Note : Les revendications sont présentées dans la langue officielle dans laquelle elles ont été soumises.
- 14 -
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of treating an aqueous system which
comprises adding thereto a water soluble zinc salt, a chelant
which possesses the formula:
Image
wherein R1 is hydrogen, hydroxyethyl or carboxymethyl, R2 is
hydrogen, hydroxyphenyl, which is optionally methyl or
sulfonic acid substituted, or carboxyl, R4 is hydrogen or
carboxyl, R3 is
Image, -CH2CH2OH, - CH2C6H3(OH) (SO3H) or
Image
wherein R1, R2 and R4 are as above defined and X is -(CH2)2- or
-(CH2)3-, the phenyl groups being optionally further
substituted by one or more halogen atoms with the proviso that
at least one of R2 and R3 contains a hydroxyphenyl group and
either a product containing at least one carboxylic acid group
or an acrylic, vinyl or allyl carboxylic acid polymer.
- 14(a) -
2. A method according to Claim 1 in which the
chelant possesses the formula
Image
where R1 is hydrogen, hydroxyethyl or carboxymethyl, R2 is
hydrogen, hydroxyphenyl, which is optionally methyl or
sulphonic acid substituted, or carboxyl, R4 is hydrogen or
carboxyl, R3 is Image, -CH2CH2OH,
-CH2C6H3(OH)(SO3H) or Image
wherein R1, R2 and R4 are as defined above and X is
-(CH2)2- or -(CH2)3-; the phenyl groups being otionally
further substituted by one or more halogen atoms.
3. A method according to Claim 2 in which 1 to 10
parts by weight of chelant are added per part by weight of
zinc salt.
4. A method according to Claim 3 in which 4 to 6
parts by weight of the phosphorus-containing compound are
added per part by weight of the zinc salt.
- 15 -
5. A method according to Claim 2, 3 or 4 in which
the zinc salt is zinc sulphate, zinc chloride, zinc
nitrate or zinc acetate.
6. A method according to Claim 2, 3 or 4 in which
the phosphonate has the general formula
Image
wherein R is hydrogen, alkyl, alkenyl or alkynyl having up
to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon
atoms; benzyl; phenethyl or
Image
wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms
or carboxyl, R" is hydrogen or methyl and R''' is carboxyl
or phosphonate.
7. A method according to Claim 2, 3 or 4 in which
the phosphonate is hydroxy-phosphonoacetic acid or
2-phosphonobutane-1,2,4-tricarboxylic acid.
8. A method according to Claim 2, 3 or 4 in which
the product containing at least one phosphorus-containing
acid group and at least one carboxylic acid group is a
phosphino polycarboxylic acid having the formula
Image
where N + M = 4 to 20.
- 16 -
9. A method according to Claim 1, 2 or 3 in which
the polymer is a copolymer of acrylic, methacrylic,
maleic, fumaric, itaconic, crotonic or cinnamic acid with
acrylamide, an acrylate or methacrylate ester or hydroxy
ester, vinyl pyrrolidone, vinyl acetate, acrylonitrile,
vinyl methyl ether, 2-acrylamido-2-methyl-propane
sulphonic acid, vinyl, allyl or styrene sulphonic acid, or
diallyldimethyl ammonium chloride or dimethylamino ethyl
acrylate or methacrylate, optionally quaternised with
dimethyl sulphate or methyl chloride.
10. A method according to Claim 1, 2 or 3 in which
the polymer is a polymer of acrylic acid, methacrylic
acid, maleic acid, fumaric acid, itaconic acid or crotonic
acid, having a molecular weight from 1000 to 5000.
11. A method according to Claim 2, 3 or 4 in which
the zinc salt is added in an amount to provide up to 5 ppm
zinc.
12. A method according to Claim 2, 3 or 4 in which
the zinc salt is added to provide up to 2 ppm zinc.
13. A method according to Claim 2, 3 or 4 in which
the system water attains a temperature of at least 40°C.
14. A method according to Claim 2, 3 or 4 in which
the system water attains a pH of 8.2.
15. A method according to Claim 1 in which the
chelant is N,N'-di(2-hydroxyethyl) glycine.
16. A method according to Claim 1 or Claim 15 in
which the zinc salt is zinc sulphate, zinc chloride, zinc
nitrate or zinc acetate.
- 17 -
17. A method according to Claim 1 in which the
chelant is N,N'-di(2-hydroxybenzyl)-trimethylenediamine-
N,N'-diacetic acid, N,N'-ethylenebis-[2-(2-hydroxy-4-
methyl-phenyl)-glycine], ethylenediamine N,N'-bis-[2-
hydroxyphenylacetic acid] or N,N-di(2-hydroxy-5-sulphonic
acid benzyl) glycine.
18. A method according to Claim 17 in which 1 to 10
parts by weight of chelant are added per part by weight of
zinc salt.
