JPH03126592A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To form a printing image excellent in both of printing quality and scratch resistance by providing a heat-softenable colorant layer on a support through the intermediate layer adjacent to the support and incorporating thermoplastic rubber having specific tensile strength in the intermediate layer. CONSTITUTION:A heat-softenable colorant layer is provided on a support through the intermediate layer adjacent to the support and the intermediate layer contains thermoplastic rubber having tensile strength of 1-below 100kg/cm<2>. The intermediate layer contains at least the thermoplastic rubber and a heat- meltable substance. As the thermoplastic rubber, for example, a styrene/ butadiene/styrene thermoplastic elastomer, a styrene/isoprene/styrene thermoplastic elastomer, a styrene/polyolefin(ethylene butylene)/styrene polyester type thermoplastic elastomer and an urethane type thermoplastic elastomer are designated and the content thereof is 99wt.% or less. The heat-softenable colorant layer contains a colorant, a heat-meltable substance and a thermoplastic resin.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer recording medium, and more specifically, to a thermal transfer recording medium that can form printed images with excellent print quality and scratch resistance. Regarding recording media.

[Prior Art and Problems to be Solved by the Invention] For example, in the fields of barcode printers, word processors, facsimiles, etc., thermal transfer recording media are widely used because they can relatively easily obtain clear printed images. .

This thermal transfer recording medium is required not only to have good print quality but also to be able to form printed images with excellent scratch resistance.

That is, for example, in the case of barcodes, the barcode is read by moving a barcode reading pen scanner while pressing it against a printed image area (barcode) formed using a thermal transfer recording medium. For example, if the printed image area of a product is rubbed during transportation and the barcode is faded or erased, accurate reading becomes impossible. Additionally, if the barcode is read by the pen scanner in reverse, the barcode may be scraped off by the pen scanner.

Furthermore, even if a printed image is formed on a cardboard box, for example, if the cardboard box rubs against the floor or other cardboard boxes, the printed image may fade or disappear.

By the way, as a means to improve the scratch resistance of a printed image formed using a thermal transfer recording medium, a heat-softening coloring material layer (which is transferred to a transfer medium in a molten state and then solidified again) is used.
One possibility is to increase the mechanical strength of the ink layer.

However, increasing the mechanical strength of the heat-softening color material layer causes a problem in that although the scratch resistance improves, the print quality deteriorates.

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

That is, an object of the present invention is to provide a thermal transfer recording medium that can form a printed image that is excellent in both print quality and scratch resistance.

[Means for Solving the Problems] In order to solve the above-mentioned problems, as a result of extensive research, the present inventors have discovered that a heat-softening coloring material layer is formed through a specific intermediate layer adjacent to a support. It was discovered that the specific heat-sensitive transfer recording medium provided can form a printed image excellent in both print quality and scratch resistance, and the unprinted tJ1 was achieved.

The structure of the present invention has a heat-softening coloring material layer on a support via an intermediate layer adjacent to the support, and the intermediate layer has a tensile strength of 1 kg/ca+2 or more'': 100
The present invention is a thermal transfer recording medium characterized in that it contains a thermoplastic rubber of less than kg/cm2.

Below, the thermal transfer recording medium of the present invention will be described in detail in terms of layer structure, manufacturing method, etc.

- Single Layer Structure 11 The thermal transfer recording medium of the present invention has a heat-softening coloring material layer on a support via an intermediate layer adjacent to the support.

It is desirable that the support in the thermal transfer recording medium of the present invention has good heat resistance strength and high dimensional stability.

The materials include, for example, papers such as paperback paper, condenser paper, laminated paper, and coated paper; resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, and polyimide; composites of paper and resin films, and aluminum. Any metal sheet such as foil is preferably used.

The thickness of the support is usually 30 μm or less, preferably 2 to 2 μm.
It is within the range of 6pm. Particularly good printing quality can be obtained if the thickness of the support is 30 pm or less.

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

An intermediate layer, which will be described in detail below, is laminated adjacent to the support.

One of the important points in the present invention is whether the intermediate layer adjacent to the support has a tensile strength of 1 kg/cm' or more and 100 kg.
/cm2.

