Process for covering silicas with wax
View Patent ↗The present invention provides a process, which includes: coating at least a portion of a surface of at least one silica particle with at least one wax, wherein the coating is carried out in at least one gas at a temperature above the melting point of the wax and below the decomposition temperature of the wax, to obtain at least one wax-coated silica particle. Other embodiments of the present invention provides processes for impregnating the silica particle with wax and uses of the wax-coated or wax-impregnated particles.
1. A process comprising:
coating at least a portion of a surface of at least one silica particle with at least one wax wherein said coating is carried out in a milling chamber with at least one gas at a temperature above the melting point of said wax, while
spraying a gas heated to a temperature of from 60 to 160° C. into the milling chamber wherein the temperature of the gas at an outlet of the milling chamber is from 40 to 140° C.,
to obtain at least one wax-coated silica particle.
2. The process as claimed in claim 1 , wherein said gas is selected from the group consisting of air, nitrogen, argon, and a mixture thereof.
3. The process as claimed in claim 1 , further comprising
milling said silica particle.
4. The process as claimed in claim 3 , wherein the milling is carried out simultaneously with the coating.
5. The process as claimed in claim 3 , wherein the milling is carried out prior to the coating.
6. The process as claimed in claim 1 , wherein the temperature ranges from 40 to 200° C.
7. The process as claimed in claim 1 , wherein said silica particle is coated with 2 to 15% by weight of wax, relative to the weight of the silica particle.
8. The process as claimed in claim 1 , wherein said wax, silicone-based wax, and mixtures therof.
9. The process as claimed in claim 1 , further comprising classifying said silica particle.
10. The process as claimed in claim 1 , further comprising classifying said wax-coated silica particle.
11. The process as claimed in claim 1 , further comprising producing said silica particle by acidic precipitation.
12. The process as claimed in claim 1 , further comprising prior to said coating, drying said silica particle.
13. The process as claimed in claim 1 , further comprising contacting said wax-coated silica particle with a coating composition.
14. A wax-coated silica particle, produced by the process as claimed in claim 1 .
15. A matting agent, comprising at least one wax-coated silica particle produced by the process as claimed in claim 1 .
16. A coating composition, comprising at least one wax-coated silica particle produced by the process as claimed in claim 1 .
17. An alkyd resin, comprising at least one wax-coated silica particle produced by the process as claimed in claim 1 .
18. A stoving paint, comprising at least one wax-coated silica particle produced by the process as claimed in claim 1 .
19. A process, comprising:
a step for coating at least a portion of a surface of at least one silica particle with at least one wax, wherein said coating is carried out in a milling chamber with at least one gas at a temperature above the melting point of said wax while spraying a gas heated to a temperature of from 60 to 160° C. into the milling chamber, wherein the temperature of the gas at an outlet of the milling chamber is from 40 to 140° C.,
to obtain at least one wax-coated silica particle.
20. A process, comprising:
a step for impregnating at least one pore of at least one silica particle with at least one wax, wherein said coating is carried out in a milling chamber with at least one gas at a temperature above the melting point of said wax while spraying the gas heated to a temperature of from 60 to 160° C. into the milling chamber, wherein the temperature of the gas at an outlet of the milling chamber is from 40 to 140° C.,
to obtain at least one wax-impregnated silica particle.
21. A process, comprising:
impregnating at least one pore of at least one silica particle with at least one wax, wherein said impregnating is carried out in a milling chamber with at least one gas at a temperature above the melting point of said wax while spraying the gas heated to a temperature of from 60 to 160° C. into the milling chamber, wherein the temperature of the gas at an outlet of the milling chamber is from 40 to 140° C.,
to obtain at least one wax-impregnated silica particle.
22. The process as claimed in claim 1 , wherein the wax has a melting point of 64° C. to 112° C.
23. The process as claimed in claim 1 , wherein the wax has a melting point of from 64° C. to 86° C.
24. The wax-coated silica particles as claimed in claim 14 , wherein the wax-coated silica particle does not detach the wax when kept at 50° C. in ethoxypropylacetate.
25. The process as claimed in claim 22 , wherein the coating is carried out at a temperature of from 40° C. to 120° C.
26. The process as claimed in claim 22 , wherein the coating is carried out at a temperature of from 40° C. to 100° C.
27. The process as claimed in claim 22 , wherein the coating is carried out at a temperature of from 40 to 80° C.
28. The process as claimed in claim 1 , wherein the coating is carried out with a single wax.
29. The process as claimed in claim 19 , wherein the coating is carried out with a single wax.
30. The process as claimed in claim 20 , wherein the impregnating is carried out with a single wax.
31. The process as claimed in claim 21 , wherein the impregnating is carried out with a single wax.
32. The process as claimed in claim 1 , wherein the wax has a melting point of from 64° C. to 118° C.