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KR-102963528-B1 - Method for manufacturing a metal oxide pigment composite with controlled cohesion and the product thereof

KR102963528B1KR 102963528 B1KR102963528 B1KR 102963528B1KR-102963528-B1

Abstract

A method for preparing a composite containing submicron-sized metal oxide pigment particles and a natural organic compound is disclosed, the method comprising the step of grinding the metal oxide pigment and the oligomeric and/or polymeric carbohydrate together using a ball mill to obtain a pigment composite containing particles having a submicron particle size range and having an outer surface partially or completely covered by oligomeric and/or polymeric carbohydrates; additionally, a pigment composite thus obtained comprising pigment particles having an average hydrodynamic diameter of less than 1 μm is disclosed.

Inventors

  • 크라보또, 쟌카를로
  • 랏스로, 이친스키
  • 포글리아, 엘레나

Assignees

  • 프로도띠 지안니 에스.알.엘.

Dates

Publication Date
20260511
Application Date
20200923
Priority Date
20190927

Claims (20)

  1. A method for manufacturing a composite material containing submicron-sized metal oxide pigment particles and a natural organic compound, wherein the method comprises: a) a step of providing a metal oxide pigment and an oligomeric or polymeric carbohydrate; b) A step of grinding the metal oxide pigment and the oligomeric or polymeric carbohydrate in a ball mill to obtain a pigment composite comprising metal oxide particles having a submicron particle size range and having an outer surface partially or completely covered by the oligomeric or polymeric carbohydrate. Includes, The mass ratio of the metal oxide pigment provided in step a) and the oligomeric or polymeric carbohydrate is 1:10 to 10:1, and Before or during the grinding step b), a base additive is added and mixed into the metal oxide pigment, and The above base additive comprises an inorganic base additive selected from the group consisting of alkali hydroxide, alkali-earth hydroxide, carbonates, hydrogen-carbonates, and any combination thereof. method.
  2. In paragraph 1, The mass ratio of the metal oxide pigment to the oligomeric or polymeric carbohydrate is 1:5 to 5:1, method.
  3. In paragraph 1, The ball mill above is selected from the group consisting of planetary ball mills, roll ball mills, and cylindrical ball mills. method.
  4. In paragraph 1, The grinding step b) is performed at a ball-to-mass ratio of 2:1 to 15:1, method.
  5. In paragraph 1, The grinding step b) above is performed under dry milling conditions or wet milling conditions, method.
  6. In paragraph 1, The grinding step b) is performed at a rotational speed of 200 rpm to 700 rpm, method.
  7. In paragraph 1, The grinding step b) is performed for 0.5 to 15 hours, method.
  8. In paragraph 1, The metal oxide pigment is a transition metal oxide pigment selected from the group consisting of iron oxide (III), iron oxide (II, III), titanium oxide, chromium oxide (III), manganese oxide (IV), zinc oxide, cobalt oxide (II), zirconium oxide (IV), tungsten oxide (VI) and any combination thereof. method.
  9. In paragraph 1, The above oligomeric or polymeric carbohydrate is selected from the group consisting of ionic cellulose, nonionic cellulose, derivatives of ionic or nonionic cellulose, starch, alginates, hyaluronates, chitosanes, carrageenans, pectins, cyclodextrins, and any combination thereof. method.
  10. In Paragraph 9, The above oligomeric or polymeric carbohydrate is cyclodextrin, method.
  11. In Paragraph 9, The above oligomeric or polymeric carbohydrate is ionic cellulose, nonionic cellulose, or a cellulose derivative, method.
  12. delete
  13. delete
  14. In paragraph 1, The above-mentioned inorganic base additive is sodium hydroxide, sodium carbonate, or sodium bicarbonate, method.
  15. In Paragraph 14, The mass ratio of the pigment to the inorganic base additive is 1:2 to 10:1, method.
  16. delete
  17. In paragraph 1, The above base additive is a combination of the above inorganic base additive and organic base additive, method.
  18. A pigment composite that can be obtained by the method of claim 1, comprising a metal oxide pigment, an oligomeric or polymeric carbohydrate, and an inorganic base additive, The above-mentioned inorganic base additive is selected from the group consisting of alkali hydroxides, alkali-earth hydroxides, carbonates, bicarbonates, and any combination thereof, and The pigment composite comprises pigment particles having a submicron particle size range and whose outer surface is partially or completely covered by the oligomeric or polymeric carbohydrate. The above pigment particles have a mean hydrodynamic diameter of less than 1 μm, measured according to the procedure specified in ISO 22412:2017, Pigment composite.
  19. In Paragraph 18, Suspended in an aqueous medium having a pH of 6 to 12, Pigment composite.
  20. A cosmetic composition comprising the pigment composite according to claim 18 or 19.

