Use of block copolymers as dispersants for aqueous suspensions of solids
View Patent ↗The use of block copolymers which were prepared by polymerization of a poly(alkylene oxide) compound (A) with at least one ethylenically unsaturated monomer compound (B), as dispersants for aqueous suspensions of solids, in particular based on hydraulic binders, such as, for example, cement, lime, gypsum or anhydrite, is described. Surprisingly, these block copolymers have a substantially better water-reducing power at the same dose in comparison with conventional superplasticizers based on comb polymers. Moreover, the slump loss can also be reduced in comparison with conventional superplasticizers by modification of the adhesive block.
1. A method of dispersing aqueous suspensions of solids, the method comprising:
blending block copolymers with an aqueous suspension of solids, the suspension of solids including hydraulic binders which include materials selected from the group consisting of cement, lime, gypsum, anhydrite and mixtures thereof,
wherein the block copolymers are prepared by reacting a poly(alkylene oxide) compound of the general formula (I)
in which
R 1 =hydrogen, a C 1 —C 20 -alkyl radical, a cycloaliphatic C 5 —C 12 -cycloalkyl radical, an optionally substituted C 6 —C 14 -aryl radical;
m=2 to 4;
n=1 to 250;
and Z is selected from the group of formulas III, IV, and V
where Y═O or NR 2
R 2 =H,a C 1 —C 12 -alkyl radical, a C 6 —C 14 -aryl radical, or
X=Cl or Br
m′=1 to 4
n′=0 to 2,
where
R 3 =an optionally substituted C 6 —C 14 -arylene radical
X=Cl or Br,
in which
R 4 is H, a C 1 —C 12 alkyl radical, a C 5 —C 8 -cycloalkyl radical, a C 6 —C 14 -aryl radical, optionally substituted by hydroxyl, carboxyl or sulfo groups, or
and R 5 is C 1 —C 12 alkyl, C 6 —C 14 -aryl, or
and R 1 , R 2 , m and n have the abovementioned meaning,
with an ethylenically unsaturated monomer compound of the general formula (II) in a free radical, anionic or cationic polymerization
in which
R 6 and R 7 may be H, CH 3 , COOH or salts thereof, COOR 10 CONR 10
R 6 and R 9 together may be O—CO—O
R 8 may be H, CH 3 or —CH 2 —COOR 10
R 9 may be COOR 10 , an optionally substituted C 6 —C 14 -aryl radical or OR 11
R 10 may be H, C 1 —C 12 -alkyl, C 1 —C 12 -hydroxyalkyl,
R 11 may be acetyl, and
R 1 , m and n have the abovementioned meaning.
2. The method as claimed in claim 1 , wherein the reaction of the poly(alkylene oxide) compound with the monomer compound is carried out in the form of a free radical polymerization.
3. The method as claimed in claim 2 , wherein the reaction is effected in the form of an atom transfer radical polymerization.
4. The method as claimed in claim 1 , wherein the aryl radicals for R 1 are also substituted by hydroxyl, carboxyl and sulfo groups.
5. The method as claimed in claim 1 , wherein in formula (I), m is 2 or 3 and n is 5 to 250.
6. The method as claimed in claim 1 , wherein R 2 is hydrogen or C 1 —C 2 -alkyl radical.
7. The method as claimed in claim 1 , wherein m′ is 1 and n′ is 0 or 1.
8. The method as claimed in claim 1 , wherein the arylene radical R 3 also has halo, hydroxyl, C—C 12 -alkoxy, C 1 —C 12 - dialkylamino or carboxyl groups.
9. The method as claimed in claim 1 , wherein R 6 and R 7 are H,R 6 and R 9 together are O—CO—O, R 8 is H,CH 3 or CH 2 COOR 10 and R 9 is COOR 10 or is a phenyl radical optionally substituted by hydroxyl, carboxyl or sulfo groups.
10. The method as claimed in claim 9 , wherein R 6 and R 7 are H, R 8 =H or CH 3 and R 9 =COOR 10 .
11. The method as claimed in claim 10 , wherein R 6 and R 7 are H,R 8 =H or CH 3 and R 9 is COOH or salts thereof or COOR 12 where R 12 is tert-butyl or C 1 —C 6 -hydroxyalkyl.
12. The method as claimed in claim 1 , wherein the reaction of the poly (alkylene oxide) compound and the monomer compound is carried out in the presence of a inimer compound.
13. The method as claimed in claim 12 , wherein the inimer compound is prepared by esterification of hydroxy-functionalized monomers with ATRP initiators.
14. The method as claimed in claim 12 , wherein the inimer compound is prepared by sulfochlorination of styrene.
15. The method as claimed in claim 1 , wherein the reaction is effected in the temperature range from 20 to 110° C.
16. The method as claimed in claim 1 , wherein the block copolymers are used in an amount of 0.01 to 5% by weight, based on the suspension of solids.
