JPS6116890A - Heat sensitive transfer recording material - Google Patents

Abstract

PURPOSE:To form a heat sensitive recording material having a good heat resistance property and cheap by containing a reinforcing filler in a matrix polymer of a base film. CONSTITUTION:A heat sensitive transfer material 5 comprises a heat sensitive ink layer 1, a base film 2 and a reinforcing filler 3. The reinformcing filler is metal or metallic oxide or another inorganic substance, a high molecular particle or the like, especially a bridged high molecular particle, and preferably to have an affinity with a high molecular material defining a film base, and may have a reaction activity. Further, in the case of an inorganic particle, it may be used after its surface is treated with a surface active agent and a coupling material such as silane coupling material, titanate coupling material or the like or after a surface treatment with a polymer. Especially, carbon black, silica, almina, ZnO, TiO2 particle or the like are suitable for a reinforcing filler. Thereby, this is easy to handle and can be used in various thermal printer, thermal facsimile or the like suitably without generation of sticking.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a new thermal transfer recording material.

More specifically, the present invention relates to a thermal transfer recording material which is prevented from sticking phenomenon in which a base film is fused to a head during heating and from poor film running.

[Conventional technology]

Conventionally, a thermal transfer material consisting of a base material and a heat-melting or heat-sublimating heat-sensitive ink layer provided on the top surface of the base material is used.
With the thermal ink layer and the recording paper in close contact with each other, heat pulses are selectively applied from the back side of the substrate using a heating head according to the recording signal to melt or sublimate the thermal ink layer in that area and transfer it to the recording paper. As the base material of the thermal transfer recording material used for recording, thin paper such as capacitor paper or glassine paper, or plastic film such as polyethylene terephthalate or polyelectrode is used.

When using thin paper, since it is paper, it has a softening point and a heat resistance temperature of approximately 400°C, and the sticking phenomenon does not occur, but it tends to absorb moisture from the air and wrinkle, and is difficult to use. In order to have a certain mechanical strength without any problems, it has to be thicker than the thermal ink layer, and due to the roughness of the surface that comes into contact with the heating head, which has low thermal conductivity, it cannot withstand the energy applied from the heating head. This results in low sensitivity and has a negative effect on the transferred image on the recording paper. Further, when a plastic film is used, there are drawbacks such as sticking occurs with a film made of polyethylene terephthalate or the like, and heat-resistant films such as polyimide are extremely expensive.

In order to overcome the drawbacks of these conventionally used base materials,
For example, attempts have been made to improve the polyethylene terephthalate by providing a metal vapor-deposited layer and various other heat-resistant protective layers on the back surface, but this complicates the manufacturing process, increases manufacturing costs, and results in a thicker base material, which reduces recording sensitivity and transferred images. New drawbacks have arisen, such as adversely affecting image quality.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to solve the above-mentioned problems and provide a heat-sensitive recording material that has good heat resistance and is inexpensive.

A further object of the present invention is to provide a heat-sensitive recording material with high sensitivity and high image quality.

[Means and effects for solving the problem] 31 The inventors of the present invention have conducted intensive studies and have developed a thermal transfer film consisting of a base film and a thermal ink layer having heat-melting properties, heat-sublimation properties, etc. provided on the upper surface of the film. Metals, metal oxides,
When the base film is reinforced and made difficult to melt by containing reinforcing fillers such as inorganic substances and polymer particles, a part of the base film is heated by applying heat pulses, flash light, laser light, etc. from a heating head. They have discovered that it is possible to realize a thermal transfer material that is highly sensitive and does not impair the quality of transferred images by preventing the sticking phenomenon in which the film melts and adheres to the heating head, and also prevents poor film running. The present invention has now been completed.

Next, the thermal transfer material of the present invention will be explained using the drawings.

As shown in FIG. 1, the thermal transfer material 5 of the present invention comprises a thermal ink layer 1, a base film 2, and a reinforcing filler 3.

The reinforcing filler used in the present invention is preferably a metal, a metal oxide or other inorganic material, a polymer particle, especially a crosslinked polymer particle, etc., and preferably has an affinity with the polymer material constituting the base film, and is also reactive. It may have activity. In the case of inorganic particles, the particles may be used after their surfaces are treated with a coupling agent such as a surfactant, a silane coupling agent, or a titanate coupling agent, or after surface treatment with a polymer. Especially carbon black, silica, alumina, and ZnO.

T101 particles and the like are suitable as reinforcing fillers.

These may be used not only alone, but also as a mixture of two or more. In addition, the particle size of the reinforcing filler is 1μ
m or less, particularly about 10#Iμm to 100mm. The shape does not necessarily have to be spherical, but may be needle-like, plate-like, or other regular shapes.

If the particles have shape anisotropy, 1. These particles may be oriented and dispersed by mechanical, electrical, magnetic treatment, etc., if necessary. The filler content in the base film ranges from 3 to 65 volumes, preferably from 10 to 40 volumes.

