WO2001072532A1

WO2001072532A1 - Phosphorescent material which can be printed with a transfer system for digital data

Info

Publication number: WO2001072532A1
Application number: PCT/IB2001/000403
Authority: WO
Inventors: Toni Bunschi
Original assignee: Celfa Ag
Priority date: 2000-03-30
Filing date: 2001-03-19
Publication date: 2001-10-04
Also published as: EP1138525B1; EP1138525A1; ATE303907T1; AU3947501A; DE50011111D1

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

Phosphorescent material that can be printed with a transfer system for digital data

Reference to related applications

This application claims priority from European Patent Application No. 00 107 002.8, filed on March 30, 2000, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present invention relates to a phosphorescent material that resp. By means of transfer systems. Transfer method for digital data, in particular images and texts, such as laser lettering and in particular ink et printer, can be written on and printed on. Such transfer systems, respectively. Transfer processes or transfer technologies are subsequently called digital image transfer systems or -Procedure -technologies.

State of the art

Coatings with phosphorescent material are already known, e.g. Coatings for textiles, bicycles etc. Such coatings increase the visibility of the correspondingly coated objects in the dark. They are usually applied using printing processes such as screen printing, etc.

However, the phosphorescent layers of the prior art have various disadvantages. Since the phosphorescent materials show only a small intrinsic color when exposed to light, their contrast is on a light background, for example during the day or in a well- lit room, very low. In addition, such layers are usually applied using the screen printing process, ie each “motif” needs an appropriate template. When phosphorescent materials are combined with common colors, the disadvantage of poor contrast on a light background when exposed to light is eliminated, but the application of different colors requires a corresponding number of printing templates.

Are phosphorescent layers alone e.g. applied to a light T-shirt, so you can hardly see them during the day. Such a t-shirt has little attraction for people who do not alone a picture that is clearly visible in the dark resp. want a visible lettering on their t-shirt. Furthermore, individual design is not possible or is possible only to a very limited extent due to the previously used application methods. Individual design of e.g. T-shirts are in high demand. Materials and processes for the individual design and manufacture of T-shirts are known, e.g. from EP 0 850 786. However, these state-of-the-art T-shirts are not visible in the dark.

Even for inscriptions that are intended to provide information in the dark, the previous inscription methods are only suitable to a limited extent, since the production of stencils is only worthwhile for large quantities, so that individually optimized inscription is hardly possible or very expensive.

The aim of the present invention was therefore to use a digital printing process, respectively. corresponding techniques printable resp. to provide writable phosphorescent material.

Presentation of the invention

This goal has been achieved by providing a phosphorescent material that is a Carrier layer and an ink-receiving layer and which is characterized in that the ink-receiving layer contains a phosphorescent pigment.

Surprisingly, it was found that a material according to the invention has good ink absorption capacity and the phosphorescence of such a layer can be completely covered by the digitally applied color layer, as a result of which a clear light-dark image is produced in the dark. The ink receiving layer can be a homogeneous

To be a layer or to be composed of layers one above the other, a partial layer, preferably the partial layer closer to the support, containing the phosphorescent pigment.

Ways of Carrying Out the Invention

So that the digitally applied image, for example a color image applied by means of laser or inkjet printing or lettering, is clearly depicted, ie shows a good resolution, it is advantageous if the ink-receiving layer comprises porous solid particles in a binder. Such porous. Particles are, for example, ceramic parts such as zeolites or plastic particles, such particles being able to be obtained directly by a special production process or by subsequent shrinking or agglomeration. Preferred porous particles are porous, solid thermoplastics. Such particles preferably have a specific surface area of> 6 μm / g, in particular> 20 μm / g, a particle size of 0.1-40 μm, in particular 5-15 μm, and a melting temperature of <200 ° C. Thermoplastics such as the products known under the name Orgasol are particularly preferred, in particular Orgasol® 3501 from, for example, Elf Atochem, Pouteaux, France, with a particle diameter of approximately 10 μm and a surface area of approximately 25 m 2 / g. If, for example, ceramic particles are used, such as zeolite, they are preferably used in combination with porous solid thermoplastics, such as Orgasol® 3501. If the ink-receiving layer is built up from partial layers, with two partial layers being preferred, deep-melting porous particles are strongly preferred since they become transparent when they are melted. Such porous particles can either be present only in one sub-layer, preferably the sub-layer without phosphorescent pigment, or in both sub-layers.

The presence of porous particles in the layer facing away from the support is preferred for rapid color absorption. Non-radioactive, long-phosphorescent pigments are suitable as the phosphorescent pigment, e.g. in EP 0 622 440 = US 5,424,006 and e.g. by Nemoto (Europe) B.V. are available in Amsterdam NL under the name LumiNova®. They are usually used in amounts of 5-60%, preferably in amounts of about 35%. Such pigments generally phosphoresce for at least 3 hours, often even up to 8 hours.