In the present invention, since the intermediate layer contains the above-mentioned specific thermoplastic rubber, the scratch resistance of the printed image formed using the heat-sensitive transfer recording medium of the present invention is maintained without deteriorating the good print quality. Trying to improve becomes a good thing.

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

The thermoplastic rubber has a tensile strength of 1 kg/cm2.
100 kg/cs” or more, preferably 20 kg/cs”
It is important that the tensile strength of the thermoplastic rubber is at least 1 kg/cm2 and less than 90 kg/c2. If the tensile strength of the thermoplastic rubber is less than 1 kg/c+s2, the improvement in abrasion resistance may not be sufficient.

- If the force exceeds 100 kg/cgr, printing quality may deteriorate.

Examples of the thermoplastic rubber include isoprene rubber (
IR), high cis-tutadiene rubber (BR), emulsion polymerized styrene-butadiene rubber (E-BR), solution polymerized styrene-phtadiene rubber (S-3BR), tutadiene rubber (II)
R), ethylene-propylene-diene rubber (EPDM)
, chlorosulfonated polyethylene (C3M), methyl silicone rubber (MQ), vinyl-methyl silicone rubber (VMQ), phenyl-methyl silicone rubber (PMQ)
), silicone rubber, vinylidene rubber,
Compounded rubber such as phosphazene rubber; 5-B-3 (styrene-butadiene-styrene), S-1-5 (styrene-isoprene-styrene), 5-EB-3 [styrene-
Linear type or radial type styrene thermoplastic elastomer such as polyolefin (ethylene/butylene) - styrene], olefin thermoplastic elastomer, urethane thermoplastic elastomer, polyester thermoplastic elastomer, polyamide PVC thermoplastic elastomer,
Examples include thermoplastic elastomers such as.

Among these, preferred is 5-B-3,5-I-3
, 5-E-B-3, SBR, polyester thermoplastic elastomer, and urethane thermoplastic elastomer.

Furthermore, 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.
More than 50% and less than 50%, preferably 111% double
More than 20 weights! , "C% or less. If this content is less than 1% by weight, the effect of the present invention that should be achieved by containing thermoplastic rubber in the intermediate layer may not be achieved. 50% by weight h1% If it is below, the transferability is good.
It is possible to obtain excellent print quality.

The intermediate layer contains the thermoplastic rubber and the thermofusible substance.

By containing the thermofusible substance in the intermediate layer together with the thermoplastic rubber, it is possible to reduce the cohesive force and achieve good print quality.

Examples of the thermofusible substance include vegetable waxes such as carnauba wax, wood wax, auriculie wax, and nispar wax; Animal waxes such as M wax, insect wax, shellac wax and spermaceti wax; petroleum waxes such as paraffin wax, microcrystalline wax, Fischer Tropish wax, polyethylene wax, ester wax and acid wax; and montan wax, osichelite and shellac. This includes waxes such as mineral waxes, and in addition to these waxes, higher fatty acids such as palmitic acid, stearic acid, margaric acid, and behenic acid; valmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol , higher alcohols such as myricyl alcohol and eicosanol; higher fatty acid esters such as cetyl valmitate, myricyl valmitate, cetyl stearate and myricyl stearate; acetamide, propionic acid amide, palmitic acid amide, stearic acid amide and amide wax and higher amines such as stearylamine, behenylamine, and valmitylamine.

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

Among these, preferred is a wax whose melting point is within the range of 50 to 120°C, as determined by a14 using Yanagiki MJP-2 type.

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

In addition to the thermoplastic rubber and the heat-melting substance, the intermediate layer may contain other components such as a thermoplastic resin, a surfactant, a filler, and a coloring material.

However, in order to sufficiently improve the JtA resistance, it is preferable that the intermediate layer does not contain a coloring material.

Does the thermoplastic resin mainly have the function of improving the film retention of the intermediate layer and suppressing cohesive failure within the intermediate layer? Does this cause deterioration of printing quality? do not have.

As the heat-softening resin, any of the same resins that can be contained in the heat-softening coloring material layer described later can be suitably used.

When the 8I'IT plastic resin is used, the content of the resin component in the intermediate layer is usually 20% by weight or less, preferably 10% by weight or less.

The surfactant has the effect of adjusting the releasability of the intermediate layer.

