GB2345067A - A pressure sensitive recording device - Google Patents

Abstract

A pressure sensitive recording device (10) comprises a layer (12) of micro-encapsulated material (13) and a layer (14) of a re-active substance, the two layers being located between two covers (11) and (15) and the arrangement being such that, when the layers (12, 14) are in contact one with another and the device is subjected to a non-planar pressure inducing stimulus, the micro-encapsulated material is released and reacts with the substance so that the substance is activated irreversibly thereby recording that the device has been subjected to the stimulus. Cover (15) may be transparent. The re-active substance in layer (14) is a moisture and oil sensitive substance and the re-active substance may also be present in microcapsule form. The pressure sensitive recording device may be incorporated in a closure or a container such as to indicate tamper evidence (Fig. 4 not shown) or in an improved lottery card.

Description

A PRESSURE SENSITIVE RECORDING DEVICE This invention relates to a pressure sensitive recording device.

It is known from US-A-5,433,214 to provide a substance which is receptive to contact with moisture and oil and the refractive index of which, after contact, changes in such a way that a partially or wholly covered image below the substance becomes visible. It is also known to provide paper carrying micro-encapsulated material which, when subjected to localised pressure, such as impact from an alphanumeric strike head of a printer, releases ink onto the sheet in the area of impact. The ink united with the paper provides an irreversible recording.

According to the present invention, there is provided a pressure sensitive recording device comprising a micro-encapsulated material and a re-active substance, the arrangement being such that when the micro-encapsulated material and the re-active substance are in contact one with another and subjected to a non-planar pressure inducing stimulus, the microencapsulated material is released and reacts with the substance so that the substance is activated irreversibly thereby recording that the device has been subjected to the stimulus.

Following is a description, by way of example only and with reference to the accompanying drawings, of one method of carrying the invention into effect.

In the drawings: Figure 1 is a diagrammatic cross-section of one embodiment of a device in accordance with the present invention, Figure 2 is a diagrammatic cross-section of another embodiment of a device in accordance with the present invention, Figure 3 is a diagrammatic perspective view of another embodiment of a device in accordance with the present invention, the device being in a non-active condition and being contained within a screw cap.

Figure 4 is a cross section of the cap shown in Figure 3, and Figure 5 is a view, corresponding to Figure 3, showing the device in an active condition.

Referring now to Figure 1 of the drawings, there is shown a device 10 comprising a substrate 11 carrying a layer 12 of micro-capsules 13 and superimposed on the layer 12 is an opaque layer 14 of moisture and oil sensitive substance. The layer 14 has superimposed thereon a transparent layer 15. Preferably, the substrate 11 and the top transparent layer 15 are of larger dimension than the intervening layers 12 and 14 and are sealed one to another along peripheral margins so that the layers 12 and 14 are encapsulated by the substrate 11 and the top transparent layer 15.

The arrangement is such that, when an upper surface of the top transparent layer 15 is rubbed with a finger nail or a stylus, the pressure exerted ruptures the micro-capsules 13 of the layer 12 and the encapsulant bleeds out into contact with the moisture and oil sensitive substance 14. The effect is that the released encapsulant reacts with the substance 14 so as progressively and irreversibly to change the opacity of the layer 14 so that the layer 14, which in a non-activated state occludes vision through the layer 14, in an activated state becomes see-through.

If the surface of the substrate 11 carrying the micro-capsules 13 is printed with information, this will become visible when the layer 14 becomes seethrough.

Alternatively, the material of the micro-capsules 13 may be of a contrasting colour and the view of this colour, when the layer 14 becomes see-through, may provide a signal. In yet another embodiment, only some of the microcapsules 13 are of a contrasting colour so as to form a sign, such as the word"WIN".

The primary purpose of the top transparent layer 15 is to provide a means of preventing premature activation of the material 14.

In the embodiment shown in Figure 2 of the drawings, the moisture and oil sensitive substance 14 is pre-coated on to the underside of the top transparent layer 15 and is brought into contact with the layer 12 of microcapsules 13 which has previously been deposited on the substrate 11. This resulting assembly is then be die cut or punched to shape.

The embodiments shown in Figures 1 and 2 provide a device which is abrasion resistant.

The layers 11 and 15 need not be united one to another to encapsulate the intervening layers 12 and 14 and the layer 15 need not be transparent. If the layers 11 and 15 were to comprise two panels of a folded card, when the two panels are folded so that the layer 12 of micro-capsules 13 is in contact with the layer 14 of re-active substance and an outer facing surface of the folded card is rubbed with a finger nail or a stylus in a region in register with the overlapping layers 12 and 14, the micro-capsules 13 will rupture and the encapsulant will bleed out into contact with the moisture and oil sensitive substance 14 and will re-act with it. This will result in an irreversible sign, such as a record of a word, eg"WIN", which will be visible when the card subsequently is opened out.

The effect can be achieved if, in the arrangement shown in Figure 2, the sheet 15, being non transparent, were to be a continuation of the sheet 11 which would be folded to provide the configuration shown in Figure 2.

Thus, a particular application of a device in accordance with the present invention is an improved lottery card which does not require material to be removed in order to reveal a previously obscured message.

Referring now to Figures 3 to 5 of the drawings, there is shown a screw cap 16 for closing a container 17 having a screw threaded neck 18.

