Non-fluoro hydrophobic coatings

Abstract

The present disclosure provides polysiloxane-containing coating compositions which are suitable for the production of coatings displaying excellent coating performance properties, such as water repellency (hydrophobicity), good adhesion, resistance to scratch, yellowing and weathering, desired optical properties, anti-fingerprint and easy-to-clean properties, and capable of replacing traditional coating compositions containing fluoropolymer additives.

Description

NON-FLUORO HYDROPHOBIC COATINGSTECHNICAL FIELD

[0001] The present disclosure relates to novel polysiloxane-containing coating compositions used to produce coatings with special properties. The present disclosure further relates to coatings prepared from these compositions.BACKGROUND

[0002] The background description includes information that may be useful in understanding the present invention.

[0003] Coatings with special properties such as hydrophobic, oleophobic, resistance to chemical, corrosion and weathering have been developed in the recent past and have received much attention in the art. Fluoropolymers are one of the major additives used in the manufacture of these coatings. Conventional fluoropolymers used in coatings include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), fluorinated ethylene propylene copolymers (FEP), ethylene tetrafluoroethylene copolymers (ETFE) and fluoroethylene vinyl ether (FEVE). The use of fluoropolymers in coatings has many advantages due to the unique characteristics of these polymers such as, hydrophobicity, high thermal and chemical stability, and resistance to weathering and corrosion. However, use of fluoro materials poses threat to the environment and comes under PF AS regulation.

[0004] Therefore, it is readily apparent that there exists a need for new and improved coating compositions that overcome the afore-mentioned disadvantages of traditional fluoropolymer-containing coating compositions and provide overall satisfactory results. The present disclosure satisfies these needs and provides further related advantages.SUMMARY

[0005] The following presents a summary of this disclosure to provide a basic understanding of some aspects of the invention. This summary is intended to neither identify key or critical elements nor define any limitations of embodimentsor claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure.

[0006] The present disclosure provides novel polysiloxane-containing compositions which are suitable for the production of coatings displaying excellent coating performance properties, such as water repellency (hydrophobicity), oil repellency (oleophobicity). good adhesion, resistance to scratch, yellowing and weathering, desired optical properties, anti-fingerprint and easy-to-clean properties, and capable of replacing traditional coating compositions containing fluoropolymer additives. The compositions disclosed herein can be used to produce coatings on a variety of different substrates, such as glass, plastics, e.g., polycarbonate, metals, and concretes.

[0007] The polysiloxane used in the composition of the present disclosure is a polydimethylsiloxane (PDMS)-based copolymer featuring at least one reactive functional group. These reactive functional groups may include, but are not limited to, alkoxy, trimethoxysilane, hydroxy, epoxy, vinyl hydride, acrylate, isocyanate, or amine groups. Additionally, the PDMS-based copolymer incorporates at least one non-reactive group, such as trialkylsilane, alkyl, or phenyl. The PDMS-based copolymers are characterized by the presence of at least one reactive functional group positioned at the terminal and / or pendant sites within the polymer structure.

[0008] In one embodiment, the polysiloxane has the following Formula (I):m = 1 to 100; n = 1 to 100; p = 1 to 100; m + n + p = 5 to 100; m / n = 0.5 to 20; m / p = 0.5 to 20;X= 0 to 20;Ri, R2 and R3 represent, independently of one another, H, an alkenyl group, an alkyl group, a cycloalkyd group, an aromatic group, a heteroaromatic group, a bicyclic group, -Si(OM)3, -CH2CH2Si(OM)3, - Si(Y)3. alkoxy, amino, epoxy, acrylate, hydroxy, thiol, carboxy, or isocyanate; where,M is an alky l group;Y is selected from an alkyl group, a cycloalkyl group, an aromatic group, a heteroaromatic group, a bicyclic group, and an aliphatic fused ring;R4 is -CH3 or -C2H5; provided that when R2 and R3 are each -Si(CH3)3, then R4 IS -CH2CH2Si(OCH3)3.

[0009] In some embodiments, in Formula I, at least one of Ri, R2 and R3 is a reactive group.

[0010] In some embodiments, in Formula I, R2 and R3 are reactive groups.

[0011] In some embodiments, in Formula I, at least one of Ri, R2 and R3 is a tri alkylsilane.

