JPS60127193A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To enhance transfer sensitivity and enable to print with low energy, by incorporating 1,2-polybutadiene into a coloring material layer. CONSTITUTION:A thermal transfer recording medium has a single coloring material layer on a base, which layer comprises 1,2-polybutadiene, which may be liquid or resinous and preferably has a molecular weight of 1,000-200,000. A hard wax and a soft wax are used in combination as a heat-fusible substance. A base preferably has thermal stability, high dimensional stability and high surface smoothness. Accordingly, it is possible to print with low energy, contamination of ground of an ordinary paper is prevented, and a coloring matter transferred image is obtained with high resolution and favorable fixability.

Description

[Detailed description of the invention] [Technique!・Transfer field] The present invention relates to a thermal transfer recording medium. Specifically, the present invention relates to a thermal transfer recording medium that has high transfer sensitivity and can be printed with low energy, and that does not cause background smear (fog) on the recording sheet such as when paper is passed through the paper. The present invention relates to a heat-sensitive transfer recording medium that can suppress the occurrence of color transfer, has excellent fixing properties to a recording sheet, and provides a dye transfer image with high resolution.

[Prior Art] A thermal transfer recording medium has been conventionally used as a recording medium for transferring and forming an image on a recording sheet such as a burst paper using a thermal printer, a thermal facsimile, or the like. This thermal transfer recording medium has at least one coloring material layer on a support, and the coloring material layer includes, for example, a layer containing a coloring agent made of a dye such as a pigment and a heat-fusible substance. etc. are known. As the heat-melting substance, a low melting point substance such as wax or wax is used.

In addition, as a support, in order to obtain good development properties of the dye transfer image obtained from the color material layer coated on this layer, films etc. having excellent surface smoothness and judicial stability are used. is used.

When using a thermal printer or thermal facsimile with a thermal head to record a dye transfer image on a sheet of paper using such a thermal transfer recording medium, it is desirable to print with low energy. However, the transfer sensitivity of conventional thermal transfer recording media was low and insufficient.

Furthermore, there was also the drawback that background stains (fogging) occurred on the recording sheet.

For example, Japanese Patent Publication No. 51-30804 discloses a coloring material layer consisting of adhesive resin, wax, ethylene-vinyl acetate copolymer, and inorganic filler, and Japanese Patent Publication No. 57-105395 The publication states that the resin has a softening point or melting point of 50 to 130°C, a glass transition point of 45°C or higher, a breaking elongation of 10% or less, and a melt viscosity at 150'C of L02-10'cp. (A), a resin (B) having a softening point or melting point of 80°C or higher, a glass transition point of 20°C or lower, and a breaking elongation of 50% or higher, and a coloring agent. is disclosed, and ・J)
JP-A-58-101094 discloses a coloring material layer comprising an A coloring agent, a waxy substance, a polyethylene wax, and a rosin polymer compound. 2) If these heat-sensitive transfer recording media having two color material layers are designed to have a relatively low transfer sensitivity, clear dye transfer images without background stains (fogging) can be obtained. If the transfer sensitivity is designed to be high, not only will background stains (fog) occur on the paper, but also problems will arise in the fixability and resolution of the dye transfer image.

On the other hand, as one method for increasing transfer sensitivity, a technique for improving the thermal conductivity of a coloring material layer is disclosed in Japanese Patent Laid-Open No. 75894/1983. The invention is a technology for containing a powdered thermally conductive substance in a coloring material layer, and since it requires the use of additives, the coloring material layer may become thick depending on the type of additive, resulting in poor resolution. There were cases where it decreased. Furthermore, there was also the drawback that background stains (fogging) occurred on recording sheets such as plain paper.

[Object of the Invention] An object of the present invention is to provide a thermal transfer recording medium that has high transfer sensitivity and can be printed with low energy.