19. A method according to Claim 18 in which the zinc
salt is zinc chloride, zinc nitrate or zinc acetate.
20. A method according to Claim 17, 18 or 19 in
which 4 to 6 parts by weight of the phosphorus-containing
compound are added per part by weight of the zinc salt.
21. A method according to Claim 15, 17 or 18 in
which the phosphonate has the general formula
Image
wherein R is hydrogen, alkyl, alkenyl or alkynyl having up
to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon
atoms; benzyl; phenethyl or
Image
wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms
or carboxyl, R" is hydrogen or methyl and R''' is carboxyl
or phosphonate.
- 18 -
22 A method according to Claim 15, 17 or 18 in
which the phosphonate is hydroxy-phosphonoacetic acid or
2-phosphonobutane-1,2,4-tricarboxylic acid.
23. A method according to Claim 15, 17 or 18 in
which the product containing at least one phosphorus-
containing acid group and at least one carboxylic acid
group is a phosphino polycarboxylic acid having the
formula
Image
where N + M = 4 to 20.
24. A method according to Claim 15, 17 or 18 in
which the polymer is a copolymer of acrylic, methacrylic,
maleic, fumaric, itaconic, crotonic or cinnamic acid with
acrylamide, an acrylate or methacrylate ester or hydroxy
ester, vinyl pyrrolidone, vinyl acetate, acrylonitrile,
vinyl methyl ether, 2-acrylamido-2-methyl-propane
sulphonic acid, vinyl, allyl or styrene sulphonic acid, or
diallyldimethyl ammonium chloxide or dimethylamino ethyl
acrylate or methacrylate, optionally quaternised with
dimethyl sulphate or methyl chloride.
25. A method according to Claim 15, 17 or 18 in
which the polymer is a polymer of acrylic acid,
methacrylic acid, maleic acid, fumaric acid, itaconic acid
or crotonic acid, having a molecular weight from 1000 to
5000.
26. A method according to Claim 15, 17 or 18 in
which the zinc salt is added in an amount to provide up to
5 ppm zinc.
- 19 -
27. A method according to Claim 15, 17 or 18 in
which the zinc salt is added to provide up to 2 ppm zinc.
28. A method according to Claim 15, 17 or 18 in
which the system water attains a temperature of at least
40°C.
29. A method according to Claim 15, 17 or 18 in
which the system water attains a pH of 8.2.
30. A method according to Claim 1, 3 or 18 in which
the product containing at least one phosphorus-containing
acid group is a phosphonate containing at least two acid
groups one of which is a phosphonate and the other is a
carboxylic acid group, at least the two said acid groups
being attached to carbon atoms.
31. A composition suitable for addition to an
aqueous system which comprises a water-soluble zinc salt,
a chelant, and a product containing at least one
phosphorus-containing acid group and at least one
carboxylic acid group or an acrylic, vinyl or allyl
carboxylic acid polymer.
32. A composition according to Claim 31 in which the
chelant possesses the formula
Image
wherein R1 is hydrogen, hydroxyethyl or carboxymethyl, R2
is hydrogen, hydroxyphenyl, which is optionally methyl or
-20-
sulphonic acid substituted, or carboxyl, R4 is hydrogen or
carboxyl, R3 is Image, -CH2CH2OH,
-CH2C6H3(OH)(SO3H) or Image
wherein R1, R2 and R3 are as defined above and X is
-(CH2)2- or -(CH2)3-; the phenyl groups being otionally
further substituted by one or more halogen atoms.
33. A composition according to Claim 32 which
contains 1 to 10 parts by weight of chelant per part by
weight of zinc salt.
34. A composition according to Claim 33 which
contains 4 to 6 parts by weight of the phosphorus-
containing compound per part by weight of the zinc salt.
35. A composition according to Claim 32, 33 or 34 in
which the zinc salt is zinc sulphate, zinc chloride, zinc
nitrate or zinc acetate.
36. A composition according to Claim 32, 33 or 34 in
which the phosphonate has the general formula
Image
wherein R is hydrogen, alkyl, alkenyl or alkynyl having up
to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon
atoms; benzyl; phenethyl or
Image
-21-
wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms
or carboxyl, R" is hydrogen or methyl and R''' is carboxyl
or phosphonate.
37. A composition according to Claim 32, 33 or 34 in
which the phosphonate is hydroxy-phosphonoacetic acid or
2-phosphonobutane-1,2,4-tricarboxylic acid.
38. A composition according to Claim 32, 33 or 34 in
which the product containing at least one phosphorus-
containing acid group and at least one carboxylic acid
group is a phosphino polycarboxylic acid having the
formula
Image
where N + M = 4 to 20.
