Method for serigraphic printing on a glass plate and glass plate obtained thereby

Abstract

 Method and glass plate obtained by it, wherein a base layer and a layer with decorative patterns above it are placed in contact with the surface of the glass plate, such that the method is simple and reliable and the plate presents well-defined and lasting decorative patterns.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention belongs to the field of glass plate surface treatments, and specifically those using two superimposed coatings, as well as the glass plates obtained by this treatment.

[0002] This invention consists of a method and the glass plate obtained by it, wherein a base layer and a layer with decorative patterns above it are placed in contact with the surface of the glass plate such that the method is simple and reliable and the plate presents well-defined and lasting decorative patterns.

BACKGROUND OF THE INVENTION

[0003] Methods for serigraphic printing on glass plates and the plates thereby obtained with decorative patterns formed by two superimposed layers of paint are both known.

[0004] The same applicant discloses in patent PCT/ES2005/070178 a method and product obtained by it, in which a paint layer with decorative patterns is deposited, and above it is placed a base layer that is subsequently eliminated in the areas where it does not coincide with the decorative patterns.

[0005] However, the known methods and products present a number of drawbacks and disadvantages, such as the decorative patterns presenting halos around their peripheral edge, or shadows in some of their areas due to the separation of the decorative patterns from the surface of the glass.

[0006] In addition, the paints are solvent-based and stain the machinery, for example during the final washing, so that the washing installation is special and a standard washing area cannot be used.

[0007] Moreover, in known processes the paints are vitrified before washing, so that, together with the solvent-based nature of the paint, fumes are released in the oven that stain it, underscoring the need for the subsequent special washing installation.

[0008] As this washing acts on vitrified paint, it must be strong enough to remove it where desired, implying the possibility of also removing the decorative patterns desired, which are eliminated in a random and uncontrolled manner.

[0009] To overcome the above-described drawbacks of the state of the art, a description is provided of the method and the glass plate obtained by it, wherein a base layer and a layer with decorative patterns above it are placed in contact with the surface of the glass plate, such that the method is simple and reliable and the plate presents well-defined and lasting decorative patterns.

DESCRIPTION OF THE INVENTION

[0010] The present invention is established and characterised in the independent claims, while the dependent claims describe additional characteristics thereof.

[0011] In view of the above, the present invention relates to a method for serigraphic printing on a glass plate of decorative patterns comprising two layers of paint of different colours, one of which is the base layer and the other is the decorative pattern layer, with the following stages:

• serigraphic printing on a surface of the glass plate of the base layer, which is continuous and larger in area than the decorative pattern layer;
• drying the base layer;
• serigraphic printing on the base layer of the decorative pattern layer, which is discontinuous and smaller in area than the base layer;
• drying the decorative pattern layer;
• washing to remove the portion of the base layer that differs from the decorative patterns;
• firing to vitrify both paint layers.

[0012] One advantage of this method is its simplicity, as the stages use the usual stations and devices, such as drying, washing and firing, which require no special equipment.

[0013] Another resulting advantage is its reliability, as it does not introduce any uncontrolled variables due to stages unknown in the field, or expensive and complex specialised machinery.

[0014] In addition, the present invention relates to a glass plate with decorative patterns according to the above-described method, which comprises decorative patterns made with two superimposed layers of water-based paint, the layer in contact with the surface of the glass plate corresponding to the base layer and that above it corresponding to the decorative pattern layer.

[0015] One advantage of this glass plate is that the decorative patterns are well defined, as the arrangement of the layers allows them to adhere correctly to the glass plate, avoiding any optical aberrations.

[0016] A further advantage of this glass plate is the durability of the decorative patterns, as they have been vitrified, the outermost layer with the decorative patterns protecting the inner base layer, thereby providing an extraordinary resistance to external agents, and even protecting against accidental scratches or detachment due to scrapes or collision with objects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] This specification is supplemented with a set of drawings illustrating the preferred embodiment, which are never intended to limit the invention.

Figure 1 shows a cross-sectional view of the glass plate with the base layer.

Figure 2 shows a cross-sectional view of the glass plate with the base layer and the decorative pattern layer.

Figure 3 shows a cross-sectional view of the glass plate with the base layer and the decorative pattern layer, in which the portion of the base layer that is different from the decorative pattern layer has been removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0018] The present invention is a method for serigraphic printing of decorative patterns on a glass plate (1), and the glass plate thereby obtained.

[0019] In the method the decorative patterns on the glass plate (1) are formed by two layers of paint of different colours (2,3). In this way, when looking at the plate (1) from one side, normally that facing the inside of the room and to which the decorative patterns are attached, from a certain distance nothing can be seen on the plate (1), that is, it appears to be completely transparent. However, from the other side of the plate (1), normally that facing the outside, the decorative patterns can be clearly seen, fulfilling their intended function, such as displaying advertising or the corporate image of a company in the glass on the building façade.

[0020] The paint layers, the base layer (2) and decorative pattern layer (3) are attached by serigraphic printing, using the screens commonly employed, to the glass plate (1) in the following stages:

• serigraphic printing on a surface of the glass plate (1) of the base layer (2), which is continuous and larger in area than the decorative pattern layer (3);
• drying the base layer (2);
• serigraphic printing on the base layer (2) of the plate with the base layer.

Figure 2 shows a cross-sectional view of the glass plate with the base layer and the decorative pattern layer.

Figure 3 shows a cross-sectional view of the glass plate with the base layer and the decorative pattern layer, in which the portion of the base layer that is different from the decorative pattern layer has been removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0021] The present invention is a method for serigraphic printing of decorative patterns on a glass plate (1), and the glass plate thereby obtained.

