JPH0999643A - Thermal transfer recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer recording material good in the transfer properties of an ink layer, good in the close adhesiveness of ink to various plastic film and capable of forming a printing image excellent in scratch resistance. SOLUTION: In a thermal transfer recording material wherein at least a hot-melt ink layer consisting of a hot-melt material and a color former is provided on a base material, 30-90wt.% of an epoxy resin and 10-70wt.% of an acrylic resin with a number average mol.wt. is 30000-300000 are added to the hot-melt material.

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 material for forming an image having excellent fastness on various image receivers.

[0002]

2. Description of the Related Art Conventional thermal transfer recording materials are generally applied to a base material coated with a hot-melt ink containing a wax as a main component of a vehicle or a paper having a poor surface smoothness. In order to form an image with good quality, or to form an image with good scratch resistance,
It is a hot-melt ink containing a resin as a main component of a vehicle.

In recent years, a thermal transfer recording material is used for printing a bar code or the like which is used for parts management in a manufacturing process in a manufacturing factory, product management, product management in the distribution field, article management in the field of use, and the like. Bar code printers and label printers are being used. In the case of a bar code used in the field of distribution and the like, there are many occasions of rubbing, so that particularly good scratch resistance is required.

In addition to bar codes, in commercial printing fields, outdoor advertisements, election posters, general posters, standing signs,
Stickers, catalogs, brochures, calendars, etc.
In the packaging field, for light packaging bags, labels for containers such as foods, beverages, chemicals, paints, binding tapes, etc.In the field of clothing, for quality indication labels, process control labels, product control labels, etc. Thermal transfer printers have come to be used, and these are also required to have scratch resistance.

Also, as the image receptor, a dedicated image receptor such as a polyethylene terephthalate film having a special surface treatment has been used as an image receptor for a bar code by thermal transfer, but recently, a general polyethylene terephthalate film or a chloride is used. Plastic films such as vinyl-based resin films that have not been surface-treated have also been used and are becoming more diverse. More recently,
Cutting plotters have begun to spread, and the number of cases in which an image is formed on a vinyl chloride resin film by thermal transfer is increasing.

However, in the case of a conventional thermal transfer recording material using a heat-meltable ink containing a wax as a main vehicle, the transferability (breakage of the ink layer) is good,
The obtained printed image was inferior in scratch resistance. Further, in the case of a thermal transfer recording material using a heat-meltable ink mainly composed of a resin such as ethylene-vinyl acetate copolymer, the scratch resistance of the obtained image is relatively good, but the melt viscosity is high. The transferability was inferior to the wax-based one. Moreover, in both of these conventional examples, there was a problem that the adhesion of the printed image to a general plastic film was poor, and as a result, the scratch resistance was poor.

In view of the above points, an object of the present invention is to form an image having excellent transferability (danger of the ink layer), good adhesion to various plastic films, and excellent scratch resistance. Another object of the present invention is to provide a heat transfer recording material.

[0008]

The present invention provides (1) a thermal transfer recording material comprising a base material and a heat-meltable ink layer comprising at least a heat-meltable material and a coloring agent.
The thermal transfer recording material is characterized in that the heat fusible material contains 30 to 90% by weight of an epoxy resin and 10 to 70% by weight of an acrylic resin having a number average molecular weight of 30,000 to 300,000.

The present invention further comprises (2) the epoxy resin selected from the group consisting of tetraphenolethane tetraglycidyl ether, cresol novolac polyglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.
The present invention relates to the thermal transfer recording material described in the above item (1), wherein the thermal transfer recording material is one kind or two or more kinds.

The present invention further comprises (3) one or more selected from the group consisting of tetraphenolethane tetraglycidyl ether, cresol novolac polyglycidyl ether and bisphenol F diglycidyl ether. The invention relates to the thermal transfer recording material as described in (1) above.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-meltable ink layer of the present invention comprises at least a heat-meltable material and a colorant, and 30 to 90% by weight, preferably 40 to 40% by weight of an epoxy resin is contained in the heat-meltable material. 60% by weight, number average molecular weight 30,000 to 30
It contains 10 to 70% by weight, preferably 40 to 60% by weight of 0000 acrylic resin.

