JPH08207430A - Tape for label writer - Google Patents

Abstract

PURPOSE: To produce a label having excellent resolution and coloring property, excellent environmental resistances such as light resistance, abrasion resistance, and water resistance by an ink jet method. CONSTITUTION: On a tape-like base material 1, an ink accepting layer 2 is provided. On the ink accepting layer 2, a porous polymer layer 3 which can be transparentized by heating is provided. On the porous polymer layer, a silica gel layer 4 is further laminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label writer tape, and more particularly to a label writer tape which can be printed by an ink jet method.

[0002]

2. Description of the Related Art A device called a label writer is known as a device for printing a label to be attached to a document or the like. A conventional label writer prints on a tape-shaped label base material by a thermal transfer method, and a label of various colors can be produced by combining a label base material of various colors and an ink ribbon. With this method, the label substrate and the ink ribbon must be replaced each time the color of the label is changed. Further, in the case of realizing full color, there is a problem that the consumption amount of the ink ribbon increases and the cost increases.

[0003]

On the other hand, the ink jet system is suitable as a recording system for a label writer because it can easily realize full color and is excellent in cost and image clarity. In the case of the inkjet method, the label base material needs to have high ink absorbency. Furthermore, the label is required to have environmental resistance such as scratch resistance and water resistance. Since an image is formed by a solvent-soluble dye in the inkjet method, the water resistance and weather resistance of the recorded matter are not always sufficient. In general, labels often come into contact with hands, and may be exposed to rain when used outdoors, and may be exposed to water or detergent when used for tableware, etc. High environmental resistance is required.

The present invention is a label for a label writer, which is capable of forming an image having good resolution and color developability by an ink jet method and easily producing a label having excellent environmental resistance such as scratch resistance and water resistance. An object is to provide a base material, that is, a tape for a label writer.

[0005]

According to the present invention, there is provided an ink receiving layer on a tape-shaped substrate, on which a porous polymer layer which can be made transparent by heating, and silica gel thereon. Provided is a label writer tape in which layers are laminated.

The material of the base material is not particularly limited, and various materials can be used. Specifically, various plastics such as polyester resins such as polyethylene terephthalate, polycarbonate resins, fluorine resins such as ETFE can be preferably used. Furthermore, natural paper, synthetic paper, cloth or a composite material thereof can be used.
These substrates may be subjected to treatments such as corona discharge treatment and undercoat for the purpose of improving the adhesive strength of the ink receiving layer.

When a transparent plastic film or the like is used as the substrate and a highly transparent ink receiving layer is used, a transparent label can be obtained. When an opaque plastic film containing a white or other color pigment or paper is used as the substrate, a white or colored label can be obtained. Even if the substrate is opaque, it is preferable that the transparency of the ink receiving layer is high because printing with high color density is possible.

The ink receiving layer formed on the substrate is preferably one mainly containing an inorganic oxide or a hydrate thereof, and particularly preferably silica gel or alumina gel.
In particular, a structure in which inorganic particles are bound with an organic binder is preferable. The inorganic particles are boehmite (Al ₂ O ₃ · nH ₂ O,
It is preferable that n = 1 to 1.5) because the ink-jet ink absorbency is good and the dye in the ink is excellent in fixability.

When the ink receiving layer is composed of hydrated alumina, the pore structure thereof is substantially composed of pores having a radius of 1 to 10 nm and the pore volume is 0.3 to 1.0 cc / g. However, it is preferable since it has sufficient absorbability and transparency. In addition to these physical properties, it is more preferable that the average pore radius of the porous alumina hydrate is 3 to 7 nm. The pore size distribution is measured by the nitrogen adsorption / desorption method.

As a method of forming the ink receiving layer, a method of applying a coating liquid in which a binder is preferably added to inorganic particles to a substrate is preferable. For example, in order to form a porous alumina hydrate layer having a pore structure as described above, alumina sol is preferably added with a binder to form a slurry, and a die coater, a roll coater, an air knife coater, a blade coater, a rod. It is preferable to adopt a method of coating on a substrate using a coater, bar coater, comma coater, etc. and drying.