39. A composition according to Claim 31, 32 or 33 in
which the polymer is a copolymer of acrylic, methacrylic,
maleic, fumaric, itaconic, crotonic or cinnamic acid with
acrylamide, an acrylate or methacrylate ester or hydroxy
ester, vinyl pyrrolidone, vinyl acetate, acrylonitrile,
vinyl methyl ether, 2-acrylamido-2-methyl-propane
sulphonic acid, vinyl, allyl or styrene sulphonic acid, or
diallyldimethyl ammonium chloride or dimethylamino ethyl
acrylate or methacrylate, optionally quaternised with
dimethyl sulphate or methyl chloride.
40. A composition according to Claim 31, 32 or 33 in
which the polymer is a polymer of acrylic acid, metha-
crylic acid, maleic acid, fumaric acid, itaconic acid or
crotonic acid, having a molecular weight from 1000 to
5000.
-22-
41. A composition according to Claim 31, 32 or 33
which is aqueous.
42. A composition according to Claim 31, 32 or 33
which is aqueous and contains from 1 to 2 percent by
weight of zinc salt (as zinc), from 4 to 10 percent by
weight of the phosphorus and carboxylic acid group-
containing material or polymer and from 1 to 25 percent by
weight of the chelant.
43. A composition according to Claim 31, 32 or 33
which further comprises a phosphate, biocide, yellow metal
corrosion inhibitor or dispersant.
44. A composition according to Claim 31, 32 or 33
which further comprises a dispersant which is a copolymer
of methacrylic acid and acrylamide.
45. A composition according to Claim 31 in which the
chelant is N,N'-di(2-hydroxyethyl) glycine.
46. A composition according to Claim 45 which
contains 1 to 10 percent by weight of chelant per part by
weight of zinc salt.
47. A composition according to Claim 31 in which the
chelant is N,N'-di(2-hydroxybenzyl)-trimethylenediamine-
N,N'-diacetic acid, N,N'-ethylenebis-[2-(2-hydroxy-4-
methyl-phenyl)-glycine], ethylenediamine N,N'-bis-[2-
hydroxyphenylacetic acid] or N,N-di(2-hydroxy-5-sulphonic
acid benzyl) glycine.
48. A composition according to Claim 47 which
contains 1 to 10 parts by weight of chelant per part by
weight of zinc salt.
-23-
49. A composition according to Claim 1, 46 or 48 in which
the zinc salt is zinc chloride, zinc nitrate or zinc
acetate.
50. A composition according to Claim 46, 47 or 48
which contains 4 to 6 parts by weight of the phosphorus-
containing compound per part by weight of the zinc salt.
51. A composition according to Claim 45, 47 or 48 in
which the phosphonate has the general formula
Image
wherein R is hydrogen, alkyl, alkenyl or alkynyl having up
to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon
atoms; benzyl; phenethyl or
Image
wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms
or carboxyl, R" is hydrogen or methyl and R''' is carboxyl
or phosphonate.
52. A composition according to Claim 45, 47 or 48 in
which the phosphonate is hydroxy-phosphonoacetic acid or
2-phosphonobutane-1,2,4-tricarboxylic acid.
53. A composition according to Claim 45, 47 or 48 in
which the product containing at least one phosphorus-
containing acid group and at least one carboxylic acid
-24-
group is a phosphino polycarboxylic acid having the
formula
Image
where N + M = 4 to 20.
54. A composition according to Claim 45, 47 or 48 in
which the polymer is a copolymer of acrylic, methacrylic,
maleic, fumaric, itaconic, crotonic or cinnamic acid with
acrylamide, an acrylate or methacrylate ester or hydroxy
ester, vinyl pyrrolidone, vinyl acetate, acrylonitrile,
vinyl methyl ether, 2-acrylamido-2 methyl-propane
sulphonic acid, vinyl, allyl or styrene sulphonic acid, or
diallyldimethyl ammonium chloride or dimethylamino ethyl
acrylate or methacrylate, optionally quaternised with
dimethyl sulphate or methyl chloride.
55. A composition according to Claim 45, 47 or 48 in
which the polymer is a polymer of acrylic acid,
methacrylic acid, maleic acid, fumaric acid, itaconic acid
or crotonic acid, having a molecular weight from 1000 to
5000.
56. A composition according to Claim 45, 47 or 48
which is aqueous.
57. A composition according to Claim 45, 47 or 48
which is aqueous and contains from 1 to 2 percent by
weight of zinc salt (as zinc), from 4 to 10 percent by
weight of the phosphorus and carboxylic acid group-
containing material or polymer and from 1 to 25 percent by
weight of the chelant.
-25-
58. A composition according to Claim 45, 47 or 48
which further comprises a phosphate, biocide, yellow metal
corrosion inhibitor or dispersant.
59. A composition according to Claim 45, 47 or 48
which further comprises a dispersant which is a copolymer
of methacrylic acid and acrylamide.
60. A composition according to Claim 33, 46 or 48 in
which the product containing at least one phosphorous-
containing acid group is a phosphonate containing at least
two acid groups one of which is a phosphonate and the
other is a carboxylic acid group, at least the two said
acid groups being attached to carbon atoms.