Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – With oxygen or halogen containing chemical bleach or oxidant...
Reexamination Certificate
1999-12-01
2001-03-20
Gupta, Yogendra (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
With oxygen or halogen containing chemical bleach or oxidant...
C510S307000, C510S394000, C510S516000
Reexamination Certificate
active
06204235
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to bleaching agents and disinfectants and, more particularly, to active chlorine preparations containing optical brighteners in microencapsulated form.
2. Discussion of Related Art
In Mediterranean countries and also in the United States, cold water is still predominantly used for washing laundry. The effect of this is that conventional bleaching agents, for example perborates or percarbonates, are hardly used because they do not develop any particular activity at temperatures around 20° C. For this reason, liquid bleaches—generally surface—active preparations containing up to 10% by weight of hypochlorite—are normally added to the wash liquor. Comparable preparations are also used for cleaning and disinfecting hard surfaces. An overview of hypochlorite liquors was published, for example, by J. Josa and M. Osset in Jorn. Corn. Esp. Deterg. 27, 213 (1997).
To counteract the yellowing of laundry, optical brighteners are added to the bleaching compositions. These auxiliaries are absorbed onto the fibers and convert invisible UV radiation into visible longer-wave light. The ultraviolet light absorbed from sunlight is re-emitted in the form of pale bluish fluorescence, i.e. in the complementary color to the yellowing. The optical brighteners used are generally dyes which are readily oxidized in a chlorine-containing environment and, as a result, lose their properties.
Microcapsules
“Microcapsules” are understood to be aggregates which contain at least one solid or liquid core surrounded by at least one continuous shell, more particularly a shell of polymer(s). They are normally finely dispersed liquid or solid phases coated with film-forming polymers, in the production of which the polymers are deposited onto the material to be encapsulated after emulsification and coacervation or interfacial polymerization. The microscopically small capsules, also known as nanocapsules, can be dried in the same way as powders. Besides single-core microcapsules, there are also multiple-core aggregates, also known as microspheres, which contain two or more cores distributed in the continuous shell material. In addition, single-core or multiple-core microcapsules may be surrounded by an additional second, third etc. Shell. Single-core microcapsules with a continuous shell are preferred. The shell may consist of natural, semisynthetic or synthetic materials. Natural shell materials are, for example, gum arabic, agar agar, agarose, maltodextrins, alginic acid and salts thereof, for example sodium or calcium alginate, fats and fatty acids, cetyl alcohol, collagen, chitosan, lecithins, gelatin, albumin, shellac, poly-saccharides, such as starch or dextran, sucrose and waxes. Semisynthetic shell materials are inter alia chemically modified celluloses, more particularly cellulose esters and ethers, for example cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose and carboxymethyl cellulose, and starch derivatives, more particularly starch ethers and esters. Synthetic shell materials are, for example, polymers, such as polyacrylates, polyamides, polyvinyl alcohol or polyvinyl pyrrolidone.
Although they may be produced in any shape, the microcapsules are preferably substantially spherical. Their diameter along their largest spatial dimension may be between 10 nm (visually not discernible as a capsule) and 10 mm, depending on the optical brighteners present in their interior and the application envisaged. Visible microcapsules between 0.1 mm and 7 mm and, more particularly, between 0.4 mm and 5 mm are preferred. Microcapsules invisible to the naked eye have a diameter of preferably 20 to 500 nm and more preferably 50 to 200 nm. The microcapsules may be obtained by known processes, of which coacervation and interfacial polymerization are the most important. Any commercially available surfactant-stable microcapsules may be used as the microcapsules, including for example the commercial products (the shell material is shown in brackets) Hallcrest Microcapsules (gelatin, gum arabic), Coletica Thalaspheres (maritime collagen), Lipotex Millicapsein (alginic acid, agar agar), Induchem Unispheres (lactose, microcrystalline cellulose, hydroxypropylmethyl cellulose), Unicerin C30 (lactose, micro-crystalline cellulose, hydroxypropylmethyl cellulose), Kobo Glycospheres (modified starch, fatty acid esters, phospholipids), Softspheres (modified agar agar) and Kuhs Probiol Nanospheres-(phospholipids).
