U.S. patent application number 10/993456 was filed with the patent office on 2005-10-27 for preparation of organic additive-treated, pyrogenic silica-encapsulated titanium dioxide particles.
Invention is credited to Birmingham, John Nicholas, De La Veaux, Stephan Claude, Hsu, Yunghsing Samson, Jernakoff, Peter, Leary, Kevin Joseph, Musick, Charles David, Niedenzu, Philipp M., Subramanian, Narayanan S..
Application Number | 20050239921 10/993456 |
Document ID | / |
Family ID | 34935691 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050239921 |
Kind Code |
A1 |
Birmingham, John Nicholas ;
et al. |
October 27, 2005 |
Preparation of organic additive-treated, pyrogenic
silica-encapsulated titanium dioxide particles
Abstract
One aspect of the invention is to provide a composition
comprising a titanium dioxide particle having on the surface of
said particle a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; said substantially
encapsulating layer having on its surface at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof. Another aspect of
the invention is to provide processes for producing said
composition.
Inventors: |
Birmingham, John Nicholas;
(Wilmington, DE) ; De La Veaux, Stephan Claude;
(Wilmington, DE) ; Hsu, Yunghsing Samson; (Long
Beach, MS) ; Jernakoff, Peter; (Wilmington, DE)
; Leary, Kevin Joseph; (Middletown, DE) ; Musick,
Charles David; (Waverly, TN) ; Niedenzu, Philipp
M.; (Wilmington, DE) ; Subramanian, Narayanan S.;
(Hockessin, DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY
LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
34935691 |
Appl. No.: |
10/993456 |
Filed: |
November 19, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60565773 |
Apr 27, 2004 |
|
|
|
Current U.S.
Class: |
523/210 ;
524/430 |
Current CPC
Class: |
C01P 2006/60 20130101;
C08K 9/02 20130101; Y10T 428/2998 20150115; C01P 2006/11 20130101;
C01P 2006/64 20130101; C09C 1/3684 20130101; C01P 2006/10 20130101;
Y10T 428/2995 20150115; C01P 2004/62 20130101; C01P 2006/63
20130101; Y10T 428/2991 20150115; C08K 9/04 20130101; C09C 1/3692
20130101; C08K 9/06 20130101; C09C 1/3669 20130101; C09C 1/3676
20130101; C01P 2006/62 20130101 |
Class at
Publication: |
523/210 ;
524/430 |
International
Class: |
C08K 009/10; C08K
003/18 |
Claims
We claim:
1. A composition comprising a titanium dioxide particle having on
the surface of said particle a substantially encapsulating layer
comprising a pyrogenically-deposited metal oxide; said
substantially encapsulating layer having on its surface at least
one organic surface treatment material selected from an
organo-silane, an organo-siloxane, a fluoro-silane, an
organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
2. The composition of claim 1, wherein the at least one organic
surface treatment material is an organo-silane having the formula:
R.sup.5.sub.xSiR.sup.6.sub.4-x wherein R.sup.5 is a nonhydrolyzable
alkyl, cycloalkyl, aryl, or aralkyl group having at least 1 to
about 20 carbon atoms; R.sup.6 is a hydrolyzable alkoxy, halogen,
acetoxy, or hydroxy group; and x=1 to 3.
3. The composition of claim 2, wherein the organo-silane is
octyltriethoxysilane.
4. The composition of claim 1, wherein the at least one organic
surface treatment material is trimethylolpropane.
5. The composition of claim 1, wherein the pyrogenically-deposited
metal oxide is selected from silica, alumina, zirconia, phosphoria,
boria, or mixtures thereof.
6. The composition of claim 5, wherein the pyrogenically-deposited
metal oxide is silica.
7. The composition of claim 1, wherein the at least one organic
surface treatment material is present in a range of from about 0.05
to about 5 wt %.
8. The composition of claim 7, wherein the at least one organic
surface treatment material is present in a range of from about 0.1
to about 1.5 wt %.
9. The composition of claim 1, wherein the at least one organic
surface treatment material is an organic dispersing agent selected
from citric acid, polyacrylic acid, polymethacrylic acid, or
polymeric organic dispersing agent having anionic, cationic,
zwitterionic, or non-ionic functionality derived from a linear,
comb, star, brush, or dendrimer polymer chain and pendant
substituent morphology.
10. The composition of claim 9, wherein the organic dispersing
agent is present in a range of from about 0.01 to about 1.0 wt
%.
11. A pigment comprising a composition of claim 1.
12. A thermoplastic resin comprising the pigment of claim 11.
13. The thermoplastic resin of claim 12, wherein the thermoplastic
resin is a polyolefin resin, an acrylic resin, a polyester resin, a
polyamide resin, an epoxy resin, a phenolic resin, a
poly(vinylaromatic) resin, a poly(vinylhalide) resin, a
polycarbonate resin, a fluoropolymer resin, a elastomeric polymer
resin, a polyurethaneurea resin, a polyurethane resin, a polyacetal
resin, a polyimide resin, a polyetherimide resin, a polyamideimide
resin, a polyetheretherketone resin, a polyetherketoneketone resin,
a liquid crystal polymer resin, or a blend thereof.
14. The thermoplastic resin of claim 13, wherein the polyolefin
resin is polyethylene, polypropylene, or a blend or copolymer
thereof.
15. The thermoplastic resin of claim 14, wherein the polyethylene
is an ultra low density polyethylene, a very low density
polyethylene, a linear low density polyethylene, a low density
polyethylene, a medium density polyethylene, a high density
polyethylene, a high molecular weight high density polyethylene, an
ultra high molecular weight high density polyethylene, an
ethylene/vinyl acetate co-polymer, an ethylene/methacrylic acid
co-polymer, or a blend thereof.
16. The thermoplastic resin of claim 14, wherein the polypropylene
is a homopolymer, a copolymer, a compounded olefin, an in situ
thermoplastic olefin, or a blend thereof.
17. The thermoplastic resin of claim 13, wherein the acrylic resin
is poly(acrylic acid), poly(methacrylic acid),
poly(methylacrylate), poly(methylmethacrylate), or a blend
thereof.
18. The thermoplastic resin of claim 13, wherein the polyester
resin is poly(ethylene terephthalate), poly(butylene
terephthalate), poly(cyclohexylene-dimethylene terephthalate),
poly(trimethylene terephthalate), poly(ethylene naphthalate), or a
blend thereof.
19. The thermoplastic resin of claim 13, wherein the polyamide
resin is nylon 6, nylon 6,6, nylon 6/6,6 co-polymer, nylon 11,
nylon 6,10, nylon 6,12, amorphous nylon, or a blend thereof.
20. The thermoplastic resin of claim 13, wherein the epoxy resin is
poly(epichlorohydrin/bisphenol A); an ester of
poly(epichlorohydrin/bisph- enol A) and a fatty acid, resin acid,
tall oil acid, or a mixture thereof; or a blend thereof.
21. The thermoplastic resin of claim 13, wherein the phenolic resin
is derived from the reaction of formaldehyde with phenol,
resorcinol, cresol, or p-phenylphenol, or a blend thereof.
22. The thermoplastic resin of claim 13, wherein the
poly(vinylaromatic) resin is polystyrene,
poly(styrene-acrylonitrile), poly(acrylonitrile-styrene-butadiene),
poly(acrylonitrile-styrene-acetate- ), or a blend thereof.
23. The thermoplastic resin of claim 13, wherein the
poly(vinylhalide) resin is poly(vinylchloride),
poly(vinylchloride/vinylidene chloride), or a blend thereof.
24. The thermoplastic resin of claim 13, wherein the polycarbonate
resin is bisphenol A polycarbonate or is attained by the
phosgenation of ethylene glycol or propylene glycol, or is a blend
thereof.
25. The thermoplastic resin of claim 13, wherein the fluoropolymer
resin is tetrafluoroethylene/perfluoro(propyl vinyl ether)
co-polymer, polyvinyl fluoride, polyvinylidene fluoride,
tetrafluoroethylene/hexafluo- ropropylene co-polymer,
ethylene/tetrafluoroethylene/perfluorobutyl ethylene ter-polymer,
ethylene/chlorotrifluoroethylene co-polymer, or a blend
thereof.
26. The thermoplastic resin of claim 13, wherein the elastomeric
polymer resin is natural rubber, synthetic rubber, an acrylic,
chlorosulfonated polyethylene, neoprene, a silicone, a urethane, or
a blend thereof.
27. The thermoplastic resin of claim 13, wherein the polyurethane
resin is a polyester- or polyether-based polymer derived from
4,4'-dicyclohexylmethane diisocyanate; hexamethyl diisocyanate;
isophorone diisocyanate; methylene diphenyl diisocyanate; toluene
diisocyanate; tetramethylxylene diisocyanate; o-tolidine
diisocyanate; 1,4-cyclohexane diisocyanate; or a blend thereof.
28. The thermoplastic resin of claim 13, wherein the
polyurethaneurea resin is a polyester-based spandex, a
polyether-based spandex, or a blend thereof.
29. The thermoplastic resin of claim 13, wherein the polyacetal
resin is a polyformaldehyde, a copolymer of formaldehyde and
ethylene oxide, a copolymer of formaldehyde and 1,3-dioxolane, or a
blend thereof.
30. The thermoplastic resin of claim 13, wherein the polyimide
resin is obtained by the reaction of pyromellitic dianhydride and
p-phenylenediamine.
31. The thermoplastic resin of claim 13, wherein the polyetherimide
resin is obtained by the reaction of pyromellitic dianhydride
4,4'-oxydianiline.
32. The thermoplastic resin of claim 13, wherein the polyamideimide
resin is obtained by the reaction of trimellitic anhydride acid
chloride and 1,4-cyclohexanediamine.
33. The thermoplastic resin of claim 13, wherein the
polyetheretherketone is obtained by the reaction of
bis(4-chlorophenyl) ketone and hydroquinone.
34. The thermoplastic resin of claim 13, wherein the
polyetherketoneketone is obtained by the reaction of diphenyl ether
and terephthaloyl chloride.
35. The thermoplastic resin of claim 12, wherein the thermoplastic
resin is pigmented by an extrusion application, a molded article
application, or a post-article forming coating application.
36. The thermoplastic resin of claim 35, wherein extrusion is
performed by cast film extrusion, blown film extrusion, slit film
extrusion, sheet and profile extrusion, fiber and filament
extrusion, or wire coating extrusion.
37. The thermoplastic resin of claim 35, wherein the molded article
application is performed by injection molding, blow molding, or
rotational molding.
38. The thermoplastic resin of claim 35, wherein the post-article
forming coating application is performed by powder coating, roll-on
coating, brush-on coating, trowel-on coating, or spray-on
coating.
39. A method for producing high lacing resistant,
semi-photodurable, stabilizer-derived yellowing resistant titanium
dioxide particles comprising: (a) providing titanium dioxide
particles having on the surface of said particles a substantially
encapsulating layer comprising a pyrogenically-deposited metal
oxide; (b) treating said particles with at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; and (c) optionally,
repeating step (b).
40. The method of claim 39, wherein the at least one organic
surface treatment material is an organo-silane having the formula:
R.sup.5.sub.xSiR.sup.6.sub.4-x wherein R.sup.5 is a nonhydrolyzable
alkyl, cycloalkyl, aryl, or aralkyl group having at least 1 to
about 20 carbon atoms; R.sup.6 is a hydrolyzable alkoxy, halogen,
acetoxy, or hydroxy group; and x=1 to 3.
41. The method of claim 40, wherein the organo-silane is
octyltriethoxysilane.
42. The method of claim 39, wherein the at least one organic
surface treatment material is trimethylolpropane.
