FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
AQUEOUS RINSE TREATMENT COMPOSITIONS
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.

FIELD OF INVENTION
The present invention relates to rinse treatment compositions. In particular, the invention relates to compositions that may be used to reduce residual surfactant from water that has been utilised for washing or rinsing fabrics.
The invention will be described hereinafter with reference to this application.
BACKGROUND AND RELATED ART
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.
In most developing and emerging countries, most people wash clothes in basins or buckets. The process of washing clothes in basins or buckets involves a soaking step, a washing step, and a rinsing step. In the soaking step, soiled clothes are soaked in a detergent solution. At this stage, people prefer to use high-foaming detergent compositions. In the washing step, people generally apply a direct application bar, such as NSD (Non-Soap Detergent) bar, to heavily soiled areas. The soiled areas are also cleaned using implements, such as a brush. In such cases, an appreciable amount of anionic surfactants remains on the surface of the fabrics. This phenomenon is also known in the art as "carry-over" of anionic surfactants. When such fabrics laden with anionic surfactants are rinsed, the surfactants cause a significant amount of foam in the rinse-liquor. In the rinsing step, the clothes are generally rinsed three to four times, each time using a bucket of clean water. The main reason for three to four rinses is that people often tend to rinse clothes till there is minimal foam, soapy feel, or turbidity in the rinse liquor. Part of the problem lies in the perception of the people.

Surfactant cleaning action is accompanied by foaming, and people attempt to remove the foam by repeated rinsing. The three to four buckets of water that gets used for rinsing is unfit for any secondary use, and is therefore, generally discarded.
The World Water Council and United Nations (UNO) have classified several countries of the world as water-stressed countries, i.e. countries that face acute water shortage. Large quantity of water is required for the industrial sector and the agricultural sector. While the demand for water keeps going up, the supply continues to be erratic, as most of it comes from seasonal rains; the timing, duration, and intensity of which is increasingly becoming unpredictable. Therefore water will become an increasingly scarce natural resource.
In this context, consumers will prefer to use products that would help them to reduce their consumption of water at home. Laundry is one of the biggest water-consuming chores, and as such, it has a huge environmental impact considering the amount of water that gets used worldwide for washing clothes. Most of this water is not recycled.
Therefore, there is a need for a product that can help reduce the consumption of water in laundry, especially while rinsing clothes, and thereby help conserve water.
Some attempts have been made in the past in this direction.
WO0121747A (Procter & Gamble) discloses a fabric rinse treatment composition that has a clarity value upon dilution of less than a 0.04 % by weight of a dimethyl bis(steroyl oxyethyl) ammonium chloride aqueous solution, and a suds reduction value of at least about 50%. The suds suppressing system is selected inter-aiia from silicone antifoam compounds, and quaternary ammonium compounds. This publication addresses the problem of clarity of the rinse water.

WO0198447A (Procter & Gamble) discloses a fabric rinse treatment composition containing an acid for depressing the pH of the rinse bath below about 6.5, a suds suppression system having an anti-foaming agent, a metal ion control agent, a crystal growth inhibitor, a dispersant polymer, and a detergent builder. Silicones have been described to be the most preferred anti-foaming agents.
EP 2179019 A2 (Byotrol PLC, 2010) discloses an anti-microbial composition which includes an antimicrobial agent with surfactant properties, particularly having higher surface tension, a siloxane selected from those having the formulae (H3C)[SiO(CH3)2]nSi(CH3)3, and {H3C)[SiO(CH3)H]nSi(CH3)3, and mixtures thereof, wherein n is from 1 to 24, the siloxane specifically having surface tension in the range of 20 mN/m to 30 mN/m and a polar solvent; wherein the ratio of the antimicrobial agent with surfactant properties to the siloxane is from about 100:1 to about 5:1. The composition preferably has an additional antimicrobial agent, such as a benzisothiozolinone.
The present inventors found that rinse treatment compositions generally have the following problems:
(i) turbid appearance;
(ii) comparatively lower stability, especially at elevated temperature;
(iii) phase separation, particularly, a floating oily layer; and,
(iv) comparatively poorer performance to provide an acceptable level of foam reduction.
We have determined that some or all of the problems of the prior art may be overcome or ameliorated by using selected silicones in particular rinse treatment compositions.

SUMMARY OF THE INVENTION
According to a first aspect, the present invention provides an aqueous rinse treatment composition having pH less than 7, the composition comprising:
(i) a cationic compound;
(ii) an amino functional polydimethylsiloxane;
(iii)a non-ionic surfactant;
(iv)an organic acid; and,
(v) a rheology modifier.
According to a second aspect the present invention provides a process for preparing an aqueous rinse treatment composition of the first aspect, where the process includes a step of adding the cationic compound, amino functional polydimethylsiloxane, non-ionic surfactant, the organic acid and the rheology modifier to water to form a mixture, and agitating the mixture to form the composition.
According to a third aspect, the invention provides a method of rinsing fabrics which includes a step of contacting the fabrics with an aqueous solution of the composition of the first aspect, where the fabrics have been previously contacted with a detergent composition.
According to a fourth aspect, the invention provides use of a composition of the first aspect for rinsing fabrics which have been cleaned with a detergent composition.
According to a fifth aspect, the invention provides a kit which includes an aqueous rinse treatment composition of the first aspect and a set of instructions on use of the composition.

