Patent Application
20070191254
The present invention relates to a composition comprising an anionic polysaccharide, for caring for articles made of textile fibers (“textile care”), especially cotton-based textiles, which are in particular colored.
The expression “care of articles made of textile fibers, in particular fabrics” means the protection of these articles against physical or chemical degradation phenomena, especially the protection of the colors of colored articles, and/or the provision of benefits thereto, for instance softening and/or crease-resistance properties.
The machine washing of fabrics leads to a physical and chemical degradation of the fibers and most particularly of cotton fibers. The alkalinity delivered by detergents and also by certain specific compounds such as oxidizing substances (perborate or percarbonate) or certain enzymes may be the cause of the chemical degradation of cotton fibers. However, it is generally the combination of the chemical and mechanical actions which leads to degradation of the fibers. The mechanical action is produced during the washing, rinsing, spin-drying or tumble-drying, when the latter takes place in a tumble dryer. This degradation of the fibers leads to the formation of fibrils at the surface of the textile which end up causing colored textiles to lose their radiance. This degradation also induces a decrease in the strength of the textile which, at the extreme, may lead to tearing of the fabrics. This degradation of the textiles may be evaluated quantitatively either by a loss of the colors of colored textiles or by a reduction in the tear strength of the textile. It is generally necessary to carry out 10 to 20 cumulative machine washes in order to perceive this type of degradation.
Cleaning in a washing machine, which systematically includes a spin-drying operation, also leads to creased fabrics, which is accentuated during the tumble-drying stage, in particular by the formation of inter-fiber hydrogen bonds. It is thus necessary to iron the fabrics in order to make them look presentable.
In order to reduce the degradation of the fibers during washing or rinsing, the suppliers of chemical products or detergents have made use of changes in detergent formulations or have used certain specific additives.
Mention may be made in particular of detergents comprising no oxidizing system, but which have reduced cleaning capacities.
Silicone-based compounds have also been used, and in particular aminosilicones (U.S. Pat. No. 4,585,563; WO 92/07927; WO 98/39401).
The Applicant has found that the use, in compositions for treating articles made of textile fibers, especially cotton-based articles, which are in particular colored, of certain anionic polysaccharides of high molecular mass that are soluble under the working conditions in aqueous or wet medium of said compositions, makes it possible to prevent the degradation of these articles, makes it possible to protect the colors and/or gives these articles crease-resistance and/or softening properties.
Such compositions may especially be compositions for washing and/or rinsing and/or softening fabrics, for destaining fabrics before washing (“prespotting”), for tumble-drying wet fabrics in a tumble dryer or for ironing fabrics.
A first subject of the invention consists of a composition for caring for articles made of textile fibers (“fabric care”), characterized in that it comprises at least one anionic polysaccharide with a weight-average molar mass of greater than 250 000 and preferably greater than 500 000,
the native skeleton of which is a polysaccharide formed from
The weight-average molar mass of said anionic polysaccharides may be up to 2 000 000.
The weight-average molar mass Mw of said anionic polysaccharides may be measured by size exclusion chromatography. The measurement is performed in water at pH 9-10 containing 0.1 M LiCl and 2/10000 of NaN3.
The weight-average molar mass Mw is established directly in a manner that is known via the light-scattering values.
The degree of substitution or of modification DSi corresponds to the average number of hydroxyl functions in the anhydrohexose and/or anhydropentose units that are substituted or modified with said anionic or anionizable group(s), per anhydrohexose and/or anhydropentose unit.
Said ionic or ionizable groups are linked to the carbon atoms of the sugar skeleton either directly or via —O— bonds.
According to one embodiment variant of the invention, said anionic polysaccharide may also contain at least one nonionic group.
Said nonionic groups are linked to the carbon atoms of the sugar skeleton either directly or via —0— bonds.
The presence of such groups is expressed as the number of moles of substitution MS, i.e. as the average number of moles of precursor of said nonionic substituent that have reacted per anhydrohexose and/or anhydropentose unit.
If said precursor is incapable of forming new reactive hydroxyl groups (for example alkylation precursor), the degree of substitution or of modification by all the anionic or anionizable and nonionic groups is less than 3, by definition.
