JPH09104163A - Tape for label writer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape for a label writer adapted to an ink jet system and excellent in environmental or strength such as scratch resistance, water resistance or weatherability and having storage stability preventing fading over a long time and keeping high image quality. SOLUTION: An ink receiving layer composed of a boehmite porous layer and a polymeric porous layer containing one or more kinds of a compd. selected from among a group consisting of dithiocarbamate, thiocyanate and a hindered amine formed on a base material tape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape for a label writer, which can easily produce a high quality label by an inkjet method.

[0002]

2. Description of the Related Art A generally known tape for label writer is currently employing a thermal transfer system. At present, the colors of tapes and print ribbons are specified, and in the future, full-colorization by which the user selects the color will be required. But,
In the case of realizing full color in the future, if the thermal transfer method is used, the price of the ink ribbon will be high and the cost will be high, and further, the environment resistance and strength such as scratch resistance and solvent resistance will not be sufficient.

On the other hand, in order to easily realize full color, an ink jet system is naturally considered from the viewpoint of cost and sharpness of image quality. However, in the case of the ink jet system, ink bleeding, tape scratch resistance, water resistance, and other environmental resistance are also considered. Includes problems that need to be improved. Especially when used outdoors, it may be exposed to rain, and when it is used for tableware or the like, it may be exposed to water or detergent. The ink receiving layer alone cannot withstand these use environments.

Further, in the case of the ink jet system, the one using a dye as the ink may be discolored over time during storage after printing or during use in a normal environment.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet type label writer tape which realizes clear full-color printing with a characteristic of not fading even after long-term storage.

[0006]

According to the present invention, a base tape is provided with an ink receiving layer composed of a boehmite porous layer, on which a dense transparent protective layer can be formed by heating. An ink jet type label writer tape having a molecular porous layer, comprising a boehmite porous layer or a polymer porous layer, dithiocarbamate,
Provided is a tape for label writer containing one or more compounds selected from the group consisting of thiocyanate and hindered amine.

The present invention also provides a label having a boehmite porous layer having an ink fixed thereon on a base tape, and a transparent protective layer thereon, wherein the boehmite porous layer or the transparent resin layer comprises dithiocarbamine. Provided is a label containing one or more compounds selected from the group consisting of acid salts, thiocyanates and hindered amines.

In the present invention, dithiocarbamate,
One or more compounds selected from the group consisting of thiocyanates and hindered amines act as an anti-fading agent for the ink, and can delay the fading speed of the ink to a practically sufficient degree.

When the transparent resin layer in the label of the present invention is coated with the boehmite porous layer, the dye in the ink comes into contact with water, reacts with oxygen, ozone, NO _x in the air, or volatilizes. It has a function to prevent Even if the substrate is permeable like paper, recording is performed from the side opposite to the substrate of the boehmite porous layer, so the dye is more present on the transparent resin side of the boehmite porous layer. It works as well.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The base material is not particularly limited, and various materials can be used. Specifically, various plastics such as polyester such as polyethylene terephthalate, polycarbonate, fluororesin such as ETFE, and papers can be used. For the purpose of improving the adhesive strength of the ink receiving layer, these substrates can be subjected to corona discharge treatment, undercoating, or the like. Transparent material such as transparent plastic film as the base material,
Alternatively, any opaque film or paper such as opaque film containing a white or other color pigment can be used.

The boehmite porous layer is made of boehmite (Al
₂ O ₃ · nH ₂ O, n = 1 to 1.5) and a composition containing a binder are preferable. Boehmite is preferable because it has good absorptivity and adsorbs the dye well, so that a clear recorded matter having a high color density can be obtained.

The pore structure of the boehmite porous layer has a radius of 1
Consisting of pores of ˜15 nm and pore volume of 0.3 to 1.0
The case of cc / g is preferable because it has sufficient absorbability and transparency. At this time, if the substrate is transparent, a transparent tape can be obtained. If the substrate is opaque, a tape capable of recording with high color density can be obtained. It is further preferable that the average pore radius of the boehmite porous layer is 3 to 10 nm. The pore size distribution is measured by the nitrogen adsorption / desorption method.

In order to form a boehmite porous layer having a pore structure as described above, a binder is preferably added to alumina sol to prepare a coating solution, which is a die coater, roll coater, air knife coater, blade coater, bar coater, Apply on a substrate using a comma coater, etc.
It is preferable to adopt a drying method.

As the binder, organic substances such as starch and modified products thereof, polyvinyl alcohol and modified products thereof, SBR latex, NBR latex, hydroxyl cellulose and polyvinylpyrrolidone can be preferably used. If the amount of the binder used is small, the strength of the boehmite porous layer may be insufficient, and conversely, if it is too large, the amount of ink absorbed and the amount of the dye carried may be low. About wt% is preferable.

If the thickness of the boehmite porous layer is too thin, the dye cannot be sufficiently supported and the color density becomes low, which is not preferable. On the other hand, if it is too thick, the strength of the porous layer will be reduced, or the transparency will be reduced and the texture will be impaired, such being undesirable. The optimum thickness of the porous layer is 1 to 50 μm.