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

Specifically, for example, polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene sterol ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene block Examples include volima, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil and hardened mustard oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, 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 the function of controlling peeling and transferability 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, fluorine resin particles, melamine resin particles, and urea resin particles. , benzoguanamine resin particles, acrylic resin particles, styrene resin particles, boron nitride, copper, iron, aluminum iron oxide, tin oxide, aluminum oxide, magnesium oxide, titanium nitride, and the like.

The average particle size of the filler is usually in the range of 0.01 g m or more and 5 pm or less.

The coloring material has the function of preventing the density of the obtained printed image from decreasing.

Therefore, when the intermediate layer contains the coloring material, it is preferable that the color of the coloring material is the same as the color of the coloring material in the heat-softening coloring material layer, which will be described in detail below.

As the coloring material, the same coloring material as the coloring material in the heat-softening coloring material layer described in detail below can be suitably used.

When using the coloring material, the content of the coloring material in the intermediate layer is usually 111% or less.

In the present invention, the intermediate layer containing the above components can be coated on the support by a coating method such as a water-based 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 pm, preferably in the range of 0.3 to 1.5 gm in terms of dry explosion thickness. By setting this layer thickness within the above range, 1
It is possible to fully achieve the purpose of the unreleased project.

On this intermediate layer, a heat-softening coloring material layer, which will be described in detail below, is laminated directly or via another suitable intermediate layer.

-Thermosoftening Coloring Material Layer- The thermosoftening coloring material layer usually contains a coloring material, a heat-melting substance, and a thermoplastic resin.

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

The inorganic pigments include 1, titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide,
These include iron oxides and chromates of lead, zinc, barium and calcium.

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

The organic dyes include acid dyes and direct dyes.

Examples include disperse dyes, oil-soluble dyes, and metal-containing oil-soluble dyes.

The content of the coloring material in the heat-softening coloring material layer is as follows.

Usually within the range of 5 to 35% by weight, preferably 10% by weight.
~25% by weight.

1i11 As the heat-fusible substance, the same heat-fusible substance as can be used for the intermediate layer can be used.

The content of the heat-melting substance in the heat-softening coloring material layer is 1
Usually within the range of 10 to 95% by weight, preferably 6% by weight.
It is within the range of 0 to 90% by weight.

Examples of the thermoplastic resin include polyester resin, ethylene resin, polyolefin citrus resin, acrylic resin, vinyl chloride resin, styrene resin, rosin resin, petroleum resin, ionomer resin, rosin maleic resin, Examples include rosin derivatives such as rosin phenol resin and hydrogenated rosin, phenol resins, terpene resins, cyclopentadiene resins, and aromatic hydrocarbon resins.

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 coloring material layer is 1
Usually within the range of 2 to 30% by weight, preferably 5 to 30% by weight.
It is within the range of 15% by weight.

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

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

The heat-softening color material layer can be coated using a water-based coating method or an organic solvent, for example! It is possible to apply the coating method on the heat-softening intermediate layer by employing a coating method such as method No. 11.

The layer thickness of this heat-softening coloring material layer is usually in the range of 0 to 8 gm, preferably 2.0 to 5 gm. [It is within the range of lm.

11. Manufacturing method, etc. 11. The thermal transfer recording medium of the present invention is usually provided with:
11. It can be manufactured by coating the 'I layer and the heat-softening coloring material in this order, and then optionally performing a drying step, a surface smoothing treatment step, etc., and then cutting into a desired shape.

The thermal transfer recording medium obtained in this way is as follows.

It can be used in the form of a wide tape generally used in line printers, or a typewriter ribbon.

The heat-sensitive transfer method using this heat-sensitive transfer recording medium is not different from the usual heat-sensitive transfer recording method, and will be explained by taking as an example the case where the most typical thermal head is used as the heat source.

First, the heat-softening coloring material layer of the heat-sensitive transfer recording medium and the transfer medium, for example, plain paper, are brought into close contact with each other, and if necessary, a heat pulse is further applied from the back side of the transfer paper using a platen.
A heat pulse is applied by a thermal head to locally heat the intermediate layer and the heat-softening coloring material layer corresponding to the desired printing or transfer pattern.

