WO2023136793A1

WO2023136793A1 - A water based mirror

Info

Publication number: WO2023136793A1
Application number: PCT/TR2022/051239
Authority: WO
Inventors: Rustem KHAFISOV; Halide Gulsah KAHRAMAN; Ipek Nuran BAYRAM; Senem Kadriye HELVACI OZSOY; Aytac OZTURK
Original assignee: Turkiye Sise Ve Cam Fabrikalari Anonim Sirketi
Priority date: 2022-01-12
Filing date: 2022-11-03
Publication date: 2023-07-20

Abstract

The present invention relates to a water-based mirror (1) with increased durability which is used for decorative purposes, especially in architectural applications, furniture, building facades, interior decoration, showcases, medical industry, automotive industry, and for creating the reflection of objects by reflecting the light coming from the objects.

Description

A WATER BASED MIRROR

Technical Field

The present invention relates to a water-based mirror with increased durability, which is used for decorative purposes, especially in architectural applications, furniture, building facades, interior decoration, showcases, medical industry, automotive industry, and for creating the reflection of objects by reflecting the lights coming from the objects.

Prior Art

Mirrors are used for decorative purposes, especially in architectural applications, furniture, building facades, interior decoration, showcases, medical sector, automotive sector in order to reflect the images of objects. Mirrors consist of one or more layers deposited (coated) on a glass sheet. The ability of the mirror to reflect incoming light is provided by the metallic layer deposited on the glass surface. The said metallic layers are usually metals with high reflectivity, such as silver or aluminum.

Corrosion-related deterioration is frequently observed in mirrors used in architectural applications. In the said embodiment, mirrors are used especially in outdoor applications open to atmospheric conditions and in interior applications such as bathrooms exposed to high humidity. Exposure of the mirror to the external environment causes the mirror to be eroded due to external factors. In addition, atmospheric gases and other liquid and solid chemicals in the environments in which they are used cause wear and/or corrosion of the mirrors used in these applications. Abrasion of the mirror causes the mirror to lose its reflective property. This abrasion causes the product to become unusable. In architectural applications, mirrors with reflective properties are used by depositing a metal with high reflectivity on the glass surface. In this application, metal is deposited on one surface of the glass. Protective paint is applied on the metallic layer to protect the metallic layer against external influences. In this protective paint application, paints consisting of an organic-based carrier resin and an inorganic filler material are generally used. Paints can be water-based or solventbased, depending on the solvent material they contain. Protective paints can be applied in different number of layers, such as single, double, triple, depending on their content and ultimate durability properties.

In an embodiment in the state of the art, the paints used in the mirrors consist of two different types of paints. The different types of paints in question are primer and topcoat paints. Each of these two types of paints contains about 30% by weight xylene and similar aromatic solvents. The application of the protective paint is done with the curtain coater. Curtain coater is open to atmospheric environment. In the said application, viscosity adjustment is made so that the paint can be applied without any problems. Viscosity adjustments are made with chemical solvents. Mirror paints having lower solvent content, usually epoxy or alkyd based, applied as a single coat are generally high cost.

In another state-of-the-art embodiment, water-based paint is applied with curtain coater equipment. Water-based paints are applied in different layers depending on the type of resin the paint contains. In the said application, problems are seen in some parts of the paint-bome curtain coating equipment. Intense foam formation is observed in the mixer tank and pump parts where the paint flow is provided, due to the structure of the paints used. The foam formation causes tears in the paint curtain and so inefficient production.

In another state-of-the-art embodiment, water-based paint is applied with curtain coater equipment. Due to being open the curtain coater to the atmospheric environment, foam formation is observed especially in the mixer tank and pump elements where the paint flow is provided. These foams are in some cases too small to be noticed with the naked eye. Small foams cause bubbles and defects on the paint surface of the mirror after application. These defects cause the mirror paint layer to have a porous structure. These bubbles and defects on the paint reduce the durability of the paint. In another case, it reduces the corrosion resistance of the mirrors.

As explained above, it is very possible for mirrors to corrode in atmospheric and other environmental conditions. In the state of the art, a protective paint is applied to prevent the mirror from being abraded. Embodiments in the state of the art are inefficient in terms of cost. In addition, in the state of the art, it is very possible for defects to occur during the application of protective paint, which is carried out with curtain coater equipment.

Thanks to the present invention, a water-based mirror with increased durability is realized by preventing the formation of foam in the mixing tank and pump parts of the curtain coating equipment and by using water-based paint.

Objects of the Invention

The object of the present invention is to realize a water-based mirror in which its metallic layer is preferably protected with a single coat of water-based mirror paint.

