Abstract: The invention relates to a method of treating a fabric. It particularly relates to a method of treating a fabric with a rinse product that reduce soil pickup and further ensures that the fabric is cleaner after the subsequent wash. It is thus, an object of the present invention to provide a method of treating a fabric to render the fabrics relatively more hydrophobic and especially to provide a method of treating a fabric during the rinse stage of the fabric cleaning process that reduces subsequent soiling of the fabric during use by the consumer. It has been found that contacting the fabric with a neutral aqueous solution, comprising a water- soluble zinc compound, a deposition aid selected from the group consisting of an amine compound or an amino acid and a soap before drying said fabric, provides the soil repellence to the fabric.
FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
FABRIC TREATMENT
HINDUSTAN UNILEVER LIMITED, a company incorporated under
the Indian Companies Act, 1913 and having its registered office
at 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India
The following specification particularly describes the invention and the manner in which it is to be performed.
TECHNICAL FIELD
The invention relates to a method of treating a fabric. It particularly relates to a method of treating a fabric with a rinse product that reduce soil pickup and further ensures that the fabric is cleaner after the subsequent wash.
BACKGROUND AND PRIOR ART
Fabrics have traditionally been cleaned using detergent formulations. Detergent formulations generally comprise surfactants and builders. Surfactants are believed to work by reducing the surface tension of water thereby ensuring preferential partitioning of the soil from the surface of the fabric into the wash water. Builders are believed to act by reducing the hardness of water, thereby ensuring efficient utilization of the surfactants. Various other benefit agents have been included in detergent formulations e.g. perfumes, optical brighteners, electrolytes, free flow agents, soil release polymers (SRP), anti-redeposition agents (ARD), enzymes, bleaches, colourants and preservatives. Of the above, SRP and ARD agents are added to detergent formulation to enhance cleaning by acting on the soil.
Soil redeposition is a phenomenon that reduces the effective cleaning as compared to what surfactants can theoretically provide. Soil ledeposition is a long standing problem that detergent formulators have long fought to solve. Redeposition is defined as partitioning of soil removed from dirty clothes back on to both dirty/clean clothes during the washing process. This problem is illustrated by showing the gradual greying of a fresh white garment that has never been worn or used but only goes through the wash load. This shows that one of the primary reasons for whiteness loss or greying is due to redeposition of son. Typically, the whiteness loss due to redeposition is not evident in a single wash cycle but manifests itself gradually after multiple cycles. Some examples of common Anti redeposition polymers are sodium carboxy metyhl cellulose (SCMC), Sokalan CP5 or CP7, poly aspartic acid, Alcosperse and Narlex H1200
SRP agents act by mechanisms which makes the soil easier to release from the surface of the fabric. Several agents have been used to give soil release benefits: For example, starches, modified starches, carboxymethyl celluslose, polyethylene glycols, copolymers of maleic anhydride, and anionic surfactants provide improved soil release when sprayed or padded on to polyester or polyamide fabrics prior to soiling. Also, acrylate based copolymers have been successfully deposited on fabric from acidic rinses or rinses containing relatively high concentrations of polyvalent metal ions or water-soluble amine salts to give temporary soil release finishes. Fluorinated soil release agents can also be applied in a rinse mode. Polyester based co-poly(ethylene terepthalate)(polyoxyethylene terepthalate) (PET-POET soil release agents)have been particularly used for polyester fabrics These polymers were commercialized under trade names of Permalose, Cirrasol, PTG, Cirrasol PTN and Milease T.
The above agents are generally included in detergent formulations which are added in the wash cycle of the cleaning process. These cleaning formulations do not help much in reducing subsequent post-wash soiling of the fabrics. The present inventors have determined during the course of their extensive research in this area that one of the main ways in which soiling of fabrics can be kept more clean is by ensuring that soil pickup by the fabric post the wash is minimized. The present inventors then invented a heretofore not known step of treating the fabric during the rinse stage with a zinc compound that is able to give the above benefits. Without wishing to be bound by theory, the inventors believe that the present invention renders the surface of the fabric more hydrophobic thereby ensuring soil repellency benefits to the consumer fabrics. To the knowledge of the inventors, some papers have been published which describe methods of making substrates more hydrophobic.