It is additionally preferred if not only the solid particles in the ink absorption layer but also the binder are porous. Such an increased porosity allows the local absorption of liquid, be it ink or pigment melt, to be increased, which leads to better penetration of the entire layer with pigment and clear contours. A method of making a porous binder layer is e.g. known from EP 0 850 786.

The binder can be a thermoplastic resin which, if appropriate after further heating and activation, cross-links further, or an already fully cross-linked, thermosetting resin. The choice of a suitable binder depends, for example, on the purpose of the printed resp. 'labeled material according to the invention.

Preferred binders, especially for transfer materials, include polyvinyl alcohols, polyvinyl acetates, polyvinyl pyrrolidones, cross-linked, linear polyurethanes and particularly preferably polyamides, for transfer to e.g. Cotton t-shirts, especially thermoplastics with melting point <200 ° C, especially <140 ° C.

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

The phosphorescent materials according to the invention comprise transfer layers, e.g. for the transmission of images, i.e. the ink receptive layer, on a substrate. Such substrates are e.g. Fabrics, knitted fabrics, nonwovens, in particular textiles such as T-shirts, but also objects such as doors, bicycles etc. In addition to the transfer layers, the phosphorescent materials according to the invention also comprise "fixed" materials, i.e. Materials in which the ink-receiving layer remains on the carrier layer.

Fixed materials are relatively uncritical and can have a variety of different substrates, provided that their flexibility and the adhesion of the ink-receptive layer are sufficient for the implementation of the printing process. To increase the adhesion, a surface treatment of the carrier or an adhesion promoter layer can optionally be provided between the carrier and the ink-receiving layer. In the case of fixed materials, the ink-receiving layer, in particular the binder, is also no longer critical, as long as there is sufficient access to the porous ones Solid particles allowed. In order to additionally fix the color pigments, it may be advantageous to use, for example, a thermally postcrosslinking thermoplastic binder which, when melted, further wets and at least partially "seals" the porous particles loaded with color pigments. It is of course also within the scope of this invention the printed resp. to secure the labeled ink absorption layer against mechanical damage by subsequently applying a cover, for example a foil, for example when used as signs, such as floor labels, fittings or keyboards, etc.

Other applications require materials referred to as transfer materials in the context of this invention, in which at least the ink-receiving layer is applied to a substrate, e.g. a textile that is transferred.

Non-phosphorescent transfer materials are known and are described, for example, in EP 0 850 786. Such layer systems are in principle also suitable for the phosphorescent materials of this invention, provided that they contain porous solid particles in the ink-receiving layer, so that this layer can be provided with phosphorescent pigment without problems with only partial coverage of the phosphorescence by the applied image or. the applied lettering is achieved. A "shining through" of the phosphorescence could impair the clear statement of the image visible in the dark, which is particularly the case with important labels, e.g. of emergency exits could have undesirable consequences.

Such transfer materials must have sufficient flexibility and sufficient adhesion of the ink-receptive layer to the support layer during printing or. Labeling also have good transfer properties, ie, for example, good removability of the carrier layer after heat treatment, for example ironing on or hot lamination of the one with the ink-receiving layer Substrate, for example a textile, transfer material lying on top. This separation of carrier and ink-receiving layer can be improved, for example, by a release layer between the carrier layer and ink-receiving layer, for example a silicone layer and / or a layer of a low-melting thermoplastic polymer, such a release layer of a low-melting thermoplastic polymer simultaneously providing a protective film over that on a substrate trained color recording layer and can stabilize this. A release layer made of a deep-melting thermoplastic polymer has a melting point which corresponds approximately to 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 ^ (based on dry matter).

A preferred carrier material for the transfer system is one-sided siliconized paper with a basis weight in the range of 50-150 g / m ^. The layers transferred to a substrate are preferably breathable, so that they do not adversely affect the wearer, in particular during sporting activities such as cycling, running, hiking, but also when dancing. The phosphorescent ink-receiving layer can be produced simply by mixing powdered phosphorescent pigment with the other components of the ink-receiving layer or a partial layer of the ink-receiving layer and the resulting mixture on an optionally pretreated or. precoated carrier is applied by the usual method.

The use of the phosphorescent materials of the present invention is very versatile. As already mentioned, these can be used to signal, for example, emergency exits, fire extinguishers etc., but also to designate operating systems, their Safe operation is important, especially in the event of a power failure.

Another possible use is in the printing of textiles, in particular in their individual design, where by applying phosphorescent "white areas" in addition to the aesthetic effect obtained in bright surroundings in the case of previously used materials, an aesthetic effect in the dark or e.g. is achieved in a discotheque. At the same time, the carrier is made more visible by the phosphorescence in poor light, which for its safety, e.g. as a pedestrian on poorly lit streets or paths.

