A silane-based concentrate liquid for high-dilution waterproofing and substrate protection

Abstract

The present invention relates to a silane-based concentrate liquid for high-dilution waterproofing and substrate protection. The concentrate liquid comprises a water-insoluble alkyltrialkoxysilane, a volatile natural oil, a water-soluble silane coupling agent, a bonding polymer, an emulsifier, and a pH-adjusting agent. The concentrate liquid is designed for dilution with potable water in the range of 100 to 200 times (1 part concentrate to 100 to 200 parts potable water), forming a dilute emulsion that provides water-repellence and antimicrobial protection to treated surfaces. The bonding polymer is selected from synthetic and natural resins, while the emulsifier includes non-ionic, cationic, or anionic surfactants. The water diluted emulsion of concentrate liquid is non-flammable, environmentally friendly, and suitable for eco-sensitive environments. A method for preparing the concentrate liquid includes mixing components at specific temperatures, followed by high-shear processing and then diluting with potable water. The dilute emulsion is applied to substrates like concrete, bricks, wood, soil, paper and fabric, offering extended durability and protection.

Description

A SILANE-BASED CONCENTRATE LIQUID FOR HIGH-DILUTION WATERPROOFING AND SUBSTRATE PROTECTIONFIELD OF THE INVENTION

[0001] The present invention relates to the field of waterproofing and substrate protection, specifically to a silane-based concentrate liquid designed for high-dilution applications.

[0002] The present invention is particularly suited for treating porous materials such as masonry, concrete, bricks, wood, fabric, soil, paper and other substrates used in construction, industrial and domestic applications.BACKGROUND OF THE INVENTION

[0003] Water resistance and durable protection against moisture are critical for many surfaces, including concrete, bricks, soil, paper, fabric, wood, and masonry structures. These materials and structures require both water repellence and antimicrobial properties, especially in moisture-prone environments. The ingress of moisture into these materials often leads to a host of issues like cracking, shrinkage, staining, expansion, chemical breakdown, mildew growth, freeze-thaw damage, and corrosion of embedded steel. The moisture induced degradation impacts longevity and functionality of these materials. To address these problems, a range of conventional methods have been employed. Commonly, surfaces of concrete, wood, and bricks are treated with water-repellent polymers and coatings. Soils and cellulosic materials, such as fabric and paper, are treated with bonding polymers to improve both wet and dry durability and add water resistance. However, these traditional methods are often unreliable, costly and may not be environmentally sustainable. Besides polymers, other common water repellents used include non-volatile oils, waxes, bitumen, soaps, resins, and organosilicon compounds. These substances are applied to surfaces using various techniques like air spraying, brushing, rolling, splash wiping, and wet mopping. For using these materials and application techniques, the user needs to carefully analyze the nature of surface and level of protection, to avoid issues of incomplete coverage, ineffective water resistance, structural damage and environmental impact.

[0004] There are various categories of water repellants available, and organosilicon compounds have established themselves as one of the most reliable water repellants in these categories. The use of organosilicon compounds for surface treatment is well -documented and known for imparting water-repellence and antimicrobial properties, thereby ensuring the longevity of treated surfaces. The organosilicon compounds, especially alkyltrialkoxysilanes, have been utilized in organic solvent dispersions for treating surfaces such as concrete, bricks, plasters, stones, and glass.

[0005] For decades, organosilicon compounds, particularly alkyltrialkoxysilanes, have been extensively used in waterproofing masonry and other surfaces. For waterproofing treatment of surfaces, the organosilicon compounds have been used in solutions containing flammable solvents including alcohols and organic hydrocarbons, leading to significant challenges and risks. The challenges include high emissions of Volatile Organic Compounds (VOCs) during application, posing risks of fire hazards, health concerns, and environmental damage. Emission of VOCs from coated surfaces and their short-term and long-term exposure have been known to cause negative impact on health and environment. To mitigate these challenges, focused research has been conducted to develop non-flammable formulations with low VOCs emissions that offer effective water resistance to surfaces such as masonry surfaces and mitigate the associated health risks and environmental impact.

[0006] For non-flammable and low VOC emission formulation with water resistance using the alternative medium, efforts have been made to replace the alcohol and organic hydrocarbonbased solvents with water. With the substitution of alcohol and organic hydrocarbon-based solvents with water, the formulation was made in the form of emulsions containing organosilicon compounds. However, these formulations could not provide water resistance comparable to the solvent-based compositions. To improve the water resistance of these formulations, attempts were made to make alkyltrialkoxysilanes water soluble, by using water- soluble amino and quaternary ammonium organosilanes along with alkyltrialkoxysilanes. Quaternary ammonium organosilanes, widely recognized for their antimicrobial efficacy, are particularly effective in this regard. Even at very low usage levels (1% or lower), quaternary ammonium organosilanes serve as potent antimicrobial agents. Even with these efforts, the water-soluble formulations lacked in comparison to solvent-based formulations in terms of formulation stability, penetration depth, and the beading effect of water (water-repellant effect)on the treated surface (substrate). Even with the availability of these liquids in concentrate form with the ability for dilution in water on site, there are widely reported issues related to various aspects including economy, efficacy and user safety. It is to be noted that materials used in masonry, soils, and cellulosic surfaces are prone to the rapid growth of algae, mold, moss, other microorganisms and a combination thereof, when exposed to moisture. Therefore, beyond water resistance, these materials necessitate inherent antimicrobial properties.

