Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
1998-09-21
2001-09-18
Gupta, Yogendra N. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S349000, C510S421000, C510S356000, C510S360000, C510S470000, C510S511000, C510S438000
Reexamination Certificate
active
06291420
ABSTRACT:
The present invention relates to a system based on at least one liquid, waxy or pasty nonionic surfactant and on an alkali metal silicate, the said system being in the form of granules or a stable aqueous dispersion. This system can be used as a constituent of detergent compositions in liquid or powder form. The invention is also directed towards the detergent compositions in powder or liquid form based on the said system.
It is known to convert organic materials, in particular surfactants, that are liquid under standard temperature and pressure conditions, into pulverulent products by adsorption and/or absorption onto a solid support, generally a more or less porous inorganic support.
The two-component product obtained has the drawback of only having a very low concentration of organic material, since the support takes up a considerable amount of space.
This is due to the fact that support products are relatively non-porous and thus adsorb poorly. Thus, nonionic surfactant/sodium carbonate, nonionic surfactant/sodium sulphate or nonionic surfactant/sodium silicate two-component mixtures in powder form contain not more than 30% of their weight of organic material considered.
The use of more porous supports such as precipitation silicas, clays, sodium silicoaluminates, magnesium or calcium silicates, crystalline aluminosilicates or amorphous aluminosilicates such as zeolites makes it possible to obtain mixtures with a higher concentration of organic material, which can contain up to 65% of their weight of organic material.
However, these supports have the drawback of being insoluble in water, which can pose problems in the use envisaged.
Another solution consists in using a crosslinked absorbent organic polymer (absorbent crosslinked polyacrylate, etc.) or a hydrocolloid (starch, guar, etc.); however, this is more expensive and can also have drawbacks as regards denaturing interactions between the support and the organic material.
The Applicant has found a means for preparing stable dispersions of nonionic surfactants, the continuous phase of which consists of a concentrated aqueous solution of alkali metal silicate and the dispersed phase of which consists of droplets or particles of liquid, waxy or pasty nonionic surfactant, these dispersions being converted, by simple drying, into granules by encapsulation of the droplets or particles of nonionic surfactant in a rigid shell of alkali metal silicate.
This solid presentation form has the advantage of leading to a soluble product which is readily available, stable on storage, able to contain high contents of nonionic surfactant and able to provide controlled release of the said surfactant.
The system formed by the nonionic surfactant and the alkali metal silicate, whether it is in the form of granules or an aqueous dispersion, has detergent properties and detergence-adjuvant (“builder”) properties which give it the capacity to be used as a constituent of liquid or solid, household or industrial detergent compositions, in particular for washing laundry.
According to the invention, this is a system (S), in the form of granules or an aqueous dispersion, based on at least one liquid, waxy or pasty nonionic surfactant and on an alkali metal silicate, this system being characterized in that it can be obtained
by placing in dispersion
in a concentrated aqueous solution of an alkali metal silicate as continuous liquid phase,
of at least one liquid, pasty or waxy nonionic surfactant (NIA) which is immiscible or poorly miscible with the said concentrated aqueous solution of alkali metal silicate,
using at least one nonionic or anionic surfactant (TAS) which is compatible with the said concentrated solution of alkali metal silicate and which is capable of dispersing the liquid, pasty or waxy nonionic surfactant(s) (NIA) in the said concentrated solution of alkali metal silicate,
and optionally by drying the dispersion formed, until a rigid shell of alkali metal silicate encapsulating the said droplets or particles of liquid, pasty or waxy nonionic surfactant(s) (NIA).
The expression “liquid, pasty or waxy nonionic surfactant (NIA) which is immiscible or poorly miscible with an aqueous solution of alkali metal silicate” is understood to refer to any nonionic surfactant which, in its natural state, is in liquid, pasty or waxy form under standard temperature and pressure conditions (generally a temperature of about −10 to 45° C. and a pressure of about 0.8 to 1.2 bar) and which is not capable of being dissolved, being hydrated (by salvation of the hydrophilic part) or of being hydrolysed to more than 10% of its weight in the said concentrated silicate solution.