Fabrics have traditionally been cleaned using detergent formulations. Detergent formulations generally comprise surfactants and builders. Surfactants are believed to work by reducing the surface tension of water thereby ensuring preferential partitioning of the soil from the surface of the fabric into the wash water. Builders
are believed to act by reducing the hardness of water, thereby ensuring efficient utilization of the surfactants. Various other benefit agents have been included in detergent formulations e.g. perfumes, optical brighteners, electrolytes, free flow agents, soil release polymers (SRP), anti-redeposition agents (ARD), enzymes, bleaches, colourants and preservatives. Of the above, SRP and ARD agents are added to detergent formulation to enhance cleaning by acting on the soil.
Soil redeposition is a phenomenon that reduces the effective cleaning as compared to what surfactants can theoretically provide. Soil redeposition is a long standing problem that detergent formulators have long fought to solve. Redeposition is defined as partitioning of soil removed from dirty clothes back on to both dirty/clean clothes during the washing process. This problem is illustrated- by showing the gradual greying of a fresh white garment that has never been worn or used but only goes through the wash load. This shows that one of the primary reasons for whiteness loss or greying is due to redeposition of soil. Typically, the whiteness loss due to redeposition is not evident in a single wash cycle but manifests itself gradually after multiple cycles. Some examples of common Anti redeposition polymers are sodium carboxy metyhl cellulose (SCMC), Sokalan CP5 or CP7, poly aspartic acid, Alcosperse and Narlex H1200
SRP agents act by mechanisms which makes the soil easier to release from the surface of the fabric. Several agents have been used to give soil release benefits: For example, starches, modified starches, carboxymethyl celluslose, polyethylene glycols, copolymers of maleic anhydride, and anionic surfactants provide improved soil release when sprayed or padded on to polyester or polyamide fabrics prior to soiling. Also, acrylate based copolymers have been successfully deposited on fabric from acidic rinses or rinses containing relatively high concentrations of polyvalent metal ions or water-soluble amine salts to give temporary soil release finishes. Fluortnated soil release agents can also be applied in a rinse mode. Polyester based co-poly(ethylene terepthalate)(polyoxyethylene terepthalate) (PET-POET soil release agents)have been particularly used for polyester fabrics These polymers
were commercialized under trade names of Permalose, Cirrasol, PTG, Cirrasol PTN and Milease T.
The above agents are generally included in detergent formulations which are added in the wash cycle of the cleaning process. These cleaning formulations do not help much in reducing subsequent post-wash soiling of the fabrics. The present inventors have determined during the course of their extensive research in this area that one of the main ways in which soiling of fabrics can be kept more clean is by ensuring that soil pickup by the fabric post the wash is minimized. The present inventors then invented a heretofore not known step of treating the fabric during the rinse stage with a zinc compound that is able to give the above benefits. Without wishing to be bound by theory, the inventors believe that the present invention renders the surface of the fabric more hydrophobic thereby ensuring soil repellency benefits to the consumer fabrics. To the knowledge of the inventors, some papers have been published which describe methods of making substrates more hydrophobic.
Tang et al. in Colloids and Surfaces A: Physicochem. Eng. Aspects 296 (2007) 92 -96 describe a process for preparing hydrophobic zinc oxide uniform nanorods via a one-step process through precipitation transformation reaction in aqueous solution of zinc sulphate, sodium carbonate and sodium hydroxide with sodium oleate.
Badre et al. in Nanotechnology 18 (2007) 365705 (4pp) describe preparation of superhydrophobic zinc oxide nanowire array films starting with zinc chloride by using an electrochemical method followed by surface modification with stearic acid.
