JPS6161888A - Pressure-sensitive transfer material - Google Patents

Abstract

PURPOSE:To provide excellent transfer performance such as sharpness, enable a transferred image to be corrected as required and prevent oil blur from being left on correction, by using oleyl oleate as a plasticizer for a synthetic resin binder substance which is hard at normal temperature. CONSTITUTION:A pressure-sensitive transferable image forming layer comprising a synthetic resin binder substance hard at normal temperature, a plasticizer for the binder substance and a coloring agent is provided on a flexible plastic film base. In this case, the plasticizer is oleyl oleate. As the binder substance, any of synthetic resins which are hard at normal temperature and can be softened or weakened by oleyl oleate may be used singly or in combination. The film base may be any of various flexible plastic films. A transfer composition comprising the synthetic resin, oleyl oleate, the coloring agent and an appropriate amount of a solvent or the like is prepared, and is applied to the base to produce the objective transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION (+) Technical Field The present invention relates to a so-called pressure-sensitive transfer material such as pressure-sensitive Ingripon.

More specifically, for example, a pressure-sensitive ink ribbon such as a so-called correctable ink ribbon (collector pull ink ribbon),
The present invention relates to a pressure-sensitive transfer material having an improved image forming layer so as to exhibit excellent transfer performance.

(2) Prior art This type of technology will be mainly described below with reference to collector ink ribbons, but the present invention may also be applied to ordinary ink ribbons and other pressure-sensitive transfer materials that do not take post-transfer correction into consideration. Needless to say.

Collectible ink ribbons were developed to make it easier to correct typos.

Typewriters that use such ink ribbons use correction adhesive ribbons and tapes that are separate from the ink ribbons, and overprint erroneously recorded transferred images with these correction adhesive ribbons or tapes. The recording is corrected by removing it from a recording medium such as type paper and striking the removed portion with an 11-degree ink ribbon.

Such collector ink ribbons are used in an environment where transfer, correction and re-transfer of transferred images are carried out as necessary, so erroneously recorded transferred images cannot be removed using adhesive ribbon or tape for correction. Not only must it be easily removable, but it must also meet the following criteria:

In other words, (1) the image forming layer is completely peeled off from the base material in the form of an image by the image forming pressure during transfer, and is completely transferred in the form of that image onto the recording medium; (2) the transferred image is removed from the recording medium during correction; When the image-forming layer is peeled off, no oil smear or the like, which would be a trace of the transferred image, should be left on the recording medium, and (2) the image-forming layer should not fall off from the base material during the storage period.

The general structure of such an ink ribbon is to provide an image forming layer on a film base material, which is made of a transfer composition consisting of a synthetic resin binder material, an oily substance as a plasticizer for the binder material, a colorant, etc. It is usually considered that

As the plasticizer in the transfer composition, vegetable oils such as truth oil and rapeseed oil are generally used.
It is added to the transfer composition mainly for the purpose of imparting flexibility to the image-forming layer so that the image-forming layer has pressure-sensitive transferability.

Therefore, these plasticizers have the function of weakening the resin binder substance, and in order to perform good transfer, they must have a stronger affinity for the recording medium to be transferred than the film base material, and that The quality of the recording medium must be such that no oil smear is left on the recording medium during correction.

However, mineral oils such as liquid paraffin, spindle oil, or motor oil, which are commonly used as such plasticizers, do not remove the transferred image from the recording medium during correction. ′
When the recording medium is separated from the recording medium, there are disadvantages such as oil smear remaining on the recording medium as a trace of the transferred image, and part of the image forming layer falling off from the film base material during storage.

In addition, semi-drying vegetable oils such as cottonseed oil and rapeseed oil, and non-drying oils such as castor oil have strong film-forming properties, making it difficult to completely remove them from the film base material when transferred. Yes, some type of gelling agent is required to facilitate peeling. However, although it is possible to facilitate peeling from the film substrate by using a gelling agent, the gelation of these oily substances impairs the flexibility of the transfer composition and its affinity for the recording medium, resulting in the loss of the transferred image. This causes inconveniences such as loss of sharpness.

