NOVEL COMPOUNDS FOR FABRIC TREATMENT

FIELD OF INVENTION

The present invention relates to compounds having switchable surface properties and process for making such compounds.

The invention has been developed primarily for use in fabric treatment and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use .

BACKGROUND AND PRIOR 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.

Fabrics that exhibit water and oil repellency are highly preferred by users. Water and oil repellency generally means the ability of the fabric to block water and oil from penetrating into the fibers. Extensive efforts have been made to produce fabric surfaces having durable water and oil repellency, as well as improved and durable soil release characteristics. Some methods of treatment are available to impart either one of these properties to a fabric, but it has proven relatively difficult to provide all of these properties to fabrics, for any appreciable length of time. One method for treating fabrics to simultaneously impart

both these characteristics utilises copolymers containing hydrophobic or oleophobic siloxane fluorocarbon based oil and water repellent segments, and hydrophilic soil release segments .

Natural fibers such as cotton and wool exhibit lower water and oil repellency, but when they do become soiled, they are readily cleaned, thus exhibiting easy soil release-ability. On the other hand, synthetic fabrics, notably polyester, exhibit lower level of soil release action during washing, but these fabrics do not get soiled as easily as cotton or wool. It is believed that the surface energy of cotton and other hydrophilic fabrics is high and therefore, cotton easily gets soiled by particulate stains, such as Carbon soot and dirt. On the other hand, the same high surface energy of cotton allows it to be cleaned with relative ease, as the stains are more easily released in water. Synthetic fabrics like Polyester have low surface energies and therefore, their ability to attract particulate stains is much lower as compared to cotton. However, upon being stained, it becomes difficult to remove these stains from such fabrics, as their low surface energy prevents or retards the release of stains.

Thus, the trend of producing fabrics having a natural/ synthetic blend of fibers tends to aggravate the problems because such blends are easily soiled and the absorbed soil is difficult to wash out. As mentioned above, fluorocarbons have been applied to fabrics in attempts to solve this problem by providing limited protection against oily stains due to their oleophobic properties. However, they tend to

worsen the soil release properties, because the aqueous washing medium cannot properly wet the treated substrate, and hence cannot remove the stains. On the other hand, treatment with hydrophilic soil release polymers tends to improve the soil release characteristics.

However, the ability of the fabric to resist and repel water and oil based stains, and more particularly; high surface energy particulate stains such as carbon soot is very limited.

A fundamental physical property of any material is its surface energy. This property is usually expressed in mJ/m ² . Depending on the magnitude of this property, materials may be classified as having high surface energy or low surface energy. This property generally depends on the composition of the substrate; for example, substrates having a surface that contains a significant portion of polar hydrophilic groups, such as hydroxyl, carboxylic acid, amino and the like, generally possess a high surface energy. Conversely, surfaces that contain a significant portion of non-polar hydrophobic groups such as silicone, fluorinated groups, and the like, generally exhibit lower surface energy. It is known that when a polar liquid such as water is placed in contact with the surface of a substrate, the liquid spontaneously wets the surface only if the surface tension of the liquid is lower than the surface energy of the substrate. Conversely, if the surface tension of the liquid is higher than the surface energy of the substrate, spontaneous wetting does not readily occur, and the liquid remains pooled on the surface of the substrate.

- A -

It is desirable for a porous or stainable surface, such as fabric surface to exhibit high contact angles versus a variety of liquids, to prevent adsorption or staining. It would also be desirable for such surfaces to adapt to a change in their environment, such as in a cleaning or conditioning medium, to enhance removal of stains and soil.

Highly desirable would be a surface that reversibly adapts to its environment, such that the surface is stain resistant as well as easily cleanable and retains this ability through a number of use cycles.

US6899923 B2 (MILLIKEN & CO, 2005) describes a method of imparting durable repellency and stain release to a substrate in which the substrate is coated with a composition comprising of a hydrophilic stain release agent, a hydrophobic stain repellency agent, and a hydrophobic cross-linking agent, which is followed by heating the substrate to remove the excess liquid from the coated substrate; and optionally, further heating the coated substrate .