As the binder, polyvinyl alcohol and its modified products, starch and its modified products, styrene-butadiene rubber (SBR) latex, nitrile-butadiene rubber (NBR) latex, hydroxycellulose, polyvinylpyrrolidone and other organic substances can be used. If the amount of the binder used is too small, the strength of the ink receiving layer may be insufficient. On the other hand, if the amount is too large, the amount of ink absorbed or the amount of dye carried may be low. About wt% is preferable.

If the thickness of the ink receiving layer is too thin, the dye cannot be sufficiently carried and a label having a low color density may be obtained, which is not preferable. On the other hand, if the thickness is too large, the strength of the ink receiving layer may be reduced, or the transparency may be reduced to impair the texture, which is not preferable. The preferable thickness of the ink receiving layer is 1 to 50 μm.

A porous polymer layer is provided on the ink receiving layer. This porous polymer layer is required to be capable of penetrating the ink up to the ink receiving layer when recording by an inkjet method, and densified by heating to make it transparent. The material of the porous polymer layer is not particularly limited, and a thermoplastic polymer latex is preferable.

Means for forming the porous polymer layer include:
It is preferable to form a polymer latex by coating and drying it on the ink receiving layer. As the polymer latex, polyvinyl chloride resin (PVC) latex, styrene butadiene rubber (SBR) latex, nitrile butadiene rubber (NBR) latex and the like can be used alone or in combination of two or more.

The polymer latex has an average particle size of 0.05.
It is preferably 0.5 μm. When the average particle size of the polymer latex is less than 0.05 μm, a porous polymer layer having good ink absorbability and permeability is not formed,
Ink may not sufficiently penetrate into the porous alumina hydrate layer to be fixed, and a desired image may not be formed. If the average particle size of the polymer latex is more than 0.5 μm, the dots of the ink may be non-uniform and the image may be deteriorated. The preferable average particle size of the polymer latex is 0.
It is 08 to 0.3 μm.

The minimum temperature for forming a polymer latex film is
It is preferably in the range of 50 to 150 ° C. The minimum film formation temperature is the minimum temperature at which a polymer latex film can be uniformly formed into a film when heated. In the present invention, after coating the polymer latex, in order to form a porous polymer layer, it is heated under the condition that the latex particles are bound to a degree that does not form a dense film but has a certain mechanical strength. Needs to be dried.

When the minimum film formation temperature is less than 50 ° C.,
When a polymer latex is applied and dried, a dense film is likely to be formed, and it is difficult to obtain a porous polymer layer. If it is attempted to prevent this, the drying time will be long and it is not industrially preferable. When the minimum film formation temperature is higher than 150 ° C., it is necessary to raise the heat treatment temperature after image formation, and there is a problem of polymer decomposition and coloring, and a problem of heat denaturation of the substrate or dye, which is not preferable. The more preferable minimum film formation temperature is 65 to 130 ° C.

The thickness of the porous polymer layer is 0.3 to 5 μm.
Is preferred. If the thickness is less than 0.3 μm, the effects of improving environmental resistance such as water resistance, scratch resistance, and weather resistance when formed into a film may not be sufficient, which is not preferable. If the thickness is more than 5 μm, the ink absorbency may decrease,
It is not preferable because the image quality may be deteriorated when cracks are formed to form a film, and the effects of improving the environmental resistance such as water resistance, scratch resistance, and weather resistance may not be obtained. The more preferable thickness of the porous polymer layer is 0.5 to 3 μm.

The solid content concentration of the polymer latex is not particularly limited, and it is preferable to appropriately use latex having a solid content concentration of 2.5 to 50% by weight. It should be noted that other polymer component having a binder action may be added to the polymer latex.

The method of applying the polymer latex is not particularly limited, and a die coater, roll coater, air knife coater, blade coater, rod coater, bar coater, gravure coater and the like can be used. The drying is preferably carried out at a temperature not higher than the minimum film-forming temperature of the polymer latex used.

