EP1925463A2

EP1925463A2 - Method for making photoluminescent products and photoluminescent products

Info

Publication number: EP1925463A2
Application number: EP20070022677
Authority: EP
Inventors: Franco Luca Beltrame
Original assignee: Lucedentro Srl
Current assignee: Lucedentro Srl
Priority date: 2006-11-22
Filing date: 2007-11-22
Publication date: 2008-05-28
Also published as: ITMO20060388A1

Abstract

Method for making photoluminescent products (1), comprising at least one melting phase of a vitreous matrix material (A), at least one application phase of a photoluminescent pigment (B) on at least one portion of the outer surface of the vitreous matrix material, following the melting phase, and at least one forming phase by pressing of the vitreous matrix material, following the application phase, and suitable for the at least partial penetration of the photoluminescent pigment inside the vitreous matrix material for obtaining at least one photoluminescent product (1).

Description

The present invention relates to a method for making photoluminescent products and to the photoluminescent product thus obtainable.
For some time now, the use has been known of products such as tiles or the like of different shapes, dimensions and colours for covering walls, floors, etc., or, more in general, for decorating interiors.
The use is further known of specific types of products having a photoluminescent pigment that makes them visible in case of limited lighting or in case of the absence of lighting.
These products find application, for example, in the manufacture of signs inside lowly-lit environments so as to allow better visibility and, consequently, greater user safety during movements.
In particular, these products can be arranged, for example, along a staircase, at or near the step tread, to allow identifying a reliable support on the part of a user during movement.
Alternatively, these products can be used for a purely decorative purpose, in particular to obtain a characteristic visual impact inside an environment in the partial or complete absence of lighting.
The known photoluminescent products are generally made starting with a vitreous matrix material or a substantially transparent polymer material, mixed with a photoluminescent pigment in powder, flake state, etc..
These known products and the relative manufacturing process are, however, susceptible of improvements.
More specifically, manufacture by means of mixing with vitreous or polymer material results in the photoluminescent pigment also being distributed in the inner portion of the product, along the entire thickness.
For this reason, the photoluminescent pigment must be used in considerable quantity to obtain a satisfactory visual effect in the absence of light and, in view of the far from negligible costs of such pigment, this seriously affects the final costs of the manufactured photoluminescent product.
The main aim of the present invention is to find out a method for making photoluminiscent products that allows to achieve the above mentioned improvements and therefore to make a photoluminiscent product at considerably lower costs.
Within this technical aim, another object of the present invention is to achieve the above mentioned improvements with a simple structure, of relatively easy implementation and effective operation, as well as safe to use.
The above objects are all achieved by this method for making photoluminescent products, comprising at least one melting phase of a vitreous matrix material, characterized in that it comprises at least one application phase of a photoluminescent pigment on at least one portion of the outer surface of said vitreous matrix material, following such melting phase, and at least one forming phase by pressing of said vitreous matrix material, following said application phase, and suitable for the at least partial penetration of said photoluminescent pigment inside said vitreous matrix material for obtaining at least one photoluminescent product.
The above objects are all further achieved by a photoluminescent product comprising a body made of vitreous matrix material and a photoluminescent pigment distributed inside at least one portion of said body, characterized in that said photoluminescent pigment is arranged close to the outer surface of said body.
Further characteristics and advantages of the present invention will appear more evident from the detailed description of a preferred but not exclusive embodiment of a method for making photoluminescent products and of the photoluminescent product thus obtainable, illustrated indicatively by way of non limiting example, in the attached drawings wherein:

figure 1 is a side view schematically showing an application phase of a photoluminescent pigment of the method according to the invention;
figure 2 is a side view schematically showing a forming phase by pressing of the method according to the invention;
figure 3 is a side view schematically showing the photoluminescent product according to the invention;
figure 4 is a side view schematically showing the photoluminescent product according to the invention with a surface layer of fixing material.

