JP2867761B2 - Thermal transfer recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables high-sensitivity and clear printing in any printing direction when printing various characters, particularly barcode patterns, on label paper or tag paper. The present invention relates to a thermal transfer recording medium.

[0002]

2. Description of the Related Art A transfer method using a thermal transfer recording medium is widely used in various fields. In addition to transferring image information and character information to general recording paper, the transfer method, apparel, and label industry Is also used when a bar code is attached to the packing material or the label to be attached as distribution management information or product management information.

Conventionally, when a heat-sensitive transfer recording medium comprising a base material such as a polyester film and a heat-sensitive transferable ink layer is used for printing a barcode or the like, the base material and the heat-sensitive transfer medium are used to improve the transferability. It has been proposed to provide a primer layer mainly composed of wax between the non-conductive ink layer (Japanese Patent Application Laid-Open Nos. 63-378390 and 61-20).
No. 6695, No. 62-242585, Japanese Patent Application Laid-Open No. 1-278390, No. 1-278389,
No. 1-247193).

[0004]

However, when a bar code pattern is printed by a thermal line head printer using a conventional thermal transfer recording medium having a primer layer formed mainly of wax, FIG.
When a pattern in the parallel direction parallel to the printing direction (arrow in the figure) of the printer is printed as shown in FIG. 2, clear printing is possible, but as shown in FIG. When a pattern in the serial direction perpendicular to (middle, arrow) is printed, the surface transfer of the thermal transfer ink layer and the phenomenon of so-called thickening of the bar occur, and as a result, the width of the black bar and the width (space) between the black bars are generated. 2) cannot be printed in the intended width, that is, the pattern width as shown in FIG. 2A, and there is a problem that a barcode is erroneously read.

[0005] Such a problem has occurred as follows. That is, since a considerable amount of heat remains in the thermal head even after the heat application voltage signal to the thermal line head is cut off, the thermal transfer ink layer of the thermal transfer recording medium is in a semi-molten state or a molten state at the time of transfer. It is close. Therefore, the adhesive force of the thermal transfer ink layer to the transfer paper is greater than the adhesive force of the thermal transfer recording medium to the primer layer. Therefore, as shown in FIG. 2B, when printing a serial pattern in the printing direction of the printer, when the transfer paper and the thermal transfer recording medium are peeled off by the paper feed of the printer, the thermal transfer ink layer is removed. Is in a semi-molten state, as shown in FIG. 3A, in addition to the black bar 31 which is the original printing portion, a planar stripped portion 32 whose edge is notched is formed. In the case where the thermal transfer ink layer is in a state close to a molten state at the time of transfer, FIG.
As shown in (b), thick bar width portions 34 are formed, and in each case, the actual print width is different from the original black bar 31.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is intended to print various characters, particularly barcodes, on label paper or tag paper in an arbitrary printing direction. It is another object of the present invention to provide a thermal transfer recording medium capable of performing clear printing with high sensitivity.

[0007]

In order to achieve the above object, the present invention relates to a thermal transfer recording medium comprising a substrate, a primer layer and a thermal transfer ink layer which are sequentially laminated, wherein the primer layer has an average molecular weight. Provided is a thermal transfer recording medium containing 7000 or less polyester.

That is, the thermal transfer recording medium of the present invention is characterized in that a primer layer mainly composed of a polyester resin is used instead of the conventional primer layer mainly composed of wax.

Hereinafter, the thermal transfer recording medium of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a thermal transfer recording medium of the present invention. In the thermal transfer recording medium of the present invention,
A substrate 1, a primer layer 2, and a thermal transfer ink layer 3 are sequentially laminated. Further, a heat-resistant lubricating layer 4 is laminated on the surface of the substrate 1 on which the primer layer 2 is not formed, if necessary.

The primer layer 2 of the thermal transfer recording medium of the present invention imparts transferability to the thermal transferable ink layer 3 so that the thermal transferable ink layer 3 is transferred with low energy, and the transfer is uniform. It is provided to prevent surface peeling and thickening of the bar width so that clear printing can be obtained. The polyester used for the primer layer 2 exhibits good adhesive strength from room temperature to a temperature at which the heat-sensitive transfer ink layer 3 is in a semi-molten state or a state close to a molten state at the time of transfer, and at a temperature at the time of transfer. Use a material that has a relatively low property. As a result, it is possible to prevent the surface transfer of the thermal transfer ink layer 3 and the phenomenon of increasing the width of the bar as described above, and the thermal transfer ink layer 3 is clearly transferred to the transfer paper.