The temperature of the heated portions of the intermediate layer and the heat-softening coloring material layer increases, and the middle layer and heat-softening coloring material layer are quickly softened and transferred onto the transfer medium.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

In addition, in the following, the expression "part" is [weight? Represents BJ.

(Example 1) The following intermediate layer composition was hot-melt coated on a polyethylene terephthalate film having a thickness of 4.54 m to a dry thickness of 1.51 Lm to form an intermediate layer in a thermal transfer recording medium of the present invention. .

East side" u [Hiro] Paraffin wax [melting point 75°C]...76 parts Feuscher-Tropsch wax...20 parts [softening point 108°C] Thermoplastic rubber (tensile strength 25 kg/c+m2) ...
・4 parts [manufactured by Shell Chemical Co., Ltd., [Krayton G1726X,
] Next, on this intermediate layer, the following heat-softening coloring material layer composition was applied to a dry thickness of 2.0 μm using a solvent such as methyl ethyl ketone (MEK). A heat-softening coloring material layer was formed, and a heat-sensitive transfer recording medium of 11 fl undeveloped was obtained.

f9 ゛ hi a Carbon black・・・・・・・・・・・・・・・・・・
16-functional styrene copolymer 6 acrylic resin 6 styrene resin [softening point 82°C] ...32 Phenol resin [softening point 85°C] ...80 Thin resin [softening point 75-81°C] ...32 Using the obtained thermal transfer recording medium without a barcode printer The images were recorded (printed) on high-quality paper (Peck 11 smoothness: 88 seconds), and various properties of the printed images were evaluated.

The results are shown in Table 1.

The various properties of the printed images were evaluated as follows.

Print quality: #Pc5IIn was determined before and after the abrasion test using a Venscanner (manufactured by Photographic Science Co., Ltd., [Quick Check Ill J]).

In addition, pcs (%) is calculated by the following formula: Calculated.

=pcs <%) Also, in general, this PC3 value If it is 80% or higher, the print quality is high. It can be said that

Scratch resistance: The printed image (barcode) formed on high-quality paper was measured using a scratch resistance tester (variable load type, prototype manufactured by Konica, compliant with JISL 823) under the following conditions. It was evaluated in four stages.

Electric 1″″IA Speed: Approximately 40 round trips/min Load: 2 kg/cm” Round trip @: 100 round trips Thick surface area: 20■2 ■ ○: There is no dirt or stains visible on the printed image. Not possible.

Δ: There is some dirt on the printed image. It will be done.

×: It is obvious that the printed image is dirty. be.

Scratch resistance: Using the above testing machine, a spherical metal rod with a diameter of 2 cm was attached to the tip, and evaluation was conducted under the same conditions as in the scratch resistance test.

(Example 2) The same procedure as in Example 1 was used, except that in place of the thermal intermediate layer composition in Example 1, an intermediate layer composition having the blending ratio shown in Table 2 was used. It was carried out in the same manner.

The results are shown in Table 1.

(Comparative Examples 1 to 3) In Example 1, the intermediate layer composition having the blending 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 printed image formed using the obtained thermal transfer recording medium was evaluated.

The results are shown in Table 1.

No. 1 table No. table *l-The numerical value is too low to determine the exact value.

*1. Manufactured by Shell Chemical Co., Ltd. [Crayton GI726XJ
(Bow single eye strength 25Kg/cm2) *2 Shell Chemical Co., Ltd., [Clayton DI300
1. , tensile strength IKg/cm2 or less) *4: Shell I b
'PLliJ, 'Clayton G1 [i50 J
(Tensile strength: 352 Kg/cm2) (Evaluation) As is clear from Table 1, the print quality of the print image formed using the thermal transfer recording medium of the present invention is improved compared to the print image formed using the comparative example. It was confirmed that not only was it effective, but also the scratch resistance and scratch resistance were significantly improved.

[Effects of the Invention] According to the present invention, since a heat-softening coloring material layer is provided through a specific intermediate layer adjacent to the support, the scratch resistance can be improved without deteriorating the excellent print quality. It is possible to aim for
It is possible to provide an industrially useful thermal transfer recording medium having the following advantages.

-60(

Claims (1)

[Claims] (1) A heat-softening coloring material layer is provided on the 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 thermal transfer recording medium characterized by containing a certain thermoplastic rubber.