JP3056419B2 - Thermal transfer recording medium and thermal transfer recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium for forming an image by transferring a thermal transfer ink layer on a support to a medium to be transferred by a heat source such as a thermal head printer, and to a thermal transfer recording method therefor. Yes, it can be transferred well on a transfer medium such as a plastic film, and the transferred image is excellent in mechanical abrasion resistance, etc., and printed by overlaying multiple color thermal transfer ink layers In some cases, the present invention relates to a thermal transfer recording medium and a thermal transfer recording method which have excellent color reproducibility so that the thermal transfer ink layer has good light transmittance and can form a clean layered structure.

[0002]

2. Description of the Related Art A thermal transfer recording system using a thermal head has been used for various purposes such as a label printer, a ticket issuing machine, and a word processor.
The environment in which printed materials are used as these applications expand,
It has been used in a more severe environment than the environment used conventionally.

[0003] Further, as the printed material is used in a more severe environment, the medium to be transferred is also changed from conventional paper and the like.
Its use in plastic films, which are less environmentally dependent, is expanding. If the medium to be transferred becomes special, conventional ribbons with a thermal transfer ink composition centered on wax will not be able to perform good transfer, or will transfer, but the printed matter will be removed by simple rubbing. However, problems such as not satisfying the mechanical abrasion resistance have arisen.

[0004] In particular, in the fields of printed matter, posters, signboards, and the like, which require a high-class feel, there are severe restrictions on the color reproducibility and color unevenness of the transferred matter. Did not.

Further, in the conventional thermal transfer ribbon, when the color is expressed by repeating the transfer onto the same transfer-receiving medium and overlapping the thermal transfer ink layers, the thermal transfer ink has a low softening point and a low viscosity at the time of melting. Therefore, when performing overprinting twice or more, due to the heat of the thermal head at the time of overprinting, the composition of the previously printed transfer ink layer is melted, and color unevenness due to ink mixing, Ink repelling occurs, and if the ink becomes more severe, problems such as the occurrence of untransferable objects have occurred.

As a countermeasure, all the inks to be transferred a plurality of times are immersed in the paper as the medium to be transferred to create a mixed state of the inks, and color expression is performed. Fine mechanical, such as lowering the transfer energy on the printer side according to the overlap and maintaining good transferability
Electric control was required. In addition, the number of transfer
Some attempts have been made to change the softening temperature of the ink layer to be transferred in accordance with the order to achieve both transferability and color reproducibility.

However, even if these measures are taken, it is good when the medium to be transferred is made of a material such as paper, but the absorption of thermal transfer ink such as a plastic base material during transfer is low. The material had drawbacks such as a poor effect.

[0008]

As described above, the environment in which a printed material obtained by thermal transfer printing using a thermal head is used in an environment that is more severe than the environment used conventionally. I have. For example, use under severe room temperature or use in an environment where printed matter is mechanically scratched.

Along with this, a special durable medium is used for the medium to be transferred as described above, and good transfer to a plastic film or the like, or only a printed matter is necessary. When obtaining a durable printed matter, and when expressing color by repeating the transfer on the same transfer medium and overlaying the thermal transfer ink layer, color unevenness due to ink mixing and ink repelling may occur However, problems such as poor fixability due to the overlapping of the inks have arisen.

That is, good thermal transfer can be performed on a transfer-receiving medium such as a durable plastic film, and the printed matter can be obtained while obtaining a printed matter having sufficient mechanical abrasion resistance. When color is expressed by repeatedly transferring the thermal transfer ink layer on the medium to express color, it is necessary to obtain a print that does not cause color unevenness due to ink mixing or ink repelling, and sufficient rub resistance even when ink is overlaid There is a major issue in obtaining a material that satisfies all of the requirements for having the property, and in order to achieve that issue, the thermal transfer ink layer component of the thermal transfer recording medium, the so-called ink ribbon, is considered to be the key to a major solution. Was. Although research on the composition of the transfer ink component has been conventionally performed, no proposal has been made yet to reach the level required for the present invention. The aim of the invention is to propose exactly this solution.

