JPS6141438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of an information recording card in which an ink absorbing layer and a lubricating layer are formed on a card substrate, and then ink is transferred from a thermal transfer ribbon by heat-pressure contact using a thermal recording head or the like to record an image. Regarding the method.

In recent years, there has been an increase in the number of industrial fields in which the following requirements regarding recording, printing, marking, etc. are strongly desired. In other words, information recording cards such as various securities, card certificates, commuter passes for automatic ticket gates, labels, etc. that must withstand harsh usage conditions for a long period of time have abrasion resistance, weather resistance, water resistance, and durability. It must be solvent-resistant, tamper-proof, stain-resistant, and the information recording method must be easy to output by storing information on a computer, etc., and the mechanism and operation must be simple. .

Conventionally used electrophotographic methods and electrostatic recording methods generally have the drawbacks of complex, large, and expensive equipment, and require consumables such as developers, which requires maintenance and management. It also had the disadvantage of being complicated. Considering this point, the thermal transfer recording method has a simple mechanism, fewer consumables, and low running costs.
It has been evaluated as a preferred recording method, and has begun to be actively applied not only to facsimiles using paper as a recording medium, but also to information recording that requires durability of recorded images, such as information recording cards, which are the object of the present invention.

However, in the past examples of application, in order to obtain a durable recorded image, a fixing means was further applied after the image was formed to strengthen the ink in the image area so that it would not easily peel off. This is due to the fact that the ink does not penetrate into the card substrate but merely adheres to the surface. For this purpose, infrared heaters, flash lamps, and ultraviolet lamps have been installed as fixing means for irradiation, but these devices have become complicated and have disadvantages such as increased running costs.

In view of this, as a result of intensive research, the present invention has completed a highly practical method for producing an information recording card that allows sufficient penetration of ink, is durable, and has no background stains, and is provided herein. It is something.

The recording medium of the present invention has a base 2 made of plastic, metal, or strong paper, and has an ink absorbing layer 3 on its surface that can absorb and retain ink, and further has an ink absorbing layer 3 on which ink can pass through and prevents scumming. A two-layer recording layer including a slippery layer 4 is provided. Since the most practical method for forming this recording layer is to apply a coating liquid, the coating film will be described in detail below.

First, the method for forming the coating film of the ink absorbing layer will be described below. The basic composition of the coating liquid consists of particles, a resin that uniformly disperses and binds the particles, and an organic solvent that dissolves the resin. As specific examples of particles, all commonly used inorganic or organic white pigments can be used.

Note that if a colored recording layer is required, colored pigments may be used. For example, titanium oxide, calcium carbonate, zinc oxide, silicon oxide, barium sulfate, lead carbonate, alumina, clay, etc. can be used.

On the other hand, regarding resins, binder resins commonly used in paints and inks, such as polyester, phenyl, alkyd, acrylic,
Epoxy resins, polyurethane resins, modified cellulose resins, and mixtures thereof can be used. Kneading and dispersion for preparing a coating liquid is performed by a well-known method. This coating solution is applied to a durable substrate such as plastic or metal and dried to form an ink absorbing layer. Note that a well-known coating method may be applied for coating. As a result of intensive studies, the following requirements were clarified in order for this coating film to have properties as an ink absorbing layer. First, the pigment/resin composition ratio has a significant effect on recording properties (related to the porosity of the coating film), coating strength, adhesion to the substrate, and abrasion resistance, and all conditions must be met. In order to achieve this, the pigment/resin composition ratio must be in the range of 1/3 to 4/1 by weight.
Note that the full range mentioned above may not be applicable depending on the pigment material type, pigment particle size, and shape, but the common range for all material configurations is 1/3 to 4/1.
It is. Next, regarding the particle size and particle size distribution of the pigment, the particle size is 0.5 to 5, taking into account porosity and surface roughness.
A particle size distribution as narrow as possible within the μ range provides good uniformity as an ink absorbing layer. Further, the appropriate thickness of the coating film is about 10 to 30 μm.

In addition, in order to improve the strength and solvent resistance of the coating film, it is more preferable to use a crosslinked binder resin. For example, well-known techniques can be applied as appropriate, such as selecting a polyester resin having a polyol group or a resin containing a polyurethane resin as the resin and adding an isocyanate group-containing compound or resin as a crosslinking agent to form a binder resin composition.