43. The method of claim 39, wherein the pyrogenically-deposited
metal oxide is selected from silica, alumina, zirconia, phosphoria,
boria, or a mixture thereof.
44. The method of claim 43, wherein the pyrogenically-deposited
metal oxide is silica.
45. A method for producing high lacing resistant,
semi-photodurable, stabilizer-derived yellowing resistant titanium
dioxide particles comprising: (a) providing a slurry comprising
titanium dioxide particles having on the surface of said particles
a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; (b) adjusting the pH of the
slurry to aid in neutralization of residual chlorine; (c) adjusting
the pH of the slurry to aid in filtration of the slurry; (d)
treating the slurry with at least one organic surface treatment
material selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (e) filtering the
slurry to produce a filter cake; (f) optionally, during or after
step (e), treating the filter cake with at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (g) drying the
filter cake; (h) optionally, during or after step (g), treating the
filter cake with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (i) deagglomerating
titanium dioxide particles from the treated filter cake; and (j)
optionally, during or after step (i), treating the titanium dioxide
particles with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
46. A method for producing high lacing resistant,
semi-photodurable, stabilizer-derived yellowing resistant titanium
dioxide particles comprising: (a) providing a slurry comprising
titanium dioxide particles having on the surface of said particles
a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; (b) adjusting the pH of the
slurry to aid in neutralization of residual chlorine; (c) adjusting
the pH of the slurry to aid in filtration of the slurry; (d)
filtering the slurry to produce a filter cake; (e) during or after
step (d), treating the filter cake with at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (f) drying the
filter cake; (g) optionally, during or after step (f), treating the
filter cake with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (h) deagglomerating
titanium dioxide particles from the treated filter cake; and (i)
optionally, during or after step (h), treating the titanium dioxide
particles with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
47. A method for producing high lacing resistant,
semi-photodurable, stabilizer-derived yellowing resistant titanium
dioxide particles comprising: (a) providing a slurry comprising
titanium dioxide particles having on the surface of said particles
a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; (b) adjusting the pH of the
slurry to aid in neutralization of residual chlorine; (c) adjusting
the pH of the slurry to aid in filtration of the slurry; (d)
filtering the slurry to produce a filter cake; (e) drying the
filter cake; (f) during or after step (e), treating the filter cake
with at least one organic surface treatment material selected from
an organo-silane, an organo-siloxane, a fluoro-silane, an
organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; (g) deagglomerating
titanium dioxide particles from the treated filter cake; and (h)
optionally, during or after step (g), treating the titanium dioxide
particles with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
48. A method for producing high lacing resistant,
semi-photodurable, stabilizer-derived yellowing resistant titanium
dioxide particles comprising: (a) providing a slurry comprising
titanium dioxide particles having on the surface of said particles
a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; (b) adjusting the pH of the
slurry to aid in neutralization of residual chlorine; (c) adjusting
the pH of the slurry to aid in filtration of the slurry; (d)
filtering the slurry to produce a filter cake; (e) drying the
filter cake; (f) adding the filter cake into a micronizer; (g)
adding to the micronizer feed block or to conveyed particles up to
about several feet past the exit of the micronizer at least one
organic surface treatment material selected from an organo-silane,
an organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; and (h) optionally,
treating the micronized particles with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/565,773, filed Apr. 27, 2004 incorporated by
reference herein in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a process for producing titanium
dioxide particles suitable for incorporation at high loadings into
polymer matrices, said particles possessing the attributes of a
high degree of polymer additive derived discolouration resistance,
good photodurability, excellent volatilization resistance, high
dispersibility, good processing in high load polymer matrices,
excellent optical properties, and high bulk density.
BACKGROUND OF THE INVENTION
[0003] The surface application of certain organosilicon compounds
to initially untreated, chloride process-derived titanium dioxide
particles has been described for allowing incorporation of the
particles at high loadings, high processing rates and with a high
degree of dispersion into various thermoplastic polymer matrices,
particularly polyolefin derived matrices, see for example, U.S.
Pat. Nos. 5,607,994; 5,631,310; 5,889,090; and 5,959,004. In
addition, the treatment has been known to allow the subsequent
production of finished articles, e.g., films, which are unaffected
by the development of imperfections because of the release of
particle associated volatiles. During high temperature thin film
fabrication, these imperfections are typically referred to as
lacing.
[0004] However, a problem associated with use of these surface
treated particles is their inability to varying degrees to resist
the UV light induced formation of chromophores (typically yellow)
when the particles are incorporated into polymer matrices
possessing (in concert) certain types of phenolic stabilizers (such
as, for example, butylated hydroxytoluene or butylated
hydroxyanisole) and hindered amine light stabilizers (such as, for
example, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate). Another
problem is their inability to yield particle/polymer composites
that possess any significant photodurability, that is, resistance
of the particle/polymer composite to UV light induced
degradation.
[0005] Substantially encapsulating the particles, before the
addition of any organic surface treatment, with certain metal
oxides (for example, silica, alumina, or mixtures thereof deposited
in an aqueous environment by either batch or continuous operations
has been described to solve the problems of chromophore formation
and photodurability, see, for example, U.S. Pat. Nos. 3,437,502;
5,993,533; and 6,783,586. However, a serious disadvantage of this
solution is that the resulting metal oxide shell is prone to
moisture retention and/or moisture generation which can, under high
temperature fabrication conditions, result in the formation of the
aforementioned polymer matrix imperfections, e.g., lacing in high
temperature thin film fabrication.
[0006] It has now been found that the above-described problems and
disadvantages can be significantly overcome and the highly
desirable benefits associated with the aforementioned organosilane
surface treatment technology retained by coupling an organosilane
surface treatment with the encapsulation technology described in
U.S. patent Publication No. 2003/0051635, incorporated herein by
reference in its entirety. The encapsulation technology described
in U.S. patent Publication No. 2003/0051635 encapsulates titanium
dioxide particles with a thin shell of pyrogenically deposited
silica. It has surprisingly been found that combining these
techniques allows the preparation, using standard commercial
production equipment, of titanium dioxide particles possessing the
attributes of a high degree of polymer additive derived
discolouration resistance, good photodurability, excellent
volatilization resistance, high dispersibility, good processing in
high load polymer matrices, excellent optical properties, and high
bulk density.
SUMMARY OF THE INVENTION
[0007] One aspect of this invention is to provide a composition
comprising a titanium dioxide particle having on the surface of
said particle a substantially encapsulating layer comprising a
pyrogenically-deposited metal oxide; said substantially
encapsulating layer having on its surface at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
[0008] In a preferred embodiment, the at least one organic surface
treatment material is an organo-silane having the formula:
R.sup.5.sub.xSiR.sup.6.sub.4-x
[0009] wherein
[0010] R.sup.5is a nonhydrolyzable alkyl, cycloalkyl, aryl, or
aralkyl group having at least 1 to about 20 carbon atoms;
[0011] R.sup.6 is a hydrolyzable alkoxy, halogen, acetoxy, or
hydroxy group; and
[0012] x=1 to 3.
[0013] Octyltriethoxysilane is a preferred organo-silane.
[0014] Also provided are pigments and thermoplastic resins
comprising a composition of the invention.
[0015] Another aspect of the invention is to provide a method for
producing high lacing resistant, semi-photodurable,
stabilizer-derived yellowing resistant titanium dioxide particles
comprising:
[0016] (a) providing titanium dioxide particles having on the
surface of said particles a substantially encapsulating layer
comprising a pyrogenically-deposited metal oxide;
[0017] (b) treating said particles with at least one organic
surface treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; and
[0018] (c) optionally, repeating step (b).
[0019] A further aspect is to provide a method for producing high
lacing resistant, semi-photodurable, stabilizer-derived yellowing
resistant titanium dioxide particles comprising:
[0020] (a) providing a slurry comprising titanium dioxide particles
having on the surface of said particles a substantially
encapsulating layer comprising a pyrogenically-deposited metal
oxide;
[0021] (b) adjusting the pH of the slurry to aid in neutralization
of residual chlorine;
[0022] (c) adjusting the pH of the slurry to aid in filtration of
the slurry;
[0023] (d) treating the slurry with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0024] (e) filtering the slurry to produce a filter cake;
[0025] (f) optionally, during or after step (e), treating the
filter cake with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0026] (g) drying the filter cake;
[0027] (h) optionally, during or after step (g), treating the
filter cake with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0028] (i) deagglomerating titanium dioxide particles from the
treated filter cake; and
[0029] (j) optionally, during or after step (i), treating the
titanium dioxide particles with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
[0030] Also provided is a method for producing high lacing
resistant, semi-photodurable, stabilizer-derived yellowing
resistant titanium dioxide particles comprising:
[0031] (a) providing a slurry comprising titanium dioxide particles
having on the surface of said particles a substantially
encapsulating layer comprising a pyrogenically-deposited metal
oxide;
[0032] (b) adjusting the pH of the slurry to aid in neutralization
of residual chlorine;
[0033] (c) adjusting the pH of the slurry to aid in filtration of
the slurry;
[0034] (d) filtering the slurry to produce a filter cake;
[0035] (e) during or after step (d), treating the filter cake with
at least one organic surface treatment material selected from an
organo-silane, an organo-siloxane, a fluoro-silane, an
organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0036] (f) drying the filter cake;
[0037] (g) optionally, during or after step (f), treating the
filter cake with at least one organic surface treatment material
selected from an organo-silane, an organo-siloxane, a
fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0038] (h) deagglomerating titanium dioxide particles from the
treated filter cake; and
[0039] (i) optionally, during or after step (h), treating the
titanium dioxide particles with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
[0040] A further aspect is to provide a method for producing high
lacing resistant, semi-photodurable, stabilizer-derived yellowing
resistant titanium dioxide particles comprising:
[0041] (a) providing a slurry comprising titanium dioxide particles
having on the surface of said particles a substantially
encapsulating layer comprising a pyrogenically-deposited metal
oxide;
[0042] (b) adjusting the pH of the slurry to aid in neutralization
of residual chlorine;
[0043] (c) adjusting the pH of the slurry to aid in filtration of
the slurry;
[0044] (d) filtering the slurry to produce a filter cake;
[0045] (e) drying the filter cake; during or after step (e),
treating the filter cake with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof;
[0046] (g) deagglomerating titanium dioxide particles from the
treated filter cake; and
[0047] (h) optionally, during or after step (g), treating the
titanium dioxide particles with at least one organic surface
treatment material selected from an organo-silane, an
organo-siloxane, a fluoro-silane, an organo-phosphonate, an
organo-acid phosphate, an organo-pyrophosphate, an
organo-polyphosphate, an organo-metaphosphate, an
organo-phosphinate, an organo-sulfonic compound, a
hydrocarbon-based carboxylic acid, an associated ester of a
hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
[0048] Another aspect is to provide a method for producing high
lacing resistant, semi-photodurable, stabilizer-derived yellowing
resistant titanium dioxide particles comprising:
[0049] (a) providing a slurry comprising titanium dioxide particles
having on the surface of said particles a substantially
encapsulating layer comprising a pyrogenically-deposited metal
oxide;
[0050] (b) adjusting the pH of the slurry to aid in neutralization
of residual chlorine;
[0051] (c) adjusting the pH of the slurry to aid in filtration of
the slurry;
[0052] (d) filtering the slurry to produce a filter cake;
[0053] (e) drying the filter cake;
[0054] (f) adding the filter cake into a micronizer;
[0055] (g) adding to the micronizer feed block or to conveyed
particles up to about several feet past the exit of the micronizer
at least one organic surface treatment material selected from an
organo-silane, an organo-siloxane, a fluoro-silane, an
organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof; and
[0056] (h) optionally, treating the micronized particles with at
least one organic surface treatment material selected from an
organo-silane, an organo-siloxane, a fluoro-silane, an
organo-phosphonate, an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, an organo-phosphinate, an organo-sulfonic
compound, a hydrocarbon-based carboxylic acid, an associated ester
of a hydrocarbon-based carboxylic acid, a derivative of a
hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low
molecular weight hydrocarbon wax, a low molecular weight
polyolefin, a co-polymer of a low molecular weight polyolefin, a
hydrocarbon-based polyol, a derivative of a hydrocarbon-based
polyol, an alkanolamine, a derivative of an alkanolamine, an
organic dispersing agent, or a mixture thereof.
