USOO8436077B2

(12) United States Patent (10) Patent No.: US 8.436,077 B2 El-Shoubary (45) Date of Patent: May 7, 2013

(54) LIPID-TREATED PARTICLES AND 2003/0O29.359 A1 2/2003 Marshall et al. 2005/0228112 A1* 10/2005 Takahashi et al...... 524,497 POLYMERS CONTAINING THE PARTICLES 2006/0047021 A1* 3/2006 Craig et al...... 523,210 2006/01 11473 A1* 5/2006 Yuan et al...... 523,210 (75) Inventor: Modasser El-Shoubary, Crofton, MD (US) FOREIGN PATENT DOCUMENTS EP O535972 A1 4f1993 (73) Assignee: Cristal USA Inc., Hunt Valley, MD (US) EP 0628.303 A1 12, 1994 WO WO90-06103 6, 1990 (*) Notice: Subject to any disclaimer, the term of this WO WO93-11742 6, 1993 patent is extended or adjusted under 35 OTHER PUBLICATIONS U.S.C. 154(b) by 482 days. “File:Triglyceride-GeneralStructure.png; printed from Wikipedia website: http://en.wikipedia.org/wiki/File:Triglyceride (21) Appl. No.: 12/639,583 GeneralStructure.png; Oct. 28, 2009; 2 pages. 1-1. “Vegetable fats and oils”: printed from Wikipedia website: http://en. (22) Filed: Dec. 16, 2009 wikipedia.org/wiki/Vegetable oil; Oct. 28, 2009; 10 pages. "List of vegetable oils”: printed from Wikipedia website: http://en. (65) Prior Publication Data wikipedia.org/wiki/List of vegetable oils; Nov. 20, 2009; 16 US 2011/014.4251A1 Jun. 16, 2011 pageS. * cited by examiner (51) Int. Cl. CSK 9/00 (2006.01) Primary Examiner — Vickey Nerangis CSK 3/22 (2006.01) (74) Attorney, Agent, or Firm — Dunlap Codding, P.C.; (52) U.S. Cl. Tanzina Chowdhury USPC ...... 523/200; 523/210,524/497; 524/570 (58) Field of Classification Search ...... 523/200, (57) ABSTRACT 523/2 10. 524/497 A coated particulate Solid composition includes a particulate See application file for complete search history. inorganic solid having deposited on its surface a treatment oil comprising lipids. The particulate inorganic solid can include (56) References Cited a base particle of titanium dioxide, Zinc sulfide, Zinc oxide, iron oxide, lead oxide, aluminum oxide, silicon dioxide, Zir U.S. PATENT DOCUMENTS conium oxide and/or chromium oxide. The treatment oil is 4,061503 A 12/1977 Berger et al. optionally a vegetable oil. The treatment oil containing lipids 4,810,305 A 3, 1989 Braun et al. optionally contains glycerides such as triglycerides, and dig 5,188,831 A 2f1993 Nicollet al. lycerides, and can contain phospholipids. In one embodi 5,260,353 A * 1 1/1993 Palmer et al...... 523, 200 ment, the coated particulate Solid composition includes par 5,891.237 A 4/1999 Kinniard 6,620,234 B1 9, 2003 Kostelnik et al. ticulate titanium dioxide, wherein the treatment oil provides 6,646,037 B1 1 1/2003 El-Shoubary et al. increased bulk density, and enhanced dispersibility in plastic 6,765,041 B1 7/2004 El-Shoubary et al. as well as improved lacing resistance. 7,259,195 B2 8/2007 El-Shoubary et al. 7,601,780 B2 10/2009 Bell et al. 19 Claims, No Drawings US 8,436,077 B2 1. 2 LPD-TREATED PARTICLES AND and/or filled paints and plastics, and in reinforced plastic POLYMERS CONTAINING THE PARTICLES composite compositions. Also, U.S. Pat. No. 4,810.305 dis closes hydrophobic pigments and fillers obtained by Surface CROSS REFERENCE TO RELATED treatment with polydimethylsiloxanes and with specific orga APPLICATIONS nopolysiloxanes. While there has been much research regarding the coating Not applicable. of titanium dioxide, further improvements are needed. To date, treatment techniques remain a compromise between STATEMENT REGARDING FEDERALLY cost, processability and final product properties. Despite the SPONSORED RESEARCH ORDEVELOPMENT 10 significant research done in this area, there remains a need for economical Surface treatment of particulate titanium dioxide Not applicable. that provides improved handling, dispersion and final product BACKGROUND properties. 15 1. Field of Invention SUMMARY OF THE INVENTION The invention relates generally to a coated particulate Solid compositions and, more particularly, but not by way of limi The present invention provides a coated particulate solid tation, to a particulate inorganic Solid having deposited on its composition for use primarily in polymeric matrices, as well Surface a treatment oil containing lipids, a process for Surface as a process for Surface treating a particulate inorganic Solid treating a particulate inorganic Solid to produce a lipid-coated and for loading particulate titanium dioxide into polymer particulate inorganic Solid, and a process for loading Such a concentrate. The coated particulate Solid composition of the Solid in polymer compositions. present invention includes a particulate inorganic Solid hav 2. Background of the Invention ing deposited on its Surface a treatment oil containing lipids. Particulate inorganic pigments are used as opacifiers and 25 Optionally, the particulate inorganic Solid includes a base colorants in many industries, including the coatings, plastics, particulate of titanium dioxide, Zinc sulfide, Zinc oxide, iron and paper industries. In particular, titanium dioxide pigments, oxide, lead oxide, aluminum oxide, silicon dioxide, Zirco generally in the form of finely divided powders, are added to nium oxide and chromium oxide, kaolin, talc, mica or cal a polymer melt for imparting whiteness and/or opacity to the cium carbonate. The treatment oil can comprise a vegetable finished plastic article. 