By using the epoxy resin and the high molecular weight acrylic resin together in a specific ratio in this manner, the transferability (breakage) of the ink layer is higher than that of the conventional resin type ink layer.
And the adhesion to various plastic films is improved, and accordingly, an image having excellent scratch resistance and the like can be obtained. That is, the epoxy resin mainly improves the sharpness of the ink layer and improves the transferability. Further, a high molecular weight acrylic resin has good adhesion to various plastic films and, due to its robust and strong properties, improves scratch resistance when transferred to a plastic film. Furthermore, it has high transparency and is suitable for color printing. More specifically, the high molecular weight acrylic resin specified in the present invention gives an image having good scratch resistance, but tends to deteriorate the sharpness of the ink layer. However, by using the high molecular weight acrylic resin and the epoxy resin together, it is possible to obtain an image having good scratch resistance while ensuring good scratching of the ink layer.

When the proportion of the epoxy resin is less than the above range and the proportion of the acrylic resin is more than the above range, the epoxy resin having good transferability is few and the adhesion of the ink to the substrate becomes excessive, Transferability is reduced. On the other hand, when the proportion of the epoxy resin is higher than the above range or the proportion of the acrylic resin is lower than the above range, the strength of the ink is lowered when transferred to various plastic films, and the scratch resistance is not improved.

The epoxy resin used in the present invention is not particularly limited, and any ordinary epoxy resin can be used. In consideration of the dispersibility of the colorant, the transferability of the ink, etc., tetraphenolethanetetraglycidyl is used. Ether, cresol novolac polyglycidyl ether,
An epoxy resin containing 50% (wt%, the same below) or more, and more preferably 70% or more of one or more selected from the group consisting of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether is preferable. The epoxy resin used in the present invention means an uncured (uncrosslinked) epoxy resin.

In the present invention, it is particularly preferable that the total amount of the epoxy resin is composed of the specific epoxy resin, but it is not always necessary, and the epoxy resin containing 50%, particularly 70% or more of the specific epoxy resin is not necessarily required. If so, the desired effect is achieved. If the content of the specific epoxy resin in all the epoxy resins is less than the above range, the dispersibility of the pigment is deteriorated and the transferability is deteriorated.

The above-mentioned tetraphenol ethane tetraglycidyl ether (hereinafter sometimes abbreviated as TPETGE) is one of the polyfunctional epoxy resins represented by the formula (I) and has a softening point in the range of 92 ° C.

[0017]

Embedded image

The cresol novolac polyglycidyl ether (hereinafter, sometimes abbreviated as CNPGE) is a kind of polyfunctional epoxy resin, and in the present invention, it has the formula (II):

[0019]

Embedded image

Those represented by (in the formula, m is usually an integer of 3 to 7) are preferred. The CNPGE used in the present invention also includes a mixture having different values of m. As CNPGE, those having a softening point in the range of 60 to 120 ° C. are preferable.

The above-mentioned bisphenol A diglycidyl ether (hereinafter sometimes abbreviated as BPADGE) is a kind of bifunctional epoxy resin, and in the present invention, it has the formula (II).
I):

[0022]

Embedded image

(In the formula, n is usually an integer of 0 to 13)
Those represented by are preferred. BPA used in the present invention
DGE also includes mixtures of different values of n.
As BPADGE, those having a softening temperature in the range of 60 to 140 ° C are preferable.

The above-mentioned bisphenol F diglycidyl ether (hereinafter sometimes abbreviated as BPFDGE) is a kind of bifunctional epoxy resin, and in the present invention, it has the formula (I
V):

[0025]

Embedded image

A compound represented by the formula (in the formula, p is usually an integer of about 0 to 33) is preferable. BP used in the present invention
FDGE also includes a mixture of two or more different p values in formula (IV). 60 ~ for BPFFDGE
Those having a softening point in the range of 140 ° C. are preferable.

Examples of other epoxy resins which can be used in combination with the above specific epoxy resin in the present invention include the following.

