GB2231309A - Identification article - Google Patents

Abstract

An identification article comprises a core (6); at least one image bearing sheet (3) secured to the core; and an adhesively secured envelope (1) surrounding the core and the or each sheet. The image (5) on the sheet is formed by at least one diffusible dye. No adhesive (2) contacts the image (5) so as to prevent diffusion of the dye into the adhesive. In an alternative construction (Fig. 3) the adhesive layer (24) is devoid of adhesive in the area of the image (22). In a further alternative (Fig. 5) a transparent barrier layer (28) overlies the image (22). <IMAGE>

Description

IDENTIFICATION ARTICLE The invention relates to identification articles of the kind comprising a core; at least one image bearing sheet secured to the core; and an adhesively secured envelope surrounding the core and the or each sheet.

Such articles are hereinafter referred to as of the kind described.

Identification articles of the kind described are used to form passes and the like and typically comprise a paper sheet on which personalised inoormaticDJl re~ati IICç to the holder is provided. This information can include the holder's name and address, identification number, company name and the like. This information is normally applied by typing or writing. In addition, the holder may sign the paper sheet. Alternatively, the article may hold iirormation which identifies groups of people, eg airline passengers, or objects.

The paper sheet is tllen folded along its middle so that the personalised or other individualising information is facing outwards and a core to provide rigidity and coated on both sides with a heat activatable adhesive is then placed within the fold. The composite is placed within two sheets of adhesive-coated, transparent, ~biaxially orientated polyester film to provide an envelope and the components are then laminated under heat and pressure to bond adjacent layers together.

The dimensions of the polyester film allow a margin of a few millimeters around the paper so that the two sheets of polyester are adhered together around their edges as well as to the paper sheet. This secures the components within the envelope and gives a very durable, pouched construction. The adhesive on the polyester will generally be a polyurethane. The laminate is then cut or stamped to size to fcrm the identity card and issued to the bearer. In some cases, a photograph of the bearer could be affixed to the security printed colour layer prior to lamination.

A particular problem arises when the paper sheet is replaced by a layer on which the image is formed with mobile or diffusible dyes. For example, such images can be generated by the selective transfer of dyes from a transfer sheet onto the image bearing sheet under electronic control in accordance with stored, digital data by laser writing means, thermal printing heads and the like.

The problem with such images is that the dyes can migrate into the adhesive securing the envelope to the image bearing sheet leading to a blurring of the image which is clearly undesirable.

In accordance with the present invention, an identification article of the kind described is characterised in that the image is formed by at least one diffusible dye; and in that no adhesive contacts the image on the sheet.

We have devised an alternative form of article in which no adhesive contacts the image on the sheet. In this way, the problems of dye migration are avoided while advantage is taken of the provision of an envelope to achieve a secure article.

Although the image could face the envelope, this may not be secure. Preferably, therefore, the image is provided on the surface of the sheet facing the core; and the envelope is adhered to the opposite surface of the image bearing sheet.

In some cases, the image bearing sheet may not extend throughout the area of the core allowing the envelope to be secured to a marginal portion of the core.

Alternatively, the envelope may not be secured directly to the core but simply hold the core relatively stationary within it.

In a further alternative, those parts of the image bearing sheet which do not carry an image could be provided with an adhesive to secure the cover sheet to the core. For example, the adhesive may contact substantially the whole of the remaining portion of the surface of the image bearing sheet on which the image is provided. Typically, in this case, the adhesive will surround each image and be separated from the image by a border of up to 2 mm.

Typically, the image bearing sheet is formed from a single member folded around the core.

The image bearing sheet preferably comprises a transparent dye receptive plastics film such as PVC or polyester which may be treated with dye receptive coatings. The sheet may include security printing or this printing may be provided on the core itself or both.

In the case where security printing is provided on the image bearing sheet on the same side as the diffusible dye image, then that security printing should be thin se that good dye transfer is achieved.

The core material may be reflective or opaque and can include paper, plastics, or laminates, for example filied white paper, or white PVC sheet.

The envelope is preferably made from:transparent polyester film te which has been applied heat activatable adhesive such as a polyurethane adliesive. The envelope may be applied as two separate sheets or alternatively a sincffiJe sheet Tray be folded in two. Normally, as mentioned above, at the perimeter the envelope will be bonded directly to itself.

Some examples of identity cards according to the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is an exploded view of one example; Figure 9 is a cr(ss-sectnon ti1ough v second example; and, Figures 3 to 5 are similar, partial cross-sections through three further examples.

The identity card shown in Figure 1 comprises a white card core 6 around which is folded a transparent polymeric film 3 defining an image bearing layer. The film 3 bears security printing 4 and electronically imaged dyes 5 defining an image such as a signature or photo image characteristic of the holder of the article.

