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EP-4404905-B1 - COMPOSITE OPACIFIER DISPERSION

EP4404905B1EP 4404905 B1EP4404905 B1EP 4404905B1EP-4404905-B1

Inventors

  • WANG, TAO
  • BAO, Xinyan
  • GUO, Yunlong
  • CHEN, HONGYU
  • PANG, XIAOYI

Dates

Publication Date
20260506
Application Date
20210924

Claims (10)

  1. A composite opacifier dispersion, comprising: a dispersion medium; a processing surfactant; and a plurality of composite opacifier particles, wherein the composite opacifier particles comprise metal oxide particles that are partially or completely encapsulated by a polycaprolactone polymer; wherein the metal oxide particles are selected from the group consisting of zinc oxide, titanium oxide and mixtures thereof; wherein the metal oxide particles have a z average particle size of > 100 nm as measured by dynamic light scattering; and wherein the composite opacifier particles have a z average particle size of > 150 nm to 2,500 nm as measured by dynamic light scattering.
  2. An aqueous personal care rinse off composition, comprising: a dermatologically acceptable aqueous vehicle; a dermatologically acceptable cleaning surfactant; and the composite opacifier dispersion according to claim 1.
  3. The aqueous personal care rinse off composition of claim 2, wherein the aqueous personal care rinse off composition is selected from the group consisting of a shampoo, a conditioning shampoo, a body wash formulation, an exfoliating body wash formulation, a facial wash formulation, an exfoliating facial wash formulation, a liquid hand soap formulation, a sulfate-free cleansing formulation and a mild cleansing formulation.
  4. The aqueous personal care rinse off composition of claim 3, wherein the dermatologically acceptable cleaning surfactant is selected from the group consisting of alkyl polyglucosides, glycinates, betaines, taurates, glutamates, sarcosinates, isethionates, sulfoacetates, alaninates, amphoacetates, sulfates, sulfonates, succinates, fatty alkanolamides and mixtures thereof.
  5. The aqueous personal care rinse off composition of claim 4, wherein the metal oxide particles are titanium dioxide particles.
  6. The aqueous personal care rinse off composition of claim 5, further comprising a rheology modifier.
  7. The aqueous personal care rinse off composition of claim 6, wherein the polycaprolactone polymer has a weight average molecular weight of 10,000 to 1,000,000 Daltons.
  8. The aqueous personal care rinse off composition of claim 6, wherein the polycaprolactone polymer has a weight average molecular weight of 20,000 to 200,000 Daltons.
  9. The aqueous personal care rinse off composition of claim 6, wherein the polycaprolactone polymer has a weight average molecular weight of 25,000 to 150,000 Daltons.
  10. A method of cleaning at least one of mammalian skin and hair, comprising: (a) applying an aqueous personal care rinse off composition according to claim 2 to the skin or hair of a mammal; and (b) rinsing the aqueous personal care rinse off composition from the skin or hair with a rinse water.

Description

The present invention relates to a composite opacifier dispersion, comprising: a dispersion medium; a processing surfactant; and a plurality of composite opacifier particles, wherein the composite opacifier particles comprise metal oxide particles that are partially or completely encapsulated by a polycaprolactone polymer; wherein the metal oxide particles are selected from the group consisting of zinc oxide, titanium oxide and mixtures thereof; wherein the metal oxide particles have a z average particle size of > 100 nm as measured by dynamic light scattering; and wherein the composite opacifier particles have a z average particle size of > 150 nm to 2,500 nm as measured by dynamic light scattering. In addition to cleaning performance, the aesthetic look and feel of a detergent is an important consideration for consumers. Thus, detergents typically contain a variety of ingredients that impact functionality, aesthetics, or both, including, for instance, surfactants, solvents, optional builder, and opacifiers. Opacifiers are materials that make a liquid system opaque. Thus, opacifiers are used to modify the appearance or aesthetics of detergents, for instance, by transforming the liquid from clear or translucent to opaque. Opacifiers can provide a uniform, luxurious, "lotionized" appearance to a liquid product. Opacifiers are usually formed of submicron sized particles that are delivered to a formulation as a suspension of the particles in a solvent (typically water). Since opacifiers are targeted to a formulation's aesthetics, it is generally desirable that their inclusion not interfere with the function of the formulation or otherwise negatively impact the formulation. For instance, opacifiers that exhibit limited compatibility with other materials in the formulation, have issues with stability, exhibit spotting or residue formation, are not favored. In addition, opacifiers that introduce large amounts of water into a formulation, e.g., by being effective only when used in large quantities, are also not favored, particularly for those formulations where limiting the quantity of water is desired, such as in concentrated detergents or unit dose packets. Accordingly, there remains a need for more sustainable opacifiers for use in aqueous personal care rinse off compositions; particularly wherein the sustainable opacifiers perform on par with conventional styrene acrylic copolymer based opacifiers. The present invention provides a composite opacifier dispersion, comprising: a dispersion medium; a processing surfactant; and a plurality of composite opacifier particles, wherein the composite opacifier particles comprise metal oxide particles that are partially or completely encapsulated by a polycaprolactone polymer; wherein the metal oxide particles are selected from the group consisting of zinc oxide, titanium oxide and mixtures thereof; wherein the metal oxide particles have a z average particle size of > 100 nm as measured by dynamic light scattering; and wherein the composite opacifier particles have a z average particle size of > 150 nm to 2,500 nm as measured by dynamic light scattering. The present invention provides an aqueous personal care rinse off composition, comprising: a dermatologically acceptable aqueous vehicle; a dermatologically acceptable cleaning surfactant; and a composite opacifier dispersion, comprising: a dispersion medium; a processing surfactant; and a plurality of composite opacifier particles, wherein the composite opacifier particles comprise metal oxide particles that are partially or completely encapsulated by a polycaprolactone polymer; wherein the metal oxide particles are selected from the group consisting of zinc oxide, titanium oxide and mixtures thereof; wherein the metal oxide particles have a z average particle size of > 100 nm as measured by dynamic light scattering; and wherein the composite opacifier particles have a z average particle size of > 150 nm to 2,500 nm as measured by dynamic light scattering. The present invention provides a method of cleaning at least one of mammalian skin and hair, comprising: (a) applying an aqueous personal care rinse off formulation according to the present invention to the skin or hair of a mammal; and (b) rinsing the aqueous personal care rinse off formulation from the skin or hair with a rinse water. DETAILED DESCRIPTION We have surprisingly found that a composite opacifier dispersion comprising metal oxide particles partially or completely encapsulated by a polycaprolactone polymer can be stably incorporated into aqueous personal care rinse off compositions to provide opacification on par with conventional styrene acrylate copolymer based opacifiers, while increasing the overall sustainability of the aqueous personal care rinse off composition. Unless otherwise indicated, ratios, percentages, parts, and the like are by weight. As used herein, unless otherwise indicated, the phrase "molecular weight" or MW refers to the weight avera