A silica gel layer is laminated on the polymer porous layer. The silica gel layer functions as a protective layer for the porous polymer layer. The silica gel layer is preferably a porous body so that the ink penetrates and is fixed to the lower ink receiving layer when printed by an inkjet printer.
The thickness of the silica gel layer is preferably about 0.1 to 30 μm. When the thickness of the silica gel layer is less than 0.1 μm, the mechanical strength of the silica gel layer is insufficient and the protective effect of the polymer porous layer may be insufficient, which is not preferable. If the thickness of the silica gel layer exceeds 30 μm, the transparency of the silica gel layer may be insufficient and the color density of the image may decrease, which is not preferable.

The silica gel layer is preferably formed by forming a polymer porous layer and then applying silica sol together with a binder and drying. The silica sol has an average particle size of 10 to 90 nm and a solid content concentration of 1 to 20.
Weight% is preferable. As the binder, the same binder as used for forming the ink receiving layer can be used.

Particularly, the amount of the silicon-containing polymer binder used is 1 to 3 with respect to the solid content (SiO ₂ ) of silica gel.
0% by weight is preferred. When the amount of the binder used is less than 1% by weight, the mechanical strength of the silica gel layer may be lowered and the protective effect of the polymer porous layer may be insufficient, which is not preferable. When the amount of the binder used is more than 30% by weight, the ink absorbency and the ink permeability of the silica gel layer are insufficient and the ink is hard to be fixed on the ink receiving layer, which is not preferable.

In the tape of the present invention, an adhesive layer is formed on the back side of the recording surface, that is, the back side of the surface on which the ink receiving layer and the porous polymer layer are formed, and a release paper is further laminated. Is preferred. In this case, the tape can be stored in a cartridge in a wound form, and after the tape after printing is cut, the release paper can be peeled off and attached to a desired place.

The thickness of the release paper is preferably 10 to 200 μm. When the thickness of the release paper is less than 10 μm, it becomes difficult to remove the release paper, and conversely, when the thickness is more than 200 μm, the total thickness of the tape becomes large and the length of the tape that can be stored in the cartridge becomes short. Therefore, it is not preferable.

The width of the tape can be appropriately selected according to the desired label size. Generally, about 5 to 50 mm is suitable. In the manufacturing process, it is preferable to cut a sheet having a width larger than this into a tape. This tape is preferably wound into an appropriate diameter, placed in a cartridge made of resin or the like, and attached to a label writer.

An example of the cross section of the label writer tape of the present invention is shown in FIG. In FIG. 1, an ink receiving layer 2 is formed on a tape-shaped substrate 1, and a porous polymer layer 3 and a silica gel layer 4 are further laminated in this order. An adhesive layer 5 and a release paper 6 are laminated on the back surface thereof.

When characters and images are formed on the tape for label writer of the present invention from above the porous polymer layer by the ink jet method, the ink penetrates through the porous polymer layer and reaches the ink receiving layer to be fixed. It After that, when the porous polymer layer is densified by heat treatment, a transparent polymer film is formed.

The heating means is not particularly limited, and a usual heater, thermo module, hot air, etc. can be adopted.
Either a contact method or a non-contact method can be adopted. The heat treatment temperature does not have to be a particularly high temperature as long as it is a temperature at which the porous polymer layer is densified, and when the porous polymer layer is formed from polymer latex, the minimum temperature for forming a latex film. The above is sufficient. It is preferable that a label having a film is immediately produced by performing printing and heat treatment in one label writer, but it is possible to heat it separately with an iron after printing the label.

The transparent polymer film formed as a result has a protective effect of improving the water resistance and weather resistance of the label. Here, the term "transparent" means that characters (including figures) recorded on the ink receiving layer can be observed through the polymer film. It is preferably colorless, but may be colored for imparting a design property. The thickness of the polymer layer after densification is preferably 0.3 to 5 μm. If the thickness of the transparent polymer film is less than 0.3 μm, the effect of protecting the ink receiving layer may be insufficient, which is not preferable. When the thickness of the transparent polymer film is more than 5 μm, the protective effect does not increase further, and conversely the image quality is deteriorated due to the concealment of the polymer film, peeling of the polymer film and curling of the label occur. It is not preferable because it may occur.

