ITVI20120124A1 - FORMULATION TO FACILITATE THE REMOVAL OF ICE FROM THE VEHICLE WINDSCREEN AND PROCEDURE FOR ITS PRODUCTION - Google Patents

Description

FORMULATION TO FACILITATE THE REMOVAL OF ICE FROM THE WINDSHIELD OF MOTOR VEHICLES AND PROCEDURE FOR ITS PRODUCTION.

DESCRIPTION

Technical field

The invention relates to a formulation that facilitates the removal of ice, particularly for automotive glass, which includes particles of silica, alternatively of titania or alumina, a polydiorganosiloxane and / or its hydrolyzates or condensates and a cross-linking agent. A process for producing such a formulation is also proposed. Once the formulation has been applied on various types of surfaces, preferably glass, in the presence of water or humidity a film is obtained which, in the presence of high humidity at temperatures below 0 ° C, facilitates the removal of the ice formed on the glass. .

State of the art

Numerous formulations are known which are suitable for promoting the protection of motor vehicle glass from atmospheric agents, such as for example anti-ice formulations.

It is well known that condensation forms on the glass of a vehicle (in particular the windscreen) parked outside, at a temperature below 0 ° C and with a high percentage of humidity (over 60%), which in short it turns to ice.

A plastic “scraper” is commonly used for instant ice removal. On the market there are also anti-ice products contained in spray cans that must be used frequently to melt the ice formed on the windshield. The known art also offers as an alternative to the use of the "scraper" and / or spray cans the application of chemical compositions with an anti-ice effect on the glass, giving rise to a non-stick film that avoids the accumulation of water and consequently the formation of ice.

The anti-ice formulations present in the known art generally comprise silica particles and a polymeric binding agent.

Two European documents, EP 0 555 879 A1 and EP 0 274 428 A2, describe coatings comprising organosilanes, their hydrolysates and condensates, which however always also contain vinyl resins which often give problems from an ecological point of view.

The US document US 4,774,122 describes a formulation which, when applied to surfaces, avoids the adhesion of ice.

The formulation contains a filler (for example, a silica), α, ωdihydroxy-diorganosiloxane (for example, dimethylsiloxane), plasticizers and cross-linking substances (for example, RySiX4-y, in which y can be 1 and R an alkyl and in which X is able to react with the silanol groups of the siloxane).

However, the products available on the market once applied to the glass do not give a very durable anti-ice protection. Frequent applications of the product are required, often days or weeks apart.

Presentation of the invention

The main object of the present invention is to overcome the aforementioned drawbacks by proposing alternatives to the known anti-ice formulations which, in particular, have a high durability once applied to the glass. A further purpose of the invention is to propose a method for producing such a formulation.

The objects mentioned above and others which will be better highlighted hereinafter are achieved by a formulation set out in the first claim.

The formulation according to the invention applied on glasses where it subsequently forms a transparent film, gives them non-stick characteristics and favors the formation of micro-droplets which, once frozen, are easily removable, as well as considerable protection at temperatures below 0 ° C with humidity more than 60%.

The synergy between the components gives the product marked sealing qualities. The methods of production of the formulation, described below, optimize these qualities.

A film deriving from the formulation according to the invention forms a robust, stable and non-stick curtain which, like the de-icing products available on the market, does not prevent condensation or the formation of dew thanks to the very small contact angle, but which favors the formation of micro-droplets separated from each other which, once frozen, are easily eliminated by operating the wiper blades.

The anti-ice formulation according to the invention gives the treated surface an excellent and lasting dripping effect towards aqueous liquids, a remarkable resistance to wear and abrasion by aggressive elements, as well as protection from atmospheric agents, with a minimum effect of about 6 months in the case of application to glass of cars and the like, and greater in the case of static applications (windows, balconies, greenhouses, etc.).

In addition, a sealing effect is obtained even on the smallest roughness of the surfaces on which the treatment was carried out, giving resistance to microbial contamination and dirt and ensuring almost perfect hygienic conditions of the treated surfaces.

Furthermore, advantageously, the formulation allows to obtain an absolutely transparent coating and therefore invisible to the human eye, giving the coated product an unaltered appearance compared to that of the uncoated product.

The resulting film is waterproof and water-repellent, but at the same time able to allow transpiration, which is important if the film is used on materials that must have breathable characteristics, for example in the food sector.

The formulation according to the invention is easily manufactured, applicable with reduced drying times, has low application costs, considerable efficiency in terms of yield as minimum quantities of product are sufficient to obtain these results, increases visibility in the case of glass of automobiles and thus allows a more limited use of windshield wipers. Anti-stain, anti-dust, anti-sun rays and easy removal of ice effects are observed up to temperatures of about -26 ° C.