[0011]

In order to solve the above-mentioned problems, the present invention provides a thermal transfer recording medium having a thermal transfer ink layer having a specific viscoelastic property on a support, a thermal transfer recording method using the same, and As a result, the present invention has been completed. That is, the present invention provides: "1. In a thermal transfer recording medium having at least a thermal transfer ink layer provided on a support,
In a softened state over the entire temperature range of
A plurality of ink compositions exhibiting the following behaviors (a) and (b) in viscoelasticity measurement at a frequency of 1 Hz in a linear viscoelasticity range in the entire temperature range of 00 to 150 ° C.
The thermal transfer ink layer of the color of
Cormorant thermal transfer recording medium. (A) tan δ is 1 or more (b) Complex dynamic viscosity is 100 to 40,000 Pa · S 2. The thermal transfer recording medium according to claim 1, wherein the thermal transfer ink layer comprises at least a pigment and a vehicle, and the pigment comprises an organic pigment. 3. The thermal transfer ink layer comprises at least an inorganic pigment and a vehicle, and the ratio between the refractive index Np of the inorganic pigment and the refractive index Nr of the vehicle is in the range of Np / Nr = 1.12 to 1.00. 2. The thermal transfer recording medium according to claim 1, wherein 4. In the viscoelasticity measurement at a frequency of 1 Hz in the linear viscoelastic region in the softened state over the entire temperature range of 100 to 150 ° C and in the entire temperature range of 100 to 150 ° C, the following behaviors (a) and (b): A thermal transfer recording method in which a plurality of thermal transfer ink layers made of an ink composition are used and the thermal transfer ink layer is superimposed and transferred onto a transfer-receiving medium to perform multicolor printing. (A) tan δ is 1 or more (b) Complex dynamic viscosity is 100 to 40000 Pa · S At least consisting of a pigment and a vehicle, wherein the pigment is
5. The thermal transfer recording method according to claim 4, wherein a plurality of thermal transfer ink layers made of an organic pigment are used, and the thermal transfer ink layer is superimposed and transferred on a transfer-receiving medium to perform chromatic printing. 6. A plurality of thermal transfer ink layers comprising at least an inorganic pigment and a vehicle, wherein the ratio of the refractive index Np of the inorganic pigment to the refractive index Nr of the vehicle is in the range of Np / Nr = 1.12 to 1.00. 5. The thermal transfer recording method according to claim 4, wherein the thermal transfer ink layer is transferred onto the medium to be transferred in a superimposed manner to perform chromatic printing. ".

According to the above arrangement, when the thermal transfer recording medium is used to thermally transfer a plurality of colors onto a transfer-receiving medium such as a plastic substrate by using a thermal printer or the like, the transfer ink layers are respectively formed. In order to form a beautiful layered structure,
Good overprinting can be performed, and the printed image can be maintained in a good printing state without falling off or being damaged even by strong mechanical abrasion.

The thermal transfer ink layer of the present invention has a thickness of 100 to 15
In a temperature range of 0 ° C., it is in a softened state, and
Frequency 1 in the linear viscoelastic region in the temperature range of 50 ° C.
It consists of an ink composition having a tan δ of 1 or more and a complex dynamic viscosity of 100 to 40,000 Pa · S in viscoelasticity measurement at Hz.

Therefore, in the thermal transfer recording medium of the present invention,
When transferring the thermal transfer ink layer, the ink composition becomes a clean layered structure.When the same plastic substrate is used as the medium to be transferred, and the transfer is repeated to express the color by overlapping the thermal transfer ink layer. In this case, it is possible to obtain a print in which color unevenness due to ink mixing and ink repelling do not occur.

