EP1138525B1 - Phosphorescent, printable media - Google Patents

Abstract

The invention relates to a phosphorescent material, comprising a support layer and a phosphorescent ink-receiving layer. Said material can be printed or inscribed using transfer methods for digital data, especially relating to images and text.

Description

The present invention relates to a phosphorescent Material by means of transfer systems respectively. Transfer method for digital data, in particular Pictures and texts, such as laser lettering and in particular Ink-jet printer, writable and printable. Such Transfer systems resp. Transfer methods or transfer technologies are subsequently used as digital image transfer systems respectively. method resp. technologies.

There are already coatings with phosphorescent Material known, e.g. Coatings for Textiles, bicycles etc. Such coatings increase the visibility of the corresponding coated objects in the dark. They are usually printed such as screen printing, etc. applied.

The phosphorescent layers of the state The technique, however, have several disadvantages. Because the phosphorescent materials under light irradiation show only low intrinsic color, their contrast is on light background, e.g. by day or in a well-lit Space, very low. In addition, such layers usually applied by screen printing, i. every "motif" needs a corresponding template. at Combination of phosphorescent materials with conventional Colors, while eliminating the disadvantage of poor contrast on a light background with light irradiation, the application different colors but requires a corresponding Number of print templates.

Become phosphorescent layers alone e.g. Applied to a bright T-shirt, they are at Hard to see for days. Such a T-shirt has little appeal for people who are not alone in the dark well visible picture resp. a visible lettering on want to have her t-shirt. Furthermore, due to the previous used a custom design not or only very limited possible. individual Design of e.g. T-shirts are in high demand. materials and methods of customization and Production of T-shirts are known, e.g. from EP 0 850 786. These state of the art T-shirts are in the Do not darken visible.

Even with labels that hints in the dark are to give, are the previous labeling process only limited suitable, since the production of stencils is only worthwhile for large numbers, so that individually optimized labeling barely possible or very expensive.

EP 1 031 432 discloses a personal computer Printable material known, which is a carrier layer, a phosphorescent layer and a dye receiving layer includes, wherein the phosphorescent Layer does not serve the color photograph. Because only the ink-receiving layer suitable for color absorption and the phosphorescent Layer through the ink receiving layer therethrough must remain visible, is the thickness of this layer and their degree of filling with non-transparent, porous solids limited.

The aim of the present invention was therefore to one with digital printing process, resp. appropriate Techniques printable resp. writable improved To provide phosphorescent material.

This goal was achieved through the provision a phosphorescent material containing a Carrier layer and a color receiving layer, wherein the ink receiving layer porous solid particles and a Contains binder, and which is characterized that the ink receiving layer is also a phosphorescent Contains pigment.

Surprisingly, it was found that a Inventive material good ink receptivity and the phosphorescence of such a layer completely by the digitally applied color layer can be covered, which in the dark a clear Light and dark picture is created.

The ink receptive layer can be a homogeneous Be layer or of superimposed layers be constructed, wherein a partial layer, preferably the closer to the carrier located sublayer, the phosphorescent Contains pigment.

In order that the digitally applied image, for example a color image applied by means of laser or inkjet printing or inscription, is clearly imaged, ie shows good resolution, it is advantageous if the ink receptive layer comprises porous solid particles in a binder. Such porous particles are, for example, ceramic parts, such as zeolites, or plastic particles, whereby such particles can be obtained directly, or by subsequent reduction or agglomeration, by a special manufacturing process. Prefer porous particles are porous, solid thermoplastics. Preferably, such particles have a specific surface of> 6 m ² / g, in particular ≥ 20 m ² / g, a particle size of 0.1-40 .mu.m, in particular 5-15 .mu.m, and a melting temperature of <200 ° C. Especially preferred are thermoplastics such as the known under the name Orgasol products, in particular Orgasol® 3501 from eg Elf Atochem, Pouteaux, France with a particle diameter of about 10 microns and a surface area of about 25 m ² / g.

