KR100212977B1 - Dye doner layer for heat transfer printing ribbon - Google Patents

Abstract

The present invention relates to a thermal transfer ink layer composition, and more particularly, to a polyvinyl butyral, a polyvinyl acetoacetal, a cellulose acetate butylate or a mixture thereof in a thermal transfer ink layer composition of an ink ribbon for sublimation thermal transfer recording. The present invention relates to a thermal transfer ink layer composition containing a binder mixture mixed at a predetermined ratio to improve adhesion to a base film, to improve gradation during printing, and to obtain a high quality image.

Description

Thermal Transfer Ink Layer Composition

The present invention relates to a thermal transfer ink layer composition, and more particularly, to a polyvinyl butyral, a polyvinyl acetoacetal, a cellulose acetate butylate or a mixture thereof in a thermal transfer ink layer composition of an ink ribbon for sublimation thermal transfer recording. The present invention relates to a thermal transfer ink layer composition containing a binder mixture mixed at a predetermined ratio to improve adhesion to a base film, to improve gradation during printing, and to obtain a high quality image.

As a method of recording a color image, an electrophotographic method, an inkjet method, a thermal transfer method and the like are applied. Among them, the thermal transfer recording method is applied to a wide range of fields because there is no noise during printing and the maintenance of the device is easy, and it is classified into a melt type and a sublimation type according to the properties of the transfer ink layer. The melting method is a method in which a transfer ink layer is heated and melted by a thermal element, and then transferred to the receiving layer and solidified. In the transfer process, not only the colorant but also the binder component is transferred to the receiving layer. . In the sublimation type method, the transfer ink layer is composed of a thermal sublimable dye and a binder, and only the dye is transferred to the receiving layer in proportion to the thermal energy applied by the thermal element, thereby forming an image, also called a dye diffusion type. This sublimation type control the amount of dye transferred in proportion to the applied thermal energy, so it is easy to express continuous concentration gradation on the transfer image, so it is not only widely used in office automation equipment such as facsimile machine and copier, but also in CAD, CAM, etc. It is widely used in the field of graphic design, or in the field of printing a color image which is electrically expressed from a color video camera through a color printer.

The recording principle of the sublimation thermal transfer recording method is as follows.

The sublimation thermal transfer recording method decomposes a color image reproduced by an electric signal by using a color filter, and separates it into three images of red (R), green (G), and blue (B). Is transmitted to the thermal element of the printer in the form of an electrical signal.

In response to the transmitted electrical signal, the thermal element applies thermal energy to the opposite side of the surface of the transfer ink layer of the thermal transfer ink ribbon to which the dye, yellow, magenta, cyan or black applied to the ink ribbon is applied. It is transferred to a receiving paper to obtain an image by a combination of four dyes.

In the thermal transfer ink ribbon, a transfer ink layer is coated on one side of the base film, and an adhesive layer is formed between the ink layer and the base film to improve adhesion between the ink layer and the base film. The heat-resistant lubricating layer is applied to prevent the substrate film from being pressed to the thermal element by the heat generated by the thermal element during printing. The transfer ink layer is composed of a sublimation thermal transfer dye which is transferred to the receiving layer by heat and a binder for maintaining the dye on a base film. In the manufacture of a sublimation thermal transfer ink ribbon, selection of a binder having appropriate physical properties is important, and the physical properties required for such a binder component are as follows.

(1) In order to obtain high transfer sensitivity, the transfer ink layer should be easy to transfer dye to the receiving layer.

(2) Excellent adhesion to materials used for sublimation thermal transfer ink ribbon.

(3) No fusion with the receiving layer should occur during printing.

(4) Due to the proper affinity with the dye, recrystallization of the dye should not occur.

(5) In order to obtain excellent gradation expression, the transfer sensitivity at low applied energy should be as low as possible.

As a result of research for obtaining a binder satisfying the above requirements, a method of using various kinds of binders in the transfer ink layer of a sublimation thermal transfer ink ribbon has been proposed.

U.S. Patent No. 4,700,207 uses cellulose resins such as cellulose acetate butyrate, ethyl cellulose, cellulose acetate phthalate and the like as binders. The cellulose-based resin lacks an adhesive force with a polyethylene terephthalate film widely used as a base film, so that a phenomenon in which the transfer ink layer falls from the base film during image printing may occur.

In addition, a method of using polyvinyl acetal resins such as polyvinyl butyral [US Pat. No. 4,650,494] and polyvinyl acetoacetal [European patent 0,271,861] is known. When polyvinyl butyral binder is used, high transfer sensitivity can be generally obtained at high applied energy. However, high transfer sensitivity at low applied energy is disadvantageous, resulting in disadvantageous precision gradation and poor adhesion to the base film. And polyvinyl aceto acetal binder has a disadvantage of poor transfer sensitivity.

