha-chloro sorbic acid, angelic acid, cinnamic acid, p-chloro cinnamic acid, beta styryl acrylic acid, itaconic acid, maleic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, fumaric acid or tricarboxyethylene, or mixtures thereof.

9. A method according to claim 6 , wherein the carboxylic monomer comprises monoolefinic acrylic acid having a substituent selected from hydrogen, halogen, hydroxyl, C 1 -C 20 alkyl, C 6 -C 12 aryl, C 6 -C 16 aralkyl, C 7 -C 16 alkaryl, C 5 -C 16 cycloaliphatic, or mixtures thereof.

10. A method according to claim 1 , wherein the scale inhibitor comprises at least one carbonate scale inhibitor further comprising at least one phosphonate, at least one polycarboxylate, or mixtures thereof.

11. A method according to claim 1 wherein the article comprises motor vehicle exterior, textile, food contacting article, clean-in-place (CIP) equipment, hard surface or mixture thereof.

12. A method according to claim 1 , wherein the scale inhibitor comprises a mixture of carbonate scale inhibitor and phosphate scale inhibitor at a weight ratio of the carbonate scale inhibitor to the phosphate scale inhibitor of about 1:1 to about 1:10.

13. A method according to claim 11 , further comprising:

(e) rinsing the use composition from the article.

14. A method according to claim 1 , wherein the detersive composition comprises a cleaning composition, a rinse agent composition, or a drying agent composition.