If e.g. Ceramic particles used, like Zeolite, these are preferably in combination with porous solid thermoplastics such as Orgasol® 3501 used.

Will the ink receptive layer of partial layers constructed, with 2 partial layers are preferred, so deep-melting porous particles are highly preferred since they become transparent when melting. Such porous Particles can either only be in a sublayer, preferably the sub-layer without phosphorescent Pigment, or be present in both partial layers.

For rapid color absorption is the presence porous particles in the layer facing away from the carrier prefers.

Suitable as phosphorescent pigment non-radioactive, long-phosphorescent pigments, such as they e.g. in EP 0 622 440 = US 5,424,006 and e.g. by Nemoto (Europe) B.V. in Amsterdam NL under available under the name LumiNova®. Be used usually in amounts of 5-60%, preferably in amounts of Quantities of about 35%. Such pigments phosphoresce in the generally at least 3 hours, often even 8 hours.

Additionally preferred is, if not only the Solid particles in the ink-receiving layer, but also the binder are porous. By such increased Porosity can be the local fluid intake, be it ink or pigment melt, increase, resulting in a better penetration of the entire layer with pigment and clear outlines. A method of manufacture a porous binder layer is e.g. from EP 0 850 786 known.

The binder may be a thermoplastic Resin, if necessary, after a single warming and activation is further networked or already complete crosslinked, thermosetting resin. The choice of suitable binder depends e.g. according to the purpose of the printed resp. labeled inventive Material.

Preferred binders, in particular for Transfer materials include polyvinyl alcohols, polyvinyl acetates, Polyvinylpyrrolidones, crosslinked, linear polyurethanes and especially preferably polyamides for which Transfer to e.g. Cotton T-shirts specially thermoplastics with melting point <200 ° C, in particular <140 ° C.

The ink receiving layer usually has a proportion of binder of 10 to 90 wt .-%, preferably 20-70 wt .-%, more preferably about 30 wt .-%, porous particles of 5 to 85 wt .-%, preferably about 35 wt .-% and phosphorescent pigment from 5 to 60 wt .-%, preferably about 35 wt .-% to. It is applied in amounts of (in the dried state) 5 to 80 g / m ² on the support.

The inventive phosphorescent Materials include transfer layers, e.g. for the Transmission of images, i. the color-receiving layer, on a substrate. Such substrates are e.g. Fabric, knitted fabric, Nonwovens, especially textiles like T-shirts, but Also items such as doors, bicycles etc. In addition to the Transfer layers comprise the inventive phosphorescent Materials also include "fixed" materials, i. Materials in which the ink receptive layer on the Carrier layer remains.

Fixed materials are relatively uncritical and can use a variety of different backing materials provided that their flexibility and the Adhesion of the ink-receiving layer for the implementation of the Printing method is sufficient. To increase liability may optionally be a surface treatment of the carrier or an adhesive layer between the backing and the ink receiving layer can be provided.

For fixed materials, the color-receiving layer is also especially the binder no further critical, as long as there is sufficient access to the porous Allowed solid particles. In addition to the color pigments If necessary, it may be advantageous to fix be, a e.g. thermally post-curing thermoplastic Use binders that melt when the further wetted with porous particles loaded with color pigments and at least partially "sealed". It lies Of course, in the context of this invention, the printed resp. labeled ink receiving layer by subsequent application of a cover, e.g. a foil, against mechanical damage, e.g. at Use as signs, such as floor inscriptions, fittings or keyboards designations etc.

Other applications put in the context of this Invention referred to as transfer materials materials advance, where at least the ink-receiving layer on a substrate, e.g. a textile, is transferred.

Non-phosphorescent transfer materials are known and described for example in EP 0 850 786. Such layer systems are basically also for the phosphorescent materials of this invention are suitable, provided they are porous in the ink receiving layer Contain solid particles, so that this layer with Phosphorescent pigment can be provided without that problems with only partial coverage of the Phosphorescence by the applied image resp. the angry Lettering is achieved. A "show through" The phosphorescence could be the clear statement of the dark visible image, in particular for important labels, e.g. emergency exits, could have undesirable consequences.