[0012] In another embodiment, the polysiloxane has the following Formula II:Formula (II) wherein m = 1 to 100; n = 1 to 100; m + n = 5 to 100; m / n = 0.5 to 20;Q is selected from the group consisting of

[0013] In another embodiment, the polysiloxane has the following Formulam / n = 0.5 to 20;Z is selected from the group consisting of

[0014] In the compositions according to the present disclosure, there may be incorporated, in addition to the polysiloxane described herein, other additives generally used in coatings, for example resins, catalysts, cross linkers, solvents and flow agents. These other additives may be used depending on the intended use of the composition. These other additives may be present in the composition within the ranges know n to those skilled in the art.

[0015] The present disclosure also encompasses coatings produced from the compositions of the present disclosure.

[0016] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.DETAILED DESCRIPTION

[0017] The following is a detailed description of embodiments of the present disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0018] Embodiments herein are directed to novel polysiloxane-containing compositions that are suitable for the production of coatings displaying excellent coating performance properties, such as water repellency (hydrophobicity), oil repellency (oleophobicity), good adhesion, resistance to scratch, yellowing and weathering, desired optical properties, anti-fingerprint and easy-to-clean properties, and capable of replacing traditional coating compositions containingfluoropolymer additives. The compositions disclosed herein can be used to produce coatings on a variety of different substrates, such as glass, plastics, e.g., polycarbonate, metals, and concretes.

[0019] The polysiloxane used in the composition of the present disclosure is a polydimethylsiloxane (PDMS)-based copolymer featuring at least one reactive functional group. These reactive functional groups may include, but are not limited to, alkoxy, trimethoxysilane, hydroxy, epoxy, vinyl hydride, acrylate, isocyanate, or amine groups. Additionally, the PDMS-based copolymer incorporates at least one non-reactive group, such as trialkylsilane, alkyl, or phenyl. The PDMS-based copolymers are characterized by the presence of at least one reactive functional group positioned at the terminal and / or pendant sites within the polymer structure.

[0020] In one embodiment, the polysiloxane has the following Formula (I):Formula (I) wherein, m = 1 to 100; n = 1 to 100; p = 1 to 100; m + n + p = 5 to 100; m / n = 0.5 to 20; m / p = 0.5 to 20;X= 0 to 20;Ri, R2 and R3 represent, independently of one another, H, an alkenyl group, an alkyl group, a cycloalkyl group, an aromatic group, a heteroaromatic group, a bicyclic group, -Si(OM)3. -CFhCFbSifOMfs, - Si(Y)3, alkoxy, amino, epoxy, acrylate, hydroxy, thiol, carboxy, or isocyanate; where,M is an alkyl group;Y is selected from an alkyl group, a cycloalkyl group, an aromatic group, a heteroaromatic group, a bicyclic group, and an aliphatic fused ring;R4 is -CH3 or -C2H5; provided that when R2 and R3 are each -Si(CH3)3, then R4is -CH2CH2Si(OCH3)3.

[0021] In some embodiments, in Formula I, at least one of Ri, R2 and Rs is a reactive group.

[0022] In some embodiments, in Formula I, R2 and R3 are reactive groups.

[0023] In some embodiments, in Formula I, at least one of Ri, R2 and Rs is a tri alkylsilane.

[0024] The term “alkyl’’ as used herein refers to a straight-chain or branched- chain alkyl radical containing from 1 to 20, preferably 1 to 10, and more preferably 1 to 6, carbon atoms. With particular preference the term “alkyl” stands for methyl or ethyl.

[0025] The term “cycloalkyd” as used herein refers to a saturated or partially unsaturated (for example, a cycloalkenyl group) cyclic group that contains one or more rings, and contains from 3 to 14 ring carbon atoms, preferably from 3 to 10 ring carbon atoms.

[0026] The aromatic group contains one or more rings containing from 6 to 14 ring carbon atoms, preferably from 6 to 10 ring carbon atoms. The aromatic group refers furthermore to groups that are substituted by fluorine, chlorine, bromine or iodine atoms or by OH, SH, NH2, N3 or NO2 groups. Examples are the phenyl, naphthyl, biphenyl or anilinyl.

[0027] The heteroaromatic group contains one or more rings containing from 5 to 14 ring atoms, preferably from 5 to 10 ring atoms, and contains one or more oxygen, nitrogen, phosphorus or sulfur ring atoms, preferably O. S or N.

