JP2929595B2 - Retransfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dry process for forming characters, symbols, figures, etc. on the surface of an object to be transferred by pressure-sensitive transfer of images of characters, symbols, figures, etc. The present invention relates to a retransfer sheet of a transfer material, and more particularly to a retransfer sheet of a dry transfer material produced by printing and heat transfer by a printing device such as a thermal transfer printer, a typewriter, and a word processor.

[Prior Art] A report on a basic sheet from which a dry transfer material can be manufactured by a thermal transfer method has been reported in JP-A-63-128987.

In this report, a film made of polyethylene, polypropylene, fluororesin, etc. having a smooth surface property with a contact angle to water of at least 95 °, or a coating layer made of silicone resin on the surface of paper, metal foil, or plastic film substrate Is used.

[Problems to be Solved by the Invention] In order to form an image by thermal transfer onto a sheet having a contact angle of 95 ° or more (especially 105 ° or more), the surface tension of the ink must be reduced to form the image on the sheet. After getting wet,
Since the adhesive force between the sheet and the ink must be greater than the cohesive force between the inks and the adhesive force between the ink and the polyethylene terephthalate (PET) substrate, it is necessary to increase the temperature of the ink. In order to achieve this, high printing energy is required, which is extremely disadvantageous for the thermal transfer apparatus, such as durability of the head and load on a power supply.

Further, an image formed on a surface having poor wettability by thermal transfer is re-transferred only by applying a small amount of pressure because of weak adhesion to the surface. For this reason, an unnecessary image is retransferred, which causes stain. In addition, there is also a problem that an image can be obtained with a slight touch during handling.

Further, since the static friction coefficient of the surface of the sheet is remarkably small, there is a problem that the sheet is easy to move and is difficult to fix when retransferring the thermally transferred ink image. Therefore, a complete image cannot be obtained because the retransferred image is displaced or distorted.

By the way, in order to prevent the movement of the sheet which becomes a problem at the time of pressure-sensitive retransfer, Japanese Patent Application No. 62-80127 reports that an adhesive layer is provided on a sheet separately from a transfer pattern. .

However, providing the pressure-sensitive adhesive layer partially at a predetermined position requires a device for manufacturing and requires a dedicated device, resulting in a large cost. Also, to cover the adhesive surface until use,
It is necessary to attach release paper and the like, and furthermore, a device and cost are required. In addition, in the case of a sheet provided with a peelable coating layer made of a silicone resin, it is necessary to apply two types of coating layers and an adhesive layer. There is a good chance that it will affect you when you do. That is, if silicone is applied first, repelling will occur when the adhesive is applied.On the other hand, if the adhesive is applied first, application becomes difficult due to stickiness, and release paper must be used to prevent this stickiness. Even if it is applied, it is still difficult to apply because of its thickness. Even if it can be manufactured successfully, since the pressure-sensitive adhesive layer is only partially present, the entire area around the image is not fixed, so the sheet will still move, making it difficult to form a complete image. is there.

Accordingly, the present invention has been made in view of such circumstances, and a first object of the present invention is to provide a retransfer sheet that facilitates fixing of a sheet at the time of retransfer and is hard to move. is there.

It is a second object of the present invention to provide a retransfer sheet in which an ink image on the retransfer sheet is not peeled off by a slight pressure or rubbing.

Further, a third object of the present invention is to provide a retransfer sheet capable of obtaining good transfer quality with low transfer energy.

Furthermore, a fourth object of the present invention is to provide a retransfer sheet capable of obtaining a good retransfer quality even though the adhesive force between the ink image and the retransfer sheet is increased as compared with the conventional one. Is to do.

Further, a fifth object of the present invention is to provide a retransfer sheet capable of obtaining good retransfer quality even when a material having good wettability (contact angle to water of 80 ° or less) is used in the surface treatment composition. To provide.

Furthermore, a sixth object of the present invention is to provide a retransfer sheet having a surface treatment agent whose wettability can be adjusted so that good retransfer quality can be obtained even when the applied energy during thermal transfer is changed. Is to provide.

A seventh object of the present invention is to provide a retransfer sheet having a surface treating agent capable of easily forming a dry thin film by drying at a low temperature for a short time.

Further, an eighth object of the present invention is to provide a retransfer sheet having a surface treatment agent which can easily wash equipment used for production and application of the surface treatment agent and does not affect the other such as set-off. It is in.

Furthermore, a ninth object of the present invention is to provide a surface treatment agent that can achieve the above object without considering compatibility with other surface treatment agent compositions such as solubility and compatibility.

