JPH0732530A - Transfer sheet and recording medium - Google Patents

Abstract

PURPOSE:To provide a transfer sheet wherein a transfer layer after transfer can be easily peeled from a material to be transferred if necessary and a recording medium easily reutilizing the substrate thereof. CONSTITUTION:A transfer sheet 1 is constituted by laminating a transfer layer 4 and a decomposable adhesive layer 5 to one surface of a base material 2 through a release layer 3. A recording medium has the transfer layer 4 formed through the decomposable adhesive layer 5 by placing the transfer sheet 1 on the base material 2 to bond the same under heating and pressure and peeling the base material and the release and removal of the transfer layer 4 from the base material are made possible by the decomposition of the decomposable adhesive layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer sheet and a recording medium, and more particularly to a recording medium in which a transfer layer after transfer can be easily peeled off from an object to be transferred and a substrate in which a substrate can be easily reused. .

[0002]

2. Description of the Related Art Conventionally, various transfer sheets have been used. For example, a transfer sheet used for so-called foil stamping enables a texture that is difficult to create by printing. Further, the magnetic transfer sheet is used for forming a magnetic layer on a recording medium. Since the magnetic layer formed by transfer does not have a base material layer and is difficult to peel off, it is effective in preventing forgery.

A recording medium created by forming a picture, a recording portion, etc. in a desired shape and pattern on a substrate using the various transfer sheets as described above is a credit card, a cash card or a disposable telephone. There are various things such as cards. Then, these cards are discarded after the expiration date or after a predetermined amount of money has been used, and are incinerated or landfilled.

However, in the case of incineration, if the substrate is plastic, a large combustion energy is generated, which causes damage to the incinerator, and in the case of landfilling, the plastic substrate remains in the ground in its original form without being decomposed. So
There was a problem that the ground of the landfill was not stable.

[0005]

By the way, in recent years, there has been an increasing demand for effective use of resources, and in consideration of the various problems described above, it is possible to collect and reuse recording media without making them disposable. Has been done. However, if the collected recording medium has a transfer forming portion such as a recording portion or a pattern portion formed by transfer, it is difficult to remove these transfer forming portions, which hinders reuse of the substrate of the recording medium. I was coming.

The present invention has been made in view of the above circumstances, and a recording sheet in which a transfer layer after transfer can be easily peeled off from a transfer object and a substrate can be easily reused if necessary. The purpose is to provide a medium.

[0007]

In order to achieve such an object, the transfer sheet of the present invention comprises a substrate, a transfer layer formed on one surface of the substrate through a release layer, and It was configured to include a degradable adhesive layer formed on the transfer layer.

Further, the recording medium of the present invention is formed by interposing a substrate and the above-mentioned transfer sheet on at least one surface of the substrate, thermocompressing and peeling the substrate to form a degradable adhesive layer. And a transfer layer that has been formed.

[0009]

The transfer sheet is constructed by laminating a transfer layer and a decomposable adhesive layer on one surface of a base material with a release layer interposed therebetween, and the transfer layer transferred to a transfer target using this transfer sheet. Is
The transfer layer is fixed to the transfer target through the degradable adhesive layer, and the transfer layer is separated and removed from the transfer target by the decomposition of the degradable adhesive layer. In the recording medium having the transfer layer formed thereon, it becomes easy to recover only the substrate by decomposing the degradable adhesive layer at the disposal stage after use.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing the structure of the transfer sheet of the present invention. In FIG. 1, a transfer sheet 1 is a base material 2
It has a structure including a transfer layer 4 and a degradable adhesive layer 5 which are laminated on top of each other with a peeling layer 3 interposed therebetween.

As the base material 2, the base material used in the conventional transfer sheet can be used without any particular limitation. Specifically, those having high heat resistance such as polyester resin film, polyamide resin film, polyimide resin film, and polycarbonate are preferable, and the thickness is 1 to 3.
It is preferably about 00 μm.