Such polyesters include aliphatic dibasic acids such as adipic acid and sebacic acid, and aromatic dibasic acids such as phthalic acid and isophthalic acid, ethylene glycol,
Polycondensates with dialcohols such as neopentyl glycol can be used. In this case, the average molecular weight is 70
Use the following ones. This means that the average molecular weight is 70
If it exceeds 00, the melt viscosity of the primer layer itself is increased, and the transferability is reduced.

In the present invention, the primer layer contains at least 10% by weight of such a polyester, preferably at least 20% by weight. If the content is less than 10% by weight, it becomes difficult to prevent surface peeling and increase in bar width. The thickness of the primer layer is generally 0.05 to 2.0 μm, preferably 0.2 to 1.0 μm.

Incidentally, wax may be added to the primer layer 2 of the thermal transfer recording medium of the present invention, if necessary, in order to improve transferability in addition to the above-mentioned polyester. As the wax, the melting point of carbana wax, montan wax, oxidized wax, candelier wax, microcrystalline wax, rice wax, etc. is 5
A wax at 0-150 ° C. can be used. Further, ethylene / vinyl acetate copolymer, terpene resin,
Thermoplastic resins such as rosin and styrene resin may be blended.

The substrate 1 of the thermal transfer recording medium of the present invention may be a film sheet such as a polyester film, a polyimide film, a polycarbonate film or the like or a capacitor generally used as the substrate of the thermal transfer recording medium. Paper or the like can be used.

Further, as the thermal transfer ink layer 3, a layer formed from a heat-melt type thermal transfer ink conventionally used for a thermal transfer recording medium can be used.
For example, waxes having a melting point of 50 to 150 ° C. such as carbana wax, montan wax, oxidized wax, candelier wax, microcrystalline wax, and rice wax, and thermoplastics such as ethylene / vinyl acetate copolymer, terpene resin, rosin, and styrene resin. An ink in which a colorant such as a resin, carbon black, an organic pigment, an inorganic pigment, and a dye, and a filler such as silica, mica, and a silicone resin are uniformly mixed can be used.

A heat-resistant lubricating layer 4 provided on one side of the base material 1 as necessary prevents sticking and allows the thermal transfer recording medium to run smoothly. It is made of a resin having excellent heat resistance such as a silicone resin or a nitrocellulose resin, or a resin obtained by adding a lubricant such as a silicone oil or a fluorine powder to these resins.

The thermal transfer recording medium of the present invention as described above can be manufactured according to a conventional method. For example, a composition for a heat-resistant lubricating layer is applied to one surface of the substrate 1 using a gravure coater and dried to form a heat-resistant lubricating layer 4, and a primer is applied to the other surface of the substrate 1 using a gravure coater. The primer layer 2 is formed by applying a layer composition and drying to form a primer layer 2, and a thermal transfer ink is further applied thereon using a gravure coater and dried to form a thermal transfer ink layer 3.

[0019]

According to the thermal transfer recording medium of the present invention, the temperature of the thermal transfer ink layer 3 is set between the substrate 1 and the thermal transfer ink layer 3 from room temperature.
Up to a temperature near the semi-molten state to a state close to the molten state at the time of transfer, and has an average molecular weight of 7 so as to easily melt at the temperature at the time of transfer to lower the adhesiveness.
Since the primer layer 2 having a polyester of 000 or less as a main component is provided, even when a barcode pattern is printed in an arbitrary direction, it is possible to prevent the surface peeling of the thermal transfer ink layer 3 and the phenomenon of increasing the bar width. Make it possible. Furthermore, the primer layer 2 containing at least 10% by weight of such a polyester has a relatively low adhesiveness at the temperature at the time of transfer, so that the thermal transfer ink layer 3 can be clearly transferred to transfer paper. I do.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 XA was applied to one surface of a 4.8 μm thick polyester film.
An about 10% by weight MEK solution of -9700 (trade name, polyester having an average molecular weight of 1800, manufactured by Unitika Ltd.) is applied using a wire bar so as to have a dry thickness of 0.5 μm, and dried at 110 ° C. And a primer layer was formed.

