EP0513757B1

EP0513757B1 - Thermal transfer printing method and print media

Info

Publication number: EP0513757B1
Application number: EP19920108070
Authority: EP
Inventors: Nobuyoshi Taguchi; Akihiro Imai; Soichiro Mima; Yasuo Fukui; Hiroyuki Matsuo
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1991-05-13
Filing date: 1992-05-13
Publication date: 1998-09-02
Anticipated expiration: 2012-05-13
Also published as: EP0513757A1; DE69226806T2; DE69226806D1

Description

The present invention relates to a thermal transfer printing method according to the preamble of claim 1. The method is capable of printing high quality images on a plain paper sheet.

In the field of thermal transfer printing, there has been known a dye thermal transfer printing method which is the only printing technique superior in compactness of size, facilitated maintenance and instantaneous operation of an apparatus employed therefor and in being capable of providing an image of high quality equal to that in the color photography. In the dye thermal transfer printing method as referred to above, the arrangement is such that a transfer member having a coloring material layer containing a sublimining dye provided on a thin film base and an image-receptor or image receiver provided with a dyeing layer on a thick film such as a synthetic paper or the like are overlapped with each other, and by transferring the subliming dye into the dyeing layer through employment of a thermal recording head, a color mixed image of dye molecules is recorded or printed.

The printing is generally effected by driving the image-receptor and by causing a transfer member to follow the movement through frictional force between the image-receptor and the transfer member.

On the other hand, in order to affix the printed image onto various places, there has also been conventionally proposed a practice which employs tack sheets. In this practice, the image-receptor has a double-sheet structure, and an adhesive material is applied onto a reverse surface of a base material formed with an upper dyeing layer so as to be fixed on a support member provided with a lower parting layer, whereby after printing, the upper layer is separated or peeled off for being fixed on a post-card, etc.

Meanwhile, printing of characters or letters has been effected on a plain paper sheet smoothed on its surface through employment of a molten ink transfer member.

As described above, the printed image by the dye thermal transfer printing method is formed on the specially prepared paper sheet. Therefore, running costs tend to be high, and printing speed is relatively low, thus preventing said printing technique from spreading widely for general applications.

Moreover, in the recent times of multi-media, information includes images mixed with characters, and despite a strong demand for printing such information on a plain paper in the similar manner as in a copying apparatus, it has been impossible to obtain an image of high quality on a plain paper sheet by conventional dye thermal transfer printing methods.

Document EP-0 395 014-A1 comprises a thermal transfer material including a support and a heat-transferable ink layer disposed thereon, wherein the heat-transferable ink layer has a storage elasticity modulus E' satisfying the relationship 1 x 10⁷ ≤ E' ≤ 1 x 10⁸ N/m² at 30 °C. The temperature providing a thermal differential value of the dynamic energy loss angle (tanδ) satisfying the relationship d(tanδ)/dT = 1 x 10-2 is in the range of 40 to 60 °C.

It is the object of the present invention to provide a thermal transfer printing method which is capable of providing a pictorial image at high quality which has up to the present been obtained only on expensive special paper, irrespective of the kind of image-receptors and even when the image is mixed with characters.

Another object of the present invention is to provide a thermal transfer printing method which may be readily adopted in actual applications in an efficient manner and at low costs.

These objects are attained by a method as defined in claim 1. Preferred and suitable embodiments of said method are defined in the subclaims.

In the present invention, the dyeing layer may be heat transferred partially or totally onto the base material by a thermal recording means such as a thermal head or a hot roller or the like. Also, the dyeing layer may be formed partially or totally on the base material by means of printing or the like. In the present specification therefore, "recording member" means any base material provided with the dyeing layer that has to be thermally transferred along with the colouring material. The colouring material (such as a dye and/or a molten ink) of the colouring layer on the transfer member is thermally transferred onto the dyeing layer of the recording member. In case that the colouring layer comprises both the dye layer and the molten ink layer, it is preferred that the molten ink layer is transferred first, with the dye layer being transferred thereafter. In case that the recording member is used as the final image-receptor, the base material is mostly a pulp paper. In case that the recording member is used as an intermediate member recording after recording the colouring material, only the recorded dyeing layer may be thermally transferred onto the final image-receptor such as pulp paper or the like by means of thermal transferring or thermal setting.