The release layer 3 is formed of a release agent such as wax, silicone wax, silicone resin, fluororesin, acrylic resin or the like. The peeling layer 3 is formed by applying an ink prepared by dissolving or dispersing the above resin to which the necessary additives are added in a suitable solvent onto a base material by a known means and drying it. be able to. The thickness of the release layer 3 is preferably about 0.5 to 5 μm. An overprint layer may be formed between the peeling layer 3 and the transfer layer 4 in order to improve the adhesiveness of both layers and the durability of the transfer layer. The overprint layer can be formed of, for example, a curable acrylic resin, a cellulose resin, a vinyl resin, a urethane resin, a butyral resin, or the like.
The thickness is preferably about 0.1 to 5.0 μm.

The transfer layer 4 can be formed according to the purpose of use of the transfer sheet 1. For example, in the printing layer such as a pattern as the transfer layer 4, a pigment of each color is added to a binder such as a cellulose resin, a polyester resin, a vinyl chloride resin, a polyurethane resin and a polystyrene resin, and if necessary, a plasticizer and a stabilizer are added. It can be formed by a known coating method or printing method using a colored coating material or ink which is sufficiently kneaded with a solvent or a diluent after adding an agent, a wax, a drying agent, a curing agent, a thickening agent and the like.

When a magnetic recording layer is formed as the transfer layer 4, for example, γ-Fe ₂ O ₃ and Co deposited γ-Fe _{2
O 3, Fe 3 O 4,} Fe-Cr, Fe-Co, Co-C
A known coating method such as a gravure method, a roll method, or a knife edge method is used to prepare a dispersion prepared by dispersing a magnetic material such as r, Co-Ni, Ba-ferrite, Sr-ferrite, or CrO ₂ in a suitable resin or ink vehicle. A magnetic recording layer can be formed by coating according to the above. In addition, Fe, Fe-Cr, Fe-Co, Co-Cr
Using a metal or alloy such as, or its oxide,
The magnetic recording layer can be formed by a vacuum vapor deposition method, a sputtering method, a plating method, or the like.

As the transfer layer, known recording means such as a heat-sensitive recording layer, a heat-sensitive rewrite layer, an optical recording layer and a hologram layer can be formed. Of these, the heat-sensitive recording layer can be appropriately selected from known recording means such as heat-sensitive transfer (sublimation transfer type or melt transfer type), heat-sensitive color development and heat-sensitive destruction according to the purpose of use. Further, the heat-sensitive rewrite layer may be one that can stably record and erase by heating. Specifically, in the matrix material made of resin,
A dispersion of at least one aliphatic carboxylic acid selected from aliphatic monocarboxylic acids and aliphatic dicarboxylic acids and an organic low molecular compound having a polyoxyethylene chain, in a film-forming polymer substance Examples thereof include those containing a liquid crystal substance.

The degradable adhesive layer 5 is formed from degradable plastics, such as degradable polyethylene resin having heat sealability, degradable polyolefin resin such as degradable polypropylene, polyvinyl alcohol, and degradable polyester.

The decomposable polyolefin resin is a resin whose main component is polyolefin and which can be decomposed by light or microorganisms.

Among the degradable polyethylene resins, examples of the photodegradable ones include copolymers of ethylene and carbon monoxide. This ethylene / carbon monoxide copolymer is
It is considered that the cleavage occurs due to light between the second and third carbons to which the carbonyl group is bonded, resulting in decomposition. The decomposition rate can be controlled by the content of carbon monoxide in the copolymer. Usually, the density of ethylene / carbon monoxide copolymer is about 0.89 to 0.95 g / cm ³ , and the content of carbon monoxide is about 0.1 to 10 mol%.

The above-mentioned ethylene / carbon monoxide copolymer can be obtained, for example, by adding ethylene and carbon monoxide at a temperature of 230 ° C.
It can be produced by coexisting under a pressure of about 2000 atm.

As the photodegradable degradable polyethylene resin or degradable polypropylene resin, polyethylene (density = 0.87 to 0.95 g / cm ³ , melt index (M
I) = 0.4-40) and polypropylene (density = 0.8
7 to 0.91 g / cm ³ , melting index (MI) = 0.3 to 5
It is also possible to use a mixture of 0) and an organic acid metal salt.
Examples of the organic acid metal salt include iron stearate, cerium stearate, cobalt stearate, and the like, and metal oxides such as iron oxide, acetylacetone, and a complex with dibutyldithiocarbamate, and the like, and the mixed amount of the organic acid metal salt. Is preferably about 1 to 5000 p.pm. Further, a copolymer with vinyl ketone may be added.

