JPH0732794A - Transfer sheet - Google Patents

Abstract

PURPOSE:To obtain a transfer sheet having high disposability of a base material to be peeled in the case of transferring by providing a transfer layer and an adhesive layer on one surface of the material formed of degradable plastic through a peeling layer. CONSTITUTION:The transfer sheet 1 comprises a transfer layer 4 and an adhesive layer 5 laminated on a base material 2 through a peeling layer 3, wherein the material 2 is formed of degradable plastic having a softening point of 100 deg.C such as degradable polyethylene resin, degradable polypropylene resin, etc. As the plastic, light degradable and biodegradable ones are used. As the light degradable plastic, copolymer of ethylene and carbon monoxide. As the biodegradable one, polyolefin, polycaprolactum, starch and mixture with polyester to be polymerized by bioorganism.

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 more particularly, it relates to a transfer sheet in which a base material to be peeled off at the time of transfer is highly disposable.

[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 and an arbitrary shape and pattern that are 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. others,
Various transfer sheets such as a transfer sheet for transferring a print layer of a picture or a pattern and a heat transfer sheet of a melting type or a sublimation type are used.

Usually, a transfer sheet has a structure in which a release layer, a transfer layer and an adhesive layer are laminated on one surface of a base material, and a large amount of the released base material is generated during transfer to a transfer target. .
Such unnecessary base materials are discarded and incinerated or landfilled.

[0004]

However, the base material of the transfer sheet is required to endure thermocompression bonding at the time of transfer, and a heat resistant resin film such as polyethylene terephthalate is generally used as the base material. Therefore, when incinerating the unnecessary base material, a large combustion energy is generated, which causes damage to the incinerator, and when it is landfilled, the base body exists in the ground as it is without being decomposed, There was a problem that the ground of the landfill was not stable.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a transfer sheet in which a base material that is peeled off at the time of transfer and is unnecessary is highly disposable.

[0006]

In order to achieve such an object, the present invention provides a substrate formed of degradable plastic and a transfer formed on one surface of the substrate through a release layer. A layer and an adhesive layer formed on the transfer layer are provided.

[0007]

The transfer sheet is formed by laminating a transfer layer and an adhesive layer on one surface of a base material via a release layer, and the base material forming the transfer sheet is made of degradable plastic. Therefore, the base material that is peeled off and becomes unnecessary during the transfer to the transfer target body is naturally decomposed even if left untreated such as landfill processing.

[0008]

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 an adhesive layer 5 which are stacked on top of each other with a peeling layer 3 interposed therebetween.

The substrate 2 is made of degradable plastic. Examples of the degradable plastic that constitutes the base material 2 include degradable polyethylene resin and degradable polypropylene resin. The degradable polyethylene resin and the degradable polypropylene resin are resins containing polyethylene and polypropylene as main components and capable of being 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 by, for example, 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 , melting 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 resin and the degradable polypropylene resin, examples of the microbial degradable resin include a mixture of polyolefin, polycaprolactone, starch and polyester polymerized by microorganisms.

The polyethylene used for the microbial degradable polyethylene resin has a density of 0.87 to 0.95 g /
cm ³ , ethylene homopolymer 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 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 microbial degradable plastics is obtained by ring-opening polymerization of ε-caprolactone, and its weight average molecular weight (Mw) is usually 4
It is about 0000 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.
As a polyester polymerized by a microorganism used for a biodegradable plastic, a random copolymerized polyester of 3-hydroxybutyrate and 3-hydroxyvalerate (for example, propionic acid is added to hydrogen bacteria produced by ICI, UK). (Supplied and obtained)
And 3-hydroxybutyrate-based polyester obtained by supplying valeric acid to hydrogen bacteria.

The amount of polycaprolactone, starch and polyester polymerized by microorganisms in the above-mentioned microbial-decomposable polyethylene resin or polypropylene resin is 100% by weight based on the total amount of polyethylene or polypropylene and each of the above-mentioned mixed components. 5 to 80% by weight is preferable. If the mixing amount of each of the above components is less than 5% by weight, sufficient microbial degradability cannot be obtained, and if it exceeds 80% by weight, the strength is weakened, which is not preferable.

Two or more kinds of each component of polycaprolactone, starch and polyester polymerized by microorganisms may be used, but in this case, the total amount of mixture 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 of the microbial degradable polyethylene resin, a degradable polyethylene resin having both photodegradability and microbial degradability can be obtained.

The above degradable plastic has a softening point of 1
A degradable plastic having a temperature of 00 ° C. or higher, preferably 150 ° C. or higher is suitable. As a result, the durability against thermocompression bonding during transfer becomes sufficient. Further, in the above degradable plastic, in order to increase strength, calcium carbonate, magnesium carbonate, calcium sulfate, calcium sulfite, barium sulfate, metal salts such as magnesium sulfate, silicic acid or kaolin, silicates such as talc,
Metal oxides such as titanium oxide and zinc oxide and inorganic fillers such as aluminum hydroxide and aluminum compounds such as alumina may be contained. Further, various additives such as an antioxidant, a decomposition accelerator, a stabilizer, an antistatic agent and a surfactant may be contained. These additives may improve the heat resistance of the base material, and the softening point thereof may be 100 ° C. or higher. Examples of such degradable plastics include hydroxybutyric acid / valeric acid polymers (Tmp = 100 to 200 ° C.) having a molecular weight of more than 100,000, dicarboxylic acid / diol polycondensates (Tmp = 100 to 150 ° C.), polylactic acid ( Tmp
= 180 to 250 ° C.) is suitable.

The base material 2 formed of the above decomposable plastic preferably has a thickness of about 1 to 300 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 is, for example, a curable acrylic resin, a cellulose resin,
It can be formed of vinyl resin, urethane resin, butyral resin, or the like, and 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 thermal recording layer is a thermal transfer (sublimation transfer type and melt transfer type),
It can be appropriately selected from known recording means such as 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, 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 are dispersed in a matrix material made of a resin. Examples thereof include those prepared, and those containing a liquid crystal substance in the film forming polymer substance.

The adhesive layer 5 may be the same as the adhesive layer of the conventional transfer sheet, and can be appropriately selected in consideration of the material of the transferred material. For example, a known adhesive such as an acrylic resin, a vinyl resin, a polyester resin, a urethane resin, an amide resin, an epoxy resin, a rubber resin, or an ionomer resin can be used. The thickness of the adhesive layer 5 is 0.1 to 50 μm.
m, preferably about 1.0 to 10 μm.

[0028]

As described above in detail, according to the present invention, the transfer sheet is formed by laminating the transfer layer and the adhesive layer on one surface of the base material via the release layer, and the base material is decomposed. Since it is made of flexible plastic, the base material that is no longer needed after being peeled off during transfer to the transfer target will decompose naturally even if left untreated such as landfill without incineration. Therefore, the ground can be stabilized and the disposability can be greatly improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a transfer sheet of the present invention. DESCRIPTION OF SYMBOLS 1 ... Transfer sheet 2 ... Substrate 3 ... Release layer 4 ... Transfer layer 5 ... Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C09J 7/02 JHR JJL

Claims (2)

[Claims] 1. A base material formed of degradable plastic, a transfer layer formed on one surface of the base material via a release layer, and an adhesive layer formed on the transfer layer. A transfer sheet characterized in that 2. The degradable plastic has a softening point of 10
The transfer sheet according to claim 1, which is a degradable plastic having a temperature of 0 ° C or higher.