[0015] The thermal transfer ink layer is at 100 to 150 ° C.
Is required to be in a softened state over the entire temperature range.
In a part or the whole of this temperature range, a material having a high softening point that does not take a softened state, that is, maintains a solid state at a low temperature side during heating, can be sufficiently supplied with heat energy from a printer during transfer. Insufficiency of transfer occurs without softening to the extent that thermal transfer is possible, and the amount of energy at the time of transfer is insufficient, so that adhesion to the medium to be printed is deteriorated, and printing is dropped due to light mechanical abrasion.

Further, in a viscoelasticity measurement at a frequency of 1 Hz in a linear viscoelasticity range in a temperature range of 100 to 150 ° C., t
an δ is 1 or more, complex dynamic viscosity is 100 to 40,000
It is important that the thermal transfer ink composition has Pa · S.

Here, in the viscoelasticity measurement by a rheometer vibration method, when a sine wave force is applied to a sample, for example, the linear viscoelasticity region is defined as a torque, a frequency, and a gap between measurement geometry. And the like, where the conditions are appropriately set and the detected phase shift is obtained as a stable continuous sine wave. Further, the value of the complex dynamic viscosity obtained here indicates a value relatively close to the value of the viscosity obtained by a general rotation measurement method.

In the present invention, the frequency given to the measurement is 1
Hz is used as a representative. The reason is that it is considered that an appropriate frequency includes 1 Hz when an area similar to the behavior at the time of actual thermal transfer is assumed.

The tan δ in the viscoelasticity measurement is obtained by dividing the value of the loss elastic modulus by the value of the storage elastic modulus. If tan δ is large, the physical properties of the sample are said to have a large viscous component, and tan δ is small. If so, it means that the elastic component is large.

In the present invention, it is essential that the ink composition has a tan δ of 1 or more, that is, a relatively large viscous response. The ink composition having physical properties of tan δ of 1 or more upon heating and softening can obtain good transferability even on a transfer receiving medium such as a plastic film, which has conventionally been considered difficult to transfer, or when the transfer energy is somewhat insufficient. Above all, even when the color is expressed by repeating the transfer and overlapping the thermal transfer ink layer on the same transfer medium, the transfer ink layers each have a clean layered structure, without repelling ink, etc. With good scratch resistance can be obtained.

Conversely, if tan δ is less than 1, the elastic response becomes too strong, so that sufficient fluidity cannot be obtained for good transfer at the time of transfer, and the tendency for poor transfer to occur increases. . Further, even if the transfer can be performed, a problem arises because the transfer medium that can transfer well and the width of the printing energy are limited.

Further, the ink composition of the present invention is required to have a complex dynamic viscosity of 100 to 40,000 Pa · S as measured by viscoelasticity in a temperature range of 100 ° C. to 150 ° C. When it is within this range, the transfer ink layer forms a clean layered structure even when directly transferred onto the transfer medium,
Not only good transferability can be obtained, but also in the case of repeating transfer and overlaying the thermal transfer ink layer to express color, each can also form a clean layered structure, so that the amount of heat of the thermal head at the time of overprinting can be reduced. Therefore, the composition of the previously printed transfer ink layer is melted, so that color unevenness due to ink mixing and ink repelling do not occur, and the abrasion resistance of the overprinted one is also good. Color printing can be performed. Complex dynamic viscosity is 30
More preferably, it is 0 to 30,000 Pa · S.

Conversely, if the ratio is below this range, the fluidity at the time of heating and melting becomes too large and the thermal transfer ink layer after transfer cannot form a clean layered structure due to the transfer force applied at the time of transfer. Also, color unevenness occurs, which is not preferable. Furthermore, even in the case where the color is expressed by overlapping the thermal transfer ink layers, since the ink layer existing at the place to be transferred does not form a clean layered structure, irregularities are generated, and good thermal transfer is formed thereon. Is difficult to do. In addition, the composition of the previously printed transfer ink layer flows due to the amount of heat of the thermal head at the time of overprinting, causing color unevenness due to ink mixing, ink repelling, or overprinting. Subsequent abrasion resistance also tends to weaken, which is not preferable.