Among the degradable polyethylene resins and degradable polypropylene resins, examples of microbial degradable ones include mixtures of polyolefin with polycaprolactone, starch and polyesters polymerized by microorganisms.

The polyethylene used for the biodegradable polyethylene resin has a density of 0.87 to 0.95 g / cm.
³ , a homopolymer of ethylene having a melting index (MI) of 0.4 to 40, or a random or block copolymer with other olefins such as propylene, butene, hexene, octene, and 4-methylpentene-1, and further Examples thereof include copolymers with monomers having an ethylenically unsaturated group such as vinyl acetate, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, and marinic anhydride. The polypropylene used for the microbial degradable polypropylene resin has a density of 0.87 to
Examples thereof include a homopolymer of propylene having 0.91 g / cm ³ and a melting index (MI) of 0.3 to 50, or a random or block copolymer with other olefins such as ethylene and butene.

Polycaprolactone used for biodegradable plastics is obtained by ring-opening polymerization of ε-caprolactone, and its weight average molecular weight (Mw) is usually 40,
It is about 000 to 100,000. Starch is a polymer of D-glucose and is industrially produced from stems and roots of potato, sweet potato, corn, wheat and the like, and its weight average molecular weight (Mw) depends on the raw material and the production method. It greatly changes from ten thousand to tens of millions. The average particle size of such starch is preferably 10 μm or less.
In particular, polycaprolactone is suitable because it has a low melting point of 100 ° C. or lower.

As the polyester polymerized by the microorganism used for the biodegradable plastic, a random copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate (for example, hydrogen bacterium produced by ICI, UK) is used. And those obtained by supplying valeric acid to hydrogen bacteria, and the like, which are mainly composed of 3-hydroxybutyrate. Further, polyesters composed of dicarboxylic acid and diol and polyesters composed of polylactic acid are also suitable.

The amount of polycaprolactone, starch and polyester polymerized by microorganisms in the biodegradable polyethylene resin or polypropylene resin as described above is 100% by weight based on the total amount of polyethylene or polypropylene and the above-mentioned mixed components. As 5 each
-80 wt% is preferred. When the mixing amount of each of the above components is less than 5% by weight, sufficient biodegradability cannot be obtained, and when it exceeds 80% by weight, the strength of the adhesive layer becomes unfavorable.

Two or more kinds of each component of polycaprolactone, starch and polyester polymerized by microorganisms may be used, but in this case, the total mixing amount is 5 to 8.
It may be in the range of 0% by weight.

By using the above-mentioned photodegradable polyethylene resin as a raw material for the microbial degradable polyethylene resin, a degradable polyethylene resin having both photodegradability and microbial degradability can be obtained.

Further, various additives such as known inorganic fillers, antioxidants, decomposition accelerators, stabilizers, antistatic agents and surfactants are added to the degradable adhesive layer 5 containing the above degradable plastics. Agents may be added.

The thickness of such degradable adhesive layer 5 is
The thickness can be about 0.1 to 50 μm, preferably about 1.0 to 10 μm.

As described above, the transfer sheet 1 of the present invention is constructed by laminating the transfer layer 4 and the degradable adhesive layer 5 on one surface of the substrate 2 with the release layer 3 interposed therebetween. The transfer layer 4 that has been transferred to the transfer target using the above is fixed to the transfer target through the degradable adhesive layer 5, and the transfer layer 4 is transferred by the decomposition of the degradable adhesive layer 5. It can be peeled away from the body. The decomposable adhesive layer 5 is decomposed, for example, by forming the decomposable adhesive layer 5 with the above-mentioned photodecomposable resin and irradiating the degradable adhesive layer 5 with light. By promoting the decomposition of, it becomes possible to early decompose.

FIG. 2 is a perspective view showing an example of the recording medium of the present invention, and FIG. 3 is a partially enlarged sectional view taken along line III-III of FIG. 2 and 3, the recording medium 11 of the present invention has a structure in which the recording portion 13 is provided on one surface of the substrate 12.