By the method according to the present invention as described so far, pictorical images at high quality which can be obtained only on the expensive special paper may be obtained without selection of the image-receptors, even when the images are mixed with characters. Thus, printing less dependent on the quality of paper can be effected onto the bond paper, plain paper, etc. Particularly, even with respect to the high speed printing, or high temperature recording, the dyeing layer may be selectively formed or transferred on to the recording member and thus stable colour recording may be effected, and the recorded dyeing layer can be thermally transferred stably onto any image-receptor, without any feeling of disorder as in a coating.

The dyeing layer utilized for the present invention is comprised of plastics resin which firstly has a glass transition point of 100 °C or less for transfering a colouring material from the colouring layer to the dyeing layer with ease, secondly has a contacting angle cosine of 0.6 or less measured at 45 x 10^-3 N/m, and thirdly is different from the plastics resin which is used for the colouring layer on the transfer member to improve the peeling properties.

In a preffered embodiment, the dyeing layer contains at least one selected from the group comprising polyvinylbutyral resin and polystyrene resin. More preferably, a low molecular resin may be mixed with the main resin of the dyeing layer to provide softness and low shearing power thereto. The same effect can be obtained by mixing fine particles therewith. Futher, providing a thermal deformation absorbing layer on the second base material of the recording member renders the recording more stable, and especially in the case of the base material of a thin high molecular film, a thermal deformation on recording can be absorbed, which provides a large effect to registration on colour overlapping recording. Also, by providing the roughness to the surface of the base material, the dyeing layer is easy to be transferred onto the base material.

The above and other objects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiment thereof with reference to the accompanying drawings, in which;

Fig. 1 is a schematic side elevational view of an arrangement for explaining a thermal transfer printing method and printing media employed therefor according to one preferred embodiment of the present invention, in which fragmentary cross sections on a large scale are shown for respective essential portions surrounded by dotted circles,

Fig. 2 is a view similar to Fig. 1, which particularly relates to a second embodiment of the present invention,

Fig. 3 is a view similar to Fig. 1, which particularly relates to a third embodiment of the present invention.

Fig.4 is a Zisman plot of estimated cosine of contact angle aganst the resin surface.

Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.

Referring now to the drawings, a thermal transfer printing method and print media employed therefor according to the present invention will be described hereinafter.

It should be noted here that, in Figs. 1,2 and 3 showing arrangements for describing thermal transfer printing method according to the present invention, constructions of essential portions surrounded by dotted circles are given in fragmentary cross sections on a large scale led out therefrom by dotted arrows in each of the figures for quick reference.

Fig. 1 shows an arrangement for explaining the thermal transfer printing method according to one preferred embodiment of the present invention. There is provided a recording member 2 which comprises a dyeing layer 42 formed on a first base material 21 and which is held between a second base material 41 formed on a drum-like configuration metal 4'' and between a thermal head 3-1, whereby thermal transfer and recording of the dyeing layer 42 is effected onto the surface of the second base material 41. In the specification, any base material that is provided with the dyeing layer 42 at the surface and is in the state just before recorded by a colouring material is reffered to as "recording member ". The base material of the recording member may be formed into a sheet-like shape such as a polyethylene terephthalate film (PET) or the like. The dyeing layer 42 is subjected to selective transfer only of a portion where the dye is printed later or to the transfer for a predetermined whole area. Reference numeral 2' in Fig. 1 represents the state after the dyeing layer 42 has been transferred. As the thermal head 3-1, a thermal roller may be used. Subsequently, through employment of a molten ink transfer member 1 having a colouring layer containing a molten ink 12 as a colouring maaterial and having the thermal head 3-2, the molten ink is subjected to thermal diffusion transfer into the dyeing layer 42 for printing letter or characters. Reference numeral 11 denotes a base material of the molten ink transfer member, while 13 is a lubricant heat-resistant layer. Through employment of a transfer member 8 having a colouring layer 82 containing a subliming dye and further having a thermal head 3-3, the colouring layer 82 is subjected to thermal transfer and recording onto the recorded dyeing layer 42 for printing full colour images. Reference numeral 81 denotes a base material of the transfer member and 83 is a lubiricant heat-resistant layer Finally, the colour image recorded in or on the dyeing layer 42 of the intermediate recording member 4 is thermally transferred onto the image-receptor 5 together with the dyeing layer 42 through employment of a heat roller 7 to be setted thermally. Reference numeral 6 shows the state where the recorded dyeing layer 42 is provided on the image-receptor 5.

