JPH0725229B2 - Transfer material for printer - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a transfer material for printers,
More specifically, it relates to an ink transfer material having excellent dimensional stability and durability used in a typewriter or a thermal printer.

[0002]

2. Description of the Related Art A polyester film is used as the base of a transfer material for a printer because of its high crystallinity, high melting point, heat resistance,
It is used because it has excellent properties such as chemical resistance, strength, and elastic modulus.

This transfer material withstands the tension and printing pressure applied to the transfer ribbon in the dot impact method of typewriters and printers and is durable enough to be used repeatedly. Since thin products are sought, they are required to have high strength as well as small deformation such as shrinkage due to heat.

[0004]

However, a transfer material using an ordinary biaxially oriented polyester film as a base film is liable to cause film elongation during transfer and plastic strain of the film due to unstruck residuals in a printing portion. However, it was unsatisfactory for transfer ribbons with high tension and printing pressure.

On the other hand, as the base film, the longitudinal F
When a normal toughening polyester film having a 5 value of more than 16 kg / mm ² is used, longitudinal tearing of the film is likely to occur during transfer, and thermal contraction is too large for heat-sensitive transfer, so There was a defect that it could not be used.

The present invention is intended to provide a transfer material for a printer which does not have the above-mentioned drawbacks, that is, has excellent dimensional stability and durability.

[0007]

The present invention has a thickness of 6.0.
μm, vertical F5 value is 10.2 kg / mm ² , lateral F5 value is 10.5 kg / mm ² , vertical refractive index is 1.6471, horizontal refractive index is 1.6730,
A printer in which a transfer ink layer is provided on one surface of a biaxially oriented polyester film having a rough surface on at least one side and a center line average roughness of the rough surface of 0.16 μm and a maximum height of the rough surface of 1.15 μm. It is characterized by a transfer material for use.

The polyester referred to in the present invention is a well-known polyester, preferably polyethylene terephthalate, a copolymerized polyester having an ethylene terephthalate unit as a main repeating constitutional unit, or a polymer blend containing such a polyester as a main component. It is a polymer selected from the group consisting of: In the copolymerized polyester, the terephthalic acid component accounts for 80 mol% or more of the acid component of the polyester, and 80 mol% of the glycol component.
The ethylene glycol component occupies the above, and the polymer blend preferably has the above polyester occupying 80% by weight or more and the other polymer occupying 20% by weight or less. Further, the polyester used in the present invention, if necessary, a stabilizer, a colorant, an antioxidant, a lubricant,
Other additives may be contained.

The polyester film used in the present invention is
The composition comprising the polyester is biaxially oriented, and the F5 value in the machine direction of the film is 10.2 kg / m.
It is those of m ^2. If the F5 value is less than 10.2 kg / mm ^2, it is easy to stretch and the elastic recovery is difficult to occur, so that plastic strain in the printed portion causes unpleasant winding, which is not preferable. Also, 10.
If it exceeds ² kg / mm ² , the rigidity is high and the film is likely to tear due to the printing pressure, which is not preferable.

The refractive index of the film is 1.6471 in the longitudinal direction and 1.6 in the lateral direction.
It must be 730.

The polyester film of the present invention must have a thickness of 6.0 μm. If it is thicker than the above, it takes time to transfer heat, which is not suitable for high speed recording.
On the contrary, if it is thinner than the above, the strength is low and the workability is poor, which is not preferable.

At least one surface of the polyester film of the present invention is rough, and the roughness of the surface is 0.16 μm in center line average roughness and 1.15 μm in maximum height. If it is smaller than the above range, the slipperiness is deteriorated, wrinkles are formed in the film, troubles during processing, and sticking of the thermal head portion occur, which is not preferable.
If it exceeds the above range, the image quality is not clear, the sensitivity is lowered, and the thermal head is worn, which is a practical problem. The above roughness is generally known such as the addition of inorganic particles, organic particles, etc. in the film, the composite of the roughened film, the crystallization acceleration of the film after melt extrusion, the sand mat method, the chemical treatment method, the coating mat and the like. It can be obtained by applying the appropriate method. Particularly for forming a rough surface, it is preferable to add 0.05 to 5% by weight of inorganic particles having an average particle diameter of 0.02 to 20 μ.

Next, a method of manufacturing the transfer material of the present invention will be described.

First, polyester is melted, extruded in a sheet form from a slit die, and cooled and solidified by a casting drum to form an unstretched sheet, and the sheet is longitudinally stretched, that is, a plurality of one or more sheets. 80-1 in the section
After heating to 30 ° C. and stretching such that the total magnification becomes 3.0 to 7.0 times due to the difference in peripheral speed between the rolls, 9
Horizontal stretching at 0 to 120 ° C. and 3.0 to 4.0 times, then 2
Heat treatment is performed at 00 to 230 ° C. to obtain a biaxially oriented polyester film. In addition, following the above-mentioned transverse stretching, re-longitudinal stretching at a stretching temperature of 95 to 110 ° C. and a stretching ratio of 1.05 times or less may be performed, and heat treatment may be performed to obtain a biaxially oriented polyester film.

Orientation in the longitudinal direction produced by the longitudinal-transverse-longitudinal three-stage stretching method described in Japanese Patent Publication No. 34-5887 and the lateral-longitudinal stretching method described in Japanese Patent Publication No. 37-1588. A so-called toughened polyester film having an increased degree is not preferable because the F5 value in the longitudinal direction exceeds 16 kg / mm ² and the refractive index in the lateral direction is less than 1.650.

Next, a transfer ink layer is formed on the biaxially oriented polyester film of the present invention obtained as described above. The biaxially oriented polyester film may be subjected to a pretreatment such as a corona discharge treatment or an undercoat, if necessary.

The transfer ink of the present invention is not particularly limited, and known ones can be used. Specifically, a binder component, a coloring component, and the like are main components, and if necessary, a softening agent, a flexible agent, a melting point adjusting agent, a smoothing agent, a dispersant, and the like are used as additive components. In short, it is constructed by appropriately selecting and combining known materials.

As specific examples of the main components, well-known waxes such as paraffin wax, carnauba wax, ester wax and various low melting point polymers are useful as the binder component, and as the colorant component, Carbon black and various organic and inorganic pigments or dyes are useful. Further, the ink includes sublimation type ink.

As a method for providing the transfer ink layer on one side of the film of the present invention, a well-known method, for example, hot melt coating, solution coating method such as gravure, reverse or slit die method with a solvent added is used. Can be used.

When the transfer material is used for thermal transfer, a fusion preventing layer may be provided on the side of the film where the transfer ink layer is not provided in order to prevent sticking of the thermal head portion.

[0021]

[Characteristic Measuring Method and Evaluation Criteria] The characteristic value measuring method defined in the present invention will be described below.

(1) F-5 value Set on a Tensilon type tensile tester according to ASTM-D-882 so as to have a test width of 10 mm and a test length of 100 mm,
Tensile speed 200mm / min, temperature 20 ℃, humidity 65% R
The corresponding strength at 5% elongation of the film at H condition was measured.

(2) Refractive Index An analyzer is attached to the Abbe refractometer, and the NaD line is used to measure the refractive index in both the vertical and horizontal directions at room temperature and normal humidity (20 ± 2 ° C., 65% RH). (The measurement principle is
Volume 8 of Applied Polymer Science
717 (1964)).

(3) Surface Roughness According to JIS-B-0601.

[0025]

EXAMPLES The embodiments of the present invention will be described below based on examples. However, "parts" represent parts by weight.

Example 1 Calcium carbonate 0.2 having an intrinsic viscosity of 0.61 and an average particle diameter of 3.0 μm measured by melting o-chlorophenol at 35 ° C.
Polyethylene terephthalate containing wt% was melt-extruded into a sheet shape with an extruder and a T-die, brought into close contact with a water-cooling drum and cooled and solidified to obtain an amorphous sheet having a thickness of 70 to 120 μm. This sheet was longitudinally stretched at 95 ° C. and 3.6 times,
The film was transversely stretched at 110 ° C. and 3.2 times, and then heat treated at 225 ° C. to obtain a normal sequential biaxially stretched polyester film.

The above film characteristics were measured, and the results are shown in Table 1.

[0028]

[Table 1] Next, a 2 μm layer made of a methylmethacrylate and a butylacrylate copolymer was provided as an impact transfer ink layer on the surface of the polyester film, and then a vinyl chloride-vinyl acetate copolymer (87% / 13%):
10 parts Lanolin: 6 parts Vegetable oil: 4 parts Carbon black: 5 parts Toluene: 25 parts Methyl ethyl ketone: 50 parts A layer consisting of 50 parts was applied and dried so that the solid component thickness would be 10 μm.

As a thermal transfer ink layer on the surface of the polyester film, a transfer ink layer comprising carnauba wax: 30 parts, ester wax: 35 parts, carbon black: 12 parts, polytetrahydrofuran: 10 parts, silicone oil: 3 parts, A transfer material was obtained by applying the hot-melt coating method using a heating roll to a thickness of 5 μm.

Using the obtained transfer material, a print test was conducted with a dot impact type printer and a thermal transfer type printer.

The transfer material used as the base material of the present invention, that is, Example 1, gave a very good image quality.

Comparative Example 1 One side of a biaxially oriented polyester film having a thickness of 8 μm obtained in the same manner as in Example 1 was roughened by sand mat processing, and the same heat-sensitive transfer ink layer as in Example 1 was provided on the opposite side. A transfer material was formed. The center line average roughness of the matte surface is
The height was 1.1 μm and the maximum height was 12.5 μm. When the film was printed by a thermal transfer printer, the ink was not transferred uniformly and the image was unclear.

[0033]

According to the present invention, since a transfer ink layer is provided on a specific polyester film, when used for impact, there is no vertical tear due to printing, plastic strain such as unstruck residue is small, and durability is excellent. It was possible to obtain the effect of being present.

Further, when used as an ink film for a thermal printer, it is possible to obtain an effect that the thickness can be made thinner than a normal polyester film, and that the shrinkage due to heat is smaller than that when using a reinforced polyester film.

Further, since the base film of the present invention has a specific surface roughness, it does not stick to the thermal head, has good running properties in the printer, and has good spooling properties. Excellent print image clarity.

In particular, the transfer material of the present invention can be put in a case such as a cassette, and has excellent characteristics for miniaturization. Therefore, it is extremely useful as a small cassette type transfer material.

Claims (1)

[Claims] 1. A thickness of 6.0 μm and a longitudinal F5 value of 1.
0.2 kg / mm ² , lateral F5 value is 10.5 kg /
mm ² , the vertical direction refractive index is 1.6471, the horizontal direction refractive index is 1.6730, and at least one surface is rough and the center line average roughness of the rough surface is 0.16 μm. A transfer material for a printer, comprising a biaxially oriented polyester film having a maximum height of 1.15 μm and a transfer ink layer provided on one surface thereof.