[0028] The term “bicyclic” as used herein refers to a bicyclic ring system, i.e. carbocyclic or heterocyclic, saturated or having one or more units of unsaturation, having one or more atoms in common between the two rings of the ring system.Thus, the term includes any permissible ring fusion, such as ortho-fused or spirocyclic.

[0029] In various embodiments, the length of the PDMS co-polymer is controlled to maintain a total unit (m + n + p) variation within the range of 5 to 100.

[0030] Preferably, the ratio of m to n and the ratio of m to p in the polysiloxane of formulae (I), (II) and (III) is in the range of 0.5: 1 to 20: 1. Such ratios are highly advantageous in that they impart for example hydrophobic / oleophobic characteristics to the polymer.

[0031] In one embodiment, R.4 is -CH2CH2Si(OCH3)3; and R2 and R3are each -SI(CH3)3.

[0032] In cases where R4 is -CH3and R2 = R3, the substituent Ri may be distinct and independently selected. Alternatively, if R2 and R3represent reactive groups (e.g., -Si(OM)3), the substituent Ri may be the non-reactive silane -Si(Y)3, and vice versa. In some embodiments, R2 and Rs may constitute a combination of reactive silane (e.g., -Si(OM)3or -CH2CH2Si(OM)3) and non-reactive silane (e.g., -Si(Y)3).

[0033] In one embodiment, R4 is -CH2CH2Si(OCH3)3; R2 and R3are each - Si(CH3)3; and Ri is -Si(Y)3.

[0034] In another embodiment, the poly siloxane has the following Formula (II):Formula (II) wherein m = 1 to 100; n = 1 to 100;m + n = 5 to 100; m / n = 0.5 to 20;Q is selected from the group consisting of

[0035] In another embodiment, the polysiloxane has the following Formula (III):Formula (III) wherein m = 1 to 100; n = 1 to 100; m + n = 5 to 100; m / n = 0.5 to 20; Z is selected from the group consisting of

[0036] The poly siloxane of Formula (I), (II) or (III) can be incorporated in coatings applied to various substrates. The incorporation of the polysiloxane of the present disclosure in a coating provides hydrophobic as well as oleophobic properties to the coating after its final curing, thus providing anti-fingerprint or easy-to-clean properties to the cured coating.

[0037] In various embodiments, the polysiloxane of formula (I), (II) or (III) can be used in the coating composition in an amount of 0.01-50% w / w, based on the total weight of the composition. Preferably , the amount of the poly siloxane is between 0.01% and 20% w / w.

[0038] In the compositions according to the present disclosure, there may be incorporated, in addition to the polysiloxane described herein, other additives generally used in coatings, for example resins, catalysts, cross linkers, solvents and flow agents, depending on the intended use of the composition. These other additives may be present in the composition within the ranges known to those skilled in the art. Preferably, these other additives may be used in the inventive compositions in a total amount ranging from 1% to 99.9% w / w, based on the total weight of the composition.

[0039] In one embodiment, the present disclosure provides a coating composition which can be used to produce hydrophobic and easy-to-clean coatings on glass substrates. Said glass coating composition comprises a polysiloxane of formula (I), (II) or (III), a resin, a cross-linker, an acid catalyst, a curing catalyst, solvent(s), and a flow agent.

[0040] In certain embodiments, the glass coating composition comprises, based on the total weight of the composition:0.01-50% w / w of a polysiloxane of formula (I), (II) or (III),10-60% w / w of a resin,1-30% w / w of a cross-linker,0.1-10% w / w of an acid catalyst,0.01-5% w / w of a curing catalyst,20-80% w / w of solvent(s), and0. 1-10% w / w of a flow agent.

[0041] In one embodiment the present disclosure provides a coating composition which can be used to produce water-repellent coating on concrete, porous concrete and fibre board. Said coating composition comprises a polysiloxane of formula (I), (II) or (III) and one or more solvents capable of partially or fully dissolving the polysiloxane.

[0042] In one embodiment, the present disclosure provides a hard coat composition having a contact angle of more than 95 degrees.

[0043] In certain embodiments, the coating composition used to produce water-repellent coating on concrete, porous concrete or fibre board comprises, based on the total weight of the composition:0.01-50% w / w of a polysiloxane of formula (I), (II) or (III), and20-80% w / w of solvent(s) capable of partially or fully dissolving the poly siloxane.