This image 5, which faces the core 6, may have been generated by the transfer of dyes from a transfer sheet using a laser of the type illustrated in EP-A-202811.

Examples of electronically controlled dye transfer techniques are described in PCT/GB89/01375.

An envelope is provided around the film 3 and core 6 and in this example the envelope is defined by a pair of outer transparent layers of polyester 1 with adhesive coatings 2. The composite shown in Figure 1 is laminated together and it will be seen that since the extent of the layers 1 is greater than that of the film 3, the layers 1 will be adhered together at their margins and thus secure the card core 6 and film 3 together.

It should be doted, however, that no adhesive is provided between the film 3 and the card core 6 so that the problem of dye migration into such an adhesive is avoided.

In the Figure 2 example, a pair of outer transparent layers of polyester 10 defining an envelope and bearing adhesive 11 are bonded to a transparent film 12 defining an image bearing layer and bearing security printing 13 on one side (produced using a lithographic process) and electronically placed dye images 14 on the other. A core 15 of white polyester is provided which on its surface 16 remote from the film 12 carries background security indicia. Once again it will be seen that no adhesive contacts the dye images 14.

In the two examples just described, no adhesive at all is provided between the surface of the sheet carrying the dye transfered image and the adjacent surface. It is not necessary, however, to create large areas which are free from adhesive. Security ie tamper resistance, of the article can be enhanced if the adhesive and dye images alternate. Thus for example the adhesive may be printed tc ieave a stres of vacant cells so that each letter in a name falls within an adhesive free cell.

Furthermore, additional security is achieved by providing adhesive between both sides of the image bearing sheet and the adjacent core and envelope. This can be seen for example in Figure 3 which illustrates part of a core 20 similar to the cores 6, 16 on which is provided a transparent, polymeric film 21 carrying a dye transferred image 22. The film 21 is bonded to the core 20 by an adhesive layer 23 which covers completely the interface between these two components. The film 21 is also adhered to an envelope 25 by adhesive 24. The adhesive 24 contacts those areas of the sheet 21 which do not carry a dye image 22 and is spaced slightly from each dye image by up ta irjn as can be seen in Figure 3.

Figure 4 illustrates the reverse situation to that of Figure 3 with the dye image 22 facing the core 20.

Adhesive 26 is provided throughout the region between the film 21 and the envelope 25 while adhesive 17 is provided selectively between the film 21 and the core 20 so as not to contact the dye images 22.

Another method for preventing contact between adhesive and the dye transferred image is to provide an additional, barrier layer. An example of this is shown in Figure 5 in which a thin, transparent polymer barrier layer 28 such as silicone resin is provided over the dye image 22 allowing adhesive 29 to be provided throughout the interface between the film 21 and the envelope 25.

The polymer coating 28 may be deposited on top of the irraged area 22 after imaging or preferably onto the adhesive 29 itself.

Claims (15)

1. An identification article comprising a core; at least one image bearing sheet secured to the core; and an adhesively secured envelope surrounding the core and the or each sheet characterised in that the image is formed by at least one diffusible dye; and in that no adhesive contacts the image on the sheet.

2. An article according to claim 1, wherein the image is provided on the surface of the sheet facing the core; and the envelope is adhered to the opposite surface of the image bearing sheet.

3. An article according to claim 1 or claim 2, wherein the image bearing sheet does not extend throughout the area of the core allowing the envelope to be secured to a marginal portion of the core.

4. An article according to claim 1 or claim 2, wherein the envelope is not secured directly to the core but holds the core relatively stationary within it.

5. An article according to any of the preceding claims, wherein adhesive contacts substantially the whole of the remaining portion of the surface of the image bearing sheet on which the image is provided.

6. An article according to any of the preceding claims, further comprising-a barrier layer covering the image to prevent adhesive contacting the image.

7. An article according to any of the preceding claims, wherein the image bearing sheet is formed from a single member folded around the core.

8. An article according to any of the preceding claims, wherein the image bearing sheet comprises a transparent dye receptive plastics film which can be treated with dye receptive coatings.

9. An article according to any of the preceding claims, wherein the envelope is made from transparent polyester film to which has been applied heat activatable adhesive.

10. An article according to any of the preceding claims, wherein the image is formed on the image bearing layer by dye transfer.

11. An article according to any of the preceding claims, wherein one or both of the core and image bearing layer also includes security printing.

12. An article according to any of the preceding claims, wherein the image is characteristic of the article holder.

13. An article according to claim 12, wherein the image includes a photoimage of the holder.

14. An article according to any of the preceding claims, wherein the image is multi-coloured.

15. An identification article substantially as hereinbefore described with reference to the accompanying drawings.