GB2255528A

GB2255528A - Transfer sheet and transfer printing using the same.

Info

Publication number: GB2255528A
Application number: GB9109998A
Authority: GB
Inventors: Chen-Chin Huang; Ten-Tsann Wang
Original assignee: HUANG CHEN CHIN; WANG TEN TSANN
Current assignee: HUANG CHEN CHIN; WANG TEN TSANN
Priority date: 1991-05-09
Filing date: 1991-05-09
Publication date: 1992-11-11
Also published as: GB9109998D0

Abstract

A transfer sheet comprises a backing sheet (10) which is coated with a layer of release agent (13) followed by a protective polymer layer (11) and a coating of dye (12) constituting a reverse picture or print. The transfer sheet is placed on a receiving object (20) with the dye coating (12) in contact with the object and heat at a temperature of 100 DEG C-200 DEG C and pressure of 1-10 Kg/cm<2> are applied for 3-60 seconds to cause the polymer of the protective layer (11) to melt and flow through the coating dye (12) onto the object (20). The backing sheet (10) and release layer (13) are then removed to leave the dye coating (12) firmly adhered to the object (20) with the dye coating (12) embedded therein. The dye coating (12) is fully protected from detachment or abrasion by the protective layer (11) which is transparent so that the dye coating can be clearly seen therethrough. <IMAGE>

Description

Title: TRANSFER SHEET AND TRANSFER PRINTING USING THE SAME This invention relates generally to a transfer sheet, the process of making the same, and the process of transfer printing using the same. In particular, the present invention relates to a transfer sheet having arranged thereon one or more print dyes and polymers, which can be transferred simultaneously onto an object by applying heat and pressure to the back side of the sheet.

A conventional transfer sheet is as shown in Fig. 1. It generally consists of a sheet of paper or plastics 1, one side thereof is pre-treated with a release agent 2, on top of the treated surface are arranged respectively a reverse picture or print 3 and a coating of bonding agent 4. The manner of transferring the picture or print on the sheet onto an object is as shown.in Fig. 2. The transfer sheet is placed on a receving object 5 so that the bonding agent 4 is in. immediate contact with the receiving object 5. Heat and pressure are then applied to the back side of the transfer sheet 1 so that the bonding agent 4 adheres onto the surface of the receiving object 5. Lastly the transfer sheet 1 is removed from the receiving object 5, and the whole process of transferring the picture or print 3 on the sheet 1 onto the receiving object 5 is completed.

However, with the above-mentioned conventional process of transfer, the picture or print 3 thus transferred will project from the surface of the receiving object 5 in the form of relief without any kind of proper protection (see Fig. 2). The transferred picture or print 3 is therefore vulnerable to ultraviolet rays present in sunlight and will gradually fade; it is also subject to physical friction so that the picture or print 3, together with the bonding agent 4, will be rubbed off degree by degree until the picture or print completely disappears.

The present invention aims to provide an improved transfer sheet by which a picture or print can be transferred durably onto an object. A further aim is to provide a process of making such a transfer sheet. A still further aim is to provide a process of transferring a picture or print onto an object by using such a transfer sheet.

According to the present invention, the transfer sheet comprises a sheet treated with a releasing agent, a coating of dye, and a protective layer constituted of polymers provided therebetween. The protective layer can be formed of at least one of the following polymers: 1. Polyethylene, PE: * CH,-CH2d- 2. Methylene Vinylacetate Copolymer, EVA

3. Modified EVA Resin

4. Ionomer Resin, 10

5. Polyurethane, PUR

6. Polybutylene

According to the present invention, the process of making the transfer sheet comprises a protective layer constituted of -at least one kind of polymers provided between the layer of dye and the sheet.

According to the present invention, the process of transfer printing using a transfer sheet comprises placing the transfer sheet on a receiving object so that the layer of dye is in immediate contact with the receiving object, applying a suitable amount of heat and pressure to the back side of the transfer sheet so that the heated polymers quickly melt and flow through the layer of dye perpendicularly into the receiving object. After congealation, the melted polymers are firmly secured to the receiving body, and at the same time, they can form a protective membrane for the picture or print thus transferred.

