JP2002019256A - Plastic container printed by luminous ink and method for printing plastic container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic container capable of being identified not only in a bright place but also in a dark place by printing a surface of the container with a luminous ink. SOLUTION: A method for printing the plastic container comprises the step of printing the surface of the container with the luminous ink. The plastic container is printed with the luminous ink. The used luminous ink preferably contains, in the case of ultraviolet curing type, a photopolymerization initiator of 0 to 20 pts., a photosensitizer of 0 to 20 pts. and a luminous pigment of 1 to 50 pts. with respect to a vehicle of 100 pts. In the case of the ink of the ultraviolet curing type, the method also comprises the steps of, in the case of the ultraviolet curing type ink, printing a printing ink containing an ultraviolet curing type ink composition as a base, and then emitting the ultraviolet ray to the printing surface to cure the ultraviolet curable component of the ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container on which luminous ink is directly printed when displaying and decorating a plastic container, particularly a product name, a design, and the like, and a method for printing the plastic container.

[0002]

2. Description of the Related Art In many cases, product descriptions, product names, and the like are printed on a surface of a plastic container or the like with ink. By the way, the luminous ink emits so-called afterglow, which has the property of absorbing and accumulating light energy such as sunlight, electric lights, etc., and releasing the light gradually, among inorganic fluorescent substances. This is an ink containing a pigment component. In this case, light absorption-accumulation-emission can be repeated any number of times.

[0003]

Recently, there is a demand for plastic containers to be differentiated from others and to add commercial value, and in particular, functional printing is required.
The present invention provides a plastic container that performs printing with luminous ink on the surface of a plastic container or on the surface of a plastic container so that printed characters can be distinguished not only in a bright place but also in a dark place. The purpose is to do.

[0004]

Means for Solving the Problems The present invention relates to a plastic container on which luminous ink is directly printed and a printing method thereof.

[0005] As the luminous ink, any kind of ink can be used, but it is particularly preferable to use an ultraviolet curable ink.
In addition, the ink of the present invention can be separated from a container and a printed portion after collection, for example, as described in Japanese Patent No. 2989.
735 and Japanese Patent No. 2999334.

[0006] Luminescent ink emits light in a dark place for the first time after being irradiated with sunlight, electric light, or the like. Therefore, the intensity of irradiation light, the irradiation time, the thickness of an ink film, and the like, and the afterglow are deep. Have a relationship. Luminescent pigments are inferior in water resistance and durability, and therefore are not preferred for applications exposed to strong direct sunlight, wind and rain. Further, since the water resistance is not as strong as that of a general ink, it is preferable to overlay the transparent clear when the ink is used in a place having a large amount of water. The phosphorescent ink is preferably printed by screen printing, but the screen mesh is selected in consideration of the particle size of the phosphorescent pigment, ink viscosity, printing speed, etc., and the phosphorescent pigment is destroyed during the printing process,
It is preferred that the holes in the screen are not clogged. As a means for performing screen printing of characters, patterns, figures, and the like on a plastic container with luminous ink, a silk screen plate of about 100 to 420 mesh is particularly preferable.

The luminous ink used in the present invention is
In the case of an ultraviolet curing type, 0 to 20 parts of a photopolymerization initiator, 0 to 20 parts of a photosensitizer, and 1 part of a luminous pigment are added to 100 parts of a vehicle.
Particularly preferred is 50 parts by weight.

In the printing method of the present invention, printing may be performed without treating the surface of the plastic container prior to printing. However, the surface of the plastic container may be subjected to a treatment such as a frame or corona discharge, or an anchor coat treatment. You may do.

The material of the plastic container is not particularly limited, and many kinds of resins such as polyvinyl chloride, polystyrene, acryl, polyester and polyolefin are used. The plastic container according to the present invention may contain additives such as a colorant, an ultraviolet absorber, and an antistatic agent at an appropriate ratio, if necessary.

In the case where the luminous ink used in the present invention is an ultraviolet curable ink, the printing method is to perform printing with a printing ink based on the ultraviolet curable ink composition when the ink is an ultraviolet curable ink. Thereafter, the printing surface is irradiated with ultraviolet rays to cure the ultraviolet curable components in the printing ink.

The plastic container of the present invention can be obtained by hollow molding, biaxial stretch blow molding, injection molding, or the like.