In another approach, US6818253 B2 (MILLIKEN & CO, 2004) provides a method for treating substrates to obtain durable water repellency and improved durable soil release attributes, in which a mixture having a fluorocarbon polymer and a hydrophilic soil release polymer with ratio in the range of 1:1 and 5:1 and pH between 4 and 7 is applied to a fabric substrate, followed by drying. It is said that the hydrophilic soil release polymer is cationic in nature.

It can be seen that the above methods are sequential and involve multiple stages, and therefore are cumbersome for use in everyday life; and more specifically, at the users' end.

On the other hand US5446114 A (SILTECH INC, 1995) describes the preparation of fluorinated dimethicone copolyols by the reaction between silanic hydrogen containing silicone polymer with vinyl containing fluoro compounds and an allyl alcohol alkoxylate. The presence of both hydrophilic and hydrophobic side chains on a silicone backbone make these polymers good candidates for imparting switchable properties to surfaces, especially fabrics. A major limitation of these polymers, which the present inventors have observed is that these polymers, cannot be effectively delivered onto fabrics through aqueous media.

Therefore, there exists the need for compounds that exhibit switchable property and which can be effectively delivered onto fabrics through aqueous media.

In this context, the present inventors have found that for effective deposition on fabric surface, the compounds must have some organofunctional groups. During wash or rinse treatment, such compounds having switchable properties and containing organofunctional groups would deposit onto and also bind effectively with the fabric surface, thereby simultaneously allowing for co-existence of low and high surface energy segments for soil repellency and soil release benefits, respectively. Such treated fabrics would exhibit low interfacial energies in both air (hydrophobic) and water

(hydrophilic) environments, and therefore hold potential for minimizing adhesion and facilitating release of soils and stains from its surface in both air and water.

The present invention relates to compounds that exhibit auto-adaptable (switchable) surface energy properties and their use in treatment of fabrics.

Such surface energy properties provide relatively high advancing and receding contact angles for liquids when in contact with the fabric. In particular, the fabric surface exhibits low surface energy of at most, about 20 mJ/m ² , as measured by Goniometry and calculated by Fowkes equation, at a temperature of about 25 °C . This unique ability for automatic surface energy modification, in turn, provides surfaces those are both water and oil repellent, and which would exhibit high degree of stain resistance, and stain release in aqueous media. In addition, this unique surface energy profile is repeatable and reversible, depending on the exposure environment.

OBJECT OF THE INVENTION

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art .

It is an object of the invention to provide a compound that exhibits switchable properties and which can be delivered onto fabric surface through aqueous medium.

SUMMARY OF THE INVENTION

According to the principal aspect of the present invention there is provided a compound of the general formula (I) :

:D

where Rl is a group selected from alkyl, branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon groups containing 1 to 50 carbon atom(s), "X" is a hydrophilic polymer chain or segment, "Y" is a hydrophobic or oleophobic polymer chain or segment; "z" is a chain containing an organofunctional group which is an amide, quaternary ammonium, phosphate or sulfate group; R2 is same as Rl, or is Hydrogen, hydroxyl group or a spacer that links said compound of the formula (I) with another compound of the same formula; and a, b, c, d and e are integers from 1 to 4,000.

According to another aspect of the invention there is provided a process for preparing a compound according to the principal aspect; comprising comprising a step of reacting a compound having the general formula (II);

(H)

where Rl is a is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1-50 carbon atoms (s) ; "r" is an integer from 1 to 1000 and "s" is an integer from 4 to 16000, with all of the following:

(a) a hydrophilic polymer having a reactive group which binds covalently to said compound II through the Si-H bond,

(b) a hydrophobic or oleophobic polymer having a reactive group, which binds covalently to said compound-II through the Si-H bond,

(c) a compound containing an organofunctional group which is an amide, quaternary ammonium, phosphate or sulfate group, said compound further having a reactive group which binds covalently to said compound of the formula II through the Si-H bond; and

(d) when said R2 in said compound of the formula (I) is said spacer; a spacer compound selected from the group consisting of alpha, omega dienes; alpha, omega diynes; alpha, omega ene-ynes, or dialkenyl or dialkynyl terminated polymers selected from polysiloxanes or polyethers; said

process being carried out in the presence of a catalyst, and optionally in the presence of an organic solvent or silicone fluid.

