GB2143180A - Transfers - Google Patents

Abstract

A method of producing a transfer for clothing or the like for application using a heat press, comprises printing a heat-transfer ink onto a silicone coated backing sheet. A heat-fusible synthetic resin, for example a polyester, is incorporated into the heat-transfer ink layer prior to and/or after its application to the backing sheet. The transfer is sintered to improve storage life.

Description

SPECIFICATION Transfer This invention relates to transfers, and in particular to transfers of the kind commonly used on garments which are applied using a heat-press.

A number of different forms of such transfers are known, for example "plastisol" transfers, and "flock" transfers. In plastisol transfers, a heat-transfer ink is provided on a layer of a release-coated backing sheet, for example a sheet of silicone-coated vegetable parchment by a printing process, for example a silkscreen or lithographic process. Heat-transfer inks are well known in the art, and typically comprise a PVC/acetate copolymer (plastisol), a plasticiser for the acetate copolymer, and various diluents and pigments. On heating in contact with a fabric material, such inks are caused to transfer to the fabric material, to give rise to the desired image on the fabric.

Plastisol transfers of this kind are generally satisfactory for use on fabrics made of natural fibres, and on some synthetic fibre blend fabrics, but are rather unsatisfactory when used on certain sorts of synthetic fibre fabrics, for example those of the kind now commonly used for sportswear, particularly when the fabric is closely woven. Adhesion to such fabrics is generally found to be unsatisfactory.

So-called "flock" transfers are made by a slightly different method, in which a backing sheet is first coated over all of one its surfaces with an adhesive, and a flock material, suitable for producing the desired "furred" effect in the final transfer is thereby cause to adhere to the backing sheet. Regions of the flock coating which it is desired should adhere to the fabric in the final transfer process are then provided with a coating of a barrier paste.

Whilst the paste image is still wet, a layer of heat-fusible synthetic resin material, for example a polyester or a polyamide, is sprinkled over the wet image. Excess synthetic resin is removed, and the resulting product sintered, for example at 150 to 200"C to fix the synthetic resin in place.

Because of the nature of the flock transfer production process, it is not possible by this method to produce the sort of complex multicoloured images which are possible using plastisols.

According to the invention, there is provided a method of producing a transfer, which method comprises providing a backing sheet, at least one surface of which includes a release material, and providing on at least a region of the said surface a heat-transfer ink comprising a particulate, heat-fusible synthetic resin material, for example a polyester or a polyamide.

The heat fusible resin is preferably a polyester, and may be incorporated, where the method used to apply the ink to the backing sheet allows, prior to the application of the ink to the backing sheet. Thus, a preferred method of incorporating the heat-fusible resin is to silk-screen print a heat-transfer ink layer, incorporating the particulate heat-fusible resin material, on to a backing sheet.

Alternatively, or additionally, the particulate heat-fusible synthetic resin material may be introduced into the heat-transfer ink layer by providing a layer of the particulate heat-fusible resin on the ink, for example by sprinkling the material on to the ink whilst the ink is still wet. This method may be used to advantage when an image is produced on the backing sheet by a lithographic printing process. Sintering, for example at a temperature of from 150 to 200"C for a period of 0.5 to 20 minutes, is preferably carried out when such a layer is provided.

The heat-fusible synthetic resin is preferably present uin the ink in an amount of from 5 to 25% by weight.

Incorporation of a resin as described above results in substantially improved adhesion to many synthetic resin fabrics, especially nylon fabrics. We have also found that the incorporation of the resin material significantly improves abrasion and the like resistance of the resulting transfer, on all fabric materials.

Particularly at higher levels of incorporation of the heat-fusible synthetic resin material, there is a tendency of the transfer to form a film on the final fabric, which may not be as flexible as the fabric to which the transfer is adhered, and therefore may tend to peel when the fabric stretches. In order to combat this tendency, it is preferable to incorporate a plasticiser for the heat-fusible synthetic resin.

A particulate plasticiser material may be used, and this may be mixed with the heat-fusible resin before it is employed. The plasticiser is preferably incorporated in an amount of from 1 to 2% by weight, based on the amount of the synthetic resin.

The invention is illustrated in the following examples: EXAMPLE 1 15% by weight of a polyester powder having a particle size of 3 microns was incorporated into a standard pigmented heat-transfer ink incorporating a PVC/acetate copolymer (a plastisol), diluent, and pigment. The resulting ink was applied to a silicone-coated vegetable parchment backing sheet using a silk-screen process. Whiist the ink was still wet, an amount of the same polyester powder material was sprinkled onto the ink surface, and excess powder was removed. The transfer was then sintered at a temperature of 150 , for two minutes.

The resulting transfer was fused on to a nylon sports shirt using a heat-transfer press at a temperature of 1 75 C, and was found to produce an abrasion-resistant permanent transfer image.

EXAMPLE 2 A multi-coloured print was applied to a backing sheet as in Example 1, using a conventional lithographic printing process, and the print was allowed to dry. A plastisol heattransfer ink as used in Example 1 (i.e. incorporating a polyester powder) was then applied over the print, using a silk-screen process. A polyamide as used in Example 1 was sprinkled over the plastisol whilst the plastisol was still wet, and thereafter the transfer was sintered and fused, as in Example 1. Again, a fast and abrasion resistant transfer was obtained.

It will be appreciated that although in both of the above examples, the polyester powder is both incorporated in the plastisol before printing, and sprinkled over the plastisol before drying, in some circumstances it may be possible to omit one or other of these steps.

Claims (14)

1. A method of producing a transfer, which method comprises providing a backing sheet, at least one surface of which includes a releast material, and providing on at least a region of the said surface a heat-transfer ink comprising a particulate, heat-fusible synthetic resin material.

2. A method as claimed in Claim 1, wherein the heat-fusible resin is a polyester.

3. A method as claimed in Claim 1 or Claim 2, wherein the heat transfer ink incorporates the said synthetic resin material prior to the application of the ink to the backing sheet.

4. A method as claimed in any one of Claims 1 to 3, wherein the ink is applied to the backing sheet by a silk-screen process.

5. A method as claimed in any one of the preceding claims wherein an ink is first applied to the backing sheet using a lithographic process and the heat transfer ink is then applied to the lithographic print.

6. A method as claimed in any one of the preceding claims, wherein a layer of the heatfusible synthetic resin material is applied to the heat-transfer ink after application of the heat-transfer ink to the backing sheet.

7. A method as claimed in Claim 6, and including the step of sintering after application of the said layer.

8. A method as claimed in Claim 7, wherein the sintering is carried out at a temperature of from 150 to 200"C for a period of from 5 to 20 minutes.

9. A method as claimed in any one of the preceding claims wherein the heat-fusible synthetic resin is present in the ink in an amount of from 2 to 25% by weight.

10. A method as claimed in any one of the preceding claims, wherein the ink also comprises a plasticiser for the heat-fusible synthetic resin.

11. A method of producing a transfer, substantially as hereinbefore described with reference to the foregoing specific Examples.

12. A transfer produced by a method as claimed in any one of the preceding claims.

1 3. An article comprising a fabric to which a transfer as claimed in Claim 1 2 has been applied using a heat press.

14. An article as claimed in Claim 13, wherein the fabric is a closely-woven synthetic fabric.