The invention concerns a method of decorating textiles or other, preferably flexible, materials with patterns comprising highly light-reflecting areas defined by inked areas. The invention also relates to a combined plastisol reflex transfer for decorating textiles or other, preferably flexible, materials by application of heat.

It is known to decorate textiles by printing patterns in various colours by a suitable printing method, e.g. the silk screen process. For such patterns to be durable in use and to have good fastness to repeated washing, it is important that the inks used for the printing have good adhesion and cannot be peeled or picked off, that they are elastic so as to be capable of following the expansion and contraction of the substrate, and that they do not crackle or flake.

So-called plastisol inks have been developed for this purpose, based on elastomeric resins, often modified with polyvinyl chloride (PVC), dissolved in high-boiling organic solvents. These plastisol inks, which are also called gum printing inks, can be given all possible shades by pigmentation.

It is also known to produce so-called transfers by means of these plastisol inks, i.e. by printing a given pattern in mirror-inverted fashion on a suitable substrate, preferably silicone or wax treated paper. The pattern may then be transferred by the user, e.g. a textile factory, from such a transfer to the textile by application of heat, i.e. the transfer is placed with

the inked side against the textile and heated to 130 to 200°C, generally 160 to 180°C, under pressure with a pressure of 100 to 800 kPa, generally about 500 kPa, for 10 to 30 seconds, generally 15 to 20 seconds. The temperature, pressure and treatment time used depend, of course, upon the type and nature of the textile fabric and upon the plastisol type applied, but generally elevated temperatures will involve treatment for a shorter period of time, and vice versa.

It is also known to produce so-called retro-reflecting films with a great light reflecting capacity for appli¬ cation on e.g. textiles, first and foremost for security reasons. These retro-reflecting films or reflex films come in two main types, one with a very large number of fine glass beads with a high refractive index embedded with a reflecting substrate in a base sheet (glass bead type), and another formed with a large number of prisms in a sheet. Both types may be formed with the glass beads or the prisms exposed in the surface (open type) or enclosed in a transparent layer (semi-open type) or coated with an optionally inked layer (closed type), or finally encapsulated in closed cavities with entrapped air (capsule type) . The reflex films may be formed as reflex transfer films with a heat-activated adhesive intended for e.g. heat application to textiles. Reflex transfer films of the glass bead type may moreover be produced in a very elastic material, which makes them particularly suitable for application to flexible materials.

It would be a great advantage if the high reflectivity and consequent warning and attention-attraction value of the reflex films could be combined with the decoration and advertising purposes which it is attempted to achieve by printing of e.g. company names, trade marks, logos, slogans and decorative images on textiles with

plastisol inks.

However, it has till now been considered impossible to combine application of reflex films with printing of plastisol inks because the inks did not adhere to the reflex films, but peeled or rapidly flaked in use. . Therefore, where it was desired to apply patterns, e.g. letters, in reflex films, it has been necessary to resort to punching or cutting these from the transfer film and then applying the individual pieces separately, which is very cumbersome.

This problem is solved by the method of the invention, it having surprisingly been found possible to make plastisol inks adhere firmly to both reflex films and textiles, thus permitting production of durable patterns comprising highly light-reflecting areas defined by inked areas. Further, according to the invention, it has been found possible to provide combined plastisol reflex transfers by which patterns of the above-mentioned type can be transferred in one step to textiles or the like by heat application.

In the process of the invention, first a plastisol transfer is produced by printing a desired pattern in mirror-inverted fashion with plastisol ink on a suitable substrate, preferably silicone or wax treated paper, by a suitable printing method, preferably silk-screen printing, and the method is characterized in that said plastisol transfer is coated with an elastomer granulate of a type compatible with the plastisol ink and with the surface layer of a reflex transfer film, and the granulate is fused into the plastisol print by heating, following which a reflex transfer film cut to the contour of the pattern is positioned with the reflecting side inwards against the elastomer treated plastisol print and adhered to it by brief heating under a quite

slight pressure to form a combined plastisol reflex transfer, which is finally transferred to the textile or the like by conventional heat application, or the cut reflex transfer film is first applied to the textile or the like with the reflecting side outwards by normal heat activation, and the elastomer treated plastisol print is subsequently applied on top of the reflex film by conventional heat application.

The combined plastisol reflex transfer of the invention is characterized in that it consists of a substrate, preferably silicone or wax treated paper, which carries a desired pattern printed in mirror-inverted fashion with plastisol ink and an overlying reflex transfer film cut to the contour of the pattern with the reflecting side inwards against the plastisol print and anchored to it by means of a fused elastomer of a type which is compatible with both the plastisol ink and the surface layer of the reflex transfer film.