According to another aspect of the invention there is provided a method of treating fabric with a compound according to the principal aspect of the invention comprising a step of contacting the fabric with an aqueous dispersion of the compound.

DETAILED DESCRIPTION

It is to be understood that the general formula (I) is a representative structure of the compound. As us the case with products of random graft/co-polymerization, in the actual product, the repeating groups will be randomly distributed.

It is preferred that in the compounds of the present invention, the hydrophilic polymer chain or segment has poly (alkylene oxide), poly (propylene oxide), poly (vinyl alcohol), polysaccharide or poly (acrylic acid) units. More preferably, the hydrophilic polymer chain or segment contains poly (ethylene oxide) and poly (propylene oxide) units, as their surface energies are significantly high, generally in the range of 35 to 50 mJ/m2.

It is preferred that in the compound of the present invention, the hydrophobic or oleophobic polymer chain or segment contains perfluoropolyether, fluorocarbon, polystyrene or polymethylmethacrylate units. Polymer chains

containing fluorocarbon or perfluoropolyether residues are highly preferred as they offer substantially high degree of hydrophobicity and oleophobicity, owing to their extremely low surface energies, generally from 12 to 34 mJ/m ² .

The organofunctional group is an amide, quaternary ammonium, phosphate or sulfate group. Further, it is preferred that all the groups are quaternary ammonium groups, as presence of these groups allows for enhanced deposition of the compound onto the fabric surface, in aqueous media.

Preferably, each of the Rl groups in the compound of the formula (I) is a methyl, ethyl, propyl, butyl, or tertiary butyl group; and more preferably all are methyl groups.

The preferred range of each of a, b, c, d and e in the compound of the present invention is from 10 to 1000.

Silanic hydrogen functional silicones

The Silanic hydrogen (Si-H) containing silicone (either linear or cyclic) , which are used as a "base polymer" to make the compound of the present invention can be represented by the following general formula:

where Rl is a is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon group containing

1-50 carbon atoms (s) ; "r" is an integer from 1 to 4000 and "s" is an integer from 4 to 16000.

It is preferred that "r" is from 100 to 1000 and "s" is from 40 to 4000.

It is preferred that each of the Rl groups is a methyl, ethyl, propyl, butyl or tertiary butyl group. It is further preferred that all Rl groups are methyl groups.

The silanic Hydrogens (Si-H) react with the respective reactive groups of the hydrophilic polymer, hydrophobic or oleophobic polymer, and the compound having an organofunctional group containing Nitrogen, Oxygen, Phosphorus or Sulphur. These reactants react with and bind covalently to the base polymer through the Si-H bond. When the spacer compound is included in the reaction mixture, some Silanic Hydrogens react with the reactive sites of the spacer compound, which further reacts with another molecule of compound of the formula (I), because of the difunctional nature, to form 3-dimensional cross-linked structures.

Hydrophobic or Oleophobic polymer or chain segment

Preferred polymers contain perfluoropolyether, fluorocarbon, polystyrene or polymethylmethacrylate units. Further preferred polymers are selected from vinyl containing fluorocarbons having the following structures, CH2=CH- (CF2)n-CF3 or CH2=CHCH2OCH2CH2 (CF2 ) nCF3 where n=l to 20.

Hydrophilic polymer

Preferred hydrophilic polymers contain poly (alkylene oxide), poly (propylene oxide), poly (acrylic acid), poly (vinyl alcohol or polysaccharide residues. It is preferred that the hydrophilic polymers contain poly (alkylene oxide) and poly (propylene oxide) residues. It is further preferred that the hydrophilic polymers have the structure CH2=CHCH2-O- ( (EO) a- (PO)b- (EO) -H where EO is - (CH2CH2O) - and PO is - (CH2-CH (Me) -0) -, and a, b & c are integers ranging from 1 to 20.

Compound having an organofunctional group

The organofunctional group is an amide, quaternary ammonium, phosphate or sulfate groups. Preferred are quaternary ammonium groups. It is essential that the compounds having the above organofunctional groups also have a reactive group such as vinyl, allyl or propargyl; so that the compounds may react with the Silanic Hydrogens present on the Silicone backbone represented by (II) above followed by conversion into quaternary amino groups .