Particularly advantageous are formulations in which the particles are silica particles.

The silica, titania or alumina particles (or mixtures thereof) can be added in ready-made form to the formulation, for example in the form of commercially available silica nanoparticles, or they are produced in situ in the formulation, in the case of silica, preferably according to steps a) -d) of the process according to the invention. Particles with dimensions in the range of nanoparticles are preferable.

The formulation forms, in the presence of water or humidity, a cross-linked film also incorporating the particles of silica, alumina or titania which can be modified on the surface by reacting with the other chain or cross-linking compounds present in the formulation. The best results are obtained with polydimethylsiloxane.

Advantageously, the polydimethylsiloxane is hydroxy-terminated. The crosslinking agent is preferably dodecyl-triethoxysilane.

In a preferred variant of the invention, the polydiorganosiloxane is a hydroxy-terminated polydimethylsiloxane with a molecular weight of about 4200 / - 400 g / mol. Preferably, the molecular weight is approx. 4200 g / mol.

In an advantageous variant of the invention, the formulation is an alcoholic solution. The best results were obtained with an isopropanol solution.

Advantageously, the molar ratio between polydimethylsiloxane and (RO) 3SiR 'is about 1: 5.5 - 1: 6.5, preferably 1: 5, 7-1: 6, more preferably 1: 5.85. This ratio allows for the creation of a film on the glass that is sufficiently thin, stable and sealant.

The molar ratio between polydimethylsiloxane and silica, considering single units of "Si02" (or the starting molecule, for example Si (OEt) 4 in the case of in situ production) is advantageously 1: 18-22, more preferably 1: 19.5 -20, even more preferably about 1: 19.7. This is true, mutatis mutandis, also for Ti020 ΑΙ2θ3 particles.

The ratios listed gave the best product performance.

The performance of the formulation can be further optimized by adding at least one complexing agent, preferably selected from Na4EDTA, 1-hydroxyethane-1, 1-diphosphonic acid (HEDP), and the sodium salt of nitrile triacetic acid (NTA). Preferably, a combination of Na4EDTA and 1-hydroxyethane-1,1-diphosphonic acid (HEDP) is added.

Another aspect of the invention concerns a process for the production of a formulation according to the invention which includes the following steps:

(a) mixing of Si (OR) 4, wherein R = H, alkyl, Ac, preferably Et, in an alcohol, preferably heated isopropanol:

(b) addition of a basic aqueous solution, preferably of NaOH;

(c) optionally addition of at least one complexing agent, preferably selected from Na4-EDTA, 1-hydroxyethane-1, 1-diphosphonic acid (HEDP) and the sodium salt of nitrile triacetic acid (NTA); (d) pH adjustment with the help of an acid, preferably HCI, to about 4.0-5.0, preferably 4.5;

(e) addition of a polydiorganosiloxane ending in hydrolyzable groups able to react in condensation reactions, preferably polydimethylsiloxane, and a compound having the formula R'SiX3, in which X are independently hydrolyzable groups and able to react in condensation reactions, in wherein preferably X = hydroxy, alkoxy, acyloxy, more preferably ethoxy, and R 'is an alkyl with at least 10 carbon atoms, preferably 11-15 carbon atoms, more preferably 12 carbon atoms.

Advantageously, the polydiorganosiloxane is a hydroxy-terminated polydimethylsiloxane with a molecular weight of about 4200 / - 400 g / mol, preferably with a molecular weight of about 4200 g / mol.

Furthermore, advantageously, the molar ratio between polydimethylsiloxane and R'SiX3 is about 1: 5.5 - 1: 6.5, preferably 1: 5, 7-1: 6, more preferably 1: 5, 85.

The characteristics listed above for the formulation according to the invention also apply to the process for its production. A further important aspect of the invention concerns a film that is obtained from the application, respectively of the formulation according to the invention or of the product obtained with the process according to the invention, on the glass in the presence of water or humidity. The application of the formulation on glass in the presence of water or humidity results in the condensation of the polymer chains and the cross-linking agent, also incorporating the silica (or alumina or titania) particles, which thus form a transparent sealing film with the desired characteristics for the easy removal of ice. Another aspect of the invention concerns the use of the formulation according to the invention to facilitate the removal of ice from surfaces, in particular from glass, ceramics, plexiglass and stainless steel, more preferably from the windshield of motor vehicles.