In the present invention, a label having a transparent protective layer formed on an ink receiving layer composed of a boehmite porous layer can be obtained. The term "transparent" as used herein means that the image formed on the ink receiving layer can be observed through the transparent protective layer. It is preferably colorless, but it may be colored in order to impart a design property.

As a means for forming the transparent protective layer, a polymer porous layer is previously formed on the boehmite porous layer before recording by ink jet, and an image is formed on the boehmite porous layer through the polymer porous layer by an ink jet printer. After the formation, a method is preferred in which the polymer porous layer is heat-treated to form a film, and a transparent resin film is formed on the boehmite porous layer.

The polymer porous layer which can be converted into the transparent protective layer is preferably formed by coating polymer latex on the boehmite porous layer and drying. The polymer latex is preferably a thermoplastic polymer latex, for example, PVC latex, SBR latex,
NBR latex or the like can be used alone or in combination.

The polymer latex has an average particle size of 0.05.
.About.0.5 .mu.m is preferred. When the average particle size of the polymer latex is less than 0.05 μm, a porous layer having good ink absorbability and ink permeability is not formed, and the ink is not sufficiently fixed on the boehmite porous layer, so that a desired image is obtained. Is not preferable because it cannot be formed. If the average particle size of the polymer latex exceeds 0.5 μm, the dots of the ink become non-uniform and the image quality is deteriorated, which is not preferable.
The more preferable average particle diameter of the polymer latex is 0.08
０．３0.3 μm.

The minimum temperature for forming a polymer latex film is
It is preferably in the range of 50 to 150 ° C. If the minimum film formation temperature is less than 50 ° C, it is difficult to form a dense resin film when the polymer latex is applied onto the boehmite porous layer and dried to form a porous resin layer. It is not preferable since it takes a long time to dry and is not industrial. When the film forming temperature exceeds 150 ° C., it is necessary to raise the heat treatment temperature after the image formation, and there are problems of decomposition and coloring of the resin and heat denaturation of the base material or the dye, which is not preferable. A more preferable film formation temperature is 65 to 130 ° C.

By coating the coating solution comprising this polymer latex on the boehmite porous layer and drying,
A polymeric porous layer can be formed. The solid content of the latex is not particularly limited, but a latex having a solid content of 2.5 to 50% by weight can be appropriately used. It should be noted that other polymer component having a binder action may be added to the polymer latex.

The method of applying the 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. Drying is preferably performed at a temperature not higher than the minimum temperature for forming a film.

The thickness of the polymer porous layer is preferably 0.3 to 5 μm. When the thickness of the polymer porous layer is less than 0.3 μm, the effects of environmental resistance such as water resistance, scratch resistance, and weather resistance when formed into a film are not sufficient, and the thickness exceeds 5 μm Is not preferable because the ink absorptivity is reduced, or the image quality is deteriorated when a crack is formed to form a film, and the effects of environmental resistance such as water resistance, scratch resistance, and weather resistance cannot be obtained. The more preferable thickness of the polymer porous layer is 0.
It is 5 to 3 μm.

In the tape for label writer of the present invention, one or more compounds selected from the group consisting of dithiocarbamate, thiocyanate and hindered amine are provided in either or both of the polymer porous layer and the ink receiving layer. Is contained. These compounds function as an anti-fading agent and prevent the fading of the ink during storage after printing. These dithiocarbamate salts, thiocyanate salts and hindered amines each have an excellent anti-fading effect even when used alone, but even more excellent effects can be obtained by using a plurality of these compounds.

The dithiocarbamate salt is preferably potassium dimethyldithiocarbamate, sodium diethyldithiocarbamate or the like, and the thiocyanate salt is preferably sodium thiocyanate, potassium thiocyanate or the like.

As a method for applying one or more compounds selected from the group consisting of dithiocarbamate, thiocyanate and hindered amine (hereinafter referred to as the present anti-fading agent) to the polymer porous layer or the boehmite porous layer. The method of applying a solution obtained by dissolving the anti-fading agent in a suitable solvent by a dipping method or a spray method, or pre-mixing the anti-fading agent with a raw material for forming a boehmite porous layer or a polymer porous layer. A method of putting it in can also be adopted.

When the polymer porous layer contains the anti-fading agent, the transparent protective layer containing the anti-fading agent is formed by heating after recording by an ink jet method to form a transparent protective layer. .

The content of the anti-fading agent is preferably 0.01 to 10% by weight based on the weight of the boehmite porous layer. The content of the anti-fading agent is 0.01
If the amount is less than 10% by weight, the effect of the present invention is not sufficiently exhibited and the fading of the ink may occur, which is not preferable. If the content of the present anti-fading agent exceeds 10% by weight, the absorptivity of the boehmite porous layer may be impaired, which is not preferable. The more preferable content of the present anti-fading agent is 0.1 to 1% by weight based on the weight of the boehmite porous layer.