Such transfer materials must, in addition to the sufficient flexibility and the sufficient adhesion of the ink receiving layer to the carrier layer during printing resp. Labeling also have good transfer properties, ie, for example, good peelability of the carrier layer after heat treatment, eg ironing or hot lamination of the with the color receiving layer on a substrate, such as a textile, resting transfer material. This separation of carrier and ink-receiving layer can be improved, for example, by a release layer between carrier layer and ink-receiving layer, eg a silicone layer and / or a layer of a low-melting thermoplastic polymer, wherein such a release layer of a low-melting thermoplastic polymer at the same time a protective film on a substrate form transferred color receiving layer and can stabilize it. A release layer of a low melting thermoplastic polymer has a melting point which is about the melting point of the binder in the ink receiving layer. The release layer is usually applied in amounts of 5 to 50 g / m ² (based on dry matter).

A preferred carrier material for the transfer system is a one-side siliconized paper having a weight per unit area in the range of 50-150 g / m ² .

Preferably, they are transferred to a substrate Breathable layers, making these the wearer especially during exercise, such as cycling, Running, hiking, but also while dancing, do not interfere.

The phosphorescent ink-receptive layer Can be easily made by powdered phosphorescent pigment with the other components the ink receiving layer or a sub-layer of the ink receiving layer mixed and the resulting mixture to an optionally pretreated, resp. precoated Carrier applied by conventional methods becomes.

The use of phosphorescent materials The present invention is very versatile. As already mentioned, these can be used to signalize e.g. Emergency exits, fire extinguishers etc. are used, but also to designate operating systems whose safe operation is important or even in case of power failure is.

Another use is when Printed on textiles, especially in their individual design, where by the application of phosphorescent "White areas" in addition to the previous ones applied materials obtained aesthetic effect in a bright environment also an aesthetic effect in the dark or e.g. is achieved in a discotheque. simultaneously the carrier is added by the phosphorescence better visibility of bad light, which leads to it Safety, e.g. as a pedestrian on poorly lit Roads or paths, contributes.

The invention will now be described by way of examples explained in more detail.

Example: Used substances:

1. Preparation of a binder solution for a porous hotmelt layer: A polyamide, e.g. Elvamid, is in a mixture of water and ethanol or water and methanol dissolved. For the later dispersing of the microporous Particles and the phosphorescent pigment and stabilization the standing dispersion may additionally for organic fillers typical dispersing agent be stirred. The concentration of the polyamide in the Solution should be about 10 to 90 wt .-% and the mixing ratio Water / alcohol is adjusted that when brushing the viscous binder solution on a support and then drying at about 60-80 ° C form porous layers.

2. Microporous particles: polyamide powder, for example Orgasol® 3501 (particle size about 10 microns, specific surface area about 25 m ² / g).

3. Phosphorescent pigment: Non-radioactive, phosphorescent pigment in powder form, for example Luminova® G 300.

4. Diluent: Water / alcohol in the same mixing ratio as above.

5. Aqueous dispersion for applying the Hot melt layer (primer): A dispersion based on a sealable Ethylene-acrylic acid copolymer, for example a Enorex type with a solids content of approximately 40%.