The present inventors have determined that the process described by the above cited prior art are not suitable for everyday application in the homes for treating consumer fabrics in terms of meeting the desired technical efficacy, safety and convenience to the consumer and cost.
It is thus, one of the objects of the present invention to provide a method of treating a fabric to render the fabrics relatively more hydrophobic.
Another object of the present invention is to provide a method of treating a fabric during the rinse stage of the fabric cleaning process that reduces subsequent soiling of the fabric during use by the consumer.
Tang et al. in Colloids and Surfaces A: Physicochem. Eng. Aspects 296 (2007) 92 -96 describe a process for preparing hydrophobic zinc oxide uniform nanorods via a one-step process through precipitation transformation reaction in aqueous solution of zinc sulphate, sodium carbonate and sodium hydroxide with sodium oleate.
Badre et al. in Nanotechnology 18 (2007) 365705 (4pp) describe preparation of superhydrophobic zinc oxide nanowire array films starting with zinc chloride by using an electrochemical method followed by surface modification with stearic acid.
The present inventors have determined that the process described by the above cited prior art are not suitable for everyday application in the homes for treating consumer fabrics in terms of meeting the desired technical efficacy, safety and convenience to the consumer and cost.
It is thus, one of the objects of the present invention to provide a method of treating a fabric to render the fabrics relatively more hydrophobic.
Another object of the present invention is to provide a method of treating a fabric during the rinse stage of the fabric cleaning process that reduces subsequent soiling of the fabric during use by the consumer.
SUMMARY OF THE INVENTION
The present invention provides for a method for treating a fabric comprising the steps of:
(a) contacting the fabric with an aqueous solution, at a pH in the range of 7 to 11, comprising (i) a water- soluble zinc compound, (ii) a deposition aid selected
from the group consisting of an amine compound or an amino acid and (iii) a soap and (b) drying said fabric.
According another aspect of the present invention there is provided a fabric
treatment composition comprising
(i) 20 to 90 % water soluble zinc compound;
(ii) 5 to 50 % a deposition aid selected from the group consisting of an amine
compound or an amino acid; and
(iii) 5 to 50% soap.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for method that involves adding a set of compounds to the water during the rinse stage of the washing process. Thus the water along with the compounds dissolved/dispersed in it forms the treatment media. The set of compounds are:
(i) a water- soluble zinc compound
(ii) a deposition aid selected from the group consisting of an amine compound or an amino acid and
(iii) a soap
The pH of the aqueous solution is in the range of 7 to 11. It is preferred that the pH of the aqueous solution is in the range of 8 to 11. This pH may be the natural pH of the treatment media when it contains the essential ingredients of the media. Else, treatment media may comprise an alkaline compound. Preferred alkaline compounds are alkali metal carbonate or hydroxide. Most preferred alkaline compounds are sodium carbonate or sodium hydroxide. The alkaline compound is preferably present in 0.01 to 0.5%, more preferably in 0.05 to 0.2% by weight of the treatment media.
The step of treating the fabric with the above set of compounds is preferably carried out for a time period of about 15 minutes to about 90 minutes, preferably from 20 minutes to an hour. This treatment step could be with the fabric soaked in the treatment media with no agitation or the treatment media could be agitated. The term "water soluble" as used herein refers to a substance having solubility of greater than 0.1 g per 100 g of water at a temperature of 25°C.
The preferred water soluble zinc compounds for use in the present invention are zinc chloride, sulphate, nitrate or acetate, of which zinc nitrate is preferred. The zinc compound is preferably present in 0.01 to 1%, more preferably in 0.05 to 0.5% by weight of the treatment media.
The deposition aid is either an amine compound or an amino acid. Suitable amine compounds are methanol amine, diethanol amine or mono ethanol amine; triethanol amine being more preferred. Suitable amino acids are alanine, derivatives of alanine like phenyl alanine, 3,4-dihydroxy-L-phenylalanine or histidine. The deposition aid is preferably present in 0.01% to 0.5%, more preferably from 0.05% to 0.3% by weight of the treatment media.