(1) Glycidyl ether type brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, glycerin triglycidyl ether, pentaerythritol diglycidyl ether, naphthol modified cresol novolac polyglycidyl Examples include ether.

(2) Glycidyl ether / ester type p-oxybenzoic acid glycidyl ether / ester and the like.

(3) Glycidyl ester type phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, dimer acid diglycidyl ester and the like.

(4) Glycidyl amine type glycidyl aniline, triglycidyl isocyanurate, tetraglycidyl diaminodiphenylmethane and the like can be mentioned.

(5) Linear aliphatic epoxy type Examples include epoxidized polybutadiene and epoxidized soybean oil.

(6) Alicyclic epoxy type 3,4-epoxy-6-methylcyclohexylmethyl
3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl
Examples include 3,4-epoxycyclohexanecarboxylate.

The other epoxy resins may be used alone or in combination of two or more. As the other epoxy resin, those having a softening temperature of 60 ° C. or higher are preferable, but the softening temperature of the entire heat-melting material is 60 ° C. when mixed with other epoxy resin, the above specific epoxy resin or acrylic resin
Liquid epoxy resins can also be used as long as they are as described above.

The acrylic resin used in the present invention has a number average molecular weight of 30,000 to 300,000. Among them, those having a number average molecular weight of 30,000 to 150,000, particularly 40,000 to 150,000 are preferably used. When the number average molecular weight of the acrylic resin is less than the above range,
Sufficient scratch resistance cannot be obtained, and on the other hand, when it is larger than the above range, the transferability tends to deteriorate. The acrylic resin preferably has a glass transition point of 30 to 120 ° C.

Examples of the acrylic resin include (meth) acrylic acid and (meth) acrylic acid alkyl ester (as the alkyl group, for example, methyl, ethyl, propyl, isopropyl, butyl, amyl, octyl, stearyl, etc., having 1 carbon atom). ~ 25 are included),
Homopolymers and copolymers of acrylic monomers such as (meth) acrylonitrile, and one or more of the above acrylic monomers and one or more other copolymerizable therewith Examples thereof include copolymers with monomers such as styrene, butadiene, siloxane bond-containing vinyl monomers, and fluorine-containing vinyl monomers. In particular,
Acrylic acid resin, methacrylic acid resin, acrylic acid alkyl ester resin, methacrylic acid alkyl ester resin,
Examples thereof include acrylonitrile resin, acrylonitrile-styrene copolymer resin, and acrylonitrile-styrene-butadiene copolymer resin.

The heat-meltable material of the present invention may be blended with a heat-meltable resin other than those mentioned above within the range not impairing the object of the present invention. Examples of such heat-meltable resin include ethylene-vinyl acetate copolymer resin and vinyl chloride-
Examples thereof include vinyl acetate copolymer resin, phenol resin, polyester resin and polyamide resin. When the other heat-melting resin is used, the total amount of the heat-melting material is 30
% Or less, preferably 15% or less, and more preferably 5% or less.

The heat melting material as a whole has a softening temperature of 60 to 12 from the viewpoint of storage stability and transferability of the heat transfer recording material.
The range of 0 ° C is preferred.

The content of the heat-meltable material in the heat-meltable ink layer is preferably in the range of about 40 to 95% from the viewpoint of transferability and the like.

The colorant used in the present invention includes carbon black, azo pigments (insoluble azo, azo lake, condensed azo pigment), phthalocyanine pigments, nitro pigments, nitroso pigments, anthraquinone pigments, nigrosine pigments. , Quinacridone pigments, perylene pigments, isoindolinone pigments, dioxazine pigments, titanium white, calcium carbonate, various organics such as barium sulfate,
Inorganic pigments can be used. These pigments may be used in combination with a dye. The content of the colorant in the ink layer is 5 to 60.
A range of% is appropriate.

When a subtractive color mixture is used to form a multicolored or full-color image, yellow, magenta, and cyan pigments, and if necessary, black pigments are used.

Transparent pigments are preferably used as the yellow, magenta and cyan pigments. An opaque black pigment is usually used.