[0007] Accordingly, there exists a need for a silane-based concentrate liquid formulation that, when mixed with water in high dilution and then applied to masonry, soil, cellulosic materials, papers, fabrics and other surfaces, offers low VOCs emissions, safe for both users and the environment, easy to apply, non-flammable, and possesses antimicrobial properties along with superior water repellence.OBJECTS OF THE INVENTION

[0008] The primary object of the present invention is to create a silane-based concentrate liquid for high dilution with potable water, that offers high durability and effective water resistance to protect and extend durability and resistance to environmental degradation of various porous materials, structures and their substrates.

[0009] Further object of the present invention is to create the silane-based concentrate liquid, that maintains stability and efficacy when highly diluted with potable water, making it adaptable for different application techniques including spraying, brushing, rolling, or dipping.

[0010] Further object of the present invention is to create the silane-based concentrate liquid with anti-microbial properties, that inhibits the growth of algae, mold, other microorganisms and a combination thereof, on treated surfaces, thereby enhancing the longevity and cleanliness of the substrates.

[0011] Further object of the present invention is to create the silane-based concentrate liquid, when highly diluted with potable water, have anti-flammable properties and with low VOC emissions, that is environmentally friendly, suitable for use in eco-sensitive environments, and safe for handling and application.SUMMARY OF THE INVENTION

[0012] Embodiments of the present disclosure present technological improvements as solution to one or more of the above-mentioned technical problems recognized by the inventor in conventional practices and existing state of the art. The present invention relates to a silane- based concentrate liquid specifically designed for high-dilution waterproofing and substrate protection. The concentrate liquid is formulated to be diluted with potable water in the range of 100 to 200 times (1 part of the concentrate to 100 to 200 parts water), forming a stable emulsion suitable for treating porous substrates including but not limiting to masonry, concrete, bricks, wood, soil, fabric and paper.

[0013] The silane-based concentrate liquid is primarily composed of a water-insoluble alkyltrialkoxysilane with Cl to CIO alkyl groups on the silicon atom and a volatile natural oil, selected from the group consisting of eucalyptus oil, citrus peel oil, turpentine oil, pine oil, or other essential plant oils, is included to enhance the concentrate liquid’s dispersibility and efficacy. The formulation further comprises a water-soluble silane coupling agent, and a bonding polymer, selected from synthetic and natural resins, to improve durability and longevity. The formulation further comprises emulsifiers non-ionic, cationic, or anionic surfactants and pH-adjusting agents to ensure uniform dispersion and stability during dilution. These components synergistically contribute to superior nano -level dispersion in highly diluted water emulsions, making the concentrate liquid appropriate for application on a broad spectrum of inorganic materials and surfaces to impart durable and effective water repellence.

[0014] Beyond its water-repellent function, the concentrate liquid is designed for high dilution with potable water, forming dilute emulsion of the concentrate liquid, which provides antimicrobial protection by inhibiting the growth of algae, mold, microorganisms and a combination thereof on treated surfaces.

[0015] A distinctive method is provided to prepare the silane-based concentrate liquid of the present invention. The method comprises charging a reaction vessel with water-insoluble alkyltrialkoxysilane, and heating the water-insoluble alkyltrialkoxysilane, and adding a volatile natural oil to the heated alkyltrialkoxysilane and stirring to obtain a homogenous solution. The method further comprises adding an emulsifier to the homogeneous solution and then stirring and adding water-soluble coupling agent dropwise while maintaining temperature and stirring.The method further comprises adding a bonding polymer, stirring and adding pH adjusting agents and lowering the temperature and then processing the mixture through a high shear mixture to form a stable and homogenous concentrate liquid, which is diluted with potable water forming a highly diluted emulsion before application.DESCRIPTION OF ACCOMPANYING DRAWING:

[0016] The accompanying drawing constitute a part of the description and are used to provide further understanding of the present invention. Such accompanying drawing illustrates the embodiments of the present invention, which are used to describe the principles of the present invention together with the description.

[0017] Figure 1 illustrates the method for preparing the silane-based concentrate liquid for high-dilution waterproofing and substrate protection.DETAILED DESCRIPTION OF THE INVENTION

[0018] The compositions, formulations and methods discussed herein are merely illustrative of specific manners in which to make and use this invention and are not to be interpreted as limiting in scope. While the compositions and methods have been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the process without departing from the scope of the disclosure. It is understood that the compositions and methods are not limited to the embodiments set forth herein for purpose of exemplification.

[0019] In various embodiments of the present invention, a silane-based concentrate liquid and method for preparing the concentrate liquid is provided. The terms “silane-based concentrate liquid”, “concentrate liquid” and “liquid concentrate” are used interchangeably and generally refer to silane-based concentrate liquid for high dilution waterproofing and substrate protection.

[0020] The present invention provides a silane -based concentrate liquid specifically designed for high-dilution waterproofing and substrate protection, providing an environmentally friendly solution for treating porous materials including but not limiting toconcrete, masonry, wood, bricks, fabric, soil and paper. The dilute emulsion of silane-based concentrate liquid forming part of the proposed invention overcomes the challenges of longterm water repellence, antimicrobial protection, ignition susceptibility and environmental safety by offering a stable concentrate liquid that can be diluted with potable water in the ratio of 1 part concentrate to 100 to 200 parts potable water. For avoidance of doubt, the foregoing ratio refers to the dilution ratio used when mixing the silane-based concentrate liquid with potable water. For example, for every one litre of silane-based concentrate liquid, 100 to 200 litres of potable water would be used for dilution.