The treatment media also comprises soap. Soap is a salt of a fatty acid. Preferred soaps are C8-C24 soap, preferably C10-C20 soap, and more preferably C12-C18 soap. The soap may or may not have one or more carbon-carbon double bond or triple bond. The iodine value of the soap, which is indicative of degree of unsaturation, is preferably less than 20, more preferably less than 10, and most preferably less than 5. Saturated soap having no carbon-carbon double bond or triple bond is particularly preferred. The soap may be water soluble or water insoluble. According to a preferred aspect, the soap is water soluble. Non-limiting examples of water soluble soaps that can be used according to the present invention include sodium laurate, sodium caprylate, and sodium myristate. The treatment media preferably comprises at least 0.01 to 0.5%, more preferably 0.05 to 0.3% soap by weight of the treatment media.
The method of the invention is carried out at a pH of the treatment media in the range of 7 to 11, more preferably between 8 and 11 and most preferably between 8 and 9.
The fabric treatment method of the invention may be carried out without any heating or cooling i.e. at normal room temperature e.g. from 15 to 40 °C.
The term "liquor to cloth ratio" or L/C ratio as used herein means the ratio of mass of the treatment media that is in contact with the fabric to the mass of the fabric. It is preferred that the liquor to cloth ratio in the treatment step is preferably from 2 to 100, more preferably from 5 to 50, most preferably from 5 to 20
After the treatment step, the fabrics may be further rinsed although no further rinse step is essential for obtaining the benefits of the invention. After the treatment, the fabrics may be optionally squeezed before drying, although this is not essential. The fabrics are then dried. The fabrics may be air dried, sun dried or dried in a drying machine. It is preferred that the fabrics after drying are ironed.
The method of the present invention for treatment of fabric may be carried out in the rinse stage after the fabrics are hand washed or the rinsing may be carried out in a machine.
The method of the invention has the additional advantage that the treated fabric has antibacterial property. Thus, the bacteria that get transferred to the fabric from the atmosphere during storage and use, are either killed or are not allowed to grow. One of the advantages of the anti-bacterial property of the treated fabric is that it affords malodour control to the fabric. It is well known that zinc compounds give anti-bacterial property to treated substrates. This is traditionally done by coating substrates with zinc oxide. The present invention provides higher anti-bacterial efficacy as compared to prior art method of treating fabric with zinc oxide.
According another aspect of the present invention there is provided a fabric
treatment composition comprising
(i) 20 to 90 % water soluble zinc compound;
(ii) 5 to 50 % a deposition aid selected from the group consisting of an amine
compound or an amino acid; and (iii) 5 to 50% soap.
The water soluble zinc compound is preferably present in 30- 80%, more preferably in 55 to 70% by weight of the fabric treatment composition. The deposition aid is present in 5-40% more preferably 10 - 25% by weight of the fabric treatment composition. The soap is preferably present in 5 - 40%, more preferably 15- 25% by weight of the fabric treatment composition.
The composition preferably comprises an alkaline compound selected from alkali metal carbonate or hydroxide in the aqueous solution. The alkaline compound is preferably present in 5 to 30 % by weight of the fabric treatment composition.
According to yet another aspect of the present invention there is provided use of a composition of the invention for treating a fabric to make it hydrophobic to the extent of having a contact angle higher than 90° with water. The contact angle is preferably between 90 and 180° more preferably between 120° and 180°. The contact angle is measured using a tensile drop method immediately after droplet addition.
The composition of the present invention is preferably in the solid form. Suitable solid forms are powders or granules.
Description of the figure
Figure 1 shows comparative data from example 18 (example according to the invention, indicated as E-18) and example 19 (comparative example, indicated as E-19). The graph of Figure 1 shows the effect of cleaning (by means of reflectance of light at 460 nm, called R460 values) during 5 soil-wash cycles. AW indicates the
value after wash and BW indicates the value before wash; and 1, 2, 3, 4, and 5 refer to the 1st, 2nd, 3rd, 4th and 5th wash cycle respectively.