Examples of the yellow transparent pigment include naphthol yellow S, Hansa yellow 5G, Hansa yellow 3G, Hansa yellow G, Hansa yellow GR, Hansa yellow A, Hansa yellow RN, Hansa yellow R, benzidine yellow, benzidine yellow G, benzidine yellow GR,
One or more organic pigments such as permanent yellow NCG and quinoline yellow lake can be used.

Examples of magenta transparent pigments include Permanent Red 4R, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Carmine FB, Resole Red, and Permanent Red F5.
One or more organic pigments such as R, Brilliant Carmine 6B, Pigment Scarlet 3B, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, and Quinacridone Red can be used.

As the transparent cyan pigment, for example, one or more organic pigments such as Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue and fast sky blue can be used.

Here, the transparent pigment means a pigment which gives a transparently colored ink when dispersed in a transparent vehicle.

As the black pigment, for example, one or more kinds of inorganic pigments such as carbon black having an insulating property and conductivity and organic pigments such as aniline black can be used.

The content of the colorant in each colored ink layer is usually about 5 to 60%.

When bisphenol A diglycidyl ether is used as the epoxy resin, it is preferable to use a pigment such as carbon black having an oil absorption of 80 or more. Although bisphenol A diglycidyl ether does not necessarily have good dispersibility of pigments such as carbon black, when a pigment having an oil absorption of 80 or more is used, the hot-melt ink in which the pigment dispersibility is good and the pigments are uniformly dispersed is obtained. As a result, transferability becomes good. Here, the oil absorption of the pigment means the oil absorption (ml) of dibutyl phthalate per 100 g of the pigment.

Among the above epoxy resins, tetraphenol ethane tetraglycidyl ether, cresol novolac polyglycidyl ether and bisphenol F diglycidyl ether, especially tetraphenol ethane tetraglycidyl ether and cresol novolac polyglycidyl ether have a low oil absorption of the pigment. And the dispersibility is good.

In the heat-fusible ink layer of the present invention, a dispersant and the like can be appropriately blended in addition to the above components.

In the heat-fusible ink layer of the present invention, an epoxy resin and an acrylic resin are dissolved in a solvent which dissolves them or a solvent which does not dissolve them (including water), and further pigments and other additives are added. Can be formed by dissolving and dispersing to prepare a coating liquid, coating the coating liquid on a substrate, and drying.

The coating amount of the heat-meltable ink layer in the present invention (in terms of solid content, the same applies hereinafter) is usually 0.02 to 5 g / m.
² , more preferably 0.5 to 3 g / m ² .

Examples of the base material include polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, polyethylene naphthalate film, polybutylene naphthalate film and polyarylate film, polycarbonate film, polyamide film, aramid film, polyether sulfone film. , Polysulfone film, polyphenylene sulfide film, polyetheretherketone film, polyetherimide film, modified polyphenylene ether film, polyacetal film, and other various plastic films that are commonly used as a base film for ink ribbons of this type are used. it can. Also, high-density thin paper such as condenser paper can be used. The thickness of the substrate is usually about 1 to 10 μm, and from the viewpoint that the heat diffusion can be reduced and the resolution can be increased,
A range of 6 μm is preferred.

When the thermal transfer recording material of the present invention is used in a thermal transfer printer equipped with a thermal head, a silicone resin, a fluororesin, a nitrocellulose resin, or a resin thereof is formed on the back surface of the substrate (the surface which is in sliding contact with the thermal head). It is necessary to provide a conventionally known stick-preventing layer made of various heat-resistant resins modified by, for example, silicone-modified urethane resin, silicone-modified acrylic resin, or a mixture of these heat-resistant resins with a lubricant. preferable.

The thermal transfer recording material of the present invention includes a thermal transfer recording material for forming a single color image and a color thermal transfer recording material for forming a multicolor or full color image by using subtractive color mixture. Be done.

A thermal transfer recording material for forming a monochromatic image is a monochromatic thermofusible ink layer provided on a substrate. The colors of the heat-meltable ink layer are black, red, blue,
Examples include green, yellow, magenta, and cyan.

