BEFORE HEAT TREATMENT

DESCRIPTION

The present invention relates to the inorganic paint which enables paint application on the materials such as glass, metal, ceramic etc. before the surface treatment, conveyance and transfer procedures and which is applied on the mentioned painted surfaces before the heat treatment (tempering, annealing), without being damaged during cutting, lapping, boring, deburring, conveyance and transport processes.

Various heat treatment processes (tempering, annealing etc.) are applied on the materials such as glass, metal, ceramic etc. in order to bring toughness (strength) in them and make the carbon atoms within their structures stable (steady). Tempering, which is a heat treatment process applied especially on glass, enables glass to be stronger and securer. Tempered glass which had undergone heat treatment is used at places such as motor vehicles, building facades, balconies, winter gardens, office partitions, elevators, display windows, shower cabins, industrial coolers, stairs. Tempered glass (heat treatment application) is resistant against impacts and heat 4-5 folds more when compared to the normal glass. Moreover, when tempered glass is broken, it breaks into very small pieces in the size of a dice, which is less sharp. Due to this reason, tempered glass is securer when compared to normal glass.

Glass tempering process is based on the process of controlled heating of the glass almost up to the melting point (625 - 645 °C) in special furnaces and rapid cooling afterwards. With tempering process, the glass surface is provided with about 6000 Pa (Pascal) of compression stress and an indirect tensile stress on the center of the glass. Due to such stresses, the processes such as cutting, dimensioning, lapping, boring, deburring, grinding, counter boring, chamfering cannot be applied. Tempered glass breaks if these mentioned processes are applied. Consequently, the processes such as cutting, dimensioning, lapping, boring, deburring, grinding, counter boring, chamfering are applied on the glass prior to the tempering process. No other process can be applied on the glass following the tempering process, except sanding and painting. Glass can be colored by various methods as based on areas of use. In industrial productions, glass coloring is usually realized by application of paint on glass surface. Such paints applied on glass surface are in two groups as organic paints (varnish, mirror effect paints and covering paints) and inorganic paints (temper paints, crystal glass paints, silver resistance paints). Among those paints mentioned, the most common one with the broadest area of use in the glass industry is temper paint. Temper paint (also known as enamel paint) is applied on the glass surface by screen-printing, roller printing, spray printing etc. methods.

Heat treatment is applied following the glass coloring and painting carried out specifically by temper paint so that paint adheres to the glass completely and becomes smooth (even, stable) on the application surface. Tempering and tensional heat treatment processes are applied on the glass painted by printing or spraying methods. This way, the paint integrates with the glass. Due to this reason, it is more appropriate to paint the glass before the tempering process in the production of painted glass, in the state of the art, there are also applications in which the paint is applied on the tempered glass and the glass is again subjected to heat treatment. However, such applications result in problems with respect to labor, cost and the structure of the glass.

In the state of the art, the glass in which surface treatment is completed and painted afterwards is directly transferred to the tempering furnaces. The existing temper paints do not have the adherence capability to the glass surface before the tempering process. Before the tempering process, the paint on the surface of the glass can easily fall off from the surface. Due to this reason, the painted glass cannot be subjected to any surface treatment and cannot even be transferred within the facilities. As a result, only the glass with completed surface treatments and placed on the tempering line can be painted. When it is taken into account that also the tempered glass cannot be subjected to any surface treatment, just like painted glass, it is required that each glass treatment facility has a printing and coloring section within its own structure. In the present state, only the large scale producers can apply glass coloring together with glass processing. In the state of the art, colored tempered glass production under or over a certain quantity cannot be carried out.

The disadvantages in the state of the art arise due to inability to transfer the painted glass before the tempering treatment even within the facilities and inability to apply any surface treatment to on the painted glass (before or after tempering). This state is due to the fact that available temper paints do not have the ability to adhere to the glass surface before the tempering process.

In the structure of the inorganic temper paints available in the state of the art, generally solvents, ceramic oxides, metal oxides, frit and some silicates. Solvents dissolve the chemical substances into its components. The solvents in the content of the current paints provide the paint to spread homogenously on the application surface

Silicates, specifically siiisium dioxide (Si0 ₂ ) and ethyl silicates are used as binders in inorganic glass paints.

Frit (ceramic and/or metal oxide mixture) provides curing of the paint at a certain temperature. Frit is the ceramic and/or metal oxide mixture prepared at certain prescriptions. Frit (intermediary product with glass structure) mixtures determine the life and quality of the paint.

In the state of the art, there are inorganic glass paints containing some protective and viscosity adjuster chemicals in addition to above. The current inorganic glass paints don't have the capability to adhere to the glass surface before the heat treatment. This state causes the occurrence of the problems mentioned above.

The present invention relating to the inorganic paint which enables paint application on the materials such as glass, metal, ceramic etc. before the surface treatment, conveyance and transfer procedures and which is applied on the mentioned painted surfaces before the heat treatment (tempering, annealing), without being damaged during cutting, lapping, boring, deburring, conveyance and transport processes, completely overcomes the disadvantages mentioned above and it is characterized by containing;

Solvent mixture at the rate of 15 - 25%

- Ethyl cellulose at the rate of 1 - 2%

- Frit at the rate of 50 - 70%

Dispersion agent at the rate of 1 - 5%

- Viscosity adjuster at the rate of 1 - 5%

AND thermosetting resin providing adherence at the rate of 2 - 5 %

ideally in the structure of the paint. The reason for using solvents as mixtures in the mentioned inorganic paint is the prevention of sudden solvent output in the drying furnaces and as a result, avoidance of the burns which may occur on the surface of the paint. Due to this, solvents with different evaporation temperatures are used as mixtures. Ethyl cellulose adjusts the consistency of the present inorganic paint and brings its rheology (flow of the condensed materials) to the desired point.

Frit is characterized as the inorganic resin mixture (mix metal oxide mixture) in the present inorganic paint which provides the curing of the paint at a certain temperature and adherence to the surface. Dispersion agent prevents coagulation of the solid particles in time, which are homogenously spread (dispersed) in the present inorganic paint. Moreover, it provides the homogenous dispersion of the resin and fillings in the paint, which are in a solid state.

Viscosity adjusters are the liquid chemicals that provide the adjustment of the viscosity of the present inorganic paint. The present inorganic paint is characterized by containing thermosetting resin which provides adherence on the glass, metal, ceramic etc. surfaces before the heat treatment. Thermosetting resin providing adherence reacts with the inorganic resin (frit) within the structure of the inorganic paint and provides the adherence of the paint on the glass, metal, ceramic etc. surfaces before the heat treatment. Thermosetting resin providing adherence burns at high temperatures and does not leave ash or marks on the application surface. Moreover, the mentioned thermosetting resin is cured between 120 - 170 °C.

When thermosetting resin reacts with inorganic resin, polymerization reaction starts. During polymerization reaction, frequent covalent cross links are established between the molecules within the structure of resin. The molecular network created by these cross links makes the resin, which is a melting and soluble substance in the beginning, a polymer which does not melt or dissolve by the end of the polymerization. This molecular network (polymer) formed within the structure of the paint provides the paint to have dimensional stability. The impact resistance of the inorganic paint with the dimensional stability also increases. In conclusion, the resistance and stable structure which is desired to be obtained by heat treatment is provided by the polymerization reaction between the resins. When inorganic paint with dimensional stability and impact resistance is applied on surfaces such as glass, metal, ceramic etc., adheres to the surface also before the heat treatment. This way, the glass painted before tempering process can be transferred and all types of surface treatments can be applied. The glass, metal, ceramic etc. surfaces painted prior to the heat treatment, with temper paint, which shows a high strength can be transported to the desired distances. Inorganic paint applied on a glass, metal, ceramic etc. surface is not damaged during the transfer, conveyance and transport processes. All types of surface treatments (cutting, dimensioning, lapping, boring, deburring, grinding, counter boring, chamfering) can be applied on the surfaces painted with inorganic paint containing resin providing adherence. Tempering paint with high strength prior to the heat treatment is not damaged during the mentioned surface treatments.

Thanks to inorganic paint which is not damaged during transfer, transport and surface treatments, colored temper glass production at any dimension, subjected to the desired surface treatment, is enabled. By means of the present invention, painted glass in large dimensions can be transferred and dimensioning and surface treatment applications can be earned out. Afterwards, these can be transferred again and be subjected to tempering treatment. This state allows the glass treatment facilities to be specialized separately on surface treatment, coloring and heat treatment processes and as a result, offering better quality products to the market.