30 oil containing the lipids, or can include glycerides Such as In general, the effectiveness of the particulate pigment in triglycerides and diglycerides. Optionally, the treatment oil such applications depends on how evenly the pigment can be includes phospholipids. dispersed in the polymer melt. For this reason, pigments are A process for Surface treating a particulate inorganic solid generally handled in the form of a finely divided powder. to produce a lipid-coated particulate Solid includes providing Titanium dioxide, the most widely used white pigment in 35 commerce today due to its ability to confer high opacity when a particulate inorganic Solid and mixing the particulate inor formulated into end-use products, is handled in the form of a ganic Solid with a treatment oil containing lipids to form a finely divided powder in order to maximize the opacifying lipid-coated particulate Solid. The particulate inorganic Solid properties imparted to materials formulated therewith. How can include a titanium dioxide base in which case the process ever, titanium dioxide powders are inherently dusty and fre 40 optionally includes a drying step. When Such particulate inor quently exhibit poor powder flow characteristics during the ganic Solids having a titanium dioxide base have also under handling of the powder itself, especially during formulation, gone filtration and washing steps, the step of mixing the compounding, and manufacture of end-use products. In addi particulate inorganic Solid with the treatment oil comprising tion, these particles typically have a hydrophilic Surface, lipids can be performed after the filtration and washing steps, making them difficult to incorporate in hydrophobic materi 45 but prior to a drying step. Optionally, the lipid-coated particu als such as plastics, and thus, they require long periods of time late solid comprising titanium dioxide is micronized and the and/or high levels of energy to achieve optimum dispersal. treatment oil comprising lipids is mixed with the particulate To this end, chemical modification of titanium dioxide inorganic solids before or during the micronizing step. In particle Surfaces has been a preferred approach to achieving another embodiment, the treatment oil comprising lipids is optimum pigment opacity as well as good flow characteris 50 mixed with the particulate inorganic Solids after the micron tics. Surface treatment agents are typically added to the par izing step. ticulate titanium dioxide; however, the selection of the Sur A process for loading particulate titanium dioxide into a face treatment agent is often a compromise between polymer concentrate includes the following steps. A treat effectiveness, cost, compatibility with other additives in the ment oil comprising lipids is mixed with a particulate tita plastic, and performance properties in the plastic. 55 A variety of treatments has been studied. For example, U.S. nium dioxide to form a lipid-coated particulate titanium diox Pat. No. 7,601,780 discloses a silanized inorganic powder ide. The lipid-coated particulate titanium dioxide is then treated with a long chain fatty acid and U.S. Patent Applica mixed with a polymer resin to form a polymer concentrate tion Publication No. U.S. 2003/0029359 A1 discloses pig comprising lipid-coated particulate titanium dioxide present ment particles treated with polysaturated and unsaturated 60 in an amount in the range of from about 50% to about 85% by fatty acid esters. U.S. Pat. No. 6,646,037 discloses treating weight of the polymer concentrate. titanium dioxide with alkyl sulfonic acid salts, and U.S. Pat. Thus, utilizing (1) the technology known in the art; (2) the No. 6,765,041 discloses treatment with alkyl phosphate above-referenced general description of the presently esters. Organosilicon compounds have also been used. For claimed and/or disclosed inventive process(es), methodology instance, U.S. Pat. No. 4,061,503 discloses the treatment of 65 (ies), apparatus(es) and composition(s); and (3) the detailed particulate titanium dioxide with a siloxane compound for description of the invention that follows, the advantages and improving the dispersibility of titanium dioxide in pigmented novelties of the presently claimed and/or disclosed inventive US 8,436,077 B2 3 4 process(es), methodology(ies), apparatus(es) and composi weight of the particulate inorganic Solid prior to depositing tion(s) would be readily apparent to one of ordinary skill in the treatment oil comprising lipids. In some applications an the art. ultrafine particle size is used having an average primary par ticle size in the range of from about 0.001 micron to 0.1 DETAILED DESCRIPTION OF THE INVENTION micron, and due to the higher Surface area, the lipid-contain ing treatment oil is often present on the Surface in an amount Before explaining at least one embodiment of the invention in the range of from about 10% to about 25% by weight of the in detail, it is to be understood that the invention is not limited particulate ultrafine inorganic solid, based on the weight of in its application to the details of construction, experiments, the particulate ultrafine inorganic Solid prior to depositing the exemplary data, and/or the arrangement of the components 10 treatment oil comprising lipids. set forth in the following description. The invention is capable In one embodiment, the particulate inorganic Solid com of other embodiments or of being practiced or carried out in prises a titanium dioxide base. Any form of titanium dioxide various ways. Also, it is to be understood that the terminology is suitable for the particle of the invention. Preferably, the employed herein is for the purpose of description and should titanium dioxide is in the rutile oranatase form. The titanium not be regarded as limiting. 