[0021] The following disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. While the present invention is detailed through multiple embodiments to ensure comprehensive disclosure and compliance with legal requirements, it is important to understand that the present invention is not restricted to these specific embodiments alone. The scope of this invention encompasses various forms of water repellents, particularly those based on organosilanes. The concentrate liquid of the present invention, when diluted with water, is adept at imparting water-repellent properties to a wide range of porous substrates and materials. Its application extends beyond, but is not limited to, materials such as concrete, bricks, plasters, mortar, wood, fabric, paper, and stone.

[0022] The concentrate liquid of the present invention, when diluted with water, penetrates the treated surface / substrates and seals the micro-channels that enable water seepage. This penetration by the organosilanes-based water repellents means that the repellent doesn’t form a noticeable layer on the treated surface / substrate. The effectiveness and durability of this water repellence are contingent on the strength of the bond formed between the water repellent’s micro molecules and the substrate, as well as the depth of penetration into the micro-channels. An effective extending medium forming part of the silane-based emulsion aids the reactive silicon molecules to space and spread out properly on the substrate, which enhances their ability to react and bind with the treated surface.

[0023] The composition of silane-based concentrate liquid comprises a volatile natural oil- modified water- insoluble silane coupling agent, water-soluble silane coupling agent, bonding polymer, an emulsifier, and pH-adjusting agent including carboxylic, mineral acids and alkalies in the form of a concentrate liquid. Upon dilution with potable water, thisconcentrate liquid transforms into a stable emulsion, that is then applied to the intended materials or surfaces using conventional techniques. The dilute emulsion of the concentrate liquid maintains a specific predetermined mole ratio of the volatile natural-oil modified alkyltrialkoxysilanes, water-soluble silane coupling agent, and the bonding polymer, thereby ensuring its effectiveness as a water-repellent.

[0024] The silane-based concentrate liquid of the current invention also differs from other water-soluble silanes created via glycol reactions, which further improves its effectiveness and molecular distancing for water repellence. The primary active ingredient in the silane-based concentrate liquid is a water-insoluble alkyltrialkoxysilane, which serves as the main water-repellent agent. This component penetrates deep into the micro -channels of porous substrates, forming stable chemical bonds with the substrate materials. The alkyltrialkoxy silane used in the proposed emulsion has alkyl groups with Cl to CIO alkyl groups on the silicon atom. This class of compounds is chosen for its ability to impart strong hydrophobic properties while also offering durability under various environmental conditions. In an embodiment, the water-insoluble alkyltri alkoxy silane are prior-treated and modified with volatile natural oils. Being water-insoluble, the volatile natural oils act as extender for water insoluble alkyltrialkoxysilane through molecular coating and ionic interaction, allowing for a lower volume of organosilanes to cover the larger area in highly dilute water-based emulsion. The presence of volatile natural oils helps in forming an emulsion.

[0025] The silane-based concentrate liquid further comprises of water-insoluble volatile natural oils, that act as an extender for organosilanes, allowing for a lower volume of organosilanes to cover the larger area in highly dilute water-based emulsion. The presence of volatile natural oils helps in forming an emulsion, which is a mixture where tiny droplets of oil are suspended in potable water. The volatile natural oil is selected from the group consisting of eucalyptus oil, citrus peel oil, turpentine oil, pine oil, and other essential oils derived from plants. These natural oils also act as dispersants, facilitating the uniform distribution of the silane compounds and reactive silicon molecules throughout the substrate. The use of natural oils as extending mediums contributes to the emulsion’s low VOC emissions and environmental friendliness.

[0026] The inclusion of volatile natural oils as an extender for alkyltrialkoxysilane leads to several beneficial results including: (1) The concentrate liquid is highly dilutable, allowing it to be mixed with potable water in the range of 100 to 200 times (1 part concentrate to 100 to 200 parts potable water). This makes the dilute emulsion economical and suitable for large-scale applications in construction, industrial and domestic settings; (2) Upon application, the dilute emulsion forms a hydrophobic layer within the treated substrate, preventing water ingress and moisture -related damage such as cracking, swelling, and corrosion; (3) The dilute emulsion also provides antimicrobial properties, preventing the growth of algae, mold, other microorganisms and a combination thereof, on treated surfaces. This feature makes it particularly useful for areas prone to moisture exposure and unrestricted growth of microorganisms, such as water reservoirs, damp walls, and tunnels; and (4) The dilute emulsion is formulated to be non-flammable and low in VOC.

[0027] The water-soluble silane coupling agent is selected from quaternary ammonium functional silane, including formulas like 2-methacryloxyethyldimethyl-3-trimethoxysilyl propyl ammonium chloride, Dimethyloctadecyl(3 -trimethoxy silylpropyl)ammonium chloride, and 3 -(trimethoxy silyl)propyldimethylhexadecyl ammonium chloride, amino silane, or other water-soluble silanes from formulas such as N-(2-aminoethyl)-3- aminopropyltrimethoxysilane, N-(aminoethylaminomethyl) phenyltrimethoxysilane, N-(2- aminoethyl)- 3-aminopropyltris (2-ethylhexoxy)-silane, 3 -aminopropyltrimethoxy silane, trimethoxysilylpropyl diethylenetriamine, and bis(2-hydroxyethyl)-3- aminopropyltrimethoxysilane. These coupling agents serve to improve adhesion, durability, and performance of concentrate liquid in various applications and prevents separation of the components.