Above this range, the fluidity of the ink composition required for thermal transfer at the time of heating and melting cannot be obtained, and the tendency of poor transfer increases. Further, even if the transfer can be performed, there is a problem that a transfer medium that can transfer satisfactorily, a large print energy is required, and the like tend to cause a problem, which is not preferable.

In the present invention, the thermal transfer ink is adjusted to the above-described physical properties. The thermal transfer ink may be composed of a binder and a colorant having appropriate physical properties to make the above-mentioned physical properties. It can also be adjusted for the entire ink layer. In addition, in order to form a high-performance thermal transfer ink layer, it is necessary to consider its components.

The thermal transfer ink layer of the present invention preferably comprises at least a pigment and a vehicle. Pigments used include carbon black, ultramarine, chrome yellow, cadmium yellow, Hansa yellow, disazo yellow, permanent red, alizarin lake, quinacridone red, benzimidazolone red, victoria blue lake, phthalocyanine blue, phthalocyanine green, One or more pigments such as oxazine violet can be used. Pigments are preferred because they have good light fastness and good mechanical strength of the thermal transfer ink layer itself when printed matter is used in an environment irradiated with ultraviolet rays such as outdoor exposure.

In the thermal transfer recording medium of the present invention, since the thermal transfer ink layers to be transferred each have a good light transmittance, a printed matter having extremely excellent color reproducibility can be obtained at the overlapping portion of the transferred matter. be able to.

If the pigment is an organic pigment, its light transmittance is good. Therefore, even when the transfer is repeated and the thermal transfer ink layer is overlaid to express the color, the color tone of each layer is accurately expressed. In the overlapping portion, the color tone of each ink layer is uniformly and accurately obtained by the subtractive color mixture method, so that various chromatic colors can be expressed.

Further, when the pigment is an inorganic pigment, some pigments have poor light transmittance. When such a pigment is used, it is not easy to perform good overlapping multicolor printing. When an inorganic pigment is used as the pigment, it is preferable to use a combination of a pigment and a vehicle in which the ratio of the refractive index Np of the inorganic pigment to the refractive index Nr of the vehicle is in the range of Np / Nr = 1.12 to 1.00. Multicolor printing can be performed.

If the difference between the refractive indices of the two is larger than this range, the light transmittance deteriorates, that is, the concealing property of the thermal transfer ink layer becomes too large. When expressing, the ink layer outside the overlapped portion conceals the color tone of the previously transferred ink layer, making it impossible to accurately express the color of the previously transferred ink layer. It is not preferable because color mixing by the method cannot be obtained and a desired multicolor cannot be expressed.

Various resins and waxes can be used as a vehicle for the thermal transfer recording medium of the present invention. These can be used alone or in combination. Further, as each component of the plurality of thermal transfer ink layers used in the thermal transfer recording method of the present invention, different components can be used in each layer, or they can be composed of the same type of components. In terms of thermal sensitivity control and coating, it is preferable that the ink of each layer is composed of the same components.

The resin components used include vinyl chloride resin, polyamide resin, polyvinyl alcohol resin, acrylic resin, polyester resin, terpene resin, ethylene-methacrylic acid-acrylic acid copolymer, ethylene-
Thermoplastic resins such as vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, polystyrene-polyisoprene copolymers, rosin and its derivatives, phenolic resins, petroleum resins, and xylene resins can be blended.

Examples of the wax used include natural waxes such as paraffin wax, candelilla wax, microcrystalline wax, polyethylene wax, beeswax, carnauba wax, gay wax, mokurou, nuka wax, montan wax, ozokerite, ceresin, ester wax, and Fischer-Trops wax. Or synthetic waxes, higher fatty acid waxes such as myristic acid, palmitic acid, stearic acid, furomenic acid, behenic acid, lauric acid and margaric acid; and amide waxes such as stearinamide and oleinamide.

