JPH09323480A - Thermal transfer ink and thermal transfer ink ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer ink ribbon capable of obtaining a clear transfer image having excellent transferability and high durability. SOLUTION: When a heat transfer ink ribbon 1 is constituted by forming an ink layer 13 containing a heat fusible resin binding material as a main component, the layer 13 contains low lubricity fine particles not softened at the temperature of softening the material. Since the heat fusible resin is used, the durability of the image is high. Since it contains the particles, the sharpness is excellent. Since the particles have low lubricity, no slip occurs. The mean particles size of the particles is 0.3 to 3.0μm, a benzoguanamine formaldehyde condensation resin particle, melamine formaldehyde condensation resin particle, benzoguanamine melamine formaldehyde condensation resin particle or tetrafluoro ethylene resin particle is used, and it is contained in an amount of 10 to less than 60wt.%, desirably 20 to 50wt.%, in the ink layer 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer ink useful for thermal transfer recording using a thermal head or the like, and a thermal transfer ink ribbon using the thermal transfer ink.

[0002]

2. Description of the Related Art At present, a thermal transfer recording system using a heating element such as a thermal head is widely used in recording devices such as printers such as computer terminals, word processors, facsimiles and copying machines. Such thermal transfer recording methods include a recording method using a thermal paper and a recording method using a thermal transfer ink ribbon.

A method using a thermal transfer ink ribbon is called a thermal fusion transfer recording method, in which an ink layer is formed on a tape-shaped base material, and the transferred material such as paper (print medium) is formed on the ink layer. ) Is adhered, a thermal head is applied to the back surface of the substrate to generate heat, and the ink layer is melted by heat and transferred to the transfer target.
A binder material whose main component is wax, such as colorants and fillers
(Hereinafter, referred to as a binder) is given moldability,
It is formed to have a thickness of several μm on the base material.

In recent years, transfer images printed using such a thermal transfer ink ribbon are required to have high sharpness, and the sharper the ink layer is, the clearer the transfer image can be obtained. In thermal transfer ink ribbons that use wax as the main component of the binder, attempts have been made to improve the cutting performance by adding fine particles of a thermosetting resin such as silicone resin to the ink layer, and a certain effect has been achieved. It is reported that there is (JP-A-3-239589).

However, when wax is used as the main component of the binder, the transferred image formed on the transferred material by thermal transfer is inferior in heat resistance, abrasion resistance and the like, and durability is insufficient.

Therefore, it has been considered to use a heat-melting resin, that is, a thermoplastic resin, as a main component of the binder, instead of wax. However, when a thermoplastic resin is used, the heat resistance and abrasion resistance of the transferred image are improved, but the sharpness of the ink layer at the time of transfer is reduced, and the portion heated by the thermal head is not heated. The ink layer does not cut sharply at the boundary with the
There has been a problem that a clear transferred image cannot be obtained.

Therefore, the inventors of the present invention have proposed a thermal transfer ink ribbon described in Japanese Patent Laid-Open No. 5-286272 in order to solve the problem of the cutting property. In the thermal transfer ink ribbon described in that publication, the ink layer is formed by further containing fluorine-containing resin particles or silicone resin particles in addition to the colorant and the thermoplastic resin, and the heat resistance and abrasion resistance of the transferred image are improved. While maintaining the above, the sharpness of the ink is improved and a clear transferred image can be obtained.

However, in the above-mentioned thermal transfer ink ribbon, when the transfer target is a label, the transferred image may be clear or unclear depending on the type of the label, and the print quality may not be constant. is there. There are many causes of unclear transfer images, but investigation and countermeasures are required.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to solve the above disadvantages of the prior art, and the first object of the present invention is to provide a thermal transfer ink ribbon capable of obtaining a clear transferred image. To do. A second object is to provide a thermal transfer ink ribbon having a high durability such as heat resistance and abrasion resistance of a transferred image. A third problem is to provide a thermal transfer ink ribbon having good transferability.

[0010]

Generally, when printing is performed on a transfer target by a thermal transfer ink ribbon, the thermal transfer ink ribbon and the transfer target are brought into contact with each other and the transfer target is run by an internal mechanism of the printer. Thus, the thermal transfer ink ribbon is configured to run due to the friction of the contact surface. However, the inventors of the present invention have disclosed the above-mentioned Japanese Patent Laid-Open No. 5-28627.
In the thermal transfer ink ribbon as described in Japanese Patent Laid-Open No. 2 (1993), when the cause of unclear transfer image is pursued, the thermal transfer ink ribbon slips on the surface of the transfer target when the transfer image is printed. It was found that the normal running of the ink ribbon was not performed.