Fig. 3 shows a further arrangement for explaining the thermal transfer printing method according to another embodiment of the present invention.

In the embodiment, there may be used a recording member 4' which comprises the dyeing layer 42 provided on a thin base material 41 of PET or the like by a printing process or the like. By employment of the recording member 4' (which is preliminarily provided with the dyeing layer 42 directed along the drum 4''), the transfer member 1 (which is provided with a molten ink layer 12) and by the thermal head 3-2, the molten ink of the ink layer 12 on the ink transfer member 1 is thermally diffused and transferred into the dyeing layer 42 or on the base material (not provided with any dyeing layer) of the recording member. In case that a printing apparatus is not required to print characters, the portion by the combination of the molten ink transfer member 8 and the thermal head 3-2 is not required. Subsequently, by using the dye transfer member 8 and the thermal head 3-3, the subliming dye layer 82 on the dye transfer member 8 is thermally transferred and recorded on the dyeing layer portion on the recording portion to print full colouring images. Finally, by thermally transferring the item recorded on the recording member 4' (the image recorded in or on the dyeing layers 42) onto the image-receptor 5 together with the dyeing layer through employment of a heat roller 7, a high quality image by the dye and molten thermal transfer printing can be obtained without depending on the quality of the material for the image-receptor. Reference numeral 6 shows the state where the recorded dyeing layer 42 is provided on the image-receptor 5.

In the case of the dyeing layer with small amount of the lubricant material or without any lubricant material, the molten ink is transferred sufficiently thereon. Further, it is preferred to record the molten ink before recording of dye layer, because very samll amount of the lubricant material may be transferred into the dyeing layer.

Since the specific constructions of the ink transfer member 1, the dyeing layer transfer member 2, and the molten ink transfer member 8 are similar to those in the embodiments of Figs. 1 , detailed description thereof is abbreviated for brevity, with like parts being designated by like reference numerals.

Fig. 2 shows another arrangement for explaining the thermal transfer printing method according to a second embodiment of the present invention.

In the embodiment of Fig. 2, the dyeing layer recording member 2, the molten ink transfer member 1 and the colouring layer transfer member 8 of the Fig. 1 embodiment are formed into one unit as shown in the transfer member 100. More specifically, the thermal transfer of the dyeing layer, the subliming dye and the molten ink is effected by the same thermal head 3-2. In the transfer member 100, the molten ink layer 12-1 and the colouring layer 82 are formed in one colour or in a plurality of colours by the face order subsequent to the dyeing layer portions 42. Since the process after the subliming dye has been recorded on the dyeing layer is the same as in the embodiment of Fig. 1, a detailed description thereof is abbreviated for brevity, with like parts being designated by like reference numerals.

In the case of using the final image-receptor base material such as pulp paper as the recording member base material in Fig.1 and 2, there is not required the thermal transfer and thermal setting process indicated by numeral 7.

In the embodiment of Fig.3, the same process as that of Fig.1 and 2 can be carried out the formation process and arrangement of the recording member different from those of Fig.1 and 2.

In the foregoing embodiment as shown in Fig.1, the second base material 41 of the recording member 4 is constructed by winding a head-resistant rubber such as a heat-resistant high polymer film, silicone rubber and the like on the surface of the metal drum 4'' or the like. For such a heat resistant film, there are also exemplified films composed of resins capable of forming film such as aromatic polyimide (aramide), polyimide, polycarbonate, PET(polyethylene terephthalate), cellophane, etc. In case that the second base material 41 comprises a heat-resistant film, it is advantageous for registration on overlapping recording that there is provided a heat deformation absorbing layer on said second base material 41. This layer may be comprised of a resin layer with rubber elasticity or a resin layer wity high void content. As the example of the resin layer with rubber elasticity, SBR (styrenebutadiene rubber) or the one represented by latex thereof are useful. Also, an acrylonitrilebutadiene or the like is useful for the purpose. Additives such as fine particles or the like may be added to the layers.

In the case of using the base material for the recording member comprising a high polymer or high molecular film, provision of a rough surface make the dyeing layer easy to be transferred. The rough surface may be formed by addition of particles thereto or by the rubbing paper of roughness No.1000.