[0044] The method of preparing the coating composition of the present disclosure, including those mentioned later herein, is not particularly restricted but any of the method known in the art can be used, for example the method comprising mixing or blending a composition containing a polysiloxane of formula (I), (II) or (III) and other additives using a mixer, blender, or the like.

[0045] The present disclosure also encompasses coatings produced from the compositions of the present disclosure.

[0046] In one embodiment, the present disclosure provides a coating composition used as anti-fingerprint coatings.

[0047] In one embodiment, the present disclosure provides a coating composition used as easy-to-clean coating.

[0048] In one embodiment, the present disclosure provides a coating composition used as chemical resistance coating.

[0049] Further embodiments of the present disclosure are provided in the following.

[0050] Embodiment 1 : A coating composition for coating onto a substrate, the composition comprising a polysiloxane, wherein the polysiloxane is apolysiloxane of formula (I); or wherein the polysiloxane is a polysiloxane of formula (II); or wherein the poly siloxane is a poly siloxane of formula (III).

[0051] Embodiment 2: The composition of one or more of Embodiments 1- 13, wherein in formula (I), at least one of Ri, R2 and R3 is a reactive group; or R2 and R3 are reactive groups; or at least one of Ri, R2 and R3 is a trialkylsilane.

[0052] Embodiment 3: The composition of one or more of Embodiments 1- 13, wherein in formula (I), R4 is -CH2CH2Si(OCH3)s; and R2 and R3 are each - Si(CH3)3.

[0053] Embodiment 4: The composition of one or more of Embodiments 1- 13, wherein in formula (I), R4 is -CEECEESi OCEE R2 and R are each - Si(CH3)3; and Ri is -SI(Y)3.

[0054] Embodiment 5: The composition of one or more of Embodiments 1- 13, wherein the polysiloxane is present in an amount of 0.01-50% w / w based on a total weight of the composition.

[0055] Embodiment 6: The composition of one or more of Embodiments 1- 13, further comprising one or more additives.

[0056] Embodiment 7: The composition of one or more of Embodiments 1- 13, wherein the one or more additives are selected from the group consisting of a resin, a catalyst, a cross-linker, a solvent, a flow agent, and a combination thereof.

[0057] Embodiment 8: The composition of one or more of Embodiments 1- 13, wherein the one or more additives are present in an amount ranging from 1% to 99.9% w / w, based on a total weight of the composition.

[0058] Embodiment 9: The composition of one or more of Embodiments 1- 13, wherein the substrate is selected from a glass, a plastic, a metal, a concrete, and a fiber board.

[0059] Embodiment 10: The composition of one or more of Embodiments 1- 13, wherein the composition is used to form an anti-fingerprint coating, an easy- to-clean coating, or a chemically resistant coating on a substrate.

[0060] Embodiment 11: The composition of one or more of Embodiments 1- 13, wherein the coating has a contact angle of more than 95 degrees.

[0061] Embodiment 12: The composition of one or more of Embodiments 1- 13, wherein the substrate is a glass, the composition comprising: the poly siloxane of formula (I), (II) or (III), a resin, a cross-linker, an acid catalyst, a curing catalyst, solvent(s), and a flow agent.

[0062] Embodiment 13: The composition of one or more of Embodiments 1- 13, wherein the substrate is a concrete, a porous concrete or a fiber board, the composition comprising: the polysiloxane of formula (I), (II) or (III), and one or more solvents capable of partially or fully dissolving the polysiloxane.

[0063] Embodiment 14: A substrate coated with the coating composition of one or more of Embodiments 1-13.

[0064] Embodiment 15: A method of coating a substrate, the method comprising applying the coating composition of one or more of Embodiments 1- 13 to the substrate and curing the same.