[0028] The bonding polymers are selected from acrylic, polyurethane, as well as synthetic and natural resins. Synthetic resins include epoxy resins, polyester resins, phenolic resins, and polyurethane resins. Natural resins include pine resin, dammar resin, copal resin, and shellac. These polymers ensure that the water-repellent layer remains intact even after extended exposure to environmental conditions. The bonding polymer is included in the silane- based concentrate liquid to further enhance its durability and performance over time.

[0029] To maintain stability and prevent phase separation, the silane-based concentrate liquid is formulated with an emulsifier selected from non-ionic, cationic, or anionic surfactants. The non-ionic surfactants include alkylphenol ethoxylates, nonylphenol ethoxylates, fatty alcohol ethoxylates, and sorbitan esters. Cationic surfactants include quaternary ammonium compounds like cetyltrimethylammonium bromide (CTAB) and benzalkonium chloride. Anionic surfactants include sodium lauryl sulfate (SLS) and sodium dodecylbenzenesulfonate (SDBS). These surfactants (emulsifiers) help create a stable concentrate liquid that can be easily diluted with potable water and applied to various substrates.

[0030] The pH of the silane-based concentrate liquid is critical for maintaining the stability of the concentrate liquid during storage and application, and to create extended pH conditions for superior nano-level dispersion in highly dilute water emulsions, pH-adjusting agents are added in the formulation to ensure the emulsion remains stable in a highly diluted form. These pH adjusting agents are selected from organic acids such as formic acid, acetic acid, propionic acid, and butanoic acid, as well as mineral acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid. Alkalies such as triethanolamine, sodium hydroxide, or potassium hydroxide are also included to balance the pH and ensure long-term stability. The oil-extended alkyltrialkoxysilane and the water-soluble silane coupling agent should be present in the diluted aqueous solution in a mole ratio of about 0.3 :1 to about 3.0: 1, preferably between 1.0: 1.0 to about 1.5: 1.0, to achieve optimal water repellence.

[0031] In an embodiment of the present invention, the concentrate liquid may include at least about 0.05 weight percent of an oil-extended organosilicon compound. Further embodiments of the present invention may contain between 0.05 and about 80 weight percent of the oil-extended organosilicon compound. Additionally, certain embodiments may comprise between about 1 and 90 weight percent, preferably ranging from about 20 to 60 weight percent, of the oil-extended organosilicon compound.

[0032] Water, being an ideal medium to transport water-repellent molecules deep into the substrate's micro-channels, is essential for creating a stable emulsion. The composition of silane-based concentrate liquid not only simplifies handling but also offers environmental benefits like low VOCs emissions and reduced carbon footprint in diluted solutions (emulsions). Additionally, surfaces treated with diluted silane-based concentrate liquid gainextended protection against the microbial growth caused by algae, moss, other microorganisms and a combination thereof.

[0033] Figure 1 is a flow chart illustrating the method for preparing a silane-based concentrate liquid for high dilution water proofing and substrate protection in accordance with an embodiment of the present disclosure. At step 102, a reaction vessel is charged with 100 to 300 grams of a water-insoluble alkyltrialkoxysilane and is heated to a temperature between 50°C and 70°C. The purpose of heating the water- insoluble alkyltrialkoxysilane in the reaction vessel is to initiate condensation with other components, which is a pre-requisite for preparation of modified alkyltrialkoxysilane for further processing. In an embodiment, the water-insoluble alkyltrialkoxysilane is pre-treated and modified with natural oils before addition to the reaction vessel.

[0034] After the heating of water- insoluble alkyltrialkoxysilane, at step 104, 30-100 grams of a volatile natural oil is added to the reaction vessel, and the mixture is stirred for 5 to 15 minutes to obtain a homogeneous solution. An emulsifier, ranging from 5 to 30 grams, is then introduced into the homogeneous solution, and thereafter, the resultant mixture is further stirred for an additional 5 to 15 minutes. Stirring the resultant mixture at step 104 is critical as by stirring, the resultant mixture is optimized for stability, preventing separation thereby ensuring that the concentrate liquid performs consistently in its intended use, such as waterproofing or surface protection.

[0035] At step 106, 100 to 200 grams of a water-soluble silane coupling agent is added drop wise into the resultant mixture (of step 104) while maintaining the temperature between 50°C and 70°C, and continuous stirring is performed. Stirring at this step ensures that the individual components are mixed consistently.

[0036] At step 108, 10 to 50 grams of bonding polymer is added to the well-stirred mixture created at step 106. After adding the bonding polymer, the mixture is then stirred for another 10-20 minutes to ensure thorough mixing. The bonding polymer helps in improving the adhesion or bonding properties of the concentrate liquid, allowing it to better bond with the porous surfaces such as masonry, wood, fabric, paper or concrete. The concentration of thebonding polymer is determined to ensure the optimal level of adhesion, without affecting the stability or performance of the concentrate liquid.

