GB2320931A - Printing on a surface of an elastic plastics material, especially a PVC based computer mouse mat, involving firstly screen printing then transfer printing - Google Patents

Abstract

There is disclosed a method of printing on a surface of an elastic plastics material, comprising: screen printing a background ink or varnish; and transfer printing a colour image and/or text over the background ink or varnish. Preferably, the ink or varnish is continuous. This allows a customary coverseal to be dispensed with. In an alternative which uses less ink or varnish, that is printed in an array of dots. This method is particularly suitable for the printing of computer mouse mats, eg with promotional material, since (1) Screen printing is limited to the application of blocks of solid colour, it not being possible to produce graded photograph-like colour images; and (2) experiments have been conducted with printing the base layer of a mouse mat by transfer printing using a colour copier but a adhesion of the transfer ink to the base layer is not good, especially if the layer is stretched.

Description

PRINTING ON ELASTIC PLASTICS MATERIALS This invention relates to printing on elastic plastics materials.

The background to the invention will be described in relation to mouse mats. Other applications may readily occur to the reader.

Mouse mats conventionally have a base layer of foamed plastics material intended to provide a degree of resilience and to resist sliding on the work surface. The mats are commonly printed with promotional material and given away by businesses to existing or prospective customers or clients. In one form, the surface of the foamed plastics material is screen printed directly. This leaves a rather soft surface and soft edge compared with another form in which a PVC layer is underprinted then adhered to the base layer. The soft edge is more comfortable for the operator.

Screen printing is limited to the application of blocks of solid colour, it not being possible to produce graded photograph-like colour images. Experiments have been conducted with printing the base layer by transfer printing using a colour copier. Adhesion of the transfer ink to the base layer is not good, however, especially if the layer is stretched. To overcome this problem, a laminate has been formed by overlaying the base layer with a self adhesive transparent coverseal. This protects the image generally and especially resists stretching of the laminate.

Against this background, there is provided a method of printing on a surface of an elastic plastics material, comprising: screen printing a background ink or varnish; and transfer printing a colour image and/or text over the background ink or varnish (the method).

Preferably, the ink or varnish is continuous. This allows the coverseal to be dispensed with.

In an alternative which uses less ink or varnish that is printed in an array of dots. A self adhesive cover seal over the transfer printed surface may be necessary in this case.

Generally, the ink is white.

Advantageously the transfer printing step uses an impregnated type of transfer film which is less expensive than the experimental coated type transfer film.

Most preferably, the plastics material comprises a sheet of polyvinyl chloride having a non expanded skin providing an upper surface, which is not substantially tacky at room temperature, for operative engagement with the mouse and an expanded layer beneath said skin containing sufficient plasticiser that the bottom surface thereof is tacky at room temperature.

The non expanded skin provides a suitably high coefficient of friction, surprisingly, even when printed.

The expanded layer provides a degree of resilience which assists the operation of the mouse. The tack provided by the plasticiser improves the friction between the mat and the work surface on which it lies, especially when the works surface is glossy, a condition which normally lowers the coefficient of friction.

The sheet preferably has a thickness from 0.9 to 1.2 mm approximately.

The expanded layer preferably contains 48-68 parts by weight of polyvinyl chloride and 20-45 parts by weight of plasticisers as esters of phtalic acid with alcohols from C8 to C12.

The invention extends to a mouse mat made by a the method in combination with a mouse operatively connected to a computer.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a mouse mat embodying the invention; and Figure 2 is a cross section of the mouse mat shown in Figure 1.

Referring to the drawings, the mouse mat 2 is generally rectangular approximately 20 to 30 cm by 15 to 20 cm, having rounded corners. The mat is made from sheet polyvinyl chloride which is manufactured by poring a non expanded emulsion of polyvinyl chloride onto a surface having a release coating so as to form a to form a skin 4.

The release coated surface has a mat finish to impart a mat finish on the skin 4. The layer is partially cured in an oven and a layer of polyvinyl chloride emulsion is pored onto the skin 4 and oven-cured to form an expanded layer having a surface skin. The layer contains sufficient plasticiser that when it cures to form a resilient layer 6 the surface skin 8 is tacky. When the layer has cured the thickness of the sheet is approximately 0.9 to 1.2 mm.

An example of the composition by weight of the layer 6 is as follows: Base resin emulsion polyvinyl 48-68% chloride Plasticisers esters of phtalic acid 20-45% with alcohols from C8 to C12 Stabilisers and Organic Ba - Zn and < 2% Kickers /or K-Zn soaps in epoxidised soya-bean oil Fillers calcium carbonates, 3-20% silica Pigments organic and/or 0.5-5% inorganic pigments The quantity of plasticisers is sufficient to provide a tacky surface to the skin 8 of the mat at room temperature. Less plasticiser is provided in the layer 4 so that the surface is not tacky at room temperature but provides a surface which, having a mat finish, presents a high coefficient of friction to the mouse ball.

Example 1 The surface of the skin 4 is then screen printed with a continuous layer of white ink. The skin may be black or white. To provide good colour quality, the ink would need to be thicker if the skin 4 is black.

A colour image and/or text is then printed on the screen printed surface using a colour copier and impregnated type transfer film.

The image was sufficiently adhered to the base layer that a coverseal was not necessary. Stretching the mat moderately did not cause the image to flake off.

Example 2 A white skinned base layer was used and a varnish was applied in a continuous layer by screen printing.

Example 3 A matrix of white dots was screen printed on a white skinned base layer. A colour image and/or text was then printed on the screen printed surface using a colour copier.

The adherence of the transfer printed image was not so great as in example 1 and a transparent self adhesive coverseal was applied to protect it. There was greater adherence than is the case when no screen printing is applied enabling the use of impregnated type transfer film.

Claims (10)

1. A method of printing on a surface of an elastic plastics material, comprising: screen printing a background ink or varnish; and transfer printing a colour image and/or text over the background ink or varnish.

2. A method as claimed in claim 1, wherein the ink or varnish is continuous.

3. A method as claimed in claim 1, wherein the ink or varnish is printed in an array of dots.

4. A method as claimed in claim 3, including the step of applying a self adhesive cover seal over the transfer printed surface.

5. A method as claimed in any preceding claim, wherein the ink is white.

6. A method as claimed in any preceding claim, wherein the transfer printing step uses a impregnated type of transfer.

7. A method as claimed in any preceding claim, wherein the plastics material comprises a sheet of polyvinyl chloride having a non expanded skin providing an upper surface, which is not substantially tacky at room temperature, for operative engagement with the mouse and an expanded layer beneath said skin containing sufficient plasticiser that the bottom surface thereof is tacky at room temperature.

8. A method as claimed in claim 7, wherein the sheet has a thickness from 0.9 to 1.2 mm approximately.

9. A method as claimed in claim 7 or 8, wherein the expanded layer contains 48-68 parts by weight of polyvinyl chloride and 20-45 parts by weight of plasticisers as esters of phtalic acid with alcohols from C8 to C12.

10. A mouse mat made by a method as claimed in any preceding claim in combination with a mouse operatively connected to a computer.