[0065] While the foregoing description discloses various embodiments of the disclosure, other and further embodiments of the invention may be devised without departing from the basic scope of the disclosure. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary' skill in the art.EXAMPLES

[0066] The present disclosure is further explained in the form of following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention. The appropriate procedure to prepare the fragrance compositions w ill be apparent to those skilled in the art.SYNTHESIS EXAMPLESSynthesis of PDMS co-polymer having hydrophobic / oleophobic groups:

[0067] Synthesis Example 1 - Synthesis of bis-hydride terminated PDMS co-polymerStep-1D4-H (0.1 mole) was weighed and placed in a three-neck round-bottom flask (R.B.) equipped with a chilled water condenser, a thermometer, and a pressureequalizing addition funnel. The apparatus was purged with nitrogen to establish an inert atmosphere. The reaction vessel was then heated to 60 °C.Karstedt catalyst (2 ppm) was meticulously added to the D4-H, followed by a thorough nitrogen purge. Subsequently, vinyltrimethylsilane (0.44 moles. 4 equivalents) was introduced dropwise into the reaction mixture. An exothermic reaction was observed after few minutes, and the addition rate was carefully controlled to maintain the internal temperature below 75 °C. Vigorous reflux of vinyltrimethylsilane was observed. The reaction was allowed to proceed for 1 more hour, during which the temperature naturally decreased to 60 °C. A sample was collected NMR analysis, confirming the consumption of Si-H and the formation of new Si-CH2 linkages. The reaction mixture was then subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components and unreacted vinyltrimethylsilane.Step-2: Acid-catalyzed ring opening polymerization (ROP)D4*D4 bis-hydride 1Compound HMMH (2.14 g. 1.59 mmol). D4 (10 g, 2.11 mmol) and D4* (5 g, 0.48 mmol) was taken in a R.B and was charged with Amberlyst 15 (350 mg, 2 wt%) catalyst at RT and was stirred for 8 h at RT. Solid content was checked at this point which showed 86%. It was subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components and was used for next hydrosilylation reaction.By following same procedure loading of HMMH was varied to get different chain length. Also, weight ratios of D4 and D4* were changed to synthesize different co-polymers having different -Si(Me)3 loading.Step-3A: Synthesis of additive containing reactive trimethoxysilane and non- reactive silaneKarstedt Catalyst (2 ppm) bis-hydride 1 Representative list of vinylsilanes () used:Procedure: PDMS bis-hydride-1 (0.5 moles, with a variable chain length of n = 5 to 100) was accurately w eighed and placed in a three-neck round-bottom flask (R.B.) equipped with a chilled water condenser, a thermometer, and a pressureequalizing addition funnel. The apparatus w as purged with nitrogen to establish an inert atmosphere. The reaction vessel was then heated to 60 °C.Karstedt catalyst (2 ppm) was meticulously added to the PDMS bis-hydride solution, followed by a thorough nitrogen purge. Subsequently, trimethoxyvinylsilane (0.55 moles, 1.1 equivalents) was introduced dropwise into the reaction mixture. An immediate exothermic reaction was observed, and the addition rate was carefully controlled to maintain the internal temperature below 75 °C. The reaction was allowed to proceed for 30 minutes, during which the temperature naturally decreased to 60 °C. A sample was collected NMR analysis, confirming the partial consumption of bis-silyl hydride and the formation of new S1-CH2 linkages.Following this, trimethylvinylsilane (0.55 moles, 1.1 equivalents) was introduced dropwise through an addition funnel at a controlled rate, ensuring that the exothermic reaction did not exceed 75 °C. After an additional 30 minutes, NMR analysis indicated the complete consumption of bis-silyl hydride.The reaction mixture was then subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components. The resulting product w as utilized in coating formulation.Step-3B: Synthesis of additive containing reactive trimethoxysilane and non- reactive aliphatic / aromatic alkene moietyKarstedt Catalyst (2 ppm) bis-hydride 1Representative list of alkenesZ ) used:Procedure: PDMS bis-hydride-1 (0.5 moles, with a variable chain length of n = 5 to 100) was accurately weighed and placed in a three-neck round-bottom flask (R.B.) equipped with a chilled water condenser, a thermometer, and a pressureequalizing addition funnel. The apparatus was purged with nitrogen to establish an inert atmosphere. The reaction vessel was then heated to 60 °C.Karstedt catalyst (2 ppm) was meticulously added to the PDMS bis-hydride-1 solution, followed by a thorough nitrogen purge. Subsequently, trimethoxyvinylsilane (0.55 moles, 1.1 equivalents) was introduced dropwise into the reaction mixture. An immediate exothermic reaction was observed, and the addition rate was carefully controlled to maintain the internal temperature below 75 °C. The reaction was allowed to proceed for 30 minutes, during which the temperature naturally decreased to 60 °C. A sample was collected NMR analysis, confirming the partial consumption of bis-silyl hydride and the formation of new Si-CHz linkages.Following this, Dodecene (0.55 moles, 1.1 equivalents) was introduced dropwise through an addition funnel and then heated at 80 °C for 1 h. NMR analysis indicated the complete consumption of bis-silyl hydride.The reaction mixture was then subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components. The resulting product was utilized in coating formulation.