[0037] At step 110, 0.5 to 5 grams of pH adjusting agents are introduced into the mixture for optimal stability of the concentrate liquid and dilute emulsion. After addition of the pH adjusting agents, the temperature of the mixture is lowered to between 40°C and 50°C. This temperature lowering and control prevents any thermal degradation of the mixture components and to promote long-term stability. The pH adjusting agents ensure that the mixture does not destabilize over time and the individual components do not break-apart or react with each other, and retain their intended properties.

[0038] At step 112, the mixture prepared at step 110, is processed through a high-shear mixer operating at 5000 to 6000 rpm for 5 to 20 minutes to form a stable and homogeneous concentrate liquid. The high shear mixing at this step aids in fine mixing and efficient particle size distribution, thereby creating a final concentrate liquid where components stay combined.

[0039] At step 114, the concentrate liquid created at step 112, is diluted by mixing 0.5% to 1.0% by weight of the concentrate liquid with potable water, resulting in a highly diluted solution (dilute emulsion) suitable for spraying, brushing, rolling, or dipping onto substrates such as concrete, bricks, wood, soil, and fabric. Using potable water for dilution of the concentrate liquid ensures that the dilute emulsion maintains its chemical stability and that there are no contaminants that might interfere with its effectiveness.

[0040] The application methods for the silane-based concentrate liquid of the present invention may vary depending on the need, level of dilution and the nature of the substrate. In an exemplary embodiment, the dilution ratio may range from 0.5 to 1 part of the concentrate to 100 parts of potable water. The resulting emulsion can then be applied to the surface using various application methods including spraying, brushing, rolling, brooming, splash-wiping, misting or dipping. It is to be noted that dilute emulsions of the concentrate liquid with water have wide range of applications and can be integrated into various manufacturing processes including but not limited to, the production of paper, fabric, concrete, bricks, stabilization of soil bases, and gypsum casting and domestic purposes.

[0041] The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope. By providing examples, the scope of the proposed invention should not be restricted and the examples are merely illustrative in nature. The variations or additional applications not explicitly covered in the examples are still within the scope of the proposed invention.

[0042] Example I: A glass reaction vessel was charged with 200 grams of methyltrimethoxysilane, and the reaction vessel was heated to 50°C. Slowly, 50 grams of eucalyptus oil was introduced into the reaction vessel with continuous stirring. The stirring was maintained for 10 minutes, resulting in a homogenous and clear solution. Subsequently, 20 grams of a non-ionic emulsifier, nonyl phenol ethoxylate (with 9.5 moles of EO), was added. The stirring was continued for an additional 10 minutes. The temperature was then elevated to 60°C, and 150 grams of Dimethyloctadecyl(3 -trimethoxy silylpropyl) ammonium chloride (42% solution in methanol) was added dropwise under constant stirring. Following this, 20 grams of powdered wood resin was introduced into the mixture, and stirring was continued for another 20 minutes. To this solution, 1 gram of acetic acid followed by 0.2 gram of phosphoric acid was added. Finally, the temperature of the mixture was reduced to 40°C. The final step involved passing the mixture through a stainless-steel high-shear mixer operating at 6000 rpm, resulting in a clear and stable solution (concentrate liquid).

[0043] Example II: Initially, 200 grams of ethyltriacetoxysilane was placed in a glass reaction vessel. The temperature of the contents of the reaction vessel was increased to 60°C. In a controlled manner, 50 grams of pine oil was added to the vessel while stirring. This stirring process was maintained for 10 minutes until a homogenous clear solution was formed. Next, 8 grams of a quaternary ammonium emulsifier, PSEM-SS-ABT, was introduced to the mixture, and stirring was continued for another 10 minutes. Subsequently, the temperature was lowered to 50°C. Then, 150 grams of Dimethyloctadecyl (3-trimethoxysilylpropyl) ammonium chloride (42% solution in methanol) was added gradually under constant stirring, and the methanol was removed via an aspirator. After this, 50 grams of Synapol B-10 acrylic resin was incorporated into the solution, with stirring persisting for 20 minutes. Following the resin addition, 5 grams of acetic acid and then 0.2 gram of phosphoric acid were added to the mixture. The final procedure involved cooling the mixture to 40°C and processing it through a stainless -steel high- shear mixer at 6000 rpm to yield a clear and stable solution (concentrate liquid).

[0044] Example III: A glass reaction vessel was prepared with 150 grams of ethyltrimethoxysilane, and the temperature of the reaction vessel was adjusted to 60°C. Then, 100 grams of pine oil was gradually added with continuous stirring. After stirring for 10 minutes, a homogenous clear solution was achieved. Subsequently, 8 grams of the quaternary ammonium emulsifier PSEM-SS-ABT was introduced into the solution, and the mixture was stirred for an additional 10 minutes. The temperature was then lowered to 50°C. At this point, 150 grams of trimethoxy silylpropyldiethylenetriamine was incorporated dropwise, with ongoing stirring to ensure even distribution. Next, 50 grams of Sripol CASB-80 polyester resin was added to the vessel, and stirring was maintained for 20 minutes to ensure thorough mixing. Afterwards, 3 grams of acrylic acid was added to the mixture, followed by 0.2 grams of hydrochloric acid. To finalize the process, the mixture's temperature was reduced to 40°C. The solution was then processed through a stainless -steel high shear mixer operating at 6000 rpm to obtain a clear and stable solution (concentrate liquid).

