Lipid-treated particles and polymers containing the particles
View Patent ↗A coated particulate solid composition includes a particulate inorganic solid having deposited on its surface a treatment oil comprising lipids. The particulate inorganic solid can include a base particle of titanium dioxide, zinc sulfide, zinc oxide, iron oxide, lead oxide, aluminum oxide, silicon dioxide, zirconium oxide and/or chromium oxide. The treatment oil is optionally a vegetable oil. The treatment oil containing lipids optionally contains glycerides such as triglycerides, and diglycerides, and can contain phospholipids. In one embodiment, the coated particulate solid composition includes particulate titanium dioxide, wherein the treatment oil provides increased bulk density, and enhanced dispersibility in plastic as well as improved lacing resistance.
1. A process for loading particulate titanium dioxide into a polymer concentrate, the process comprising the steps of:
(a) mixing a lipid-containing treatment oil with a particulate titanium dioxide to form a lipid-coated particulate titanium dioxide, wherein the lipid-containing treatment oil comprises at least one of a vegetable oil, a triglyceride, and a diglyceride; and
(b) mixing the lipid-coated particulate titanium dioxide with a polymer resin to form a polymer concentrate, wherein the polymer resin comprises a polyolefin, and wherein the particulate titanium dioxide present in the polymer concentrate is in an amount of from about 50% to about 85% by weight of the polymer concentrate.
2. The process of claim 1 , wherein the treatment oil comprises a vegetable oil.
3. The process of claim 1 , wherein the treatment oil comprises at least one triglyceride.
4. The process of claim 1 , wherein the treatment oil further comprises at least one phospholipid.
5. The process of claim 1 , wherein the polyolefin is selected from the group consisting of polyethylene, polypropylene, and polybutylene, and combinations thereof.
6. The process of claim 1 , wherein the polyolefin is polyethylene.
7. The process of claim 1 , further comprising the step of filtering and washing the particulate titanium dioxide prior to the step of mixing the lipid-containing treatment oil with the particulate titanium dioxide to form the lipid-coated particulate titanium dioxide.
8. The process of claim 7 , further comprising the step of drying the lipid-coated particulate titanium dioxide.
9. The process of claim 1 , further comprising the step of: micronizing the particulate titanium dioxide.
10. The process of claim 9 , wherein the step of mixing the lipid-containing treatment oil with the particulate titanium dioxide to form the lipid-coated particulate titanium dioxide occurs during the step of micronizing the particulate titanium dioxide.
11. The process of claim 9 , wherein the step of mixing the lipid-containing treatment oil with the particulate titanium dioxide occurs prior to the step of micronizing the particulate titanium dioxide.
12. The process of claim 9 , wherein the step of mixing the lipid-containing treatment oil with the particulate titanium dioxide occurs after the step of micronizing the particulate titanium dioxide, and prior to the step of mixing the lipid-coated particulate titanium dioxide with a polymer resin to form a polymer concentrate.
13. The process of claim 1 , wherein the lipid-containing treatment oil is combined with the particulate titanium dioxide pigment in an amount of from about 0.1% to about 5% by weight of the particulate titanium dioxide pigment, based on the weight of the particulate titanium dioxide pigment prior to depositing the lipid-containing treatment oil.
14. The process of claim 1 , wherein the lipid-containing treatment oil is combined with the particulate titanium dioxide in an amount of from about 5% to about 25% by weight of the particulate titanium dioxide pigment, based on the weight of the particulate titanium dioxide pigment prior to depositing the lipid-containing treatment oil.
15. A polymer concentrate comprising particulate titanium dioxide particles coated with a lipid-containing treatment oil and dispersed in a polyolefin polymer matrix, the lipid coated particulate titanium dioxide present in the polymer concentrate in an amount of about 50% to about 87% based on the weight of the polymer matrix, wherein the lipid-containing treatment oil comprises at least one of a vegetable oil, a triglyceride, and a diglyceride.
16. The polymer concentrate of claim 15 , wherein the particulate titanium dioxide particles are coated with a vegetable oil.
17. The polymer concentrate of claim 15 , wherein the particulate titanium dioxide particles are at least partially coated with a triglyceride.
18. The polymer concentrate of claim 15 , wherein the particulate titanium dioxide particles are at least partially coated with a diglyceride.
19. The polymer concentrate of claim 15 , wherein the lipid-containing treatment oil further comprises at least one phospholipid.