[0068] Synthesis Example 2 - Synthesis of pendant hydride containingPDMS co-polymerStep-1Procedure: HMMH (0. 1 mole) was weighed and placed in a three-neck roundbottom flask (R.B.) equipped with a chilled water condenser, a thermometer, and a pressure-equalizing addition funnel. The apparatus was purged with nitrogen to establish an inert atmosphere. The reaction vessel was then heated to 60 °C.Karstedt catalyst (2 ppm) was meticulously added to the HMMH, followed by a thorough nitrogen purge. Subsequently, vinyltrimethylsilane (0.22 moles, 2.2 equivalents) was introduced dropwise into the reaction mixture. An exothermic reaction was observed immediately, and the addition rate was carefully controlled to maintain the internal temperature below 75 °C. Vigorous reflux of vinyltrimethylsilane was observed. The reaction was allowed to proceed for 1 more hour, during which the temperature naturally decreased to 60 °C. A sample was collected NMR analysis, confirming the consumption of Si-H and the formation of two new Si-CH2 linkages, thereby formation of MM*. The reaction mixture was then subjected to vacuum distillation at 100 °C for 1 hour under high- vacuum conditions (0 psi) to remove volatile components and unreacted vinyltrimethylsilane.Step-2Procedure: Compound MM* (2 g, 5.9 mmol, 1 equivalent), D4 (7.08 g, 23.89 mmol, 4 equivalent), D4* (7.66 g, 11.94 mmol, 2 equivalent) and D4-H (1.43 g,5.9, 1 equivalent) was taken in a R.B and was charged with Amberlyst 15 (350 mg, ~2 wt%) catalyst at RT and was stirred for 8 h at RT. Solid content was checked at this point which showed 86%. It was subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components and was used for next hydrosilylation reaction.By following same procedure, loading of MM* was varied to get different chain length. Also, weight ratios of D4, D4* and D4-H were changed to synthesize different co-polymers having different -Si(Me)3 and Si-H loading.Step-3: Synthesis of additive containing reactive pendant trimethoxysilane and non-reactive terminal trimethylsilaneProcedure: Pendant hydride (0.1 mole) was weighed and placed in a three-neck round-bottom flask (R.B.) equipped with a chilled water condenser, a thermometer, and a pressure-equalizing addition funnel. The apparatus was purged with nitrogen to establish an inert atmosphere. The reaction vessel was then heated to 60 °C.Karstedt catalyst (2 ppm) was meticulously added to the it, followed by a thorough nitrogen purge. Subsequently, trimethoxyvinylsilane (excess) was introduced dropwise into the reaction mixture. An exothermic reaction was observed immediately, and the addition rate was carefully controlled to maintain the internal temperature below775 °C. The reaction was allowed to proceed for 1 more hour, during which the temperature naturally decreased to 60 °C. A sample was collected NMR analysis, confirming the consumption of all Si-H and the formation of two new Si-CH2 linkages. The reaction mixture was then subjected to vacuum distillation at 100 °C for 1 hour under high-vacuum conditions (0 psi) to remove volatile components and unreacted silanes. This was then further used for coating applications.FORMULATION EXAMPLES

[0069] Coating formulations were prepared according to the ingredients and amounts indicated in Table 1.Table 15 MTMS = Methyltrimethoxysilane

[0070] Comparative Formulation ExampleIn a Schott Duran bottle, weigh MTMS and add acetic acid dropwise by maintaining the temperature below 10°C using ice bath. Add the mixture of LudoxAS40 and water dropwise to the above mixture using dropping funnel.10 After completion of addition, continue the stirring for another 16 h at room temperature. Further, add solvent. TBAA, flow and levelling agent BYK302 and continue the stirring for another 4 hrs. Keep the reactionmixture for agig at 50° C for 5 days. After aging, filter the formulation using 0.45JJ. filter and use it for coating glass substrates.