EXAMPLES
Fabrics were treated by any one of the treatments A, B or c as described below:
Treatment Protocols
Treatment A: (as per invention)
To 1 litre of deionised water 1 g of sodium laurate, 0.8 9 of sodium carbonate was
added and dissolved completely. To this 1,1 g of triethanolamine was added and
finally 2.97 g of Zn(N03)2.6H20 were added.
40 fabrics each of 1 g (100 cm2) were soaked in 1 litre of the above solution for 1
hour. After soaking the fabrics were rinsed once in 1 litre of deionised water and
dried in air and ironed.
Treatment B: fas per methods suggested in the past)
To 1 litre of deionised water, 1 g of sodium laurate, 08 9 of sodium carbonate was
added and dissolved completely. To this 2.97g of Z(NO3)2 was added and
dissolved
40 fabrics each of 1g (100 cm2) were soaked in 1 litre of the above said composition for 1 hour. After soaking the fabrics were rinsed once in 1 litre of deionised water and dried in air and ironed.
Treatment C: No treatment
40 fabrics each of 1g (100 cm2) were soaked in 1 litre of the deionised water for 1 hour After soaking the fabrics were rinsed once in 4 litre of deionised water and dried in air and ironed.
Treatment D: (Treatment as per invention)
To 1 litre of deionised water 1 g of sodium laurate, 0,8 g of sodium carbonate was added and dissolved completely. To this 0.5 g of dihydroxy-L-phenylalanine was added and finally 2.97 g of Zn(N03)2.6H20 were added.
40 fabrics each of 1 g (100 cm2) were soaked in 1 litre of the above solution for 1 hour. After soaking the fabrics were rinsed once in 1 litre of deionised water and dried in air and ironed.
Treatment E: (Treatment as per invention)
To 1 litre of deionised water 1 g of sodium laurate, 0.8 g of sodium carbonate was added and dissolved completely. To this 0.5 g of Histidine was added and finally 2.97 g of Zn(N03)2.6H20 were added.
40 fabrics each of 1 g (100 cm2) were soaked in 1 litre of the above solution for 1 hour. After soaking the fabrics were rinsed once in 1 litre of deionised water and dried in air and ironed.
Treatment F: (Treatment as per invention)
To 1 litre of 48 FH water (Ca2+:Mg2+) 1 g of sodium laurate, 0.8 g of sodium carbonate was added and dissolved completely. To this 1.1 g of triethanolamine was added and finally 2.97 g of Zn(N03)2-6H20 were added.
40 fabrics each of 1 g (100 cm2) were soaked in 1 litre of the above solution for 1 hour. After soaking the fabrics were rinsed once in 1 litre of 48 FH water and dried in air and ironed.
Soiling Protocol
C-Soot Soiling:
In 1 litre of deionised water 15 mg of Carbon Soot (Cabot India) and 50 mg of sodium linear alkyl benzene sulphonate (NaLAS) were taken. This dispersion was sonicated for 2 hours in a bath sonicator.
To 80 ml of the above dispersion, 10 fabrics (1 g each) were dipped and stirred for 5 minutes. The soiled fabrics were line dried in air overnight.
Carbon soot Soiling Protocol -2
In 1 litre of 48 FH water (Ca:Mg = 2:1 molar ratio), 150 mg of Carbon Soot (Cabot
India) was taken. This dispersion was sonicated for 2 hours in a bath sonicator.
To 100 ml of the above dispersion, 9 fabrics (1 g each) were dipped and stirred for 2 minutes. The soiled fabrics were line dried in air overnight.
Red Mud Soiling:
To 1 litre of deionised water 1.5 g of red mud (ex HURC, sieved, particle size <150
µ) was added and sonicated in a bath sonicator for 2 hours.