Example 1 Production of a Transfer Film

In a first step, the dispersion for the hot-melt layer (release layer) is applied to the silicone side of a one-side siliconized release paper (120 g / m ² ) by means of a coating process, for example Reverseroll, and then dried at a temperature of approximately 110 ° C. The dry application should be about 30 g / m ² . In a second step, the dispersion for the porous hotmelt layer (ink receiving layer) is prepared. By means of an agitator, the binder solution (point 1) is stirred under dispersing conditions alternately portions of the polyamide powder (point 2), the phosphorescent pigment (point 3) and the diluent (point 4) until a creamy dispersion of suitable viscosity which can be coated with coating methods, eg reverseroll arises. Alternatively, the polyamide powder (item 2) and the phosphorescent pigment (item 3) can be mixed in advance and this mixture can be stirred in portions, alternately with the diluent (item 4). The dispersion for the porous hot-melt layer (ink-receiving layer) is now applied to the hot-melt layer (release layer / 1st step) by means of coating methods, for example Reverseroll, and dried at a temperature of approximately 60-110 ° C. The dry application should be about 30 g / m ² . The solids content of the binder based on the porous Hotmeltschicht is preferably about 30 wt .-%, the proportion of microporous particles at about 35 wt .-% and the proportion of phosphorescent pigment at about 35 wt .-%.

Such a layer has a good mechanical Stability and porosity and can be with digital Print and label image transfer systems well, but you can also with usual painting aids such as aqueous and solvent containing crayons, watercolors and wax crayons similar to ordinary paper to be painted.

The transfer to a substrate like white and Colorful cotton T-shirts come with the iron about 160 ° C to 200 ° C (heat level for cotton). The hotmelt material is printed with the resp. labeled Page placed against the shirt and to the desired Position positioned. The iron becomes the back of the paper thoroughly rubbed under heavy pressure, so that the color can merge with the layer and this connects to the fabric. When the hotter Paper back has cooled down a bit, the Abhäsivpapier deducted. Subsequently, several Washing processes in a washing machine with common detergents be performed. The phosphorescent pigment and the colors showed good washfastness.

Analogously, the transfer can also by means of hot laminator on e.g. a larger area textile, e.g. one Banner, done.

Example 2 : Preparation of a "fixed" material:

The procedure is as described in Example 1, wherein the dye-receiving layer is directly (without release layer) is applied to the carrier. There at a "fixed" material no transferability required is, the material used as a carrier needs none Separation promoting layer, e.g. one to this Purpose of using paper not to be siliconized rather - depending on the requirements - a bonding agent be used.

Claims (14)

1. Medium that is printable and inscribable by printing techniques for digital data or by inscribing techniques for digital data, respectively, and that has a support layer and a colour uptake layer comprising porous solid particles and a binder, characterised in that said colour uptake layer additionally comprises a phosphorescent pigment.
2. Medium according to claim 1, characterised in that the porous particles have a particle size of 5-40 µm, in particular 5-15 µm, and a surface of ≥ 20 m²/g.
3. Medium according to claim 1 or 2, characterised in that the colour uptake layer is a uniform layer.
4. Medium according to claim 1 or 2, characterised in that the colour uptake layer consists of at least two and preferably two partial layer.
5. Medium according to one of claims 2 to 4, characterised in that the porous particles are of thermoplastic material.
6. Medium according to claim 5, characterised in that the porous particles are of polyamide, have a mean diameter of about 10 µm and a surface of 25 m²/g.
7. Medium according to one of claims 1 to 6, characterised in that the binder is a thermoplastic binder.
8. Medium according to one of claims 1 to 7, characterised in that the binder is porous.
9. Medium according to one of claims 1 to 8, characterised in that the phosphorescent pigment is a non-radioactive pigment with at least 3 hours phosphorescence.
10. Medium according to one of claims 1 to 9, characterised in that between the support layer and the colour uptake layer it comprises a release layer melting at a temperature that is at most the softening temperature of the binder in the colour uptake layer.
11. Method for the production of a material according to one of claims 1 to 10, characterised in that the phosphorescent pigment is mixed with the other ingredients of the colour uptake layer or a partial layer thereof and is applied to the support layer optionally provided with a release layer.
12. Use of a medium of one of claims 1 to 10 as a mark.
13. Use of a medium of one of claims 1 to 10 for printing substrates.
14. Use according to claim 13, characterised in that the substrate is a woven fabric, knitted fabrics or non-woven material, in particular a textile.