The invention will now be further described, by way of example, with reference to the drawings, in which: Fig. 1 is a schematic view of the conventional transfer sheet; Fig. 2 is a schematic view showing the condition wherein the picture or print is transferred onto the receiving object using the conventional transfer sheet; Fig. 3 is a schematic view of the transfer sheet according to the present invention; and Fig. 4 is a schematic view showing the condition wherein the picture or print is transferred onto the receiving object using the transfer sheet according to the present invention.

Reference is now made to Fig. 3. A sheet 10 is first coated with a layer of release agent 13 (such as wax) and then a protective layer formed of at least one of the abovementioned polymers, and on top thereof is arranged a layer of dye 12 constituting a reverse picture or print.

Obviously it is also possible to use a photograph and the like in place of the picture or print to be transferred, and the layer of dye can be-constituted of several kinds of paints or printing ink.

As shown in Fig 4, when the transfer sheet according to the present invention is utilized in transfer printing, it is placed on a receiving object 20 so that the coating of dye 12 is in immediate contact with the receiving object 20.

Then to the back side of the transfer sheet at the area to be transferred, heat of 100" C -200 C and pressure of 110kg/cm2 are applied within the span of 3-60 seconds, so that the polymers of the protective layer are caused to melt and quickly flow through the coating of dye 12 perpendicularly into the receiving object 20. After congealating, the polymers are firmly secured to the receiving object 20, and when the sheet 10 is removed, they can also form a transparent protective membrane for the picture or print thus transferred.

Because the polymers forming the protective layer according to the present invention has a different polarity from that of the dyes or printing ink, they will not melt into each other when heat and pressure are applied. Different polarities can produce a certain degree of exclusion; therefore, when heat and pressure are applied the back side of the transfer sheet according to the present invention, the melted polymers can flow through the minute spaces in the dyes or printing oil and also the tiny spates naturally present in screen printing or screen block printing into the receiving object, and they will not mix with the dyes or printing oil- to cause the picture thus transferred to become blur.

The sheet is first treated with a release agent 13, such as a thin layer of wax, which is provided between the ' sheet 10 and the protective layer Qf polymers 11. When the sheet 10 is subjected to heat and pressure, the wax will immediately melt so that the sheet 10 can be quickly separated from the layer of polymers 11.

From the above description, it can be understood that the transfer sheet according to the present invention is characterized in that when it is used in transfer printing, the polymers can firmly secured to the receiving object and can form a transparent protective layer on the picture or print transferred to protect it from ultraviolet rays and possible friction and to insulate it from the atmosphere to prevent oxidation, hence increasing the durability of the picture or print transferred onto the receiving object.

The invention is not restricted to the above-described embodiment but variations and modifications may be made without departing from the scope of the invention.

Claims

1. A transfer sheet comprising a sheet, a protective layer arranged thereon, a layer of release agent provided therebetween, and a coating of dye provided on said protective layer.

2. A process of making a transfer sheet comprising treating a sheet with a release agent; arranging a protective layer constituted of at least one kind of polymers on top thereof, and providing a layer of dye constituting a picture provided on top of said protective layer.

3. A process of transfer printing comprising placing said transfer sheet as claimed in claim 2 on a receiving body so that said coating of dye constituting said picture is in immediate contact with a receiving object, and applying heat of 1000 C -200'C and pressure of l-l0kg/cm2 to the back side of said transfer sheet at the transfer area within the span of 3-60 seconds, so that said polymers of said protective layer are caused to melt and quickly flow through said coating of dye constituting said picture perpendicularly into said receiving object, transferring said picture onto said receiving object and forming a transparent protective layer on said picture thus transferred onto said receiving object when said sheet is removed.

4. A transfer sheet substantially as described herein with reference to Figs. 3 and 4 of the drawings.

5. A process of transfer printing substantially as described herein with reference to Figs. 3 and 4 of the drawings.