[Means for Solving the Problems] In order to achieve the above object, the retransfer sheet of the present invention uses an ink image thermally transferred on a base sheet by a thermal transfer method, and an ink image transfer side of the base sheet. Is a retransfer sheet of a dry transfer material for retransferring the ink image to an arbitrary receptor by applying pressure from the opposite surface, wherein the surface formed on the ink image transfer side surface of the substrate sheet The treatment agent layer has an elongation of 100% or more, and the composition of the surface treatment agent layer contains a material having a contact angle to water of 80 ° or less and polyethylene fine powder in a dispersed manner.

Here, the elongation may be realized by an ethylene-vinyl acetate copolymer contained in the composition of the surface treatment agent layer.

The elongation may be realized by polyethylene contained in the composition of the surface treatment agent layer.

More preferably, the surface treatment agent layer has a static friction coefficient of 0.25 or more and a contact angle with water of 80 to 120 °.

(Specific Configuration / Action) The retransfer sheet 10 according to the present invention is formed, for example, by forming a surface treatment agent layer 12 on one surface of a base material (base sheet) 11 as shown in FIG. By

Such a substrate 11 has a thickness of 25 to 200 μm, preferably 50 to 150 μm.
It is desirable to have a thickness of μm. And in manufacturing,
While having sufficient mechanical strength in handling, it is desirable to have a certain degree of flexibility so that pressure is easily applied at the time of pressure-sensitive retransfer and that a dry transfer agent can be easily manufactured by thermal transfer. .

However, if the stretch is too large, the substrate 11 is stretched by applying pressure during retransfer, and the ink image 13 is distorted. Therefore, a film having a stretch of 200% or less is preferable.

In addition, the substrate 11 is preferably transparent or translucent so that the ink image 13 can be accurately retransferred onto the transfer object at the time of pressure-sensitive retransfer, and in particular, the thermal transfer image is completely retransferred. It is desirable that the sheet is a translucent sheet that can be easily checked whether or not the sheet is transparent.

As the substrate 11 having such characteristics, a plastic film, paper, metal foil, or the like is generally used. Examples of the plastic film include a fluorine-based film made of a fluororesin such as ethylene, polypropylene, ethylene-tetrafluoroethylene copolymer or tetrafluoroethylene-hexafluoroethylene copolymer,
Polyethylene terephthalate, nylon, polyimide,
Polyvinyl chloride, polycarbonate, polysulfone,
Examples thereof include an ethylene-vinyl acetate copolymer, an acrylonitrile-butadiene-styrene copolymer, and an ionomer.

Next, the surface treatment agent layer 12 formed on one surface of the base material 11,
It is desirable that the coefficient of static friction of the surface is 0.25 or more, preferably 0.3 or more.

This is necessary so that when the ink image 13 is re-transferred from the sheet onto the object to be transferred, the sheet is fixed so as not to move and be displaced, and a complete re-transfer image can be formed.

Further, the contact angle with water is 80 to 120 °, preferably 80 to 110 °.
By setting ゜, the adhesive force between the ink image 13 and the retransfer sheet can be increased, so that even a small pressing pressure can prevent retransfer of unnecessary portions. And since it peels off even if it rubs, handling becomes easy.

Further, heretofore, when a large image is transferred by a thermal transfer apparatus, if the head is a small serial, it is necessary to form the image several times, and the image must be transferred in an overlapping manner. For this reason, there was a problem that the head was scraped off at the time of the next transfer of the previously transferred image, and a complete image could not be formed. Therefore, split the image line by line,
By separating and transferring, the image was prevented from being scraped by the head, and the re-transferred image was completed by successively aligning the divided images at the time of re-transfer, but if the sheet of the present invention is used, the adhesive force is reduced. Because of the large size, thermal transfer can be performed while a large image is connected.

Then, since the wettability is improved and the adhesive force is increased, it is possible to form a thermal transfer image with low thermal transfer energy, and a good quality image can be obtained.

Furthermore, it is desirable that the surface treatment agent layer has an elongation of 100% or more. Due to this, the surface treatment agent layer is unilaterally extended by applying pressure during retransfer,
The adhesion between the surface treatment agent layer and the image becomes weak. Therefore, even if the surface treatment agent layer has a good wettability and a large adhesive force, the retransfer property is improved.

Examples of the surface treatment agent layer include polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer, ethylene-methacrylic acid copolymer, and silicone. And a mixture containing one or two or more of these as a main component.

