Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
1999-01-25
2002-04-23
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S312000, C510S313000, C510S349000, C510S360000, C510S376000, C510S470000, C510S473000, C510S507000, C510S511000
Reexamination Certificate
active
06376454
ABSTRACT:
The present invention relates to the field of coated particulate detergent components or compositions.
It is known that the flow properties of granular detergents can be improved by “dusting” them with finely divided particulates, such as zeolite. U.S. Pat. No. 3,868,336 discloses detergent compositions dusted with from 0.5% to 15% by weight of water-insoluble flow-promoting agents. However, dusting with finely divided particulates does not provide any benefit for detergent dispensing, it can also make the final detergent product dusty, and it does not always provide adequate improvements in the flow properties.
Other coating agents, applied as liquids, melts or solutions are also known in the field of detergents. GB-A-1 395 006, published on May 21, 1975, discloses cellulosic polymers as coating agents for detergent components. Sucrose and glucose are also disclosed therein, as plasticizers with dextrin. However cellulosic polymers and sugars are nowhere disclosed in combination as coating agents for detergent components.
The disadvantage of coating a detergent with cellulosic polymer on its own is that the film formed is slow to dry, and can form a coating that is sticky.
Mixtures of cellulosic polymers and sugars are known coating agents in the pharmaceutical field. JP-51 123 815, published Oct. 29, 1976, and EP-A-0 551 700, published on Jul. 21, 1993 both disclose combinations of cellulosic polymer and sugars as coating agents for pharmaceutical products, but there is no suggestion that these coatings are suitable for use with detergents.
The object of the present invention relates the application of certain coatings to particulate detergent components or compositions to improve free-flow properties, improve dispensing, avoid dust formation and improve stability of storage sensitive materials.
A further object of the present invention is to provide a fast-drying coating which forms a continuous film around the particles of the detergent component or composition.
SUMMARY OF THE INVENTION
The object of the invention is achieved by a two-step coating process, wherein the first coating step comprises the process of mixing the detergent composition or component with a finely divided particulate material which is preferably aluminosilicate, and the second coating step comprises the process of applying a coating agent. Suitable coating agents comprise from 5% to 95%, preferably from 10% to 60% by weight of cellulosic polymer; from 5% to 95%, preferably from 60% to 90% by weight of sugar; and optionally, from 1% to 30% by weight of plasticizer.
Preferred detergent components include nonionic surfactant, in particular polyhydroxy fatty acid amide; and bleach activators.
DETAILED DESCRIPTION OF THE INVENTION
The term “cellulosic polymer” as used herein means polymers that are built up from derivatives of cellulose. Cellulose is a polysaccharide made from &bgr;-D-glucose units linked together. In the derivatives one or more of the hydroxyl groups are replaced by other groups e.g. methyl, ethyl, propyl.
Preferred cellulosic polymers include methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methylhydroxymethyl cellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose and ethyl hydroxyethyl cellulose.
The term “sugar” as used herein is a generic term for a class of carbohydrates which are usually crystalline and sweet by nature, and which are water soluble. Sugars are formed form glucose and fructose units which are sugars in their own right. Preferred sugars include glucose, fructose, galactose, sucrose, maltose, lactose, sorbitol, manitol, rafinose, trehalose.
The term “plasticizer” as used herein is a material that is added to the original material for the purpose of softening the original material, and make it more flexible. Preferred plastisrzers include polyethylene glycol having a molecular weight of between 200 and 20000, polypropylene glycol, glycerol, triacetin
The second coating agent may be applied in any conventional coating apparatus. Suitable apparatus include pan coater; rotating drum continuous coater; spray fluidised granular, or spray fluidised continuous belt. In a particular embodiment of the present invention the components of the second coating agent are dissolved or dispersed in a suitable solvent or carrier medium. A preferred solvent is water, and an aqueous solution may be prepared which is typically 5% to 40% solids.
The solution or dispersion may then be sprayed on to the detergent component or composition. The proportion of the second coating agent needed to provide a suitable coating layer depends on various parameters, such as the surface characteristics of the detergent component or composition, and will be easily determined by experiment. Preferably the second coating agent is from 0.1% to 30% of the finished product, more preferably, from 1% to 5%, and most preferably about 2%.
In the present invention, the detergent component or composition is coated with a finely divided particulate material prior to coating with the second coating agent.
The detergent component or composition is coated with a first coating agent comprising up to 35%, preferably from 1% to 20% by weight of finely divided particulate material prior to the application of the second coating agent. The first coating agent has two purposes. Firstly it allows the detergent particles to be separated (if they are sticky) so that each one can be fully coated. Secondly it gets combined into the second coating agent and adds additional structure to the coating.
Finely divided particulate materials useful herein include aluminosilicates having the empirical formula:
M
z
(
zAlO
2
)
y
]·x H
2
O
wherein z and y are integers of at least 6, the molar ratio of z to y is in the range from 1.0 to about 0.5, and x is an integer from about 15 to about 264. Useful aluminosilicate ion exchange materials are commercially available. These aluminosilicates can be crystalline or amorphous in structure and can be naturally-occurring aluminosilicates or synthetically derived. A method for producing aluminosilicate ion exchange materials is disclosed in U.S. Pat. No. 3,985,669, Krummel et al, issued Oct. 12, 1976. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations zeolite A, zeolite P(B), zeolite MAP, zeolite X and zeolite Y. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:
Na
12
[(AlO
2
)
12
(SiO
2
)
12
]·x H
2
O
wherein x is from about 20 to about 30, especially about 27. This material is known as zeolite A. Dehydrated zeolites (x=0-10), and “overdried” zeolites (x=10-20) may also be used herein. The “overdried” zeolites are particularly useful when a low moisture environment is required, for example to improve stability of detergent bleaches such as perborate and percarbonate. Preferably, the aluminosilicate has a particle size of about 0.1-10 micrometers in diameter. Preferred ion exchange materials have a particle size diameter of from about 0.2 micrometers to about 4 micrometers. The term “particle size diameter” herein represents the average particle size diameter by weight of a given ion exchange material as determined by conventional analytical techniques such as, for example, microscopic determination utilizing a scanning electron microscope. The crystalline zeolite A materials herein are usually further characterized by their calcium ion exchange capacity, which is at least about 200 mg equivalent of CaCO
3
water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which generally is in the range of from about 300 mg eq./g to about 352 mg eq./g. The zeolite A materials herein are still further characterized by their calcium ion exchange rate which is at least about 2 grains Ca
++
/gallon/minute/gram/gallon (0.13 g Ca
++
/litre/minute/gram/litre) of aluminosilicate (anhydrous basis), and generally lies within the range of from about 2 gra
Eggersmann Markus
McKee Zoë
Schamp Koen Mariette Albert
Douyon Lorna M.
Dressman Marianne
Miller Steven W.
William Zerby Kim
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