The term "comprising" is meant not to be limiting to any subsequently stated elements but rather to encompass non-specified elements of major or minor functional importance. In other words the listed steps, elements or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above.
Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material ought to be understood as modified by the word "about".
It should be noted that in specifying any range of concentration or amount, any particular upper concentration can be associated with any particular lower concentration or amount.
The terms weight percent, percent by weight, % by weight, wt%, and the like are synonyms that refer to the concentration of a substance as the weight of that substance divided by the weight of the composition and multiplied by 100.
The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing "a compound" includes a mixture of two or more compounds. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.
The terms "fabric", "clothes" and "fabric article", as used herein, are intended to mean any article that is customarily cleaned in a conventional laundry process.

As such the term encompasses articles of clothing, linen, drapery, and clothing accessories. The term also encompasses other items made in whole or in part of fabric, such as tote bags, furniture covers, tarpaulins and the like. Further, the fabric may be made of natural fibres, synthetic fibres, or a combination thereof.
The invention will now be explained in detail.
DETAILED DESCRIPTION
In accordance with a first aspect, the invention provides an aqueous rinse treatment composition having pH less than 7, where the composition includes:
(i) a cationic compound;
(ii) an amino functional polydimethylsiloxane;
(iii) a non-ionic surfactant;
(iv)an organic acid; and,
(v) a rheology modifier.
The cationic compound:
The cationic compound is preferably present from 0.5 wt% to 10 wt% in the composition, more preferably 2 wt% to 8 wt%, and most preferably 0.5 wt% to 7.5 wt%. The cationic compound is preferably selected from Benzalkonium chloride, substituted Benzalkonium chlorides, di(C8-C12)dialkyl dimethyl ammonium chloride, N-(3-chloroallyl) hexaminium chlorides, benzethonium chloride, methylbenzethonium chloride, Cetylpyridinium chloride, or esterquats, and ethanol based quats. The cationic compound should be water-soluble and should be capable of complexing with anionic surfactants. Some cationic compounds, e.g. Benzalkonium chloride may also act a preservative. Suitable commercially available cationic compounds include BARQUAT™, MAQUAT™, VARIQUAT™, HYAMINE™ 1622 and , HYAMINE™ 10X, BARDAC™, DOWICIDE™, DOWICIL™, and CEPACOL™.

Benzalkonium chloride is the most preferred cationic compound, which is commercially available, generally as a 50 % aqueous solution. Without wishing to be bound by theory, it is believed that cationic compounds also help reduce foam in addition to complexing with anionic surfactants typically present in detergent compositions.
The amino functional polydimethylsiloxane:
Suitable amino functional polydimethylsiloxanes have been described in US2008275194 (assigned to Wacker Chemie AG), which is incorporated herein in its entirety by reference.
The composition includes 0.01 wt% to 5 wt% amino functional polydimethylsiloxanes. Preferred compositions include 0.1 wt% to 0.5 wt% amino functional polydimethylsiloxanes. More preferred compositions include 0.2 wt% to 0.4 wt% amino functional polydimethylsiloxanes.
It is further preferred that amine number of the amino functional polydimethylsiloxane is at least 0.6 mg/KOH per gram, more preferably from 0.6 to 2.0 mg/KOH per gram, and most preferably from 10 to 1.5 mg/KOH per gram.
It is preferred that the surface tension of the amino functional polydimethylsiloxane is about 20 mN/m to 30 mN/m, preferably 25 mN/m when measured at 20 °C. Without wishing to be bound by theory, it is believed that lower surface tension allows for better dispersion of the amino functional polydimethylsiloxane.
Non-ionic surfactants:
The aqueous rinse treatment compositions also include a non-ionic surfactant. Non-ionic surfactants are well known in the art. The non-ionic surfactant is preferably chosen to closely match the HLB value of the amino functional polydimethylsiloxane in the aqueous silicone emulsion.

