GB2250713A

GB2250713A - Transfer of fused toner images

Info

Publication number: GB2250713A
Application number: GB9025678A
Authority: GB
Inventors: Colin Montague Gray; Keith Anthony Egan
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-11-26
Filing date: 1990-11-26
Publication date: 1992-06-17
Also published as: GB9025678D0

Abstract

A colour or black and white photocopied image fused on paper or plastics sheet migrates into the porous surface of a ceramic tile when pressed against toner solvent on the tile. Trichloroethane or xylene may form the solvent for toner fusing oil.

Description

Image Transfer Techniques This invention is directed at image transfer techniques, and especially to a method or process of forming an image on a substrate from a two-dimensional representation thereof. The invention has particular, but not exclusive application to the formation of images on solid substrates such as ceramics.

Many photographic image transfer techniques are well established, as are various processes using decal or direct transfer of imaging elements to a substrate. The present invention is directed at a technique which in its preferred embodiment, exploits aspects of both techniques. In a method according to the invention, a of the image to be applied to a porous substrate is first formed in fused toner on an intermediate element. The application method comprises the steps of applying a transfer fluid to the substrate, and offering the intermediate element up to the substrate with the image thereagainst. The element and substrate are then pressed together, whereby the transfer fluid breaks down the fused toner forming the image and allows the toner to migrate to the substrate to transfer the image thereto.

Because the image formed on the substrate will be the reverse of that formed on the intermediate element, in preferred processes of the invention it is a reverse image that is formed on the intermediate element.

The method of the invention will normally include the step of forming the image on the intermediate element.

This step can be a straightforward photocopying exercise, and the intermediate element with the image thereon may therefore conveniently be a photocopy of an original.

The intermediate image may be in black and white or in colour. As noted above, the image formed on the substrate will of course be the reverse of that formed on the intermediate. However, some modern photocopying machines are capable of printing "reverse" images, and this facility can be usefully exploited in the practice of the present invention.

The intermediate element can be formed in any suitable material, and plain or prepared paper is quite acceptable. However, it is sometimes desirable to use a plastics sheet as the intermediate element as a plastics sheet does not form such a powerful bond with the intermediate image. Such an intermediate sheet can be re-used, and are readily available. Transparent sheets are particularly preferred in this variant.

In the transfer of the image to the substrate, the transfer fluid breaks down the fused toner which then, in fluid form, migrates into the pores of the substrate.

The depth to which the toner penetrates the substrate will depend upon a number of factors including not only the physical characteristics of the substrate, but also the amount of transfer fluid used and the nature of the toner itself on the intermediate element. Preferred substrates used in methods of the invention are ceramics which permit significant penetration of the image, for example to a depth in excess of 100 microns.

The method of the invention may be used to form images on substrates of various shapes and sizes. While flat substrates are of course easier to handle, the intermediate element in the method of the invention can also be applied to curved surfaces. To do so requires more care, but because there are not specific time constraints or temperatures to work to, very good quality transfer can nevertheless be achieved. The invention is however particularly well adapted to the transfer of images to ceramic tiles, and the preferred substrate in this context is a biscuit tile; ie, one which had been fired but not glazed. An image can be transferred in toto to one tile, or be spread over a number of tiles, depending upon the ultimate effect required. Of course, the actual shape of the tile is entirely a matter of choice.

Once an image has been transferred to a ceramic substrate in accordance with the invention, the substrate is preferably then glazed to secure the image. Cold glazing is preferred.

The image on the intermediate element may be formed in a photocopying process and, as noted above, may be in black and white or in colour. Laser copying systems are preferred, and intermediate elements formed using a Canon 500 colour copier are particularly suited for use in methods of the invention. Images formed in photocopying systems typically comprise toner and fusing oil, and when an intermediate element bearing such an image is used in a method of the invention, the transfer fluid will comprise a solvent for the fusing oil. One suitable solvent for use in the present invention is based on trichloroethane; another is based on xylene.

However, the transfer fluid must of course be selected with reference to the toner on the intermediate element to ensure that satisfactory migration is accomplished.

Claims

1. A method of forming an image on a porous substrate wherein an image is formed in fused toner on an intermediate element, the method comprising the steps of applying a transfer fluid to the substrate; offering the intermediate element up to the substrate with the image thereagainst; and pressing the element against the substrate, whereby the transfer fluid breaks down the fused toner forming the image and allows the toner to migrate to the substrate to transfer the image thereto.

2. A method according to Claim 1 wherein the intermediate element with the image thereon is a photocopy of an original.

3. A method according to Claim 1 or Claim 2 including the step of forming the image on the intermediate element.

4. A method according to any preceding Claim wherein the image is in colour.

5. A method according to any preceding Claim wherein the substrate is solid.

6. A method according to Claim 5 wherein the substrate is a ceramic.

7. A method according to Claim 6 wherein the substrate is a biscuit tile.

8. A method according to Claim 6 or Claim 7 including the step of glazing the substrate after formation of the image thereon.

9. A method according to Claim 8 wherein the glazing comprises cold glazing.

10. A method according to any preceding Claim wherein the image on the intermediate element is formed of toner and fusing oil, and wherein the transfer fluid comprises a solvent for the fusing oil.

11. A method according to Claim 10 wherein the solvent is based on one of trichloroethane and xylene.