[0045] Example IV: 200 grams of triethoxypropylsilane was introduced into a glass reaction vessel. The contents were then heated to a temperature of 70°C. With steady stirring, 100 grams of pine oil was added slowly into the vessel. This stirring was sustained for 10 minutes until a homogenous and clear solution was formed. Following this, 5 grams of the quaternary ammonium emulsifier PSEM-SS-ABT was incorporated into the solution, with the stirring process continuing for an additional 10 minutes. Subsequently, the temperature was decreased to 60°C. Under continuous stirring, 200 grams of 3 -aminopropyltriethoxy silane was added to the mixture in a dropwise fashion. Next, 50 grams of Sripol CASB-80 polyester resin was added, and the solution was stirred for a further 20 minutes to ensure full integration of all ingredients. Thereafter, 3 grams of acrylic acid followed by 0.1 grams of hydrochloric acid were introduced to the reaction mixture. The final step involved cooling the mixture down to 40°C and then processing it through a stainless-steel high-shear mixer set at 6000 rpm. This resulted in a clear and stable solution (concentrate liquid).

[0046] Example V: 300 grams of triethoxypropylsilane was placed in a glass reaction vessel. The vessel's contents were heated to 70°C. Gradually, 100 grams of turpentine oil was added while the mixture was continuously stirred. This stirring was maintained for 10 minutes until the solution became homogenous and clear. Five grams of a non-ionic emulsifier, specifically nonyl phenol ethoxylate with an ethoxylation degree of 9.5 moles, were thenintroduced into the solution. Stirring was prolonged for another 10 minutes to ensure proper mixing. Afterwards, the temperature was decreased to 60°C, and 200 grams of trimethoxysilylpropyldiethylenetriamine were added to the vessel dropwise with steady stirring. Following the addition of the silane, 40 grams of Sripol CASB-80 polyester resin were added to the reaction mixture, with stirring continuing for a further 20 minutes. The reaction was then adjusted with the addition of 6 grams of acetic acid and subsequently 0.05 grams of sulphuric acid. To complete the process, the temperature of the resultant mixture was lowered to 40°C. The final step was to pass the mixture through a stainless -steel high-shear mixer operating at 6000 rpm to produce a clear solution.

[0047] Example VI: 200 grams of triethoxypropylsilane was introduced into a glass reaction vessel. The contents were then heated to a temperature of 70°C. With steady stirring, 50 grams of turpentine oil was added slowly into the vessel. This stirring was sustained for 10 minutes until a homogenous and clear solution was formed. Following this, 15 grams of the quaternary ammonium emulsifier PSEM-SS-ABT was incorporated into the solution, with the stirring process continuing for an additional 10 minutes. Subsequently, the temperature was decreased to 50°C. Under continuous stirring, 200 grams of 3 -aminopropyltriethoxy silane was added to the mixture in a dropwise fashion. Next the temperature was increased to 70°C, 50 grams of powdered pine resin was added, and the solution was stirred for a further 20 minutes to ensure full integration of all ingredients. Thereafter, 5 grams of triethanolamine followed by 0.05 grams of potassium hydroxide were introduced to the reaction mixture. The final step involved cooling the mixture down to 40°C and then processing it through a stainless -steel high-shear mixer set at 6000 rpm. This resulted in a clear and stable solution (concentrate liquid).

[0048] Example VII: Concrete samples measuring 76mm in diameter were prepared using a standard M20 concrete mix and were air-dried for 7 days. Post-drying, the samples were abraded with 1000-grit emery paper and subsequently cleaned with a cotton cloth. They were then subjected to a drying process at 110°C for 2 hours, followed by cooling in a desiccator for testing purposes. To evaluate the water absorption of both untreated and treated samples, an untreated sample was designated as the control. Ten separate dilutions of the concentrate liquids were prepared, dissolving 0.5 and 1 percent of the concentrate liquids from Examples I to VI in potable water. Each concrete sample was immersed in one of the prepareddilute emulsions (solutions) for thirty seconds. This step was repeated with all dilutions. Post immersion, the samples were air-dried for 24 hours and subsequently oven-dried at 110°C for 1 hour before being cooled in a desiccator. Both the control and treated samples underwent immersion in tap water for one hour. After removal, they were dried using non-disintegrating5 absorbent paper tissue and then weighed. The percentage of water absorption was calculated using the formula:= (weight after water immersion x 100) / weight of the dry sample.