It is preferred that HLB (Hydrophilic Lipophilic Balance) of the non-ionic surfactant is 80% to 120% of the HLB of the amino functional polydimethylsiloxane. The Hydrophilic-lipophilic balance of a surfactant is a measure of the degree to which it is hydrophilic or lipophilic. One skilled in the art would know what HLB is, and how that is measured. A mixture of non-ionic surfactants may also be used. It is believed that presence of non-ionic surfactant helps to reduce phase separation. The compositions include 0.01 wt% to 1 wt%, preferably 0.01 wt% to 0.5 wt%, and more preferably 0.01 wt% to 0.8 wt% non-ionic surfactant. Preferred non-ionic surfactants belong to the Trideceth range. Trideceth range of non-ionic surfactants includes Trideceth-2, Trideceth-3, Trideceth-4, Trideceth-5, Trideceth-6, Trideceth-7, Trideceth-8, Trideceth-9, Trideceth-10, Trideceth-11, Trideceth-12, Trideceth-15, Trideceth-18, Trideceth-20, Trideceth-21, and Trideceth-50. These are polyethylene glycol ethers of Tridecyl alcohol. They are also known as Polyoxyethylene Tridecylether. The number in the name indicates the average number of units of ethylene oxide in the molecule. Trideceth-3 and Trideceth-5 are particularly preferred. Trideceth surfactants are used in the formulations of a variety of skin care and hair care products.
In addition to the non-ionic surfactants listed above, preferred compositions may also include butyoxydiglycol. It is also known as Diethylene Glycol Butyl Ether. Its molecular structure is C4H9(OCH2CH2)2OH.
Organic acid:
The compositions also include an organic acid. A preferred acid may be selected from citric acid, succinic acid, polyacrylic acid, acetic acid, boric acid, maionic acid, adipic acid, fumaric acid, lactic add, glycolic acid, tartaric acid, tartronic acid, maleic acid. Without wishing to be bound by theory it is believed that the organic acid improves rheology of the emulsion. Citric acid and acetic acid are particularly preferred. The compositions include 0.5 wt% to 5 wt%, preferably 0.8 wt% to 4 wt%, and most preferably 1 wt% to 3 wt% organic acid. A mixture of acids may also be used.

While organic acids are preferred; mineral acids, such as Hydrochloric acid may also be used as an equivalent, albeit at comparatively lower percentages.
Rheology modifier:
The composition also includes a rheology modifier, further to any rheology
modifying action of the organic acid. Preferred rheology modifiers are salt of
carboxylic acids, more preferably an alkali metal salt of a carboxylic acid. The
most preferred salt is Sodium acetate.
Emulsion of the amino functional polydimethylsiloxane:
It is highly preferred that the amino functional polydimethylsiloxane is emulsified to form an emulsion, where the emulsion includes the non-ionic surfactant, at least some of the organic acid, and the rheology modifier. This emulsion may then be used to make the rinse-treatment compositions according to the invention. Preferred compositions have 0.1 wt% to 5 wt% of the emulsion, more preferably 0.2 wt% to 2 wt%, and most preferably 0.5 wt% to 1 wt% emulsion. The emulsion may contain 40 % to 80 % solids. Suitable silicone emulsions are available from Wacker Chemie AG. A preferred emulsion is Wacker UL 7722M1. When the composition includes this emulsion, at least some part of the organic acid is present in the emulsion. The rest may be included in the main composition.
The pH of the rinse treatment compositions:
The pH of 0.2 wt% solution of the aqueous rinse treatment composition in distilled water, when measured at 20 °C is less than 7, preferably from 1.5 to 6.5, most preferably from 1.5 to 4, and further more preferably 1.5 to 3. Without wishing to be bound by theory, it is believed that the acidic pH range helps reduce the foam. The pH may be achieved because the compositions include an acid.

Water:
The aqueous rinse treatment composition primarily contains water due to its low cost, easy availability, safety, ability to solubilise most of the ingredients, and low environmental impact.
The level of water in the composition is preferably at least 50 wt%, more preferably at least 60 wt%, further preferably 75 wt% to 95 wt% and most preferably 88 wt% to 92 wt%. The water may preferably be demineralised, and more preferably have pH around 6, such as 6.2. Mixtures of water and low molecular weight, (e.g., less than about 200 D), organic solvents, e.g., lower alcohols such as ethanol, propanol, isopropanol or butanol may also be used, but less preferably. Low molecular weight alcohols include monohydric, dihydric (such as glycols) trihydric (such as glycerol), and higher polyhydric alcohols.
Preferred ingredients:
Polydimethvlsiloxane and fumed silica:
It was observed by the present inventors that prior art compositions were:
(i) turbid in appearance;
(ii) had comparatively lower stability, especially at elevated temperature;
(iii) showed phase separation, particularly, a floating oily layer; and,
(iv) showed comparatively poor performance, especially in the ability to provide an acceptable level of foam reduction.
It was observed that such problems could be solved in preferred compositions. However, some preferred compositions had a tendency to foam when agitated. While this may not be regarded as a problem, we found that when polydimethylsiloxane and fumed silica were included in some preferred compositions, there was no foam. Therefore, it is preferred that the compositions also include a polydimethylsiloxane and fumed silica.

