Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Patent
1998-03-12
1999-12-07
Douyon, Lorna M.
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
510452, 510507, C11D 1102
Patent
active
059983566
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for preparing a particulate detergent composition, in particular by spray drying an aqueous slurry. Particulate detergent compositions are also disclosed.
Many granular detergents which are sold commercially comprise sodium aluminosilicate as the sole builder, or as a component of a builder system. It is known, for example from JP204098/1983, laid open on Nov. 28th 1983, that heated aqueous slurries, such as those used in conventional spray-drying processes, which comprise both sodium aluminosilicate and water-soluble silicate, cause insoluble complexes to form. These insoluble complexes are undesirable, in laundry detergents because they can result in residues on washed fabrics. Furthermore, without the silicate to act as a powder structurant, the particle size distribution of the spray-dried powder may be unacceptably broad.
In the absence of water-soluble silicate in the aqueous slurry, various other components have been proposed as powder structurants, useful to achieve a crisp, free-flowing spray-dried powder. Included amongst the powder structurants that have been suggested are film-forming polymer: polycarboxylates (for example, U.S. Pat. No. 4,379,080); polyacrylates (for example, JP204098/1983); sucrose and derivatives (for example, EP-A-0 215 637); sodium sesquicarbonate (for example, EP-A-0 242 138).
However, unless the powder structurants are required by the formulator as active ingredients, then they are an expensive processing aid.
An aqueous slurry which does not comprise either water-soluble silicate, or one of the alternative powder structurants is difficult to spray dry. In particular high water concentrations are generally needed in order to maintain the viscosity of the slurry low enough to provide crisp, free-flowing particles of the desired particle size when spray-dried. The disadvantage of high water concentrations is that the excess water must be removed during the drying step and a lot of energy is needed to do this.
WO90/04630, published on May 3rd, 1990, describes a process for preparing a carbonate containing detergent slurry comprising an alkylpolyglycoside and an alkali metal chloride. Zeolite A is suggested as one possible builder albeit in the presence of silicate (at 7% by weight in Table VI).
The object of the present invention is to avoid residue problems by substantially omitting silicate from an aqueous slurry which comprises anionic surfactant and aluminosilicate, and at the same time to provide a low viscosity slurry suitable for spray-drying to form crisp, free-flowing powder.
SUMMARY OF THE INVENTION
According to the invention this object is achieved by forming an aqueous slurry comprising water, anionic surfactant and at least 0.5% by weight of sodium aluminosilicate and which further comprises less than 5% by weight of silicate and at least 1% by weight of an inorganic salt, or a mixture of inorganic salts, and whereby the addition of the inorganic salt increases the ionic conductivity of the aqueous slurry, and subsequently drying the aqueous slurry to form the particulate detergent composition.
Preferably the inorganic salt is an alkali metal or alkaline earth metal salt, or mixtures thereof of halide, nitrate or citrate, most preferably sodium chloride.
In a more preferred embodiment of the invention the step of adding the inorganic salt raises the ionic conductivity of the aqueous slurry by at least 3 milliSiemens, and preferably by at least 5 milliSiemens.
A further aspect of the invention concerns spray-dried detergent powder compositions. Preferred compositions comprise: most preferably from 5% to 20% of anionic surfactant; 5% to 30% by weight of aluminosilicate; weight of an inorganic salt selected from the group consisting of alkali metal halides, nitrates, citrates or mixtures thereof, and preferably from 2% to 10% by weight of an alkali metal, preferably sodium, chloride; and
DETAILED DESCRIPTION OF THE INVENTION
Essential components of the compositions of the present invention are aluminosilicate builde
REFERENCES:
patent: 4102823 (1978-07-01), Matheson et al.
patent: 4415489 (1983-11-01), Kiczek et al.
patent: 4524012 (1985-06-01), Wixon
patent: 4604224 (1986-08-01), Cheng
patent: 4675127 (1987-06-01), Kickle et al.
patent: 4888119 (1989-12-01), Klewsaat
patent: 4999138 (1991-03-01), Nebashi et al.
patent: 5080820 (1992-01-01), Grecsek
patent: 5118439 (1992-06-01), Urfer et al.
patent: 5204010 (1993-04-01), Klewsaat
patent: 5447651 (1995-09-01), Karpusiewicz et al.
patent: 5565422 (1996-10-01), Del Greco et al.
Alam Zayeed
Dorset Andrew
Fitzgibbon Kay Emma
Douyon Lorna M.
Goodrich D. Mitchell
Rasser Jacobus C.
The Procter & Gamble & Company
Zerby Kim William
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