Method of controlling scale in aqueous systems

1. A quaternized fluorescent monomer comprising the structure:

wherein

R 4 is selected from H, hydroxy, alkoxy or C 1 -C 4 alk-O—(CHR 5 CH 2 O—)n;

R 5 is selected from H and C 1 -C 4 -alkyl;

n is 1-10; and

X − is an anionic counter ion;

and comprising less than 8 mol%, based on 100 mol% of total naphthalimide fluorescent monomer of the structure:

wherein R 4 is as defined above.

2. The quaternized fluorescent monomer of claim 1 , which comprises the structure:

wherein X − is an anionic counter ion;

and comprises less than 8 mol%, based on 100 mol% of total naphthalimide fluorescent monomer of the structure:

3. The quaternized fluorescent monomer of claim 2 , wherein X − is an anionic counterion selected from the group consisting of chloride, bromide, hydroxide, methosulphate, sulfate, sulfonate, carboxylate, phosphate, and phosphonate.

4. The quaternized fluorescent monomer of claim 1 , wherein X − is an anionic counterion selected from the group consisting of chloride, bromide, hydroxide, methosulphate, sulfate, sulfonate, carboxylate, phosphate, and phosphonate.

5. The quaternized fluorescent monomer of claim 1 , which comprises (a) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, 2-hydroxy-3-(meth)allyloxypropyl quaternary salt comprising less than 5 mol% of (b) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, based on 100 mol% of (a).

6. A polymer prepared by polymerizing the quaternized fluorescent monomer of claim 5 with other monomers.

7. The quaternized fluorescent monomer of claim 1 , which comprises (a) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, 2-hydroxy-3-(meth)allyloxypropyl quaternary salt comprising less than 1.5 mol% of (b) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, based on 100 mol% of (a).

8. A polymer prepared by polymerizing the quaternized fluorescent monomer of claim 7 with other monomers.

9. A polymer prepared by polymerizing the quaternized fluorescent monomer of claim 1 with other monomers.

10. The polymer according to claim 9 , wherein the other monomers are selected from the group consisting of cationic, anionic, and/or nonionic monomers.

11. The polymer according to claim 10 , wherein the quaternized fluorescent monomer is incorporated into the polymer to an extent equal to or greater than 90 mol%.

12. The polymer according to claim 10 , wherein the quaternized fluorescent monomer is incorporated into the polymer to an extent equal to or greater than 95 mol%.

13. A water treatment polymer formed from polymerizing a polymerization mixture comprising:

(i) at least one water-soluble carboxylic acid monomer, or salt or anhydride thereof, present in an amount of 10-99.999 mol% based on 100 mol% of the polymer;

(ii) the quaternized fluorescent monomer of claim 1 ; and

wherein the polymer chains of the water treatment polymer formed comprise 0.001 mol% to less than or equal to 10 mol% of the quaternized fluorescent monomer of claim 1 as unreacted monomer unincorporated into the polymer chains thereby indicating that said quaternized fluorescent monomer of claim 1 has been incorporated into said water treatment polymer to an extent equal to or greater than 90 mol%.

14. The polymer of claim 13 , wherein said quaternized fluorescent monomer is incorporated into the polymer to the extent of at least 95 mol%.

15. The polymer of claim 13 , wherein the polymerization mixture comprises (a) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, 2-hydroxy-3-(meth)allyloxypropyl quaternary salt comprising less than 5 mol% of (b) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, based on 100 mol% of (a).

16. The polymer of claim 15 , wherein (a) is incorporated into the polymer to the extent of at least 95 mol%.

17. The polymer of claim 13 , wherein the polymerization mixture comprises (a) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, 2-hydroxy-3-(meth)allyloxypropyl quaternary salt comprising less than 1.5 mol% of (b) N-(3-dimethylaminopropyl)-4-methoxy-1,8-naphthalimide, based on 100 mol% of (a).

18. The polymer of claim 17 , wherein (a) is incorporated into the polymer to the extent of at least 98 mol%.

19. A process of preparing a water treatment polymer, the process comprising the following steps:

(a) polymerizing a polymerization mixture comprising:

(i) at least one water-soluble carboxylic acid monomer, or salt or anhydride thereof, present in an amount of 10-99.999 mol% based on 100 mol% of the polymer;

(ii) the quaternized fluorescent monomer of claim 1 ; and

(b) wherein the polymer chains of the water treatment polymer formed comprise 0.001 mol% to less than or equal to 10 mol% of the quaternized fluorescent monomer of claim 1 as unreacted monomer unincorporated into the polymer chains thereby indicating that said quaternized fluorescent monomer of claim 1 has been incorporated into said water treatment polymer to an extent equal to or greater than 90 mol%.

20. A method of controlling scale in a water system, the method comprising the steps of:

(a) dosing the water system with a water treatment polymer according to claim 13 ; and

(b) monitoring the fluorescent signal emitted from said water system.

21. A method for coagulation or flocculation in a water treatment system, the method comprising the steps of:

(a) dosing the water treatment system with the water treatment polymer according to claim 13 ; and

(b) monitoring the fluorescent signal emitted from the water treatment system.

22. A method for determining whether a given location has been cleaned comprising the steps of:

(a) applying the water treatment polymer according to claim 13 to the location;

(b) cleaning the location at least once; and

(c) measuring fluorescence at the location after said cleaning, which, presence, if detected, indicates that additional cleaning is needed.

23. A method of controlling scale in a water system, the method comprising the steps of:

(a) dosing the water system with a water treatment polymer according to claim 9 ; and

(b) monitoring the fluorescent signal emitted from said water system.

24. A method for coagulation or flocculation in a water treatment system, the method comprising the steps of:

(a) dosing the water treatment system with the water treatment polymer according to claim 9 ; and

(b) monitoring the fluorescent signal emitted from the water treatment system.

25. A method for determining whether a given location has been cleaned comprising the steps of:

(a) applying the water treatment polymer according to claim 9 to the location;

(b) cleaning the location at least once; and

(c) measuring fluorescence at the location after said cleaning, which, presence, if detected, indicates that additional cleaning is needed.