The thermal transfer recording method of the present invention can be performed well by using a plurality of the above-described thermal transfer recording media of the present invention and repeating the transfer to superimpose the thermal transfer ink layer to express the color.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer recording medium and the thermal transfer recording method of the present invention will be specifically described below.

As the support of the thermal transfer recording medium, various types of conventionally known plastic films can be used. The thermal transfer recording medium of the present invention has a heat-resistant lubricating layer on the back side of 2.5 to 6.0 μm. A degree of polyester film can be used.

The thermal transfer recording medium of the present invention is provided on a support.
Although it is configured by providing the thermal transfer ink layer,
There are no particular restrictions on the ink layer production method, and the ink layer is dispersed and dissolved in an aqueous or oil-based solvent to prepare a coating solution, which is required by a coating method such as a gravure coater, a wire bar coater, and an air knife coater. And a thermal transfer recording medium can be obtained.

When a thermal transfer ink layer is provided on a support, a single-color thermal transfer ink may be applied to the entire surface of the support to form a monocolor ribbon. May be sequentially provided in a block shape.

In order to carry out the thermal transfer recording method of the present invention,
The above-described thermal transfer recording medium of the present invention is used. When using a monocolor ribbon coated with a single color thermal transfer ink on the entire surface of the support, when printing with one thermal head, print with the first ribbon, then change the ribbon, The printed medium to be transferred is pulled back, and an operation for printing with the second ribbon is performed. When printing three or more colors, the same operation is performed in order, and multicolor thermal transfer recording can be performed.

When a ribbon in which transfer ink layers of a plurality of colors are sequentially provided in a block on one support is used, a special printer is required. It can be performed.

The thermal transfer ink composition of the present invention further contains additives to improve various properties such as print abrasion resistance, ribbon running property, and ribbon preservability, as long as the basic performance of the present invention is not reduced. You may. The amount varies depending on the type of the additive, but may be 2 to the entire thermal transfer ink.
It is preferably 0% by weight or less.

The coating thickness of the thermal transfer ink layer is 1.0 to 3.0.
About μm is preferable for good color expression including overprinting.

In the thermal transfer recording medium of the present invention, it is essential to provide a thermal transfer ink layer on a support, but other methods such as providing a functional layer such as a release layer between the support and the thermal transfer ink layer are also required. A layer may be provided.

[0043]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples. In the examples and comparative examples, all “parts” are by weight unless otherwise specified.

Example 1 A heat-resistant lubricating layer was formed on one side of a 4.5 μm-thick polyester film to provide a support, and a heat-transfer ink layer component having the following constitution was applied on the opposite side of the heat-resistant lubricating layer of the support. It was prepared so as to have a solid content of 30% in a solvent of toluene / methyl ethyl ketone (5.5 ratio), and was coated with a gravure coater to a coating thickness of 2.0%.
The coating was dried to a thickness of μm and dried to produce a black thermal transfer ink layer. (Thermal transfer ink layer components) PVC / vinyl acetate / hydroxy acrylate resin (Note 1) 60 parts Polyethylene wax (Note 2) 15 parts Carbon black 20 parts Dispersant 5 parts (Note 1) Glass transition point 53 ° C, molecular weight 5500 (Note) 2) Polyethylene wax having a melting point of 110 ° C. The viscoelasticity measured at 100 to 150 ° C. of the above thermal transfer ink is as follows: tan δ = 2.12 to 2.59, complex dynamic viscosity = 1300 to 10800 Pa · S
Met.

Example 2 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to form a cyan thermal transfer ink layer, and a thermal transfer recording medium was obtained. (Thermal transfer ink layer component) Polyester resin (Note 3) 60 parts Polyethylene wax (Note 2) 15 parts Phthalocyanine blue (organic pigment) 20 parts Dispersant 5 parts (Note 3) Glass transition point 55 ° C, molecular weight 5000 The measured values in the viscoelasticity measurement at 100 to 150 ° C. were tan δ = 1.48 to 2.88 and complex dynamic viscosity = 630 to 30000 Pa · S.