[0057] Other objects and advantages of the present invention will
become apparent to those skilled in the art upon reference to the
detailed description that hereinafter follows.
DETAILED DESCRIPTION OF THE INVENTION
[0058] Applicants specifically incorporate the entire content of
all cited references in this disclosure. Further, when an amount,
concentration, or other value or parameter is given as either a
range, preferred range, or a list of upper preferable values and
lower preferable values, this is to be understood as specifically
disclosing all ranges formed from any pair of any upper range limit
or preferred value and any lower range limit or preferred value,
regardless of whether ranges are separately disclosed. Where a
range of numerical values is recited herein, unless otherwise
stated, the range is intended to include the endpoints thereof, and
all integers and fractions within the range. It is not intended
that the scope of the invention be limited to the specific values
recited when defining a range.
[0059] "Substantially encapsulating layer", as used herein, means
that the surface of the titanium dioxide particle is predominately
covered with a layer of pyrogenic metal oxide.
[0060] Titanium dioxide particles suitable for use in the invention
are those that have been substantially encapsulated with a
pyrogenic metal oxide. Methods such as, for example, those
disclosed in co-owned, co-pending U.S. patent Publication No.
2003/0051635, incorporated herein by reference, are particularly
suitable for producing titanium dioxide particles substantially
encapsulated with a pyrogenic metal oxide.
[0061] The composition of the oxide treatment deposited on the
titanium dioxide particles is an amorphous pyrogenically-deposited
metal oxide. Preferably, the pyrogenically-deposited metal oxide is
silica, alumina, zirconia, phosphoria, boria, or mixtures thereof.
Most preferred is silica, such as pyrogenic silica deposited by a
process disclosed in U.S. patent Publication No. 2003/0051635. The
thickness of the treatment layer deposited is typically in a range
of from about 2 to about 6 nm, but any amount of deposited
pyrogenic metal oxide is suitable. The particles are typically more
than 99% rutile.
[0062] The method of adding the at least one organic surface
treatment material to the titanium dioxide particles substantially
encapsulated with pyrogenically-deposited metal oxide of the
present invention is not especially critical, and said TiO2
particles may be treated with the at least one organic surface
treatment material in a number of ways. For example, the at least
one organic surface treatment material can be added either neat or
via solution to said TiO2 particles while said particles are either
in a dry state or in a wet state. Examples involving the former
state include, but are not limited to, the addition of said
material (1) to conveyed particles via injector mixer technology
such as that described in U.S. Pat. No. 4,430,001 or as described
in WO 97/07879 published Mar. 6, 1997, and assigned to E.I. du Pont
de Nemours and Company or (2) to particles undergoing
deagglomeration in a micronizer (said material typically added to
the micronizer feed block or to conveyed pigment up to about
several feet past the exit of the micronizer) or in a dry media
mill. Examples involving the latter state include, but are not
limited to, the addition of said material (1) to particles present
in slurry form either separate from or during filtration, (2) to
particle wet cake after filtration but before drying, (3) to
particles that are being dried by, for example, flash dryer or
spray drier based techniques or (4) to particles undergoing
deagglomeration via wet media milling techniques. In addition, the
at least one organic surface treatment material can be added in
portions at different processing stages. For example, one-half of
said material can be added during a drying step and the remaining
half at a subsequent stage such as during a deagglomeration
operation such as during micronizing.
[0063] Suitable organic surface treatment materials include, but
are not limited to, for example, organo-silanes; organo-siloxanes;
fluoro-silanes; organo-phosphonates; organo-phosphoric acid
compounds such as organo-acid phosphates, organo-pyrophosphates,
organo-polyphosphates, and organo-metaphosphates;
organo-phosphinates; organo-sulfonic compounds; hydrocarbon-based
carboxylic acids and associated derivatives and polymers;
hydrocarbon-based amides; low molecular weight hydrocarbon waxes;
low molecular weight polyolefins and co-polymers thereof;
hydrocarbon-based polyols and derivatives thereof; alkanolamines
and derivatives thereof; and commonly utilized organic dispersing
agents; all the above utilized either individually or as mixtures,
applied in concert or sequentially. Preferably, the surface of the
titanium dioxide particles substantially encapsulated with a
pyrogenically-deposited metal oxide are treated with an
organo-silane.
[0064] Suitable organo-silanes for use in the practice of this
invention include silanes disclosed in U.S. Pat. No. 5,560,845
issued to Birmingham, Jr. et al. on Oct. 1, 1996, having the
general formula
SiR.sup.1R.sup.2R.sup.3R.sup.4 (I)
[0065] in which at least one R is a non-hydrolyzable organic group,
such as alkyl, cycloalkyl, aryl, or aralkyl, having 1-20 carbon
atoms, preferably 4-20 carbon atoms, most preferably 6-20 carbon
atoms, and at least one R is a hydrolyzable group such as alkoxy,
halogen, acetoxy, or hydroxy. The other two R are, independently,
hydrolyzable or non-hydrolyzable as above. It is preferred that at
least two, and especially that three, of the R are hydrolyzable.
The non-hydrolyzable R can be fully or partially fluorine
substituted. A silane having the foregoing description is herein
called "organo-silane" in reference to the non-hydrolyzable R
group(s). Organo-silanes may be linear or branched, substituted or
unsubstituted, and saturated or unsaturated. Preferably,
non-hydrolyzable R are non-reactive. Alkyl, cycloalkyl, aryl, and
aralkyl are preferred non-hydrolyzable R, with alkyl being most
preferred, including the possibility of any of these groups being
fully or partially fluorine substituted. When the hydrolyzable R
are identical, the organo-silane can be represented by
R.sup.5.sub.xSiR.sup.6.sub.4-x (II)
[0066] in which R.sup.5 is non-hydrolyzable and R.sup.6 is
hydrolyzable as defined above and x=1-3. Preferred R.sup.6 include
methoxy, ethoxy, chloro, and hydroxy. Ethoxy is especially
preferred for ease of handling. Preferred organo-silanes include
octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane,
dodecyltriethoxysilane, tridecyltriethoxysilane,
tetradecyltriethoxysilane, pentadecyltriethoxysilane,
hexadecyltriethoxysilane, heptadecyltriethoxysilane and
octadecyltriethoxysilane. Mixtures of organo-silanes can be
used.
[0067] In embodiments utilizing organo-silanes represented by
Formula II, preferred silanes are R.sup.5=8-18 carbon atoms;
R.sup.6=ethoxy; and x=1 to 3. The R.sup.5=8-18 carbon atoms are
preferred, for example for enhanced processibility. R.sup.6=ethoxy
is preferred for ease of handling. Most preferred is
octyltriethoxysilane.
[0068] Suitable organo-siloxanes for use in the practice of this
invention are of the general formula
[R.sup.7.sub.nSiO.sub.(4-n)/2].sub.m (III)
[0069] in which R.sup.7 may be organic or inorganic, n=0-3, and
m.gtoreq.2. Polydimethylsiloxane (PDMS), terminated in a multitude
of different ways, for example, by trimethylsilyl functionality,
and the like are the preferred polysiloxanes. Additionally useful
organo-siloxanes include, for example, polymethylhydrosiloxane
(PMHS) and polysiloxanes derived from the functionalization (by
hydrosilylation) of PMHS with olefins.
[0070] Organo-silanes and polysiloxanes are commercially available
or can be prepared by processes known in the art. See, for example,
S. Pawlenko, "Organosilicon Compounds", G. Thieme Verlag, N.Y.
(1980).
[0071] Suitable organo-phosphonates for use in the practice of this
invention are disclosed in U.S. Pat. No. 5,837,049 issued to Watson
et al. on Nov. 17, 1998, and have the general formula 1
[0072] in which R.sup.8 is an alkyl group or a cycloalkyl group
containing 1 to 22 carbon atoms and R.sup.9 and R.sup.10 are each,
independently, hydrogen, an alkyl group, a cycloalkyl group, an
aryl group, or an aralkyl group. Preferably, R.sup.8 contains from
1 to 20, more preferably 4-20, and even more preferably 6-20 carbon
atoms and is a straight chain alkyl group. However,
organo-phosphonates possessing linear or branched, substituted or
unsubstituted and saturated and unsaturated R.sup.8, R.sup.9 and
R.sup.10 functionality are suitable for use. Organo-phosphonates of
use include n-octylphosphonic acid and its esters,
n-decylphosphonic acid and its esters, 2-ethylhexylphosphonic acid
and its esters, and camphyl phosphonic acid and its esters.
[0073] When R.sup.9 and R.sup.10 are both hydrogen, the above
Formula IV represents an organo-phosphonic acid, and when at least
one of R.sup.9 and R.sup.10 is a hydrocarbyl group, the formula
represents an ester of an organo-phosphonic acid. In the case of
esters, R.sup.9 and R.sup.10 preferably contain up to 10 carbon
atoms and more preferably up to 8 carbon atoms (i.e., the ester is
an ester of an alcohol containing up to 10, and preferably up to 8
carbon atoms). R.sup.9 and R.sup.10 can be different but frequently
are the same. Suitable esters include ethyl esters, butyl esters,
octyl esters, cyclohexyl esters, and phenyl esters.
[0074] In addition to the above described organo-phosphonates, one
can also envision utilizing in the practice of this invention
organo-phosphonate derivatives possessing hydrolyzable halogen
functionality examples of which include, but are not limited to,
n-octylphosphonic dichloride, n-decylphosphonic dichloride and
2-ethylhexylphosphonic dichloride.
[0075] Suitable organo-phosphoric acid compounds for use in the
practice of this invention include an organo-acid phosphate, an
organo-pyrophosphate, an organo-polyphosphate, an
organo-metaphosphate, or a salt of any of the aforementioned
organo-phosphoric acid compounds as disclosed in U.S. Pat. No.
6,713,543 issued to El-Shoubary et al. on Mar. 30, 2004. Suitable
organo-acid phosphates have the general formula
(R.sup.11--O).sub.yPO(OH).sub.z (V)
[0076] wherein y=1 or 2; z=3-y; and R.sup.11 is an organic group
having from 2 to 22 carbon atoms.
[0077] The phrase "organo-acid phosphate" as used herein refers to
a compound that may be represented by Formula V. In the organo-acid
phosphate of Formula V, the organic groups may be linear or
branched, substituted or unsubstituted, and saturated or
unsaturated. Preferably R.sup.11 is a linear hexyl- or
octyl-aliphatic group or a branched hexyl- or octyl-aliphatic
group.
[0078] Suitable organo-pyrophosphate or organo-polyphosphate
compounds may be represented by the formula:
R.sup.12.sub.a--P.sub.(a-2)O.sub.4+[3(a-3)] (VI)
[0079] wherein a=4-14; and each R.sup.12 is an organic group having
from 2 to 22 carbon atoms or hydrogen and within any one molecule,
any two or more R.sup.12 groups may be the same provided that at
least one of the R.sup.12 groups is not hydrogen.
