Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Solid – shaped macroscopic article or structure
Reexamination Certificate
2001-03-29
2003-08-05
Hardee, John (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Solid, shaped macroscopic article or structure
C510S471000
Reexamination Certificate
active
06602847
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a laundry treatment granule. It further extends to granular detergent compositions comprising a first granule, which comprises detergent active, and a second granule, which is according to the invention. The invention further extends to a process for manufacturing a laundry treatment granule according to the invention.
BACKGROUND OF THE INVENTION
Repeated washing of garments, particularly those comprising cotton or other cellulosic fibres, causes gradual loss of material from individual fibres and the loss of whole fibres from the fabric. These processes of attrition result in thinning of the fabric, eventually rendering it semi-transparent, more prone to accidental tearing and generally detracting from its original appearance.
Hitherto, there has been no way of minimising this kind of damage except by employing less frequent washing and use of less harsh detergent products and/or wash conditions, which obviously tends to less effective cleaning.
In laundry cleaning or treatment products, it is essential for some ingredients to be deposited onto and adhere to the fabric for them to deliver their beneficial effects. Typical examples are fabric conditioners or softeners. Nevertheless, the benefits conferred by such conventional materials do not include rebuilding the fabric. It has now been found possible to include in laundry products, agents which deposit cellulose or cellulose-like materials onto the fabric to at least partially replace the lost material of the fibre.
Our copending application WO 00/18860 describes a wide general class of fabric rebuild agents, which can rebuild fabric during a laundry operation. It has been found that, during storage of the formulation, normal conditions of humidity, temperature and alkalinity within the package are such that the fabric rebuild agent degrades so that it can become insoluble and ineffective. The present inventors have found that this problem can be overcome by formulating the fabric rebuild agent into a granule which also comprises acidic binder and a neutral filler. This granule can then be admixed to conventional powder laundry detergent compositions.
DEFINITION OF THE INVENTION
In a first aspect, the present invention provides a laundry treatment granule comprising:
(a) 50-90% by weight based on the granule of a water-soluble or water-dispersible rebuild agent for deposition onto a fabric during a laundry treatment process wherein the rebuild agent undergoes during the laundry treatment process, a chemical change by which change the affinity of the rebuild agent for the fabric is increased, said chemical change resulting in the loss or modification of one or more groups covalently bonded to be pendant to a polymeric backbone of the rebuild agent via an ester linkage, the ester-linked group(s) being selected from monocarboxylic acid esters,
(b) 0.3-10% by weight based on the granule of acidic binder, and
(c) 5-30% by weight based on the granule of neutral filler.
In a second aspect, the present invention provides a laundry treatment granule comprising:
(a) 50-90% by weight based on the granule of a water-soluble or water-dispersible rebuild agent for deposition onto a fabric during a laundry treatment process wherein the rebuild agent undergoes during the laundry treatment process, a chemical change by which change the affinity of the rebuild agent for the fabric is increased, the chemical change occurring in or to a group or groups covalently bonded to be pendant on a polymeric backbone of the rebuild agent and which backbone comprises cellulose units or other &bgr;-1,4 linked polysaccharide units, the average degree of substitution of the total of all groups pendant on the saccharide rings of the backbone being from 0.3 to 3, preferably from 0.4 to 1, more preferably from 0.5 to 0.75, most preferably from 0.6 to 0.7;
(b) 0.3-10% by weight based on the granule of acidic binder, and
(c) 5-30% based on the granule of neutral filler.
Further, the present invention extends to a process for the manufacture of a granule according to the invention, comprising mixing fabric rebuild agent, acidic binder and neutral filler in a high speed mixer/granulator. Further, the present invention extends to a granular laundry detergent composition, comprising a first granule which comprises a laundry detergent active and a second granule, which is a granule according to the present invention.
DEFINITIONS
Definition of the Invention
Throughout this specification, “average degree of substitution” refers to the number of substituted pendant groups per saccharide ring, averaged over all saccharide rings of the rebuild agent. Each saccharide ring prior to substitution has three —OH groups and therefore, an average degree of substitution of 3 means that each of these groups on all molecules of the sample, bears a substituent.
By ester linkage is meant that the hydrogen of an —OH group has been replaced by a substituent such as R′—CO—, R′SO
2
— etc to form a carboxylic acid ester, sulphonic acid ester (as appropriate) etc together with the remnant oxygen attached to the saccharide ring. In some cases, the group R′ may for example contain a heteroatom, e.g. as an —NH— group, attached to the carbonyl, sulphonyl etc group, so that the linkage as a whole could be regarded as a urethane etc linkage. However, the term ester linkage is still to be construed as encompassing these structures. The compositions according to the second aspect are not limited to those incorporating rebuild agents incorporating monocarboxylic acid ester linkages.
Optionally, the rebuild agent used in the granule may be as defined for both the first and second aspects of the invention, simultaneously.
DETAILED DESCRIPTION OF THE INVENTION
The Rebuild Agent
The exact mechanism by which the rebuild agents exert their effect is not fully understood. Whether or not they can repair thinned or damaged fibres is not known. However, they are capable of replacing lost fibre weight with deposited and/or bonded material, usually of cellulosic type. This can provide one or more advantages such as repair or rebuilding of the fabric, strengthening of the textile or giving it enhanced body or smoothness, reducing its transparency, reducing fading of colours, improving the appearance of the fabric or of individual fibres, improved comfort during garment wear, dye transfer inhibition, increased stiffness, anti-wrinkle, effect and ease of ironing.
In the case of those rebuild agents having a cellulose backbone and pendant ester groups, without being bound by any particular theory or explanation, the inventors have conjectured that the mechanism of deposition is as follows.
Cellulose is substantially insoluble in water. Attachment of the ester groups causes disruption of the hydrogen bonding between rings of the cellulose chain, thus increasing water solubility or dispersibility. In the treatment liquor, it is believed that the ester groups are hydrolysed, causing the affinity for the fabric to increase and the polymer to be deposited on the fabric.
The rebuild agent material used in the present invention is water-soluble or water-dispersible in nature and in a preferred form comprises a polymeric backbone having one or more pendant groups which undergo the chemical change to cause an increase in affinity for fabric.
The weight average molecular weight (M
w
) of the rebuild agent (as determined by GPC) may typically be in the range of 500 to 2,000,000 for example 1,000 to 1,500,000. Preferably though, it is from 1,000 to 100,000, more preferably from 5,000 to 50,000, especially from 10,000 to 15,000.
By water-soluble, as used herein, what is meant is that the material forms an isotropic solution on addition to water or another aqueous solution.
By water-dispersible, as used herein, what is meant is that the material forms a finely divided suspension on addition to water or another aqueous solution. Preferably though, the term “water-dispersible” means that the material, in water at pH 7 and at 25° C., produces a solution or a disper
Emery William Derek
Jones Christopher Clarkson
Bornstein Alan A.
Hardee John
Unilever Home & Personal Care USA , division of Conopco, Inc.
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