Perfume:
Preferred compositions include a perfume. In such a case, the rinse treatment compositions may deliver high-quality and long lasting perfume impact on clothes. As used herein the term "perfume" is used to indicate any odoriferous material that is subsequently released into the aqueous rinse solution and/or onto fabrics contacted therewith.
The perfume will most often be liquid at ambient temperatures. A wide variety of chemicals are known for perfume uses, including materials such as aldehydes, ketones, and esters. More commonly, naturally occurring plant and animal oils and exudates comprising complex mixtures of various chemical components are known for use as perfumes. The perfumes herein can be relatively simple in their compositions or can comprise highly sophisticated complex mixtures of natural and synthetic chemical components, all chosen to provide any desired odour. Typical perfumes can comprise, for example, woody/earthy bases containing exotic materials such as sandalwood, civet and patchouli oil. The perfumes can be of a light floral fragrance, e. g. rose extract, violet extract, and lilac. The perfumes can also be formulated to provide desirable fruity odours, e. g. lime, lemon, and orange. Likewise, the perfumes may be selected for an aromatherapy effect, such as providing a relaxing or invigorating mood. As such, any material that exudes a pleasant or otherwise desirable odour can be used as a perfume in the compositions of the present invention. Likewise, the perfumes may be of the encapsulated type, such as, shear sensitive encapsulates which deposit on fabrics during the rinse process and are capable of undergoing rupture, later, to release the perfume.
Preservatives:
While certain cationic compounds, e.g. Benzalkonium chloride may also act as a
preservative, the aqueous rinse-aid compositions may also include a further
preservative.

Known antimicrobial preservatives can be added to the composition of the present invention. Contamination by certain microorganisms with microbial growth can result in an unsightly and/or malodorous solution.
Microbial growth in solutions is generally objectionable; it is preferable to include an antimicrobial preservative, which is effective for inhibiting and/or regulating microbial growth in order to increase storage stability of the composition. Preferred water-soluble preservatives include organic sulfur compounds, halogenated compounds, cyclic organic nitrogen compounds, low molecular weight aldehydes, quaternary ammonium compounds, dehydroacetic acid, phenyl and phenolic compounds, and mixtures thereof. The most preferred preservative is of the 3-lsothiazolone Compounds. Suitable Isothiazolins include 1,2-benzisothiazolin-3-one, available under the tradename PROXEL™ products; and 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, available under the trade name PROMEXAL™. Preferred levels of preservative are from about 0.0001 wt% to 0.5 wt%, more preferably from 0.0002 wt% to 0.2 wt%, most preferably from 0.0003 wt%to0.1 wt%.
Colourant and shading dyes:
While it is preferred that the aqueous rinse-treatment compositions do not include a colourant, the compositions may include 0.001 to 2 wt% of a colourant, which may be a dye or a pigment. The colourant may be included in the compositions for a premium look and aesthetically pleasing appearance. Suitable dyes and pigments may be selected from literature. Dyes are well known in the art and are available from a variety of sources. The dyes may also be the so-called shading dyes, which are especially used to render white clothes brighter and whiter.
Shading dyes:
The compositions preferably include a blue or violet shading agent in the range
from 0.0001 to 0.01 wt%.

The shading agents reduce the perception of damage to many coloured garments and increase the perception of whiteness of white garments.
The shading agents are preferably selected from blue and violet dyes of the solvent disperse basic, direct and acid type listed in the colour index (Society of Dyers and Colourists and American Association of Textile Chemists and Colorists 2002).
Preferably a direct violet or direct blue dyes is present. Preferably the dyes are bis-azo, tris-azo dyes or triphendioxazine dye. The carcinogenic benzidene based dyes are not preferred.
Bis-azo copper containing dyes such as direct violet 66 may be used. The most preferred bis-azo dyes have the following structure:


wherein:
ring D and E may be independently naphthyl or phenyl as shown;
R1 is selected from: hydrogen and C1-C4-alkyl, preferably hydrogen;
R2 is selected from: hydrogen, C1-C4-alkyl, substituted or unsubstituted phenyl
and substituted or unsubstituted naphthyl, preferably phenyl;
R3 and R4 are independently selected from: hydrogen and C1-C4-alkyl,
preferably hydrogen or methyl;
X and Y are independently selected from: hydrogen, C1-C4-alkyl and C1-C4-
alkoxy; preferably the dye has X= methyl; and, Y = methoxy and n is 0, 1 or 2,
preferably 1 or 2.
Preferred bis-azo dyes are direct violet 7, direct violet 9, direct violet 11, direct violet 26, direct violet 31, direct violet 35, direct violet 40, direct violet 41, direct violet 51, and direct violet 99.
Preferred solvent and disperse dyes, are selected from, mono-azo or anthraquinone dyes, most preferably, solvent violet 13, disperse violet 27 disperse violet 26, disperse violet 28, disperse violet 63 and disperse violet 77.
A preferred pigment is pigment violet 23.
Examples of suitable organic dyes are disclosed in WO2008/017570. Preferred dyes also include Acid Violet 50 and Acid Blue 98. Polymeric shading/hueing agents are also preferred.
Fluorescent agents:
The composition preferably includes a fluorescent agent (optical brightener). Fluorescent agents are well known and many such fluorescent agents are available commercially. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt%, more preferably 0.01 to 0.1 wt%.

Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. Preferred fluoresces are: sodium 2-(4-styryl-3-sulfophenyl)-2H-napthol[1,2-d]trazole, disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2 hydroxyethyl) amino 1,3,5-triazin-2-yl)]amino}stilbene-2-2' disulfonate, disodium 4,4'-bis{[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'-bis(2-sulfoslyryl)biphenyl.
As with shading dyes, the incorporation of the fluorescer into the compositions can be used, both, to protect the fluorescer from unwanted interaction with other components and/or to ensure that there is carry-over of the agent into the rinse to improve deposition.
In addition to the essential ingredients described above, the compositions may also include one or more optional ingredients as described below.
Optional ingredients
Heavy metal ion sequestrants:
Some organic acids are known to have sequestering property. An example is citric acid. Where the organic acid, does not provide sufficient heavy metal ion sequestration, a further sequesterant may be added. Heavy metal ion (HMI) sequestrants may prove to be useful components herein for optimum whiteness and HMI control. By heavy metal ion sequestrants is meant components which act to sequester (chelate) heavy metal ions. These components may also have calcium and magnesium chelation capacity, but preferentially they bind heavy metal ions such as Iron, Manganese and Copper. These compounds are even more desired when the water is a tap water of poorer quality and consequently which includes a high level of HMI.

Heavy metal ion sequestrants are preferably present at a level of from 0.005 wt% to 5 wt%, more preferably from 0.1 wt% to 3 wt%, most preferably from 0.2 wt% to 1 wt%. Suitable heavy metal ion sequestrants include the organo aminophosphonates, such as the amino alkylene poly (alkylene phosphonates) and nitrifo trimethylene phosphonates. Preferred organo aminophosphonates are diethylene triamine penta (methylene phosphonate) and hexamethylene diamine tetra (methylene phosphonate). Other suitable heavy metal ion sequestrant is Ethylenediamine-N,N'-disuccinic acid (EDDS).
Stabilising agents and viscosity:
It is preferred that in the absence of any thickening agent, the viscosity of the aqueous rinse treatments compositions is 1.8 cP to 5.0 cP, more preferably 1.8 cP to 2.5 cP. The viscosity is measured at 25 °C on a HAAKE™ viscometer model VT550 using spindle number MV1. When an emulsion of the amino functional polydimethylsiloxanes is used, it is preferred to have an ingredient that will provide better stabilisation of the emulsion, and thereby, of the rinse treatment composition. It is preferred that the composition includes 0.01 wt% to 3 wt%, preferably 0.5 wt% to 2 wt%, more preferably from 0.1 wt% to 1 wt% stabilising agent selected from xanthan gum or derivatives thereof, alginate or a derivative thereof, polysaccharide polymers such as substituted cellulose materials like ethoxylated cellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose and mixtures thereof. Hydroxymethylcellose is the most preferred. When such thickening agents are present, viscosity of the composition may be higher than 1.8 cPs to 5.0 cPs.
Pearlisinq agent:
The compositions may also include a pearlising agent, and such pearlising agents are well known in the art. Pearlising agents are generally included in shampoos, liquid soaps and cosmetic lotions. Any suitable pearlising agent may be used.

When present, the pearlising agent is preferably from 0.0001 to 0.5 wt%, more preferably from 0.01 wt% to 0.4 wt%, and most preferably from 0.1 wt% to 0.2 wt%. Use of stabilising agents as described above, may be particularly beneficial when the compositions include pearlising agents. When such pearlising agents are used, the resultant compositions may no longer be transparent, and may be termed as partially transparent, or translucent.
It is preferred that the compositions are free of anionic surfactants. Anionic surfactants may cause foam in the rinse-liquor, rather than preventing foam. One skilled in the art knows what anionic surfactants are.
Form of the composition
The composition of the invention may be in a liquid, or a liquid-gel form. For better dispersibility, it is preferred that the composition is a liquid. The term liquid means a flowable watery material. As already described above, viscosity of the compositions is preferably 1.8 cP to 5.0 cP. In a liquid-gel form, the viscosity may be higher.
Package:
The composition is preferably packaged in bottles or sachets. The compositions may be sold at lower solids content, or alternatively, at higher solids content, i.e. in a concentrated form. Such concentrated compositions may be diluted in-store, and sold in a ready-to-use form. Commercial distributors and vendors may purchase the concentrated compositions, add water to dilute it to the required dilution level, and sell them. The concentrated compositions may be free of additives, such as perfume, colourants and other ingredients that are variant specific. These additives may be added by the commercial distributors and vendors in supermarkets. Such concentrated compositions may also be sold in special packs having graduations, so that the end user may dilute the contents with water up to a given mark.