On this primer layer, 40 parts by weight of paraffin wax (melting point: 75 ° C., manufactured by Nippon Seiro Co., Ltd.), 40 parts by weight of carnauba wax (melting point: 81 ° C., manufactured by Toyo Petrolite Co., Ltd.), ethylene-vinyl acetate copolymer 10 parts by weight of coalescing (KA-31, manufactured by Sumitomo Chemical Co., Ltd.), carbon black (MA-100, manufactured by Mitsubishi Chemical Corporation)
A mixture of 10 parts by weight and 100 parts by weight of toluene is heated to 70 ° C.
The resultant was heated and dissolved, and the resultant was coated and dried using a wire bar so as to have a dry thickness of 3 μm to form a thermal transfer ink layer.

A printer (B-3) having a thermal line head is used for the thermal transfer recording medium thus obtained.
0, TEC Co., Ltd.) and a dot density of 7.6 do
Under the conditions of t / mm and a printing speed of 50.4 mm / sec, a Code39 pattern, which is a type of barcode pattern, was printed in serial direction on transfer paper. The printing energy is such that the deviation from the standard value of the bar code pattern is 0 when the Code 39 pattern is printed in the parallel direction.
The energy was set to be μm.

With respect to the obtained barcode pattern, the deviation of the bar width from the standard value, the increase of the bar width, the surface peeling, the transferability and the overall evaluation as a thermal transfer recording medium were evaluated as follows. Table 1 shows the obtained results. (A) Deviation from the standard value of bar width The deviation of the printed Code39 from the standard width of each of the black bar and the space is measured using a bar code verifier, and the obtained values are averaged to obtain the bar width. Was deviated from the standard value. It can be said that this numerical value is 0, which is an ideal printing. When the code 39 is 3: 9 dots, the magnitude of the deviation from the permissible standard value can be calculated to be 136 μm. If the deviation is larger than this, erroneous reading of the barcode occurs or reading becomes impossible. (B) Wide bar width Adhesive tape (cellotape,
Paste Nichiban), peel off the transfer paper and adhesive tape so that only the peeled surface is peeled off without peeling off the surface of the transfer paper, and check the deviation from the standard width of each black bar and space after peeling. It measured using the barcode verifier, and made the average value of the obtained values into the bar width thickening value. It can be said that the smaller the value is, the more preferable the printing result is. (C) Planar peeling The degree of planar peeling was calculated according to the following equation.

(Surface peeling value) = (Deviation value of bar width from standard value) − (Bar width thickening value) The smaller this value is, the more preferable the printing result is. (D) Transferability The transfer state of the barcode pattern was visually observed. In the table, ◎ indicates a very good transfer state, 、 indicates a good transfer state, Δ indicates a sticking state, and X indicates a sticking state. (E) Comprehensive evaluation In the table, there is no possibility of erroneous reading or inability to read the barcode, and the transferability is good.

As is clear from Table 1, the bar code printed by using the thermal transfer recording medium of this embodiment has a deviation from the standard value of the bar width within an allowable range and has excellent transferability. Was.

Example 2 As a composition for forming a primer layer, XA-9 was used.
700 (trade name, polyester having an average molecular weight of 1800,
Example 1 was repeated except that a MEK solution having a weight ratio of 1: 1 between Unitika Ltd. and carnauba wax was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this embodiment has a deviation from the standard value of the bar width within an allowable range and has excellent transferability. Was.

Example 3 As a composition for forming a primer layer, XA-9 was used.
700 (trade name, polyester having an average molecular weight of 1800,
Example 1 was repeated except that a MEK solution having a weight ratio of 3: 7 between Unitika Co., Ltd.) and carnauba wax was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this embodiment has a deviation from the standard value of the bar width within an allowable range and has excellent transferability. Was.

Example 4 XA-9 was used as a composition for forming a primer layer.
700 (trade name, polyester having an average molecular weight of 1800,
Example 1 was repeated except that a MEK solution having a weight ratio of 2: 8 between Unitika Ltd. and carnauba wax was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is apparent from Table 1, the bar code printed using the thermal transfer recording medium of this embodiment has a deviation from the standard value of the bar width within an allowable range and has excellent transferability. Was.