The present inventors have endeavored to solve the problems shown in the sublimation heat transfer printing method, and as a binder component in the thermal transfer ink layer composition, polyvinyl butyral as an essential component, polyvinyl acetoacetal, cellulose acetate butylate or The present invention was completed by knowing that a mixture of these mixtures was mixed at a constant ratio, thereby ensuring excellent physical properties and gradation expression ability due to their synergistic and complementary actions.

Accordingly, an object of the present invention is to provide a thermal transfer ink layer composition which improves adhesion between a dye and a base film to have excellent physical properties, and improves gradation when printing to enable excellent gradation expression.

In the sublimation type thermal transfer ink layer composition, the ink layer composition contains a binder mixture containing polyvinyl butyral as an essential component and a mixture of polyvinyl acetoacetal, cellulose acetate butyrate or a mixture thereof. The heat transfer ink layer composition is characterized by the above-mentioned.

Referring to the present invention in more detail as follows.

The heat transfer lubricating layer is coated on one side of the base film, and the transfer ink layer including a sublimation type thermal transfer dye is coated on the opposite side thereof. A new thermal transfer ink layer composition containing a binder mixture containing butyral, polyvinyl acetoacetal, cellulose acetate butyrate or a mixture thereof in a proportion to improve the adhesion between the dye and the base film and having excellent gradation It is about.

In the present invention, polyvinyl butyral is an essential ingredient in the transfer ink layer composition, and polyvinyl acetoacetal, cellulose acetate butyrate, or a mixture thereof is mixed and used at a constant ratio.

Although they have been used as a binder component of the transfer ink layer in the past, when each of them is used alone or when a different binder is mixed with each of these components, the adhesion between the base film and the dye decreases or the gray scale expression is poor. It has many of the disadvantages described above. However, when they are used in an appropriate content range, they exhibit excellent physical properties that cannot be expected by single use.

The mixing ratio of the binder mixture is 30 to 250 parts by weight, more preferably 50 to 200 parts by weight of polyvinyl acetoacetal, cellulose acetate butyrate or a mixture thereof based on 100 parts by weight of polyvinyl butyral. use. If the content of polyvinyl acetoacetal, cellulose acetate butylate, or mixtures thereof is too small, there is a problem in precise gradation expression due to high transfer sensitivity at low applied energy, and if the content is too high, adhesion to the base film is degraded or There is a problem that the transfer sensitivity at a high applied energy is lowered.

In addition, it is preferable that the binder mixture prepared by mixing the resins contain about 30 to 70% by weight based on the total solids of the thermal transfer ink layer composition. When the content of the binder is less than 30% by weight, the adhesive strength with the base film is increased. When it falls, when it exceeds 70 weight%, a transfer sensitivity will become low too much.

As described above, the thermal transfer ink layer composition of the present invention contains a binder mixture, a sublimation dye having a thermal transfer property, a suitable solvent, and various additives such as an antioxidant, a UV absorber, and a dye crystallization inhibitor, as necessary. .

Sublimation dyes with thermal transfer properties include red dyes such as Magenta VP, MS Red G, Macrolex Red Violet R, MS Magenta HM-1450, yellow dyes such as Waxoline Yellow GFW, Kayaset Yellow GN, and Foron Brilliant Yellow 6GL. Blue dyes, such as Kayaset Blue 714, Waxoline Blue AP-FW, MS Cyan HM-1238 can be used, these dyes can be used alone or mixed in a suitable ratio according to the desired conditions.

At this time, the thickness of the transfer ink layer to be applied is adjusted to 0.5 to 5.0 ㎛ in the dry state.

Substrate films used in the manufacture of sublimation thermal transfer ink ribbons may be polyester films such as polyethylene terephthalate, polyamides, polyacrylates, polycarbonates, cellulose esters, fluorine resins, polyacetals, or polyimide films. Among these, polyester film is most suitable for economical and mechanical strength. 2-20 micrometers is suitable for the thickness of the base material used at this time. In order to improve adhesion to the thermal transfer ink layer, an adhesive layer is often applied on the base film, corona discharge, or plasma treatment, and a gravure coating method or a bar coating method on the treated film as described above. The dye layer is applied by using.

On the opposite side of the surface to which the transfer ink layer of the base film is applied, the base film is prevented from being deformed when it comes into contact with a heat element that generates heat up to 400 ° C. The heat resistant lubricating layer can be designed. As the material used for this purpose, carboxylate, sulfonate, phosphate, aliphatic amine salt, polyoxyethylene alkyl ester, silicone oil or synthetic oil may be used.