Process, method, use and kit:
In accordance with a second aspect, the invention provides a process for preparing an aqueous rinse treatment composition of the first aspect, which includes a step of adding the cationic compound, the amino functional polydimethylsiloxane, the non-ionic surfactant, the organic acid and the rheology modifier to water to form a mixture, and agitating the mixture to form said composition.
In a preferred process, the amino functional polydimethylsiloxane is emulsified to form an emulsion, and this emulsion includes the non-ionic surfactant; at least some of the organic acid, and the rheology modifier; and this emulsion is mixed with the cationic compound in presence of water to get the aqueous rinse treatment composition.
The process may be carried out by simple mixing of the ingredients, and any suitable mixer or blender may be used to mix the ingredients. The process is preferably carried out at 25 °C to 30 °C.
In accordance with a third aspect, the invention relates to a method of rinsing fabrics which includes a step of contacting the fabrics with an aqueous solution of the composition of the first aspect, where the fabrics have been previously contacted with a detergent composition. It is known that consumers first soak soiled clothes in an aqueous solution of a powder detergent composition. Thereafter, some consumers also apply a direct application bar, such as an NSD bar onto heavily soiled areas, before the clothes are rinsed. The method may be particularly useful in such cases, where the detergent composition is a non-soap detergent (NSD) bar. it is preferred that in the method, the composition is used in a first rinse, so that further rinsing may be avoided.
In accordance with a fourth aspect, the invention relates to use of a composition of the first aspect for rinsing fabrics which have been cleaned with a detergent composition.

A preferred use is when the rinse-treatment composition includes a perfume. In such cases, as further preferred use is to provide high perfume impact on damp clothes. The aqueous solution that includes an anionic surfactant, carried over from the wash-cycle, may be a wash-liquor or a rinse-liquor generated during washing or cleaning articles, in particular, clothes. In use, it is preferred that the user doses 10 ml to 12 ml of the composition to about 10 litres of the rinse water, i.e. clean water that is used for rinsing clothes. The user may swirl the water for 5 to 10 seconds, and then add the clothes one-by-one, or at one go. Alternatively, the user may first add the clothes to the water, and then dose the composition. End results would not differ significantly. The dosage of the composition may be increased by the user to reduce visible foam, and this inherently depends on the % AD (active detergent) level of the detergent composition used for cleaning the clothes.
In accordance with a fifth aspect, the invention relates to a kit which includes a composition of the first aspect; and, a set of instructions on use of the
composition.
The invention will now be explained in greater details with the help of the following non-limiting examples.
EXAMPLES
Example-1
A series of experiments were planned to arrive at preferred compositions that have lower turbidity, better stability, especially at elevated temperature; lower phase separation, and better performance, especially in the ability to provide an acceptable level of foam reduction.
Table-1 describes the general formulation of a rinse treatment composition. Several compositions were made by varying ingredients of the silicone emulsion.

Eleven comparative compositions were made (Composition code 1-11 of table-2). Two preferred compositions were made (Composition code 12 and 13 of tabie-2). Details of the silicone emulsions are provided in table-2.
Table-1

Ingredient Wt%
Benzalkonium chloride (50 % strength) 4
Silicone emulsion 0.5 (* see Table-2 below)
Citric acid 1
Preservative 0.01
Perfume 2.5
Water to 100
Table-2

Composition code Ingredients in
silicone
emulsion Wt% Composition code Ingredients in
silicone
emulsion Wt%
1 PDMS 35-45 2 PDMS 30-40

Silica 0.5-5
Silica 0.5-5

PEG-10 PDMS copolymer 10-15
PEG-10 PDMS copolymer 2-12

Ceteareth-60 1-10
Water balance

Cetearyl alcohol 1 -7

Water balance

Composition code Ingredients in
silicone
emulsion Wt% Composition code Ingredients in
silicone
emulsion Wt%
3 PDMS 25-35 4 PDMS 25-35

Silica 0.5-5
Silica 0 5-5

PEG-10 PDMS copolymer 5-15
PEG-10 PDMS copolymer 8-20
Water Balance Water Balance

Table-2 continued

Composition code Ingredients in
silicone
emulsion Wt% Composition code Ingredients in
silicone
emulsion Wt%
5 PDMS 25-35 6 PDMS 30-40

Silica 0.5-5
Silica 0.5-5

PEG-10PDMS copolymer 8-20
PEG-10PDMS copolymer 8-20

Ceteareth-60 8-15
Ceteareth-60 8-15

Cetearyl alcohol 1 -7
Cetearyl alcohol 1 -7

Water Balance
Water balance
Composition code Ingredients in
silicone
emulsion Wt% Composition code Ingredients in
silicone
emulsion Wt%
7 PDMS 30-40 8 PDMS 30-40

Silica 0.5-5
Silica 0.5-5

PEG-10PDMS copolymer 12-20
PEG-10PDMS copolymer 15-25

Ceteareth-60 8-15
Ceteareth-60 5-10

Cetearyl alcohol 1-7
Cetearyl alcohol 1 -3

Trideceth -3 1-5
Trideceth -3 1 -5
Water Balance Water balance
Composition code Ingredients in
silicone
emulsion Wt% Composition code Ingredients in
silicone
emulsion Wt%
9 PDMS 25-35 10 PDMS 10-25

Silica 0.5-5
Silica 0.5-5

PEG-10PDMS copolymer 8-20
PEG 10-PDMS copolymer 4-10

Ceteareth-60 1 -10
Water balance

Glycerol Monostearate 10-20

Trideceth -3 1 -5

Water balance

11 PDMS 15-25 12 Wacker UL 7722M1 (without PDMS and fumed silica) 0.5

Silica 0.5-5

PEG 10 PDMS copolymer 4-10

Water balance

Composition code Product code of the amino silicone emulsion Wt%
13 WackerUL 7722M1 (which has PDMS and fumed silica) 0.5

