Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
2000-12-04
2003-03-18
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S376000, C510S443000, C510S452000
Reexamination Certificate
active
06534471
ABSTRACT:
This invention relates to a process for the production of colored detergent particles.
Heavy-duty detergents sometimes contain dyes in the form of specks. Colors commonly used are green and blue. The function of the dyes is, for example, to compensate for the yellowing of washed fabrics or to color the particles and hence to make the detergents more attractive to the consumer.
European patent application EP 0 138 410 describes a process for the production of colored washing powder in which a particulate dye is intensively mixed with a washing powder, for example in a feed screw, so that a colored washing powder is obtained. The dyes used are ultramarine blue, Duasyn Acid Blau and Polar Brillant Blau.
U.S. Pat. No. 3,519,054 describes a process for the production of multicolored particulate products in which two liquid streams are dried in countercurrent in the form of droplets and a dye is added to one or both liquid streams, the droplets being converted into dried multicolored particles. Ultramarine blue, for example, is used as the dye. Other examples mentioned include phthalocyanine blue, indigo, rhodamine pigment, azo ruby, chrome orange, alizarin, Indanthren® Gelb, phthalocyanine green, wool violet or anthraquinone violet.
In addition, powder-form detergents containing colored, generally green or blue, specks in the powder are known from the prior art. The colored particles are often colored detergent additives such as, for example, bleach activator particles.
DE-A-195 42 320 describes colored particles for incorporation in detergents containing surfactants, builders and/or bleaching agents and a dye which can be completely or partly destroyed by oxidation in the washing process. These colored particles are produced by a process in which the individual components and the dye are made into a slurry in water and then subjected to spray drying. In this process, however, the detergents are made up in the presence of dye solutions. As a result, the production units are heavily soiled by dyes and have to be cleaned at considerable expense.
Accordingly, the problem addressed by the present invention was to provide a process for the production of colored detergent particles for incorporation in detergents which would not have any of the disadvantages of the prior art.
Accordingly, the present invention relates to a process for the production of colored detergent particles containing surfactants, builders and/or bleaching agents and a dye, characterized in that (A) the powdering agent and the dye are made into a slurry and subjected to spray drying and (B) the colored and spray-dried powdering agent is then applied to detergent particles, process steps (A) and (B) being carried out in separate steps.
The process according to the invention is preferably carried out as a spray drying process in step (A). To this end, the powdering agent and dye are first made into a slurry. The slurry thus formed is then spray dried in a spray drying tower by introducing hot air from below. Depending on the consistency of the slurry, nuclei may also be added to accelerate particle formation. The most suitable procedure is familiar to the expert. Particularly uniformly colored homogeneous powdering agent particles can be obtained by this process step and may then be used for coloring detergents.
However, instead of the spray drying process, the powdering agent particles may also be colored by spraying the dye solution onto the powdering agent particles in known manner. In this case, however, the colored powdering agent particles have to be dried in a separate step to prevent them from agglomerating.
Parallel to the production of the colored powdering agent, uncolored detergent particles are produced. Finally, the colored powdering agents are transferred from the spray drying tower to a separate unit after step (B) of the process. In this separate unit, the uncolored detergent particles are powdered with the separately produced colored particles of powdering agent. Accordingly, powdering with the colored particles of powdering agent is carried out separately from their production.
Colored particles suitable for incorporation in a detergent in accordance with the present invention are those which, besides the dye, contain at least one other component which contributes towards the washing or cleaning performance of the detergent. The particles produced by the process according to the invention may be used as constituents of heavy-duty detergents or as heavy-duty detergents themselves, the dyes either being very quickly destroyed by oxidation in the wash liquor so that they do not give off any dye to the laundry, even at high washing temperatures, or being used to color laundry through the release of dye during the washing process, depending entirely on the choice of the dye. It is also possible to use dye mixtures which, besides dyes capable of oxidative destruction, contain blue dyes suitable for detergents which, as blueing agents, compensate for the yellowing of washed laundry.
Any dyes capable of oxidative destruction in the washing and mixtures thereof with suitable blue dyes, so-called blueing agents, are preferred. It has proved to be of advantage to use dyes which are soluble in water or in liquid organic substances at room temperature. Suitable dyes are, for example, anionic dyes, for example anionic nitroso dyes. One possible dye is, for example, naphthol green (Colour Index (CI) Part 1: Acid Green 1, Part 2: 10020), which is commercially obtainable, for example, as Basacid® Grün 970 from BASF, Ludwigshafen, and mixtures thereof with suitable blue dyes. Other suitable dyes are Pigmosol® Blau 6900 (CI 74160), Pigmosol® Grün 8730 (CI 74260), Basonyl® Rot 545 FL (CI 45170), Sandolan® Rhodamin EB400 (CI 45100), Basacid® Gelb 094 (CI 47005), Sicovit® Patentblau 85 E 131 (CI 42051), Acid Blue 183 (CAS 12217-22-0, CI Acidblue 183), Pigment Blue 15 (CI 74160), Supranol® Blau GLW (CAS 12219-32-8, CI Acidblue 221)), Nylosan® Gelb N-7GL SGR (CAS 61914-57-1, CI Acidyellow 218) and/or Sandolan® Blau (CI Acid Blue 182, CAS 12219-26-0).
In choosing the dye, it is important to ensure that it does not have an excessive affinity for the textile surfaces and, more particularly, for synthetic fibers. Another factor to be taken into account in the choice of suitable dyes is that dyes differ in their stability to oxidation. In general, water-insoluble dyes are more stable to oxidation than water-soluble dyes. The concentration of the dye in the detergents varies according to its solubility and, hence, its sensitivity to oxidation. In the case of readily water-soluble dyes, for example the Basacid® Grün mentioned above or the Sandolan® Blau also mentioned above, dye concentrations of 10
−2
to 10
−3
% by weight are typically selected. By contrast, in the case of the pigment dyes particularly preferred for their brilliance, but less readily soluble in water, for example the above-mentioned Pigmosol® dyes (Pigmosol® TAED), suitable dye concentrations in detergents are typically 10
−3
to 10
−4
% by weight.
To prevent destruction of the dye in storage, it is of advantage if the dye is stable at temperatures of up to 40° C. The stability of the detergents containing the particles produced by the process according to the invention can be increased by a low water content. In the presence of water, the dyes—in a particularly preferred embodiment—react to a certain extent with atmospheric oxygen or with oxygen present in the water. In this case, there is no need for bleaching agents to be present, which is particularly advantageous for light-duty detergents.
The dyes used for producing the colored particles should be sufficiently resistant to heat and alkalis and should not color the laundry or parts of the washing machine, even after repeated washing, and at the same time should not show any substantivity towards textile fibers so as not to color the laundry.
However, if the dyes are absorbed onto the textile fibers, the color absorbed onto the textiles should be destroyed by reaction with the oxid
Block Christian
Kruse Hans-Friedrich
Machin Antoni
Douyon Lorna M.
Harper Stephen D.
Henkel Kommanditgesellschaft auf Aktien
Murphy Glenn E. J.
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