If said precursor is capable of forming new reactive hydroxyl groups (for example hydroxyalkylation precursor), the number of moles of substitution MS is theoretically not limited; it may be, for example, up to 6 and preferably up to 2.
Among the anionic or anionizable groups that may be mentioned are those containing one or more carboxylate, sulfonate, sulfate, phosphate, phosphonate, etc. functions.
Mention may be made in particular of those of formula
—[—CH2—CH(R)—O]x—(CH2)y—COOH
or
—[—CH2—CH(R)—O]x—(CH2)y—COOM
in which:
Mention may be made most particularly of the carboxyl groups —COO−Na+ linked directly to a carbon atom of the sugar skeleton, carboxymethyl (sodium salt) —CH2—COO−Na+ linked to a carbon atom of the sugar skeleton via an —O— bond.
Among the nonionic groups that may be mentioned are those of formula:
•—[—CH2—CH(R)—O]x—R1
in which:
Mention may be made most particularly of the following groups:
The hexose units (identical or different) of the main chain of the native skeleton may be D-glucose, D- or L-galactose, D-mannose, D- or L-fucose, L-rhamnose, etc. units.
The neutral or anionic pentose and/or hexose units (identical or different) of the branches of the native skeleton may be D-xylose, L- or D-arabinose, D-glucose, D- or L-galactose, D-mannose, D- or L-fucose, L-rhamnose, etc., D-glucuronic acid, D-galacturonic acid, D-mannuronic acid, etc. units.
Examples of native skeletons that may be mentioned include galactomannans, galactoglucomannans, xyloglucans, xanthan gums, scleroglucans, succinoglycans, rhamsans, welan gums, etc.
The native skeleton is preferably a galactomannan. Galactomannans are macromolecules comprising a main chain of D-mannopyranose units linked in position β(1-4) substituted with D-galactopyranose units in position α(1-6). Among these, mention may be made of guar gum, carob gum and tara gum.
The native skeleton is most preferably a guar gum. Guar gums have a mannose/galactose ratio of 2.
The anionic polysaccharides according to the invention may be obtained in a known manner.
Most of them are commercial products.
Examples of anionic polysaccharides according to the invention that may be mentioned include:
A second subject of the invention consists of a process for caring for articles made of textile fibers, by treating these articles with a composition, in aqueous or wet medium, comprising at least one anionic polysaccharide according to the invention.
A third subject of the invention consists in using, in a composition for treating articles made of textile fibers in an aqueous or wet medium, of at least one anionic polysaccharide according to the invention, as an agent for caring for textile fibers.
The composition and the working (or treatment) conditions may be in numerous forms.
Said composition may be
Thus, the composition of the invention may be:
The composition of the invention is particularly suitable for fabric care, especially for cotton-based fabrics, in particular fabrics containing at least 35% cotton. It is most particularly suitable for caring for colored fabrics.
The anionic polysaccharides according to the invention are soluble under the working conditions in aqueous or wet medium of said composition.
Said anionic polysaccharides are considered as soluble when more than 50% and preferably more than 70% of their weight are soluble in the working aqueous or wet medium of the composition of the invention, i.e. especially under the temperature and pH conditions of said medium.
The working pH of the composition of the invention may range from about 2 to about 12, depending on the desired use.
When it is:
The amount of anionic polysaccharide present in the care composition according to the invention may range from 0.05% to 10% as dry weight relative to the dry weight of said composition, depending on the desired application.
Thus, said anionic polysaccharide (AP) may be used as follows:
Other constituents may be present, along with the anionic polysaccharide, in the care composition according to the invention. Said composition may contain at least one surfactant and/or one detergent additive and/or rinsing additive and/or softening additive for articles made of textile fibers and/or one solid support (especially a textile support) for said anionic polysaccharide.
The nature of these constituents depends on the desired use of said composition.
Thus, when it is a detergent formulation, for washing fabrics, it generally comprises:
The detergent formulation may comprise surfactants in an amount corresponding to about 3% to 40% by weight relative to the detergent formulation, these surfactants being such as
Anionic Surfactants
The detergent adjuvants (“builders”) for improving the surfactant properties may be used in amounts corresponding to about 5-50% and preferably to about 5-30% by weight for the liquid detergent formulations or to about 10-80% and preferably 15-50% by weight for the powder detergent formulations, these detergent adjuvants being such as:
Mineral Detergent Adjuvants
The detergent formulation may also comprise at least one oxygen-releasing bleaching agent comprising a percompound, preferably a persalt.