Another object of the present invention is to be able to suppress the occurrence of background stains (fogging) on recording sheets such as plain paper, and to obtain dye transfer images with high resolution if the fixing properties are good. An object of the present invention is to provide a thermal transfer recording medium.

Further objects of the invention will become apparent from the following description of the tree specification.

[Summary of the Invention] As a result of intensive research, the inventor has developed a thermal transfer recording medium having a coloring material layer containing a heat-fusible substance on a support, in which the coloring material layer is made of 1,2-polybutadiene. It has been discovered that the above object can be achieved by containing the following, leading to the present invention.

Therefore, in order to achieve the above-mentioned object 1, the inventor of the present invention achieved the above-mentioned object of the present invention by selecting specific resins rather than the conventional method of adding a thermally conductive substance. He succeeded in doing so.

By using two specific types of wax in combination, they succeeded in achieving even better effects.

[Structure of the invention] The present invention will be described in further detail below.

The thermal transfer recording medium of the present invention has at least one coloring material layer on a support. The coloring material layer contains 1,2-polybutadiene. The 1,2-polybutadiene of the present invention includes liquid and resin forms, and has a molecular weight of 1.000 to 20.
A value of 0.000 is preferred. The 1,2-polybutadiene of the present invention may be modified by epoxidation modification, acrylic modification, ester modification, boiling modification, urethane modification, etc.
Moreover, a part of it may be hydrogenated. 1.2 of the present invention
- An example of a polybutadiene compound is Nl manufactured by Nippon Shuda
5SO-PB B-1000゜B-'2000, B-
3000, B-4000, BF-1000, TE-20
00, GM-2000.

G1-1000. GQ-1000, TP-1000, F
irestone Tire and Rubber C
o, FOR-1261, Richard Co.
RICON+50.11 JSRRB- made of wood synthetic rubber
810, RB-820, RB-830゜RBT-814
, RBT-818 and the like.

The 1,2-polybutadiene of the present invention may be used partially or partially cured with a general crosslinking agent such as diisocyanate-1 and a radical polymerization initiator, or may be used in combination of two or more types. There may be. Furthermore, it may be used in combination with other known resins.

The hue layer of the present invention contains a heat-fusible substance. As the heat-melting substance, it is preferable to use a combination of at least one kind of hard wax and at least one kind of soft wax.

The hard wax used in the present invention is 25°C (100g
) is a wax having a penetration degree of less than 8. The measurement of button size is based on JIS K 2530. And the melting point (al wood MPJ-2 type Niyor measurement value) 50-12
Materials at 0°C are preferred. Specific examples of the hard waxes used in the present invention include (1) Ester waxes (natural ester waxes such as Karnahawa wax and Montan wax, and Hoechst Wax E and F manufactured by Hoechst Company).

KP, KPS, BJ, OP, ON, X22. U OJ:
(■ Oxidized wax (wax obtained by oxidizing wax such as paraffin wax and microcrystalline wax), [NPS-9210, NPS-8115 manufactured by Wood Wax 1, PETR0NABA IIC, C manufactured by Toyo Petrolite Co., Ltd.
/1RD1S 314, Hoec made by Hekis i-1
hst Wax S, L, LP, etc.) ■Low molecular part - polyethylene wax (especially those with molecules 1.300 to 1000, POLYWAX 500 manufactured by Toyo Petrolite Co., Ltd.)
and 655, etc.).

On the other hand, the soft wax used in the present invention is heated at 25°C (1
The wax has a penetration degree of 8 or more in 00g).

And melting point (A11i value by Yanagiki MPJ-2 type) 5
Materials with a temperature of 0 to 120°C are preferred. As a specific example of the soft wax used in the present invention, micro wax (1
1 stone Micro Wax 155.180 (manufactured by II Kiyu Co., Ltd.), old-MIC Knee 1080. Old-MIC-2065
, Old-Old C-2095.