A further aspect of the invention concerns the use of the formulation according to the invention to give the surfaces sealing and / or anti-bacterial properties, in particular in the food and / or health sector.

The aim has been achieved of providing a formulation which favors the removal of ice as a coating for surfaces, in particular for glass, and which also gives the latter sealing, water-repellent and anti-bacterial characteristics, as well as considerable protection from internal humidity and / or external, from sunlight and atmospheric agents.

The duration of the film with these characteristics is approximately one winter season.

Variants of the invention are the subject of dependent claims. The description of preferred examples of execution of the formulation and process according to the invention is given by way of non-limiting example.

Description of the preferred example of execution

The process for the production of a liter of product includes the following steps.

A 2% solution of NaOH in water, a 1% solution of EDTA-4Na in water, a 2% solution of HCI in water and a solution of 1-hydroxyethane-1, 1-diphosphonic acid (HEDP ) in 1% water. Unless otherwise specified, percentage indications are indications referring to weight.

800 ml of isopropanol are heated to 60 ° C. 10 ml of Si (OEt) 4 are mixed with the heated isopropanol and the solution is kept for 10 minutes under stirring.

10 ml of the previously prepared NaOH solution are added and it is left to act for 10 minutes. 20 ml of the EDTA solution and 5 ml of the 1-hydroxyethane-1,1-diphosphonic acid (HEDP) solution mentioned above are added.

With the hydrochloric acid prepared before, the pH is brought to a value of 4.5. The mixture is kept under stirring until it reaches a temperature of about 30 ° C. 10 ml of hydroxy-terminated polydimethylsiloxane with a molecular weight of about 4200 are added. Subsequently, 5 ml of dodecyl-triethoxysilane are added and the whole is kept under stirring for 30 minutes.

To apply the formulation on the surfaces to be treated, usually glass, for example, proceed as follows.

Preliminarily, the surface to be treated is made clean, in particular free from grease and dry, for example by using a cloth soaked in a suitable detergent or alcohol. Then the product is distributed (about 80 ml) poured by gravity on the glass with a cloth or sponge evenly on the surface. Finally, we recommend the use of a glass polishing cloth together with gloves to prevent the lipid content of the skin of the hands from compromising the protective treatment.

For optimal treatment, the temperature of the atmosphere and of the glass is between 5 ° C and 20 ° C.

Possibly it is not necessary to carry out the treatment with beating sun on the glass, in the presence of hot glass (> 20 ° C) or below 7 ° C. The sealing effect conferred by the product will be obtained after about 60 minutes, but it is advisable not to wet the surface before 24 hours after the end of the treatment.

The verification of the perfect sealing action can be carried out by depositing a few drops of water on the glass, which should immediately slide off an inclined wall while on a flat surface the water will remain deposited in drops.

The use of the formulation according to the invention on car windows allows to obtain a long-lasting brilliance, not to use common detergents for periodic cleaning of the windows, to use the windscreen wipers in a more limited and reduced way and to increase visibility. glass even in the presence of pouring rain and with the car stationary.

Furthermore, the inventors have observed that the use of the product in the food industries, in particular on glass, ceramic, plexiglass and stainless steel surfaces, allows the formation of a barrier that prevents microorganisms from penetrating, guaranteeing optimal hygienic conditions.

It is clear that the formulation according to the invention can be modified in a manner known to the expert in the technical sector without thereby departing from the scope of protection.

In particular, it is evident that, in addition to the application illustrated here in detail for illustrative but not limiting purposes, the skilled in the art will easily identify other examples of possible application surfaces (such as mirrors, crystals, showers, swimming pool linings, changing rooms, walls of food industries, etc.) as well as other sectors of use (such as commercial and industrial catering, construction and renovation companies, ceramics, glass windows in general, etc.).

The film is also stable to sudden changes in temperature and resistant to high and low temperatures. The silica particles are suspended in the formulation, they do not float and do not precipitate thanks to the interaction of the high surface with the solvent and the other components of the mixture.

Tests carried out on untreated glass show that, both on a winter day with temperatures below 0 ° C and with humidity above 60% and following laboratory tests with temperatures below 0 ° C, by vaporizing water on the glass of a car (assuming fog or humidity> 60%), the same rests on the glass evenly and in a short time the water droplets resting on the glass attract each other forming a single layer. Within a couple of hours, ice forms which, with the passage of time, in the presence of other humidity, thickens more and more until it becomes a single block that is difficult to remove.

By carrying out the same tests on a glass of the windshield of a vehicle previously treated with the formulation object of the present invention, a myriad of micro-droplets detached from each other are formed.