Spacer compound

When used during the synthesis of the compound of the invention, the base polymer chains are covalently linked to each other through the difunctional spacer groups. These difunctional spacer groups prevent excessive three- dimensional crosslinking, and instead help in forming mildly crosslinked elastomeric compounds. Preferred spacer

compounds are selected from di alkenyl polyethers, alpha, omega dienes, alpha, omega diynes; alpha, omega ene- ynes or di alkenyl or dialkynyl terminated polysiloxanes . Suitable examples of alpha, omega-dienes are 1, 4-pentadiene, 1,5- hexadiene, 1, 7-octadiene; 1, 8-nonadiene, 1, 9-decadiene,

1, 11-dodecadiene, 1, 13-tetradecadiene and 1, 19-eicosadiene . Suitable examples of alpha, omega-diynes are 1, 3-butadiyne or 1, 5-hexadiyne, whereas alpha, omega ene-yne is preferably hexene-5-yne .

It is preferred that the spacer groups are siloxane based. Di-alkenyl terminated polysiloxanes, which are useful as spacer groups can be represented by the following general formula :

wherein Rl is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, or alkynyl or fluorocarbon group containing 1 to 50 carbon atoms; where p is an average and is a number with a value in the range of 2-10000.

Preferred di-alkenyl terminated polyethers can be represented by the following general formulae:

R = divalent moiety

where "n" and "m" are integers from 1 to 10. Suitable divalent moeties are selected from -(CH2)-; or -CH(Me)-; and the like.

Catalysts

It is preferred that the reaction is carried out in the presence of a suitable addition catalyst. These are selected from metal complexes or their compounds or metals in free or immobilized form. Transition metals such as Platinum, Palladium and Rhodium are particularly preferred. Preferred catalysts are Chloroplatinic acid, complexes of Platinum with unsaturated compounds e.g. Platinum (0) -1, 3- divinyl-1, 1, 3, 3-tetramethyldisiloxane complex; Platinum (0) - 2,4,6, 8-tetramethyl-2, 4, 6, 8-tetravinylcyclotetrasiloxane complex; PtO (1,5 cyclooctadine) i.e. Pt(COD)]; Platinum Phospine complexes; Platinum on Carbon; Platinum on inorganic supports such as silica and Platinum black. Other metals such as palladium, rhodium complexes are also suitable for the reaction (for example Wilkinson's catalyst RhCl [ (C6H5) P] 3. More Preferred catalysts are metal complexes or compounds or free metals or immobilized form of Transition metals such as Platinum, Palladium, Rhodium,

Preferable catalysts are Chloroplatinic acid and complexes of platinum with unsaturated compounds. The catalyst can be in heterogeneous phase, e.g., on charcoal or, preferably, in homogeneous phase (e.g. Karstedt catalyst). Platinum (0) - 1, 3-divinyl-l, 1, 3, 3-tetramethyldisiloxane complex was used most preferably.

Solvents and Swelling Agents

The reaction between silanic hydrogen functional silicone base polymer and other reactants is optionally carried out in the presence of a solvent selected from water, a silicone fluid, polar organic compounds, non-polar organic compounds or mixtures thereof. Typically the solvent is present in an amount of 20 to 99.89 wt. % based on the weight of all reactants. More preferably the solvent is present in an amount of from 20 to 80 wt . % and still more preferably from 20 to 50 wt. %. When the solvent is a polar organic compound or non-polar organic compound, an amount should preferably be used to create a product containing <40 wt . % solids. Preferably the solvent is not removed from the composition. Silicone fluids useful as the solvent include, but are not limited to alkyl and/or aryl siloxanes such as methyl siloxanes and alkyl and/or aryl siloxanes containing functional groups. Preferred are volatile methyl siloxanes (VMS) . VMS compounds correspond to the average unit formula (CH ₃ ) _D SiO ( ₄ - _D ) _/ 2 in which j has an average value of 2 to 3. The VMS compounds contain siloxane units joined by Si-O-Si bonds .

Illustrative of such silicone fluids are polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane .

When silicone fluids are used as the solvent herein, the resulting compound is in the form of silicone gels.