When the luminous ink used in the present invention is of an ultraviolet curing type, many photopolymerization initiators are known. For example, benzophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone can be used. 2-methyl * (4-methylthiophenyl) -2-morpholinopropan-1-one;
Benzoin alkyl ether, benzyl, benzyl dimethyl ketal, camphorquinone, 2-ethylanthraquinone, methyl benzoylbenzoate, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2,4-diethylthioxan Son, methylphenylglyoxylate, benzoylphosphine oxide, 1-trimethylbenzoyldiphenylphosphine oxide and the like. Examples of the photosensitizer include triethanolamine, methyldiethanolamine, triisopropanolamine, 4,4
'-Diethylaminobenzophenone, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid-n-
Butoxyethyl and isoamyl 4-dimethylaminobenzoate.

Although the photopolymerization initiator can be used alone, it is often used in combination with a photosensitizer to improve photopolymerizability.
The most suitable photopolymerization initiator and photosensitizer are selected depending on the ink vehicle component used. The criterion is determined depending on the purpose, such as the curing speed, the presence or absence of coloring at the time of curing, the presence or absence of a pigment, and the intensity of odor after curing. The amount used is relative to the ink vehicle.
Although a photopolymerization initiator and a photosensitizer can be used in amounts of 1 to 20 parts, respectively, when used in a large amount, the curing speed is fast but the molecular weight does not increase, the strength of the cured film is lowered, and the odor is also not strong. The most desirable use range is 2 to 10 parts as a combined amount of both. In that case, the usage ratio of the photopolymerization initiator and the photosensitizer depends on the type and the component ratio of the vehicle component, and in the case of an ink to which a coloring pigment described below is added,
It is necessary to change the ratio of the two depending on the ultraviolet absorbing power specific to the pigment, and the ratio is not uniform. Pigments are roughly classified into organic pigments and inorganic pigments in terms of chemical composition, but are also classified into colored pigments and non-colored pigments (enrichment pigments) in terms of application. When it comes to UV curing, the category of application is more important.

In the luminous ink, each particle of the pigment contained therein emits light and receives stimulating light such as sunlight or electric light.
It is particularly preferable to use a colorless and transparent resin with little burning as a resin varnish (coloring agent) for the ink. Further, since there are various uses and printing media, it is necessary to select a coloring agent each time. The phosphorescent ink can be specially colored with a fluorescent pigment or the like, but the brightness may be significantly reduced. A color pigment may be added to the phosphorescent ink within a range that does not reduce the luminance in a dark place. Among the coloring pigments, inorganic pigments include white pigments such as lead white, zinc white, zinc sulfide, and titanium dioxide; blue pigments such as ultramarine blue, dark blue, and cobalt blue; chromium oxide, pyridian, and green pigments such as chrome green; Yellow to red pigments such as graphite, titanium yellow, yellow iron oxide, molybdate orange, cadmium pigment, red iron oxide, black pigments such as iron black, titanium black and carbon black, metal pigments such as aluminum powder and bronze, and mica And other pearl pigments. However, there are many inorganic pigments that must be avoided from the viewpoint of safety and hygiene, and harmless ones are selected from the above. As the organic pigment, any of monoazo, disazo, condensed azo, indanthrone, indigo, thioindigo, quinacridone, phthalocyanine, dioxazine, isoindolinone, and pyrrolopyrrole can be used, and ultraviolet irradiation can be used. In particular, it is desirable to select and use a pigment having low light fading and high light fastness in accordance with the curing method described above.

In order to obtain good color development, a large amount of pigment is blended with a vehicle in which a small amount of a pigment dispersant is added, and a pulverization pressure is physically applied by utilizing the viscosity improvement caused by the oil absorption. An easy state is created, and sufficient kneading is performed by a general medium dispersing machine such as a ball mill or a roll mill in the color material industry. The thus obtained high-concentration pigment dispersion (toner) is replenished and adjusted with a deficient vehicle so as to obtain a predetermined pigment concentration at the time of ink formulation.