Another object of the present invention is to realize a water-based mirror using a water-based paint system in order to protect the metallic layer of the mirror.

Another object of the present invention is to realize a water-based mirror with a paint in which the viscosity adjustment is made using water during production in curtain coating equipment where applications are made that are open to atmospheric conditions. Another object of the present invention is to realize a water-based mirror on which defects are not observed by preventing foam formation in the mixer tank and the pump elements during production and does not require an additional protective layer.

Brief Description of the Invention

This invention is particularly suitable for use in architectural applications in order to obtain images by reflecting lights coming from objects.

A water-based mirror, as defined in the first claim and the other claims, realized in order to achieve the object of the present invention, is a glass sheet, in its most basic form, comprising: a metallic layer overlying the glass sheet; at least one protective layer overlying the metallic layer; at least one adhesion layer in the portion of the protective layer where it contacts the metallic layer; and at least one paint layer overlying the adhesion layer.

The water-based mirror of the invention consists of three basic layers. The said layers are the glass sheet, the metallic layer and the protective layer.

The glass sheet constitutes the basic structure of the inventive water-based mirror. The glass sheet is made of glass material. The glass sheet may be completely transparent, colorless, tinted glass with a coating applied to the glass surface or with the glass composition.

The metallic layer is positioned above the glass sheet. The metallic layer is used to highly reflect the incoming light. Silver layer is preferably used as the metallic layer, the metallic layer is made of silver. While producing the metallic layer, the silver deposition method is used. In a different embodiment of the invention, an aluminum layer is used as a reflective layer, and the metallic layer is obtained from aluminum. While producing the metallic layer, the aluminum deposition method is used under vacuum.

The protective layer is above the metallic layer. The protective layer is used to prevent corrosion of the metallic layer. It consists of protective layer, adhesion layer and paint layer.

The adhesion layer forms the lower part (base) of the protective layer. The adhesion layer is used to combine the protective layer with the metallic layer.

The paint layer is above the adhesion layer. The said paint layer is used to prevent corrosion of the metallic layer by covering the adhesion layer, hence the metallic layer. The paint layer is used to increase the resistance of the metallic layer against abrasion, external exposures and corrosion.

Detailed Description of the Invention

A water-based mirror realized to achieve the object of the present invention is shown in the attached figures, which are:

Figure 1. is a schematic view of the layers of a water-based mirror according to the present invention.

The components given in the figures are enumerated individually, and the meanings of these numbers are given below.

1. Water-based mirror

2. Glass sheet

3. Metallic layer

4. Protective layer

4.1. Adhesion layer 4.2. Paint Layer

The invention is a water-based mirror (1) with increased durability, particularly used in architectural applications, in the automotive sector, in the medical sector, for decoration purposes and to reflect the lights coming from the objects, comprising: a glass sheet (2) forming the base layer, a metallic layer (3) on the glass sheet (2) to reflect the image, a protective layer (4) on the metallic layer (3), used to prevent the metallic layer (3) from being abraded and damaged, characterized in that; the protective layer (4) comprises at least one adhesion layer (4.1) and at least one paint layer (4.2), it comprises a silane -based adhesion layer (4.1), which is located between the metallic layer (3) and the paint layer (4.2), completely covers the metallic layer (3) and enables the metallic layer (3) and the paint layer (4.2) to adhere to each other, it comprises a water-based paint layer (4.2), which is located above the adhesion layer (4.1), comprises water-dispersible acrylic resin and filler, and ensures increasing the durability by protecting the metallic layer (3) against external effects by covering the adhesion layer (4.1) and thus the metallic layer (3).

The water-based mirror (1), which is the subject of the invention, is used particularly in architectural applications, decorations and in the automotive sector to reflect the image.

The water-based mirror (1), which is the subject of the invention, consists of a glass sheet (2), a metallic layer (3) and a protective layer (4).

The glass sheet (2) constitutes the base layer of the water-based mirror which is the subject of the invention. The glass sheet (2) is manufactured from silica and silica based materials. The color and thickness of the glass sheet (2) may vary according to the preferred embodiment of the invention. The glass sheet (2) can be colored with the chemicals added into the glass composition or the coatings applied to the first surface of the glass. On the second surface of the glass sheet (2), there is a metallic layer (3).