However, in order to impart elongation or to advantage in manufacturing, a material having good wettability (contact angle to water 80
When (゜) or less is used, the wettability of the surface treatment agent becomes 80 ° or less, and the retransferability deteriorates. Further, when the applied energy at the time of thermal transfer for forming an image on the retransfer sheet is increased, the adhesive force between the ink image and the surface treatment agent layer becomes too strong, so that the retransfer property also deteriorates.

Therefore, by adding polyethylene fine powder into the composition of the surface treatment agent layer, the contact angle to water is 80 to 120.
By achieving ゜ and adjusting the amount of addition, the surface treatment agent layer having wettability corresponding to the applied energy can be easily adjusted.

In addition, when silicone was used, a curing time of at least 30 seconds was required at a high temperature of 100 ° C. or more in order to cure, but when polyethylene fine powder was added, 100 ° C. or less, It can be dried in a short time at a low temperature of 30 seconds or less.

Furthermore, surface treatment agents using silicone or fluorine compounds form a strong thin film on the surface of the equipment used during production and coating, making cleaning difficult, and when using that equipment for other purposes, It causes problems such as repelling. In addition, when the surface treatment agent layer is not sufficiently dried, there is also a problem that the surface treatment agent layer adheres to the back surface of the retransfer sheet or falsifies.
However, the surface treatment agent layer to which the polyethylene fine powder is added can easily wash the used equipment, and does not cause problems of insufficient drying and back-inside.

Furthermore, in the case of polyethylene fine powder, the material of the surface treatment agent layer can be satisfactorily dispersed without considering solubility in a solvent and compatibility with other resins and waxes. This is very advantageous for selection and production.

The polyethylene fine powder is blended in a proportion of 0.01 to 50 parts by weight, and a polyethylene fine powder having an elongation of 100% or more is blended in a proportion of 0.01 to 90 parts by weight.

By providing such a surface treatment agent layer on the sheet, thermal transferability, retransferability, abrasion resistance, image adhesion during handling, fixing of the sheet during retransfer, and the like are good. Thus, it is possible to obtain a retransfer sheet having no problem during coating. In addition, the wettability can be arbitrarily adjusted.

The ink ribbon used to thermally transfer a desired transfer image onto the retransfer sheet is a wax-based ink used in a printing device such as a normal thermal transfer type printer, typewriter, or word processor. Although it does not matter at all, it is preferable to use an ink ribbon having a two-layer structure composed of a transferability adjusting layer and an ink layer, which is further improved in thermal transferability and pressure-sensitive retransferability. This transferability adjusting layer is provided on the ink layer as a top coat layer, and has a higher heat-sensitive adhesiveness, hardness, viscosity, and cohesive force than the ink layer. The heat-sensitive transferability onto the retransfer sheet is significantly improved, and the pressure-sensitive retransfer can be performed integrally. In addition, by providing the ink layer with pressure-sensitive adhesiveness, the pressure-sensitive retransfer property is further improved.

[Examples] Hereinafter, some examples of the present invention will be described to clarify the present invention more specifically. However, the present invention is not limited by such descriptions. That goes without saying.

In addition, in addition to the following examples, and in addition to the above-described specific description, various changes, modifications, and changes to the present invention may be made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that improvements and the like can be made.

Example 1 A surface treatment agent having the following composition was coated on a polyethylene terephthalate film having a heat of 50 μm to obtain a retransfer sheet having a smooth surface having a contact angle with water of 95 ° and a coefficient of static friction of about 0.32. Was. The elongation of this surface treatment agent layer is 650%
It is.

This surface treating agent was obtained by dispersing it in a ball mill without considering solubility, compatibility and the like, whereby a good dispersion was obtained, and it could be produced without problems during production and coating. After coating, drying was performed at 80 ° C. for 20 seconds to form a good dry thin film having a heat of 5 μm. Composition by weight of surface treatment agent Ethylene-vinyl acetate copolymer 9 [EVAFLEX640 manufactured by Mitsui DuPont Polychemicals Co., Ltd.] Polyethylene fine powder 1 [Flow beads LE-1080 manufactured by Iron and Steel Chemical Industry Co., Ltd.] Toluene 90 A thermal transfer-type word processor (NP-510 manufactured by Brother Industries, Ltd.)
In 0), the ink was thermally transferred to obtain a dry transfer material having a desired transfer image. At that time, the energy could be reduced as compared with the related art, and a good transfer image could be obtained. Then, using the obtained dry transfer material,
When pressure-sensitive retransfer was performed to a transfer object such as paper or plastic, a clear retransfer image could be obtained. In addition, since there is little movement of the sheet and the image can be fixed and retransferred, there is an advantage that a good retransfer image is easily obtained.