[0049] The results of evaluations of Example VII were recorded and presented in Table- 1. Table- 1 depicts readings of percentage of water absorption by concrete samples treated 10 with dilute emulsion of silane-based concentrate liquid prepared based on the step wise process described in exemplary embodiments (Example I to Example VI). It may be apparent to a person skilled in the art that the absorption percentage of the treated surface compared to the control has reduced significantly, thereby illustrating water repellant nature of the dilute emulsion of the concentrate liquid.15 Table-

[0050] Example VIII: Square samples of red bricks, each with a dimension of 76mm, were extracted from full-sized bricks using a stone cutter. The brick samples were then smoothened with 1000-grit emery paper and cleaned using a cotton cloth. The prepared samples were dried at a temperature of 110°C for a duration of 2 hours, then cooled in a 20 desiccator prior to testing. An untreated brick sample was retained as a control for comparison to assess water absorption. In total, ten different dilutions of the inventive emulsion were prepared by dissolving 0.5 and 1 percent of the concentrate derived from Examples I to VI in potable water. Each brick sample underwent a thirty-second immersion in one of the dilute solutions. This procedure was replicated with all dilutions. Post-treatment, the brick samples 25 were left to air dry for 24 hours, followed by additional drying in an oven set at 110°C for 1 hour, before being cooled in a desiccator. Subsequently, both the control and treated bricksamples were submerged in tap water for one hour. Upon removal, they were patted dry with non-disintegrating absorbent paper tissue and weighed. The percentage of water absorption was determined using the formula: (weight after water immersion x 100) / weight of the dry sample. The results were then organized and documented in the Table-2 (table below) for5 analysis. Table-2 shows readings of percentage of water absorption by brick samples treated with silane-based emulsions prepared, based on the step wise process described in exemplary embodiments (Example I to Example VI). It may be apparent to a person skilled in the art that the absorption percentage of the treated surface compared to the control has reduced significantly, thereby illustrating water repellant nature of the silane-based emulsion.10 Table-2

[0051] Example IX: Sandy soil samples, each with a diameter of 76mm, were prepared by adding optimum moisture content with 0.5, and 1.0 percent solutions of the concentrate from Examples I to VI in potable water. The moistened soil was then compacted using a 10 Kg weight press and allowed to air dry for a duration of 7 days. Post air-drying, the samples were 15 subjected to further drying at a temperature of 110°C for 2 hours, followed by cooling in a desiccator before testing. For the water absorption test, the control soil sample, along with the treated samples, were immersed in tap water for two minutes. After removal from the water, each sample was blotted with non-disintegrating absorbent paper tissue and immediately weighed. The percentage of water absorption was then calculated using the formula: (weight 20 after water immersion x 100) / weight of the dry sample. The data was compiled and tabulated in Table-3. Table-3 shows readings of percentage of water absorption by soil samples treated with silane-based emulsions prepared, based on the step wise process described in exemplary embodiments (Example I to Example VI). It may be apparent to a person skilled in the art that the absorption percentage of the treated surface compared to the control has reduced 25 significantly, thereby illustrating water repellant nature of the silane-based emulsion.Table-3

[0052] Example X: Rectangular tissue paper samples measuring 300 mm were prepared by cutting commercial tissue paper and folding it twice. These samples were oven- dried at 100°C for 15 minutes, subsequently cooled in a desiccator, and then set aside for5 testing. To assess water absorption, an untreated tissue paper sample served as the control. For the experiment, ten dilutions of the current invention were prepared by dissolving 0.5 and 1 percent of the concentrate from Examples I to VI in potable water. Each tissue paper sample was submerged in a dilute solution for thirty seconds, repeating the process across all dilutions. Post-immersion, the samples were laid on an inclined, polished glass surface to shed the excess10 solution and then left to air dry for 24 hours. A second drying phase followed in an oven at 100°C for 15 minutes, after which the samples were cooled in a desiccator. Both the control and the treated tissue paper samples were dipped in tap water for two minutes. They were then removed, gently dried using the sandwich method with two layers of non -disintegrating absorbent paper tissue and weighed. The percentage of water absorption was determined with15 the formula: (weight after water immersion x 100) / weight of the dry sample. The results were calculated and tabulated in Table-4. Table-4 shows readings of percentage of water absorption by tissue paper samples treated with silane-based emulsions prepared on the basis of step wise process described in exemplary embodiments (Example I to Example VI). It may be apparent to a person skilled in the art that the absorption percentage of the treated tissue paper compared20 to the control has reduced significantly, thereby illustrating water repellant nature of the silane- based emulsion.Tabled

[0053] Basis the exemplary embodiments and the results obtained and presented in Table 1 to 4, it may be apparent to a person skilled in the art that the silane-based concentrate liquid disclosed in the present invention, are designed to provide a high degree of water repellence to a wide array of materials such as masonry, soil, paper, fiber, and cellulosic surfaces. A critical aspect of this invention, which is considered important but not limiting, is the molecular behavior of silicon upon the drying of the aqueous dilution. The oil assists in the deeper penetration of silicon into the micro-pits and capillaries of substrates, where it forms stable chemical bonds with the inorganic material. The bonding polymer further assist in plugging of micro-pits and capillaries. This interaction ensures the longevity of the water- repellent layer, marking a significant improvement over existing silane-based waterproofing technologies. This approach differentiates the present invention from the prior art, offering enhanced performance and application benefits, which is also apparent from the results stated in Table- 1 to 4.

[0054] The silane-based concentrate liquid provides for an effective solution for structures and locations where water-repellant characteristic is absolutely essential including buildings, concrete structures, highways, railways, dams, canals, water reservoirs, subgrade soils, soil slopes, bridge decks, spillways, tunnels, rainwater harvesting pits, and waterproofing paper and fabric. The building industry, which frequently utilizes porous materials with mineral components such as bricks, plaster, cement blocks, natural stones, and reinforced concrete, can particularly benefit from these silane-based concentrate liquids.

