JP2989836B2 - Thermal transfer recording medium - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium, and more specifically, a thermal transfer recording medium capable of forming a printed image excellent in both print quality and abrasion resistance. Regarding the medium.

[PRIOR ART AND PROBLEMS TO BE SOLVED] For example, in the field of barcode printers, word processors, facsimile machines, etc., thermal transfer recording media capable of relatively easily obtaining clear printed images are widely used. .

The thermal transfer recording medium is required to be able to form a printed image having not only good print quality but also excellent scratch resistance.

That is, for example, in the case of a barcode, a print image portion (barcode) formed using a thermal transfer recording medium
Barcode reading is performed by pressing and moving the pen scanner for barcode reading, so accurate reading is not possible if the printed image area is rubbed during transportation of the product and the barcode is faded or disappears become. Further, when reading is repeatedly performed by the pen scanner, the barcode may be scraped by the pen scanner.

Furthermore, for example, even if a printed image is formed on a cardboard box or the like, if the cardboard box rubs against the floor surface or another cardboard box or the like,
There is a problem that the printed image is blurred or disappears.

By the way, as a means for improving the scratch resistance of a printed image formed using a thermal transfer recording medium, a heat-softening color material layer (ink layer) which is transferred onto a medium to be transferred in a molten state and then solidified again is used. It is conceivable to increase the mechanical strength.

However, when the mechanical strength of the heat-softening color material layer is increased, a problem arises in that the scratch resistance is improved but the print quality is reduced.

 The present invention has been made based on the above circumstances.

That is, an object of the present invention is to provide a heat-sensitive transfer recording medium capable of forming a printed image excellent in both print quality and scratch resistance.

[Means for Solving the Problems] In order to solve the problems, as a result of intensive studies by the present inventors, a heat-softening color material layer is provided via a specific intermediate layer adjacent to the support. The present inventors have found that a specific thermal transfer recording medium can form a printed image excellent in both print quality and abrasion resistance, and arrived at the present invention.

Configuration of the present invention comprises a support, which has a heat-softenable colorant layer through the intermediate layer adjacent to the support, the intermediate layer is a tensile strength of 1 kg / cm ² or more 100 kg / cm of less than ² A thermal transfer recording medium characterized by containing a thermoplastic rubber.

Hereinafter, the layer structure of the thermal transfer recording medium of the present invention,
The method will be described in detail by dividing into manufacturing methods and the like.

--Layer Configuration-- The thermal transfer recording medium of the present invention has a heat-softening color material layer on a support via an intermediate layer adjacent to the support.

—Support— The support in the thermal transfer recording medium of the present invention preferably has good heat resistance and high dimensional stability.

Examples of the material include papers such as plain paper, condenser paper, laminated paper, and coated paper; resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, and polyimide; composites of paper and resin film; and aluminum foil. Any of these metal sheets is suitably used.

The thickness of the support is usually 30 μm or less, preferably 2 to
It is in the range of 6 μm. If the thickness of the support is 30 μm or less, particularly good printing quality can be obtained.

In the thermal transfer recording medium of the present invention, the configuration on the back side of the support is arbitrary, and for example, a backing layer such as an anti-sticking layer may be provided.

On the support, an intermediate layer described in detail below is laminated adjacent thereto.

—Intermediate Layer— One of the important points in the present invention is that the intermediate layer adjacent to the support contains a thermoplastic rubber having a tensile strength of 1 kg / cm ² or more and less than 100 kg / cm ² .

In the present invention, the intermediate layer contains the specific thermoplastic rubber, the scratch resistance of the print image formed using the thermal transfer recording medium of the present invention does not cause a decrease in good print quality. Improvement can be achieved.

The intermediate layer having such a function or action contains at least the thermoplastic rubber and a heat-fusible substance.

The thermoplastic rubber has a tensile strength of 1 kg / cm ² or more and 100
less than kg / cm ^2, it is important that preferably less than 20 kg / cm ² or more 90 kg / cm ^2. The tensile strength of thermoplastic rubber is 1kg / cm
^If it is less than ² , the abrasion resistance may not be sufficiently improved. On the other hand, if it exceeds 100 kg / cm ² , the printing quality may be degraded.