[0080] The symbol R.sup.12 as used in Formula VI denotes any
organic group that contains from 2 to 22 carbon atoms or hydrogen.
Within any molecule the R.sup.12 groups may all be the same moiety
or they may be different moieties. These organic groups may be
linear or branched, substituted or unsubstituted, and saturated or
unsaturated. If the R.sup.12 groups are all the same moieties, then
they cannot be hydrogen. Preferably at least one of the R.sup.12
groups is hydrogen and at least one of the R.sup.12 groups will be
linear hexyl or octyl aliphatic groups or branched hexyl or octyl
aliphatic groups. Examples of organopyrophosphate acid compounds
and organopolyphosphate acid compounds include caprylpyrophosphate,
2-ethylhexylpyrophosphate, dihexylpyrophosphate,
dihexylammoniumpyrophosp- hate, dioctylpyrophosphate,
diisooctylpyrophosphate, dioctyltriethanolaminepyrophosphate,
bis(2-ethylhexyl)pyrophosphate, bis(2-ethylhexyl)sodium
pyrophosphate, tetraethylpyrophosphate, tetrabuytipyrophosphate,
tetrahexylpyrophosphate, tetraoctylpyrophosphate- ,
pentahexyltripolyphosphate, pentaoctyltripolyphosphate, tetrahexyl
sodium tripolyphosphate, tetrahexylammoniumtripolyphosphate,
pentahexyl sodium tetrapolyphosphate, trioctyl sodium
tetrapolyphosphate, trioctyl potassium tetrapolyphosphate,
hexabutyltetrapolyphosphate, hexahexyltetrapolyphosphate, and
hexaoctyltetrapolyphosphate.
[0081] Suitable organo-metaphosphate compounds may be represented
by the formula:
(R.sup.13PO.sub.3).sub.b (VII)
[0082] wherein b=1-14, and each R.sup.13 is an organic group having
from 2 to 22 carbon atoms or hydrogen and within any one molecule,
any two or more R.sup.13 groups may be the same provided that at
least one of the R.sup.13 groups is not hydrogen.
[0083] The symbol R.sup.13 as used in Formula VII denotes any
organic group that contains from 2 to 22 carbon atoms or hydrogen.
These organic groups may be linear or branched, substituted or
unsubstituted, and saturated or unsaturated. "b" may be from about
1 to about 14, and preferably "b" is from about 4 to about 14.
Within any molecule, the R.sup.13 groups may all be the same moiety
or they may be different moieties. If the R.sup.13 groups are all
the same moieties, then they cannot be hydrogen. Preferably at
least one of the R.sup.13 groups will be a linear hexyl or octyl
aliphatic group or a branched hexyl or octyl aliphatic group.
Examples of organo-metaphosphates include ethylmetaphosphate,
propylmetaphosphate, butylmetaphosphate, hexylmetaphosphate, and
octylmetaphosphate.
[0084] The organo-phosphoric acids of the present invention may be
utilized in their acidic or salt forms. Examples of salts useful
with the present invention are the potassium, sodium, ammonium, and
aluminum salts and salts formed with alkanolamines such as
triethanolamine of the substances identified by Formula V, Formula
VI, or Formula VII.
[0085] Organo-acid phosphates are readily available commercially or
may be prepared by procedures known or knowable to those skilled in
the art such as those procedures disclosed in U.S. Pat. No.
4,350,645, issued to Kurosaki et al. on Sep. 21, 1982.
Organo-pyrophosphates and organo-polyphosphates are readily
available commercially or produced according to the procedures that
are known or easily knowable to persons skilled in the art.
Organo-metaphosphates may also be produced according to the
procedures that are known or easily knowable to persons skilled in
the art. Examples of these procedures for synthesizing
organo-pyrophosphates, organo-polyphosphates, and
organo-metaphosphates are described in Alder, Howard and Woodstock,
Willard Chem, Indus., 1942, 51:516.
[0086] Suitable organo-phosphinates for use in the practice of this
invention include those which are represented by the general
formulas
R.sup.14P(O)H(OR.sup.15) (VII)
and
R.sup.16R.sup.17 P(O)(OR.sup.18) (IX)
[0087] in which R.sup.14, R.sup.16, R.sup.17 are alkyl groups or
cycloalkyl groups containing 1 to 22 carbon atoms and R.sup.15 and
R.sup.18 are each, independently, hydrogen, an alkyl group, a
cycloalkyl group, an aryl group, or an aralkyl group. Preferably,
R.sup.14, R.sup.16, R.sup.17 contain from 1 to 20, more preferably
4-20, and even more preferably 6-20 carbon atoms and are straight
chain alkyl groups. However, organo-phosphinates possessing linear
or branched, substituted or unsubstituted and saturated and
unsaturated R.sup.14, R.sup.15, R.sup.16, R.sup.17, and R.sup.18
functionality are suitable for use. R.sup.16 and R.sup.17 can be
different but frequently are the same. Phosphorus compounds of use
include, but are not limited to, n-hexylphosphinic acid and its
esters (VIII), n-octylphosphinic acid and its esters (VIII),
di-n-hexylphosphinic acid and its esters (IX) and
di-n-octylphosphinic acid and its esters (IX).
[0088] When R.sup.15 and R.sup.18 are both hydrogen the above
formula represents an organo-phosphinic acid and when at least one
of R.sup.15 and R.sup.18 is a hydrocarbyl group the formula
represents an ester of an organo-phosphinic acid. In the case of
esters, preferably, R.sup.15 and R.sup.18 contain up to 10 carbon
atoms and more preferably up to 8 carbon atoms (i.e. the ester is
an ester of an alcohol containing up to 10, and preferably up to 8
carbon atoms). Suitable esters include ethyl esters, butyl esters,
octyl esters, cyclohexyl esters, and phenyl esters.
[0089] In addition to the above described organo-phosphinates, one
can also envision utilizing in the practice of this invention
organo-phosphinate derivatives possessing hydrolyzable halogen
functionality examples of which include, but are not limited to,
chloroethylphosphine oxide and chlorodiethylphosphine oxide.
[0090] Organo-sulfonic compounds, as disclosed in U.S. Pat. No.
6,646,037 issued to El-Shoubary et al. on Nov. 11, 2003, may in
general be represented by Formula X, which includes not only
organo-sulfonic acids, but also their salts. These organo-sulfonic
compounds of Formula X may be synthesized de novo or obtained from
commercial sources. Formula X is:
(R.sup.19SO.sub.3).sub.cM.sup.c+ (X)
[0091] where R.sup.19 represents a saturated, unsaturated,
branched, linear, or cyclic organic group having from 2 to 22
carbon atoms; c equals 1, 2, 3, or 4; and M represents hydrogen, a
metal ion, ammonium ion or organoammonium ion such as protonated
triethanolamine. Preferably, if M is a metal ion, it is a metal ion
with a valence of +1, +2, +3, or +4 such as Na.sup.1+, Ca.sup.2+,
Mg.sup.2+, Al.sup.3+, or Ti.sup.4+. Preferably, R.sup.19 is hexyl-,
octyl-, or 2-ethylhexyl-.
[0092] Suitable hydrocarbon-based carboxylic acids for use in the
practice of this invention include those that possess linear or
branched, substituted or unsubstituted and saturated or unsaturated
(including aromatic) functionality as well as one or more
carboxylic acid groups. Preferably, said acids will possess about
2-28, more preferably 2-18, and most preferably 2-12 carbon atoms.
Said acids can be applied to the particle surface both as the free
acid or as a neutralized salt. Examples of suitable acids include
maleic, malonic, fumaric, benzoic, phthalic, stearic, oleic, and
linoleic.
[0093] Also suitable for use in the practice of this invention are
esters and partial esters formed by the reaction of the above
described hydrocarbon-based carboxylic acids with organic hydroxy
compounds that possess linear or branched, substituted or
unsubstituted, and saturated or unsaturated (including aromatic)
functionality and, typically, 1 to 6 hydroxyl (OH) groups. Examples
of appropriate non-aromatic hydroxy compounds include, but are not
limited to, ethylene glycol, propylene glycol, trimethylolpropane,
diethanolamine, triethanolamine, glycerol, hexanetriol, erythritol,
mannitol, sorbitol, and pentaerythritol. Examples of appropriate
aromatic hydroxy compounds include, but are not limited to,
bisphenol A, hydroquinone, and phloroglucinol. Said esters and
partial esters are described in U.S. Pat. No. 5,288,320 issued to
Decelles on Feb. 22, 1994.
[0094] Polyesters derived from the self-condensation of, for
example, 12-hydroxystearic acid or from, for example, the
condensation of a dicarboxylic acid containing compound with a
dihydroxyl containing compound can also be utilized for the current
invention.
[0095] Suitable hydrocarbon-based amides for use in the practice of
this invention include those that possess linear or branched,
substituted or unsubstituted and saturated or unsaturated
(including aromatic) functionality. Preferably, said amides will
possess about 8-22, more preferably 12-22, and most preferably
18-22 carbon atoms. Examples of suitable amides include stearamide,
oleamide, and erucamide.
[0096] Also suitable for use in the practice of this invention are
surface treatments derived from relatively low molecular weight
hydrocarbon waxes and polyolefins, the latter either homopolymeric,
for example, polyethylene or polypropylene, or derived from the
co-polymerization of, for example, ethylene with one or more of
propylene, butylene, vinylacetate, acrylates, or acrylamide.
[0097] In addition to the above described additives, one can also
utilize as particle surface treatments in the practice of this
invention hydrocarbon-based polyols, alkanolamines, and derivatives
thereof, for example, esters and partial esters. Examples of said
polyols include species such as glycerol and the commonly utilized
particle grinding aids trimethylolethane and trimethylolpropane.
Examples of said alkanolamines include diethanolamine and
triethanolamine.
[0098] Common organic dispersing agents that are of use in the
practice of this invention include, but are not limited to, citric
acid, polyacrylic acid, and polymethacrylic acid as well as the
more complex, specialty polymeric organic dispersing agents
possessing anionic, cationic, zwitterionic, or non-ionic
functionality and whose structures are typically trade secrets but
are usually derived from linear, comb, star, brush, or dendrimer
based polymer chain and pendant substituent morphologies.
[0099] Note that, in conjunction with the above, organic surface
treatments may also be used various inorganic based dispersing aids
which are usually phosphate, polyphosphate, pyrophosphate, and
metaphosphate derived and are typically added, either as the acids
or associated salts, to particle slurries.
[0100] Mixtures of organic surface treatment materials are
contemplated, including mixtures of organic surface treatment
materials from within one class of compounds, for example mixtures
of organo-silanes, or mixtures of organic surface treatment
materials from within two or more classes, for examples mixtures
organo-silanes and organo-phosphonates.
[0101] Weight content of the organic surface treatment material,
based on total TiO.sub.2, is typically about 0.05 to about 5 weight
%, preferably about 0.1 to about 1.5 weight %. In excess of 5
weight % may be used.
[0102] While titanium dioxide particles substantially encapsulated
with a pyrogenically-deposited metal oxide can be treated with only
one organic surface treatment material or mixtures of said material
added in a single treatment step, alternative embodiments
contemplate subsequent treatment of said titanium dioxide particles
with additional organic surface treatment materials. Thus, for
example, titanium dioxide particles previously treated with one
organic surface treatment material can be treated with the same
organic surface treatment material repeating the previous treatment
method or using another treatment method. Alternatively, a
different organic surface treatment material can be added through
an identical treatment method or through another treatment method.
Treatments beyond one additional treatment are contemplated.