In 100 ml of the above slurry, 10 fabrics (of 1g each) were soaked for 2 minutes. The soiled fabrics were line dried in air overnight.
Dirty Motor Oil Soiling:
2 ml of concentrated Dirty Motor Oil (i.e. partially oxidized motor oil collected from an
automobile after running 5000 km) was diluted in 50ml of triolein. 200 µl of the
above diluted soil was then put on a 1 g fabric using a micropipette and soiled
fabrics were dried overnight.
Composite Soil Soiling:
50 ml_ triolein and 4 mg iron oxide and 4 mg carbon soot were mixed and sonicated
using a bath sonicator for two and half hours. 300 µl of this soil was used on 1 g of
fabric using a micropipette and soiled fabrics were dried overnight.
Diesel Soil Box soiling
The fabrics were hung in a Diesel Soil Box chamber using a hanger. It was soiled by applying a load of 4500W for 3 hours. The diesel exhaust fumes mainly comprise of carbon soot particulates along with a small amount of unburnt mineral oil suspended in air and carbon dioxide.
Wash Protocol
Typical wash protocol involved soaking 20 g of fabrics in 1 litre of deionised water containing 3 g of Surf Excel (ex. Hindustan Unilever Limited) for 15 minutes. They were washed in a Tergotometer at 90 rpm for 30 minutes at ambient temperature. After washing, the fabrics were rinsed three times, each with 450 ml of water for 2 minutes in Tergotometer at 90 rpm and dried in air.
Wash Protocol - 2
Typical wash protocol involved soaking 20 g of fabrics in 1 litre of 48 FH (Ca2+: Mg2+ = 2:1 molar ratio) water containing 3 g of Surf Excel (ex. Hindustan Unilever Limited) for 15 minutes. They were washed in a Tergotometer at 90 rpm for 30 minutes at ambient temperature. After washing, the fabrics were rinsed three times, each with 450 ml of 48 FH water for 2 minutes in Tergotometer at 90 rpm and dried in air.
Reflectance measurement
Reflectance of all fabrics before and after washing were measured using Macbeth Reflectometer at wavelength 460 nm, UV excluded, SCI using a large aperture. Experiments 1 to 6: Effect of treatment method of the invention on soil pickup. Experiments were conducted with different fabrics (having initial reflectance of 85) were treated as per Treatment method A, B, or C. The treated fabric were soiled with the red mud soiling method, as described above. The reflectance of the fabrics after soiling was measured and the values are summarized in Table - 1.
Table -1
The data in Table - 1 indicates that the fabrics treated as per the method of the invention (Examples 1 and 4) tended to pick up less soil as compared to fabrics treated as per methods suggested in the past and as compared to untreated fabrics.
Experiments 7 to 17: Effect of treatment method of the invention on cleaning of
fabrics.
Experiments were conducted with different fabrics (having initial reflectance of 85)
which were treated with any one of the Treatment methods A to E. The treated
fabrics were soiled with different soiling methods, as described above. The
reflectance of the fabrics after soiling and thereafter after washing was measured
and the values are summarized in Table - 2.
Table - 2
The data in Table - 2 indicates that the fabrics treated as per the method of the invention (Examples 7, 10-12, 14, 16) generally tended to pick up less soil as compared to fabrics treated as per methods suggested in the past and as compared to untreated fabrics for the same type of fabric and same soiling protocol. Further
the fabrics treated as per the method of the invention, after soiling also tended to be cleaner when washed using a standard washing protocol as compared to untreated fabrics or fabrics treated as per methods suggested in the past.
Examples 18 and 19: Effect of the method of the invention on the cleaning of fabrics after several treatment -soiling-washing cycles.