The substrate 12 may be any substrate used in various conventional recording media and is not particularly limited. For example, transparent, opaque, colored or uncolored resin film, resin film having a reflective layer, paper, metal foil,
Sheets of glass, ceramics, etc., molded bodies, etc., or composites thereof can be used. The thickness of the base material 2 is not particularly limited and can be appropriately determined according to the purpose of use of the recording medium 11.

The recording portion 13 comprises a transfer layer 14 formed on the substrate 12 with a degradable adhesive layer 15 interposed therebetween. Such a recording portion 13 can be formed by using the above-described transfer sheet of the present invention. That is, the transfer sheet 1 as shown in FIG. 1 is slit into a predetermined width, and the degradable adhesive layer 5 is placed on a predetermined portion of the base 12 so that the degradable adhesive layer 5 abuts on the base 12. It is possible to transfer the transfer layer 4 and the degradable adhesive layer 5 onto the substrate 12 by peeling the base material 2 after pressure bonding, thereby forming the transfer layer 14 and the degradable adhesive layer 15.

In this case, the transfer layer 14 may be any of a magnetic recording layer, a heat-sensitive recording (heat-sensitive transfer, heat-sensitive coloring, heat-sensitive destruction) layer, a heat-sensitive rewrite layer, an optical recording layer, a hologram layer, etc. The printed layer may be included.

In such a recording medium 11, the transfer layer 14
Is formed on the substrate 12 via the degradable adhesive layer 15, the transfer layer 14 can be peeled and removed by decomposing the degradable adhesive layer 15 at the disposal stage after use, and only the substrate 12 can be removed. It becomes easy to collect. In this case, the decomposition of the decomposable adhesive layer 15 is performed, for example, by forming the decomposable adhesive layer 15 with the above photodecomposable resin,
The degradable adhesive layer 5 is formed on the substrate 12 side or the transfer layer 14
By irradiating light from the side to accelerate the decomposition of the decomposable adhesive layer 15, it becomes possible to disassemble at an early stage. Further, in order to facilitate the decomposition, it is also preferable to mainly use a water-soluble material or a hydrolyzable material, to reduce the molecular weight, or to shorten the ethylene chain.

In the above example, the recording portion 13 has a stripe shape, but it is not limited to this, and it may be formed in a predetermined pattern or formed on the entire surface of the substrate 12. May be. Further, the recording unit 13
It may be a bar code, an OMR character, or the like. Further, it goes without saying that an overprint layer as described in the description of the transfer sheet of the present invention may be provided on the transfer layer 14.

[0038]

As described in detail above, according to the present invention, a transfer sheet is formed on a substrate, a transfer layer formed on one surface of the substrate via a release layer, and formed on the transfer layer. The transfer sheet is formed on the transfer object through the decomposable adhesive layer by placing the transfer sheet on the transfer object, thermocompressing the base material, and peeling the base material. The transfer layer can be peeled and removed from the transfer target by decomposing the decomposable adhesive layer, and therefore, a recording medium provided by forming a transfer layer on a substrate using such a transfer sheet, At the disposal stage after use, it is easy to recover only the substrate by decomposing the degradable adhesive layer, and the substrate can be reused. Further, by using the transfer sheet of the present invention, it is possible to quickly process a desired portion such as confidential information to be disposed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a transfer sheet of the present invention.

FIG. 2 is a perspective view showing an example of a recording medium of the present invention.

3 is a partial enlarged cross-sectional view taken along the line III-III in FIG. DESCRIPTION OF SYMBOLS 1 ... Transfer sheet 2 ... Base material 3 ... Release layer 4 ... Transfer layer 5 ... Decomposable adhesive layer 11 ... Recording medium 12 ... Substrate 13 ... Recording part 14 ... Transfer layer 15 ... Degradable adhesive layer

Claims (2)

[Claims] 1. A base material, a transfer layer formed on one surface of the base material via a release layer, and a degradable adhesive layer formed on the transfer layer. Transfer sheet. 2. A substrate and a transfer formed via a decomposable adhesive layer by placing the transfer sheet according to claim 1 on at least one surface of the substrate and thermocompressing the substrate to separate the substrate. A recording medium comprising a layer.