Examples of the thermoplastic rubber include isoprene rubber (IR), high cis-butadiene rubber (BR), emulsion-polymerized styrene-butadiene rubber (E-BR), and solution-polymerized styrene-
Butadiene rubber (S-SBR), butyl rubber (IIR), ethylene-propylene-diene rubber (EPDM), chlorosulfonated polyethylene (CSM), methyl silicone rubber (M
Q), compounded rubber such as vinyl-methyl silicone rubber (VMQ), phenyl-methyl silicone rubber (PMQ), silicone rubber fluoride, vinylidene fluoride rubber, phosphazene rubber; SBS (styrene-butadiene- Linear (linear type) or radial (radial type) styrene, such as styrene), SIS (styrene-isoprene-styrene), S-EB-S [styrene-polyolefin (ethylene / butylene) -styrene] And thermoplastic elastomers such as thermoplastic elastomers, olefin thermoplastic elastomers, urethane thermoplastic elastomers, polyester thermoplastic elastomers, polyamide thermoplastic elastomers, and PVC thermoplastic elastomers.

Among these, preferred are SBS, S-I-
S, SEBS, SBR, polyester-based thermoplastic elastomer, and urethane-based thermoplastic elastomer.

The thermoplastic rubbers may be used alone or in combination of two or more.

The content of the thermoplastic rubber in the intermediate layer is 1% by weight.
Not less than 50% by weight, preferably not less than 2% by weight and not more than 20% by weight. When this content is less than 1% by weight,
When the intermediate layer contains the thermoplastic rubber, the effect of the present invention to be achieved by the intermediate layer may not be achieved. When the content is 50% by weight or less, transferability is good, and excellent printing quality can be obtained.

The intermediate layer contains the thermofusible substance together with the thermoplastic rubber.

When the intermediate layer contains the heat-fusible substance together with the thermoplastic rubber, it is possible to reduce cohesion and achieve good print quality.

Examples of the heat-fusible substance include carnauba wax,
Vegetable waxes such as wood wax, Ouriculi wax and Spar wax; animal waxes such as beeswax, insect wax, shellac wax and whale wax; And waxes such as mineral waxes such as montan wax, ozokerite and ceresin. In addition to these waxes, higher fatty acids such as palmitic acid, stearic acid, margaric acid and behenic acid can be mentioned. Higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol and eicosanol; cetyl palmitate, myricyl palmitate, cetyl stearate; And higher fatty acid esters such as myricyl stearate; amides such as acetamide, propionamide, palmitic amide, stearic amide and amide wax; and higher amines such as stearylamine, behenylamine and palmitylamine. Can be

These may be used alone or in combination of two or more.

Among these, preferred are waxes having a melting point in the range of 50 to 120 ° C. measured using Yanagimoto MJP-2.

When the heat-fusible substance is used, the content of the heat-fusible substance in the intermediate layer is usually 99% by weight or less, and preferably 50 to 99% by weight.

The intermediate layer, in addition to the thermoplastic rubber and the heat-fusible substance, for example, a thermoplastic resin, a surfactant, a filler,
It may contain other components such as a coloring material.

However, in order to sufficiently improve the scratch resistance, the intermediate layer preferably does not contain a coloring material.

The thermoplastic resin mainly has an action or function of improving the film holding property of the intermediate layer and suppressing cohesive failure in the intermediate layer.However, this may cause deterioration of print quality. Absent.

As the thermosoftening resin, for example, any of the same resins that can be contained in the thermosoftening color material layer described later can be suitably used.

When the thermoplastic resin is used, the content of the resin component in the intermediate layer is usually 20% by weight or less, and preferably 10% by weight or less.

The surfactant has an effect of controlling the releasability of the intermediate layer.

As the surfactant, various surfactants conventionally used for thermal transfer recording media can be used.

Specifically, for example, polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether,
Polyoxyethylene alkyl phenyl ether, polyoxyethylene sterol ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene Castor oil and hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, and the like.

These may be used alone or in combination of two or more.

When the surfactant is used, the content of the surfactant in the intermediate layer is usually 10% by weight or less.

The filler has an action or function of adjusting the peeling / transferring property to form a high-quality printed image.

Examples of the filler include silica, talc, calcium carbonate, alumina, acid clay, clay, magnesium carbonate, tin oxide, titanium white, graphite, thermosetting resin particles, fluororesin particles, melamine resin particles, urea resin particles, Benzoguanamine resin particles, acrylic resin particles,
Examples include styrene resin particles, boron nitride, copper, iron, aluminum, iron oxide, tin oxide, aluminum oxide, magnesium oxide, and titanium nitride.