[0071] Formulation Example 1In a Schott Duran bottle, weigh MTMS and add acetic acid dropwise by maintaining the temperature below 10°C using ice bath. Add the mixture of LudoxAS40 and water dropwise to the above mixture using dropping funnel. Then, add the polysiloxane additive-1 slowly to the reaction mixture. After completion of addition, continue the stirring for another 16 h at room temperature. Further, add solvent. TBAA, flow and levelling agent BYK302 and continue the stirring for another 4 hrs. Keep the reaction mixture for aging at 50° C for 5 days. After aging, filter the formulation using 0.45p filter and use it for coating glass substrates.Polysiloxane additive-1

[0072] Formulation Example 2In a Schott Duran bottle, weigh MTMS and add acetic acid dropwise by maintaining the temperature below 10°C using ice bath. Add the mixture of LudoxAS40 and water dropwise to the above mixture using dropping funnel. Then, add polysiloxane additive-2 slowly to the reaction mixture. After completion of addition, continue the stirring for another 16 h at room temperature. Further, add solvent. TBAA, flow and levelling agent BYK302 and continue the stirring for another 4 hrs. Keep the reaction mixture for aging at 50° C for 5 days. After aging, filter the formulation using 0.45p filter and use it for coating glass substrates.Polysiloxane additive-2

[0073] Formulation Example 3In a Schott Duran bottle, weigh MTMS and add acetic acid dropwise by maintaining the temperature below 10°C using ice bath. Add the mixture of LudoxAS40 and water dropwise to the above mixture using dropping funnel. Then, add polysiloxane additive-3 slowly to the reaction mixture. After completion of addition, continue the stirring for another 16 h at room temperature. Further, add solvent. TBAA, flow and levelling agent BYK302 and continue the stirring for another 4 hrs. Keep the reaction mixture for aging at 50° C for 5 days. After aging, filter the formulation using 0.45p filter and use it for coating glass substrates.Polysiloxane additive-3

[0074] Formulation Example 4In a Schott Duran bottle, weigh MTMS and add acetic acid dropwise by maintaining the temperature below 10°C using ice bath. Add the mixture of LudoxAS40 and water dropwise to the above mixture using dropping funnel. Then, add polysiloxane additive-4 slowly to the reaction mixture. After completion of addition, continue the stirring for another 16 h at room temperature. Further, add solvent, TBAA, flow and levelling agent BYK302 and continue the stirring for another 4 hrs. Keep the reaction mixture for aging at 50° C for 5 days. After aging, filter the formulation using 0.45p filter and use it for coating glass substrates.Polysiloxane additive-4Measurement of coating propertiesSteel wool scratch resistance was tested using grade 0000 steel wool taped to a l”xl” end of a bar weighing one Kg. The steel wool side was rubbed back and forth 5 times on the coating. The coating was observed for scratches. The sample passes the test if there are no scratches. The number of scratches observed can be noted for a relative evaluation of failing samples.Crosshatch adhesion testing was done using Waterford test method C-1444, which is similar to ASTM D3359-95a, method B. For this test, a crosshatch pattern is cut in the coating using a Gardner scriber. A piece of tape (3M, Scotch 898) is pressed over the crosshatch, left for about a minute, and removed by quickly pulling on the tape. The adhesion is ranked from 5B toOB, with 5B being the best adhesion, 0% coating loss, and 0B being >65% coating lost.Easy to clean properties: Easy to clean properties were evaluated using Solvent- Based Permanent Ink Marker, Wax Crayon, Ballpoint Ink, Water-based Ink Marker. Water contact angle, water sliding angle. Sebun test for anti-fingerprint on the coated panel (glass, PC, Metal and other substates). The sample passes the test if there are no / slight mark.Easy to clean YES = no marks on surface after wiping; NO = mark exists after wiping.Water contact angle: Contact angle measured using ASTM D5946Coating performance on glass substrates

[0075] The formulation of formulation examples 1 to 4 was applied to glass panel and cured for 60 mins at 150° C. The comparative formulation was also applied and cured using the same procedure to provide a control. Coating performance properties of the formulation examples 1 to 4 were measured and are reported in Table 2.Table 2As can be seen from Table 2, the formulations containing poly siloxane additive display better coating properties compared to comparative formulation which does not contain polysiloxane additive.