As the receiving layer to which the dye layer applied to the thermal transfer ink ribbon is transferred, any sheet-like material having a property of accommodating the transferred dye is used, and polyester, polycarbonate, vinyl chloride-vinylacetate air is used. Copolymer, polyvinyl chloride, ABS resin, etc. are used. Recently, a card made of PVC is also used as a receiving place to manufacture various ID cards such as bank cards and credit cards. It is also possible to use paper, metal, glass or synthetic resins that do not have dye solubility. At this time, an aqueous layer made of a resin capable of accommodating the dye transferred to at least one side is applied.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Examples 1-7, Comparative Examples 1-3

After applying the adhesive layer composition of Table 1 to the front surface of the Toray Corporation, Japan's Toray Co., Ltd. (Trade name: FC-531), which was not heat-treated, And the transfer ink composition of Table 1 were applied to produce an ink ribbon for sublimation thermal transfer recording according to the present invention.

TABLE 1

Composition Example Comparative example One 2 3 4 5 6 7 One 2 3 Adhesive Layer Composition (Weight) p-chlorophenol 3 3 3 3 3 3 3 3 3 3 toluene 97 97 97 97 97 97 97 97 97 97 Transfer Ink Layer Composition Weight% Sublimation Dye Magenta Dye ⁽¹⁾ 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00 Binder Polyvinylbutyral ⁽²⁾ 2.50 2.50 3.00 1.70 2.00 2.50 3.00 5.00 - - Polyvinylacetoacetal ⁽³⁾ 2.50 - 2.00 3.30 - - 1.00 - 5.00 - Polyvinylacetoacetal ⁽⁴⁾ - - - - - 2.50 - - - - Cellulose Acetate Butylate ⁽⁵⁾ - 2.50 - - 3.00 - 1.00 - - 5.00 solvent toluene 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 N, N-dimethylformamide 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 44.00 (1) Magenta Dye (Mitaido VP, Japan) (2) Polyvinyl Butyral (Japan Red Chemical, BX-1) (3) Polyvinylacetoacetal (Japan Red Chemical, KS-1) ( 4) Polyvinyl acetoacetal (manufactured by Japan Epoxy Chemicals, KS-5) (5) Cellulose acetate butyrate (manufactured by Akros Japan)

Experimental Example

Gray scale evaluation images were printed on the thermal transfer sublimation transfer ink ribbons manufactured in Examples 1 to 7 and Comparative Examples 1 to 3 using Persona Cheetah II, which is a card printer manufactured by Fargo, USA. Used.

At this time, the gray scale image was made by dividing the 256 gray scales of magenta color into 10 by using Adobe Photo Shop software, and the printed gray scale image was measured by the optical density measuring device TR-1224 of Mc.Beth of the United States. It was.

In addition, the adhesive force with the polyethylene terephthalate film used as the base film was evaluated by dividing the area of the transfer ink layer torn by 5 equal parts using Scotch Magic Tape of the United States 3M company and the results are shown in Table 2.

TABLE 2

Experiment Gradation Adhesion Stage 1 10 steps Example One 0.16 1.65 One 2 0.15 1.70 One 3 0.16 1.63 One 4 0.17 1.60 One 5 0.16 1.74 One 6 0.18 1.60 One 7 0.17 1.67 One Comparative example One 0.21 1.52 2 2 0.19 1.50 2 3 0.18 1.55 3 Adhesive force judgment standard; Open area 0% → 1 1 to 25% → 2 26 to 50% → 3 51 to 75% → 4 76 to 100% → 5

In the present invention, polyvinyl butyral, polyvinyl acetoacetal, cellulose acetate butyrate, or a mixture thereof is used as a binder of the thermal transfer ink layer of the sublimation type thermal transfer ink ribbon. Compared with the case where the binder is used alone, it can be seen that the transfer sensitivity at low applied energy is lower and the transfer sensitivity at higher applied energy is higher. In addition, the results of the evaluation of the adhesive strength compared to the peeled area, it can be seen that in the above embodiment, the adhesive force with the base film is more improved than when using each binder alone.

From the above results, the ink layer composition of the present invention, in which polyvinyl butyral, polyvinyl acetoacetal, cellulose acetate butyrate, or a mixture thereof is used as a binder of the thermal transfer ink layer of the sublimation thermal transfer ink ribbon, is described. Adhesion with a film is improved, the gradation of the sublimation type thermal transfer ink ribbon is improved, and a high quality image can be obtained.

Claims (3)

A sublimation thermal transfer ink layer composition, wherein the ink layer composition contains a binder mixture containing polyvinyl butyral as an essential component and a mixture of polyvinyl acetoacetal, cellulose acetate butyrate, or a mixture thereof. A thermal transfer ink layer composition. 2. The thermal transfer ink layer composition according to claim 1, wherein the binder mixture is a mixture of 100 parts by weight of polyvinyl butyral, polyvinyl acetoacetal, cellulose acetate butyrate or 30 to 250 parts by weight thereof. . The thermal transfer ink layer composition according to claim 1, wherein the binder mixture is contained in an amount of 30 to 70% by weight based on the total solids of the transfer ink layer composition.