15 dioxide can be prepared by any known process. Such as the There is a need for new particulate pigment coating tech Sulfate process or the chloride process. nologies having the capability of providing increased bulk The titanium dioxide useful in the invention covers abroad density and improved dispersibility and lacing resistance in average particle size ranging from about 0.001 micron to plastic, but in a cost-effective manner. As mentioned above, a about 20 micron (um). As described above, for use in typical variety of methods have been studied for preparing such pigmentary applications, the titanium dioxide typically has a pigments, but typically present a compromise between effec particle size in the range of from about 0.15um to about 0.35 tiveness, cost, compatibility with other additives in the plas um (hereinafter referred to as "pigmentary particle size tic, and performance properties in the plastic. Surprisingly, it range'). Often, pigmentary titanium dioxide has a particle has been discovered that coating particulate inorganic Solids size in the range of from about 0.2 Lum to about 0.35um. In with lipids, Such as Vegetable oil, can provide increased bulk 25 Some applications, an ultrafine particle size is used having an density, improved dispersibility in plastic materials, and average primary particle size (crystallite size) in the range of excellent performance properties such as lacing resistance in from about 0.001 um to 0.15 um (hereinafter referred to as the plastic materials. “ultrafine particle size range'). The ultrafine titanium dioxide Examples of suitable base particulate for forming the is often a precipitated material comprised of Small anatase coated particulate solid composition, and which are com 30 primary crystallites, typically on the order of a few nanom monly used in plastic materials include, but are not limited to, eters (nm) in size. These crystallites are further bonded titanium dioxide, Zinc sulfide, Zinc oxide, iron oxide, lead together to form what are often referred to as primary aggre oxide, aluminum oxide, silicon dioxide, Zirconium oxide, gates which typically range in diameter from 0.05 micron (50 chromium oxide, kaolin, talc, mica and calcium carbonate. nm) to 0.1 micron (100 nm). These primary aggregates can The lipid-containing treatment oil can be present on the 35 also be further bonded together to form agglomerates that are particulate inorganic Solid over a wide range and depends in roughly one or two microns (1-2 um) in diameter, as mea large part on the particle size. The particle size can range from sured by the D50 (median size). The final agglomerated par about 0.001 micronto about 20 microns. When the particulate ticle can thus have an internal porous network. inorganic Solid is considered a filler or an extender, Such as Note that in the case of ultrafine particles, the term “pri kaolin, calcium carbonate, talc and mica, the particle size 40 mary particle size” refers to the crystallite size rather than the range is normally from about 0.5 micron to about 20 microns. aggregate or agglomerate particle size. To avoid confusion, For particulate inorganic Solids used specifically for pigmen when referring to crystallite size hereinafter and in the tary purposes, the average particle size ranges from about 0.1 appending claims, the term "crystallite size' parenthetically microns to about 0.5 microns. Generally, when the particulate follows the term “average primary particle size.” inorganic Solid is titanium dioxide in the pigmentary form, 45 The titanium dioxide may be untreated titanium dioxide the average particle size is in the range of 0.15 microns to 0.35 obtained directly from a production process Such as the chlo microns. When the particulate inorganic Solid is transparent ride or sulfate processes. Alternatively, the titanium dioxide titanium dioxide, the average particle size is typically from may be treated with at least one coating material prior or about 0.01 to 0.15 microns, while ultrafine or nanoparticle Subsequent to treatment with the lipid-containing treatment Solids can have an average primary particle size in the range 50 oil of the present invention. Suitable coating materials include of from about 0.001 micron to about 0.1 micron. When the inorganic oxides, such as aluminum oxide, silicon dioxide, particulate inorganic Solid shape is roughly spherical, these Zirconium oxide, inorganic phosphates, acid-soluble titanium measurements represent the diameter. When the particulate dioxide, mixtures thereof and the like. For example, rutile inorganic Solid shape is acicular or nonspherical, then these titanium dioxide (TiO) is coated with alumina (AlO4). The measurements represent the measurement of the longest 55 amount of alumina is preferably 0.01% to 1.0% by weight in dimension. terms of Al-O relative to TiO. Processes to deposit metal Overall, the lipid-containing treatment oil is present on the oxides onto a titanium dioxide are well knownto those skilled particulate inorganic solid in an amount in the range of from in the art. Preferably, the metal oxides are added by wet about 0.1% to about 25% by weight of the particulate inor treatment or by gas-phase deposition. Suitable organic coat