Millennium Inorganic Chemicals, Inc.

Scm Chemicals, Inc.

Millenium Inorganic Chemicals, Inc.

Cristal Usa, Inc.

Robert J Kostelnik

Modasser El-Shoubary

Charles A Wheddon

Fu-Chu Wen

Leon Weber

Christopher J Drury

Modasser El-Shoulbary

A particle of titanium dioxide treated with a polysiloxane is disclosed. One or more silicon atoms of the polysiloxane is substituted with an alkylene group terminating with a silyl group containing three substituents selected from the group consisting of hydroxy, halo, alkoxy, acetoxy, and mixtures thereof. These treated particles are blended with organic polymers to form a polyethylene polymer matrix having dispersed therein at least 55 wt % polysiloxane modified titanium dioxide particles.

Polysiloxane modified titanium dioxide

A particle of titanium dioxide treated with a polysiloxane is disclosed. One or more silicon atoms of the polysiloxane are substituted with an alkylene group that is terminated with a silyl group containing three substituents selected from the group consisting of hydroxy, halo, alkoxy, acetoxy, and mixtures thereof. These treated particles are blended with organic polymers.

A unique treatment for pigments is provided. This treatment, which uses certain organo-phosphoric acids and/or their salts, imparts improved physical and chemical qualities including lacing resistance, improved dispersion and decreased chemical reactivity when these treated pigments are incorporated into polymeric matrices.

Pigments treated with organo-phosphoric acids and their salts

A treatment for particulate inorganic solids is provided. This treatment, which uses certain organophosphinic compounds, imparts improved physical and chemical qualities including lacing resistance, improved dispersion and decreased chemical reactivity when these treated particulate inorganic solids are incorporated into polymeric matrices. The addition of the organophosphinic compounds of the present invention may flexibly be incorporated into known processes at varying points, and are preferably added downstream of any filtering steps or to a dry particulate inorganic solid.

Particulate inorganic solids treated with organophosphinic compounds

A unique treatment for pigments is provided. This treatment, which uses certain organo-acid phosphate molecules, imparts improved physical and chemical qualities including lacing resistance, improved dispersion and decreased chemical reactivity when these treated pigments are incorporated into polymeric matrices.

Organo-acid phosphate treated pigments

A treatment for pigments is provided. This treatment, which uses certain organosulfonic compounds, imparts improved physical and chemical qualities including lacing resistance, improved dispersion and decreased chemical reactivity when these treated pigments are incorporated into polymeric matrices. The addition of organosulfonic compounds may flexibly be incorporated into known processes at varying points, and are preferably added downstream of any filtering steps.

Pigments treated with organosulfonic compounds

The present invention provides a treatment method for rendering inorganic oxide particles, such as TiO pigment, hydrophobic by predispersing a suitably reactive organohalosilane into an aqueous media, using intensive mixing means (such as a rotor stator emulsifier or inline static mixer) to form a reactive dispersion. When this dispersion is combined with inorganic oxide particles, such as TiO pigment, under sufficient agitation, a hydrophobic inorganic oxide can be formed. The oxides formed by the present invention have good mechanical properties, such as dispersibility in nonpolar substances (i.e., plastics), and they do not degrade physical properties of the pigmented nonpolar substance, such as lacing resistance of thermoplastics.

Processes for preparing hydrophobic inorganic oxide pigments

The present invention discloses high solids slurries of anatase titanium dioxide pigment comprising greater than about 75% by weight of anatase TiO pigment dispersed in water. A process for producing the slurries of the present invention is disclosed which comprises the steps of a) dry milling the anatase titanium dioxide pigment, preferably by pressure rolling, and b) mixing the dry milled pigment with water in the presence of an acrylic acid dispersant.

Very high solids TiO2 slurries

The present invention provides a process for the production of hydrophobic inorganic oxide products which comprises reacting the inorganic oxide particles with organohalosilanes, preferably organochlorosilanes, to produce hydrophobic organosilane coated inorganic oxides. It is preferred that the organohalosilane compounds be reacted with the inorganic oxide particles in an aqueous slurry and subjected to intense mixing. The inorganic oxide pigments prepared by the processes of this invention have essentially quantitative retention of the organosilanes and contain no adsorbed aldehydes on their surface. The by-products produced in the preferred embodiments of the invention are innocuous salts, which are environmentally safe and readily disposable.

Silane treated inorganic pigments

The present invention discloses high solids slurries of anatase titanium dioxide pigment comprising greater than about 75% by weight of anatase TiO,pigment dispersed in water. A process for producing the slurries of the present invention is disclosed which comprises the steps of a) dry milling the anatase titanium dioxide pigment, preferably by pressure rolling, and b) mixing the dry milled pigment with water in the presence of an acrylic acid dispersant.

The present invention discloses high solids slurries of sulfate process, anatase titanium dioxide pigment. The improvements of these slurries over those of the prior art are improved slurry stability, tolerance to calcium and magnesium ions, foaming tendencies and reduced tendency to flocculate. The slurries of the present invention are comprised of at least 65% by weight of anatase TiO.sub.2 pigment produced by the sulfate production process dispersed in water containing a sufficient quantity of a dispersing agent selected from the group consisting of acrylic acid homopolymers and copolymers that are predominantly acrylic acid and contain at least one comonomer selected from the group consisting of maleic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, acrylamide, acrylonitrile, ethylene, propylene, styrene and esters of the above acids, which have been partially or completely neutralized with a neutralizing agent having a monovalent group and at least one neutralizing agent having a polyvalent group. A process for producing the slurries of the present invention is disclosed and comprises the steps of a) introducing the dispersing agent into water, b) adjusting the pH to a value greater than 7, c) adding the TiO.sub.2, with adequate mixing to break up large agglomerates, and, optionally, d)grinding in the presence of a suitable grinding medium to achieve the desired mean particle size for pigmentary applications.

High solids anatase TiO.sub.2 slurries

The present invention provides a process for the production of hydrophobic inorganic oxide products which comprises reacting the inorganic oxide particles with organohalosilanes, preferably organochlorosilanes, to produce hydrophobic organosilane coated inorganic oxides. It is preferred that the organohalosilane compounds be reacted with the inorganic oxide particles in an aqueous slurry. The inorganic oxide pigments prepared by the processes of this invention have essentially quantitative retention of the organosilanes and contain no adsorbed aldehydes on their surface. The by-products produced in the preferred embodiments of the invention are innocuous salts, which are environmentally safe and readily disposable.

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Ellicott City, MD, United States of America

Robert J Kostelnik