In the case of a thermal transfer ink ribbon whose binder is mainly composed of wax, the ink layer becomes soft and the adhesiveness is not deteriorated even when printing is performed on a transfer target having large surface irregularities. Driveability was never an issue. On the other hand, in the thermal transfer ink ribbon containing a heat-meltable resin as the main component of the binder, the ink layer becomes hard and the adhesion becomes sensitive to the unevenness of the transfer target. Therefore, the adhesiveness between the transfer target and the transfer target having large irregularities becomes insufficient, and as a result, the frictional force becomes small.

The inventors of the present invention have found that in a thermoplastic resin,
Slip occurs when an ink layer is formed by adding fluororesin particles or silicone resin particles together with a colorant,
Fine particles with low friction force are added to the ink layer with low friction force, and the friction coefficient on the surface of the ink layer becomes smaller than that without fine particles, which may cause slippage depending on the type of transfer target. It was found to be the cause.

Therefore, as a countermeasure, when the main component of the binder of the thermal transfer ink is a hot-melt resin,
If the fine particles to be contained in the ink layer are selected to have low lubricity, the friction coefficient on the surface of the ink layer will be increased and slip will not occur. In this case, the low-slipping particles,
It is expected that good breakability of the ink layer during transfer will be maintained.

The structure of the present invention is created on the basis of the above-mentioned findings in order to solve the above problems, and the invention according to claim 1 thereof is one in which a hot-melt resin is used as a binder material. It is a thermal transfer ink containing a main component, and is characterized by containing low-sliding fine particles composed of a heat-resistant material that does not soften at a temperature at which the binder material softens.

In this case, as in the invention described in claim 2,
The low-slidability fine particles may be composed of one or more particles of benzoguanamine / formaldehyde condensation resin particles, melamine / formaldehyde condensation resin particles, benzoguanamine / melamine / formaldehyde condensation resin particles, or tetrafluoroethylene resin particles. it can.

Such low-slidability fine particles can be contained in the thermal transfer ink in a range of more than 10% by weight and less than 60% by weight as in the third aspect of the invention.

In this case, as in the invention described in claim 4,
In particular, it is preferable that the content is 20% by weight or more and 50% by weight or less.

Further, as in the invention described in claim 5, the low-slipperiness fine particles can have an average particle diameter of 0.3 μm or more and 3.0 μm or less.

With respect to the thermal transfer ink according to any one of claims 1 to 5 described above, as in the invention according to claim 6, the thermal transfer ink is formed as a heat-meltable ink layer on a substrate. It is also possible to construct a thermal transfer ink ribbon.

According to such a constitution of the present invention, the low-slipping fine particles contained in the ink layer are binder (binder material).
Since it does not soften at the temperature at which the hot-melt resin, which is the main component of the ink, softens, it is thermally stable and does not soften at the time of thermal transfer, and the sharpness of the ink layer can be improved. Furthermore, since the surface of the low-activity fine particles has a large friction coefficient (low slipperiness), the ink layer and the transferred material do not slip, and a transferred image with high print quality can be obtained.

The above-mentioned low-slipping particles are resin particles other than fluorine-containing resin particles or silicon resin particles, such as acrylic resin particles, methacrylic resin particles, styrene resin particles, epoxy resin particles, tetrafluoroethylene resin particles, and benzo. Guanmin-formaldehyde condensation resin particles, melamine
Low-slip resin particles such as condensation particles obtained by condensation polymerization reaction such as formaldehyde condensation resin particles and benzoguanmine / melamine / formaldehyde condensation resin particles can be widely used. Among them, it is possible to use condensed resin particles that are stable at the temperature at which the hot-melt resin softens.

The addition ratio to be contained in the ink layer is as follows.
If it is 10% by weight or less, the amount of slippage is large, and if it is 60% by weight or more, the thermal sensitivity becomes dull and the load on the thermal head becomes large. In particular, it is desirable to set it in the range of 20 wt% or more and 50 wt% or less.