ganic Solid, based on the weight of the particulate inorganic 60 ing materials include, but are not limited to, siloxanes, orga Solid prior to depositing the treatment oil comprising lipids. nohalosilanes, organophosphinic compounds, organosul However, when used in filler and pigmentary applications, fonic compounds, polyalcohols such as trimethylolpropane wherein the particulate inorganic Solid has a particle size in and alkanolamines, such as triethanolamine. the range of from about 0.1 micron to about 20 micron, the The treatment oil of the present invention comprises lipids. lipid-containing treatment oil is typically present on the Sur 65 Lipids are a group of naturally-occurring molecules which face in an amount in the range of from about 0.1% to about 5% includes fats, waxes, sterols, fat-soluble vitamins (such as by weight of the particulate inorganic Solid, based on the Vitamins A, D, E and K), monoglycerides, diglycerides, trig US 8,436,077 B2 5 6 lycerides, phospholipids, and others. Glycerides, also of the particulate inorganic Solid, based on the weight of the referred to as acylglycerols, are esters formed from glycerol particulate inorganic Solid prior to depositing the treatment and fatty acids. Glycerol has three hydroxyl functional oil. groups, which can be esterified with one, two, or three fatty Vegetable oils provide an excellent source of lipids for the acids to form monoglycerides, diglycerides, and triglycer treatment oil of the present invention. Suitable vegetable oils ides. Vegetable oils and fats, for example, contain mostly include edible oils, oils used for biofuel, drying oils, and other triglycerides, i.e. three moles of a fatty acid esterifying one oils containing lipids and derived from plants. Examples of mole of glycerine. The term “glyceride treatment oil as used major edible vegetable oils suitable for the present invention herein and in the appended claims, refers to a treatment oil include, but are not limited to, castor oil, coconut oil, corn oil, containing one or more monoglyceride, diglyceride, triglyc 10 cottonseed oil, hemp oil, mustard oil, olive oil, palm oil, eride, or combinations thereof. peanut oil, rapeseed oil (canola), rice bran oil, safflower oil, The glyceride treatment oils can be present on the Surface sesame oil, soybean oil, and sunflower seed oil. Other suitable of the particulate inorganic solid in an amount in the range of edible oils include nut oils such as almond oil, cashew oil, from about 0.1% to about 25% by weight of the particulate 15 hazelnut oil, macadamianut oil, pecan oil, peanut oil, pine oil, inorganic Solid, based on the weight of the particulate inor and the like. Oils from melon and gourd seeds can also be ganic Solid prior to depositing the treatment oil. For particu used. The amount of vegetable oil deposited on the surface of late inorganic Solids comprising titanium dioxide particles in the particulate inorganic Solid is preferably as described the pigmentary particle size range, the glyceride treatment oil above for glyceride treatment oils and treatment oils compris is typically present on the Surface in an amount in the range of ing phospholipids. from about 0.1% to about 5% by weight of the particulate Oils and fats are often distinguished based on their melting inorganic Solid, based on the weight of the particulate inor point; oils are liquid at room temperature, and fats are solid. ganic Solid prior to depositing the glyceride treatment oil. For However, the term "vegetable oil.” as used herein and in the particulate inorganic Solids comprising titanium dioxide par appended claims, refers to any lipid-containing oil or fat ticles in the ultrafine particle size range, the glyceride treat 25 obtained from plants, regardless of whether the material is ment oil is typically present on the Surface in an amount in the solid or liquid at room temperature. Solid fats can readily be range of from about 5% to about 25% by weight of the converted to liquid form, if desired, by heating or by, for particulate inorganic solid, based on the weight of the par example, dissolving in an appropriate solvent, therefore the ticulate inorganic Solid prior to depositing the glyceride treat distinction between oil and fat is not necessary. ment oil. 30 The methods for adding the lipid-containing treatment oil may be similar to methods for adding other Surface treatments To some extent, the characteristics of a particular glyceride that are flexibly and easily incorporated into production pro treatment oil can depend on the actual fatty acids present in cesses such as titanium dioxide production processes. Thus, the individual triglyceride molecules. Linear chain fatty acids there are many places during production of particulate inor are said to be saturated, and their presence in high proportions 35 ganic Solids in which the lipid-containing treatment oil may in a triglyceride mixture is likely to make it solid. A fatty acid be added and the points of additions described herein are not containing one double bond is said to be monounsaturated, meant to be exhaustive. The optimal point during which to the most common example being oleic acid which, like add the lipid-containing treatment oil will, in part, depend on stearic acid, has 18 carbon atoms. Fatty acids with two or the process in which it is to be incorporated. three double bonds are said to be polyunsaturated fatty acids 40 In the case of titanium dioxide