Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
2002-12-05
2003-09-23
Hardee, John (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S463000
Reexamination Certificate
active
06624136
ABSTRACT:
The present invention relates to water-dispersible granules comprising at least one fragrance in a water-soluble or water-dispersible organic polymer matrix, to a process for preparing them, to their use as fragrancing agents in detergent or cosmetic compositions and to laundry detergent compositions or cosmetic compositions comprising said particles.
The fragrancing of detergent washing compositions, in particular for washing laundry, requires a certain number of constraints that are more or less important depending on the technico-economic and marketing objectives of the formulator.
One of the first problems posed is to find a suitable means of adding and distributing the liquid fragrance on the detergent powder.
The fragrance is generally finely sprayed, continuously, onto the complete formulated powder, which transits in any transporter, between the site of manufacture and the site of packaging. Pneumatic transporters can be used for this operation, or alternatively “air lift” systems. It is necessary for the washing product formulated to be sufficiently cooled, in particular when the manufacturing process is a spraying process, and for the mixing system to permit only a minimal loss of fragranced substance, which is among the most expensive components of the formulation. Respecting the dosage (percentage of fragrance relative to the powder) is one of the factors that is difficult to control and which needs investigating to be improved both on account of the problems of cost and on account of the problems of consistency of quality.
Formulating the composition as a particulate solid can represent a first improvement to this level of process for manufacturing washing products.
Another problem of the fragrancing of washing products is that of the stability of the fragrance (and of all of the “notes” it releases) during storage of the washing product in its packaging.
Specifically, the components of washing products are themselves very varied and their chemical natures are very diverse and may be corrosive, or even incompatible, with the fragranced composition, which comprises chemically fragile components.
Modern washing products often contain bleaching systems based on products which release hydrogen peroxide, followed by active oxygen. This is the most destabilizing factor for the fragrances.
The alkalinity of the compositions is also a factor with regard to degradation of the fragrance.
Highly absorbent products such as silicas, clays or zeolites can selectively and to a greater or lesser extent absorb the fragrance or one of its components and thereby contribute toward modifying or impairing it.
Similarly, the water of crystallization, free water, surfactants and sequestering agents, which are always present in detergent compositions, may interfere negatively with the fragranced compositions.
A third problem, or a third requirement, encountered in the field of fragrancing washing products is the fact that the perception of the odor chosen, which is one of the methods by which the purchaser recognizes the washing product, should be effective in all the lifecycles of the washing product, and even beyond.
In particular, the odor of the fragrance, or at the very least a fraction of this odor, should be perceptible in the shop in which the washing product is presented for purchase, during the shelf life of the packet (even opened), during the washing itself, from the washing machine, during the operations of drying, ironing and tidying away of the washed articles, in the wardrobe, and finally during the wearing or use of the laundry.
Such a series of requirements is obviously not easy to satisfy, but among the means which need to be deployed to attend to this satisfaction, coating and encapsulation, which improve the stability on storage and can under certain conditions allow a release of the fragrance during washing, are one of the most important and most effective means.
Several methods for formulating fragrances in solid form have been attempted in the past or very recently by fragrance manufacturers or by washing product manufacturers to partially or totally solve these problems.
One of the first means is to use the absorbent properties of certain porous supports, such as silicas, clays, natural or synthetic zeolites, starches, carboxymethylcellulose, urea, soluble inorganic phosphates, etc.
However, there are numerous drawbacks with these formulation methods, in particular the fact of dividing and spreading the fragrance over very large contact surfaces, and thus of increasing the risks of oxidation at the same time as the area for exchange between the fragrance and the air, and also the risk of selectively retaining one or more components, with restitution of a modified odor.
Simple absorption allows formulation in solid form, but is often insufficient for protecting the fragrance during storage. There should also be recourse to a coating of the fragrance/support assembly.
Another formulation method is the use of products of specific molecular structure making it possible to create a cavity for receiving the fragrances, for example products such as cyclodextrins. The drawback, besides the cost, is the difficulty in introducing complex compositions based on products of very different and dissimilar molar mass and steric bulk.
Organic matrices composed of PEG or of paraffins whose molecular mass is sufficient for them to be solid at ordinary temperature, have also been proposed for solidifying fragranced compositions, with advantages but also drawbacks, in particular that of only partially releasing the fragrance, or the fact that molten phases of the coating products need to be used.
Sophisticated methods that are difficult to control, such as the techniques of microencapsulation by interfacial polycondensation, have also been put forward for obtaining encapsulated fragrances, but their cost and their complexity have not facilitated their development.
Finally, the use of preformed microcapsules, either mineral or polymeric, which are optionally mechanically disintegrable, have also been envisaged, without great commercial success, probably for economic reasons.
The Applicant has found a water-dispersible solid formulation for liquid fragrances, by encapsulation with a protective matrix which becomes located outside the droplets of finely divided fragrance; in this way, said matrix coats the fragrance, protects it and at the same time allows it to change to solid form.
A first subject of the invention consists of water-dispersible granules comprising
at least one hydrophobic fragrance (P), in the form of droplets, which is finely divided in and encapsulated by a water-soluble or water-dispersible solid organic matrix (MO) chosen from
water-soluble or water-dispersible polypeptides (PP) of plant or synthetic origin
polyelectrolytes (PE) belonging to the family of weak polyacids
or mixtures thereof,
and at least one emulsifier (AE) at the droplet/matrix interface.
For good implementation of the invention, said water-dispersible granules comprise
from 5% to 90%, preferably from 25% to 70%, of their weight of fragrance (P),
from 5% to 90%, preferably from 25% to 70%, of their weight of water-soluble or water-dispersible organic matrix (MO),
from 0.02% to 20%, preferably from 0.1% to 10%, of their weight of emulsifier (AE), said percentages being expressed by weight of solids.
Said droplets can have a mean particle size from about 0.1 &mgr;m to 10 &mgr;m, preferably from about 0.2 &mgr;m to 5 &mgr;m.
The term “fragrance” means either a fragranced essence or, more generally, a complex composition obtained using many odoriferous products as a mixture and excipient products which ensure its homogeneity.
Said fragrances according to the invention are isotropic and hydrophobic compounds. Their solubility in water at pH 7 does not exceed 10% by weight.
The mixture of odoriferous products can comprise a large number of constituents, chosen so as to obtain the desired fragranced notes for the intended use, public and market. Natural products (for example plant or animal essences obtai
Guerin Giles
Joubert Daniel
Morvan Mikel
Hardee John
Rhodia Chimie
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