17. The method as claimed in claim 16 , wherein the suspension of solids further includes inorganic particles selected from the group consisting of crushed rock, silicate powder, chalk, clays, porcelain slip, talc, pigments and carbon black.
18. The method as claimed in claim 16 , wherein the suspension of solids contains organic particles.
19. A method of superplasticizing aqueous suspensions of solids, the method comprising:
blending block copolymers with an aqueous suspension of solids to superplasticize the suspension of solids, the suspension of solids including hydraulic binders which include materials selected from the group consisting of cement, lime, gypsum, anhydrite and mixtures thereof,
wherein the block copolymers are prepared by reacting a poly(alkylene oxide) compound of the general formula (I)
in which
R 1 =hydrogen, a C 1 —C 20 -alkyl radical, a cycloaliphatic C 5 —C 12 -cycloalkyl radical, an optionally substituted C 6 —C 14 -aryl radical;
m=2 to 4;
n=1 to 250;
and Z is selected from the group of formulas III, IV, and V
where Y=0 or NR 2
R 2 =H, a C 1 —C 12 -alkyl radical, a C 6 —C 14 -aryl radical, or
X=Cl or Br
m′=1 to 4
n′=0 to 2,
where
R 3 =an optionally substituted C 6 —C 14 -arylene radical
X=Cl or Br,
in which
R 4 is H, a C 1 —C 12 alkyl radical, a C 5 —C 8 -cycloalkyl radical, a C 6 —C 14 -aryl radical, optionally substituted by hydroxyl, carboxyl or sulfo groups, or
and R 5 is C 1 —C 12 alkyl, C 6 —C 14 -aryl, or
and R 1 , R 2 ,m and n have the abovementioned meaning, with an ethylenically unsaturated monomer compound of the general formula (II) in a free radical, anionic or cationic polymerization
in which
R 6 and R 7 may be H, CH 3 ,COOH or salts thereof, COOR 10 , CONR 10 R 10
R 6 and R 9 together may be O—CO—O
R 8 may be H, CH 3 or —CH 2 —COOR 10
R 10 may be COOR 10 ,an optionally substituted C 6 —C 14 -aryl radical or OR 11
R 10 may be H, C 1 —C 12 -alkyl, C 1 —C 12 -hydroxyalkyl,
R 11 may be acetyl, and
R 1 , m and n have the abovementioned meaning.
20. The method as claimed in claim 19 , wherein the reaction of the poly(alkylene oxide) compound with the monomer compound is carried out in the form of a free radical polymerization.
21. The method as claimed in claim 20 , wherein the reaction is effected in the form of an atom transfer radical polymerization.
22. The method as claimed in claim 19 , wherein the aryl radicals for R 1 are also substituted by hydroxyl, carboxyl and sulfo groups.
23. The method as claimed in claim 19 , wherein in formula (I), m is 2 or 3 and n is 5 to 250.
24. The method as claimed in claim 19 , wherein that R 2 is hydrogen or C 1 —C 2 -alkyl radical.
25. The method as claimed in claim 19 , wherein m′ is 1and n′ is 0 or 1.
26. The method as claimed in claim 19 , wherein the arylene radical R 3 also has halo, hydroxyl, C 1 —C 12 -alkoxy, C 1 —C 12 -dialkylamino or carboxyl groups.
27. The method as claimed in claim 19 , wherein R 6 and R 7 are H,R 6 and R 9 together are O—CO—O, R 8 is H, CH 3 or CH 2 COOR 10 and R 9 is COOR 10 or is a phenyl radical optionally substituted by hydroxyl, carboxyl or sulfo groups.
28. The method as claimed in claim 27 , wherein R 6 and R 7 are H,R 8 =H or CH 3 and R 9 =COOR 10 .
29. The method as claimed in claim 28 , wherein R 6 and R 7 are H,R 8 =H or CH 3 and R 9 is COOH or salts thereof or COOR 12 ,where R 12 is tert-butyl or C 1 —C 6 -hydroxyalkyl.
30. The method as claimed in claim 19 , wherein the reaction of the poly (alkylene oxide) compound and the monomer compound is carried out in the presence of a inimer compound.
31. The method as claimed in claim 30 , wherein the inimer compound is prepared by esterification of hydroxy-functionalized monomers with ATRP initiators.
32. The method as claimed in claim 30 , wherein the inimer compound is prepared by sulfochlorination of styrene.
33. The method as claimed in claim 19 , wherein the reaction is effected in the temperature range from 20 to 110° C.
34. The method as claimed in claim 19 , wherein the block copolymers are used in an amount of 0.01 to 5% by weight, based on the suspension of solids.
35. The method as claimed in claim 34 , wherein the suspension of solids further includes inorganic particles selected from the group consisting of crushed rock, silicate powder, chalk, clays, porcelain slip, talc, pigments and carbon black.
36. The method as claimed in claim 34 , wherein the suspension of solids contains organic particles.