[0031]

In the present invention, the transparent polymer film obtained by densifying the porous polymer film covers the ink receiving layer so that the dye fixed on the ink receiving layer allows oxygen, ozone, NO _{x in the} air to be _absorbed. It has the function of preventing the reaction with or the like or volatilization, and also shielding the ultraviolet rays.
Even if the base material is a material such as paper that allows air to permeate therethrough, the dye is more effectively fixed to the transparent polymer film side of the ink receiving layer, and therefore the same effect is exhibited. Further, the transparent polymer film covers and protects the ink receiving layer, whereby the environmental resistance such as scratch resistance, water resistance, solvent resistance, weather resistance and stain resistance of the label is improved.

The silica gel layer formed on the porous polymer layer not only protects the porous polymer layer before densification but also contributes to the improvement of scratch resistance after densification.

[0033]

【Example】

[Example 1] 100 g of an alumina sol having a solid content of 18% by weight synthesized by a method of hydrolyzing and peptizing aluminum alkoxide
And 32 g of a 6.2 wt% aqueous solution of polyvinyl alcohol were mixed to prepare a coating liquid. This coating liquid was applied onto a polyethylene terephthalate film (white film, thickness: 38 μm) using a die coater so that the coating amount after drying was 25 g / m ² . This was dried and then heat treated at 140 ° C. to form a porous boehmite layer.

On the boehmite layer, a PVC latex having a solid content of 10% by weight was applied using a die coater and dried at 60 ° C. After drying, a porous polymer layer having a thickness of 2 μm was formed. On this porous polymer layer, a silica sol coating solution containing silica particles having an average primary particle diameter of 20 nm and a silicon-containing polymer and having a solid content of 5% by weight is applied and dried so that the coating thickness after drying is 3 μm. And then 14
It was dried at 0 ° C.

Next, a pressure-sensitive adhesive layer is formed on the side where the boehmite layer and the porous polymer layer are not formed, and a thickness of 7 is formed thereon.
A 5 μm release paper was laminated. As a result, when the release paper is peeled off, a sheet that can be adhered to the adherend is obtained. This sheet was cut into a tape shape having a width of 15 mm and a length of 10 m and wound up to obtain a tape for a label writer.

This tape can be printed using an ink jet printer, and after printing, the porous polymer layer can be heated to 100 ° C. to form a transparent film. After that, it is cut into an appropriate length and the release paper is peeled off, so that the label can be attached to a desired place.

[Example 2] The SBR latex having a solid content of 5% by weight was applied to the boehmite layer on the white film formed in the same manner as in Example 1 by using a die coater to give a dry thickness of 1 µm.
And was dried at 90 ° C. A silica gel layer was formed on the thus obtained porous polymer layer in the same manner as in Example 1. This tape can be printed using an inkjet printer, and after printing, the porous polymer layer can be heated to 130 ° C. to form a transparent film. After that, it is cut into an appropriate length and the release paper is peeled off, so that the label can be attached to a desired place.

[0038]

The label writer tape of the present invention is capable of high-quality printing by the ink jet system, is excellent in quick-drying property and color development, and can be adapted to full-color printing.
Furthermore, by forming a film on the porous polymer layer after printing, a label having excellent environmental resistance such as scratch resistance, water resistance, weather resistance, solvent resistance, stain resistance, and the like can be produced.
Therefore, the obtained label has storage stability that maintains high image quality for a long period of time. It is particularly suitable for recording using a water-based ink.

Furthermore, the transparent porous polymer layer has the effect of increasing the gloss of the label. Even when the transparency of the ink receiving layer is low, the dense porous layer covers the ink receiving layer, so that printing with a higher color density becomes possible as compared with the case where there is no film.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a cross section of an example of a label writer tape of the present invention.

[Explanation of symbols]

 1: Tape-shaped substrate 2: Ink receiving layer 3: Porous polymer layer 4: Silica gel layer 5: Adhesive layer 6: Release paper

Claims (4)

[Claims] 1. A label writer having an ink receiving layer on a tape-shaped substrate, a porous polymer layer which can be made transparent by heating, and a silica gel layer further laminated thereon. tape. 2. The tape for a label writer according to claim 1, wherein the porous polymer layer is formed by coating and drying polymer latex. 3. The silica gel layer is formed by coating and drying silica sol and a binder.
Label writer tape. 4. The label writer tape according to claim 1, wherein the printing method is an inkjet method.