Incidentally, when the adhesive force between the substrate and the recording layer to be provided is weak, it is natural to provide an undercoat layer in advance to improve the adhesive force before coating the recording layer.

Next, the method for forming the coating film of the slipping layer will be described below. The basic composition of the coating liquid consists of white or nearly white solid lubricant particles, a binder resin that uniformly disperses and binds the particles, and an organic solvent that dissolves the resin. Examples of solid lubricants and particles include boron nitride, sulfur, mica, talc, aluminum stearate, calcium stearate, titanium sulfide,
White or nearly white fine powders of molybdenum sulfide, polyethylene, polyacetal, polytetrafluoroethylene, etc. are suitable. On the other hand, as for the resin, binder resins generally used in paints and inks, such as polyester, phenyl, alkyd, acrylic, epoxy, polyurethane, modified cellulose resins, and mixtures thereof, can be used. Kneading and dispersion for preparing a coating liquid is performed by a well-known method. This coating liquid is applied onto the above-mentioned ink absorption layer and dried to form a slippery layer. Note that for coating, a well-known coating method may be applied. This slippery layer allows information recording ink to pass through,
As a result of studies to obtain properties with lubricity that should also prevent scumming, the following requirements were further clarified. First, the solid lubricant particle/resin composition ratio has a large effect on ink permeability, coating film strength, adhesion with the ink absorption layer, and abrasion resistance, but in order to satisfy all conditions, a solid lubricant must be used. The composition ratio of /resin must be in the range of 2/1 to 20/1 by weight. Next, regarding the particle size, if it is too small, the ink permeability will decrease, and if it is too large, the surface roughness will become too large and the scumming prevention effect will decrease, so the optimum particle size range is 0.5~
Must be 10μ. Regarding the thickness of the next coating film, we considered that if it is too thin, it will not be able to sufficiently cover the surface of the ink absorbing layer below, and if it is too thick, the ink permeability will decrease. The thickness should be 2 to 10μ.

The recording method applied to the present invention is a thermal transfer recording method, and any recording device currently in use or developed can be used as appropriate. A detailed explanation of the recording device will be omitted since it is not the gist of the present invention, but FIG. 2 shows a conceptual diagram of obtaining an information recording card by thermal transfer recording of the present invention. The information recording card 1 includes a base 2, an ink absorption layer 3, and a slippery layer 4 provided thereon.

The thermal transfer ribbon 5 has an ink layer 7 provided on a ribbon base 6. The card 1 and the thermal transfer ribbon 5 are sandwiched between the thermal recording head 8 and the pressure roller 9 so that the ink layer side is in contact with the card surface, and when they are heated and pressed, the ink in the heated area is transferred to the card and at the same time it slides. The ink passes through the liquid layer 4 and is absorbed and retained in the ink absorbing layer 3. The portion 10 through which the ink has passed and the portion 11 where the ink has been absorbed and retained form an image portion.

The ribbon base of the thermal transfer ribbon used here is
Cellophane, glassine paper, or polyester film with a thickness of 10 to 20 μm is preferable, and the ink layer preferably has a property of rapidly softening at 50 to 90° C. in consideration of absorption and permeability of the ink into the card. Therefore, the binder is selected from those commonly used in hot melt adhesives such as wax, rosin, epoxy resin with a low degree of polymerization, phenol resin, petroleum resin, butyral resin, etc., and the binder contains carbon black and dye as colorants. An ink layer can be formed by mixing and dispersing ~30% by weight.

In the information recording card obtained in this way, the ink is absorbed and retained inside the card at the same time as recording, and does not remain on the surface of the card, so there is no need for any fixing means after recording, and the image remains unchanged. It is characterized by extremely excellent wear resistance, solvent resistance, and tamper resistance.

In addition, the slippery layer of the present invention can withstand card smudges and mechanical damage, even when the card is used harshly over a long period of time, such as when a magnetic commuter pass is passed through an automatic ticket gate many times. Extremely effective against wear.

Of course, it is possible to print a desired picture, character, or background pattern on this information recording card in advance depending on the coating used. Furthermore, for applications in which magnetic recording is used in addition to visual images as input information, an information recording card may be provided with a part of the base or a magnetic recording layer.

Next, an example will be explained.