Further, it is desirable that the average particle diameter of the low-slipping fine particles is not excessive with respect to the thickness of the ink layer. Practically, the thickness of the ink layer is 0.3 μm to 1
The thickness is usually 0.0 μm, and the average particle size of the low-sliding fine particles is preferably smaller than the thickness of the ink layer to be contained, and more preferably 0.3 μm to 3.
It is preferable that the average particle size is 0 μm.

The hot-melt resin used as the main component of the binder of the thermal transfer ink has a melting point of at least 150.
Those having a temperature of ℃ or less, preferably 120 ℃ or less, most preferably 100 ℃ ~ 120 ℃, specifically, polyester resin, polyamide resin, acrylic resin, vinyl chloride resin, EEA (ethylene ethyl acrylic acid copolymer (Combined), EVA (ethylene vinyl acetate copolymer), terpene, petroleum resin, SIS (styrene isoprene styrene copolymer), SBS (styrene butadiene styrene copolymer), etc. be able to. When these heat-meltable resins are used as the main component of the binder, compared to the case where wax is used, the durability of the transferred image such as heat resistance and abrasion resistance is excellent, and good cuttability of the ink layer and Together, it is possible to obtain a clear transfer image with high print quality.

As the colorant contained in the thermal transfer ink, pigments and dyes conventionally used in the thermal fusion transfer recording system can be widely used. For example, one or more of carbon black, fast yellow G, disazo yellow AAA, brilliant carmine 6B, phthalocyanine blue, titanium oxide, bronze, aluminum and the like can be used.

As the components of the thermal transfer ink, waxes such as carnauba wax, candelilla wax, beeswax, and paraffin wax, a plasticizer, a dispersant and the like can be appropriately blended, if necessary.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The thermal transfer ink ribbon of the present invention is shown by reference numeral 1 in FIG. This thermal transfer ink ribbon 1 includes a release layer 12 and a heat-meltable ink layer 1 on a surface of a sheet-shaped substrate 11.
3 is laminated in this order, a transfer target such as recording paper is brought into close contact with the heat-meltable ink layer 13, and the heat-meltable ink layer 13 is heated by a thermal head closely arranged on the back surface of the ink ribbon 1. When melted, the presence of the peeling layer 12 allows the thermal transfer ink to be uniformly transferred to the transfer target with low energy, so that a transfer image can be formed.

At this time, since the protective layer 14 is provided on the back surface of the base material 11, sticking does not occur even when the thermal head is brought into close contact with the protective layer 14 side, and the thermal transfer ink ribbon 1 is smooth. It is designed to ensure good driving.

The base material 11 is made of a polyester film, but a polyimide film, condenser paper or the like may be used. Further, the peeling layer 12 contains a wax such as carnauba wax and candelilla wax as a main component and has a melting point of 50 ° C. to 100 ° C.
A material that easily peels off when heat is applied is used. Further, although the protective layer 14 is formed of a silicone resin, it is also possible to use a resin having excellent heat resistance such as a fluororesin or a nitrocellulose resin.

Regarding the thickness of each layer, the substrate 11 is 3.0 to 10.0 μm, and the release layer 12 is 0.1 to 3.0 μm.
m, the heat-meltable ink layer 13 is 0.3 to 10.0 μm, and the protective layer is 0.05 to 1.00 μm.
Hereinafter, a specific description will be given based on examples.

[0031]

【Example】

<Example 1> Eposter S6 (Melamine-formaldehyde condensation resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 3% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 21% by weight, MEK: 70% by weight, and first a thermal transfer ink was prepared.

Next, a polyester film having a thickness of 5.0 μm is used as the base material 11, a protective layer 11 made of an acrylic-silicone resin is provided on the back surface of the base material 11, and an ester wax: 90 wt%, ethylene-vinyl acetate-copolymer. 1. The release layer 12 of 10% by weight is provided, and the thermal transfer ink described above is applied onto the release layer 12 and after drying, 2.
The heat-meltable ink layer 13 having a thickness of 0 μm was formed to prepare the thermal transfer ink ribbon 1.

A polyester label (manufactured by Lintec Co., Ltd., 50 WH) was used as the transferred material, and the obtained thermal transfer ink ribbon 1 and a bar code printer (manufactured by Autonics Co., Ltd.,
Printing was performed by using BC-8mkII), and thermal sensitivity, printing quality, and ribbon slip amount at that time were evaluated.