Note: In the above table, PDMS means polydimethylsiloxane, and PEG means polyethyleneglycol. The pH of 0.2 wt% solutions of compositions 12 and 13 were 5.5. The pH of 0.2% solutions of compositions 1 to 11 was 5.0 to 5.5.
The compositions were observed for phase separation (by way of visible flakes or floating oily layer) after overnight storage at 45 °C; performance on antifoaming activity, and tendency of the composition to foam. The observations are shown in table-3 below.
Table-3

Composition code Observations
1 Phase separation; turbid
2 Phase separation; turbid
3 Phase separation; turbid
4 Phase separation; turbid
5 Phase separation; turbid
6 Phase separation; turbid
7 Phase separation; turbid, and floating visible flakes
8 Phase separation; turbid, and floating visible flakes
9 Phase separation; turbid, and floating visible flakes
10 Phase separation; turbid, and floating visible flakes, comparatively poorer anti-foaming performance
11 Phase separation; turbid, and floating visible flakes, comparatively poorer anti-foaming performance
12 • clear composition
• better antifoaming activity
• no phase separation
• composition itself foamed
13 • clear composition
• better antifoaming activity
• no phase separation
• the composition itself did not foam
Results in table-3, when read with the description in tables 1 and 2 indicate that rinse treatment compositions that included comparative compositions (Code 1 to Code 11 of table-2) showed phase separation, poorer performance on antifoaming activity, and were turbid.

On the other hand, preferred compositions (Code 12 and 13 of table-2) showed better properties. Further, on comparing the results of code 12 with that of code 13, it would be apparent that in code 13, the composition itself had no tendency to foam, while with code-12, the composition itself foamed. Thus, the preferred rinse treatment composition which included Wacker UL 7722M1 (which in turn included polydimethylsiloxane and fumed silica) was better than the composition of code 12. However, composition code-12 also exemplified a preferred composition.
Example-2
An in-house consumer test was conducted to test the efficacy of the composition code-13 of table-2 with trained panellists. Each panellist was asked to bring a normal wash-load of soiled fabrics. Thereafter, each panellist washed own wash-load with a standard (14 % AD) detergent powder. Prior to the rinsing stage, all panellists were asked to dose approximately 10 ml of the composition of table-1 (including a silicone emulsion as per code 13 of table-2) to a bucket containing 8-10 litres of water. Post addition of the composition, the panellists rinsed the clothes in the bucket following their normal rinse habits. Thereafter, each panellist evaluated rinse parameters like amount of lather and soapiness; in water, as well as on fabrics. The panellists used a score card of 0 to 10, 0 being lower on intensity while 10 meant higher intensity. For a comparative evaluation, the rinse-treatment compositions were not added to the rinse water. The results are shown in table-4 below.
Table-4

Formulation Average score for lather Average score for soapiness
Rinse-liquor without adding the composition code-13 5 4
Rinse-liquor + composition code-13 0 1
The results in table-4 indicate that a preferred composition reduced the amount of lather as well as soapiness of the rinse-liquor.

Example-3
Some experiments were designed to compare the quantity of water required to
rinse a wash-load of clothes by using a preferred rinse treatment composition.
Consumers generally use 3 to 4 buckets of water to rinse a single wash-load of
clothes.
Method
Twelve panellists were asked to assess and rate the efficacy of a composition code-13 of table-2. Each panellist was asked to wash and rinse a wash-load of soiled clothes in the usual manner without adding any rinse treatment composition; and wash and rinse another wash-load using the composition code-13. Each wash-load was soaked in a solution of a commercially available detergent powder for two hours. Details of the method are given in table-5.
Table-5

Details First set of 6 panellists Second set of 6 panellists
Wash load 2.2 to 2.5 kg 2.2 to 2.5 kg
French Hardness of water used for soaking and rinsing 24 24
Detergent powder used WHEEL®
(this is a6%A.D.
powder) SURF* Excel Quick Wash (this is a 14 % A.D. powder)
Dosage of the detergent powder 6 grams per litre 3.5 grams per litre
NSD bar directly applied to heavily soiled areas RIN® RIN®
Note. NSD means Non-soap detergent
When the clothes were ready to be rinsed, each panellist was asked to rinse their first wash-load using as much water as they would normally use until they were convinced that the rinse liquor or the clothes were not soapy, and that the rinse liquor had no lather. The quantity of water that was used by each panellist for rinsing the first wash-load was recorded.