The active substances are released from the microcapsules by mechanical, thermal, chemical or enzymatic destruction of the shell, normally during the use of the preparations containing the microcapsules. In the case of the bleaching agents normally used in undiluted form, they are preferably released by mechanical action, more particularly by mechanical forces to which the microcapsules are exposed during dosing, pump-circulation or spinning in the washing machine or during the cleaning and disinfection of hard surfaces. In one preferred embodiment of the invention, the preparations contain the same microcapsules or different microcapsules in quantities of 0.1 to 10% by weight, more preferably in quantities of 0.2 to 8% by weight and most preferably in quantities of 0.5 to 6% by weight.
Optical Brighteners
The optical brighteners which are used in microencapsulated form in accordance with the present invention are preferably those which are otherwise unstable in active chlorine preparations. Typical examples of suitable optical brighteners are derivatives of diaminostilbene disulfonic acid and alkali metal salts thereof. Suitable optical brighteners are, for example, derivatives of 4,4′-diamino-2,2′-stilbene disulfonic acid (flavonic acid), such as in particular the salts of 4,4′-bis-(2-anilino4-morpholino-1,3,5-triazinyl-6-amino)-stillbene-2,2′-disulfonic acid or compounds of similar structure which, instead of the morpholino group, contain a diethanolamino group, a methylamino group, an anilino group or a 2-methoxyethylamino group. Other brighteners which may be present are those of the substituted diphenyl styryl type, for example alkali metal salts of 4,4′-bis-(2-sulfostyryl)-diphenyl, 4,4′-bis-(4-chloro-2-sulfostyryl)-diphenyl or 4-(4-chlorostyryl)4′-(2-sulfostyryl)-diphenyl, methyl umbelliferone, coumarin, dihydroquinolinone, 1,3-diaryl pyrazoline, naphthalic acid amide, benzoxazole, benzisoxazole and benzimidazole systems linked by CH═CH bonds, heterocycle-substituted pyrine derivatives and the like. Mixtures of the brighteners mentioned above may also be used. The potassium salt of 4,4′-bis-(1,2,3-triazoly(2)-stilbine-2,2-sulfonic acid marketed under the name of Phorwite® BHC 766 is preferred. The microcapsules generally contain the optical brighteners in quantities of 1 to 75% by weight, preferably in quantities of 10 to 60% by weight and more preferably in quantities of 25 to 50% by weight, based on the weight of the capsules. In addition, it is of advantage if, besides the usual brighteners in the usual quantities, for example between 1 and 5% by weight and preferably between 2 and 3% by weight, the microcapsules also contain small quantities of a blue dye. Particularly preferred brighteners or dyes are naphthotriazole stilbene sulfonic acid, for example in the form of its sodium salt (Tinopal® RBS 200) and tetrabenzotetraazaporphine (Tinolux® BBS), distyryl bisphenyl bis-(triazinylamino)-stilbene disulfonic acid (Tinopal® CDS-X) and, in particular, 4,4′-bis-(2-sulfostyrene)-biphenyl disodium salt (Tinopal® CBS-X, products of Ciba).
Sequestering agents
If the preparations are used for treating fabrics, it is advisable to add to them electrolytes which act as sequestrants for heavy metal ions and which therefore counteract yellowing of the fabrics. Suitable sequestering agents are, for example, silicates, phosphonic acids and phosphonates, polyacrylic acid compounds, alkali metal carbonates, such as sodium carbonate, lignin sulfonates
Jimenez Carrillo Lidia
Mendoza Cruz Mercedes
Osset Hernandez Miguel
Gupta Yogendra
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Murphy Glenn E.J.
Petruncio John M
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