GB2040808A

GB2040808A - Flexible sheet material with transferable print

Info

Publication number: GB2040808A
Application number: GB7903320A
Authority: GB
Original assignee: TRANSPARENT PAPER Ltd
Current assignee: TRANSPARENT PAPER Ltd
Priority date: 1979-01-31
Filing date: 1979-01-31
Publication date: 1980-09-03
Also published as: GB2040808B

Abstract

A sheet material comprises a flexible substrate which has at least a non-porous surface, and which may be used as a protective wrapping. The surface carries printed matter which can be transferred to a second surface and which comprises polyvinyl- pyrrolidone as a film-former. In a particular embodiment the flexible substrate is a moistureproofed regenerated cellulose film coated on one side with an all-over print of a conventional white nitrocellulose-based ink. The transferable printed matter is printed from inks which comprise said film-former in ethanolic solution with an anionic wetting agent together with food-grade dyestuffs, and is covered with an overlacquer of colourless ink as a scuff-resistant and glossy protective cover. A use for this embodiment is as a wrapping or envelope for a lollipop or other item popular with children. Transfer of printed matter may be achieved by moistening the second surface, for example the back of the hand, with aqueous liquid, for example saliva, and pressing the printed matter into contact with the moistened second surface.

Description

SPECIFICATION Flexible sheet material with transferable print This invention relates to printed flexible sheet material from which the printed matter can be transferred to a second surface.

Transferable printed matter has long been known as a childrens toy or amusement device and comprises a porous substrate, such as for example fibrous paper. The substrate is first provided with a colourless transparent water-soluble all-overcoat- ing, on which is then printed non water-soluble transferable matter in one or more colours. Upon soaking such a structure in water and placing the wetted sheet in such manner that the printed transferable matter contacts a second surface - often the skin of the back of the hand or forearm - the water-soluble layer tends to dissolve and becomes in effect a release coating, so that, when the porous substrate is removed, the printed matter is released therefrom and is left on the second surface as a mirror image of the original.

Whilst such a printed structure gave pleasure to children, it was sold solely on its merits as a so-called "transfer", and has no further usefulness such as the capability to be used as a protective wrapping material.

According to the present invention there is provided a sheet material, wherein the sheet material comprises a flexible substrate carrying printed matter which can be transferred to a second surface, and which may also be used as a protective wrapping, and wherein the printed matter comprises polyviny Ipyrrolidone as a film-former.

A particularly apt use for the present sheet material is as a wrapping or envelope for a lollipop or other item popular with children.

The transference of the printed matter of the present sheet material is simpler and quicker than was the case with the old transfers, and is achieved by moistening the second surface with water, saliva or other aqueous liquid, pressing the printed matter into close contact with the moistened second surface, and then removing the substrate, the operation usually taking only some four to five second to complete.

The present transfer sheet material may comprise any suitable flexible substrate having a non-porous surface. Thus, most of the common thermoplastic or cellulosicfilms used in the packaging industry are suitable flexible substrates and even fibrous paper may be employed if the relevant surface is rendered non-porous by a suitable water-insoluble all-over coating or ink. If regenerated cellulose film is used as the flexible substrate, it will usually be desirable to employ a moistureproofed grade, and the conventional films coated with the compositions based on vinylidene chloride copolymers are particularly useful. In the case where the flexible substrate is a plastics or cellulosic film which is transparent, it will be found advantageous to cover the relevant surface with an initial all-over opaque ink - usually white before printing thereon the transferable matter, to act as a background for the latter before its transference, e.g., when the sheet is still in use as a wrapper.

On such a suitable or suitably prepared surface the transferable matter is printed from inks which, as indicated above, are characterised in that the filmformer used in their manufacture comprises polyvinylpyrrolidone. This, together with a wetting agent may be dissolved in ethanoi and to the solution may be added suitable dyes and/or pigments. If foodgrade dyestuffs or lakes made therefrom are employed, the resulting dried inks will be of a very low order to toxicity. Whilst not essential, the abovedescribed alcoholic solution of film-former, uncoloured, may be used as an overlacquer, further to improve the gloss and scuff-resistance of the print.

The invention will now be illustrated by the following non-limiting Example.

In this Example, a flexible sheet material was produced by coating a film of moistureproofed regenerated cellulose film of the type known as MXXT grade, of 36.5 g/m2. substance, by the gravure process on one side with an all-over print of a conventional white nitrocellulose-based ink. A two colour black and red design was then printed over the which backing by conventional gravure means, the inks being prepared by grinding either 10 pbw of vegetable carbon black or 20 pbw of the red pigment Cl No. 16185 which is an amaranth dyestufflaked onto aluminium hydrate (both pigments being permitted colours for foods) into 80 pbw of a medium comprising: 36.5% polyvinylpyrrolidone, pharmaceutical grade K30, from GAF (Gt. Britain Ltd); 1.0% anionic wetting agent: "GAFAC" (RTM) grade L0/529 from GAF (Gt. Britain Ltd); 62.5% industrial methylated spirits.

Finally, an overlacquering step was accomplished by coating the printed design by the gravure process using the above medium alone, and drying.

The product was a glossy, scuff-resistant, printed, flexible sheet material of good appearance and resistance to the transmission of moisture vapour, and was suitable as a wrapping material for sweets and the like.

By moistening a smooth area of skin on e.g., the forearm, and pressing a so-prepared sheet material thereto with the overlacquer in contact with the skin, and then after five seconds or so removing the sheet material, it was found that the two colour design had released from the white backing-ink and was to be found as a mirror image on the forearm. The transferred print dried in a few seconds and remained on the skin even after light rubbing, although it could be removed easily by washing, e.g.

with cold water.

Claims

1. A sheet material, wherein the sheet material comprises a flexible substrate which has at least a non-porous surface and which may be used as a protective wrapping, said surface carrying printed matter which can be transferred to a second surface and which comprises polyvinylpyrrolidone as a film-former.

2. A sheet material as claimed in claim 1,where in the flexible substrate comprises a thermoplastic film or a moisture proof grade regenerated cellulose film.

3. A sheet material as claimed in claim 2, wherein the moisture proof grade regenerated cellulose film is coated with a composition based on vinylidene chloride copolymers.

4. A sheet material as claimed in claim 1, wherein the flexible substrate comprises fibrous paper rendered non-porous by a suitable water-insoluble all-over coating or ink.

5. A sheet material as claimed in any one of claims 1 to 3, wherein the surface of the flexible substrate carrying printed matter, carries also an all-over coating of opaque ink underneath said printed matter.

6. A sheet material as claimed in any one of the preceding claims, wherein the transferable printed matter is printed from inks which comprise said film-former in ethanolic solution with a wetting agent, together with dyes and/or pigments.

7. A sheet material as claimed in claim 6, wherein the flexible substrate carries an overlacquer covering said printed matter and comprising said film former in ethanolic solution with a wetting agent, as a scuff-resistant and glossy protective layer.

8. A sheet material as claimed in claim 6 or 7, wherein said dyes andior pigments are food-grade dyestuffs or lakes.

9. A sheet material substantially as hereinbefore described in the foregoing Example.