JPH0558066A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain sharp printing with high sensitivity with respect to an arbitrary printing direction when a character of every kind, especially, a bar code is printed on label paper or tag paper using a thermal transfer recording medium. CONSTITUTION:When a thermal transfer recording material is produced by successively laminating a base material 1, a primer layer 2 and a thermal transfer ink layer 3, at least 10wt.% of polyester is used as the main component of the primer layer 2. Especially, polyester with an average mol.wt. of 7000 or less is pref.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables clear printing with high sensitivity in any printing direction when printing various characters, especially bar code 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 heat-sensitive 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, the apparel and the label industry are used. It is also used in the case of attaching a bar code as distribution management information or merchandise management information to packaging materials, sticking labels and the like.

Conventionally, when a heat-sensitive transfer recording medium comprising a base material such as a polyester film and a heat-sensitive transfer ink layer is used for printing a bar code or the like, the base material and the heat-sensitive transfer are used to improve the transferability. It has been proposed to provide a primer layer containing a wax as a main component between the ink layer and the volatile ink layer (JP-A-63-378390 and 61-20).
No. 6695, No. 62-242585, 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, as shown in FIG. 2 (a).
As shown in Fig. 2, clear printing is possible when a pattern in the parallel direction parallel to the printing direction of the printer (arrow in the figure) is printed, but as shown in Fig. 2 (b), the printing direction of the printer (Fig. When a pattern in the serial direction perpendicular to the middle and arrow) is printed, surface peeling of the thermal transfer ink layer and the phenomenon of so-called bar width thickening occur, and as a result, the width between black bars and the space between black bars (space) 2) could not be printed in the width intended, that is, the pattern width as shown in FIG. 2A, and there was a problem that the bar code was misread.

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 during transfer. It is close. Therefore, the adhesive force of the thermal transfer ink layer to the transfer paper is larger than the adhesive force to the primer layer of the thermal transfer recording medium. Therefore, as shown in FIG. 2B, when the pattern in the serial direction is printed in the printing direction of the printer, when the transfer paper and the thermal transfer recording medium are peeled off by the paper feeding of the printer, the thermal transfer ink layer. 3 is in a semi-molten state, as shown in FIG. 3 (a), in addition to the black bar 31 which is the original print portion, a sheet-like peeling portion 32 having a jagged end is formed (in the figure, the arrow indicates In the case where the heat-sensitive transfer ink layer is in a state close to the melted state at the time of transfer,
As shown in (b), the bar width thick portion 34 is formed, and the actual print width of each is different from the original black bar 31.

The present invention is intended to solve the above-mentioned problems of the prior art, and when printing various characters, particularly a bar code, on a label paper or a tag paper, the printing paper can be printed in any printing direction. An object of the present invention is to provide a heat-sensitive transfer recording medium capable of high-sensitivity and clear printing.

[0007]

In order to achieve the above object, the present invention provides a heat-sensitive transfer recording medium comprising a substrate, a primer layer and a heat-sensitive transfer ink layer, which are laminated in that order. There is provided a thermal transfer recording medium characterized by containing at least 10% by weight of a polyester resin.

That is, the heat-sensitive transfer recording medium of the present invention is characterized by using a primer layer mainly composed of a polyester resin, instead of the conventional primer layer mainly composed of wax.

The thermal transfer recording medium of the present invention will be described below 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 base material 1, a primer layer 2, and a thermal transfer ink layer 3 are sequentially laminated. Further, a heat resistant slipping layer 4 is laminated on the surface of the base material 1 on which the primer layer 2 is not formed, if necessary.

The primer layer 2 of the heat-sensitive transfer recording medium of the present invention imparts transferability to the heat-sensitive transferable ink layer 3 so that the heat-sensitive transferable ink layer 3 transfers with low energy, and the transfer is uniform. In addition, it is provided in order 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 a good adhesive force 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 adheres at the temperature at the time of transfer. Use the one whose sex is relatively lowered. As a result, it is possible to prevent the phenomenon such as the above-described peeling of the surface of the heat-sensitive transfer ink layer 3 and the thickening of the bar width, and the heat-transfer ink layer 3 is clearly transferred to the transfer paper.

Examples of such polyesters include polycondensation of aliphatic dibasic acids such as adipic acid and sebacic acid and aromatic dibasic acids such as phthalic acid and isophthalic acid with dialcohols such as ethylene glycol and neopentyl glycol. It is possible to use those having an average molecular weight of 7,000.
The following are preferred. It has an average molecular weight of 7,000
This is because if it is larger than the above range, the transferability is lowered.