With particular reference to the above illustrations, by 1 has been globally indicated a photoluminescent product, of the type of a tile, of a mosaic tessera or the like, made using the method according to the invention.
The photoluminescent product I comprises a body 2 made using a vitreous matrix material, indicated in the above illustrations with the reference A, and a photoluminescent pigment B distributed inside at least one portion of the body 2 and arranged close to the outer surface 2a of the body 2.
Usefully, the photoluminescent pigment B can have different grain size and, in particular, can be in powder, flake state, etc.
The body 2 can be substantially plate shaped and the photoluminescent pigment
B can be distributed on the entire outer surface 2a of the body 2.
Alternatively, the photoluminescent pigment B can be distributed only on the surface portion of the body 2 that remains visible after the installation of the photoluminescent product 1.
Different shapes of the body 2 and a different distribution of the photoluminescent pigments B to define a specific design or decoration cannot however be ruled out.
Advantageously, the photoluminescent product 1 can comprise a layer 3 of substantially transparent fixing material distributed on the outer surface 2a of the body 2. The layer 3 is suitable for making the photoluminescent product 1 substantially waterproof and for also allowing the fixing to the body 2 of the photoluminescent pigments 2 closest to the outer surface 2a.
The method for making the photoluminescent product 1 comprises a first preparation phase of a predetermined quantity of vitreous matrix material A.
The vitreous matrix material A is then placed inside a kiln and brought to melting temperature to obtain a substantially uniform body 2.
Subsequently, the method comprises a phase of gradual cooling of the body 2, during which the internal kiln temperature is read.
The temperature can be read by means of a suitable sensor device such as, for example, an optical temperature reader positioned close to the kiln exit.
When the temperature read is between 1000°C and 1100°C, a photoluminescent pigment B is applied on at least one portion of the outer surface 2a of the body 2.
Advantageously, the photoluminescent pigment B can have a grain size between 45x10^-6 m and 450x10^-6 m and, in particular, can be used in the form of powders, flakes, etc.
In particular, the manufacture of a photoluminescent product 1 with optimum aesthetic characteristics calls for the use of a photoluminescent pigment B with grain size between 200x10^-6 m and 300x10^-6 m.
The above application phase can be performed, for example, by bringing the outer surface 2a of the melted body 2 into direct contact with the photoluminescent pigment B distributed on a flat surface.
Alternatively, the photoluminescent pigment B can be distributed by gravity on the outer surface 2a. Different methods of application of the photoluminescent pigment B cannot however be ruled out.
Usefully, the photoluminescent pigment B can be distributed in a substantially uniform way on the entire outer surface 2a of the body 2. Alternatively, the photoluminescent pigment B can be localised inside a predetermined area of the outer surface 2a or, again, it can be distributed to delineate a predefined design or decoration.
Afterwards, the body 2 with the photoluminescent pigment B thus applied is placed inside a mould and is formed by means of one or more presses P to obtain at least one photoluminescent product 1.
During this pressing operation, the photoluminescent pigment B penetrates at least partially inside the vitreous matrix material A, through the outer surface 2a.
By means of pressing, a photoluminescent product 1 can, for example, be made of the type of a tile, of a mosaic tessera or the like, the body 2 of which has a substantially plate shape, and in which the photoluminescent pigment B is distributed on the flat faces opposite the body 2. The use cannot however be ruled out of different types of moulds and presses P suitable for making vitreous matrix photoluminescent products I of different shapes.
After pressing, the photoluminescent product 1 thus obtained can undergo a tempering phase suitable for upgrading the intrinsic hardness and strength properties.
Finishing operations of the photoluminescent product 1 can also be performed, such as grinding, sandblasting or tumbling operations of the outer surface 2a.
Usefully, a last distribution phase of a layer 3 of substantially transparent fixing material on the outer surface 2a, permits waterproofing the photoluminescent product 1 and the fixing of those photoluminescent pigments B closest to the outer surface 2a as well.
It has in fact been found how the described method achieves the proposed improvements, and in particular, the fact is underlined that such method allows making photoluminescent products with considerably lower costs.
In fact, the photoluminescent pigment is only distributed close to the outer surface of the body in vitreous matrix material. This therefore allows the use of a smaller quantity of the photoluminescent pigment compared to known methods that imply the mixing and uniform distribution of the pigment inside the body in vitreous matrix material.
The distribution of the pigment on the outer surface at the same time ensures a satisfactory visual effect in the absence of light; visual effect that does not in any case differ significantly from the effect achieved by means of the known products.
The described method furthermore allows overcoming the problems tied to the partial loss of the photoluminescent effect of the pigment if this undergoes the high temperatures needed to melt glass. In fact, the application of the photoluminescent pigment is done after the melting and the partial cooling of the vitreous matrix material.
The invention thus conceived is susceptible to numerous modifications and variations, all of which falling within the scope of the inventive concept.
Furthermore all the details can be replaced with others that are technically equivalent.
In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements without because of this moving outside the protection scope of the following claims.