In this parcode printer, as shown in FIG. 2, the thermal transfer ink ribbon 1 and the transferred material 24 are sandwiched between the thermal head 22 and the platen in this order, and the platen 23 is rotated to Since printing and ribbon feeding are performed by running the transfer body 24, when slippage occurs between the thermal transfer ink ribbon 1 and the transfer target 24, the travel distance of the transfer target 24 is larger. Become. In addition,
The thermal head 22 is configured so that 8 dots can be printed within a width of 1 mm.

[0035]

【Example】

<Example 2> Eposter S6 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 18% by weight, MEK: 70% by weight to prepare a thermal transfer ink, and the same as in Example 1. A thermal transfer ink ribbon 1 was prepared and evaluated.

[0036]

【Example】

<Example 3> Eposter S6 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 9% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 15% by weight, MEK: 70% by weight to prepare a thermal transfer ink, and the same as in Example 1. A thermal transfer ink ribbon 1 was prepared and evaluated.

[0037]

【Example】

<Example 4> Eposter S6 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 12% by weight, carbon black: 6% by weight,
Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 12% by weight and MEK: 70% by weight were mixed to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0038]

【Example】

<Example 5> Eposter S6 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 15% by weight, carbon black: 6% by weight,
Elitel UE3380 (a polyester resin manufactured by Unitika Ltd.): 9% by weight and MEK: 70% by weight were mixed to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0039]

【Example】

<Example 6> Eposter S6 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size of 0.
6 μm): 15% by weight, carbon black: 6% by weight,
Elitel UE3380 (a polyester resin manufactured by Unitika Ltd.): 9% by weight and MEK: 70% by weight were mixed to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0040]

【Example】

<Example 7> Eposter S (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle size 0.3)
μm): 6% by weight, carbon black 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.) 18% by weight, MEK 70% by weight to prepare a thermal transfer ink, and the thermal transfer ink ribbon was prepared in the same manner as in Example 1. 1 was prepared and evaluated.

[0041]

【Example】

<Example 8> Eposter S12 (melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle diameter 1.2 μm): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): The thermal transfer ink was prepared by blending 18% by weight and MEK: 70% by weight, and the thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0042]

【Example】

<Example 9> Eposter MS (Nippon Shokubai Co., Ltd. benzoguanamine / formaldehyde condensed resin particles, average particle diameter 2.0 μm): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin by Unitika Ltd.): 18% by weight and 70% by weight of MEK were blended to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0043]

【Example】

<Example 10> Eposter M30 (Benzoguanamine / melamine / formaldehyde condensed resin particles manufactured by Nippon Shokubai Co., Ltd., average particle diameter 3.0 μm): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.) ): 18% by weight, ME
K: 70% by weight was blended to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0044]

【Example】

<Example 11> Eposter MA1001 (Polymethyl methacrylate resin particles manufactured by Nippon Shokubai Co., Ltd., average particle diameter 1)
~ 2 μm): 6% by weight, carbon black: 6% by weight,
Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 18 wt% and MEK: 70 wt% were blended to prepare a thermal transfer ink, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 1.

[0045]

【Example】

<Comparative Example 1> Carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.):
A thermal transfer ink was prepared by blending 24% by weight and MEK: 70% by weight, and a thermal transfer ink ribbon 1 was prepared and evaluated in the same manner as in Example 2.

<Comparative example 2> KTL-8 (tetrafluoroethylene resin particles manufactured by Kitamura Co., Ltd., average particle diameter 3.0 μm)
m): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 18% by weight, MEK: 70% by weight to prepare a thermal transfer ink, and the same as in Example 1. A thermal transfer ink ribbon 1 was prepared and evaluated.

Comparative Example 3 Tospearl 108 (Silicone resin particles manufactured by Toshiba Silicone Co., Ltd., average particle diameter of 0.
8 μm): 6% by weight, carbon black: 6% by weight, Elitel UE3380 (polyester resin manufactured by Unitika Ltd.): 18% by weight, MEK: 70% by weight to prepare a thermal transfer ink, and the same as in Example 1. A thermal transfer ink ribbon 1 was prepared and evaluated.