The subsequent freezing phase causes the formation not of ice, but of a more or less powdery frost that can be easily removed with the simple action of the wipers (from two to eight times depending on the temperature and intensity of humidity). The lower the percentage of humidity, the fewer brush strokes needed to remove the frost.

The particular composition of the formulation is invisible to the naked eye and, following the sealing action of the glass micropores, gives the treated surface a better resistance to wear and abrasion, making it more slippery and improving the performance of the wiper blades, increasing their duration. . The vehicle user will carry out the application at the beginning of the winter season and will be sure that the product will be active until the end of the cold season.

In the executive phase, further modifications or executive variants and not described may be made to the formulation, procedure, film and uses of the invention. Should such modifications or variations fall within the scope of the following claims, they must all be considered protected by this patent.

Claims (10)

CLAIMS 1) Formulation to facilitate the removal of ice from the windshield of motor vehicles, comprising particles of silica, alumina or titania, preferably particles of silica, a polydiorganosiloxane ending in hydrolyzable groups and suitable to react in condensation reactions, preferably polydimethylsiloxane, and / or its hydrolyzates or condensates and a cross-linking agent based on R'Si (X) 3 in which X are independently hydrolyzable groups and suitable to react in condensation reactions, and / or its hydrolyzates or condensates, in which preferably X = hydroxy, alkoxy, acyloxy, more preferably ethoxy, and R 'is an alkyl with at least 10 carbon atoms, preferably 11-14 carbon atoms, more preferably 12 carbon atoms. 2) Formulation according to claim 1) characterized in that the polydiorganosiloxane is a hydroxy terminated polydimethylsiloxane with a molecular weight of about 4200 / - 400 g / mol, preferably with a molecular weight of about 4200 g / mol. 3) Formulation according to one of claims 1) or 2) characterized in that the formulation is an alcoholic solution, preferably an isopropanol solution. 4) Formulation according to any one of the preceding claims characterized in that the molar ratio between polydimethylsiloxane and (RO) 3SiR 'is about 1: 5.5 - 1: 6.5, preferably 1: 5, 7-1: 6, plus preferably 1: 5.85. 5) Formulation according to any one of the preceding claims characterized in that it also comprises at least one complexing agent, preferably selected from Na4EDTA, 1-hydroxyethane-1, 1-diphosphonic acid (HEDP), and the sodium salt of nitrile triacetic acid (NTA) . 6) Process for the production of a formulation to facilitate the removal of ice from the windshield of motor vehicles comprising the following steps: (a) mixing Si (OR) 4lin which R = H, alkyl, Ac, preferably Et, in an alcohol, preferably heated isopropanol; (b) addition of a basic aqueous solution, preferably of NaOH; (c) optionally addition of at least one complexing agent, preferably selected from Na4-EDTA, 1-hydroxyethane-1, 1-diphosphonic acid (HEDP) and the sodium salt of nitrile triacetic acid (NTA); (d) pH adjustment with the help of an acid, preferably HCI, to approx. 4.0-5.0, preferably 4.5; (e) addition of a polydiorganosiloxane ending in hydrolyzable groups able to react in condensation reactions, preferably polydimethylsiloxane, and a compound having the formula R'SiX3 in which X are independently hydrolyzable groups and able to react in condensation reactions, in which preferably X = hydroxy, alkoxy, acyloxy, more preferably ethoxy, and R 'is an alkyl with at least 10 carbon atoms, preferably 11-15 carbon atoms, more preferably 12 carbon atoms. 7) Process according to claim 6) characterized in that the polydiorganosiloxane is a hydroxy-terminated polydimethylsiloxane with a molecular weight of about 4200 / - 400 g / mol, preferably with a molecular weight of about 4200 g / mol. 8) Process according to any one of claims 6) or 7) characterized in that the molar ratio between polydimethylsiloxane and R'SiX3 is about 1: 5.5 - 1: 6.5, preferably 1: 5, 7-1: 6 , more preferably 1: 5.85. 9) Film obtained by applying the formulation according to any one of claims 1) to 5) or the product obtained according to the process according to any of the claims 6) to 8) on glass in the presence of water or humidity. 10) Use of the formulation according to any one of claims 1) to 5) or of the product obtained according to the process according to any one of claims 6) to 8) to facilitate the removal of ice from surfaces, in particular from glass, ceramics, plexiglass and stainless steel, more preferably from automotive windshields. 1 1) Use of the formulation according to any one of claims 1) to 5) or of the product obtained according to the process according to any one of claims 6) to 8) to impart sealing and / or antibacterial properties to surfaces, in particular in the food and / or health sector.