Example 5 As a composition for forming a primer layer, XA-3
300 (trade name, polyester having an average molecular weight of 7000,
Example 1 was repeated except that a 10% by weight MEK solution (produced by Unitika Ltd.) was used to obtain a thermal transfer recording medium.
Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.
Shown in

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this embodiment has a deviation from the standard value of the bar width within an allowable range and has excellent transferability. Was.

Comparative Example 1 A thermal transfer recording medium was obtained by repeating Example 1 except that a thermal transfer ink layer was formed on a polyester film as a base material without using a primer layer. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this comparative example has satisfactory transferability, but the deviation of the bar width from the standard value is acceptable. It was out of range.

Comparative Example 2 A thermal transfer recording medium was obtained by repeating Example 1 except that a carnauba wax MEK dispersion was used as a composition for forming a primer layer. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed by using the thermal transfer recording medium of this comparative example has satisfactory transferability, but the deviation of the bar width from the standard value is allowable. It was out of range.

Comparative Example 3 UE32 was used as a composition for forming a primer layer.
00 (trade name, polyester having an average molecular weight of 15,000,
Example 1 was repeated except that a 10% by weight MEK solution (produced by Unitika Ltd.) was used to obtain a thermal transfer recording medium.
Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.
Shown in

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this comparative example has a deviation from the standard value of the bar width exceeding an allowable range, and has a good transferability. It was bad.

Comparative Example 4 UE-3 was used as a composition for forming a primer layer.
Example 1 was repeated except that a MEK solution having a weight ratio of 200 (trade name, polyester having an average molecular weight of 15,000, manufactured by Unitika Ltd.) to carnauba wax was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this comparative example has satisfactory transferability, but the deviation of the bar width from the standard value is acceptable. It was out of range.

Comparative Example 5 As a composition for forming a primer layer, Tomide # 90 (trade name, polyamide having an average molecular weight of 2300,
10% by weight (Toluene / I)
PA) A thermal transfer recording medium was obtained by repeating Example 1 except that a solution was used. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this comparative example has a deviation from the standard value of the bar width exceeding an allowable range, and has a good transferability. It was bad.

Comparative Example 6 A 10% by weight (toluene / IPA) solution of tomide # 397 (trade name, polyamide having an average molecular weight of 3400, manufactured by Fuji Chemical Industry Co., Ltd.) was used as a composition for forming a primer layer. Example 1 was repeated except that the thermal transfer recording medium was used. Using the obtained thermal transfer recording medium, a barcode pattern was printed and evaluated in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the bar code printed using the thermal transfer recording medium of this comparative example has a deviation from the standard value of the bar width exceeding an allowable range, and also has a good transferability. It was bad.

[0047]

[Table 1]  Bar width standard value Bar width thicker Surface peeling Transferability Comprehensive evaluationDeviation (μm) (μm) (μm) Example 1 +110 +99 +11 ○ ○ 2 +120 +107 +13 ○ ○ 3 +120 +114 +6 ○ ○ 4 +120 +108 +12 ○ ○ 5 +110 +108 +2 ○ ○ Comparative Example 1 +140 +118 +22 ○ X 2 +150 +121 +29 +29 +29 +29 +29 △ X 4 +160 +127 +33 ○ X 5 +130 +110 +20 △ X6 +120 +110 +10 X X

[0048]

According to the thermal transfer recording medium of the present invention,
When printing various characters, especially barcodes, on label paper or tag paper, the deviation from the standard value of the bar width is within the allowable range in any printing direction, and high sensitivity and clear printing Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a thermal transfer recording medium of the present invention.

FIG. 2 is an explanatory diagram when a barcode pattern is printed in a serial direction and a parallel direction.

FIG. 3 is an explanatory diagram of a state in which a bar code pattern is increased in a planar peeling bar width.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Primer layer layer 3 Thermal transfer ink layer 4 Heat resistant slip layer

Claims (2)

(57) [Claims] 1. A heat-sensitive transfer recording medium comprising a base material, a primer layer and a heat-sensitive transfer ink layer sequentially laminated, wherein the primer layer contains a polyester having an average molecular weight of 7000 or less. 2. The average molecular weight of the primer layer is 7,000.
2. The thermal transfer recording medium according to claim 1, wherein the content of the following polyester is at least 10% by weight.