[0103] Weight content of the organic surface treatment material in
layers beyond the first layer of organic surface treatment
material, based on total TiO.sub.2, is typically about 0.01 to
about 1.0 weight %, but higher amounts are acceptable.
[0104] As described above for the initial treatments of organic
surface treatment material, the method of adding additional
treatments of organic surface treatment materials is not especially
critical, and any of the aforementioned methods may be used for
subsequent treatments. In a preferred embodiment, the additional
layers of organic surface treatment material beyond the first layer
of organic surface treatment material are added via the use of an
apparatus for coating particles, such as powdery or granular
materials, as described in WO 97/07879 published Mar. 6, 1997, and
assigned to E.I. du Pont de Nemours and Company, or as described in
U.S. Pat. No. 4,430,001. Use of said apparatus for encapsulating
titanium dioxide particles with the organic surface treatment
material involves metering a liquid composition comprising the
organic surface treatment material, where the liquid composition is
either a solution, slurry, or melt, into a flow restrictor and
injecting a gas stream through the flow restrictor concurrently
with the metering of the liquid composition to create a zone of
turbulence at the outlet of the flow restrictor, thereby atomizing
the liquid composition. The gas stream can be heated if necessary.
Dried titanium dioxide particles substantially encapsulated with a
pyrogenically-deposited metal oxide can be added to the zone of
turbulence concurrently with the metering of the liquid composition
and the injection of the heated gas to mix the titanium dioxide
particles with the atomized liquid composition. Alternatively, said
titanium dioxide particles can be added downstream of the zone of
turbulence. The mixing at the zone of turbulence treats the
titanium dioxide particles with the organic surface treatment
material.
[0105] Pigments disclosed herein can be employed to readily and
uniformly fill a wide variety of thermoplastic resins, such as
those disclosed in U.S. Pat. No. 5,397,391. These include, but are
not limited to, such well known classes of thermoplastic resins as
polyolefin resins, acrylic resins, polyester resins, polyamide
resins, epoxy resins, phenolic resins, poly(vinylaromatic) resins,
poly(vinylhalide) resins, polycarbonate resins, fluoropolymer
resins, elastomeric polymer resins, polyurethaneurea resins,
polyurethane resins, polyacetal resins, polyimide resins,
polyetherimide resins, polyamideimide resins, polyetheretherketone
resins, polyetherketoneketone resins, liquid crystal polymer resins
and the like, and blends thereof. Representative, but non-limiting,
examples of these various classes of thermoplastic resins include
polyolefin resins such as polyethylene including, but not limited
to, polyethylene made with conventional, high activity and
metallocene-based catalyst systems such as, for example, ultra low
density polyethylenes (ULDPE), very low density polyethylenes
(VLDPE), linear low density polyethylenes (LLDPE), low density
polyethylenes (LDPE), medium density polyethylenes (MDPE), high
density polyethylenes (HDPE), high molecular weight high density
polyethylenes (HMWHDPE), ultra high molecular weight high density
polyethylenes (UHMWHDPE), ethylene/vinyl acetate (EVA) co-polymer,
ethylene/methacrylic acid (EMA) co-polymer, and blends thereof,
polypropylene including homopolymers, copolymers, compounded and in
situ thermoplastic olefins, and the like, and blends thereof;
acrylic resins such as poly(acrylic acid), poly(methacrylic acid),
poly(methylacrylate), poly(methylmethacrylate), and the like, and
blends thereof; polyester resins such as poly(ethylene
terephthalate), poly(butylene terephthalate),
poly(cyclohexylene-dimethyl- ene terephthalate), poly(trimethylene
terephthalate), poly(ethylene naphthalate), and the like, and
blends thereof; polyamide resins such as nylon 6, nylon 6,6, nylon
6/6,6 co-polymer, nylon 11, nylon 6,10, nylon 6,12, amorphous
nylon, and the like, and blends thereof; epoxy resins such as
poly(epichlorohydrin/bisphenol A) and the like and esters thereof
such as those prepared by the esterification of
poly(epichlorohydrin/bisp- henol A) with a fatty acid, resin acid,
tall oil acid or mixtures thereof; phenolic resins such as those
derived from the reaction of formaldehyde with phenol, resorcinol,
cresol, p-phenylphenol, and the like, and blends thereof;
poly(vinylaromatic) resins such as polystyrene and copolymers
thereof such as poly(styrene-acrylonitrile),
poly(acrylonitrile-styrene-b- utadiene),
poly(acrylonitrile-styrene-acetate), and the like, and blends
thereof; poly(vinylhalide) resins, such as poly(vinylchloride),
poly(vinylchloride/vinylidene chloride), and the like, and blends
thereof; polycarbonate resins such as those attained either by the
phosgenation of dihydroxy aliphatic or aromatic monomers such as
ethylene glycol, propylene glycol, bisphenol A (i.e.,
4,4'-isopropylidene diphenol), and the like or by the base
catalyzed transesterification of bisphenol A with dimethyl or
diphenyl carbonate to produce bisphenol A polycarbonate, and blends
thereof; fluoropolymer resins, such as
tetrafluoroethylene/perfluoro(propyl vinyl ether) (PFA) co-polymer,
polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF),
tetrafluoroethylene/hexafluoropropylene (FEP) co-polymer,
ethylene/tetrafluoroethylene/perfluorobutyl ethylene (EFTE)
ter-polymer, ethylene/chlorotrifluoroethylene (ECTFE) co-polymer,
and the like, and blends thereof; elastomeric polymer resins such
as natural rubber, synthetic rubber, acrylics, chlorosulfonated
polyethylene, neoprene, silicones, urethanes, and the like, and
blends thereof; polyurethaneurea resins such as polyether- and
polyester-based spandex, and the like, and blends thereof;
polyurethane resins obtained by the reaction of di- or
poly-functional hydroxy compounds such as glycols or hydroxyl
terminated polyesters and polyethers with di- or poly-isocyanate
containing compounds, and the like, such as, for example,
4,4'-dicyclohexylmethane diisocyanate (H12MDI), hexamethyl
diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene
diphenyl diisocyanate (MDI), toluene diisocyanate (TDI),
tetramethylxylene diisocyanate (TMXDI), o-tolidine diisocyanate
(TODI), 1,4-cyclohexane diisocyanate (CHDI), and blends thereof;
polyacetal resins such as polyformaldehyde, copolymers of
formaldehyde with cyclic ethers such as, for example, ethylene
oxide, 1,3-dioxolane, and the like, and blends thereof; polyimide
resins obtained by the reaction of an aromatic dianhydride such as
pyromellitic dianhydride with an aromatic diamine such as
p-phenylenediamine, and the like, and blends thereof;
polyetherimide resins obtained by the reaction of an aromatic
dianhydride such as pyromellitic dianhydride with an aromatic
diamine such as 4,4'-oxydianiline, and the like, and blends
thereof; polyamideimide resins obtained by the reaction of an
aromatic anhydride acid chloride such as trimellitic anhydride acid
chloride with an aliphatic diamine such as 1,4-cyclohexanediamine,
and the like, and blends thereof; polyetheretherketone resins
obtained by the reaction of an dihaloaromatic ketone such as
bis(4-chlorophenyl)ketone with an aromatic diol such as
hydroquinone, and the like, and blends thereof;
polyetherketoneketone resins obtained by the reaction of an
diaromatic ether such as diphenyl ether with an aromatic diacid
chloride such as terephthaloyl chloride, and the like, and blends
thereof; and liquid crystal polymer resins such as those as
described in U.S. Pat. No. 6,492,463, and the like, and blends
thereof.
[0106] Particles comprising compositions of the invention may be
used to fill thermoplastics in any of the customary ways such as,
for example, extrusion applications including, for example, cast
film extrusion, blown film extrusion, slit film extrusion, sheet
and profile extrusion, fiber and filament extrusion, and wire
coating extrusion; molded article applications including, for
example, injection molding, blow molding, and rotational molding;
and post-article forming coating applications such as, for example,
powder coating, roll-on coating, brush-on coating, trowel-on
coating, and spray-on coating.
[0107] In cast film extrusion, useful thermoplastics include, for
example, polyethylenes, polypropylenes, polyesters, polyvinyl
chlorides, styrenes, polyamides, and polycarbonates.
[0108] In blown film extrusion, useful thermoplastics include, for
example, polyethylenes and polypropylenes.
[0109] In slit film extrusion, useful thermoplastics include, for
example, polypropylenes.
[0110] In sheet and profile extrusion, useful thermoplastics
include, for example, polyethylenes, polypropylenes, polyesters,
polyvinyl chlorides, styrenes, fluoropolymers, polyamides,
polycarbonates, elastomeric polymers, polyimides, polyetherimides,
polyamideimides, polyetheretherketones, polyetherketoneketones,
polyphenylene sulfides, and polyacetals.
[0111] In fiber and filament extrusion, useful thermoplastics
include, for example, polypropylenes, polyesters, polyamides, and
polyurethaneureas and elastomeric polymers.
[0112] In wire coating extrusion, useful thermoplastics include,
for example, polyethylenes, polyvinyl chlorides, and
fluoropolymers, polyimides, polyetherimides, and elastomeric
polymers.
[0113] In injection molding, useful thermoplastics include, for
example, polyethylenes, polypropylenes, polyesters, polyvinyl
chlorides, styrenes, polyamides, polycarbonates, urethanes,
acetals, polyphenylene sulfides, elastomeric polymers, polyimides,
polyetherimides, polyamideimides, polyetheretherketones, and liquid
crystalline polymers.
[0114] In blow molding, useful thermoplastics include, for example,
polyethylenes, polypropylenes, polyesters, polyvinyl chlorides,
polyamides, and polycarbonates.
[0115] In rotational molding, useful thermoplastics include, for
example, polyethylenes and polypropylenes.
[0116] In post-article forming coatings, useful thermoplastics
include, for example, polyethylenes, polyvinyl chlorides,
fluoropolymers, elastomeric polymers, and urethanes.
[0117] All of the compositions and methods disclosed and claimed
herein can be made and executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this invention have been described in terms of preferred
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the compositions and methods and in
the steps or in the sequence of steps of the method described
herein without departing from the concept, spirit, and scope of the
invention. More specifically, it will be apparent that certain
agents which are chemically related may be substituted for the
agents described herein while the same or similar results would be
achieved. All such similar substitutes and modifications apparent
to those skilled in the art are deemed to be within the spirit,
scope, and concept of the invention as defined by the appended
claims.
[0118] In one embodiment, the invention herein can be construed as
excluding any element or process step that does not materially
affect the basic and novel characteristics of the composition or
process. Additionally, the invention can be construed as excluding
any element or process step not specified herein.
EXAMPLES
[0119] The present invention is further defined in the following
Examples. It should be understood that these Examples, while
indicating preferred embodiments of the invention, are given by way
of illustration only. From the above discussion and these Examples,
one skilled in the art can ascertain the preferred features of this
invention, and without departing from the spirit and scope thereof,
can make various changes and modifications of the invention to
adapt it to various uses and conditions.
[0120] The meaning of abbreviations is as follows: "h" means
hour(s), "min" means minute(s), "sec" means second(s), "mL" means
milliliter(s), "g" means gram(s), "psi" means pound(s) per square
inch, "wt %" means weight percent(age), "Pa" means Pascal, "TGA"
means thermogravimetric analysis, "OTES" means
octyltriethoxysilane, ".about." means approximately, "L" means
liters, ".degree. C." means degrees Celsius, "mil" means thousandth
of an inch, ".degree. F." means degrees Fahrenheit, ".degree. "
means degree(s), ".DELTA." means delta, "vol %" means volume
percent(age), "mm" means millimeter(s), "rpm" means revolutions per
minute, and "cm.sup.3" means cubic centimeter(s).