(3) Disclosure of the Invention The present invention has been made in view of the above-mentioned points. 1. The main object of the present invention is to provide a new transfer material that solves the problems of the conventional transfer materials mentioned above. It is in.

In the present invention, the above-mentioned rapeseed oil, etc. is a mixture of various fatty acids, and the use of esters of these fatty acids, especially oleyl oleate, as a plasticizer allows the image forming layer to be shaped into an image by the image forming pressure during transfer. to completely peel it off from the base material and transfer it completely in the form of an image onto the recording medium; ■When the transferred image is peeled off from the recording medium during correction, it leaves traces of the transferred image on the recording medium. This is based on the discovery that it is extremely effective in preventing oil smudges from remaining, and (2) preventing the image forming layer from falling off from the base material during storage.

That is, the present invention comprises a pressure-sensitive transferable image forming layer containing a synthetic resin binder material that is hard at room temperature, a plasticizer for the binder material, and a coloring agent, on a flexible plastic film base layer. This is a pressure-sensitive transfer material characterized in that the plasticizer is oleyl oleate.

Although the mechanism of action of oleyl oleate as a plasticizer is not clear, the transferred image in the transfer material of the present invention is sharp, and it has moderate adhesion to the recording medium and moderate peelability from the recording medium during correction. Furthermore, the number of carbon atoms in oleyl oleate is low enough that it does not leave traces such as oil smudges on the recording medium or cause problems such as falling off from the base material of the image forming layer during storage. 36, and is chemically stable without causing hydrolysis, etc., which is considered to be one of the reasons why the transfer material of the present invention has the above-mentioned excellent properties.

(4) Embodiments of the invention The resin binder material used in the present invention includes:

Synthetic resins such as polyamide resins, acrylic resins, vinyl resins, and ketone resins that are hard at room temperature and can be softened or made brittle by oleyl oleate are listed as preferred examples, and these can be used alone. or a mixture of two or more. Among these resins, thermoplastic polyamide resins are particularly preferred because they are soluble in solvents such as alcohol and toluene and have excellent economic efficiency.

As the coloring agent in the present invention, various pigments, dyes, etc. can be selected or mixed depending on the properties of the intended transfer composition, and specifically, for example, Examples include carbon black, magnetic iron oxide, Ichisaka's toned pigments, and alkali blue.

As the film base material in the present invention, various plastic films that can be used include flexible polyolefin films such as polyethylene and polypropylene, polyester films such as polyethylene terephthalate, and mixed films of these plastics.

Among them, polyethylene film has excellent flexibility, so it can come into almost complete contact with the recording surface of the recording medium during the transfer process, and can form a highly clear transferred image. These are listed as preferred. These film base materials may be colored with the above-mentioned pigments or the like as desired. The thickness of the film base material is preferably 5 to 25 ul, more preferably 12 to 18 scales.

The transfer material of the present invention can be prepared using, for example, a well-known method.

The transfer composition is prepared by preparing a transfer composition consisting of the above synthetic resin, oleyl oleate as a plasticizer for the resin, a coloring agent, an appropriate amount of a solvent, etc., and applying this onto the above substrate. The coating amount of the image forming layer on the base material is preferably within a range that does not deteriorate the flexibility of the film base material,
It is preferably in the range of 5 to 4.0 g/rn'.

(5) Examples The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to these embodiments.

[Example] Table 1 Polyamide resin and isopropyl alcohol were mixed,
The resin was heated and melted until it was dissolved. The resulting solution was placed in a sand mill, and oleyl oleate and carbon black were further mixed therein and ground until a homogeneous composition was formed to obtain the compositions shown in Table 1.

The composition was coated directly onto a 15μ thick polyethylene film substrate, the solvent in the composition was evaporated until the composition was dry, and a pressure sensitive transfer having an imaging layer with a coating weight of 3 g/rn' was carried out. I got the material.