Old-MIC knee 1070. Old-MIG-1045, Old-
Old C-2045 (manufactured by Hiki Seirosha), 5TARWAX
100. BE 5QUARE 175,185°V [
: TORY, ULTRAFLEX (manufactured by Toyo Petrolite Co., Ltd.), stearic acid, behenic acid, stearyl alcohol, white wax, beeswax, dodecyl stearate, stearone, solhitan monostearate, polyoxyethylene monostearate 1 The coloring agent to be contained in the coloring material layer of the present invention may be appropriately selected from conventionally known pigments, such as direct dyes, durable dyes, basic dyes, disperse dyes, and oil-soluble dyes. You can choose from among these. The coloring matter used in the coloring material layer of the present invention may be any pigment that can be transferred (transferred) together with the heat-melting substance, so that it may be a pigment in addition to the above.

Although the composition ratio of the coloring material layer of the present invention is not limited, 5 to 80 parts of hard wax, 5 to 80 parts of soft wax to 100 parts (parts by weight, the same applies hereinafter) of the total coloring material layer, The coloring agent is 5 to 40 parts, and the 1,2-polybutadiene of the present invention is 01 parts.
~40 parts (more preferably 1 to 20 parts). The composition ratio of hard wax and soft wax of the present invention is l
:9 to 9:1, more preferably 2:8 to 8:2.

The color material layer of the present invention may contain various additives in addition to the above components. For example, as a softener, castor oil,
Vegetable oils such as linseed oil, olive oil, animal oils such as whale oil, and mineral oils may suitably be used.

The support used as a base material for the thermal transfer recording medium of the present invention preferably has heat-resistant strength, high dimensional stability, and high surface smoothness. Definite strength requires strength and dimensional stability to maintain the toughness of a support that does not soften or plasticize due to the heating temperature of a heat source such as a thermal head, and surface smoothness requires It is desired that the layer containing the fusible substance has sufficient smoothness to exhibit a good transfer rate.

The smoothness was measured using a Beck tester (JISP).
8119) for 100 seconds or more, and 300 seconds
If it is ec or more, an image with better transfer rate and reproducibility can be obtained. Materials include, for example, papers such as plain paper, capacitor paper, laminated paper, coated paper, resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, polyimide, paper-resin film composites, aluminum foil, etc. Metallic seams 1, etc. are preferably used. The thickness of the support is usually about 8 Qgm or less, especially 2 to 2 Qgm, in order to obtain good thermal conductivity.
Preferably, it is 20 parts m. In the thermal transfer recording bW body of the present invention, the structure of the back side of the support is arbitrary.

Techniques suitable for applying the colorant layer to a support such as a polymer film in the thermal transfer recording medium of the present invention are known in the art, and these techniques can also be used in the present invention. For example, the coloring material layer is a layer formed by applying the composition by melt coating, or by applying a coating solution prepared by dissolving or dispersing the composition in an appropriate solvent and coating it with a coating solution. As a coating method for the coloring material layer of the present invention, any known technique can be employed, such as a reverse roll coater method, an extrusion coater method, a graphia coater method, and a wire/hair coating method. The color material layer of the present invention may have a thickness of 15 pLm or less, preferably 2 to 8 pLm.

Effects of the Invention According to the invention, in a thermal transfer recording medium having a coloring material layer containing a heat-melting substance on a support, the coloring material layer contains 1,2-polybutadiene of the present invention. Therefore, the objective of the present invention mentioned above can be achieved, and high-speed recording (printing) is also possible due to the high sensitivity.

[Example] Examples will be given below to demonstrate the implementation of the present invention! The appearance is not limited to these, and "part U" used below refers to "parts by weight."

Example 1 The following coloring material layer compositions (a), (b) and (C) were mixed into 6p-
Apply it to a dry thickness of 3.5 lj.m on a polyethylene terephthalate film with a thickness of m.

Thermal transfer recording medium samples (A), (B) and (
G) was obtained.