By the way, the thickness of this surface treatment agent layer is 1 μm, 3 μm, 5 μm.
When changed to m, retransferability was good in the order of 5 μm, 3 μm, and 1 μm. This is considered to be because the larger the thickness, the larger the absolute amount of elongation.

Further, by determining the amount of the polyethylene fine powder to be added in accordance with the energy applied to the thermal head, good thermal transfer quality and good retransfer quality were obtained.

Furthermore, when the equipment used during manufacturing and coating is washed using toluene, it can be easily washed,
It can be used for other purposes.

[Effects of the Invention] As is clear from the above description, in the present invention, a re-transfer sheet is used to prepare a dry transfer material using a printing device such as a thermal transfer type printer, typewriter, or word processor. The ink image is thermally transferred to the surface treatment agent layer of (1). The surface treatment agent layer has an elongation of 100% or more, and contains, in the composition of the surface treatment agent layer, a material having a contact angle to water of 80 ° or less and polyethylene fine powder dispersed therein. The surface has good conformability, has a uniform surface without repelling and unevenness, can be thermally transferred to a surface having better wettability than in the past, and the ink image can be satisfactorily pressure-retransferred. Therefore, the thermal transfer energy required in the printing device can be reduced, and a clear ink image can be obtained.

And, by adjusting the addition amount of the polyethylene fine powder in accordance with the applied energy at the time of thermal transfer, the wettability of the surface treatment agent layer can be adjusted, so that the optimal thermal transfer quality on the surface treatment agent layer and The optimum re-transfer quality when pressure-sensitive re-transfer onto an arbitrary image receiving body is obtained.

In addition, substances that have not been available until now and have a contact angle with water of 80 ° or less can be used.

Further, since the adhesive force between the ink image and the surface treatment agent layer is large, the scratch resistance is improved and the handling becomes easy.

Furthermore, since the coefficient of static friction can be increased, the sheet can be easily fixed at the time of retransfer, and a complete retransfer image can be formed.

Furthermore, by including the polyethylene fine powder in the composition of the surface treatment agent layer, the surface treatment agent layer can be dried at a low temperature in a short time, and the production cost can be reduced.

And by using polyethylene fine powder,
It is easy to wash the equipment used during the coating of the surface treatment agent layer during production, taking into account the compatibility of the other components of the surface treatment agent layer with the polyethylene fine powder, and the solubility of the polyethylene fine powder and the solvent. Since there is no need, the surface treatment agent layer can be produced very easily.

By the way, when an ethylene-vinyl acetate copolymer or polyethylene is used as the composition of the surface treatment agent layer, the elongation of the surface treatment agent layer can be easily increased to 100% or more, and the ethylene-vinyl acetate copolymer or polyethylene is used. In contrast, the polyethylene fine powder is reliably dispersed, and the ink image is uniformly and thermally transferred to the surface of the surface treatment agent layer, thereby improving the quality of the retransferred image.

Further, the static friction coefficient of the surface treatment agent layer is 0.25 or more,
In addition, if the contact angle with water is 80 to 120 °, the fixing of the sheet at the time of retransfer becomes easier, and the quality of the retransfer image is improved.

[Brief description of the drawings]

The drawing is a sectional view showing an example of the retransfer sheet according to the present invention. In the drawing, 10 is a retransfer sheet, 11 is a base sheet, 12 is a surface treatment agent layer, and 13 is an ink image.

Claims (4)

(57) [Claims] An ink image thermally transferred onto a base sheet by a thermal transfer method is pressed from a surface of the base sheet opposite to an ink image transfer side to transfer the ink image to an arbitrary receptor. In a retransfer sheet of a dry transfer material for retransfer, a surface treatment agent layer formed on the surface on the ink image transfer side of the base sheet has an elongation of 100% or more, and the composition of the surface treatment agent layer A retransfer sheet comprising a material having a contact angle to water of 80 ° or less and a fine polyethylene powder dispersed therein. 2. The retransfer sheet according to claim 1, wherein the elongation is realized by an ethylene-vinyl acetate copolymer contained in the composition of the surface treatment agent layer. 3. The retransfer sheet according to claim 1, wherein the elongation is realized by polyethylene contained in the composition of the surface treatment agent layer. 4. The retransfer sheet according to claim 1, wherein the surface treatment agent layer has a static friction coefficient of 0.25 or more,
And a retransfer sheet having a contact angle with water of 80 to 120 °.