Example 3 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to prepare a magenta thermal transfer ink layer, and a thermal transfer recording medium was obtained. (Thermal transfer ink layer component) Polyester resin (Note 3) 60 parts Polyethylene wax (Note 2) 15 parts Quinacridone red (organic pigment) 8 parts Benzimidazolone red (organic pigment) 12 parts Dispersant 5 parts The measured values in the viscoelasticity measurement at 150 ° C. were: tan δ = 1.48 to 2.88, complex dynamic viscosity = 630 to 30000 Pa · S.

Example 4 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to prepare a yellow thermal transfer ink layer, and a thermal transfer recording medium was obtained. (Thermal transfer ink layer component) Polyester resin (Note 3) 60 parts Polyethylene wax (Note 2) 15 parts Disazo yellow (organic pigment) 20 parts Dispersant 5 parts The viscoelasticity of the above thermal transfer ink at 100 to 150 ° C was measured. Tan δ = 1.48 to 2.88, complex dynamic viscosity = 630 to 30000 Pa · S.

Example 5 In the same manner as in Example 1, a thermal transfer ink layer component having the following constitution was formed on a support to form a blue thermal transfer ink layer, and a thermal transfer recording medium was obtained. (Thermal transfer ink layer components) PVC / vinyl acetate / hydroxy acrylate resin (Note 1) 65 parts Polyethylene wax (Note 2) 10 parts Ultramarine (Note 4) 20 parts Dispersant 5 parts (Note 4) Inorganic pigment, refractive index (Np ) = 1.56 Refractive index of the vehicle (Nr) = 1.53 Np / Nr = 1.02 The viscoelasticity measured at 100 to 150 ° C. of the thermal transfer ink is tan δ = 2.92 to 3.47, Complex dynamic viscosity = 700 to 10000 Pa · S.

Example 6 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to prepare a purple thermal transfer ink layer, and a thermal transfer recording medium was obtained. (Thermal transfer ink layer components) PVC / vinyl acetate / hydroxy acrylate resin (Note 1) 55 parts Polyethylene wax (Note 2) 10 parts Dioxacin violet (organic pigment) 20 parts Extender pigment (Note 5) 10 parts Dispersant 5 parts (Note 5) Calcium carbonate powder (inorganic pigment), refractive index (Np) = 1.60 Refractive index of vehicle (Nr) = 1.53 Np / Nr = 1.05 Viscoelasticity of the above thermal transfer ink at 100 to 150 ° C The measured value in the measurement was tan δ = 2.00 to 2.60 complex dynamic viscosity = 1500 to 12000 Pa · S.

Comparative Example 1 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to prepare a blue thermal transfer ink layer, and a thermal transfer recording medium was obtained. Styrene acrylic resin (Note 6) 10 parts Coumarone resin (Note 7) 25 parts Polyethylene wax (Note 2) 20 parts Carnauba wax 20 parts Phthalocyanine blue (organic pigment) 20 parts Dispersant 5 parts (Note 6) Glass transition point 57 ° C, molecular weight 1600 (Note 7) Softening point 100 ° C, molecular weight 640 The viscoelasticity measured at 100 to 150 ° C of the thermal transfer ink is tan δ = 1.70 to 11.4 Complex dynamic viscosity = 5 to 15 Pa -It was S.

Comparative Example 2 In the same manner as in Example 1, a thermal transfer ink layer component having the following constitution was formed on a support to prepare a blue thermal transfer ink layer, and a thermal transfer recording medium was obtained. PVC / vinyl acetate / vinyl alcohol copolymer (Note 8) 65 parts Polyethylene wax (Note 2) 10 parts Phthalocyanine blue (organic pigment) 20 parts Dispersant 5 parts (Note 8) Glass transition point 70 ° C, molecular weight 20,000 The above thermal transfer The measured value in the viscoelasticity measurement of the ink at 100 to 150 ° C. is: tan δ = 0.26 to 1.40 Complex dynamic viscosity = 7000 to 60000 Pa · S
Met.