Example 1 2 parts of powdered silica (manufactured by Mizusawa Chemical Co., Ltd./average particle size 2μ) and (the same weight ratio) polyurethane resin (Japan A mixed solution consisting of 4 parts of polyester polyol/isocyanate (manufactured by Polyurethane Co., Ltd.), 8 parts of methyl ethyl ketone, and 2 parts of toluene was stirred for about 20 minutes in a screw-type disperser, and the uniformly dispersed coating liquid was applied to a roll coater. The ink absorbing layer was formed by coating and drying. The film thickness was 20μ. On top of that, 7 parts of powdered talc (average particle size 3μ), 1 part of polyurethane resin
About 10 parts of methyl ethyl ketone, 8 parts of toluene, and 2 parts of toluene were mixed in a screw-agitating disperser.
The coating solution was uniformly dispersed by stirring for several minutes and then applied using a roll coater, and dried to form a slippery layer with a thickness of 4 μm. This was cut into a predetermined size and made into a card.
The thermal transfer ribbon is made by forming an ink layer of carnauba wax and carbon wax (weight ratio 4/1) on 20μ glassine paper to a thickness of 3.5μ.

When transfer recording was performed using this card and a thermal transfer ribbon using a thermal recording head, a clear penetration image was formed. No thermal determination was performed immediately after recording, but
Even when I rubbed the surface of this guard vigorously with my finger, the ink did not disappear or run.

Furthermore, although this card was ventilated 2000 times through the magnetic information reading head and its transport system, the card was not damaged or soiled at all, and there was no deterioration such as erasure of recorded images.

Example 2 Calcium carbonate powder (manufactured by Shiroishi Calcium Co., Ltd.) 8 on a 700μ thick white polyvinyl chloride sheet
1 part of polyester resin (Toyobo Co., Ltd.), 0.2 parts of nitrocellulose (manufactured by Daicel), 15 parts of methyl ethyl ketone, and 15 parts of toluene were kneaded in a ball mill for about 4 hours, and then the coating liquid was mixed with a roll coater machine. It was coated and dried to form an ink absorbing layer.Furthermore, on top of that, 2 parts of nitrogen boron powder (manufactured by Denki Kagaku Kogyo Co., Ltd.) and 1 part of nitrocellulose were added.
15 parts of isopropyl alcohol, and 3 parts of toluene were stirred for about 1 hour using a screw-type stirrer disperser to uniformly disperse the coating liquid, which was then applied using a gravure coater and dried to form a film with a thickness of 3 μm. A slippery layer was formed. This was cut into a predetermined size and made into a card. When transfer recording was performed using this card and the thermal transfer ribbon used in Example 1 with a thermal recording head, a clear penetration image was formed. Although no heat fixing was performed immediately after recording, the ink did not disappear or run even when the surface of the card was strongly rubbed with a finger.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a configuration diagram of an information recording card produced according to the present invention, and FIG.
The figure is a conceptual diagram explaining the present invention. DESCRIPTION OF SYMBOLS 1... Information recording card, 2... Basic, 3... Ink absorbing layer, 4... Lubricating layer, 5... Thermal transfer ribbon, 6... Ribbon base, 7... Ink layer, 8...
Heat-sensitive recording head, 9...pressure roller.

Claims (1)

[Claims] 1. After providing an ink absorbing layer with a thickness of 10 to 30 μm for absorbing and retaining information recording ink on a card substrate, the ink can be passed over the ink absorbing layer. Provide a slippery layer with a thickness of 2 to 10μ,
A method for manufacturing an information recording card, in which ink is then transferred from a thermal transfer ribbon by heating and pressure using a thermal recording head or the like to form a recorded image, and a permanent image can be obtained without using any fixing means after transfer. 2. The ink absorbing layer is made of a white or nearly white pigment with a particle size of 0.5 to 5 μm and a resin that uniformly disperses and binds the pigment, and the pigment/resin composition ratio is 1/3 to 4/1 by weight. 2. A method for manufacturing an information recording card according to claim 1, wherein the information recording card is provided as follows. 3. The lubricating layer is made of white or nearly white solid lubricant particles with a particle size of 0.5 to 10μ and a resin that uniformly disperses and binds the particles, and the composition ratio of particles to resin is 2/1 to 2/1 by weight. 20/1. The method for manufacturing an information recording card according to claim 1, wherein the information recording card is provided so as to have a ratio of 20/1.