The dyeing layer recording member 2 shown in Fig.1 includes a base material 21 and a dyeing layer 42 on said base material 21. To selectively transfer the dyeing layer 42 from the base material 21 to the base material 41 on the recording member 4 by means of thermal means and to improve the sensitivity on colour recording, and also to transfer the recorded dyeing layer finally to the image-receptor, it is necessary to maintain the adhesive property of the dyeing layer against the

base materials

21 or 41 to be in a state of semi-stability. Therefore, it is desired that the surface energy of at least a main resin used for the dyeing layer is smaller, that is, smaller than that where cosine value of the contact angle of the resin without additives indicates 0.6. Fig.4 shows a plot of estimated surface energy of four kinds of resins and PET film. The axis of abscissae indicates a surface tension of test resin and the axis of ordinates indicates a cosine of the contact angles. The cosine of the contact angle in the present invention is defined by the value measured at 45 N/m (45 dyn/cm) or more. Fig.4 shows that the cosine values of polyvinylbutyral(PVB) and polystylene(PSt) resins are below 0.6 while those of sarturated polyester(PEs) and AS resin are above 0.6 as similar to that of PET film. Therefore, the PVB and PSt resin are useful for the present invention.

Further, since the dyeing layer is required to be transferred onto the image-receptor at the final process after the recording, the glass transition temperature Tg of the dyeing resin should preferably be as low as possible so long as no problem is brought about in the recording or printing. For preparing composite resins of PVB and PSt, vinylchroride-vinylacetate copolymer resin, saturated polyester resin, polyacetal resin such as polyvinylbutyral, acrylic resin, urethane resin, polyamide resin and the like may be used. The dyeing layer has a lower grass-transition temperature Tg of 100 °C or less.

Furthermore, it is important that the resin used for the dyeing layer different from the main resin used for the colouring layer. THereby, the melting adhesion between the colouring layer and the dyeing layer can be prevented on recording.

For lowering the glass transition temperature Tg as the system of the dyeing layer and controlling the surface frictional characteristics thereof, it is effective to mixed the above high molecular resin with a low molecular resin. As the low molecular resin, a general hot melt resin may be used, especially a low molecular polystyrene resin is preferred. The other examples are a low molecular polyethylene, a petroleum resin, a rosin resin, a terpene resin, a cumarone resin, an alicyclic saturated hydrocarbon resin, a ester gum, and high molecular waxes for the purpose.

Futher, it is effective in many cases to add the lubricating material or releasing material to be described later. Particularly, acrylsilicone resin (silicone) having siloxane methacrylate at the terminal or side chain is effective. The acrylsilicone resin may be modified to have a silane coupling agent comprising an alkoxysilyl group or the like at the terminal chain and acted with trace moisture in the atmosphere to give a resin provided with a siloxane bonding (siloxane-contained, moisture-hardening type resin), which is useful. An acryl (silicone) resin having fluorine methacrylate at the terminal or side chain is also effective. If necessary, these resins may be used with a reaction accelerator.

For the releasing agent or material to be added to resin, there are available various silicone group lubricants, fluorine group surface-active agent, waxes such as paraffine, and polyethylene, etc., higher fatty group alcohol, higher fatty acid amide and ester, etc. As the liquid state lubricants, dimethyl polysiloxane, methylphenylpolysiloxane, fluorosilicone oil, various denatured silicone oil, reactants of more than two kinds of reactive silicone oils (e.g. reactants of the epoxy modified and the carboxyl or amino modified, etc.) are employed. Similarly, reaction type of resin and lubricant may be employed, and for example, water soluble polysiloxane graft acrylic resin prepared by subjecting polysiloxane to graft polymerization with acrylic resin, acrylic silicons (silicone) resin added with siloxane methacrylate at the terminal or chain side or acrylurethane silicone (silicon) resin, etc. are effective.

Furthermore, fine particles may be added to the dyeing layer. Especially, inorganic fine particles such as silica, titanium white, barium sulfate, zinc oxide, etc. which protrude from the surface of the dyeing layer are very effective for the selective transfer of the dyeing layer and the transfer of the recorded dyeing layer to the image-receptor.