In the preferred embodiment of the invention, the second surface of the glass sheet (2) is cleaned and polished. Before the metallic layer (3) is placed on the glass sheet (2), the glass sheet (2) is cleaned and polished. The glass sheet (2) is first cleaned using a cerium oxide chemical with the help of a brush. In the said embodiment, wetting agent can preferably be added to the cerium oxide chemical to increase the efficiency of cleaning. During the cleaning phase of the glass sheet (2), the brushes clean the surface of the glass sheet (2) with horizontal, vertical, diagonal and circular movements. It is ensured that the cleaning process is carried out homogeneously with the brush movements in question. After the cleaning process, the cerium oxide chemicals remaining on the glass sheet (2) are removed from the glass sheet (2) with the help of cleaning water. Deionized water is preferably used as cleaning water in order to prevent contamination, especially deformation and white clouding defects caused by cerium oxide on the glass sheet (2). The resistance of said cleaning water is at least 5 Ma-cm.

In the preferred embodiment of the invention, the sensitization process is performed on the glass sheet (2). The said sensitization process is carried out in order to hold the metallic layer (3) on the glass sheet (2) more firmly. The glass sheet (2) is sensitized by applying stannous chloride solution on the cleaned glass sheet (2). By applying a stannous chloride solution on the cleaned glass sheet (2), tin zones are formed in the glass sheet (2), which serve as nucleation centers for the silver layer deposition process. This serves to speed up the silver deposition rate and to improve the adhesion of the silver to the glass sheet (2). The surface of the sensitized glass sheet (2) is activated using palladium solution. This application increases the valency of the tin that serve as nucleation centers for the silver layer deposition process. This serves to speed up the silver deposition rate and to improve the adhesion of the silver to the glass sheet (2). After said sensitization and surface activation processes, the glass sheet (2) is cleaned with cleaning water. In order for the metallic layer (3) to spread more homogeneously on the surface while it is being formed, the glass sheet (2) is not dried.

The metallic layer (3) is on the upper surface of the glass sheet (2). Said metallic layer (3) is manufactured from metals having high reflectivity. The metallic layer (3) is preferably made of silver. The metallic layer (3) is the layer that reflects the light beams coming from objects.

In the preferred embodiment of the invention, the metallic layer (3) is formed from silver-ammonia compounds and by silvering deposition method. The silvering deposition process is carried out by the chemical wet precipitation method. After the sensitization solution is thoroughly rinsed from the surface of the glass sheet (2) with deionized water and the surface of the glass sheet (2) is still wet, silvering chemicals are sprayed onto the sensitized glass sheet (2). The silver deposition method is carried out by applying silver, abrasive and reducing agents to the surface. The most commonly used chemical precipitation system consists of three separate solutions: a silver solution such as silver nitrate, a caustic such as sodium hydroxide, and a reducing agent such as dextrose. The three chemicals come together by simultaneously spraying the solutions onto the glass surface (2). The chemical reaction that occurs causes a silver layer to precipitate. The chemicals are transferred to the surface of the glass sheet (2) with the help of spray. The speed and frequency of the spray process and the targeted silver layer thickness are adjusted. After silvering is complete, the solutions are thoroughly rinsed from the glass to terminate the precipitation reaction.

In the preferred embodiment of the invention, the passivation of the metallic layer (3) is optimized. To increase the corrosion resistance of the metallic layer (3), the metallic layer (3) is passivated. The passivation process is carried out after the silvering process. The passivation process is carried out by increasing the number of tin atoms on the metallic layer (3). Said passivation is achieved by forming a precipitate layer on the metallic layer (3) with a cation solution containing tin (normally SnC12) and an anion solution consisting of hydroxyl ions (e.g. NaOH). Corrosion is prevented on the reflective silver surface (3) obtained with this waterinsoluble precipitate formed.

In the preferred embodiment of the invention, the production of the metallic layer (3) is carried out using the wet deposition technique.

In a different embodiment of the invention, the production of the metallic layer (3) is formed by using chemical vapor deposition, physical vapor deposition or sputter deposition methods.

The protective layer (4) is on the metallic layer (3). Said protective layer (4) is used to protect the metallic layer (3) against external exposures. The thickness and color of the protective layer (4) can vary. The protective layer (4) consists of the adhesion layer (4.1) and the paint layer (4.2).

The adhesion layer (4.1) is on the surface of the protective layer (4) where it contacts the reflective layer (3). The adhesion layer (4.1) is located between the paint layer (4.2) and the reflective layer (3). The adhesion layer (4.1) is used to ensure that the paint layer (4.2) adheres more firmly to the surface of the reflective layer (3).

In the preferred embodiment of the invention, the adhesion layer (4.1) is formed with the help of silane coupling agents. In the said embodiment, a chemical with an organosilane structure is used. The -OH ends in the structure of the organosilane chemical are attached to the surface of the metallic layer (3). The organic (-R) end of the organosilane chemical is attached to the paint layer (4.2). This situation establishes a bond between the metallic layer (3) and the paint layer (4.2) and ensures that the layers adhere to each other better. In this way, the resistance of the mirror against abrasion and corrosion is increased with the increased adhesion formed between the metallic layer and the paint layer.