Comparative Example 3 In the same manner as in Example 1, a thermal transfer ink layer having the following constitution was formed on a support to prepare a blue thermal transfer ink layer, and a thermal transfer recording medium was obtained. PVC / vinyl acetate / hydroxy acrylate copolymer (Note 9) 65 parts Polyethylene wax (Note 2) 10 parts Phthalocyanine blue (organic pigment) 20 parts Dispersant 5 parts (Note 9) Glass transition point 65 ° C, molecular weight 15,000 Thermal transfer above The measured value in the viscoelasticity measurement of the ink at 100 to 150 ° C. is: tan δ = 0.53 to 8.10. Complex dynamic viscosity = 4300 to 71000 Pa · S
Met.

Example 7 The cyan, magenta, and yellow thermal transfer inks described in Examples 2, 3, and 4 were sequentially applied in the form of blocks using a gravure coater on the same support as in Example. Thus, a three-color thermal transfer recording medium was obtained.

The thermal transfer recording medium prepared as described above is heated
Attached to the transfer printer, white polyester label, salt
Billabelle, yupo label, peach coat label, silver namema
8 dots / mm, 0.2
~ 0.4mj / dot, 2inch / min printing conditions
Including random overprinting with each thermal transfer recording medium
Printing was performed to obtain a printed matter. Table 1 shows the printing results.

Example 8 The thermal transfer recording medium of Example 2 was mounted on a thermal transfer printer.
And 8 dots / mm, 0.2
~ 0.4mj / dot, 2inch / min printing conditions
After printing on the thermal transfer recording medium of Example 3,
Replace the thermal transfer ink of Example 3 on the same label
And printed to obtain a multicolor printed matter.

Embodiment 9 The thermal transfer recording media of Embodiments 2, 3 and 4
Multi-head thermal transfer printer with three print heads
On the white polyester label, 8 dots /
mm, 0.2-0.4 mj / dot, 2 inch / mi
Under the printing conditions of n, put each ink layer on the same label.
Overprinting was performed to obtain a multicolor printed matter.

Example 10 A thermal transfer printing medium for multicolor printing was prepared by using the thermal transfer recording medium of Example 7
8 dots / m on white polyester label
m, 0.2-0.4 mj / dot, 2 inch / min
Transfer the ink layer of the cyan block under the printing conditions of
After rewinding the label, insert the magenta block
The transfer layer is partially overlapped with the cyan transfer material and transferred.
After rewinding the label as above,
Ink layer partially overlaps the transferred ink layer
To obtain a multicolor print on the same label.

[0058]

[Table 1] Here, primary transferability, transferability and color expression in superimposed printing as the first printing, and abrasion resistance of printed matter were evaluated by the following test methods. Primary transferability: After printing on an unprinted transfer medium with a thermal transfer printer, the printed matter was magnified with a microscope of 50 times, and it was visually observed whether or not the printed pattern was faithfully transferred to the printed pattern. Transferability in overprinting: After printing on the thermal transfer ink of the transfer medium that has already been thermally transferred by the thermal transfer printer, the printed matter is magnified with a microscope of 50 times and transferred to the printed pattern visually. I saw whether it was. Expression of colors in overprinting: After printing on the thermal transfer ink of the transfer medium that has already been thermally transferred by the thermal transfer printer, whether the printed matter expresses the desired color by the subtractive color mixing method, I saw if there were any irregularities. Abrasion resistance of printed matter: After printing was performed with a thermal transfer printer, the state of the printed matter was observed when the printed matter was rubbed 100 times with a 1 cm square felt / φ2 mm steel ball under a load of 200 g.

As is clear from Table 1, the printed matter printed by the thermal transfer recording medium of the present invention shown in Examples 1 to 6 and the printed matter printed by the printing method of Examples 7 to 10 are: All of these are thermal transfer recording media having excellent primary transferability, good transferability and color reproducibility in overprinting, and excellent abrasion resistance of printed matter.