particulate, and in the sim and their presence typically lowers the melting point. Thus, a plest of methods, the lipid-containing treatment oil may be triglyceride mixture containing a high proportion of monoun added by spraying or pouring into a system in which the saturated or polyunsaturated fatty acids is likely to be liquid. titanium dioxide is already present. To maximize the unifor The treatment oil of the present invention can also com mity of the distribution of the lipid-containing treatment oil, prise phospholipids. Phospholipids are a class of lipids typi 45 preferably, a mixing device is used to mix or to stir the cally containing a diglyceride, a phosphate group, and a lipid-containing treatment oil and the titanium dioxide. simple organic molecule. Phospholipids have a hydrophilic Devices such as a V-shell blender equipped with an intensifier "head containing the negatively charged phosphate or other bar for application of a liquid to a powder or other suitable group, and a hydrophobic “tail usually consisting of long mixing devices now known, or that come to be known to those fatty acid hydrocarbon chains. Their physical structure allows 50 skilled in the art may be used. phospholipids to be compatible with both hydrophilic and One preferred mixing device is a micronizer. The lipid hydrophobic surfaces and materials. containing treatment oil may be metered into a micronizer or When the treating oil comprises phospholipids, the phos jet pulverizer along with the titanium dioxide powder to be pholipid can be present on the Surface of the particulate inor ground. Air or steam micronization techniques may be used at ganic Solid in an amount in the range of from about 0.1% to 55 temperatures from room temperature up to 250° C. or higher. about 25% by weight of the particulate inorganic solid, based In a conventional production process, the lipid-containing on the weight of the particulate inorganic Solid prior to depos treatment oil may, by way of further example, be added to a iting the treatment oil. For particulate inorganic Solids com spray dryer feed or repulped filter cake, to a high intensity prising titanium dioxide particles in the pigmentary particle milling device, to a micronizer feed prior to, or concurrent size range, the phospholipids are typically present on the 60 with micronization, or to the dry micronized product. If a sand surface in an amount in the range of from about 0.1% to about mill is utilized to correct particle size, the lipid-containing oil 5% by weight of the particulate inorganic solid, based on the can be added to, for example, the sand mill discharge. Upon weight of the particulate inorganic Solid prior to depositing drying, the lipid-containing oil forms a coating on the particle the treatment oil. For particulate inorganic Solids comprising surfaces. In some embodiments, it is desirable to add the titanium dioxide particles in the ultrafine particle size range, 65 lipid-containing treatment oil after any filtration and washing the phospholipids are typically present on the Surface in an stages, but prior to any drying stage. In Such cases, it may be amount in the range of from about 5% to about 25% by weight desirable to add the lipid-containing treatment oil to a fluid US 8,436,077 B2 7 8 ized, washed filter cake with agitation in order to assure that the treated pigments of this invention impart greater uniform mixing of the lipid-containing treatment oil among lacing resistance to polymers into which they are incorpo the titanium dioxide particles. rated. If the lipid-containing treatment oil is added to a dry tita In order to further illustrate the present invention, the fol nium dioxide such as a spray dryer product or micronizer feed lowing examples are given. However, it is to be understood or product, particular care should be taken to ensure uniform that the examples are for illustrative purposes only and are not mixing of the lipid-containing treatment oil with the titanium to be construed as limiting the scope of the invention. dioxide powder. This may, for example, be accomplished by using a V-shell blender equipped with an intensifier bar or by Example 1 using other Suitable mixing devices. If the lipid-containing 10 treatment oil is combined with spray dryer product or micron 10 kg of neutral base oxidizer discharge slurry (42.5% izer feed, the treated titanium dioxide may be fluid energy solids) was heated at 60° C. with mixing while adding 54.7 milled using steam or air to produce a treated, finished tita gm of sodium aluminate solution (23.3% Al-O.). The pH of nium dioxide. Alternatively, the lipid-containing treatment the resulting 0.3% alumina base was raised to 8.4 with 50% oil may be added directly to the micronized finished titanium 15 dioxide. In some instances, it is desirable to add the lipid NaOH and the mixture was continued to mix for an additional containing treatment oil in stages, for example, to two or three 15 minutes while the temperature was attained at 60°C. The process points. slurry was then filtered and washed with 4250gm hot water. The composition and amounts of the lipid-containing treat The resulting cake was re-pulped and used for Surface treat ment oil are as described for the coated particulate solid ment. compositions. Once the lipid-coated pigment is formed, it The above prepared cake, equivalent to 1200 gm dry pig may then be combined with a polymer. The nature of the ment, was re-pulped in