Claims

Method for making photoluminescent products, comprising at least one melting phase of a vitreous matrix material, characterized in that it comprises:
- at least one application phase of a photoluminescent pigment on at least one portion of the outer surface of said vitreous matrix material, following such melting phase;

- at least one forming phase by pressing of said vitreous matrix material, following said application phase, and suitable for the at least partial penetration of said photoluminescent pigment inside said vitreous matrix material for obtaining at least one photoluminescent product.
Method according to claim 1, characterised in that it comprises at least one phase of gradual cooling of said vitreous matrix material, following such melting phase and before said application phase of said photoluminescent pigment.
Method according to one or more of the preceding claims, characterised in that it comprises at least one reading phase of the temperature of said vitreous matrix material during said cooling phase.
Method according to one or more of the preceding claims, characterised in that the maximum temperature of said vitreous matrix material during said application phase is comprised between 1000°C and 1100°C.
Method according to one or more of the preceding claims, characterised in that said photoluminescent pigment is at least partially in the state of incoherent particles of grain size comprised between 45x10^-6 m and 450x10^-6 m.
Method according to one or more of the preceding claims, characterised in that said photoluminescent pigment is at least partially in the state of incoherent particles of grain size comprised between 200x10^-6 m and 300x10^-6 m.
Method according to one or more of the preceding claims, characterised in that said pigment is at least partially in the powder state.
Method according to one or more of the preceding claims, characterised in that said photoluminescent pigment is at least partially in the flake state.
Method according to one or more of the preceding claims, characterised in that during said pressing phase said vitreous matrix material is placed inside a mould.
Method according to one or more af the preceding claims, characterised in that it comprises a distribution phase of at least one layer of fixing material on at least one portion of the surface of said photoluminescent product.
Method according to one or more of the preceding claims, characterised in that said fixing material is substantially transparent.
Method according to one or more of the preceding claims, characterised in that said layer of fixing material is substantially waterproof.
Method according to one or more of the preceding claims, characterised in that it comprises at least one tempering phase of said photoluminescent product.
Method according to one or more of the preceding claims, characterised in that it comprises at least one grinding phase of at least one surface portion of said photoluminescent product.
Method according to one or more of the preceding claims, characterised in that it comprises at least one tumbling phase of said photoluminescent product.
Method according to one or more of the preceding claims, characterised in that it comprises at least one sandblasting phase of at least one surface portion of said photoluminescent product.
Photoluminescent product, comprising a body made of vitreous matrix material and a photoluminescent pigment distributed inside at least one portion of said body, characterized in that said photoluminescent pigment is arranged close to the outer surface of said body.
Product according to claim 17, characterized in that said photoluminescent pigment is at least partially in the state of incoherent particles of grain size comprised between 45x10^-6 m and 450x10^-6 m.
Product according to one or more of the claims 17 and 18, characterized in that said photoluminescent pigment is at least partially in the state of incoherent particles of grain size comprised between 200x10^-6 m and 300x10^-6 in.
Product according to one or more of the claims from 17 to 19, characterised in that said photoluminescent pigment is at least partially in the powder state or the like.
Product according to one or more of the claims from 17 to 20, characterised in that said photoluminescent pigment is at least partially in the flake state or the like.
Product according to one or more of the claims from 17 to 21, characterised in that it comprises at least one layer of fixing material distributed on at least one portion of the outer surface of said body.
Product according to one or more of the claims from 17 to 22, characterised in that said fixing material is substantially transparent.
Product according to one or more of the claims from 17 to 23, characterised in that said layer of fixing material is substantially waterproof.
Product according to one or more of the claims from 17 to 24, characterised in that said body is substantially plate shaped.
Product according to one or more of the claims from 17 to 25, characterised in that said photoluminescent pigment is distributed close to the entire outer surface by at least one of the sides of said body.
Product according to one or more of the claims from 17 to 26, characterised in that it is a tile or the like.
Product according to one or more of the claims from 17 to 27, characterised in that it is a mosaic tessera.