Although the exact mechanism by which sticking of the thermal transfer material is prevented by incorporating the reinforcing filler into the base film is not clear, for example, in the case of polyethylene phthalate film, its crystal melting point is about 263°C;
Normally, if it were a perfect crystal, the base film would not melt due to the heat pulse with a maximum bulk temperature of about 200°C applied by the heating head during recording, and sticking would not occur, but in reality, sticking does not occur. Ori,
This is thought to be due to melting of the amorphous portion in the polyethylene terephthalate film used as the base film.

According to the present invention, the amorphous portion is thermally and mechanically reinforced by incorporating a reinforcing filler into the matrix polymer, thereby making the base film refractory and preventing and improving the occurrence of sticking. In addition, such reinforcing fillers often have higher thermal conductivity than matrix polymers, which improves the thermal conductivity of the base film and increases recording sensitivity and increases the thermal conductivity of the base film without making the base film unnecessarily thin. It also has the effect of improving image quality. In addition, the surface properties of the base film are improved geometrically (for example, by forming appropriate irregularities on the base film surface) and electrically (for example, antistatic) to stabilize running properties and improve heat-sensitive properties. It was confirmed that this also contributed to improving the adhesion between the ink layer and the base film.

The matrix polymer 4 used in the present invention is a conventionally known base film-forming through matrix polymer, and is not particularly limited.
Examples include polyester, triacetylcellulose, nylon, and polycarbonate. The base film 2 is prepared by mixing and melting a composition consisting of the matrix polymer 4 and the above-mentioned reinforcing filler 3, or dissolving and dispersing it in an appropriate solvent, and troweling the mixture into a film shape using a predetermined method. During or after film formation, it is subjected to stretching and orientation treatment as necessary, and heat treatment if necessary, and is preferably used at a thickness of 0.5 μm to 100 μm, preferably 3 μm to 30 μm. Ru. In addition to the reinforcing filler, a thermal conductivity control agent, a charge control or prevention agent, a mold release agent, etc. may be added to the matrix polymer as necessary.

The heat-sensitive ink layer 1 is a heat-sensitive ink layer that is heat-meltable, heat-sublimable, etc., and is not particularly limited. Formed by hot melt coating or solvent coating)
, or formed into a film with a base film 2 and formed with a thickness of 0.5 μm to 20 μm.
μm1 Preferably the layer is 1 μm to 10 μm. Further, if necessary, an intermediate layer may be provided between the ink layer 1 and the paste layer 2 to adjust the adhesive strength between the two.

The heat-sensitive recording material of the present invention will be explained below with reference to Examples and Comparative Examples.

Comparative Example An ink composition consisting of 25 parts by weight of carbon black, 25 parts by weight of carnauba wax, 40 parts by weight of ester wax, 20 parts by weight, and 15 parts by weight of spindle oil was mixed, melted, and applied to a thickness of approximately 5 μm on a polyethylene terephthalate film I having a thickness of 9 μm. This was used as a thermal transfer recording material.

Using an 8-dot/Fuo thick-film thermal head (average resistance 200Ω), apply a power of 2W/dot, pressure of 0.7 kg, and a heat pulse from the back side of the base film under the printing conditions of "i". When the heat pulse was applied with a pulse width of 0.1 m·sec to 5 m·sec, sticking occurred due to the application of the heat pulse of about 0.5 m·sec, and recording was completely impossible.

Example 1 A resin composition consisting of 20 parts by weight of carbon black (average particle size d = 24 μm) and 80 parts by weight of polyethylene terephthalate was melted and mixed in an extruder, extruded in a T-die, and then subjected to biaxial stretching and orientation treatment. and thickness 11
A μm base film was obtained. This was coated with the same ink as in the comparative example to a thickness of about 5 μm to obtain a thermal transfer recording material.

Using an 8 dot/R thick film thermal head (average resistance 200 Ω), a heat pulse was applied from the back side of the base film under printing conditions of 2 W/dot applied power and 0.7 Kf/- pressing pressure. When applied with a pulse width of 1 m·sec to 5 m·sec, good printing was obtained and no sticking occurred during recording.

Example 2 A resin composition consisting of 25 parts by weight of hydrophobized silica (average particle size d = 16 μm) and 75 parts by weight of polyethylene terephthalate was prepared as a base film in the same manner as in Example 1, and
When this was used, no sticking occurred even when a heat pulse with an applied pulse width of 5 m/sec was applied, good printing was obtained, and no trace of melting was observed on the back surface of the base film after recording.

〔Effect of the invention〕

As explained above in detail, the thermal transfer material of the present invention contains a reinforcing filler in the base film, does not cause sticking (and is easy to handle, and can be used in various thermal printers and thermal facsimiles). ?9 etc. can be suitably used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the thermal transfer recording material of the present invention. Codes in the figure: 1...Thermal ink layer; 2...Base film layer; 3
... Reinforcing filler; 4... Matrix polymer; 5
...Thermal transfer recording material. Figure 1

Claims (1)

[Claims] 1. A thermal transfer recording material comprising a base film and a thermal ink layer, characterized in that the base film contains a reinforcing filler in a matrix polymer. 2. The reinforcing filler is metal or metal oxide, silica,
The thermal transfer recording material according to claim 1, which is selected from carbon and organic polymer particles.