The average particle size of the filler is usually 0.01 μm or more and 5 μm
Within the following range:

The coloring material has an effect of preventing the density of the obtained printed image from being reduced.

Therefore, when the intermediate layer contains the coloring material,
The color of the color material is preferably the same as the color of the color material in the heat-softening color material layer described in detail below.

As the coloring material, those similar to the coloring material in the thermosoftening coloring material layer described in detail below can be suitably used.

When the coloring material is used, the content of the coloring material in the intermediate layer is usually 10% by weight or less.

In the present invention, the intermediate layer containing the above components can be provided on the support by a coating method such as an aqueous coating method, a coating method using an organic solvent, or a hot melt coating method.

The thickness of the intermediate layer is usually in the range of 0.1 to 5.0 μm, preferably 0.3 to 1.5 μm in dry thickness. By setting this layer thickness within the above range, the object of the present invention can be sufficiently achieved.

On this intermediate layer, a thermosoftening colorant layer described in detail below is laminated directly or via another suitable intermediate layer.

-Thermo-softening color material layer-The thermo-softening color material layer usually contains a coloring material, a heat-fusible substance, and a thermoplastic resin.

Examples of the coloring material include pigments such as inorganic pigments and organic pigments, and dyes.

Examples of the inorganic pigment include titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide, iron oxide, and chromates of lead, zinc, barium, and calcium.

Examples of the organic pigment include azo-based, thioindigo-based, anthraquinone-based, anthranthrone-based, and triphenedioxazine-based pigments, vat dye pigments, phthalocyanine pigments such as copper phthalocyanine and its derivatives, and quinacridone pigments.

Examples of the organic dye include an acid dye, a direct dye, a disperse dye, an oil-soluble dye, and a metal-containing oil-soluble dye.

The content of the coloring material in the thermosoftening coloring material layer is usually
In the range of 5 to 35% by weight, preferably 10 to 25% by weight
Within the range.

As the heat-fusible substance, the same heat-fusible substance that can be used for the intermediate layer can be used.

The content of the heat-fusible substance in the heat-softening colorant layer is usually in the range of 10 to 95% by weight, preferably 60 to 95% by weight.
In the range of ~ 90% by weight.

Examples of the thermoplastic resin include polyester resin, ethylene resin, polyolefin resin, acrylic resin, vinyl chloride resin, styrene resin, rosin resin, petroleum resin, ionomer resin, rosin maleic resin, rosin Rosin derivatives such as phenolic resin and hydrogenated rosin and phenolic resin, terpene resin,
Cyclopentadiene resin and aromatic hydrocarbon resin are exemplified.

These may be used alone or in combination of two or more.

In the present invention, the softening point of the thermoplastic resin that can be suitably used is usually in the range of 60 to 150 ° C.

The content of the thermoplastic resin in the thermosoftening colorant layer is usually in the range of 2 to 30% by weight, preferably 5 to 30% by weight.
In the range of ~ 15% by weight.

The heat-softening colorant layer may contain a surfactant such as a polyoxyethylene chain-containing compound in addition to the above-mentioned components.

The heat-softening color material layer may further contain inorganic or organic fine particles (metal powder, silica gel, etc.) and oils (linseed oil, mineral oil, etc.).

The heat-softening color material layer can be coated on the heat-softening intermediate layer by using a coating method such as a water-based coating method or a coating method using an organic solvent.

The thickness of the heat-softening colorant layer is usually in the range of 1.0 to 8 μm, preferably in the range of 2.0 to 5.0 μm.

--- Manufacturing method--The thermal transfer recording medium of the present invention usually has the intermediate layer and the thermosoftening colorant applied in this order on the support, followed by a drying step and a surface smoothing if desired. It can be manufactured by cutting into a desired shape through a processing step or the like.

The thermal transfer recording medium thus obtained can be used in the form of a wide tape or a typewriter ribbon generally used for a line printer or the like.

Although the thermal transfer method using this thermal transfer recording medium is not different from the normal thermal transfer recording method, an example in which the most typical thermal head is used as a heat source will be described.

First, the heat-softening colorant layer of the thermal transfer recording medium is brought into close contact with the medium to be transferred, for example, plain paper. If necessary, a heat pulse is applied from the back side of the transfer paper by the platen, and the heat pulse is applied by the thermal head. Then, the intermediate layer and the heat-softening color material layer corresponding to a desired printing or transfer pattern are locally heated.