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

For example:

Substances used:

1. Preparation of a Binder Solution for a Porous Hotmelt Layer:

A polyamide, for example elvamide, is dissolved in a mixture of water and ethanol or water and methanol. For the later dispersing in of the microporous particles and the phosphorescent pigment and stabilization of the standing dispersion, a dispersion aid typical of organic fillers can also be stirred in. The concentration of the polyamide in the solution should be about 10 to 90% by weight and the mixing ratio water / alcohol is adjusted in such a way that porous layers are formed when the viscous binder solution is spread onto a carrier and then dried at about 60-80 ° C. , 2. Microporous particles: polyamide powder, for example Orgasol 3501

(Grain 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 an Enorex type with a solids content of approximately 40%.

Example 1: Production of a transfer film:

In a first step, the coating for the hot melt layer (release layer) is applied to the silicone side of a one-sided siliconized adhesive paper (120 g / m ² ) by means of a coating process, for example reverse roll, and then dried at a temperature of approximately 110 ° C. The dry application should be approximately 30 g / m ² . In a second step, the dispersion is prepared for the porous hot melt layer (paint-on layer). Portions of the polyamide powder (point 2), the phosphorescent pigment (point 3) and the diluent (point 4) are alternately stirred into the binder solution (point 1) by means of a stirrer until dispersion has been achieved, until all of the dispersion can be coated with coating methods, for example Reverseroll suitable viscosity arises. Age- natively, the polyamide powder (point 2) and the phosphorescent pigment (point 3) can be mixed in advance and this mixture can be mixed in portions, alternating with the diluent (point 4). The dispersion for the porous hot-melt layer (ink-receptive layer) is then applied to the hot-melt layer (release layer / 1st step) by means of a coating process, for example reverse roll, 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 hot melt layer, is preferably around 30% by weight, the proportion of microporous particles is around 35% by weight and the proportion phosphorescent pigment at approx. 35% by weight. Such a layer has good mechanical stability and porosity and can be printed and labeled well with digital image transfer systems, but it can also be painted with conventional painting aids such as water-based and solvent-based crayons, water colors and wax crayons similar to ordinary paper.

The transfer to a substrate such as white and colorful cotton T-shirts is done with an iron at around 160 ° C to 200 ° C (heat setting for cotton). The hot melt material is printed with the labeled side against the T-shirt and positioned at the desired location. With the iron, the back of the paper is thoroughly brushed under vigorous pressure so that the color can melt with the layer and this connects to the fabric. When the hot paper back has cooled down a bit, the adhesive paper is removed. Then several washing processes can be carried out in a washing machine with common detergents. The phosphorescent pigment and the colors showed good wash fastness. Analogously, the transfer can also be carried out by means of a hot laminator to, for example, a large-area textile, for example a banner.

Example 2: Production of a "fixed" material

The procedure is as described in Example 1, the ink-receiving layer being applied directly (without a release layer) to the support. Since no transferability is required for a "fixed" material, the material used as a support need not have a layer which promotes separation, e.g. a paper used for this purpose is not siliconized, but - depending on the requirement - an adhesion promoter can be used.

Claims

claims

1. Using printing techniques resp. Labeling techniques for digital data, in particular data from pictures and texts, printable and labelable material with a carrier layer and an ink absorption layer which contains porous solid particles and a binder, characterized in that the ink absorption layer also contains a phosphorescent pigment.

2. Material according to claim 1, characterized in that the porous particles have a particle size of 5-40 μm, in particular 5-15 μm, and a surface area of> 20 m / g.

3. Material according to claim 1 or 2, characterized in that the ink absorption layer consist of a uniform layer.

4. Material according to claim 1 or 2, characterized in that the ink absorption layer consists of at least two and preferably two sub-layers.

5. Material according to one of claims 1 to

4, characterized in that the porous particles are made of thermoplastic material.

6. Material according to claim 5, characterized in that the porous particles are made of polyamide, have an average diameter of about 10 microns and a surface of 25 m / g.

7. Material according to any one of claims 1 to

6, characterized in that the binder is a thermoplastic binder.

8. Material according to one of claims 1 to

7, characterized in that the binder is porous.

9. Material according to one of claims 1 to

8, characterized in that the phosphorescent pigment is a non-radioactive pigment with at least 3

Hours of phosphorescence.

10. Material according to any one of claims 1 to 9, characterized in that it has a release layer between the carrier layer and the ink-receiving layer, which melts at a temperature which corresponds at most to the softening temperature of the binder in the ink-receiving layer.

11. A method for producing a material according to any one of claims 1 to 10, characterized in that the phosphorescent pigment is mixed with the other constituents of the ink-receiving layer or a partial layer thereof and is applied to the carrier layer optionally provided with a release layer.

12. Use of the material according to one of claims 1 to 10 as a marking.

13. Use of the material according to one of claims 1 to 10 for printing on substrates.

14. Use according to claim 13, characterized in that the substrate is a woven, knitted or nonwoven, in particular a textile.