The colouring layer transfer member 8 includes a base material 81, a heat-resistant lubricity layer 83 formed on the reverse face of the base material 81, and colouring layer 82 provided on the upper face thereof. The base material 81 is made of a high polymer film of 2 to 20 microns in thickness. For such a film, the PET (polyethylene terephthalate) film is generally employed, but films composed of resins capable of forming films such as aromatic polyimide (aramide), polyimide, polycarbonate, polyphenylene sulfide, polyether ketone, triacetyl cellulose, and cellophane, etc. are also useful for the purpose. Similarly, resistant films formed by mixing electrically conductive particles such as carbon, etc. into such resins may also be employed. The colouring layer 82 is composed of at least a subliming dye and a bonding agent. For the subliming dye, the dispersing dye, oil soluble dye, basic dye, color former, etc. are used. Particularly, dispersing dyes of indoaniline group, guinophthalone group, dicyano imidazole group, dicyano methine group, tricyanovinyl group, etc. are useful. For the bonding agent, polyester, polyvinyl butyral, acrylstyrene resin, etc. are employed. If necessary, a lubricant agent and fine particles may be used. The heat resistant lubricity layer 13 is provided to impart a lubricating characteristic between the thermal head 3 and the base material 81 and is formed into the film by the ultra-violet curing resin, liquid state lubricant, inorganic fine particles or the like.

Meanwhile, the image-receptor or image receiving material 5 may be of the pulp group paper such as the bond paper, plain paper, etc. or it may be of the synthetic paper such as a semi-translucent PET film YUPO, etc. or of a base material prepared by bonding pulp paper with a film.

For the recording heads 3-1,3-2 and 3-3, normal thermal heads, energizing heads, laser heads, etc. are employed. The recording conditions when the line type thermal head is employed are as follows. Line recording period T: 33ms to 4ms, impression pulse width: 16ms to 2ms, and recording energy E: 8 to 4 J/cm². The thermal transfer of the recorded dyeing layer onto the image-receptor 5 is effected under such conditions as temperature: about 180°C, speed: 10mm/sec., and pressure 4kg/1cm when the heat roll 7 is employed.

Hereinbelow, some specific examples are given for explaining the present invention, without any intention of limiting the scope thereof.

Manufacture of the subliming colouring layer transfer member 8

On a PET film anchor layer of 4 microns provided with a lubricating heat resistant layer of 2 microns on a reverse surface, and painted with an anchor layer of 0.3 micron on the front surface, a dye layer was formed with ink as described below by a gravure coater so as to be 1 micron in a solid state thickness.

(Ink)
Indoaniline group disperse dye	2.5 weight parts
Acrylstyrene resin
	4 weight parts
Amide denatured silicone oil	0.02 weight part
Toluene
	20 weight parts
2-butanone	20 weight parts

Manufacture of the molten ink transfer member 1

On a PET film of 6 micron having a heat-resistant lubricity layer of 1 micron formed at the reverse face, black molten ink 82 having the compositions as follows was applied to form a film having a thickness of 2 microns in the dried state.

Wax(NPS-6115, name used in trade and manufacture by Nippon Seiro Co., Ltd., Japan): 3 weight parts

Heat melting resin (YS resin PX-100, name used in trade and manufacture by Yasuhara Yushi Kogyo Co., Ltd., Japan): 1 weight part

Carbon black: 1 weight part

Toluene · IPA mixed solvent: 10 weight parts

Manufacture of the dyeing layer transfer member 2

A base material is the same as that of the dye layer transfermember. On the base material, a dyeing layer as follows was formed.

A paint prepared by mixing 10 weight parts of polyvinylbutyral resin (BL-S, name used in trade and manufactured by Sekisui Chemical Co., Ltd., Japan) 2 weight parts of a low molecular polystyrene (Piccolastic A75 from Hercules Inc.), 1 weight of titanium oxide and 50 weight parts of toluene, form a film having a thickness of 3 micron.

Manufacture of the base material for the recording member 4

A structure in which a PET film of 50 micron thick provided with SBR(L×415A, manufactured by Nihon Zeon Co., Ltd., Japan) of 10 micron thick was disposed on a metallic drum by applying pay-off and take-up was used as the base material for the recording member.

Through employment of mechanisms for driving the colouring layer transfer member 8, dyeing layer transfer member 2, and molten ink transfer member 1 and recording intermediate member 4 for recording, and a heat roller mechanism for continuously transfer the dyeing layer onto the image-receptor, printing was effected under the following conditions, and thus, final images were obtained on bond paper.

Recording head: line type thermal head

Line recording speed: 8ms

Recording pulse width: 0-4ms

Maximum dye recording energy: 6.5J/cm²

Maximum molten ink transfer energy: 2J/cm²

Dyeing layer transfer energy: 3J/cm²

Heat roller: temperature 180°C, feeding speed 10mm/sec. pressure 10kg.