[0022] In the method the decorative patterns on the glass plate (1) are formed by two layers of paint of different colours (2,3). In this way, when looking at the plate (1) from one side, normally that facing the inside of the room and to which the decorative patterns are attached, from a certain distance nothing can be seen on the plate (1), that is, it appears to be completely transparent. However, from the other side of the plate (1), normally that facing the outside, the decorative patterns can be clearly seen, fulfilling their intended function, such as displaying advertising or the corporate image of a company in the glass on the building façade.

[0023] The paint layers, the base layer (2) and decorative pattern layer (3) are attached by serigraphic printing, using the screens commonly employed, to the glass plate (1) in the following stages:

• serigraphic printing on a surface of the glass plate (1) of the base layer (2), which is continuous and larger in area than the decorative pattern layer (3);
• drying the base layer (2);
• serigraphic printing on the base layer (2) of the decorative pattern layer (3), which is discontinuous and smaller in area than the base layer (2);

• drying the decorative pattern layer (3);
• washing to remove the portion of the base layer (2) that is different from the decorative pattern layer (3);
• firing to vitrify both paint layers (2,3).

[0024] The base layer (2) creates a continuous substrate, without interruptions, on which is deposited the decorative pattern layer (3). This allows ensuring that the shape left of the base layer (2) is at least that of the decorative patterns (3) and never smaller, as the starting point is a continuous surface, which is much larger than that of the decorative patterns.

[0025] In this preferred embodiment drying is performed by irradiation with infrared lamps, but any other known method is possible. In addition, washing is performed by spraying in a shower and firing is performed in a conventional oven.

[0026] An advantageous option is the paint of both layers (2,3) is water based, as this allows a simple elimination during washing with usual equipment and provides a greater assurance that the decorative pattern layer (3) will not be removed, as occurs when using solvent-based paints for which strong washing is used.

[0027] Another feature of the method is that the firing of each layer (2,3) takes place from 600 to 700°C, for a period of 35 to 55 seconds for each millimetre thickness of the glass, these values resulting in a correct vitrification of the paint.

[0028] The decorative patterns have a variable shape and size to provide different appearance, The base layer (2) has a light colour and the decorative patterns layer (3) has a dark colour to achieve a chiaroscuro effect.

[0029] In addition, in tests performed with several paints, a certain viscosity of the paint for a serigraphic screen provides the best results. Thus, a viscosity greater than 30,000 cps is selected using a Brookfield Viscometer with disc 7 at a speed of 20 rpm or in a Ford Cup Viscometer, from 80 to 120 seconds at ambient temperature with a 6 mm orifice.

[0030] For this viscosity polyester screens are used with 30T to 95T wires/cm.

[0031] The thickness of each paint layer (2,3) obtained in this way is from 15 to 55 µm.

[0032] With the described method a glass plate (1) is obtained with decorative patterns composed of two superimposed water-based paints, the one in contact with the surface of the glass plate being that corresponding to the base layer (2), and above it the one corresponding to the decorative pattern layer (3).

[0033] In this way, the base layer (2), which is the one normally seen from the room or through the glass plate (1), is always protected from the external agents that affect the outermost layer, the decorative pattern layer (3).

[0034] The decorative patterns have a variable shape and size to provide different appearances.

[0035] Thus, the best results are obtained with a thickness of the paint layer (2,3) from 15 to 55 µm.

Claims

1. Method for serigraphic printing on a glass plate of decorative patterns that comprise two layers of paint of different colours, one being a base layer and another being a decorative pattern layer, characterised in that it comprises the following stages:

- serigraphic printing on a surface of the glass plate (1) of the base layer (2), which is continuous and larger in area than the decorative pattern layer (3);

- drying the base layer (2);

- serigraphic printing on the base layer (2) of the decorative pattern layer (3), which is discontinuous and smaller in area than the base layer (2);

- drying the decorative pattern layer (3);

- washing to remove the portion of the base layer (2) that is different from the decorative pattern layer (3);

- firing to vitrify both paint layers (2,3).

2. Method for serigraphic printing on a glass plate according to claim 1, characterised in that each layer (2,3) is fired at 600 to 700°C, for a period of 35 to 55 seconds for each millimetre of glass thickness.

3. Method for serigraphic printing on a glass plate according to claim 1, characterised in that the paint of both layers (2,3) is water based.

4. Method for serigraphic printing on a glass plate according to claim 1, characterised in that the paint of the base layer (2) has a light colour and that of the decorative patterns layer (3) has a dark colour to obtain a chiaroscuro effect.

5. Method for serigraphic printing on a glass plate according to claim 1, characterised in that the pain has a viscosity greater than 30,000 cps in a Brookfield viscometer with a disk 7 at 20 rpm, or from 80 to 120 seconds at ambient temperature in a Ford Cup Viscometer with a 6 mm orifice.

6. Method for serigraphic printing on a glass plate according to claim 5, characterised in that the serigraphic printing uses a polyester screen with from 30T to 95T wires/cm.

7. Method for serigraphic printing on a glass plate according to claim 1, characterised in that the thickness of each paint layer (2,3) is from 15 to 55 µm.

8. Glass plate with decorative patterns according to the method of the previous claims, characterised in that it comprises decorative patterns composed of two superimposed water-based paints, the one in contact with the surface of the glass plate (1) being that corresponding to the base layer (2), and above it being that corresponding to the decorative pattern layer (3).

9. Glass plate with decorative patterns according to claim 8, characterised in that the base layer (2) has a light colour and the decorative patterns layer (3) has a dark colour, to achieve a chiaroscuro effect.

10. Glass plate with decorative patterns according to claim 8, characterised in that the thickness of each paint layer (2,3) is from 15 to 55 µm.

Drawing