Fabrics were taken through several cycles, each cycle consisting of (i) treatment as per Treatment method A or Treatment C (ii) soiling of fabrics using Diesel soil box soiling protocol followed by (iii) the washing protocol. Example 18 was an experiment using cotton fabric which was treated as per Treatment A while Example 19 was an experiment using cotton fabric which was treated as per Treatment C. The data on the reflectance during the course of 5 cycles is given in Figure 1. The data in Figure 1 indicates that fabrics treated as per the invention (Example - 18) gives improved cleaning over several wash cycles.
Examples 20 to 23: Antibacterial efficacy
The antibacterial efficacy of substrates treated as per the invention was compared to antibacterial efficacy of substrates treated with a method of the prior art i.e. treatment with equivalent amount of zinc oxide.
A known antimicrobial assay was modified to enable study on treated fabrics. The known method is as follows:
Resazurin, a blue colored dye, undergoes reduction in the presence of viable bacteria to form a fluorescent pink colored dye resorufin which emits florescence at 590 nm. Measurement of resorufin either by spectrophotometry or fluorimetry after several hours of incubation indicates the activity of bacteria and hence antimicrobial activity of the compound used for the treatment.
The modified antibacterial assay was as follows:
Staphylococcus spp. bacteria (which is a fatty acid metabolising bacteria) was subcultured on CY agar plates at 37 °C. The metabolically active cells were collected which gave an optical density of 0.2 at 610 nm. This was further diluted
(1:10) in BHI Brain Heart Infusion) broth - Bacto 237500 media. The bacterial number at this concentration was determined to be 107 cells/ml. Four 1cm x 1cm fabric swatches (treated and untreated) were aseptically introduced into 24 well plate. About 1ml of the culture (diluted in BHI) and 0.5 µl of 1% resazurin was added in each well. The plates were incubated at 37°C. The wells were inspected for change in colour over 5 hrs. Colour was measured using a fluorimeter. The fluro scan was taken at 530EX/620EM. The data is presented in Table - 3.
Table - 3
The data in Table - 3 indicates that fabric treated as per the invention is far superior to untreated samples and also superior to fabric treated with conventional zinc oxide.
Experiments 24-29: Effect of treatment method of the invention on cleaning of
fabrics in hard water.
Experiments were conducted with different fabrics (having initial reflectance of 85)
which were treated with Treatment methods F (as per invention) or C (No
treatment).
The treated fabrics were soiled with methods as shown in Table-4 below. The reflectance of the fabrics after soiling and thereafter after washing was measured and the values are summarized in Table - 4.
Table - 4
The data in Table - 4 indicates that the fabrics treated as per the method of the invention (Examples 24, 26, 28) generally tended to pick up less soil as compared to untreated fabrics when treatment is carried out in hard water. Further the fabrics treated as per the method of the invention, after soiling also tended to be cleaner when washed in hard water as compared to untreated fabrics washed using the same protocol.
CLAIMS
1. A method for treating a fabric comprising the steps of:
a) contacting the fabric with an aqueous solution, at a pH in the range of 7 to 11, comprising (i) a water- soluble zinc compound, (ii) a deposition aid selected from the group consisting of an amine compound or an amino acid and (iii) a soap and
b) drying said fabric.
2. A method as claimed in claim 1 wherein the aqueous solution comprises
0.01 to 1% water soluble zinc compound.
. 3. A method as claimed in claim 1 or claim 2 wherein the water soluble zinc compound is a chloride, sulphate, nitrate or acetate of zinc.
4. A method as claimed in any one of the preceding claims wherein the aqueous solution comprises 0.01 to 0.5% deposition aid.
5. A method as claimed in any one of the preceding claims wherein the aqueous solution comprises 0.01 to 0.5% soap.
6. A method as claimed in any one of the preceding claims wherein said soap is water soluble.
7. A method as claimed in any one of the preceding claims wherein the desired pH is achieved by including an alkaline compound selected from alkali metal carbonate or hydroxide in the aqueous solution.