For the purpose of the invention, there may advantageously be used plastisol inks which predominantly consist of modified PVC dissolved in high- boiling organic solvents, e.g. the one marketed by Farbenfabrik Prδll GmbH & Co. under the name of "Tex- Ink", or the one marketed by Sericol Group Ltd. under the name of "Texopaque OP", or the one marketed by Union Ink on a licence from John T. Keep & Sons Ltd. under the name of "ϋltrasoft Plus 1000".

Expediently, an elastomeric granulate on the basis of polyacrylic amide is used, optionally with incorporated PVC, e.g. the one marketed by CHT Group of Companies under the name of "Tubitrans Elastomelt", or the one marketed by KISSEL + WOLF GmbH under the name of "Kiwomelt".

As a reflex film for the purpose of the invention may be used both films with micro glass beads and films with micro prisms and of both open, semi-open, closed and capsule types, preferably as reflex transfer films with a heat activated adhesive. Highly elastic reflex transfer films of the glass bead type are particularly useful in connection with flexible textiles. Special examples of useful reflex transfer films are the one marketed by Unitika Sparklite Ltd. under the designation of "MR 3501", those marketed by 3M Corp. under the name of "Scotchlite" 8700 Series, and those marketed by Reflexite Corp. under the designations of "AP 1000 HA" and "IRE HA".

Fusing of the elastomeric granulate into the plastisol print by the method of the invention is usually performed in a heating furnace, e.g. and infrared heat¬ ing furnace in which the granulate is heated to 130 to 200°C, preferably about 180°C.

In one embodiment of the method of the invention the reflex transfer film is adhered to the elastomer-treated plastisol print by heating the superimposed layers to 130 to 180°C, preferably about 160°C, under a very slight pressure which just serves to keep the layers together, for 2 to 10 seconds, preferably about 5 seconds. This heating may e.g. be performed in an ordinary heat press to transfer plastisol transfers to textiles, but just under the pressure of the own weight of the heat plate.

The reflex transfer film may be handled particularly conveniently during its cutting to the contour of the pattern and application to the elastomer treated plastisol transfer in that the reflex transfer film, in contrast to what is usually the case, is provided with a carrier of silicone or wax treated paper on the adhesive

side. The advantage is that the resulting plastisol reflex transfer is provided with a protective coating of silicone or wax treated paper which is peeled off prior to heat application to textile or the like.

The invention will be illustrated more fully by the _. following example.

EXAMPLE 1

A desired pattern is printed in a silk screen printing machine in mirror-inverted fashion on silicone paper with plastisol ink of the brand "Tex-Ink", marketed by Farbenfabrik Prδll GmbH & Co. Printing is effected for a number of times corresponding to the number of inks in the pattern.

Before the ink layer dries, the paper is run through a vessel with elastomer granulate of the brand "Tubitrans Elastomelt" with a 95S fineness, marketed by CHT Group of Companies, so that the ink will be coated with granulate. Then the paper is shaken so that excess powder disappears.

The plastisol transfer with applied granulate is then run through an infrared heating furnace on a conveyor belt with a distance to the radiating elements of about

10 cm and a temperature of these of 340 to 350°C, which should give a temperature in the granulate of about

180°C. Time of residence about 20 seconds.

Then a reflex transfer film of the brand "Unitika MR 3501" marketed by Unitika Sparklite Ltd., is cut in a suitable format corresponding to or slightly smaller than the contour of the plastisol pattern. The elastomer treated plastisol transfer is inserted in a heat press

with the ink side upwards, and the cut reflex transfer film is applied with the reflex side downwards against the plastisol print. High lustre wax paper is placed on top of the assembly, and then the heat plate with a temperature of about 160°C is applied to the paper with a pressure which just corresponds to its own weight for about 5 seconds. Then the transfer with the high lustre paper is removed and is allowed to cool quite briefly, following which the high lustre paper is removed.

This provides a plastisol reflex transfer according to the invention.

When this is transferred to textile in the heat press at a temperature of 160 to 180°C and a pressure of about 500 kPa for 15 to 20 seconds, the result is a textile with a firmly adhered and durable pattern comprising highly light-reflecting areas defined by inked areas.

EXAMPLE 2

The procedure of Example 1 is repeated, except that a reflex transfer film of the brand "Scotchlite 8710" marketed by 3M Corp. is substituted for the "Unitika MR 3501" film.

When the plastisol reflex transfer is transferred to textile as described in Example 1, the result is a textile with a firmly adhered and durable pattern having an even better resistance to dry cleaning.