Polar organic compounds useful herein include monohydroxy alcohols such as ethyl alcohol and isopropyl alcohol; diols and triols such as propylene glycol, 2-methyl-1, 3-propane diol HOCH ₂ CH(CH ₃ )CH ₂ OH, 1 , 2-hexanediol CH ₃ (CH ₂ ) ₃ CH (OH) CH ₂ OH, and glycerol; glycerol esters such as glyceryl triacetate (triacetin) , glyceryl tripropionate (tripropionin) , and glyceryl tributyrate (tributyrin) ; and polyglycols such as polyethylene glycols and polypropylene glycols, among which are Polypropylene glycol (PPG) 14 butyl ether C ₄ H ₉ [OCH (CH ₃ ) CH ₂ ] I ₄ OH.

Non-polar organic compounds may also be used as the solvent. The non-polar organic compounds include aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, or aromatic halides.

Representative compounds are alcohols such as methanol, ethanol, 1-propanol, cyclohexanol, benzyl alcohol, 2- octanol, ethylene glycol, propylene glycol, and glycerol; aliphatic hydrocarbons such as pentane, cyclohexane, heptane, Varnish Maker's & Painter's (VM&P) solvent, and mineral spirits; alkyl halides such as chloroform, carbon

tetrachloride, perchloroethylene, ethyl chloride, and chlorobenzene; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene; esters such as ethyl acetate, isopropyl acetate, ethyl acetoacetate, amyl acetate, isobutyl isobutyrate, benzyl acetate, and isopropyl palmitate; ethers such as ethyl ether, n-butyl ether, tetrahydrofuran, and 1, 4-dioxane; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether, and propylene glycol monophenyl ether; ketones such as acetone, methyl ethyl ketone, cyclohexanone, diacetone alcohol, methyl amyl ketone, and diisobutyl ketone; petroleum hydrocarbons such as petroleum jelly, mineral oil, gasoline, naphtha, kerosene, gas oil, heavy oil, and crude oil; lubricating oils such as spindle oil and turbine oil; and fatty oils such as corn oil, soybean oil, olive oil, rape seed oil, cotton seed oil, sardine oil, herring oil, and whale oil.

Suitable organic solvents are the ones that do not undergo a chemical reaction with any of the components of the silicone phase, under the anticipated conditions of processing and use and that is suitable for use in the intended end-use application .

The reaction temperature, depending upon the reactants, is in the range of 5°C to 200 ⁰ C and preferably about 80 to 120 ⁰ C and most preferably 110 ⁰ C. The reaction time may vary between 1 minute and 48 hours.

The compounds of the present invention are synthesized by a process comprising a step of reacting a compound having the general formula (II);

(H)

where Rl is a is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1-50 carbon atoms (s) ; "r" is an integer from 1 to 1000 and "s" is an integer from 4 to 16000, with all of the following:

(a) a hydrophilic polymer having a reactive group which binds covalently to said compound II through the Si-H bond,

(b) a hydrophobic or oleophobic polymer having a reactive group, which binds covalently to said compound-II through the Si-H bond,

(c) a compound containing an organofunctional group which is an amide, quaternary ammonium, phosphate or sulfate group, said compound further having a reactive group which binds covalently to said compound of the formula II through the Si-H bond; and

(d) when said R2 in said compound of the formula (I) is said spacer; a spacer compound selected from the group consisting of alpha, omega dienes; alpha, omega

diynes; alpha, omega ene- ynes, or dialkenyl or dialkynyl terminated polymers selected from polysiloxanes or polyethers; said process being carried out in the presence of a catalyst, and optionally in the presence of an organic solvent or silicone fluid.

General Synthetic Strategy

An illustrative synthetic strategy is shown below:

j ila

The invention will now be explained in greater details with the help of the following non-limiting examples.

EXAMPLE - 1

Synthesis of compound according to the invention

In this example, no spacer compound was used; therefore it resulted in linear compound.

The compound was prepared by 3-stage reaction process

Stage 1 : Synthesis of compound of the formula (II), where Rl= methyl groups) which was used as the Silanic hydrogen containing Silicone base polymer.