Description

Method for manufacturing a metal oxide pigment composite with controlled cohesion and the product thereof In various industrial fields, especially in the cosmetics industry, pigments generally need to have a size between 0.3㎛ and 0.8㎛. Because commercially available pigments have particle sizes closer to the micrometer scale than the nanometer scale, it is difficult to uniformly cover the surface to which the pigment-coloring agent is applied by achieving a homogeneous dispersion. The particle size of commercially available pigments can be between 0.1㎛ and 10㎛. Various grinding technologies can be used to produce formulations that are homogeneous and can uniformly cover various types of surfaces throughout their shelf life. By reducing particle size to the submicron scale, not only is the stability of pigment-dispersed formulations increased, but the overall quality during application is also improved. For example, the occurrence of unwanted streaking is reduced. Size reduction using milling is well known: as an easy method for designing and manufacturing, it is applied not only to metal production but also to the post-processing of various solids. By changing the milling parameters, the particle size reduction during the milling process can be controlled. However, once pigment particles are dispersed in a specific suspension or formulation, they tend to merge upon contact to form larger particles, causing de-mixing of the suspension and formulation due to precipitation, creaming, aggregation, and/or coalescence. Specifically, the most commonly used metal oxide-based pigments allow for the formation of stable compositions in neutral to mild basic environments, but the resulting colloidal properties of microstructures and nanostructures exhibit significant instability as the pH of the dispersion medium increases. Schudel et al., J. Colloid Interface Sci. , 1997, 196, 241 disclose that the aggregation and destabilization of iron oxide nanoparticles are accelerated depending on the pH. Wetting and dispersion additives are used to improve physicochemical and colloidal properties. The use of artificial surfactants as wetting and dispersion additives is known in the art. Surfactants can interact in various ways, but generally, non-boding interactions are dominant between them. Among these interaction forces, electrostatic properties are traditionally considered the most important stabilizing factor. In aqueous dispersions, the central pigment particle is surrounded by an electrochemical double layer of oppositely charged ions or dipoles closely attached to the particle. The strengths of attractive and repulsive forces vary with distance, and in the case of a strongly expressed double layer, the repulsive factor is dominant. Therefore, surfactants can be successful in obtaining a stable dispersion containing pigment. However, if the aforementioned electrochemical double layer is damaged (e.g., by the addition of an electrolyte), attractive forces become dominant and dispersion breaks down. For example, this situation may occur during the manufacturing process of cosmetic formulations. Furthermore, another common problem associated with surfactants and other additives is that they can cause serious issues with the properties of the formulations to which they are added; rheological changes are highly likely to occur, for example, a decrease in viscosity is very common. In addition, the use of surfactants has a significant impact on a wide range of intrinsic properties of the formulation, such as color strength, hiding power, coagulation, gloss, flooding, and floating. Therefore, there is a particular need to provide new technologies for producing stable formulations containing pigments, especially in the fields of cosmetics and coatings. Such stable formulations containing pigments are expected to guarantee at least the following performance characteristics: i) minimal complexity of the production process, ii) excellent properties in terms of dispersibility, iii) excellent stability of the latter, and iv) strong coloring hues. Technology field The present invention relates to pigments and formulations for cosmetics and coatings containing them, and in particular to water-based pigment compositions in a submicron particle size range and dispersions thereof. outline The present invention relates to a method for manufacturing a pigment composite comprising pigment particles having a submicron size. Specifically, the main object of the present invention is a method for manufacturing a composite containing submicron-sized metal oxide pigment particles and a natural organic compound, wherein, in order to obtain a pigment composite containing particles having a submicron particle size range and having an outer surface covered with oligomeric and/or polymeric carbohydrates, the method comprises the step of grinding the metal oxide pigment and the oligomeric and/or polymeric carbohydrates together using a ball mill. Accordin