Thereafter, each panellist was asked to rinse their second wash-load. In this case, the panellists were asked to dose 10 ml of the preferred composition code-13 to every bucket of water. The quantity of water that was used by each panellist for the second wash-load was also recorded.
The average amount of rinse water was found to be 22 to 45 litres for the first wash-load, and 18 to 35 litres for the second wash-load. It was observed that the average amount of rinse water was comparatively lower when the composition code-13 was used.
Each panellist was also asked to the rate the quantity of water used for rinsing each one of their wash loads on a numerical scale of 1 to 8; where 1 was the least quantity and 8 was very high quantity. On the same scale, they also rated the perfume impact on rinsed damp clothes. The mean scores and their statistical significance at 95% level of confidence are shown in table-6. Each score was an average of 24 data points.

Table-6

Attribute Average scores
First set of 6 panellists without using any rinse-treatment composition First set of 6 panellists using
composition code-13 LSD p-value Significance
Water for rinsing 5.3 2.9 0.753 O.0001

*****
Perfume impact on damp clothes 0.8 6.1 0.893 <0.0001
*****
Attribute Average scores
Second set of 6 panellists without using any rinse-treatment composition Second set
of 6
panellists
using
composition
code-13 LSD p value Significance
Water for rinsing 4.3 2.9 0.99 0.01
******
Perfume impact on damp clothes 5.9 6.9 0.933 0.033
*****
Note: LSD stands for Least Significance Difference
The scores indicate that the panellists used a statistically significant lower quantity of water for rinse when they used the preferred composition. Surprisingly, use of preferred composition also resulted in a statistically higher perfume impact on damp clothes.
It will be appreciated that the illustrated examples provide for an aqueous rinse treatment composition which is homogenous and clear. It will also be appreciated that the illustrated examples provide for an aqueous rinse treatment composition which shows better antifoaming activity, and relatively lower phase separation, especially on overnight storage at 45 oC. It will also be appreciated that the illustrated examples provide for an aqueous rinse treatment composition having relatively lower tendency to foam upon agitation.

The examples also provide aqueous rinse treatment compositions that help reduce the quantity of water used for rinsing clothes, thereby reducing the consumption of water and the associated environmental impact.
It should be understood that the specific forms of the invention herein illustrated and described are intended to be representative only as certain changes may be made therein without departing from the clear teachings of the disclosure.
Although the invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims:
1. An aqueous rinse treatment composition having pH less than 7,
comprising:
(i) a cationic compound;
(ii) an amino functional polydimethylsiloxane;
(iii) a non-ionic surfactant;
(iv) an organic acid; and,
(v) a rheology modifier.
2. An aqueous rinse treatment composition as claimed in claim 1 wherein said composition comprises polydimethylsiloxane and fumed silica.
3. An aqueous rinse treatment composition as claimed in claim 1 or 2 wherein amine number of said amino functional polydimethylsiloxane is at least 0.6 mg/KOH per gram.
4. An aqueous rinse treatment composition as claimed in any one of the preceding claims wherein said organic acid is selected from citric acid, succinic acid, polyacrylic acid, acetic acid, boric acid, malonic acid, adipic acid, fumaric acid, lactic add, glycolic acid, tartaric acid, tartronic acid, maleic acid.
5. An aqueous rinse treatment composition as claimed in any one of the preceding claims wherein said rheology modifier is a salt of a carboxylic acid.
6. An aqueous rinse treatment composition as claimed in any one of the preceding claims wherein said cationic compound is selected from Benzalkonium chloride, substituted Benzalkonium chlorides, di(C8-C12)dialkyl dimethyl ammonium chloride, N-(3-chloroallyl) hexaminium

chlorides, benzethonium chloride, methylbenzethonium chloride, Cetylpyridinium chloride, or esterquats.
7. An aqueous rinse treatment composition as claimed in any one of the preceding claims comprising 0.01 wt% to 5 wt% non-ionic surfactant.
8. An aqueous rinse treatment composition as claimed in any one of the preceding claims comprising a perfume.
9. An aqueous rinse treatment composition as claimed in any one of the preceding claims wherein said amino functional polydimethylsiloxane is emulsified to form an emulsion, where said emulsion comprises said non-ionic surfactant, atleast some of said organic acid, and said rheology modifier.
10. A process for preparing an aqueous rinse treatment composition as claimed in claim 1 comprising a step of adding said cationic compound, amino functional polydimethylsiloxane, non-ionic surfactant, said organic acid and said rheology modifier to water to form a mixture, and agitating said mixture to form said composition.
11. A process as claimed in claim 10 wherein said amino functional polydimethylsiloxane is emulsified to form an emulsion, which comprises said non-ionic surfactant; at least some of said organic acid, and said rheology modifier, and said emulsion is mixed with said cationic compound in presence of water, to get said aqueous rinse treatment composition.
12. A method of rinsing fabrics comprising a step of contacting the fabrics with an aqueous solution of the composition of claim 1, where said fabrics have been previously contacted with a detergent composition.

13. Use of a composition as claimed in claim 1 for rinsing fabrics which have been cleaned with a detergent composition.
14. Use as claimed in claim 13 to provide high perfume impact on damp clothes.
15. A kit comprising an aqueous rinse treatment composition as claimed in claim 1, and a set of instructions on use of the composition.