8. A method as claimed in any one of the preceding claims wherein the fabric is ironed subsequent to the step of drying.
9. A fabric treatment composition comprising
(i) 20 to 90 % water soluble zinc compound;
| # | Name | Date |
|---|---|---|
| 1 | 2442-MUM-2008 POWER OF ATTORNEY(24-11-2009).pdf | 2009-11-24 |
| 2 | 2442-MUM-2008 CORRESPONDENCE(24-11-2009).pdf | 2009-11-24 |
| 3 | abstract1.jpg | 2018-08-09 |
| 4 | 2442-MUM-2008-GENERAL POWER OF ATTORNEY(5-11-2009).pdf | 2018-08-09 |
| 5 | 2442-MUM-2008-FORM 5(5-11-2009).pdf | 2018-08-09 |
| 6 | 2442-mum-2008-form 3.pdf | 2018-08-09 |
| 7 | 2442-MUM-2008-FORM 3(8-8-2012).pdf | 2018-08-09 |
| 8 | 2442-MUM-2008-FORM 3(5-11-2009).pdf | 2018-08-09 |
| 9 | 2442-MUM-2008-FORM 3(4-8-2010).pdf | 2018-08-09 |
| 10 | 2442-MUM-2008-FORM 3(24-2-2010).pdf | 2018-08-09 |
| 11 | 2442-MUM-2008-FORM 3(15-2-2012).pdf | 2018-08-09 |
| 12 | 2442-mum-2008-description(provisional).pdf | 2018-08-09 |
| 12 | 2442-MUM-2008-FORM 3(15-2-2011).pdf | 2018-08-09 |
| 13 | 2442-MUM-2008-DRAWING(5-11-2009).pdf | 2018-08-09 |
| 13 | 2442-MUM-2008-FORM 3(12-8-2011).pdf | 2018-08-09 |
| 14 | 2442-mum-2008-form 2.pdf | 2018-08-09 |
| 14 | 2442-mum-2008-drawing.pdf | 2018-08-09 |
| 16 | 2442-mum-2008-form 2(title page).pdf | 2018-08-09 |
| 17 | 2442-MUM-2008-FORM 2(TITLE PAGE)-(5-11-2009).pdf | 2018-08-09 |
| 18 | 2442-mum-2008-form 2(5-11-2009).pdf | 2018-08-09 |
| 19 | 2442-MUM-2008-FORM 18(13-8-2012).pdf | 2018-08-09 |
| 20 | 2442-MUM-2008-FORM 13(7-2-2012).pdf | 2018-08-09 |
| 21 | 2442-MUM-2008-FORM 13(1-11-2011).pdf | 2018-08-09 |
| 22 | 2442-mum-2008-form 1.pdf | 2018-08-09 |
| 23 | 2442-MUM-2008-FER.pdf | 2018-08-09 |
| 24 | 2442-mum-2008-drawing.pdf | 2018-08-09 |
| 25 | 2442-MUM-2008-DRAWING(5-11-2009).pdf | 2018-08-09 |
| 26 | 2442-mum-2008-description(provisional).pdf | 2018-08-09 |
| 28 | 2442-MUM-2008-DESCRIPTION(COMPLETE)-(5-11-2009).pdf | 2018-08-09 |
| 29 | 2442-mum-2008-correspondence.pdf | 2018-08-09 |
| 30 | 2442-MUM-2008-CORRESPONDENCE(5-11-2009).pdf | 2018-08-09 |
| 31 | 2442-MUM-2008-CORRESPONDENCE(13-8-2012).pdf | 2018-08-09 |
| 33 | 2442-MUM-2008-CLAIMS(5-11-2009).pdf | 2018-08-09 |
| 35 | 2442-MUM-2008-ABSTRACT(5-11-2009).pdf | 2018-08-09 |
| 36 | 2442-MUM-2008-AbandonedLetter.pdf | 2018-08-09 |
| 37 | 2442-MUM-2008- AFR.pdf | 2022-05-30 |
| 1 | PatSeer_23-06-2017.pdf |