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

In addition to the above-mentioned polyester, a 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. As the wax, carnauba wax, montan wax, oxide wax, candelhi wax, microcrystalline wax, rice wax and the like have a melting point of 5 or less.
Waxes from 0 to 150 ° C can be used. Furthermore, ethylene / vinyl acetate copolymer, terpene resin,
You may mix thermoplastic resins, such as rosin and styrene resin.

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

As the heat-sensitive transfer ink layer 3, a layer of heat-melting type heat-sensitive transfer ink, which has been conventionally used in heat-sensitive transfer recording media, can be used.
For example, waxes having a melting point of 50 to 150 ° C. such as carnauba wax, montan wax, oxide wax, candelilla wax, microcrystalline wax, and rice wax, thermoplastic resins 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 or a dye, and a filler such as silica, mica or a silicone resin are uniformly mixed can be used.

The heat resistant slipping layer 4 provided on one surface of the substrate 1 as necessary prevents sticking and allows the thermal transfer recording medium to smoothly run, and includes a silicone resin, a fluororesin and an acrylic resin. It is made of a resin having excellent heat resistance such as a silicone resin or a nitrocellulose resin, or one obtained by adding a lubricant such as silicone oil or fluorine powder to these resins.

The thermal transfer recording medium of the present invention as described above can be manufactured by a conventional method. For example, the composition for a heat resistant slipping layer is applied to one surface of the base material 1 using a gravure coater and dried to form the heat resistant slipping layer 4, and the primer is applied to the other surface of the base material 1 using the gravure coater. It can be produced by applying a layer composition and drying it to form a primer layer 2, and then applying a heat-sensitive transfer ink thereto using a gravure coater and drying it to form a heat-sensitive transfer ink layer 3.

[0019]

The heat-sensitive transfer recording medium of the present invention comprises a heat-sensitive transfer ink layer 3 at a room temperature between the substrate 1 and the heat-sensitive transfer ink layer 3.
Since a primer layer containing polyester as a main component, which shows good adhesive strength up to a temperature in which the semi-molten state or a state close to the molten state during transfer is provided, even when a bar code pattern is printed in any direction It is possible to prevent the surface peeling of the heat-sensitive transfer ink layer 3 and the bar width phenomenon. Further, since the adhesiveness of the primer layer 2 containing at least 10% by weight of such polyester is relatively lowered at the temperature at the time of transfer, the thermal transfer ink layer 3 can be clearly transferred to the transfer paper. ..

[0020]

EXAMPLES The present invention will be specifically described below with reference to examples, but the invention is not limited to these examples.

Example 1 XA was applied to one side of a 4.8 μm thick polyester film.
About 9 wt% MEK solution of -9700 (trade name, polyester having an average molecular weight of 1800, manufactured by Unitika Ltd.) was applied using a wire bar to a dry thickness of 0.5 μm, and dried at 110 ° C. , A primer layer was formed.

On this primer layer, 40 parts by weight of paraffin wax (melting point 75 ° C., manufactured by Nippon Seirou Co., Ltd.), 40 parts by weight of carnauba wax (melting point 81 ° C., manufactured by Toyo Petrolite Co., Ltd.), ethylene-vinyl acetate copolymer Combined (KA-31, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts by weight, carbon black (MA-100, manufactured by Mitsubishi Kasei Co., Ltd.)
Mix a mixture of 10 parts by weight and 100 parts by weight of toluene at 70 ° C.
A heat-sensitive transfer ink layer was formed by applying a solution obtained by heating and dissolving the solution to a dry thickness of 3 μm using a wire bar and drying.

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

With respect to the obtained bar code pattern, the deviation from the standard value of the bar width, bar width thickening, surface peeling, transferability and comprehensive evaluation as a thermal transfer recording medium were evaluated as follows. The results obtained are shown in Table 1. (A) Deviation of bar width from standard value The deviation of the printed Code 39 from the standard width of each black bar and space was measured using a bar code verifier, and the obtained values were averaged to obtain the bar width. Deviation from the standard value of. It can be said that ideal printing is when this value becomes 0. When the code 39 is 3: 9 dot, the size of the deviation from the allowable standard value can be calculated to be 136 μm, and if the deviation exceeds this value, the bar code may be erroneously read or unreadable. (B) Over the bar width bar code pattern Adhesive tape (cellophane tape,
Nichiban) is attached, the transfer paper and adhesive tape are peeled off so that only the peeled part on the surface is peeled off without peeling off the surface of the transfer paper, and the deviation from the standard width of each black bar and space after peeling It measured using the bar code verifier, and made the average value of the obtained value the bar width thick value. It can be said that the smaller this value is, the more preferable printing result. (C) Surface peeling The degree of surface peeling was calculated according to the following formula.