By providing a release paper (separator) on the back surface of the tape for label writer thus formed, that is, on the side where the boehmite porous layer and the polymer porous layer are not formed, via an adhesive material. If the separator is peeled off, a label writer tape which can be adhered to an adherend can be obtained.

In practice, a boehmite porous layer, a polymer porous layer, or a separator as required, is laminated using a base material wider than the desired tape width, and the width is slit to 5 to 50 mm and the length is increased. A label writer tape can be obtained by cutting the roll to a length that can be accommodated in a label writer cartridge within a range of 3 to 15 m and forming a roll. The thickness of the separator is preferably 10 to 200 μm. If the thickness is less than 10 μm, the separator is thin and difficult to peel off. If the thickness exceeds 200 μm, the total thickness of the label writer tape becomes too thick, and the diameter of the roll becomes large when it is formed into a roll, which is not preferable.

When an image is formed on the tape for label writer thus formed from above the polymer porous layer by an ink jet printer, the ink reaches the boehmite porous layer through the polymer porous layer. Since boehmite has a high adsorptivity for the dye in the ink, an image is formed substantially on the part of the boehmite porous layer. After that, when the polymeric porous layer is heat-treated to form a transparent film, it acts as a protective layer for the dye fixed on the boehmite porous layer. The heat treatment may be at least the latex film formation minimum temperature, and the heating means is not particularly limited, and hot air, iron, ordinary heating heater, thermo module, etc. are used, and either contact or non-contact method is used. Is also possible.

The recorded matter of the present invention is particularly suitable for a tape for an ink jet type label writer, but is also suitable for a tack sheet for an ink jet printer. Further, it can be applied to other recording methods for recording using a dye.

[0033]

【Example】

Example 1 A coating solution was prepared by mixing 100 g of an alumina sol having a solid content of 18% by weight synthesized by the hydrolysis / peptization method of aluminum alkoxide and 32 g of a 6.2% by weight aqueous solution of polyvinyl alcohol. This coating liquid was applied onto a substrate made of a polyethylene terephthalate film (white film, 38 μm thick) 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 boehmite porous layer.

On the boehmite porous layer, a solid content of 10
Using a die coater, a mixture of a PVC latex of 1% by weight and an aqueous solution of sodium thiocyanate (solid content weight ratio: 8: 2) has a thickness of 2 μm of PVC latex when dried.
It was applied so that the weight of sodium thiocyanate was 0.25 g, and dried at 60 ° C. to form a polymer porous layer.

Next, a separating paper (separator) having a thickness of 75 μm is provided on the back surface of the base material, that is, the side on which the boehmite porous layer or the polymer porous layer is not formed, with an adhesive material interposed therebetween. If it is peeled off, it can be bonded to the object to be bonded, and it is slit to a width of 15 mm and a length of 10 m.
The tape for label writer was obtained by cutting into a roll shape.

An image is formed on this tape for label writer using an ink jet printer, and then heat-treated with a heater (film surface temperature 100 ° C.) to form a label on which a porous polymer film is coated to form a transparent protective layer. Obtained.

Example 2 A mixture of an SBR latex having a solid content of 5% by weight and an aqueous solution of thiocyanic acid (solid content weight ratio, on a boehmite porous layer).
8: 2), the thickness when dried using a die coater is 2μ.
A tape for a label writer was obtained in the same manner as in Example 1 except that m and sodium thiocyanate were applied so that the weight thereof was 0.25 g, and the polymer porous layer was formed by drying at 60 ° C.

An image is formed on the tape for label writer using an ink jet printer, and then heat-treated with a heater (film surface temperature 130 ° C.) to form a label on which a polymer porous film is coated and a transparent protective layer is formed. Obtained.

Weather resistance test The labels obtained in Examples 1 and 2 and the labels prepared in the same manner as in Example 1 except that sodium thiocyanate was not used were exposed to air at room temperature for 100 days. And the label of Example 2 showed no fading,
The label without sodium thiocyanate showed some discoloration.

[0040]

INDUSTRIAL APPLICABILITY The tape for a label writer of the present invention can form a high quality image by an ink jet system and can be formed in full color. The obtained label has an ink receiving layer excellent in quick-drying property and color development, and is also excellent in environment resistance and strength such as scratch resistance, water resistance and weather resistance, and maintains fading prevention and high image quality for a long time. Has storage stability. It is particularly suitable for recording using a water-based ink.

Claims (2)

[Claims] 1. An ink jet system having an ink receiving layer composed of a boehmite porous layer on a base tape, and a polymer porous layer on which a dense transparent protective layer can be formed by heating. A label writer tape, comprising a boehmite porous layer or a polymer porous layer and one or more compounds selected from the group consisting of dithiocarbamate, thiocyanate and hindered amine. 2. A label having a boehmite porous layer on which ink is fixed on a base tape, and a transparent protective layer thereon, the boehmite porous layer or the transparent resin layer comprising:
A label containing one or more compounds selected from the group consisting of dithiocarbamates, thiocyanates and hindered amines.