[0121] Standard Test Methods
[0122] Descriptions of the standard test methodologies utilized for
the physical characterization of the particles produced by the
current invention (except bulk density, see Example 11) are
provided below. More specifically:
[0123] Carbon analyses were performed on dry particle samples using
LECO CNS 2000 or C400 Analyzers (LECO Corporation, St. Joseph,
Mich.).
[0124] Dispersion analyses, as defined by particle retention on a
500 mesh screen, were performed on 50 wt % polyethylene (NA206,
Equistar) masterbatch concentrates (Farrel Banbury.RTM. BR1600
produced) containing the particles of interest. Said concentrates
were extruded (500 g; Killion 3/4 inch single screw extruder, Cedar
Grove, N.J.) through a sandwich of fine mesh, metal wire screens
(30, 60, 500, 60, 60, 60 mesh) which were then separated, and the
magnitude of particles retained on the 500 mesh screen determined
using x-ray fluorescence (9200 Series Portable Analyzer, Texas
Nuclear Corp., Austin, Tex.).
[0125] Vinyl based tint strength and undertone analyses were
performed on flexible polyvinylchloride (Coastal Plastics, Hope
Valley, R.I.) sheets containing carbon black (0.02 wt %; delivered
in dioctyl phthalate; Custom Chemical Co., Elmwood, N.J.) and the
particles of interest (3.16 wt %). Said sheets were produced with
the aid of a two-roll mill (Kobelco Stewart Boiling, Inc., Hudson,
Ohio) and were analyzed (along with a sheet comparably produced
using control titanium dioxide particles) colourimetrically using a
Hunter Lab Labscan XE (D65 light source; Hunter Associates
Laboratory, Inc., Reston, Va.) for their X, Y and Z tristimulus
values which were then converted to tint strength and undertone
values via Kubelka-Monk methodology.
[0126] Analyses for median particle size were performed on
sonicated (Sonicator Ultrasonic Liquid Processor Model XL 2020,
Heat Systems, Inc., Farmingdale, N.Y.) 3 wt % solids slurries (made
up in a 0.2 g/L tetrapotassium pyrophosphate solution) using a
Horiba LA-900 laser light-scattering, particle size analyzer
(Horiba Instruments, Inc., Irvine, Calif.).
[0127] Colour analyses (Commission Internationale de I'Eclairage
L*a*b* color coordinates) were performed on compressed solid cakes
of particles using a Hunter Lab Labscan XE (10.degree. observer
angle, D65 light source; Hunter Associates Laboratory, Inc.,
Reston, Va.).
Example 1
[0128] Approximately 10 metric tons of pigmentary sized titanium
dioxide particles (rutile crystalline phase) substantially
encapsulated with about 2.0 wt % pyrogenic silica were produced
using commercial scale equipment according to the teaching of U.S.
Patent Publication No. 2003/0051635. An acidic, aqueous slurry of
this material (.about.380 g/L) was adjusted to a pH value of
.about.8 (sodium hydroxide) and the residual chlorine present in
said slurry neutralized. Said slurry was then acidified temporarily
to pH 6 (sulfuric acid), subsequently re-adjusted to pH 8.5 (sodium
hydroxide) and finally filtered (rotary drum filter). The produced
filter cake was removed from the filter apparatus and dropped onto
a conveying screw where neat octyltriethoxysilane (OTES) was added
to said cake by peristaltic pump. The resulting pigment/OTES
mixture was then fed directly to a spray dryer. The resultant dried
product (dryer exit temperature .about.100.degree. C.) was then
pneumatically conveyed to a fluid energy mill (steam micronizer)
where it was subjected to de-agglomeration and subsequently
packaged. The resulting material (analyzed in .about.1 metric ton
increments) possessed OTES-derived carbon values ranging from 0.19
to 0.37 wt %.
Example 2
[0129] Approximately 55 metric tons of pigmentary sized titanium
dioxide particles (rutile crystalline phase) substantially
encapsulated with about 1.5 wt % pyrogenic silica were produced
using commercial scale equipment according to the teaching of U.S.
patent Publication No. 2003/0051635. An acidic, aqueous slurry of
this material (.about.350 g/L) was adjusted to a pH value of 4.7
(sodium hydroxide) and the residual chlorine present in said slurry
neutralized. Said slurry was then filtered using a press plate
filter at pH values between 4.0 (pH reductions performed using
hydrochloric acid) and 5.1 (pH increases performed using sodium
hydroxide). The produced filter cake was conveyed to a flash dryer
where said cake was simultaneously dried and treated with varying
amounts of neat octyltriethoxysilane (OTES) which was injected
directly into the dryer body. The resultant dried product (dryer
exit temperature .about.120.degree. C.) was then conveyed to a
fluid energy mill (steam micronizer) where it was subjected to
de-agglomeration and subsequently packaged. The resulting material
(analyzed in .about.5 metric ton increments) possessed OTES-derived
carbon values ranging from 0.29 to 0.32 wt %. An additional
.about.260 metric tons of OTES-treated material was produced as
described above with the exception that the OTES was added to the
dry pigment just prior to said pigment entering the steam
micronizer. Material produced using this latter procedure (again
analyzed in .about.5 metric ton increments) possessed OTES-derived
carbon values ranging from 0.26 to 0.38 wt %.
Example 3
[0130] Approximately 194 metric tons of pigmentary sized titanium
dioxide particles (rutile crystalline phase) substantially
encapsulated with about 2.0 wt % pyrogenic silica were produced
using commercial scale equipment according to the teaching of U.S.
patent Publication No. 2003/0051635. An acidic, aqueous slurry of
this material (.about.350 g/L) was adjusted to a pH value of 8.0
(sodium hydroxide) and the residual chlorine present in said slurry
neutralized. Said slurry was then filtered using a press plate
filter at pH values between 4.5 (pH reductions performed using
hydrochloric acid) and 8.8 (pH increases performed using sodium
hydroxide). The produced filter cake was conveyed to a flash dryer
where said cake was simultaneously dried and treated with varying
amounts of neat trimethylolpropane (TMP), which was injected
directly into the dryer body. The resultant dried product (dryer
exit temperature .about.120.degree. C.) was then conveyed to a
fluid energy mill (steam micronizer) where it was subjected to
de-agglomeration and subsequently packaged. The resulting material
(analyzed in .about.5 metric ton increments) possessed TMP-derived
carbon values ranging from 0.12 to 0.29 wt %. The dried product was
also found to possess an average silica (SiO.sub.2) content of
about 1.3 wt % and not the larger value (see above) determined for
the titanium particles prior to their TMP treatment. This reduction
in silica content was attributed to an inadvertent contamination of
the aqueous slurry of the pyrogenic silica-encapsulated titanium
dioxide particles with slurry containing titanium dioxide particles
that did not possess said encapsulation.
Example 4
[0131] Approximately 337 metric tons of pigmentary sized titanium
dioxide particles (rutile crystalline phase) substantially
encapsulated with about 2.0 wt % pyrogenic silica were produced
using commercial scale equipment according to the teaching of U.S.
patent Publication No. 2003/0051635. An acidic, aqueous slurry of
this material (.about.350 g/L) was adjusted to a pH value of 6.5
(sodium hydroxide) and the residual chlorine present in said slurry
neutralized. Said slurry was then filtered using a press plate
filter at pH values between 3.7 (pH reductions performed using
hydrochloric acid) and 4.5 (pH increases performed using sodium
hydroxide). The produced filter cake was conveyed to a flash dryer
where said cake was simultaneously dried and treated with neat
OTES, which was injected directly into the dryer body. The
resultant dried product (dryer exit temperature .about.120.degree.
C.) was then conveyed to a fluid energy mill (steam micronizer)
where it was subjected to de-agglomeration and subsequently
packaged. Standard characterization of the resulting material
(analyzed in .about.20 metric ton increments) yielded the data
provided in Table 1:
1 TABLE 1 Analysis Data Range OTES-derived carbon 0.30-0.37 wt %
Screen pack dispersion, 13-35 500 mesh (50 wt % masterbatch) Vinyl
tint strength 107-111 Vinyl undertone 0.030-0.038 Median particle
size 0.295-0.333 microns Dry colour L* 99.0-99.6 Dry colour a*
-0.50--0.64 Dry colour b* 1.6-2.2
Example 5
[0132] Product collected from Examples 1 and 2, as well as a
control sample derived from an OTES-treated, non-silica-containing
commercial product (yellowing control), were evaluated for their
resistance to stabilizer derived yellowing using an in-house
version of the Toyo Test, the results from which are presented in
Table 2. Said test involved individually compounding said products
into DuPont 20 polyethylene (low density polyethylene) along with
butylated hydroxytoluene (BHT) and Tinuvin.RTM. 770 (Ciba Specialty
Chemicals, Tarrytown, N.Y.) using a standard two-roll milling
procedure (35 mil roller gap, 220.degree. F. (104.4.degree. C.) and
240.degree. F. (115.6.degree. C.) roller temperatures). The
resulting thick films (2.6 wt % pigment, 0.3 wt % BHT, 0.3 wt %
Tinuvin.RTM. 770) were then hot pressed (.about.325-350.degree. F.
(.about.162.8-176.7.degree. C.), .about.50,000 psi (.about.3516.2
kg/cm.sup.2) for .about.2 minutes) into plaques using a pre-made
template. The initial CIE (Commission Internationale de
I'Eclairage) L*a*b* color coordinates of the plaques were then
measured (Hunter Lab Labscan XE, 10.degree. observer angle, D65
light source) and the plaques subsequently placed into an enclosed,
ultraviolet light source-containing light box (not temperature
controlled). Said plaques were then periodically removed
(approximately every 1-2 days) and their CIE L*a*b* color
coordinates re-obtained. A consistent rotation scheme was utilized
when said plaques were placed back into the light box for continued
exposure. After .about.218 hours of exposure, the .DELTA.b* value
associated with each sample was normalized against that of the
control sample which yellows significantly under the conditions of
this test (.DELTA.b* Sample/.DELTA.b*Control).
2TABLE 2 Calculated OTES- Pyrogenic Derived .DELTA.b* Sample/
SiO.sub.2 Carbon .DELTA.b* Control after Content Content Of
.about.218 exposure Sample Of Sample Sample hours
Non-silica-containing, 0.0 wt % Typically 0.30 1.00 OTES-treated
TiO.sub.2: wt % (by Yellowing Control (dryer added) definition)
OTES-treated, 1.5 wt % 0.31 wt % 0.13 pyrogenic silica- (dryer
added) encapsulated TiO.sub.2: Sample 1 OTES-treated, .about.2.0 wt
% 0.36 wt % 0.02 pyrogenic silica- (slurry added) encapsulated
TiO.sub.2: Sample 2 OTES-treated, .about.2.0 wt % 0.26 wt % 0.07
pyrogenic silica- (slurry added) encapsulated TiO.sub.2: Sample 3
OTES-treated, 1.4 wt % 0.30 wt % 0.20 pyrogenic silica- (micronized
encapsulated added) TiO.sub.2: Sample 4 OTES-treated, 1.3 wt % 0.35
wt % 0.21 pyrogenic silica- (micronizer encapsulated added)
TiO.sub.2: Sample 5 OTES-treated, 1.3 wt % 0.36 wt % 0.12 pyrogenic
silica- (micronizer encapsulated added) TiO.sub.2: Sample 6
[0133] The data in Table 2 reveal that all of the pyrogenic
silica-encapsulated, OTES-treated samples (Samples 1 through 6)
possess significantly greater stabilizer derived discolouration
resistance relative to the OTES-treated, non-silica-containing,
yellowing control sample. This finding has favourable practical
implications as it suggests that the product of this invention can
be incorporated into polymeric systems possessing a broad range of
polymer additives (including stabilizers) without a concern for the
occurrence of deleterious, ultraviolet light-driven,
discolouration. That said finding is a direct result of the
pyrogenic silica encapsulation can be logically inferred from the
fact that the only important difference between Sample 1 and the
yellowing control sample is that the former possesses a significant
quantity of particle encapsulating pyrogenic silica while the
latter does not (both sets of samples possess comparable levels of
OTES-derived carbon, applied in identical fashion).