The transfer material exhibited very good adhesion to the substrate, with no shedding of the imaging layer from the film substrate, even after standing for a long period of time (approximately 12 months). Furthermore, when this transfer material is used as an ink ribbon in a typewriter, only the portion of the image forming layer to be transferred is completely peeled off from the film base material.
The peeled portion is completely transferred onto the recording medium, and
A sharp and excellent transferred image was formed on the recording medium at 8i. Furthermore, the transferred images on these recording media did not leave any oil smear that would be traces of the transferred images on the recording medium during the correction process.

Such excellent transfer performance remained unchanged even when the transfer material was used immediately after preparation or when it was stored for a long period of time before use.

[Comparative Example 1] A pressure-sensitive transfer material was obtained in the same manner as in Example except that butyl stearate was used instead of oleyl oleate. When this transfer material was evaluated in the same manner as in the example, it was found that there were no problems with long-term storage, that is, with respect to storage stability, as with oleyl oleate, but when this transfer material was used in a typewriter, Even immediately after preparation, problems such as a portion of the image forming layer remaining on the substrate and loss of sharpness of the transferred image occurred. Furthermore, even during correction, oil smudges were left on the recording medium, and the transfer performance was not even close to that of the examples.

Butyl stearate is a fatty acid ester like oleyl oleate, but as mentioned in Comparative Example 1 above, a portion of the image forming layer may remain on the substrate, which may cause smeared prints or reduce the sharpness of the transferred image. This caused a problem in which the image quality was impaired. In addition, there is a lot of oil smearing, especially during corrections, and this oil smearing is caused by pigment (carbon black in this case) being dispersed in the oil, so the traces of the typos removed are clearly visible. Due to the smearing, typographical errors could not be completely corrected.

However, in the present invention in which oleyl oleate is used as a plasticizer, all of the runner-up problems caused by using butyl stearate can be eliminated. In other words, the printed image was very sharp, and no missing print occurred. In addition, there was no oil smear, and after the typo was corrected, it was in excellent condition with no traces of erasure.

[Comparative example 2] The oleyl oleate of the example was used as rapeseed oil.

The compositions shown in Table 2 were obtained using the same ingredients and method as in the examples except for using zinc stearate as a gelling agent for this rapeseed oil.

By spreading this composition on the same substrate as in the example, a pressure-sensitive transfer material having an image forming layer with the same coating amount as in the example was obtained.

In the case of this comparative example as well, like oleyl oleate, the image forming layer did not fall off from the base material even after being left for a long period of time, but since rapeseed oil has weak plasticity and strong film-forming properties, image formation during transfer In order to transfer the image well onto the recording medium by pressure, a gelling agent is required to alleviate the film-forming property.In the comparative example, zinc stearate was used from the viewpoint of effectiveness and economy. However, this composition also had the same drawbacks as described in Comparative Example 1.

Table 2 shows that the occurrence of printing defects and the loss of the sharpness of the transferred image were particularly noticeable due to the influence of the use of a gelling agent.

In contrast, with the present invention, which uses rail oleate as a plasticizer, there is no printing, the sharpness of the transferred image is maintained, there is no oil bleed during correction, and the ink ribbon can be stored for a long time. It was a completely new transfer material that was durable and practical.

(6) Effects of the Invention As explained above, the present invention not only provides excellent transfer performance such as sharpness, but also makes it possible to correct the transferred image as necessary. It has now become possible to provide a new transfer material that solves the problem of.

Claims (2)

[Claims] (1) A pressure-sensitive transferable image forming layer containing a synthetic resin binder material that is hard at room temperature, a plasticizer for the binder material, and a coloring agent is provided on a flexible plastic film base material, and the plasticizer is A pressure-sensitive transfer material characterized in that is oleyl oleate. (2) The transfer material according to claim 1, wherein the binder material is a polyamide resin.