50 g of octamethycyclotetrasiloxane (also known as D4) and available commercially from GE-Bayer Silicones, was mixed with 15 g of poly (methylhydro siloxane) (CAS Number: 63148- 57-2, also known as MHPS) in a two necked round bottom flask. To the mixture, 1 g of Tulsion catalyst, which is an acidic catalyst (Thermax India, T63MP, sulfonic acid polystyrene resin) was added. The reaction mixture was stirred at 120 °C for 4 hours. Viscous compound of the formula (II) obtained was cooled down to room temperature.

Catalyst was filtered off through Whatman filter paper. Un- reacted D ₄ was distilled off under vacuum at 125 °C . The product obtained was in the form of colorless viscous oil.

Stage 2: Epoxy functionalisation of compound obtained in Stage 1

1 g polyalkylene glycol monoallyl ether i.e. CH2=CHCH2-O- (EO)X- (PO) y-H (where EO is - (CH2CH2O) - and PO is - (CH2- CH(Me)-O)- x and y are each independently integers ranging from 1 to 20) (available commercially as Polyglykol 20-10, Ex-Clariant) and 0.5 g "allyl, IH, IH, 2H, 2H-perfluorooctyl ether" i.e. CH2=CHCH2OCH2CH2 (CF2) nCF3 (Apollo Scientific, UK) ; were dissolved in 50 ml toluene (AR grade) and charged into a moisture-free reflux assembly, maintained under Nitrogen atmosphere. 25 ml of toluene was removed by azeotropic distillation to ensure complete removal of moisture content in the reaction medium. A drop of Platinum catalyst (Platinum (0) -1, 3-divinyltetramethyl-disiloxane complex solution (Available from Aldrich; CAS Number 68478- 92-2) was added to the reaction mixture and the mixture was stirred at room temperature for about 30 minutes. A mixture of 2.5 g of compound from stage 1 and 1ml Toluene (AR grade) was added to the reaction mixture, and the reaction was maintained at about 110 ⁰ C for about 2-3 hrs . Progress of the reaction was monitored by TLC and FT-IR. The percentage

"Si-H" groups dropped to about -75 %. Remaining Si-H groups were reacted with Allyl glycidyl ether (available from Aldrich; CAS Number 106-92-3) . After the reaction was complete, excess toluene and excess allyl glycidyl ether was removed under vacuum. Structure of the compound obtained from Stage-2 is represented below.

n=5

Stage 3 : Quaternization

After complete removal of allyl glycidyl ether, the product from Stage-2 was re-homogenized with toluene (50 ml) . The solution of this product in toluene was transferred to 250 ml round bottom flask. Three ml of ^tert Butyl amine (Aldrich CAS Number: 109-73-9, 99.5%) was added subsequently. The reaction mixture was stirred at 90 °C for 10 hours. The progress of reaction was monitored using NMR (Nuclear Magnetic Resonance) spectroscopy. After the completion of reaction, excess ^tert butyl amine and toluene were removed under vacuum. The obtained amino hydroxyl compound was re- dissolved in toluene. The solution of amino hydroxyl compound in toluene was transferred to 250 ml round bottom flask. Five ml of methyl iodide (CAS Number: 74-88-4, 99.5%) was added subsequently. The reaction mixture was stirred at 70°C for 4 to 5 hours. The viscous product was dissolved in ethanol (concentration - 85 g/1) . The product obtained would have structure that can be represented as follows :

n=5

In this case, R2 was same as Rl i.e. -CH3 (methyl) group.

EXAMPLE 2 (comparative)

In a comparative example, a compound was prepared by following stages 1 and 2 (only) of Example-1. This resulted in a compound having epoxy functional group.

EXAMPLE 3

Above procedure was repeated with divinyl terminated polysiloxane as the spacer in a 4-stage synthesis.

Stage 1 : Synthesis of methylhydrogen functional polysiloxane

As described in stage 1 of Example-1.

Stage 2: Synthesis of divinyl terminated polysiloxane (VTP) copolymer

20 g of octamethycyclotetrasiloxane (also known as D4) was mixed with 4 g of divinyltetramethy-disiloxane (available from Aldrich) in a 50 ml two necked flask. To the mixture 0.3 g of Tulsion catalyst (Thermax, T63MP) was added. The reaction mixture was stirred at 120 deg C for 4 hours.