The images obtained on the bond paper in the manner as described above were a high quality pictorial image with maximum reflection density of more than 1.8 and black letters with such density of more than 1.5.

Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as included therein.

Claims

A thermal transfer printing method which employs

a recording member (4') having a dyeing layer (42) formed partially or totally on a base material (41) by means of a printing process or heat transfer process,

a transfer member (8) having a colouring layer (82), and

an image-receptor (5),
whereby a colouring material of the colouring layer (82) is heat-transferred onto the dyeing layer (42) and then the recorded dyeing layer (42) is transferred to the image-receptor (5),
characterized in that

the dyeing layer (42) is comprised of a plastics resin having

(a) a glass transition point of 100 °C or less with ease for transferring a colouring material from the colouring layer (82) to the dyeing layer (42),

(b) a contacting angle cosine of 0.6 or less measured at 45 x 10^-3 N/m (dyn/cm), and

(c) is different from the plastics resin which is used for the colouring layer (82) on the transfer member (8) to improve the peeling properties.
The method of claim 1, characterized in that the dyeing layer (42) is provided on a first base material (21) to be heat-transferred partially or totally onto said base material (41) as a second base material and the colouring material of the colouring layer (82) is heat-transferred onto the dyeing layer (42).
The method of claim 2, characterized by employing a recording member (2) having a dyeing layer (42) formed partially or totally on the first base material (21) by a printing process, at least a second transfer member (8) having a colouring layer (82), wherein the dyeing layer (42) on the first base material (21) is heat-transferred partially or totally onto the second base material (41) and then the colouring material of the colouring layer (82) is heat-transferred onto the dyeing layer (42) on the second base material (41) and thereafter the recorded image on or within the dyeing layer is transferred to the image-receptor (5).
The method of anyone of claims 1 to 3, characterized in that the dyeing layer (42) is formed through a releasing layer partially or totally coated on the first base plate.
The method of anyone of claims 1 to 3, characterized in that the second base material (41) comprises a polymer film provided with an absorbing layer on the surface thereof exhibiting thermal deformation and rubber elasticity.
The method of anyone of claims 1 to 3, characterized in that the second base material (41) comprises a polymer film provided with a rough surface.
The method of anyone of claims 1 to 6, characterized in that the dyeing layer (42) is comprised only of a polymeric resin and the colouring layer (82) is provided with a lubricant material.
The method of anyone of claims 1 to 6, characterized in that the dyeing layer (42) comprises at least a high molecular resin and a low molecular resin.
The method of anyone of claims 1 to 6, characterized in that the dyeing layer (42) comprises at least a high molecular resin, a low molecular resin, and fine particles.
The method of claims 8 or 9, characterized in that the dyeing layer (42) contains a lubricant material.
The method of anyone of claims 1 to 10, characterized in that the transfer member (8) is a colouring layer (82) comprising a dyeing layer (42) and a melting ink layer (12) provided on the same layer or on separate layers.
The method of claim 11, characterized in that the colouring layer (82) of the transfer member (8) is recorded after the ink layer (12) of the transfer member (8) is recorded.
The method of anyone of claims 1 to 12, characterized in that the dyeing layer (42) contains polyvinylbutyryl resin and/or polystyrene resin.
The method of anyone of claims 1 to 12, characterized in that the dyeing layer (42) contains polyvinylbutyryl resin and a low molecular polystyrene resin.
The method of anyone of claims 1 to 12, characterized in that the dyeing layer (42) contains polyvinylbutyryl resin, a low molecular polystyrene resin and a polyester resin.
The method of anyone of claims 1 to 12, characterized in that the dyeing layer (42) contains a polyester resin, and a low or a high molecular polystyrene resin.
The method of anyone of claims 11 to 12, characterized in that the colouring layer (82) contains at least a dye, a main bonding resin, and a low molecular polystyrene resin.
The method of claim 17, characterized in that the colouring layer (82) additionally contains a lubricant material.
The method of anyone of claims 1 to 12, characterized in that the colouring layer (82) contains at least a dye, acrylonitrilestyrene or polyester resin, and a lubricant material.
The method of anyone of claims 1 to 12, characterized in that the lubricant material in the colouring layer (82) or the dye layer is an acryl resin containing siloxane metacrylate or fruorine metacrylate at the end or side chain.
The method of anyone of claims 1 to 12, characterized in that the colouring layer (82) and the dyeing layer (42) are provided on the same base material (11).