(Area peeling value) = (Deviation value of bar width from standard value)-(Bar width thickening value) It can be said that the smaller this value is, the more preferable printing result. (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 case of sticking, and X indicates a case of sticking. (E) Comprehensive Evaluation In the table, ◯ indicates that there is no possibility of erroneous reading or unreadable bar code and transferability is good, and X indicates that it does not.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this example has a deviation of the bar width from the standard value within an allowable range and has excellent transferability. It was

Example 2 As a composition for forming a primer layer, XA-9
700 (trade name, polyester with an average molecular weight of 1800,
A thermal transfer recording medium was obtained by repeating Example 1 except that a MEK solution having a weight ratio of 1: 1 by Unitika Ltd. and carnauba wax was used. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this example has a deviation of the bar width from the standard value within an allowable range and has excellent transferability. It was

Example 3 XA-9 was used as a composition for forming a primer layer.
700 (trade name, polyester with an average molecular weight of 1800,
A thermal transfer recording medium was obtained by repeating Example 1 except that a MEK solution having a weight ratio of Unitika Co., Ltd.) and carnauba wax of 3: 7 was used. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

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

Example 4 As a composition for forming a primer layer, XA-9
700 (trade name, polyester with an average molecular weight of 1800,
A thermal transfer recording medium was obtained by repeating Example 1 except that a MEK solution in which the weight ratio of Unitika Ltd.) and carnauba wax was 2: 8 was used. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this example has a deviation of the bar width from the standard value within an allowable range and is excellent in transferability. It was

Example 5 As a composition for forming a primer layer, XA-3
300 (trade name, polyester with an average molecular weight of 7,000,
Example 1 was repeated except that a 10% by weight MEK solution (manufactured by Unitika Ltd.) was used to obtain a thermal transfer recording medium.
Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this example has a deviation of the bar width from the standard value within an allowable range and has excellent transferability. It 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 substrate without using a primer layer. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

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

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

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

Comparative Example 3 UE32 was used as a composition for forming a primer layer.
00 (trade name, polyester with an average molecular weight of 15,000,
Example 1 was repeated except that a 10% by weight MEK solution (manufactured by Unitika Ltd.) was used to obtain a thermal transfer recording medium.
Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.
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 of the bar width from the standard value within the allowable range and also has transferability. It was bad.

Comparative Example 4 As a composition for forming a primer layer, UE-3
A thermal transfer recording medium was obtained by repeating Example 1 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.) and carnauba wax was 1: 1. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

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

Comparative Example 5 As a composition for forming a primer layer, Thomide # 90 (trade name, polyamide having an average molecular weight of 2300,
10% by weight of Fuji Kasei Kogyo Co., Ltd. (toluene / I
Example 1 was repeated except that the (PA) solution was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this comparative example had a deviation of the bar width from the standard value within the allowable range and also had transferability. It was bad.

Comparative Example 6 As a composition for forming a primer layer, a 10 wt% (toluene / IPA) solution of Thomaid # 397 (trade name, polyamide having an average molecular weight of 3400, manufactured by Fuji Kasei Kogyo Co., Ltd.) was used. Example 1 was repeated except that it was used to obtain a thermal transfer recording medium. Using the obtained thermal transfer recording medium, a bar code pattern was printed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, the bar code printed using the heat-sensitive transfer recording medium of this comparative example had a deviation of the bar width from the standard value within the allowable range and also had transferability. It was bad.

[0047]

[Table 1]  Standard value of bar width or thick bar width 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 +160 +121 +12 +12 ◎ △ 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 You can

[Brief description of 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 planar peeling bar width of a barcode pattern is thickened.

[Explanation of symbols]

 1 Base Sheet 2 Primer Layer 3 Thermal Transfer Ink Layer 4 Heat Resistant Sliding Layer

Claims (2)

[Claims] 1. A heat-sensitive transfer recording medium comprising a substrate, a primer layer and a heat-sensitive transfer ink layer which are successively laminated, wherein the primer layer contains at least 10% by weight of polyester. Medium. 2. The polyester has an average molecular weight of 7,000.
The thermal transfer recording medium according to claim 1, wherein: