JPS61143179A - Pressure-sensitive transfer material - Google Patents

Abstract

PURPOSE:To enhance suitability to pressure-sensitive transfer and correctability, by providing an ink layer with a specified composition on a flexible plastic film base. CONSTITUTION:The pressure-sensitive transfer material comprises on the flexible plastic film base a pressure-sensitive transferable ink layer comprising a binder resin, a plasticizer for the binder resin and a coloring agent, the plasticizer being constituted of liquid paraffin and oleyl oleate, both of which are chemically stable and function as a plasticizer. As the binder resin, at least one synthetic resin such as a polyamide resin, an acrylic resin, a vinyl resin and a ketone resin is used either singly or in combination. Among these resins, particularly preferred is a thermoplastic polyamide resin, which is soluble in solvents such as alcohol and toluene and is inexpensively available.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to so-called pressure-sensitive transfer materials such as pressure-sensitive ink ribbons.

More specifically, the present invention relates to a so-called correctable (collectible) ink ribbon or pressure-sensitive transfer material that has improved pressure-sensitive transfer suitability and correction suitability by improving the ink layer.

A collector-pull ink ribbon has been developed to make it easier to correct typographical errors. Such collector ink ribbons generally have a pressure-sensitive transferable ink layer formed on a film base material. In addition, typewriters that use such collector ink ribbons use an adhesive ribbon or tape for correction that is separate from the ink ribbon. The recording is corrected by removing the ink from the recording medium such as type paper by overprinting and again transferring the correct ink image onto the removed portion using an ink ribbon.

Such collector ink ribbons are subjected to processes such as transfer, correction of the transferred image as necessary, and retransfer, so erroneously recorded transferred images can be easily corrected with adhesive ribbon or tape. In addition to being removable, it is also necessary to satisfy the following characteristics.

That is, (1) the ink layer is completely peeled off from the base material in the form of an image due to image forming pressure such as type pressure during transfer, and is completely transferred in the form of the image onto the recording medium (transferability).
(2) The erroneously recorded transferred image can be easily removed with an adhesive ribbon or tape for correction, and when the transferred image is peeled off from the recording medium during correction, there is no oil that leaves traces of the transferred image on the recording medium. (3) the ink layer does not fall off from the base material during the storage period (fastness of the ink layer), etc.

In such an ink ribbon, the transferable ink constituting the ink layer formed on the film base material is usually composed of a synthetic resin binder substance, an oily substance as a plasticizer for the binder substance, a colorant, etc. .

The plasticizer in the transfer ink is generally liquid paraffin, mineral oil such as spindle oil or motor oil,
Fatty acid esters such as butyl stearate are used, and such plasticizers are added mainly for the purpose of imparting flexibility to the ink layer and imparting pressure-sensitive transferability to the ink layer. Therefore, these plasticizers have the function of weakening the resin binder substance, and in order to enable good transfer, they must have a stronger affinity for the recording medium than the film base material, and that must be such that no oil smear is left on the recording medium during correction.

However, when mineral oil such as the above-mentioned liquid paraffin, which is generally widely used, is used as a plasticizer, a transfer failure phenomenon occurs in which the transfer is not completely transferred onto the recording medium during transfer at low temperatures (for example, 10°C). or cause
When the transferred ink image is peeled off from the recording medium during correction, there are drawbacks such as oil smudges remaining as traces of the transferred image on the recording medium.

Furthermore, when a fatty acid ester such as butyl stearate is used as a plasticizer, there are disadvantages such as oil smearing as traces of the transferred image on the recording medium when the transferred image is peeled off from the recording medium during correction.

Foresight 11 The main object of the present invention is to provide a transfer material that solves the problems of the conventional transfer materials mentioned above.

A more specific object of the present invention is to provide a modifiable pressure-sensitive transfer material that has improved pressure-sensitive transfer suitability and modifyability by improving the ink layer.

According to the research of the present inventor, by using a mixed system of liquid paraffin and oleyl oleate as a plasticizer, good pressure-sensitive transferability and good correction aptitude can be achieved not only at room temperature but also at low temperatures. It has been found that a pressure-sensitive transferable ink layer having good fastness can be obtained.

The pressure-sensitive transfer material of the present invention is based on such knowledge, and more specifically, a pressure-sensitive transferable ink layer containing a binder resin, a plasticizer for the binder resin, and a colorant is combined with a flexible material. It is provided on a plastic film base material, and is characterized in that the plasticizer consists of liquid paraffin and oleyl oleate.

Both liquid paraffin and oleyl oleate are chemically stable and each acts as a plasticizer. It is not clear why the above-mentioned excellent pressure-sensitive transferable ink layer can be obtained by using a mixed plasticizer of liquid paraffin and oleyl oleate. It is inferred that at least the fact that the film properties of the ink layer are stabilized over the temperature range and the adhesion to the substrate and the recording medium are made homogeneous is at least an effective contributing factor.

The present invention will be explained in more detail below. In the following description, "%" and "part" expressing quantitative ratios are based on weight, unless otherwise specified.

1. The film base material constituting the pressure-sensitive transfer material of the present invention includes:
Films made of various plastics such as flexible polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, or mixtures of these plastics can be used. Even in terms of width, polyethylene film has excellent flexibility, and because of this, it can come into almost complete contact with the recording surface of the recording medium during the pressure transfer process, making it possible to form a highly clear transferred image. , particularly preferred. These film base materials may be colored with pigments as described below, if necessary. The thickness of the film base material is 5 to 251 Lm, especially 12 to 18 Lm.
Preferably it is 1 Lm.

The pressure-sensitive transfer material of the present invention has the following properties:
It is obtained by forming a pressure-sensitive transferable ink layer containing a binder resin, a plasticizer for the binder resin, and a colorant.

The binder resin is solid at room temperature and can be softened or weakened by the plasticizers of the present invention, such as liquid paraffin and oleyl oleate.
Synthetic resins such as polyamide resin, acrylic resin, vinyl resin, and ketone resin can be used, and these resins may be used alone or in combination of two or more. Among these resins, particularly preferred are thermoplastic polyamide resins which are soluble in solvents such as alcohol and toluene and are economically superior. Among them, those produced by the reaction of dimer acid and di- or poly-amine and have a molecular weight of about 3000 to
A polyamide having an amine value of about 17,000, particularly about 5,000 to about 10,000, and an amine value of 10 or less, particularly 1 to 5, is preferably used.

According to the invention, plasticizers consisting of liquid paraffin and oleyl oleate are used in combination with these binder resins.

Liquid paraffin technically belongs to the lubricating oil fraction and is a liquid saturated hydrocarbon with high purity, but for the purposes of the present invention, liquid paraffin has a specific gravity of 0.835 to 0.886 (15/4°C). ,
Especially 0.851-0.876, viscosity RW (30℃) 4
3 to 505, particularly 120 to 315 are preferably used.

These plasticizers are preferably used in a total amount of 0.4 to 2.0 parts, particularly preferably 1 part to 1.6 parts, per 1 part of the polyamide resin.

If the amount is less than 0.4 part, the transferability will be deteriorated, and if it is used in excess of 2 parts, set-off will easily occur during preparation or storage of the transfer material.

Furthermore, the ratio of liquid paraffin to oleyl oleate is such that oleyl oleate is used in a range of 0.2 to 6.0 parts, particularly 0.4 to 1.5 parts per part of liquid paraffin. is preferred.

If the amount of oleyl oleate is less than 0.2 parts, the effect of improving low-temperature transferability or oil smear after peeling off the transferred image will be insufficient when using liquid paraffin alone, and if the amount of oleyl oleate is less than 6 parts, If it is used in excess of this temperature, images formed at high temperatures (for example, 30° C.) will become slightly thick.

Furthermore, as the coloring agent used together with the binder resin and plasticizer described above, various pigments or dyes are appropriately selected depending on the required color tone, etc., and are used in an amount depending on the desired concentration.

Specifically, for example, carbon black, magnetic iron oxide, alkali blue, and other commercially available toned pigments are used.

The pressure-sensitive transfer material of the present invention comprises a binder resin, a plasticizer made of liquid paraffin and oleyl oleate, and other additives such as a surfactant added as necessary. A pressure-sensitive transferable ink layer is obtained by diluting a pressure-sensitive transferable ink, usually in an appropriate amount of a solvent, and applying it onto the above-mentioned film base material and drying it.

The thickness of the pressure-sensitive transferable ink layer is preferably within a range that does not deteriorate the flexibility of the film base material, for example, 1.5
A range of 4.0 g/m2 is preferred.

As explained above, according to the present invention, in addition to the hard resin and the colorant, a plasticizer consisting of a combination of liquid paraffin and oleyl oleate is blended on the film base material. By forming a pressure-sensitive transferable ink layer, it has good transferability at room temperature and low temperature, and also eliminates problems such as oil bleeding on the recording medium during correction and falling off of the ink layer from the base material during storage. A pressure-sensitive transfer material is provided in which the above problems are solved. Although this pressure-sensitive transfer material was developed as a correctable transfer material, it can be used as a non-correctable transfer material by taking advantage of its excellent transferability.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Polyamide resin and isopropyl alcohol were mixed according to the formulations shown in Table 1 above, and heated and dissolved until the resin was dissolved. The resulting solution was placed in a sand mill, to which liquid paraffin, oleyl oleate and carbon black were further mixed and mixed until a homogeneous composition was formed to obtain the compositions shown in Table 1.

Applying the composition directly onto a polyethylene film substrate with a thickness of 15 ILm, evaporating the solvent until the coating is dry,
A pressure-sensitive transfer material was obtained having an ink layer with a thickness of about 3 g/m2.

Even after the transfer material was left for a long period of time (12 months), the ink layer did not fall off from the film base material, and its adhesion to the base material was very good. Furthermore, when this transfer material is used as an ink ribbon in a typewriter at room temperature or low temperature, only the pressure-printed portion of the ink layer is completely peeled off from the film base material and is completely transferred onto the recording medium. An extremely sharp and excellent transferred image was formed. Furthermore, when the transferred images on these recording media were removed using a correction adhesive ribbon, they were removed without leaving any traces of oil smear on the recording media.

Such excellent transfer performance did not change consistently even when the transfer material was used immediately after preparation or when it was stored for a long period of time before use.

Ratio JL Example 2 A pressure-sensitive transfer material was prepared in the same manner as in the example except that liquid paraffin corresponding to the total amount of these as shown in Table 2 was used instead of the liquid paraffin and oleyl oleate in the above example. I got it.

When this transfer material is used in a typewriter, at low temperatures (
(10° C.), a portion of the ink layer remained on the substrate, resulting in incomplete transfer. Furthermore, oil smudges were left on the recording medium during correction, and the correction suitability was clearly inferior to that of the examples.

A pressure-sensitive transfer material was prepared in the same manner as in the example except that in place of the liquid paraffin and oleyl oleate in Example 2, butyl stearate corresponding to the total amount thereof as shown in Table 3 was used. I got it.

When this transfer material is used in a typewriter.

When the transferred image was peeled off from the recording medium during correction, oil smeared on the recording medium as traces of the transferred image, making it impossible to completely remove typographical errors.

Claims (1)

[Scope of Claims] 1. A pressure-sensitive transferable ink layer containing a binder resin, a plasticizer for the binder resin, and a colorant is provided on a flexible plastic film base material, and the plasticizer is fluidized. A pressure-sensitive transfer material comprising paraffin and oleyl oleate. 2. The pressure-sensitive transfer material according to claim 1, wherein the binder resin is a polyamide resin.