[0055] While the present invention has been shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

We claim:

1. A silane-based concentrate liquid for high-dilution waterproofing and substrate protection, the concentrate liquid comprising: a water- insoluble alkyltrialkoxy silane selected from alkyltrialkoxy silanes with Cl to CIO alkyl groups on the silicon atom; a volatile natural oil selected from the group consisting of eucalyptus oil, citrus peel oil, turpentine oil, pine oil, and other essential plant oils; a water-soluble silane coupling agent; a bonding polymer selected from the group consisting of acrylic, polyurethane, synthetic and natural resins; an emulsifier selected from non-ionic, cationic, or anionic surfactants; and a pH adjusting agent to optimize stability and enhance the uniform dispersion of components; wherein the concentrate liquid is designed for high dilution with potable water to form a stable emulsion for the treatment of porous substrates; and wherein the diluted emulsion provides antimicrobial protection by inhibiting the growth of algae, mold, microorganisms or a combination thereof, on the treated surfaces.

2. The concentrate liquid as claimed in claim 1, wherein the water-soluble silane coupling agent is selected from the group consisting of: quaternary ammonium functional silanes, including: 2-methacryloxyethyldimethyl-3- trimethoxysilylpropylammonium chloride, Dimethyloctadecyl (3-trimethoxysilylpropyl) ammonium chloride, and 3-(trimethoxysilyl) propyldimethylhexadecyl ammonium chloride; andamino silanes, including: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N- (aminoethylaminomethyl) phenyltrimethoxy silane, N-(2-aminoethyl)-3- aminopropyltris(2-ethylhexoxy)-silane, 3-aminopropyltrimethoxysilane,Trimethoxysilylpropyldiethylenetriamine, and bis(2-hydroxyethyl)-3- aminopropyltrimethoxysilane.

3. The concentrate liquid as claimed in claim 1, wherein the synthetic resin in bonding polymer is selected from the group consisting of epoxy resins, polyester resins, phenolic resins, and polyurethane resins; and the natural resins are selected from the group of pine resin, dammar resin, copal resin, and shellac.

4. The concentrate liquid as claimed in claim 1, wherein the emulsifier is selected from the group consisting of: non-ionic surfactants, including: alkylphenol ethoxylates, nonylphenol ethoxylates, fatty alcohol ethoxylates, and sorbitan esters; cationic surfactants, including: quaternary ammonium compounds such as cetyltrimethylammonium bromide (CTAB), dimethyldioctadecylammonium chloride, and benzalkonium chloride; and anionic surfactants, including: sodium lauryl sulfate (SLS), sodium dodecylbenzenesulfonate (SDBS) and alkyl sulfates.

5. The concentrate liquid as claimed in claim 1, wherein the pH-adjusting agent is selected from the group consisting of: organic acids, including: formic acid, acetic acid, propionic acid, and butanoic acid; mineral acids, including: sulphuric acid, hydrochloric acid, phosphoric acid, and nitric acid; andalkalies, including: triethanolamine, sodium hydroxide, and potassium hydroxide.

6. The concentrate liquid as claimed in claim 1, wherein the mole ratio of the alkyltrialkoxy silane to the water-soluble silane coupling agent ranges from 0.3: 1 to 3.0: 1, preferably between 1.0: 1.0 to 1.5: 1.0, in the dilute emulsion.

7. The concentrate liquid as claimed in claim 1, wherein the water-insoluble alkyltrialkoxy silane is modified with volatile natural oils to enhance efficacy of the concentrate liquid.

8. The concentrate liquid as claimed in claim 1, wherein the dilute emulsion of the concentrate liquid is non-flammable, has low VOC emissions, and is environmentally friendly, making it suitable for use in eco-sensitive environments.

9. A method for preparing a silane-based concentrate liquid for high-dilution waterproofing and substrate protection, comprising the steps of: charging a reaction vessel with 100 to 300 grams of a water-insoluble alkyltrialkoxysilane, and heating the water-insoluble alkyltrialkoxy silane to a temperature between 50°C to 70°C; adding 30 to 100 grams of a volatile natural oil to the heated alkyltrialkoxysilane, and stirring for 5 to 15 minutes to obtain a homogeneous solution; adding 5 to 30 grams of an emulsifier to the homogeneous solution, and stirring mixture of the homogenous solution with the emulsifier for an additional 5 to 15 minutes; adding 100 to 200 grams of a water-soluble silane coupling agent dropwise into the mixture while maintaining a temperature between 50°C to 70°C and stirring continuously; incorporating 10 to 50 grams of a bonding polymer to the mixture, and stirring for 10 to 20 minutes to ensure thorough mixing;introducing 0.5 to 5 grams of pH adjusting agents and lowering the temperature of the mixture to 40°C to 50°C; processing the mixture through a high-shear mixer operating at 5000 to 6000 rpm for 5 to 20 minutes to form a stable and homogeneous concentrate liquid; diluting the concentrate liquid for application by mixing 0.5% to 1.0% by weight of the concentrate liquid with potable water, forming a dilute emulsion; wherein the dilute emulsion is used for the treatment of porous substrates; and wherein the dilute emulsion provides antimicrobial protection by inhibiting the growth of algae, mold, other microorganisms or a combination thereof on the treated surfaces.

10. The method as claimed in claim 9, wherein the water-insoluble alkyltrialkoxysilane is premodified with volatile natural oils to enhance efficacy of the concentrate liquid.

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