waterforming a 35-40% solids slurry; surface treatment of the present invention allows the treated 0.7% (8.4 gm) of MAZOLATM corn oil was added, and the pigments to be easily incorporated into a polymer matrix. The mixture was stirred for 5 minutes at room temperature. The phrase “polymer matrix” refers to the Substance comprising 25 corn oil was purchased from a retail food supplier. The slurry the polymer and the lipid-coated pigment. Polymers that may was then dried at 60° C. overnight, sieved through #8 mesh be of use in the present invention include polymers of unsub screen, and then micronized. stituted ethylene monomers, including polyethylene, polypropylene, polybutylene, and copolymers of ethylene Example 2 with alpha-olefins containing 4 to 12 carbon atoms or vinyl 30 acetate; Vinyl homopolymers, acrylic homopolymers and Example 2 was prepared as in Example 1, but the cake was copolymers, polyamides, polycarbonates, polystyrene, acry treated with 8.4 gm of Lou AnatM canola oil. The canola oil lonitrile-butadiene-styrenes and polyethers. Other suitable was purchased from a retail food Supplier. polymer types include, but are not limited to, polyvinylchlo Example 3 ride, polyurethanes, polysulfones, polyimides, polyesters and 35 chlorinated polyesters, polyoxyethylenes, phenolics, alkyds, Example 3 was prepared as in Example 1, but the cake was amino resins, epoxy resins, phenoxy resins and acetal resins. treated with 8.4 gm of GIANTTM olive oil. The olive oil was The lipid-coated pigment may be combined with the poly purchased from a retail food Supplier. mer and have a loading of up to about 87% by weight, based on the weight of the polymer matrix. Depending upon the 40 Example 4 application, the composition of lipid-coated titanium dioxide and polymer can contain other additives, fillers, and pig Example 4 was prepared as in Example 1, but the cake was ments. Zinc sulfide, barium sulfate, calcium carbonate, Zinc treated with 8.4 gm of WESSONTM soybean oil. The soybean Stearate, and combinations thereofare preferred pigments for oil was purchased from a retail food Supplier. use in the composition. The amount of lipid-coated titanium 45 dioxide used will vary dependent upon the final application. Example 5 One convenient technique is to first prepare a concentrate oflipid-coated titanium dioxide with the organic polymerand Example 5 was prepared as in Example 1, but the cake was then mix the concentrate with more organic polymers to treated with 8.4 gm of HOLLYWOODTM safflower oil. The achieve the desired weight ratio. A polymer concentrate typi 50 safflower oil was purchased from a retail food supplier. cally has a loading of lipid-coated pigment of about 50% to about 87% by weight based on the weight of the polymer Comparative Example matrix and often as high as 75% to about 87% by weight based on the weight of the polymer matrix. This loading may The Comparative Example was prepared as in Example 1, be used as a masterbatch. A "masterbatch' is meant to refer to 55 but the cake was treated with 0.60% by weight triethanola a mixture of two or more substances that are blended together mine based on the weight of dry pigment. and then blended with one or more other ingredients that may be the same as, or different from, either of the first two Lacing Evaluations substances. The methods for creating a masterbatch with the lipid-coated pigment are known to those skilled in the art. For 60 The high temperature stability of polymers containing pig example, lipid-coated titanium dioxide pigment can be dry ments is an important property of commercial polymer films, blended with the organic polymer and then mixed in the melt. especially polyethylene film applications. Voiding or “lac This can be done, for example, by using a Banbury mixer or ing” accompanies the failure of films and may manifest as a a twin screw extruder. void or hole in the plastic film. Lacing is believed to be a It has been found, Surprisingly and unexpectedly, that the 65 measure of volatility at specific weight percent pigment load treated pigments of this invention have increased bulk density ings and processing temperatures. Table 1 below, shows the 96 and enhanced dispersibility in plastic. It was further found moisture determined by a Mitsubishi CA-200 MoistureMe US 8,436,077 B2 10 terTM at 300° C. All pigment samples were conditioned for 24 Bulk Density hours at 23° C. with 50% humidity prior to testing. The sample loading was 0.25-0.3 gm. Nitrogen gas was used for Bulk density tests were conducted using the Tapped Den Sweeping. sity TesterTM model #JV2000 by Copley Scientific. The 250 The moisture contents for pigment coated with the above ml cylinder was filled with pigment until the 250 mark with identified triglyceride-containing vegetable oils are shown in out any tapping. The highest height and the weight were Table 1. A moisture content below 0.35% is considered recorded. The loose bulk density was determined as (weight acceptable, and below 0.28% is excellent. in gm/highest height in cm). The machine is then set to tap Lacing tests were conducted on 50% TiO, concentrate for 5 minutes and the highest height was re-recorded. The samples prepared using a Haake Record 9000 Computer Con 10 packed bulk density is calculated as (weight in gm/highest trolled Torque Rheometer. Thus, 125 g of TiO, and 125 g of height after tapping in cm). low density polyethylene LDPE 722TM manufactured by Dow Results of