Compositions – Electrolytes for electrical devices
Patent
1993-02-03
1994-08-02
Albrecht, Dennis
Compositions
Electrolytes for electrical devices
252 95, 252174, 25217413, 25218212, 25218223, 25218228, 25218229, 25218625, 25218626, 25218631, 25218638, C11D 1831, C11D 3395, D06L 302, D06L 316
Patent
active
053343247
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to new pourable and free-flowing granules containing bleach activators for washing laundry in a binder phase as their principal constituent, the binder phase predominantly containing surfactants which are solid at room temperatures and moderately elevated temperatures, for example up to about 40.degree. C. The invention also relates to a process for the production of the new bleach activator granules.
Inorganic peroxy compounds which dissolve in water with release of hydrogen peroxide, such as sodium perborate and sodium peroxycarbonate, have long been used as oxidizing agents for disinfection and bleaching purposes. The oxidizing effect of these substances in dilute solutions is governed to a large extent by temperature. Thus, with perborate in alkaline bleach liquors, sufficiently rapid bleaching of soiled textiles is only achieved at temperatures above 60.degree. C. At lower temperatures, the oxidizing effect of the inorganic per compounds can be improved by addition of activators for which numerous proposals have been published in the literature. The addition of these activators can increase the bleaching effect of aqueous peroxide solutions to such an extent that they are active at temperatures of only 30.degree. to 60.degree. C., i.e. at the temperatures required for the washing of delicate fabrics.
However, these activators, for example from the class of N- and O-acyl compounds, are highly sensitive to hydrolysis, above all in the presence of the alkaline ingredients typically used in detergents. The resulting problems for the stability of the laundry detergents in storage are aggravated by the fact that the activators are often poorly soluble in water so that very fine-particle materials with rapid dispersibility should be used. However, this fineparticle form promotes greater hydrolysis of the activators in storage on account of the increased surface.
Discussion of Related Art
In practice, the situation is remedied by adding the bleach activator to the dry detergent mixtures in the form of separately produced granules, the agglomerates of fine bleach particles being coated with auxiliaries. Various organic and inorganic substances have been proposed as granulation aids and coating materials for such activator granules. More particularly, the use of surfactant compounds solid at room temperature from the classes of anionic, cationic and/or nonionic surfactants, polymeric materials or waxes is well known. Thus, European patent application EP 37 026 (Henkel) describes the production of pourable, uniformly coated bleach activator granules containing more than 90% active substance. In this process, 90 to 98% by weight of a powder-form bleach activator from the class of N-acylated amines, amides, diketopiperazines and glycolurils are mixed with 10 to 2% by weight of a powder-form granulation aid. The dry premix is then moistened with an aqueous solution of the granulation aid, after which the mixture is granulated. The moist granules are then dried to low residual water contents. The granulation aids used are, in particular, water-soluble cellulose ethers, water-soluble starch or water-soluble starch ethers.
Referring first to the prior art, European patent application EP 6 655 (P & G) describes the use of organic solids melting at 30.degree. to 60.degree. C. as agglomeration aids for the production of bleach activator granules and then discusses in detail the use of nonionic surfactant compounds from the class of linear or branched C.sub.10-24 fatty alcohol ethoxylates, the class of C.sub.8-18 alkylphenol ethoxylates or polyethylene glycols having relative molecular weights above 4000 as granulation aids. The alcohol ethoxylates are compounds which are solid under normal conditions and contain at least 15 EO groups per mol alcohol, the use of corresponding components containing approximately 20 EO groups being preferred. These solid nonionic surfactants may be used together with liquid or paste-form nonionics having a rela
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Jacobs Jochen
Raehse Wilfried
Zeise Christiane
Albrecht Dennis
Grandmaison Real J.
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Szoke Ernest G.
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