WO2007031151A1

WO2007031151A1 - Method for production of coloured structures in glass and glass produced thereby

Info

Publication number: WO2007031151A1
Application number: PCT/EP2006/007360
Authority: WO
Inventors: Thomas Rainer; Reinhard Borek
Original assignee: Boraglas Gmbh
Priority date: 2005-09-12
Filing date: 2006-07-26
Publication date: 2007-03-22
Also published as: EP1954643A1; DE102005043516A1

Abstract

The invention relates to a method for production of coloured structures in glass, wherein the ions of at least one metal present in glass or introduced during the method are reduced by locally defined energy input, in particular, as the focus of a laser beam and transformed into a locally defined collection of metal particles which give a local colouring typical of the metal used. In order to produce multi-coloured structures, several locally defined regions with a monochrome starting colour which are distinguished by graduations of the same colour are generated in a first step and in a second step particle formation and/or growth processes are induced by a global or local energy input in the regions of the starting colours, such that regions with differing starting colours obtain a different colour. The invention further relates to a glass element comprising an image representation with regions of different colours, produced by the above method.

Description

Process for producing colored structures in glass and glass produced thereby

The invention relates to a method for producing colored structures in the glass, in which present in the glass or introduced by the process ions of at least one metal by localized energy input, in particular in the focus of a laser radiation, reduced and converted into a localized accumulation of metal particles, the a local, typical of the metal used discoloration causes.

In the prior art, in particular from DE 198 41 547, such a method is known. Essential to this known method is that, in a glass after doping, ions of at least one metal, e.g. As a result of a locally limited introduction of energy in the region of this local boundary, a chemical reduction of the silver ions to metallic silver, in particular nanoparticle size, takes place and, depending on the parameters of the energy input, in particular the laser radiation, the accumulation of metal particles in size is changeable.

Thus, it is known, for example, that by means of laser radiation it is possible to be able to write a picture in a doped glass by successively changing the focus position of a laser beam in the glass, which consists of a multiplicity of discolored areas, this discoloration being typical for that metal with which the glass is doped. For example, silver in metal causes a characteristic brown discoloration of the glass.

A disadvantage of this method is that, based on a particular metal used only a variety of areas can be generated, which is the same Have discoloration, so that only "monochrome" images can be written by means of the known method in glass.

The object of the invention is to provide a method by means of which in a simple manner also different colored structures, even when using a doping with only one metal in a glass can be generated.

This is achieved according to the invention in that for the production of multicolored structures in a first step several localized areas are created with an initial coloration, which differ by gradations of the same color and in a second step by a global or local energy input in the areas of the Initial staining dependent particle formation and / or growth processes are induced so that areas of different initial staining get a different color.

It is essential to the essence of the invention that first of all a monochromatic image, as known in principle in the prior art, is obtained by repeatedly changing the position of a partially limited energy input, e.g. is registered in the focus of a laser beam into the glass, whereby monochrome areas are generated, the color of which is typical for the doping metal used in each case.

Here, e.g. by varying the parameters at the localized energy input, the intensity of the discoloration can be varied. For example, particularly when using a laser beam, the irradiation time (pulse duration or length of CW irradiation), irradiation intensity, focus diameter, etc., may be changed to produce different gradations of the same color in different regions of a glass. Accordingly, different optically dense regions of a coloring are produced.

By a subsequent further global (with respect to the whole glass) or even limited local energy input, which acts in particular in the same way on several areas with different initial color, is caused in the areas that have a starting color, one of the initial color dependent further process is induced, in which, for example, further particles form and / or particles grow in size.

In this case, the type and / or strength of the induced process is dependent on the initial coloration that was produced in the first method step according to the invention. The further processes taking place in the second step then ensure that the areas which have an initial coloration and which have undergone this second treatment have a different color at the end of the process.

In this way, starting from a monochrome, color-graded image, ie only different density levels of the same color, images with different colors can be produced.

According to the invention, various methods may be used for localized energy input of the first step, such as electron beam processes, ion implantation or laser processes. In this case, it may be provided in principle that during or before the first step according to the invention, in particular, a local doping of the glass with metal particles takes place.

For this purpose, it can be provided in particular that on a e.g. undoped, or even with another metal-doped glass, a metal ion donor medium is arranged so that by the energy input of the first method step according to the invention in a first period initially a localized doping of the glass with the metal ions of the donor medium takes place, whereupon in a subsequent period of time Step the discoloration of the ions doped in the glass, if necessary, also the existing ions takes place. For example, this can be done by means of focused laser radiation.

In this first step according to the invention, for example, doping takes place by diffusion with metal ions, such as silver ions, from a donor medium when the glass is heated in the focal region, in particular below the glass transition temperature. If the glass reaches a higher temperature, in particular above the transformation temperature, then a reduction of the Glass, for example, by the glass-own or externally supplied reducing agent to a conversion of the ions into metal particles, which leads to the said discoloration with the typical color of the metal used.

In a preferred simple embodiment variant of the method, it may be provided to carry out the first step by means of focused laser radiation, since laser radiation is simple and precise to handle and it is basically known to perform by appropriate devices temporally successive irradiation of a glass in a plurality of limited areas and to create a discoloration to the respective newly shifted focus area, thereby composing an image.