Said bleaching agent may be present in an amount corresponding to about 1% to 30% and preferably from 4% to 20% by weight relative to the detergent formulation.
As examples of percompounds which may be used as bleaching agents, mention should be made in particular of perborates such as sodium perborate monohydrate or tetrahydrate; peroxygenated compounds such as sodium carbonate peroxyhydrate, pyrophosphate peroxyhydrate, urea peroxyhydrate, sodium peroxide and sodium persulfate.
The preferred bleaching agents are sodium perborate monohydrate or tetrahydrate and/or sodium carbonate peroxyhydrate.
Said agents are generally combined with a bleaching activator which generates, in situ in the washing medium, a peroxycarboxylic acid in an amount corresponding to about 0.1% to 12% and preferably from 0.5% to 8% by weight relative to the detergent formulation. Among these activators, mention may be made of tetraacetylethylenediamine, tetraacetyl-methylenediamine, tetraacetylglycoluryl, sodium p-acetoxybenzenesulfonate, pentaacetylglucose and octaacetyllactose.
Mention may also be made of non-oxygenated bleaching agents, which act by photoactivation in the presence of oxygen, these being agents such as sulfonated aluminum and/or zinc phthalocyanins.
The detergent formulation may also comprise soil-release agents, anti-redeposition agents, chelating agents, dispersants, fluorescers, foam suppressants, softeners, enzymes and various other additives.
Soil-release Agents
These may be used in amounts of about 0.01-10%, preferably about 0.1-5% and more preferably about 0.2-3% by weight.
Mention may be made more particularly of agents such as:
These may be used in amounts generally of about 0.01-10% by weight for a powder detergent formulation of about 0.01-5% by weight for a liquid detergent formulation.
Mention may be made in particular of agents such as:
Agents for chelating iron and magnesium may be present in amounts of about 0.1-10% and preferably of about 0.1-3% by weight.
Mention may be made, inter alia, of:
These may be present in an amount of about 0.1-7% by weight, to control the calcium and magnesium hardness, these being agents such as:
These may be present in an amount of about 0.05-1.2% by weight, these being agents such as: stilbene, pyrazoline, coumarin, fumaric acid, cinnamic acid, azole, methinecyanin, thiophene, etc. derivatives (“The production and application of fluorescent brightening agents”—M. Zahradnik, published by John Wiley & Sons, New York, 1982).
Foam Suppressants
These may be present in amounts which may be up to 5% by weight, these being agents such as:
These may be present in amounts of about 0.5-10% by weight, these being agents such as clays.
Enzymes
These may be present in an amount which may be up to 5 mg by weight and preferably of about 0.05-3 mg of active enzyme/g of detergent formulation, these being enzymes such as:
Mention may be made, inter alia, of:
The detergent formulation may be used, in particular in a washing machine, in a proportion of from 0.5 g/l to 20 g/l and preferably from 2 g/l to 10 g/l to carry out washing operations at a temperature from about 25 to 90° C.
A second embodiment of the care composition of the invention consists of an aqueous liquid formulation for rinsing and/or softening fabrics.
It may be used in a proportion of from 0.2 to 10 g/l and preferably from 2 to 10 g/l.
Along with the anionic polysaccharide, there may be present other constituents of the type such as:
A third embodiment of the care composition of the invention consists of an additive for drying fabrics in a suitable tumble dryer.
Said additive comprises a flexible solid support consisting, for example, of a strip of woven or nonwoven textile or a sheet of cellulose, impregnated with said anionic polysaccharide; said additive is introduced at the time of tumble-drying into the wet fabrics to be dried at a temperature from about 50 to 80° C. for 10 to 60 minutes.
Said additive may also comprise cationic softeners (up to 99%) and color-fast agents (up to 80%), such as those mentioned above.
A fourth embodiment of the care composition of the invention consists of an ironing formulation which may be sprayed directly onto the dry fabrics before ironing.