In the ink composition used in the present invention, the properties of the printing ink, such as viscosity, fluidity, and thixotropy, are maintained, the ink buildup is maintained and increased, shrinkage buffering during curing, surface matting, and slip property imparting. Various non-colored pigments (enrichment pigments) can be used for the purpose of improving the strength of the film.
Commonly used extender pigments include talc, kaolin,
Silica, precipitated barium sulfate, precipitated calcium carbonate,
Inorganic pigments such as alumina white and white carbon,
Waxes such as polyethylene wax, polypropylene wax, and polyfluorinated polyethylene wax, and fine powders of artificial and / or natural polymers such as polyamide resin, polyimide resin, melamine resin, benzoguanamine resin, cellulose, and collagen. The amount of these can be freely determined according to the purpose. In the ink composition of the present invention, in order to adjust the finished state of the cured film,
Leveling and / or antifoaming agents can be added.
Among these, various leveling agents and defoaming agents generally sold in the market are used after confirming by a test those which are well compatible with the vehicle component and can obtain surface smoothness. The type and amount used do not limit the content of the ink composition of the present invention, and may be appropriately determined. Usually, the total amount of the leveling agent and / or the antifoaming agent is 0.5 to 0.5% of the total ink amount. 5% by weight are used.

In addition, if necessary, an ultraviolet absorber, a wetting improver, an antioxidant and the like can be used. The phosphorescent ink used in the present invention thus produced is mainly used for screen printing, but when adjusted to a lower viscosity using an organic solvent, for example, flexographic printing and gravure printing, etc. Can also be used satisfactorily as an ink in the printing method.

As the luminous ink, conventionally known ones are used. As the phosphorescent pigment, CaS / Bi, CaSrS / B
i, ZnS / Cu, ZnCdS / Cu, ZnCdS / C
u, ZnCdS / Cu or the like is used. The phosphorescent pigment has a larger particle size than the general pigment and is about 5 μm to 20 μm.

When the luminous ink used in the present invention is of an ultraviolet curing type, the irradiation of the printing surface with ultraviolet rays is usually performed by a high-pressure mercury lamp or a metal halide lamp having a wavelength of about 200 to 450 nm. And the integrated amount of ultraviolet light is 100 to 500 mj / c
m ² is preferred.

[0020]

EXAMPLE 1 200 g of calcium sulfide phosphorescent ink having a particle size of 15 m.mu.
Using a meshed Tetron (registered trademark) screen plate, screen printing was performed on an untreated polyethylene terephthalate container for soy sauce, and a 120 W / cm metal halide lamp was used to irradiate 200 mj / cm ^{2 of} integrated ultraviolet light,
A cured film was obtained. The container, once illuminated, could be identified even in dark places.

Example 2 The same luminous ink as in Example 1 was screen-printed on an untreated polyethylene terephthalate container for sake using a 150-mesh tetron screen plate to give 120 W / c.
200m integrated UV light with m metal halide lamp
Irradiated at j / cm ² to obtain a cured film. The container, once illuminated, could be identified even in dark places.

Example 3 The same phosphorescent ink as in Example 1 was screen-printed on an untreated polyethylene phthalate container for dishwashing detergent using a 250-mesh Tetron screen plate to give 120 W / c.
200m integrated UV light with m metal halide lamp
Irradiated at j / cm ² to obtain a cured film. The container, once illuminated, could be identified even in dark places.

[0023]

The printing of the plastic container of the present invention can be distinguished not only in a bright place but also in a dark place as compared with printing with an ink containing a general coloring pigment, so that the added value is increased and the printed matter is increased. Effect can be further expanded. In addition, since the luminous ink is printed on the container, for example, a container for toiletries and a container for emergency equipment stored in a dark place can be identified even in a dark place.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 5, 2000 (2007.5.5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2H113 AA01 AA02 AA03 AA06 BA10 BA13 BB07 BB21 BC00 BC09 CA25 CA31 CA32 DA05 DA10 DA47 DA53 DA57 EA10 EA15 FA43 3E062 AC02 DA02 DA09 4J039 AD20 BA18 BA31 BC12 BC16 BC35 BC56 GA27 EA06

Claims (6)

[Claims] 1. A method for printing a plastic container, comprising printing with a luminous ink. 2. A printing method for a plastic container, wherein the printing is screen printing. 3. The method according to claim 2, wherein the screen has a mesh size of 100 to 420 mesh. 4. The method for printing a plastic container according to claim 1, wherein the phosphorescent ink is an ultraviolet curable ink. 5. The luminous ink comprises 0 to 20 parts of a photopolymerization initiator, 0 to 20 parts of a photosensitizer, and 1 to 50 parts of a luminous pigment based on 100 parts of a vehicle. ~
5. The method for printing a plastic container according to any one of 4. 6. A plastic container on which a luminous ink is printed by the method according to claim 1.