One embodiment of a color thermal transfer recording material for forming a multicolor or full color image is
A yellow heat-meltable ink layer, a magenta heat-meltable ink layer, a cyan heat-meltable ink layer, and if necessary, a black heat-meltable ink layer are arranged side by side on a single substrate. . There are various modes for arranging the ink layers of the respective colors, which are appropriately selected according to the type of the printer.

FIG. 1 is a partial plan view showing an example of the thermal transfer recording material of the above embodiment. In FIG. 1, a yellow heat-meltable ink layer 2Y, a magenta heat-meltable ink layer 2M, and a cyan heat-meltable ink layer 2C are arranged side by side on a single substrate 1. The ink layers 2Y, 2M, and 2C each have a fixed size, and are arranged in the longitudinal direction of the base material 1 repeatedly in the fixed order as one repeating unit U. The order in which the three color ink layers are arranged in the repeating unit U is appropriately determined according to the transfer order of each color. A black ink layer may be added to the repeating unit U.

Another embodiment of a color thermal transfer recording material for forming a multicolor or full color image is 1
First, a yellow heat-meltable ink layer is provided on one substrate
Thermal transfer recording material, a second thermal transfer recording material having a magenta heat fusible ink layer provided on another substrate, and a third thermal transfer recording material having a cyan heat fusible ink layer provided on another substrate. It comprises a recording material and, if desired, a fourth set of thermal transfer recording materials with a black heat-meltable ink layer provided on another substrate.

When the thermal transfer recording material for color image formation is used, a multicolor or full color image having excellent scratch resistance can be obtained. Furthermore, since the heat-meltable ink layers of the respective colors in the present invention have good overlayability, a color image with good color reproducibility can be obtained.

In order to form a printed image using the thermal transfer recording material of the present invention, the ink layer of the thermal transfer recording material is superposed on the material to be transferred, and thermal energy is applied imagewise to the ink layer. A thermal head is generally used as a heat source for giving heat energy, but any known one such as a laser beam, an infrared flash, or a heat pen can be used.

In the case where the transfer target has a three-dimensional shape that is not a sheet, and the surface thereof is a curved surface, thermal transfer by laser light is advantageous because heat energy can be easily applied.

The formation of a multi-color or full-color image using the thermal transfer recording material for color image formation of the present invention is usually carried out by a thermal transfer printer in accordance with the separated color signals of the multi-color image, that is, the yellow signal, the magenta signal and the cyan signal. , Yellow ink dots, magenta ink dots, and cyan ink dots are sequentially transferred in a predetermined order to form a yellow separated image, a magenta separated image, and a cyan separated image on the image receptor. . The transfer order of yellow ink dots, magenta ink dots, and cyan ink dots can be arbitrarily selected. In the case of an ordinary multi-color or full-color image, a three-color separated image is formed according to the three-color signal, but when there are only two color signals, a corresponding two-color separated image is formed.

Thus, (A) a region where a color is developed by subtractive color mixing of at least two kinds of yellow, magenta and cyan, or (B) the region of (A) and yellow, magenta and cyan. A multicolor color image including an area formed by a combination with at least one type of monochrome area can be obtained. Here, the red color is at the overlapping portion of the yellow ink dots and the magenta ink dots, the green color is at the overlapping portion of the yellow ink dots and the cyan ink dots, and the blue color is at the overlapping portion of the magenta ink dots and the cyan ink dots. , A black color is presented at the overlapping portion of the yellow ink dots, the magenta ink dots, and the cyan ink dots.

In the above description, the black color is obtained by superimposing the yellow ink dot, the magenta ink dot, and the cyan ink dot, but the black color can be obtained only by the black ink dot without using the three color ink dots. You may

The black ink dots may be superposed on at least one of the yellow ink dots, the magenta ink dots, and the cyan ink dots, or may be superposed on at least two of them to give a black color.