Said formulation may also contain silicone-based polymers (from 0.2% to 5%), nonionic surfactants (from 0.5% to 5%) or anionic surfactants (from 0.5% to 5%), fragrances (0.1% to 3%) or cellulose derivatives (0.1% to 3%), for instance starch; spraying said formulation onto the fabrics makes it easier to iron them and limits the creasing of the fabrics when they are worn.
A fifth embodiment of the care composition of the invention consists of a prespotter which is in the form of an aqueous solution or dispersion or a solid (stick).
Along with the anionic polysaccharide, there may be present other constituents of the type such as:
The examples that follow are given for illustrative purposes.
The anionic polysaccharide used in the examples below is a carboxymethyl guar with a degree of substitution of 1.6 and a weight-average molar mass of 1 400 000, determined as follows by size exclusion chromatography.
The measurement is performed in water at pH 9-10 containing 0.1 M LiCl and 2/10000 of NaN3. The characteristics of the machine are as follows:
The injected solution (200 μl) contains about 0.5% by weight of anionic polysaccharide. The weight-average molecular mass is established directly without calibration using the light scattering values extrapolated to zero angle; these values are proportional to CxMx(dn/dc)2.
Detergent Formulation
A washing operation is carried out in a Tergotometer laboratory machine which is well known in the profession to detergent composition formulators. The machine simulates the mechanical and thermal effects of pulsating-type American washing machines, but, by virtue of the presence of 6 washing drums, it makes it possible to carry out simultaneous series of tests with an appreciable saving in time.
25×25 cm test pieces are cut from unfinished cotton.
The cotton test pieces are first ironed so that they all have the same level of creasing before washing.
They are then washed using the above detergent formulation containing the anionic polysaccharide and rinsed once, under the following conditions:
The test pieces are then creased under a 3 kg press for 20 seconds, after which they are dried vertically overnight.
The same operation is carried out using the same detergent formulation, but free of the anionic polysaccharide.
A digital color photograph is then taken of the dry test pieces, which is then converted into 256 gray scale levels (gray scale from 0 to 255).
The number of pixels corresponding to each gray scale level are counted.
For each histogram obtained, the standard deviation σ of the distribution of the gray scale level is measured.
The performance value is given by the equation
−Δσ=σ2−σ1
The performance values obtained are as follows:
These positive values of −Δσ are representative of a crease-resistance property provided by the detergent formulation comprising the anionic polysaccharide according to the invention.
Rinsing/Softening Formulation
Measurement of the Protection of Colors
Principle
This consists in forming, under defined conditions, 10 washes of a sample of several colored cotton fabrics. The color protection efficacy is tested in an automatic washing machine. The actual assessment is performed by a reflectance measurement. The fabrics are examined before and after 10 washes. The variation in color thus recorded (ΔE*) constitutes the loss of color on each type of fabric.
Apparatus-reagents
The colors are measured on a LUCI100 reflectometer:
The measuring system used is the CIE [International Commission on Illumination]—L* a* b* (DIN6174, CIE-LAB 1976).
It is made up as follows:
Each sample of fabric is measured at 5 different points (one at the center and one in each corner) and the average of the components L*, a* and b* is calculated.
Exploiting the Results:
The reflectometer is equipped with software that indirectly calculates the ΔE* from the data previously recorded. This value corresponds to the color variation recorded on the fabric after washing and is expressed as follows:
ΔL*=L*after washing−L*before washing
Δa*=a*after washing−a*before washing
Δb*=b*after washing−b*before washing
The loss of color for each fabric is then given by the follow expression:
ΔE1=√{square root over ((ΔL1)2+(Δa1)+(Δb1))}2
The performance quality of the polysaccharide relative to the reference is measured as the difference in ΔE* between the formulae without and with polysaccharide.
The cumulative loss of color is calculated as the sum of the losses of color of the colored fabrics. A detergent formulation (F) is prepared by adding 1 part of anionic polysaccharide to 100 parts of composition (C) below (expressed in parts by weight):
This formulation (F) and the composition without anionic polysaccharide (C) are tested as described above.
The results obtained are as follows:
These results show that the presence of anionic polysaccharide in the formulation (F) allows the protection of the colors to be improved substantially.
| Number | Date | Country | Kind |
|---|---|---|---|
| 00/13334 | Oct 2000 | FR | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10399652 | Apr 2003 | US |
| Child | 11787089 | Apr 2007 | US |
