Silica-based sols
View Patent ↗The invention relates to a sol containing silica-based particles having an axial ratio of at least about 10 and specific surface area of at least about 600 m2/g. The invention further relates to a sol containing silica-based particles having an axial ratio of at least about 10 and S-value up to about 25. The invention further relates to a sol containing silica-based particles having an axial ratio of at least about 10 and a specific surface area of at least about 400 m2/g, wherein the silica-based particles are surface-modified. The invention further relates to a sol containing silica-based particles having a viscosity of at least 50 cP and silica content of at least about 3% by weight, wherein the silica-based particles have a specific surface area of at least about 400 m2/g. The invention further relates to a process for producing the aqueous silica-based sol according to the invention, a sol containing silica-based particles obtainable by the process, use of the sol containing silica-based particles as a flocculating agent. The invention further relates to a process for producing paper in which the sol containing silica-based particles is used as a drainage and retention aid.
1. Sol containing silica-based particles having an axial ratio in the range of from about 10 to about 100 and specific surface area of at least about 600 m 2 /g, wherein the sol is modified with aluminum.
2. Sol containing silica-based particles having an axial ratio of at least about 10 and S-value up to about 25%.
3. The sol according to claim 1 , wherein the axial ratio is in the range of from 10 to 50.
4. The sol according to claim 3 , wherein the axial ratio is in the range of from 11 to 35.
5. The sol according to claim 1 , wherein the silica-based particles have a specific surface area in the range of from 800 to 1600 m 2 /g.
6. The sol according to claim 1 , wherein the silica-based particles have a specific surface area of at least about 1000 m 2 /g.
7. The sol according to claim 1 , wherein the silica-based particles are surface-modified with aluminum.
8. The sol according to claim 1 , wherein the sol has a silica content of at least about 3% by weight.
9. The sol according to claim 1 , wherein the sol has an S-value in the range of from about 5 to about 20%.
10. The sol according to claim 1 , wherein the sol has a pH in the range of from about 7.0 to about 10.0.
11. The sol according to claim 1 , wherein the sol is aqueous.
12. The sol according to claim 2 , wherein the axial ratio is in the range of from 10 to 100.
13. The sol according to claim 12 , wherein the axial ratio is in the range of from 11 to 35.
14. The sol according to claim 2 , wherein the silica-based particles have a specific surface area in the range of from 800 to 1600 m 2 /g.
15. The sol according to claim 2 , wherein the silica-based particles have a specific surface area of at least about 1000 m 2 /g.
16. The sol according to claim 2 , wherein the silica-based particles are surface-modified with aluminum.
17. The sol according to claim 2 , wherein the sol has a silica content of at least about 3% by weight.
18. The sol according to claim 2 , wherein the sol has an S-value in the range of from about 5 to about 20%.
19. The sol according to claim 2 , wherein the sol has a pH in the range of from about 7.0 to about 10.0.
20. The sol according to claim 2 , wherein the sol is aqueous.
21. The sol according to claim 1 , wherein the axial ratio is at least 12.
22. The sol according to claim 21 , wherein the axial ratio is at least 13.
23. The sol according to claim 6 , wherein the silica-based particles have a specific surface area in the range of from 1000 to 1600 m 2 /g.
24. The sol according to claim 1 , wherein the sol has an S-value of from about 6 to about 25%.
25. The sol according to claim 1 , wherein the sol has a mole ratio of Si:Al of from about 1:1 to 40:1.
26. The sol according to claim 1 , wherein the sol has a mole ratio of Si:X, where X=alkali metal, of from 5:1 to 30:1.
27. The sol according to claim 26 , wherein the sol has a mole ratio of Si:X, where X=alkali metal, of from 5:1 to 15:1.
28. The sol according to claim 27 , wherein the sol has a mole ratio of Si:X, where X=alkali metal, of at least 8:1.
29. The sol according to claim 27 , wherein the sol has a mole ratio of Si:X, where X=alkali metal, of up to 12:1.
30. The sol according to claim 27 , wherein the silica-based particles have a specific surface area in the range of from 800 to 1600 m 2 /g.
31. Aqueous sol containing silica-based particles having a silica content of at least about 3% by weight, an axial ratio of at least about 10, a mole ratio of Si:X, where X=alkali metal, of from 5:1 to 15:1 and specific surface area of at least about 1000 m 2 /g, wherein the sol is modified with aluminum and has a mole ratio of Si:Al of from about 1:1 to 40:1.
32. The sol according to claim 31 , wherein the sol has an S-value in the range of from about 5 to about 20%.
33. The sol according to claim 31 , wherein the axial ratio is from about 11 to about 35.
34. The sol according to claim 31 , wherein the axial ratio is at least 12.
35. The sol according to claim 31 , wherein the axial ratio is at least 13.
36. The sol according to claim 2 , wherein the sol is modified with aluminum.
37. The sol according to claim 2 , wherein the sol has a mole ratio of Si:Al of from about 1:1 to 40:1.
38. Sol containing silica-based particles having an axial ratio of at least about 10 up to about 100 and specific surface area of at least about 700 m 2 /g.
39. The sol according to claim 38 , wherein the axial ratio is at least about 11.
40. The sol according to claim 38 , wherein the axial ratio is at least 12.
41. The sol according to claim 38 , wherein the axial ratio is at least 13.
42. The sol according to claim 38 , wherein the axial ratio is up to 50.
43. The sol according to claim 38 , wherein the axial ratio is up to about 35.
44. The sol according to claim 38 , wherein the silica-based particles have a specific surface area in the range of from 800 to 1600 m 2 /g.
45. The sol according to claim 38 , wherein the silica-based particles have a specific surface area of at least about 1000 m 2 /g.
46. The sol according to claim 38 , wherein the sol is aqueous.
47. The sol according to claim 38 , wherein the sol has a silica content of at least about 3% by weight.