Among the liquid, pasty or waxy nonionic surfactants (NIA), mention may be made in particular of alkoxylated nonionic surfactants.
Mention may be made in particular of those usually used in the field of detergents for washing laundry, such as
polyoxyalkylenated (polyethoxyethylenated, polyoxypropylenated, polyoxybutylenated) alkylphenols whose alkyl substituent is C
6
-C
12
and containing from 5 to 25 oxyalkylene units; by way of example, mention may be made of Triton X-45, X-114, X-100 or X-102 sold by Rohm & Haas Co. and Igepal NP2 to NP17 from Rhône-Poulenc;
polyoxyalkylenated C
8
-C
22
aliphatic alcohols containing from 1 to 25 oxyalkylene (oxyethylene, oxypropylene) units; by way of example, mention may be made of Tergitol 15-S-9 and Tergitol 24-L-6 NMW sold by Union Carbide Corp., Neodol 45-9, Neodol 23-65, Neodol 45-7 and Neodol 45-4 sold by Shell Chemical Co., Kyro EOB sold by The Procter & Gamble Co., Synperonic A3 to A9 from ICI and Rhodasurf IT, DB and B from Rhône-Poulenc;
alkoxylated terpenic hydrocarbons such as ethoxylated and/or propoxylated &agr;- or &bgr;-pinenes containing from 1 to 30 oxyethylene and/or oxypropylene units;
products resulting from the condensation of ethylene oxide or of propylene oxide with propylene glycol or ethylene glycol, with a weight-average molecular mass of about 2000 to 10,000, such as the Pluronic products sold by BASF;
products resulting from the condensation of ethylene oxide or of propylene oxide with ethylenediamine, such as the Tetronic products sold by BASF;
C
8
-C
1
ethoxylated and/or propoxylated fatty acids containing from 5 to 25 ethoxylated and/or propoxylated units;
ethoxylated fatty amides containing from 5 to 30 units;
ethoxylated amines containing from 5 to 30 ethoxylated units;
alkoxylated amidoamines containing from 1 to 50, preferably from 1 to 25, most particularly from 2 to 20, oxyalkylene (preferably oxyethylene) units; etc.
Among the concentrated solutions of alkali metal silicate, mention may be made of aqueous solutions of alkali metal silicate with an SiO
2
/M
2
O molar ratio which can range from 1.5 to 4, preferably from 2 to 3.5, and containing from about 35 to 50% of active material, M representing sodium or potassium; mention may be made most particularly of commercial solutions of sodium silicate with a ratio of about 2 containing from about 45 to 50% of active material, as well as those of sodium silicate with a ratio of about 3 containing from about 35 to 40% of active material.
The small amounts of free water present in these concentrated silicate solutions are not sufficient to dissolve, hydrate (solvate) or hydrolyse the nonionic surfactants (NIA).
The dispersing of the surfactant(s) (NIA) in the said concentrated solution of alkali metal silicate can be carried out using any nonionic or anionic surfactant which is compatible with the concentrated solution of alkali metal silicate, i.e. which can be dissolved or hydrated (solvated) giving an isotropic homogeneous phase with the concentrated solution of alkali metal silicate. This operation can be carried out in particular using at least one nonionic or anionic surfactant (TAS) whose hydrophilic part contains one or more saccharide unit(s).
The said saccharide units generally contain from 5 to 6 carbon atoms. These can be derived from sugars such as fructose, glucose, mannose, galactose, talose, gulose, allose, altose, idose, arabinose, xylose,
Guerin Gilles
Joubert Daniel
Phan Charles
Wong Kenneth
Burns Doane Swecker & Mathis L.L.P.
Gupta Yogendra N.
Mruk Brian P.
Rhodia Chimie
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