When a printed image is formed using the thermal transfer recording material of the present invention, the printed image may be directly formed on the target transferred material, but it is previously printed on the sheet-shaped transferred material (image receiving material). After forming an image, the image-receiving member may be attached to a target transfer-receiving member by an appropriate means such as an adhesive.

As the image receptor, various plastic films (a concept including a sheet, the same applies hereinafter) such as a general polyethylene terephthalate film and a polyvinyl chloride resin film such as a polyvinyl chloride film can be used. Of course, a surface-treated image receptor for thermal transfer can also be used.

[0070]

Next, the present invention will be described with reference to examples.

Examples 1 to 9 and Comparative Examples 1 and 2 A 5 μm thick polyethylene terephthalate film was coated with a stick-prevention layer of 0.25 g / m ² of silicone resin on one side, and Table 1 was formed on the opposite side. The ink coating liquid shown in 1 is applied and dried, and the applied amount is 2 g / m ^2.
To form a heat-meltable ink layer to obtain a heat transfer recording material.

[0072]

[Table 1]

Using each of the above thermal transfer recording materials, a bar code pattern was printed on the following image receptor under the following conditions using a thermal transfer type bar code printer (B-30 manufactured by Tech Co., Ltd.). The images were evaluated for transferability and scratch resistance. Table 2 shows the results.

[Printing conditions] Applied energy: 22.6 mJ / mm ² Printing speed: 2 inches / second Platen pressure: Strong [Receptor] (A) Soft polyvinyl chloride film with a thickness of 70 μm (surface-treated) (PET) (hereinafter referred to as PVC film) (B) 100 μm thick polyethylene terephthalate film (not surface treated) (hereinafter PE
T film) [Transferability] About the obtained printed image RJS ENTERP
Reading was determined by a bar code reader (CODER SCAN II) manufactured by RISES, INC. The bar code reader criteria are as follows.

○ It is completely readable. △ Partially readable. × Unreadable.

[Scratch Resistance (Clocking Resistance)] Under the conditions shown below, the printed image after the test was read by a bar code reader in the same manner as described above.

Testing machine: A. Atlas Electric Device Co. A. A. T. C. C. Crockmeter model CM-1 Friction material: Cotton cloth Pressure: 500 g / cm ² Number of times: 300 times reciprocation [Scratch resistance (smear resistance)] For the printed image after the test under the conditions shown below, the bar is the same as above. The reading was judged by a code reader.

Test machine: Love tester manufactured by Yasuda Seiki Co., Ltd. Friction material: Cardboard Pressure: 250 g / cm ² times: 300 times reciprocating

[0079]

[Table 2]

[0080]

INDUSTRIAL APPLICABILITY The thermal transfer recording material of the present invention has excellent transferability (scratch) of the ink layer, good adhesion of the ink to various plastic films, and gives an image having excellent scratch resistance. It is useful for forming codes.

[Brief description of drawings]

FIG. 1 is a partial plan view showing an example of an arrangement of ink layers of respective colors in an embodiment of a thermal transfer recording material of the present invention.

[Explanation of symbols]

 1 Base Material 2Y Yellow Ink Layer 2M Magenta Ink Layer 2C Cyan Ink Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naohiro Ikeda 5-4-14 Minejima, Nishiyodogawa-ku, Osaka City, Osaka Prefecture Fujikopian Technology Center

Claims (3)

[Claims] 1. A thermal transfer recording material comprising a base material and a heat-meltable ink layer comprising at least a heat-meltable material and a colorant, wherein the heat-meltable material contains an epoxy resin in an amount of 30 to 90. % By weight, number average molecular weight of 30,000-
A thermal transfer recording material comprising 10 to 70% by weight of 300,000 acrylic resin. 2. The epoxy resin is one or more selected from the group consisting of tetraphenolethane tetraglycidyl ether, cresol novolac polyglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether. The thermal transfer recording material according to claim 1, wherein 3. The epoxy resin is one or two selected from the group consisting of tetraphenolethane tetraglycidyl ether, cresol novolac polyglycidyl ether and bisphenol F diglycidyl ether.
The thermal transfer recording material according to claim 1, wherein the thermal transfer recording material is one or more kinds.