The paint layer (4.2) is above the adhesion layer (4.1). The paint layer (4.2) is used to protect the metallic layer (3) against external exposures. The color of the paint layer (4.2) changes. In the preferred application of the invention, the paint layer (4.2) is formed by using water-based acrylic paint, the main solvent of which is water. The main solvent of the water-based paint used is water. Therefore, it has the advantage of containing very low volatile organic (VOC) content. Another advantage of water-based paint is that it has a stable viscosity value, since the main solvent is water. Thanks to this feature, it works efficiently in curtain coater equipment during application. Another advantage of water-based mirror paint is that it is water-based, so it has low odor and is easy to clean with water. This feature allows environment-friendly operation both during application and line cleaning. The fact that the water-based mirror paint is acrylic-based gives flexibility to the protective paint after drying; this flexibility ensures that the water-based mirror can be easily processed in machining conditions such as cutting, grinding, beveling. Inorganic filling materials used in the water paint system used in the invention are homogeneously dispersed in the water-based paint system. The film layer formed by the filling materials used is resistant to water and humidity.

In the preferred embodiment of the invention, the paint layer (4.2) is carried out by the curtain coating method. Curtain coating equipment is open to the atmospheric environment. There is paint in the reservoir of the curtain coating equipment. The paint is poured onto the glass plate moving on the conveyor with the help of the roller moving in the chamber. With the continuity of the curtain, a homogeneous and one-piece coating is formed. The curtain forming performance of the paint depends on the paint structure and application viscosity. The application viscosity value of the water-based paint used in the invention is preferably 40-60 sec CF4@20 °C. The thickness of the coating is controlled by the amount of paint and the feed rate of the mirror. The preferred application amount of the water-based paint used in the invention as wet paint is 140-190 g (140-190 g/m²) for one coat, and 70-95 g (70-95 g/m²) for each coat in double coat application per 1 m² of glass.

In the preferred embodiment of the invention, the paint layer (4.2) can be applied as a single or double layer. Especially in the application of a single layer of paint (4.2), water-based paint is applied to the glass surface, preferably with a dry film thickness of 40-60 pm, preferably at 140-190 g wet paint (140-190 g/m²) on 1 m² glass. To the applied paint layer (4.2), a pre-drying at 50-90 °C for 2 minutes; and then a second drying process during which the actual drying is carried out for 5-10 minutes at 140-190 °C are applied. In the pre-drying process, the amount of water contained in the water-based paint is reduced by evaporation. In the second drying process, the single coat paint layer (4.2), in which the water in its content is removed with the first drying, performs its final curing with the applied heat. In the case of double-coat paint application, the first coat of paint is applied, preferably with a dry film thickness of 20-30 pm, preferably at 70-95 g wet paint (70-95 g/m²) on 1 m² glass. In the pre-drying oven, the water in the structure of the paint is evaporated and removed. Afterwards, a second coat of paint is applied, preferably with a dry film thickness of 20-30 pm, preferably at 70-95 g wet paint (70-95 g/m²) on 1 m² glass. In the second drying process, the water in the second layer of paint is evaporated away, while the heat curing process is also carried out.

In the preferred embodiment of the invention, pre-drying and then curing processes are applied to the paint layer (4.2). The curing type and conditions vary according to the physical and chemical properties of the paint layer (4.2). In the preferred embodiment of the invention, the paint layer (4.2) is formed using an acrylic -based, one-component and water-based paint. In the said application, the chemical curing of the paint layer (4.2) takes place with the help of heat.

In the preferred embodiment of the invention, a water-based paint system consisting of an acrylic -based carrier resin system, inorganic pigment and other filling materials is used to form the paint layer (4.2). The physical and chemical properties of all components of the paint system in question are designed to increase the curtain forming performance during the application of the paint. The particle size distribution of the organic and inorganic components of the water-based paint system provides effective coverage and creates a homogeneous coating. These features enable the inventive water-based mirror (1) to be easily processed. Acrylicbased carrier resin, which is the component of the water-based paint system, is a resin with high chemical resistance; its main solvent is water, and it contains very, very low percentages of volatile organic solvents. In addition, inorganic fillers, which are among the other components of the paint system, contain anti-corrosion pigments that protect the metallic layer against corrosion.