the bulk density tests are shown in Table 2. A Chemical Company were dry-blended and added to the 75° C. packed bulk density of 0.6-0.8 is considered acceptable, preheated chamber with rotors running at 50 rpm. One minute 15 while that above 0.8 is considered excellent. after addition of the TiO/LDPE mixture, the chamber tem perature was raised to 105° C. Frictional heat generated by the TABLE 2 mixing process was allowed to drive the rate of incorporation of the TiO into the LDPE until a steady state mixture was Bulk Density Test Results achieved. The concentrate was removed from the mixing Loose Bulk Packed Bulk chamber and placed into a Cumberland Crusher to obtain Density Density finely granulated 50% concentrate samples. The granulated Sample Description grams cm g/cm cm g/cm concentrates were conditioned for 48 hours at 23°C. and 50% Example 1 0.7% corn oil 189 248 0.762 204 0.926 relative humidity. These concentrates were then let down into Example 2 0.7% canola oil 177 2SO 0.708 194 O.912 Dow Chemical 722TM LDPE to achieve a 20% loading of 25 Example 3 0.7% olive oil 183 2S4 O.720 2OO O.915 TiO, in the final film. Example 4 0.7% soybean oil 2O5.4 2S4 O.809 2O2 1017 Lacing evaluations were run on a 1-ft extruder equipped Example 5 0.7% Safflower 173.3 2SO O.6939 196 0.884 with a cast film slot die. A temperature profile of 625° F. die, 515° F. clamp ring, 415° F. Zone 3,350° F. Zone 2, and 300° F. Zone 1 was used. The screw speed was set at about 90 rpm. 30 Dispersion Testing A 25.4 cm polished chrome chill roll, set in conjunction with the extruder, was used to maintain a 75-um-film thickness, Using a small-scale laboratory extrusion apparatus, a mea and to cool and transport the films. The chill roll distance from Sure of pigment dispersion into organic polymers is obtained the die lips was about 22 mm and the temperature was about 35 by measuring the relative amount of pigment trapped onto 27O C. screens of extruder Screen packs. Tests are run using a 75% After the TiO/LDPE mix was placed in the hopper, the TiO concentrate matrix with low density polyethylene, the material was allowed to purge until the appearance of a white matrix prepared using a HaakeTM 3000 Rheomix mixer. The tint in the film was first noted. To ensure the concentration of mixer is controlled and monitored with a HaakeTM 9000 TiO in the film had stabilized, a time interval of two minutes 40 Rheocord Torque Rheometer. 337.7 grams of micronized was allowed before lacing observations were recorded and a TiO, and 112.6 grams of NA209 LDPE manufactured by film sample obtained. The extruder was then purged with Equistar were dry blended and added to the 75° C. mixing LDPE until the film turned clear. Lacing performance was chamber with rotors operating at 50 rpm. The mixer tempera determined by counting the relative size and number of holes ture was programmed to increase to 120° C. one minute after generated in a film sample laid out on a dark Surface. The 45 the dry blend was introduced to the mixing chamber. After a lacing evaluation results for pigment coated with the above steady state mixture was achieved, the compound was mixed identified vegetable oils are shown in Table 1. A 1.0-3.0 rating for an additional 3 minutes. The compound was removed system was used. A rating of 1 was given to films with no from the chamber and granulated using a Cumberland lacing, 2 was given to films showing the onset of lacing, and crusher. 3 was given to films with extreme lacing. Increments of 0.1 50 Dispersion tests are conducted using a Killion single screw were used to give an indication of the relative performance extruder, model KL 100 equipped with a 20:1 length to diam between samples. eter screw. The extruder is preheated at 330° F (166° C.), 350° F (177° C), 390° F (199° C), and 380° F (193° C.) TABLE 1. from Zone 1 to the die, respectively, and operated at 70 rpm. A 55 purge of 1000 grams of NA952 LDPE manufactured by Equi Lacing Test Results star is run through the system, and a new screen pack is 300° C. installed. The screen pack consists of 40/500/200/100 mesh Sample # ID %. Moisture Lacing screens from the die towards the extruder throat. After tem perature stabilization, 133.33 grams of granulated 75% TiO, Example 1 0.7% corn oil O.2494 not measured Example 2 0.7% canola oil O.2S32 1.O 60 concentrate sample matrix is fed into the extruder. This is Example 2 0.8% canola oil 1.O followed with 1500grams of NA952 purge as the feed hopper Example 3 0.7% olive oil O.2519 not measured empties. After the LDPE purge is extruded, the screens are Example 4 0.7% soybean oil O.22SO not measured Example 5 0.7% Safflower oil O.2322 not measured removed, separated and tested using a relative count tech Comparative 0.6% triethanolamine 1.4 nique from the measurements from an X-ray fluorescence Example 65 spectrometer. The number of TiO2 counts per second is obtained for the 100, 200 and 500 mesh screens in the pack and totaled to obtain the dispersion result. US 8,436,077 B2 11 12 The dispersion test results are shown in Table 3. Lower the step of mixing the lipid-containing treatment oil with the TiO2 counts per second are desired. A count result of less than particulate titanium dioxide to form the lipid-coated particu 5,000 is considered to represent good dispersion, and less late titanium dioxide. than 2,000 is considered to be excellent dispersion. 