Divinyl terminated polysiloxane copolymer (VTP) copolymer obtained was cooled down to room temperature. Catalyst was filtered off. Un-reacted D4 was distilled off under vacuum at 125 °C . The product obtained was colorless, viscous oil. This was used as the spacer compound.

Divinyl terminated polysiloxane (VTP) copolymer

Stage 3 : Synthesis of Epoxy functional intermediate

I g polyalkylene glycol monoallyl ether i.e. CH2=CHCH2-O- (EO) a- (PO)b-H (where EO is - (CH2CH2O) - and PO is - (CH2- CH(Me)-O)- a and b are each independently integers ranging from 1 to 20) (Polyglykol 20-10, Clariant) and 0.5 g "allyl, IH, lH,2H,2H-perfluorooctyl ether" i.e. CH2=CHCH2OCH2CH2 (CF2) 5CF3 (Apollo Scientific, UK) and divinyl terminated polysiloxane (synthesized in stage 2) were dissolved in 50 ml toluene (AR grade) and charged into a moisture-free reflux assembly, maintained under Nitrogen atmosphere. 25 ml of toluene was removed by azeotropic distillation to ensure complete removal of moisture content in the reaction medium. A drop of Platinum catalyst (Platinum (0) -1, 3-divinyltetramethyl-disiloxane complex solution (Available from Aldrich; CAS Number 68478-92-2) was

added to the reaction mixture and the mixture was stirred at room temperature for about 30 minutes. A mixture of 2.5 g of compound from stage 1 and one ml Toluene (AR grade) was added to the reaction mixture, and the reaction was maintained at about 110 °C for about 2-3 hrs . Progress of the reaction was monitored by TLC and FT-IR. The percentage "Si-H" groups dropped to about -75 %.

Remaining Si-H groups were reacted with Allyl glycidyl ether (Aldrich; CAS Number: 106-92-3) . After the reaction was complete, excess toluene and excess allyl glycidyl ether was removed under vacuum.

Stage 4 : Quaternization

Procedure followed was same as Stage-3 of Example 1. The final product obtained could be represented by the following structure .

n=5

Example 4

Contact angle study using compound of Examples-1 and 2

10cm X 10cm pieces of cotton cloth (100% cotton, commercially available) were soaked in 50 ml of a 2 wt% solution of the compounds for 15-20 minutes.

The swatches were then dipped in distilled water, soaked for 15 minutes, removed from it and were allowed to dry in oven at 90 °C . Thereafter, the swatches were ironed. A 12cm x 6cm strip of the treated fabric was cut and pasted on a smooth glass slide by applying adhesive to the corners of the fabric. The slide was then placed on the platform of a Goniometer fitted with a camera. A drop of water was placed on the fabric by using a syringe and photographed. By a standard drop shape analysis the contact angle of the drop of water in air on the fabric surface was determined. The change in contact angle with passage of time was recorded and the values have been reproduced in the table-1 below. The experiment was performed in triplicate.

Table 1

Time/seconds Contact angle Contact angle at zero time after 6 seconds

Hydrophobic Hydrophilic

Fabric coated with 120 26 compound of example 1 115 23

120 24

Fabric coated with 120 26 compound of example 1

110 21

120 28

Fabric coated with 0 0 compound of example 2

0 0

0 0

It can be seen that the contact angle at zero time was very high for compounds prepared in Example 1, indicating high degree of hydrophobicity and the same showed gradual reduction and finally came down to -25°, which indicates that the treated fabric was gradually switching from hydrophobic to hydrophilic nature. Therefore, this treated fabric would show high degree of soil repellence in air (i.e. when the treated fabric would be in contact with air) and the same would show high degree of wetting upon placing the same in contact with water. This would enable the fabric to release the stains, when in contact with aqueous medium and more specifically aqueous detergent medium.

On the other hand, fabric swatches treated with compound of Example-2 (comparative example) showed almost zero contact angle, which meant that the fabric was highly hydrophilic at zero time and hence showed high degree of wetting. Such a fabric would easily get soiled by particulate stains in air.

It will be appreciated that the illustrated example, provides for compounds that provides compounds that exhibits switchable properties and that can be delivered onto fabric surface through an aqueous medium.

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 .