[0060] In contrast, the printed matter by thermal transfer recording medium of Comparative Example 1, the abrasion resistance of the printed matter is weak, the primary transfer resistance or cause transfer chipping, those transfer unevenness is good quality with or occur Could not be obtained. Regarding transferability and color reproducibility in overprinting, if reprinting is performed on these ink layers, these ink layers will melt, causing color unevenness due to ink mixing and transfer failure due to ink repelling. It was observed.

For the thermal transfer recording media of Comparative Examples 2 and 3, the transferability was poor because the elastic response was too strong when heated .
Was. The abrasion resistance of the transferred area is relatively good.
Was.

[0062]

As described above, the thermal transfer recording medium of the present invention comprises a thermal transfer recording medium having a thermal transfer ink layer having a specific viscoelastic property on a support and a thermal transfer recording method using the same. Because of this, good printing can be performed even on a printing medium that has a surface state that is difficult to thermally transfer, and even when multiple colors are superimposed and thermally transferred, the transfer ink layers each have a clean layered structure, Printing can be performed, and an excellent effect of maintaining a good printing state without dropping or damaging the image after printing due to strong mechanical abrasion or the like can be obtained.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 1-258987 (JP, A) JP-A 8-52942 (JP, A) JP-A 2-29387 (JP, A) JP-A 3-29387 99885 (JP, A) JP-A-62-13383 (JP, A) JP-A-62-13384 (JP, A) JP-A-63-230392 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) B41M 5/38-5/40

Claims (6)

(57) [Claims] 1. In a thermal transfer recording medium having at least a thermal transfer ink layer provided on a support, the thermal transfer ink layer is in a softened state over the entire temperature range of 100 to 150 ° C. and has a temperature range of 100 to 150 ° C. A thermal transfer ink layer of a plurality of colors, characterized by being composed of an ink composition exhibiting the following behaviors (a) and (b) in a viscoelasticity measurement at a frequency of 1 Hz in a linear viscoelastic region in the entire region, and printing by superimposing:
Thermal transfer recording medium for multi-color printing . (A) tan δ is 1 or more (b) Complex dynamic viscosity is 100 to 40,000 Pa · S 2. A thermal transfer ink layer comprising at least a pigment and a vehicle, wherein the pigment comprises an organic pigment.
3. The thermal transfer recording medium according to 1. 3. A thermal transfer ink layer comprising at least an inorganic pigment and a vehicle, wherein the ratio of the refractive index Np of the inorganic pigment to the refractive index Nr of the vehicle is in the range of Np / Nr = 1.12 to 1.00. 2. The thermal transfer recording medium according to claim 1, wherein: In 4. There softened at a temperature range throughout the 100 to 150 ° C., and viscoelasticity measurement frequency 1Hz in the linear viscoelastic region definitive <br/> the temperature range throughout the 100 to 150 ° C., below (A) A thermal transfer recording method in which a plurality of thermal transfer ink layers made of an ink composition exhibiting the behavior of (b) are used, and the thermal transfer ink layer is transferred onto a medium to be transferred in a superimposed manner to perform multicolor printing. (A) tan δ is 1 or more (b) Complex dynamic viscosity is 100 to 40,000 Pa · S 5. It comprises at least a pigment and a vehicle,
The thermal transfer recording method according to claim 4, wherein the thermal transfer ink layer is formed by using a plurality of thermal transfer ink layers made of an organic pigment, and the thermal transfer ink layer is superimposed and transferred on a medium to be transferred, thereby performing chromatic printing.
Law . 6. A thermal transfer ink layer comprising at least an inorganic pigment and a vehicle, wherein the ratio of the refractive index Np of the inorganic pigment to the refractive index Nr of the vehicle is in the range of Np / Nr = 1.12 to 1.00. 5. The thermal transfer recording method according to claim 4, wherein a plurality of the thermal transfer ink layers are used to transfer the thermal transfer ink layer on the transfer medium in a superimposed manner, thereby performing chromatic printing.