The cap 16 includes a circumferential skirt 19 having an internal screw thread 20. The internal screw thread 20 is engageable with an external screw thread 21 of a skirt 22, of an inner cap 23, the skirt 22 of which is also provided with an internal screw thread 24. The internal screw thread 24 of the skirt 22 of the inner cap 23 is engageable with the screw threaded neck 18 of the container 17. The arrangement is such that the combination of the outer and inner caps 16,23 provides a child-proof closure in that the internal screw thread 20 of the external cap 16 and the external screw thread 21 of the inner cap 23 only engage one with another when a preliminary action is undertaken which will require application of pressure, for example applying opposing forces diametrically inwardly of the skirt 19, greater than can be applied by a child.

The skirt 19 of the outer cap 16 is provided with an elongate aperture 25 the longitudinal axis of which extends in a circumferential direction of the skirt 19. The internal screw thread 20 of the skirt 19 adjacent opposite ends 26,27 of the aperture 25 is provided with internal projections, one of which is shown at 28. The external screw thread 21 of the inner cap 23 is provided with an elongate recess 29 the longitudinal axis of which extends in a circumferential direction of the skirt 22 and is of greater dimension than the longitudinal axis of the aperture 25. The recess 29 has located therein the device 10, referred to above, in elongate form.

The arrangement is such that the device 10 located in the recess 29 is engaged by the projections 28 such that, if there is relative movement between the inner and outer caps 16,23 in a circumferential direction of the caps 16,23, as would be the situation if a child were to attempt to unscrew the outer cap 16 from the container 17, the projections 28 would apply pressure in a track extending longitudinally of the device 10 which would result in a signal being visible through the aperture 25 indicating tamper evidence.

Apart from the embodiments referred to above, a device in accordance with the present invention may also provide a means for recording information by locating the device relative to a percussive image recording head, such as a dot matrix printer, and operating the head to strike the device such that the moisture and oil sensitive layer 14 changes from a non-activated to an activated condition.

The encapsulant material may be processed separately in two parts where material of one group of capsules acts as a re-agent to material of another group of capsules and the two discrete groups of capsules containing these re-active materials are mixed and applied to the carrier substrate 11 such that a further colour change will occur when the micro-capsules 13 are subjected to rupture and admixture of the materials.

The encapsulant material, when processed in two parts if required, to form a reaction between the separate encapsulated particles, may be mixed together first and applied to one side of the substrate 11, or applied as separate reactive components, each to the surfaces 11 and 15.

Accordingly, a device can be manufactured in which the reactive surfaces are brought together in the form of a transparent and separate'viewfinder window'forming substrate 15 which is applied by the user over substrate 11 to activate the colour change, or applied on an extended adjacent area of layer 11, and this'page'either detached from itself at a pre-determined point or folded back over itself, registered together and activated by the user.

The micro-capsules 13 may comprise a material which is clear, singly or plurally coloured and transparent or opaque. Micro-encapsulation may be carried out as phase separation from aqueous solution or from organic solvent or suspension and coating in gas and spray drying. The microcapsules 13 may be processed in liquid form or in dry form as discrete core particles prior to application to carrier substrate 11. The micro-capsules 13 may be in liquid form or in dry form as discrete core particles.

Claims (13)

1. CLAIMS 1. A pressure sensitive recording device comprising a micro encapsulated material and a re-active substance, the arrangement being such that when the micro-encapsulated material and the re active substance are in contact one with another and subjected to a non-planar pressure inducing stimulus, the micro-encapsulated material is released and reacts with the substance so that the substance is activated irreversibly thereby recording that the device has been subjected to the stimulus.
2. 2. A device as claimed in Claim 1 wherein the micro-encapsulated material and the substance are located between two covers.
3. 3. A device as claimed in Claim 1. wherein the covers comprise substrates, one carrying the micro-encapsulated material and the other carrying the substance.
4. 4. A device according to Claim 2 or Claim 3 wherein at least one of the covers comprises a see-through layer.
5. 5. A device as claimed in any one of Claims 2 to 4 wherein the covers are of larger dimension than the micro-encapsulated material and the substance and are sealed one to another at peripheral margins so that the micro-encapsulated material and the substance are encapsulated by the covers.
6. 6. A device as claimed in any one of the preceding Claims wherein the device is incorporated in a closure of a container such as to indicate tamper evidence.
7. 7. A device as claimed in Claim 6 wherein the closure comprises a screw cap having an aperture and wherein the device is visible in the aperture.
8. 8. A device as claimed in Claim 7 wherein the cap is provided with means to engage the device and the arrangement is such that tamper evidence is effected when the cap is moved relative to the container in an attempt to open the container such that the said means moves relative to the device.
9. 9. A device as claimed in Claim 8 wherein the cap comprises an outer component and an inner component located for relevant movement one with another, the outer component being provided with the aperture and the said means and the inner component carrying the device.
10. 10. A device as claimed in any one of the preceding Claims wherein the re-active substance is also in micro-encapsulated form.
11. 11. A device as claimed in Claim 10 wherein the micro-capsules of the material and the micro-capsules of the substance are mixed one with another.
12. 12. A device as claimed in Claim 11 wherein the mixture of micro capsules is controlled to provide a visible sign when the material and the substance re-act one with another.
13. 13. A pressure sensitive recording device substantially as hereinbefore described and as illustrated in Figure 1 or Figure 2 or Figures 3 to 5 of the accompanying drawings.