8. The process of claim 7, further comprising the step of drying the lipid-coated particulate titanium dioxide. TABLE 3 9. The process of claim 1, further comprising the step of: micronizing the particulate titanium dioxide. Dispersion Test Results (TiO, Counts/Second) 10. The process of claim 9, wherein the step of mixing the Sample Description 100 2OO 500 Total lipid-containing treatment oil with the particulate titanium 10 Example 1 0.7% corn oil 348 163. 281 792 dioxide to form the lipid-coated particulate titanium dioxide Example 2 0.7% canola oil 305 133 242 68O occurs during the step of micronizing the particulate titanium Example 3 0.7% olive oil 174 128 204 506 dioxide. Example 4 0.7% vegetable oil 761 196 172 1,129 Example 5 0.7% safflower 534 201 216 951 11. The process of claim 9, wherein the step of mixing the Comparative 0.6% triethanolamine - - - 13,700 15 lipid-containing treatment oil with the particulate titanium Example dioxide occurs prior to the step of micronizing the particulate titanium dioxide. From the above examples and descriptions, it is clear that 12. The process of claim 9, wherein the step of mixing the the present inventive process(es), methodology(ies), appara lipid-containing treatment oil with the particulate titanium tus(es) and composition(s) are well adapted to carry out the dioxide occurs after the step of micronizing the particulate objects and to attain the advantages mentioned herein, as well titanium dioxide, and prior to the step of mixing the lipid as those inherent in the presently provided disclosure. While coated particulate titanium dioxide with a polymer resin to presently preferred embodiments of the invention have been form a polymer concentrate. described for purposes of this disclosure, it will be understood 13. The process of claim 1, wherein the lipid-containing that numerous changes may be made which will readily sug 25 treatment oil is combined with the particulate titanium diox gest themselves to those skilled in the art and which are ide pigment in an amount of from about 0.1% to about 5% by accomplished within the spirit of the presently claimed and weight of the particulate titanium dioxide pigment, based on disclosed inventive process(es), methodology(ies), apparatus the weight of the particulate titanium dioxide pigment prior to (es) and composition(s) described herein. depositing the lipid-containing treatment oil. What is claimed is: 30 14. The process of claim 1, wherein the lipid-containing 1. A process for loading particulate titanium dioxide into a treatment oil is combined with the particulate titanium diox ide in an amount of from about 5% to about 25% by weight of polymer concentrate, the process comprising the steps of: the particulate titanium dioxide pigment, based on the weight (a) mixing a lipid-containing treatment oil with a particu of the particulate titanium dioxide pigment prior to depositing late titanium dioxide to form a lipid-coated particulate the lipid-containing treatment oil. titanium dioxide, wherein the lipid-containing treatment 35 15. A polymer concentrate comprising particulate titanium oil comprises at least one of a vegetable oil, a triglycer dioxide particles coated with a lipid-containing treatment oil ide, and a diglyceride; and and dispersed in a polyolefin polymer matrix, the lipid coated (b) mixing the lipid-coated particulate titanium dioxide particulate titanium dioxide present in the polymer concen with a polymer resin to form a polymer concentrate, trate in an amount of about 50% to about 87% based on the wherein the polymer resin comprises a polyolefin, and 40 wherein the particulate titanium dioxide present in the weight of the polymer matrix, wherein the lipid-containing polymer concentrate is in an amount of from about 50% treatment oil comprises at least one of a vegetable oil, a to about 85% by weight of the polymer concentrate. triglyceride, and a diglyceride. 2. The process of claim 1, wherein the treatment oil com 16. The polymer concentrate of claim 15, wherein the prises a vegetable oil. 45 particulate titanium dioxide particles are coated with a veg 3. The process of claim 1, wherein the treatment oil com etable oil. prises at least one triglyceride. 17. The polymer concentrate of claim 15, wherein the 4. The process of claim 1, wherein the treatment oil further particulate titanium dioxide particles are at least partially comprises at least one phospholipid. coated with a triglyceride. 18. The polymer concentrate of claim 15, wherein the 5. The process of claim 1, wherein the polyolefinis selected 50 particulate titanium dioxide particles are at least partially from the group consisting of polyethylene, polypropylene, coated with a diglyceride. and polybutylene, and combinations thereof. 19. The polymer concentrate of claim 15, wherein the 6. The process of claim 1, wherein the polyolefin is poly lipid-containing treatment oil further comprises at least one ethylene. phospholipid. 7. The process of claim 1, further comprising the step of 55 filtering and washing the particulate titanium dioxide prior to UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. : 8.436,077 B2 Page 1 of 1 APPLICATIONNO. : 12/639583 DATED : May 7, 2013 INVENTOR(S) : Modasser El-Shoubary It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below:

In the Claims:

Column 12, line 38: After “matrix, the delete “lipid

Signed and Sealed this Twenty-third Day of July, 2013

Teresa Stanek Rea Acting Director of the United States Patent and Trademark Office