Coloring material layer composition (a) Ester wax (Hoechst WaxF, manufactured by Hoechst) (melting point 7
4 to 80°C, needle strength 3.5) 55 parts microcrystalline wax (LILTRAFLEX, manufactured by Toyo Petrolite) (melting point 65°C, button strength 28) 25 parts syndiotactic-1,2-polybutadiene (JSRRBT) -816, manufactured by Japan Synthetic Rubber Co., Ltd.) 5 parts Carbon black 158 Color material layer composition (b) Oxidized wax (NPS-9210, manufactured by Hiki Seiro Co., Ltd.) (melting point 78°C, degree of side penetration 5) 37 parts Microcrystalline wax 155.
-810, manufactured by Japan Synthetic Rubber Co., Ltd.) 5 parts Carbon black 15 parts Coloring material layer composition (C), 1,2-polybutadiene (NISSO-PHB-4QO0, manufactured by G Honsoda Co., Ltd.) 15
1 part Incyanate (Takenate D-11ON, manufactured by Takeda Pharmaceutical Co., Ltd.) 2 parts Carbon black 15 parts Example 2 The only difference is that 80 parts of ester wax was used instead of microcrystalline wax in the colorant layer composition (a). In addition, a thermal transfer recording medium sample of the present invention (D
) was obtained.

Comparative Example 1 In the colorant layer composition (a), ethylene-vinyl acetate was used instead of 1,2-polybutadiene (polymerization ratio 72/2).
A comparative thermal transfer recording medium sample (E) was obtained in the same manner except that 8) was used. The thermal transfer recording medium samples obtained in the above Examples and Comparative Examples were printed using a thermal printer (
A prototype machine equipped with a thin 1Q type line thermal head with a heating element density of 8dot/I1m. ) was printed on Ig passing paper, and the results shown in Table 1 were (+1.).

111 Using the thermal printer, the stamping process was done from O to 0.8 mJ/dot at 0.03 mJ/d.
The light reflection density of the printed dye transfer image was measured using Reflection Density 81 (manufactured by Konishiroku Photo Industry Co., Ltd.). Graph 4- shows the applied energy necessary to obtain a dye transfer image of 0.9 times the maximum optical reflection density.
This was determined as transfer sensitivity.

Book 2 Various kanji were printed on plain paper with Beck smoothness of 200 seconds, and stains other than the printed areas were observed using a magnifying glass. O
A three-step method was used: a mark shows no cracking at all, an O mark shows slight cracking, and an X mark shows significant staining.

I3 If the outside of the printing part is dirty by rubbing it 5 times with a plastic eraser using normal force, mark it with @.
A three-step method was used: if the printing was legible but the outside of the printing part was also dirty to the same extent as the printing part, it would be marked O, and if the printing part was extremely dirty and sometimes the printing could not be read, it would be marked X.

Yo4 Beck smoothness 200sec? A checkered pattern was printed on three copies of paper and observed with a magnifying glass. A three-step method was used: ■ marks indicate sharp edges of the print, ○ marks indicate slight distortion of the edges, and X marks indicate defects and blurring of the print.

As is clear from Table 1, the samples of the present invention can be printed with low energy and do not cause background stains (fogging) on paper that passes through the surface.
It can be seen that the occurrence of this phenomenon can be suppressed, and that a dye transfer image with high resolution and good fixability can be obtained. Especially sample (A)
, (B) and (C), it can be seen that better results can be obtained by combining hard wax and soft wax.

Patent applicant: Konishiroku Photo Industry Co., Ltd. Representative Patent Attorney Nobuaki Sakaguchi (1 other person)

Claims (3)

[Claims] (1) A thermal transfer recording medium having a coloring material layer containing a heat-melting substance on a support, wherein the coloring material layer contains 1,2-polybutadiene. (2) The thermal transfer recording medium according to claim 1, wherein the coloring material layer contains wax. (3) The wax is at least 1M hard wax! and at least one kind of soft wax.