The second step of global or local energy input according to the invention can preferably be carried out by means of a heat treatment, e.g. in a heat treatment device provided for this, with which in particular a homogeneous temperature distribution over the entire glass can be achieved.

Thus, according to the process of the invention in the second step, substantially all areas which have been provided with a monochromatic initial coloration, subjected to the same temperature treatment, this same temperature treatment, however, depending on the initial color, different effects on the respective considered areas.

Thus, it is observed that starting from the intensity of the discoloration and thus essentially the optical density with the same basic coloration which is typical for a certain metal, different final colors are achieved. This can be explained by the fact that further processes are induced by the temperature treatment, for example, which are essentially to be seen in that existing metal particle accumulations increase due to the fact that further particles are added and these particles have substantially the same diameter and / or that existing metal particles have their Change diameter, ie grow and / or the particle concentration changes. The type and the strength of the respective process, whereby also mixed forms of the aforementioned processes are possible, depends on which starting situation in the respective process Range prevails at the subsequent temperature treatment, ie essentially what gradation of monochrome discoloration or which original optical density has been present in the area.

Thus, the process given by the second step of the heat treatment is dependent, for example, on the distribution, concentration and size of the metal ions, metal atoms and metal particles introduced in the glass or in the colored area in the first step and furthermore also on the size and the duration of time the energy input in the first step. In this way, different size distributions, concentrations and local arrangements of the nanometallic particles in the glass are selectively produced locally in the glass by the second step according to the invention, leading to a different color effect.

The found starting situation for the second method step in turn is influenced by the execution of the first method step, i. the reduction and aggregation of metal particles caused by the local energy input.

By using not only one metal or its salts, different metal ions can simultaneously be present in the glass and thus different gradations of several, each based on a metal substantially monochrome colors are produced in a first process step, in which case the subsequent heat treatment to a variety of colors produced can lead.

Explanation is the different color effect after the further heat treatment in that depending on the initial situation, the center of the absorption bands, as they are typical for a certain metal shifts, bands are broader / narrower or more bands arise.

An embodiment is shown in the following figures. Show it:

Figure 1 is a schematic representation of a color to be designed in Figure

Glass 1 shows a schematic representation of an image in a glass body, which was introduced by means of focused laser radiation into the glass, characterized in that this image is traversed at a given resolution successively by shifting the laser focus in the glass point by point. In essence, the figure consists of two circular objects.

First, gradations of a typical silver discoloration (sepia or brown) of about 88% with respect to an optical reference density of this discoloration were produced, such as in the region 1 and 58% in a region 2. The two different optical densities are described here various densities of the pattern used. The pattern in the circles itself is not a detail of the picture but should represent a uniform monochrome color.

The thus generated, substantially monochrome representation of the image, i. the different gradations of the brownish, typical for silver discoloration was then subjected to a heat treatment.

This is done during this permanent and uniform over the entire glass material temperature treatment, a change in the colors, which is explained by the fact that starting from the different gradations different processes of particle formation and particle growth use, so that an initial gray scale of 88% based on a Reference density eg leads to a pale yellow discoloration after the temperature treatment and a 58% gradation leads to a green discoloration. Thus, the image after this temperature treatment now appears in two different colors instead of two gradations of the same color.

This shift of the absorption maxima or the addition of further absorption maxima at additional wavelengths due to the temperature treatment produces color shifts or blending effects that result in the colors in the present examples of light yellow and green starting from the original color sepia typical of silver , Different colors can be generated when other metals are used in the doping, eg gold, copper etc.

It could be shown that by means of a uniform, homogeneous heat treatment of a glass, which only color gradations of a color, i. has different optical densities of a typical absorption band, this original absorption band can be implemented in shifted with respect to their center absorption bands or added additional absorption bands. These changes in absorption produce a phenomenon of different colors of the original monochrome stained structures.

Thus, by means of the invention, multicolored images in glass, e.g. be lasered.

Claims

claims

1. A process for producing colored structures in glass in which present in the glass or introduced by the method ions of at least one metal by localized energy input, in particular in the focus of laser radiation, reduced and converted into a localized accumulation of metal particles, which is a local for the metal used causes typical discoloration, characterized in that for the production of multicolored structures in a first step several locally limited areas are created with a monochrome initial coloration, which differ by gradations of the same color and in a second step by a global or local energy input in the areas induced by the initial dye-dependent particle formation and / or growth processes, so that areas with different initial color receive a different color.

2. The method according to claim 1, characterized in that prior to the generation of localized areas with an initial coloration by localized energy input, in particular in the focus of laser radiation, ions of at least one metal by an arranged on a glass surface ion donor medium in a region to be dyed of the glass.

3. The method according to any one of the preceding claims, characterized in that the first step is performed by means of focused laser radiation.

4. The method according to any one of the preceding claims, characterized in that the second step by means of a Heat treatment apparatus is carried out, in particular in order to achieve a global homogeneous heat input.

5. The method according to any one of the preceding claims, characterized in that by the energy input, in particular the temperature treatment in the second step, a growth of a plurality of metal particles is generated with substantially the same diameter and / or existing metal particles continue to grow and / or new metal particles are generated.

6. The method according to any one of the preceding claims, characterized in that takes place by the energy input in the second step, a change in the absorption bands, in particular by shifting and / or addition of absorption maxima.

7. glass element comprising a pictorial representation with areas of different colors, prepared according to the method of any one of the preceding claims.