<Evaluation Results> These evaluation results are shown in Table 1 below.
Shown in

[0049]

[Table 1]

The print result at 20 mj / mm ² is the print result when the heat generation amount of the thermal head 22 is set to be the same value, and when the void (white spot) is not visually observed, ◯, when observed, was evaluated as x.

However, even if voids are not observed, if the optimum thermal energy value is too low, 20
In the case of printing with an energy of mj / mm ^2, the print was blurred due to excessive energy, and the printed product was deteriorated.

Table 1 shows the thermal head 2 when the print result of the best quality as the optimum heat energy is obtained.
The set value of 2 is read and converted into thermal energy and described. It is generally said that the optimum thermal energy is 20 mj / mm ² or less because the thermal head will be damaged if it is too large.

The trailing length indicates whether or not the cutting property of the heat-meltable ink layer is good, and the smaller the length, the sharper the transferred image and the better the printing quality. In Table 1, those having a trailing length of 10 μm or less are marked with “◯” because the print quality is good, while those with a trailing length of 10 μm or more are marked as “poor”.

The amount of slippage is 10 when the traveling distance of the transferred body 24 is 10.
The running distance of the thermal transfer ink ribbon 1 when the distance is cm is shown. As the results of slip evaluation, ○ was entered for those with a running difference of less than 2.0%, △ for those with 2.0% or more and less than 5.0%, and × for those with 5.0% or more. . In each of the examples and the comparative examples, the same polyester label was used as the transfer target 24.

As is clear from the results shown in Table 1,
The thermal transfer ink ribbons (Examples 1 to 11) using the thermal transfer ink of the present invention use a heat-fusible resin as the main component of the binder, and thus have excellent durability such as heat resistance and abrasion resistance of printed matter. ing. Moreover, since the low-slidability fine particles are contained, the sharpness at the time of transfer is sharp, and a clear and high-print quality transferred image is obtained.

The above is a benzoguanamine / formaldehyde condensation resin, a melamine / formaldehyde condensation resin,
Or, select one type from benzoguanamine / melamine / formaldehyde condensation resin to form low lubricity fine particles,
Although it is contained in the heat-meltable ink layer, it may be contained in one heat-meltable ink layer by selecting two or more kinds of particles to form low-slidability fine particles. Incidentally, the shape of the low-slidability fine particles is preferably spherical, but, for example, a flaky shape or an amorphous shape,
It goes without saying that various types can be used.

[0057]

Since the main component of the binder of the thermal transfer ink is the thermoplastic resin, the durability of the transferred image such as heat resistance and abrasion resistance is high. Since the low-slidability fine particles are contained, the ink cuttability is good, and since a slip during transfer does not occur, the transferred image is clear. It has good thermal transferability and is easy to use.

[Brief description of drawings]

FIG. 1 is an example of a thermal transfer ink ribbon of the present invention.

FIG. 2 is a diagram for explaining a measurement method

[Explanation of symbols]

1 ... Thermal transfer ink ribbon 11 ... Base material 12 ...
… Peeling layer 13 …… Heat-melting ink layer 14 …… Protective layer 22 …… Thermal head 23 …… Platen 24 …… Transfer material

Claims (6)

[Claims] 1. A thermal transfer ink containing a heat-fusible resin as a main component of a binder material, which contains low-sliding fine particles composed of a heat-resistant material that does not soften at a temperature at which the binder material softens. Thermal transfer ink. 2. The low-slidability fine particles are benzoguanamine / formaldehyde condensed resin particles, melamine / formaldehyde condensed resin particles, benzoguanamine / melamine.
The thermal transfer ink according to claim 1, which is composed of one or more particles of formaldehyde condensed resin particles or tetrafluoroethylene resin particles. 3. The thermal transfer ink according to claim 1, wherein the low-slipping fine particles are contained in a range of more than 10% by weight and less than 60% by weight. 4. The low-lubricity fine particles are contained in an amount of 20% by weight or more and 5
The thermal transfer ink according to claim 1, wherein the thermal transfer ink is contained in an amount of 0% by weight or less. 5. The average particle diameter of the low-slipping fine particles is 0.3 μm.
m or more and 3.0 μm or less.
5. The thermal transfer ink according to claim 4. 6. A thermal transfer ink ribbon, characterized in that the thermal transfer ink according to any one of claims 1 to 5 is formed as a hot-melt ink layer on a substrate.