Example 6
[0134] Product collected from Examples 1 and 2, as well as control
samples derived from an OTES-treated, non-silica-containing
commercial product (non-lacing control) and from a non-OTES
treated, amorphous alumina-containing commercial product (lacing
control), were evaluated for their thin film lacing propensity
using an in-house developed test. Said test involved individually
compounding the above indicated products into polyethylene (NA206,
Equistar) using a batch internal mixer (Farrel Banbury.RTM. BR1600)
at a 50 wt % product loading (76 vol % fill factor). The resulting
masterbatches were then ground into small pieces and individually
combined by hand with fresh low density polyethylene (DuPont 20) to
yield 20 wt % product mixtures which were then dried overnight
(88.degree. C.) in air. Each of the prepared mixtures was then
converted (400 g per conversion) into a thin ribbon (.about.1.0-1.5
mil (.about.0.0254-0.0381 mm) thick, .about.23/4 inches
(.about.6.985 cm) wide) using a single screw extruder. The
temperature of the film extrudate was .about.610.degree. F.
(.about.321.1.degree. C.). After cooling, the extruded ribbons were
then examined for signs of lacing using the rating scheme presented
in Table 3.
3TABLE 3 Lacing Test Rating Description .sup. 10+ No indications of
a pre-lacing condition (dark striations) or lacing (elongated thin
spots or holes). 10 No elongated thin spots or holes, but
pre-lacing signs are present. 8 Presence of a few very small
elongated thin spots or holes. 6 Presence of numerous small
elongated thin spots or holes. 4 Presence of numerous large
elongated thin spots or holes. 2 Total film is covered with
elongated holes. 0 Film break is caused by complete loss of film
integrity.
[0135] Data from said examination is presented in Table 4.
4TABLE 4 Calculated OTES-Derived Lacing Pyrogenic SiO.sub.2 Carbon
Content Test Sample Content Of Sample Of Sample Rating
Non-silica-containing, 0.0 wt % Typically 0.30 10+.sup.
OTES-treated TiO.sub.2: wt % Non-Lacing Control (dryer added) Wet
treatment 0.0 wt % Typically 0.19 alumina- (alumina derived wt %
.sup. 4 encapsulated encapsulation only) (non-OTES TiO.sub.2:
Lacing Control derived) OTES-treated, 1.5 wt % 0.31 wt % 10+.sup.
pyrogenic silica- (dryer added) encapsulated TiO.sub.2: Sample 1
OTES-treated, 1.4 wt % 0.30 wt % 10+.sup. pyrogenic silica-
(micronized encapsulated added) TiO.sub.2: Sample 2 OTES-treated,
1.3 wt % 0.35 wt % 10+.sup. pyrogenic silica- (micronizer
encapsulated added) TiO.sub.2: Sample 3 OTES-treated, 1.3 wt % 0.36
wt % 10+.sup. pyrogenic silica- (micronizer encapsulated added)
TiO.sub.2: Sample 4 OTES-treated, .about.2.0 wt % 0.36 wt %
10+.sup. pyrogenic silica- (slurry added) encapsulated TiO.sub.2:
Sample 5 OTES-treated, .about.2.0 wt % 0.35 wt % 10+.sup. pyrogenic
silica- (slurry added) encapsulated TiO.sub.2: Sample 6
[0136] The data in Table 4 reveal that all of the masterbatch
samples derived from the pyrogenic silica-encapsulated,
OTES-treated samples (Samples 1 through 6) did not lace. This
finding has favourable practical implications as it suggests that
the product of this invention can be incorporated into thin polymer
films at high pigment loading under severe extrusion conditions
without a concern for lacing-derived film damage.
Example 7
[0137] Product collected from Examples 1 and 2, as well a control
sample derived from an OTES-treated, non-silica-containing
commercial product (non-photodurable control), were evaluated for
their photodurability behaviour (550 exposure hours) using an
in-house developed gloss retention test, the results from which are
presented in Table 5. Said test involved individually compounding
the above indicated products into polyethylene (NA206, Equistar)
using a batch internal mixer (Farrel Banbury.RTM. BR1600) at a 50
wt % pigment loading (76 vol % fill factor). The resulting
masterbatches were ground into small pieces and then individually
let down at 420.degree. F. (215.6.degree. C.) to 10 wt % TiO.sub.2
with injection molding grade polypropylene (Montell PH-920S) using
a Cincinnati-Milacron (Vista VT85-7) injection molder. The
molder-produced 13/4 inches.times.3 inches.times.1/8 inch (4.45
cm.times.7.62 cm.times.0.318 cm) chips were analyzed for initial
gloss (average of readings from the top, middle and bottom of the
to-be-exposed side of each chip) using a Byk-Gardener Gloss-Haze
meter. Said chips were then weathered in an Atlas Ci65A xenon
Weather-Ometer.RTM. in accordance with ASTM Method G26-92 (Annual
Book of ASTM Standards, Volume. 6.01, G26-92, 310-318, (1999)). To
eliminate water spotting, water with a minimum resistance of 12
megaohms was used. At periodic intervals, the chips were removed
from the Weather-Ometer.RTM., dried, and re-analyzed for surface
gloss retention, loss of which results from the product-catalyzed
photo-degradation of the chip polymer matrix (greater gloss
retention equates with greater photo-durability).
5TABLE 5 Calculated % Gloss Pyrogenic OTES-Derived Retention After
SiO.sub.2 Content Carbon Content 550 Exposure Sample Of Sample Of
Sample Hours Non-silica-containing, 0.0 wt % Typically 0.30 48.3
OTES-treated TiO.sub.2: wt % Non-Photodurable (dryer added) Control
OTES-treated, 1.5 wt % 0.31 wt % 64.0 pyrogenic silica- (dryer
added) encapsulated TiO.sub.2: Sample 1 OTES-treated, 1.4 wt % 0.30
wt % 62.0 pyrogenic silica- (micronized encapsulated added)
TiO.sub.2: Sample 2 OTES-treated, 1.3 wt % 0.35 wt % 61.5 pyrogenic
silica- (micronizer encapsulated added) TiO.sub.2: Sample 3
OTES-treated, 1.3 wt % 0.36 wt % 61.2 pyrogenic silica- (micronizer
encapsulated added) TiO.sub.2: Sample 4 OTES-treated, .about.2.0 wt
% 0.36 wt % 71.5 pyrogenic silica (slurry added) encapsulated
TiO.sub.2: Sample 5 OTES-treated, .about.2.0 wt % 0.35 wt % 71.4
pyrogenic silica- (slurry added) encapsulated TiO.sub.2: Sample
6
[0138] The data in Table 5 reveal that all of the
polyethylene/polypropyle- ne composite chips containing the
pyrogenic silica-encapsulated, OTES-treated samples (Samples 1
through 6) exhibited significantly higher gloss retention after
exposure (in other words, significantly better photodurability) as
compared to the chip containing the OTES-treated,
non-silica-containing, non-photodurable control sample. This
finding has favourable practical implications given that the
photo-passivation of TiO.sub.2 particles is typically accomplished
via an aqueous-based, surface deposition of inorganic oxides,
treatments which are characteristically prone to moisture retention
and/or generation which contribute to thin film lacing. Such
treated particles cannot be reliably used for high temperature,
thin film extrusion applications, unlike particles resulting from
the current invention (see Example 6). That said finding is a
direct result of the pyrogenic silica encapsulation can be
logically inferred from the fact that the only important difference
between Sample 1 and the non-photodurable control sample is that
the former possesses a significant quantity of particle
encapsulating pyrogenic silica while the latter does not (both sets
of samples possess comparable levels of OTES-derived carbon,
applied in identical fashion).
Example 8
[0139] Product collected from Examples 1 and 2, as well as control
samples derived from an OTES-treated, but non-silica-containing
commercial product (high processing rate control), were evaluated
for their effect on the melt viscosity of highly loaded
masterbatch. Said masterbatches were prepared by individually
compounding the above indicated products into polyethylene (NA206,
Equistar) using a batch internal mixer (Farrel Banbury.RTM. BR1600)
at an 80 wt % pigment loading (74 vol % fill factor). An .about.650
g sample of each of the produced masterbatches was then degassed,
while still hot, by repeatedly (5 times) running it through a
two-roll mill (35 mil roller gap, 220.degree. F. (104.4.degree. C.)
and 240.degree. F. (115.6.degree. C.) roller temperatures). The
resulting thick films were cut into slivers (.about.35
mil.times..about.1/4 inch.times.2 inch (.about.0.89
mm.times..about.0.64 cm.times.5.08 cm)) which were then dried
overnight in a vacuum oven (204.degree. C., nitrogen purge).
Appropriate amounts of the dried slivers were then fed into a
Dynisco LCR7001 Capillary Rheometer (die type=X400-15, capillary
diameter=0.0400 inch (1.02 mm), L/D=15.00, entrance
angle=120.degree., capillary length=0.6000 inch (1.52 cm)) and
their melt viscosity versus shear rate behavior (10-1000
sec.sup.-1) determined at 190.degree. C. Calculated (from curve
fitting) low shear rate (10 sec.sup.-1) masterbatch melt viscosity
data associated with product derived from Example 1 are presented
in Table 6 while said data associated with product derived from
Example 2 are presented in Table 7.
6TABLE 6 Calculated Calculated Masterbatch Pyrogenic OTES-Derived
Melt Viscosity SiO.sub.2 Content Carbon Content (190.degree. C.,
Sample Of Sample Of Sample 10 sec.sup.-1) Non-silica-containing,
0.0 wt % Typically 0.30 2951 Pa-sec OTES-treated TiO.sub.2: wt %
High Processing Rate (dryer added) Control 1 Non-silica-containing,
0.0 wt % Typically 0.30 3177 Pa-sec OTES-treated TiO.sub.2: wt %
High Processing Rate (dryer added) Control 2 OTES-treated,
.about.2.0 wt % 0.24 wt % 3128 Pa-sec pyrogenic silica- (slurry
added) encapsulated TiO.sub.2: Sample 1 OTES-treated, .about.2.0 wt
% 0.31 wt % 2680 Pa-sec pyrogenic silica- (slurry added)
encapsulated TiO.sub.2: Sample 2 OTES-treated, .about.2.0 wt % 0.32
wt % 2522 Pa-sec pyrogenic silica- (slurry added) encapsulated
TiO.sub.2: Sample 3 OTES-treated, .about.2.0 wt % 0.33 wt % 2464
Pa-sec pyrogenic silica- (slurry added) encapsulated TiO.sub.2:
Sample 4
[0140]
7TABLE 7 Calculated Calculated Masterbatch Pyrogenic OTES-Derived
Melt Viscosity SiO.sub.2 Content Carbon Content (190.degree. C.,
Sample Of Sample Of Sample 10 sec.sup.-1) Non-silica-containing,
0.0 wt % Typically 0.30 2483 Pa-sec OTES-treated TiO.sub.2: wt %
High Processing Rate (dryer added) Control 3 Non-silica-containing,
0.0 wt % Typically 0.30 2662 Pa-sec OTES-treated TiO.sub.2: wt %
High Processing Rate (dryer added) Control 4 OTES-treated, 1.5 wt %
0.31 wt % 2559 Pa-sec pyrogenic silica- (dryer added) encapsulated
TiO.sub.2: Sample 5 OTES-treated, 1.4 wt % 0.30 wt % 2493 Pa-sec
pyrogenic silica- (micronized encapsulated added) TiO.sub.2: Sample
6 OTES-treated, 1.3 wt % 0.35 wt % 2332 Pa-sec pyrogenic silica-
(micronizer encapsulated added) TiO.sub.2: Sample 7 OTES-treated,
1.3 wt % 0.36 wt % 2423 Pa-sec pyrogenic silica- (micronizer
encapsulated added) TiO.sub.2: Sample 8
[0141] The data in Table 6 reveal that all of the masterbatches
produced with the pyrogenic silica-encapsulated, OTES-treated
samples involving slurry addition of OTES (Samples 1 through 4)
possessed low shear rate melt viscosity values either comparable to
or unexpectedly less than that derived from the masterbatches
containing the OTES-treated, non-silica-containing, high processing
rate control samples (Controls 1 and 2). The data in Table 7 show
that similar behaviour is displayed by the masterbatches derived
from the pyrogenic silica-encapsulated, OTES-treated samples
involving dryer and micronizer addition of OTES (Samples 5 through
8, compared against Controls 3 and 4). The above aggregate findings
have favourable practical implications as they suggest that the
product of this invention can be incorporated into masterbatch at
high loadings without a concern for the occurrence of undesirable
masterbatch processing rate restrictions.