In the preferred embodiment of the invention, the water-based paint system used to form the paint layer (4.2) consists of solid and liquid components. Solid components constitute 50-70% by weight of the paint system. Organic compounds constitute 30-50% by weight of solid components and inorganic compounds constitute 50-70% by weight of solid components. The organic solid materials used in the paint system are water-dispersible aery lie -based resins. Inorganic solid materials are fillers and pigments. The liquid component constitutes 30-50% of the paint system by weight. At least 95% by weight of the liquid content is water, which is the main solvent, and a maximum of 5% is organic solvent.

Claims

CLAIMS The invention is a water-based mirror (1) with increased durability, particularly used in architectural applications, automotive industry, medical industry, for decoration purposes and to form the image of objects by reflecting the light reflected from the objects, comprising: a glass sheet (2) forming the base layer, a metallic layer (3) on the glass layer (2) in order to reflect the light coming from the objects, a protective layer (4) on the metallic layer (3), used to prevent the metallic layer (3) from being abraded and damaged, characterized in that; the protective layer (4) of the body comprises at least one adhesion layer (4.1) and at least one paint layer (4.2), it comprises a silane-based adhesion layer (4.1), which is located between the metallic layer (3) and the paint layer (4.2), completely covers the metallic layer (3) and enables the metallic layer (3) and the paint layer (4.2) to adhere to each other, it comprises a water-based paint layer (4.2), which is located above the adhesion layer (4.1), comprises water-dispersible acrylic resin and filler, and ensures increasing the strength by protecting the metallic layer (3) against external effects by covering the adhesion layer (4.1) and thus the metallic layer (3). The water-based mirror (1) according to Claim 1, characterized in that; before the metallic layer (3) is placed on the glass sheet (2), cleaning and polishing operations are performed on the glass sheet (2) by using cerium oxide chemical. The water-based mirror (1) according to Claim 2, characterized in that; the cerium oxide residues found on the glass sheet (2) on the glass sheet (2) are cleaned with deionized water with a resistance of at least 5 Ma-cm to prevent the formation of cerium oxide-induced deformation and white clouding. The water-based mirror (1) according to Claim 1, characterized in that; by applying tin chloride solution on the glass sheet (2), the glass sheet (2) is sensitized and the adhesion of the metallic layer (3) is increased on the glass sheet (2). The water-based mirror (1) according to Claim 1, characterized in that; the surface of the glass sheet (2) is activated by applying a palladium chloride solution on the glass sheet (2), before the metallic layer (3) is placed on the glass sheet (2). The water-based mirror (1) according to Claim 1, characterized in that; it comprises the silver metallic layer (3) obtained by using chemical wet precipitation method. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the metallic layer (3) with increased resistance to corrosion, which is passivated by increasing the number of tin atoms on its surface by applying an acid-containing aqueous solution of tin salt thereon. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the silver metallic layer (3) obtained by using one of the chemical wet precipitation, chemical vapor deposition, physical vapor deposition or sputter deposition methods. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the aluminum metallic layer (3) obtained by using one of the chemical vapor deposition, physical vapor deposition or sputter deposition methods. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the passivated metallic layer (3) obtained by forming a precipitate layer by applying thereon a cation solution containing tin and an anion solution consisting of hydroxyl ions. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the paint layer (4.2) with a viscosity value of 40-60 sec CF4@20 °C. The water-based mirror (1) according to Claim 1, characterized in that; it comprises the paint layer (4.2) formed of wet paint in the amount of 140-190 g (140-190 g/m²) for one coat, and in the amount of 70-95 g (70-95 g/m²) for each coat in double coat application per 1 m² of glass. The water-based mirror (1) according to Claim 1, characterized in that; it comprises paint layer (4.2) such that the water-based paint would be preferably 140-190 g wet paint (140-190 g/m²) per 1 m² glass sheet (2), therefore, having a dry film thickness of 40-60 pm on the glass sheet (2), especially in single coat paint application. The water-based mirror (1) according to Claim 1, characterized in that; in case of double coat paint application, it comprises at least one paint layer (4.2) formed such that a first coat of paint would be applied on the glass sheet (2) with a dry film thickness of 20-30 pm, preferably 70-95 g wet paint (70-95 g/m²) per 1 m² glass, and then another coat of paint would be applied with the dry film thickness of preferably 20-30 pm, and 70-95 g wet paint (70-95 g/m²) per 1 m² glass. The water-based mirror (1) according to Claim 1, characterized in that; it comprises at least one paint layer (4.2) obtained by using a paint consisting of 50-70% by weight of solid components; wherein 30-50% by weight of solid components are composed of organic components (water-dispersible acrylicbased resin), and 50-70% by weight of inorganic compounds (fillers and pigments); and consisting of 30-50% by weight of liquid components, wherein the liquid content consists of at least 95% by weight of water, which is the main solvent, and at most 5% of organic solvents.

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