[0076] Formulation Example 5In a Schott Duran bottle, 5% solution of the poly siloxane additive- 1 in isopropyl alcohol (IP A) was made and applied on different substrates such as concrete, porous concrete and fibre board. Coating was made using brush coat and cured at room temperature for 24 hrs. Water repellency tests were performed on cured coatings. The results for these tests are provided in Table 3.Table 3As can be seen from Table 3, Formulation example 5 containing the polysiloxane additive displays hydrophobicity or water repellency as measured by contact angle >100 on various substrates.

Claims

We Claim:

1. A coating composition for coating onto a substrate, the composition comprising a polysiloxane, wherein the polysiloxane is a polysiloxane of formula (I):Formula (I) wherein. m = 1 to 100; n = 1 to 100; p = 1 to 100; m + n + p = 5 to 100; m / n = 0.5 to 20; m / p = 0.5 to 20;X= 0 to 20;Ri, R2 and Rs represent, independently of one another, H, an alkenyl group, an alkyl group, a cycloalkyl group, an aromatic group, a heteroaromatic group, a bicyclic group, -Si(OM)s. -CH2CH2Si(OM)s, -Si(Y)s, alkoxy, amino, epoxy, acrylate, hydroxy, thiol, carboxy, or isocyanate; where,M is an alkyl group;Y is selected from an alkyl group, a cycloalkyl group, an aromatic group, a heteroaromatic group, a bicyclic group, and an aliphatic fused ring;R4 is -CHs or -C2H5; provided that when R2 and Rs are each -Si(CHs)s, then R4IS -CH2CH2SI(OCHS)3; or wherein the polysiloxane is a polysiloxane of formula (II):Formula (II) wherein, m = 1 to 100; n = 1 to 100; m + n = 5 to l 00; m / n = 0.5 to 20;Q is selected from the group consisting ofor wherein the poly siloxane is a polysiloxane of formula (III):Formula (III) wherein, m = 1 to 100; n = 1 to 100; m + n = 5 to 100; m / n = 0.5 to 20;Z is selected from the group consisting of2. The composition as claimed in claim 1, wherein in formula (I), at least one of Ri, R2 and Rs is a reactive group; or R2 and Rs are reactive groups; or at least one of Ri, R2 and Rs is a trialkylsilane.

3. The composition as claimed in claim 1, wherein in formula (I), R4 is - CH2CH2Si(OCHs)s; and R2 and Rs are each -Si(CHs)s.

4. The composition as claimed in claim 1, wherein in formula (I), R4 is - CH2CH2Si(OCHs)s; R2 and Rs are each -Si(CHs)s; and Ri is -Si(Y)s.

5. The composition as claimed in claim 1, wherein the polysiloxane is present in an amount of 0.01-50% w / w based on a total weight of the composition.

6. The composition as claimed in claim 1, further comprising one or more additives.

7. The composition as claimed in claim 6, wherein the one or more additives are selected from the group consisting of a resin, a catalyst, a cross-linker, a solvent, a flow agent, and a combination thereof.

8. The composition as claimed in claim 6, wherein the one or more additives are present in an amount ranging from 1% to 99.9% w / w, based on a total weight of the composition.

9. The composition as claimed in claim 1, wherein the substrate is selected from a glass, a plastic, a metal, a concrete, and a fiber board.

10. The composition as claimed in claim 1, wherein the composition is used to form an anti -fingerprint coating, an easy-to-clean coating, or a chemically resistant coating on a substrate.

11. The composition as claimed in claim 10, wherein the coating has a contact angle of more than 95 degrees.

12. The composition as claimed in claim 1, wherein the substrate is a glass, the composition comprising: the poly siloxane of formula (I). (II) or (III), a resin, a cross-linker, an acid catalyst, a curing catalyst, solvent(s), and a flow agent.

13. The composition as claimed in claim 1, wherein the substrate is a concrete, a porous concrete or a fiber board, the composition comprising: the polysiloxane of formula (I), (II) or (III), and one or more solvents capable of partially or fully dissolving the polysiloxane.

14. A substrate coated with the coating composition as claimed in claim 1.

15. A method of coating a substrate, the method comprising applying the coating composition as claimed in claim 1 to the substrate and curing the same.

Images