Example 9
[0142] Product collected from Example 2, as well as a control
sample derived from an OTES-treated, non-silica-containing
commercial product (high processing rate control), were evaluated
for their effect on the melt flow rate of highly loaded
masterbatch. Said masterbatches were prepared by individually
compounding the above indicated products into polyethylene (NA206,
Equistar) at a 70 wt % product loading using a 30 mm co-rotating
twin screw extruder (Werner and Pfleiderer) set up to extrude
masterbatch at 50, 60 and 70 pound/hour (22.7, 27.2 and 31.8
kg/hour) rates (300 rpm screw speed, all barrel temperature
controllers set to 150.degree. C). A general purpose screw design
was used as was standard post-compounding equipment consisting of a
strand die, a cooling water trough and an air knife pelletizer.
Neither screens nor breaker plates were employed during the
compounding runs. The produced masterbatch pellets (as well as
pellets of the unpigmented resin used to make the above described
masterbatches) were vacuum dried under a nitrogen purge
(204.degree. C., 12 hours) prior to their analysis for melt flow
rate. Said analysis was carried out at 190.degree. C. using a
Dynisco Kayeness Model D4004 melt indexer in accordance with ASTM
Method D-1238 Condition 190/2.160 (360 seconds preheat time, sample
cuts taken at 15 second intervals). The resulting data is presented
in Table 8.
8TABLE 8 Melt Calculated OTES-Derived Flow Pyrogenic Carbon
Masterbatch Rate SiO.sub.2 Content Content Of Throughput
(190.degree. Sample Of Sample Sample (lb/hour) C.) Unpigmented --
-- -- 13.4 NA206 polyethylene Non-silica- 0.0 wt % Typically 0.30
50 4.3 containing, wt % OTES-treated (dryer added) TiO.sub.2: High
Processing Rate Control 1 OTES-treated, 1.5 wt % 0.31 wt % 50 5.6
pyrogenic (dryer added) silica- encapsulated TiO.sub.2: Sample 1
Non-silica- 0.0 wt % Typically 0.30 60 4.3 containing, wt %
OTES-treated (dryer added) TiO.sub.2: High Processing Rate Control
1 OTES-treated, 1.5 wt % 0.31 wt % 60 5.8 pyrogenic (dryer added)
silica- encapsulated TiO.sub.2: Sample 1 Non-silica- 0.0 wt %
Typically 0.30 70 4.7 containing, wt % OTES-treated (dryer added)
TiO.sub.2: High Processing Rate Control 1 OTES-treated, 1.5 wt %
0.31 wt % 70 6.0 pyrogenic (dryer added) silica- encapsulated
TiO.sub.2: Sample 1
[0143] The data in Table 8 reveal that, independent of their
production rate, the masterbatches produced with the pyrogenic
silica-encapsulated, OTES-treated sample (Sample 1) possessed
noticeably higher melt flow rate values relative to those of the
masterbatch produced using the OTES-treated, non-silica-containing,
high processing rate control sample (Control 1). This unexpected
finding has favourable practical implications as it suggests that
the product of this invention can be incorporated into masterbatch
at high loadings without a concern for the occurrence of
undesirable masterbatch processing rate restrictions. Further
evidence in this regard is provided in Example 10. That said
finding is a direct result of the pyrogenic silica-encapsulation
can be logically inferred from the fact that the only important
difference between Sample 1 and the high processing rate control
sample is that the former possesses a significant quantity of
particle encapsulating pyrogenic silica while the latter does not
(both sets of samples possess comparable levels of OTES-derived
carbon, applied in identical fashion).
Example 10
[0144] Product collected from Examples 1 and 2, as well as a
control sample derived from an OTES-treated, non-silica-containing
commercial product (high processing rate control), were evaluated
for their effect on the melt flow rate of highly loaded
masterbatch. Said masterbatches were prepared by individually
compounding the above indicated products into polyethylene (NA206,
Equistar) at an 80 wt % product loading using a Thermo Haake
Rheomix 600p internal mixer (Thermo Electron Corporation) fitted
with a pair of Banbury Mixer-type rotors (110.degree. C. mixer
pre-heat temperature; 200 rpm initial rotor speed, decreased to 120
rpm once the masterbatch temperature reached 130.degree. C.; 10
minutes total compounding time). The resulting masterbatches were
ground into small pieces prior to their analysis for melt flow
rate. Said analysis was carried out at 190.degree. C. using a
Dynisco Kayeness Model 7053 melt indexer in accordance with ASTM
Method D-1238 Condition 190/2.160 (360 seconds preheat time, sample
cuts taken at 30 second intervals). The resulting data is presented
in Table 9.
9TABLE 9 Calculated Pyrogenic OTES-Derived SiO.sub.2 Content Carbon
Content Melt Flow Sample Of Sample Of Sample Rate (190.degree. C.)
Unpigmented -- -- 13.6 NA206 (average of 2 polyethylene
determinations) Non-silica- 0.0 wt % Typically 0.30 1.7 containing,
OTES- wt % (average of 4 treated TiO.sub.2: High (dryer added)
determinations) Processing Rate Control 1 OTES-treated, 1.5 wt %
0.31 wt % 2.4 pyrogenic silica- (dryer added) (average of 4
encapsulated determinations) TiO.sub.2: Sample 1 OTES-treated, 1.3
wt % 0.36 wt % 2.9 pyrogenic silica- (micronizer (average of 4
encapsulated added) determinations) TiO.sub.2: Sample 2
OTES-treated, 1.3 wt % 0.35 wt % 2.5 pyrogenic silica- (micronizer
(average of 4 encapsulated added) determinations) TiO.sub.2: Sample
3 OTES-treated, 1.4 wt % 0.30 wt % 2.1 pyrogenic silica-
(micronizer (average of 4 encapsulated added) determinations)
TiO.sub.2: Sample 4 OTES-treated, .about.2.0 wt % 0.36 wt % 2.1
pyrogenic silica- (slurry added) (average of 2 encapsulated
determinations) TiO.sub.2: Sample 5
[0145] The data in Table 9 reveal that all of the masterbatches
produced with the pyrogenic silica-encapsulated, OTES-treated
samples (Samples 1 through 5) possessed noticeably higher melt flow
rate values relative to that associated with the masterbatch
produced using the OTES-treated, non-silica-containing, high
processing rate control sample (Control 1). This unexpected finding
has favourable practical implications as it suggests that the
product of this invention can be incorporated into masterbatch at
high loadings without a concern for the occurrence of undesirable
masterbatch processing rate restrictions. That said finding is a
direct result of the pyrogenic silica encapsulation can be
logically inferred from the fact that the only important difference
between Sample 1 and the high processing rate control sample is
that the former possesses a significant quantity of particle
encapsulating pyrogenic silica while the latter does not (both sets
of samples possess comparable levels of OTES-derived carbon,
applied in identical fashion).
Example 11
[0146] Product collected from Example 2, as well as control samples
derived from an OTES-treated, non-silica-containing commercial
product (hydrophobic product control), had their loose and tapped
bulk density values determined, see Table 10, using in-house
developed methodology. Said methodology involved an initial hand
sieving of product through a 10 mesh sieve over a tared pan until
said pan was overfilled. Excess product above the rim of the pan
was then carefully and uniformly removed using a large spatula
blade held at a 45.degree. angle (from horizontal), taking care not
to jostle the contents of the pan. The pan was then weighed to
determine the amount of product added and the loose bulk density
calculated (pan volume=150.58 cm.sup.3). A plastic extension ring
was next carefully added to the pan. The extra volume afforded by
said ring was almost completely filled with additional product,
added using a metal spoon. The wooden handle end of a large spatula
was then used to hand tap the underside of the pan at its center
point using the same force for each tap. After 50 taps, the plastic
extension ring was carefully removed and the excess product above
the rim of the pan removed as described above. The pan was then
re-weighed to determine the amount of product present and the
tapped bulk density calculated.
10TABLE 10 Calculated OTES- Pyrogenic Derived SiO.sub.2 Carbon
Loose Tapped Content Content Of Bulk Bulk Sample Of Sample Sample
Density Density Non-silica-containing, 0.0 wt % Typically 0.30 0.77
1.17 OTES-treated TiO.sub.2: wt % g/mL g/mL Hydrophobic Pigment
(dryer added) Control 1 Non-silica-containing, 0.0 wt % Typically
0.30 0.76 1.22 OTES-treated TiO.sub.2: wt % g/mL g/mL Hydrophobic
Pigment (dryer added) Control 2 OTES-treated, 1.5 wt % 0.31 wt %
0.87 1.41 pyrogenic silica- (dryer added) g/mL g/mL encapsulated
TiO.sub.2: Sample 1 OTES-treated, 1.4 wt % 0.30 wt % 0.83 1.25
pyrogenic silica- (micronized g/mL g/mL encapsulated added)
TiO.sub.2: Sample 2 OTES-treated, 1.3 wt % 0.35 wt % 0.90 1.34
pyrogenic silica- (micronizer g/mL g/mL encapsulated added)
TiO.sub.2: Sample 3 OTES-treated, 1.3 wt % 0.36 wt % 0.91 1.33
pyrogenic silica- (micronizer g/mL g/mL encapsulated added)
TiO.sub.2: Sample 4
[0147] The data in Table 10 reveal that the loose and tapped bulk
densities of the pyrogenic silica-encapsulated, OTES treated
samples (Samples 1 through 4) are greater than those associated
with the OTES-treated, non-silica-containing, hydrophobic control
sample group (Controls 1 and 2). This unexpected finding has
favourable practical implications given that increased product bulk
density tends to result in increased throughput during commercial
scale polymer compounding. That said finding is a direct result of
the pyrogenic silica encapsulation can be logically inferred from
the fact that the only important difference between Sample 1 and
the control samples is that the former possesses a significant
quantity of particle encapsulating pyrogenic silica while the
latter do not (both sets of samples possess comparable levels of
OTES-derived carbon, applied in identical fashion).
* * * * *