The temperature of the heated portion of the intermediate layer and the heat-softening color material layer rises, and the intermediate layer and the heat-softening color material layer are quickly softened and transferred onto the transfer medium.

[Examples] Next, examples of the present invention and comparative examples will be shown, and the present invention will be described more specifically.

In the following, the expression "part" means "part by weight". The tensile strength of the thermoplastic rubber used is ASTM D4
It is a value measured according to 12.

Example 1 The following intermediate layer composition was hot-melt coated on a 4.5 μm-thick polyethylene terephthalate film so as to have a dry thickness of 1.5 μm to form an intermediate layer in the thermal transfer recording medium of the present invention.

Intermediate layer composition Paraffin wax [melting point 75 ° C] ... 76 parts Fischer-Tropsch wax ... 20 parts [Softening point 108 ° C] Thermoplastic rubber (tensile strength 25 kg / cm ² ) 4 parts [Shell Chemical Co., Ltd. Clayton G1726X "] Then, the following heat-softening colorant layer composition was coated on the intermediate layer with a solvent using methyl ethyl ketone (MEK) as a solvent so as to have a dry thickness of 2.0 μm. A softening color material layer was formed to obtain a thermal transfer recording medium of the present invention.

Heat-softening colorant layer composition Carbon black 16 parts Ethylene copolymer 6 parts Acrylic resin 6 parts Styrene resin [softening point 82 ° C] 32 parts Phenol resin [softening point 85 ° C] ... 8 parts Rosin resin [softening point 75-81 ° C]… 32 parts The obtained thermal transfer recording medium is recorded (printed) on high quality paper (Beck smoothness 88 seconds) using a barcode printer.
Then, various characteristics of the printed image were evaluated.

 The results are shown in Table 1.

The printability of each printed image was evaluated as follows.

Print quality: PCS measurement was performed before and after the abrasion resistance test using a pen scanner [Photographic Science Co., Ltd., “Quick Check 111”].

 Note that PCS (%) was calculated by the following equation.

Generally, when the PCS value is 80% or more, it can be said that high print quality is obtained.

Scratch resistance: The printed image (bar code) formed on the high-quality paper was measured using a scratch resistance tester (variable load type, a prototype manufactured by Konica Corporation, based on JIS L0823) under the following conditions,
The following four grades were evaluated.

Setting conditions of the abrasion resistance tester Speed: about 40 reciprocations / min Load: 2 kg / cm ² reciprocations: 100 reciprocations Friction element surface area: 2 cm ² Evaluation ：: No stain is seen on the printed image.

 Δ: Stain is slightly observed in the printed image.

 X: The stain on the printed image is apparent.

Scratch resistance: A metal rod made of a sphere having a tip of 2 cm in diameter was attached using the tester described above, and the evaluation was performed under the same conditions as in the scratch resistance test.

(Example 2) Example 1 was the same as Example 1 except that the intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the thermal intermediate layer composition in Example 1. It carried out similarly.

 The results are shown in Table 1.

(Comparative Examples 1 to 3) The same procedure as in Example 1 was performed except that an intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the thermal intermediate layer composition in Example 1. A thermal transfer recording medium was prepared in the same manner as in Example 1, and a print image formed using the obtained thermal transfer recording medium was evaluated.

 The results are shown in Table 1.

(Evaluation) As is clear from Table 1, the print image formed using the thermal transfer recording medium of the present invention not only has improved print quality than the print image formed in the comparative example, It was confirmed that the scratch resistance and scratch resistance were significantly improved.

[Effects of the Invention] According to the present invention, since a heat-softening color material layer is provided via a specific intermediate layer adjacent to a support, excellent scratch resistance can be improved without causing a decrease in excellent print quality. An industrially useful heat-sensitive transfer recording medium having the advantage of being able to be achieved can be provided.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Nishizaki, Inventor Konica Co., Ltd., 1 Sakuracho, Hino-shi, Tokyo (56) References JP-A-63-288780 (JP, A) JP-A-62-30083 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41M 5/38

Claims (1)

(57) [Claims] 1. A heat-softening colorant layer is provided on a support via an intermediate layer adjacent to the support, and the intermediate layer has a tensile strength of 1 kg / cm ² or more and less than 100 kg / cm ² . A heat-sensitive transfer recording medium comprising a thermoplastic rubber.