JP6912897B2 - Manufacturing method of aluminum printed matter - Google Patents

Description

The present invention relates to a method for producing an aluminum material printed matter and a method for printing an aluminum material.

As a method of coloring and printing characters and patterns on an aluminum material, a photosensitive liquid is applied to the surface of an aluminum material (hereinafter referred to as "aluminum material") having an oxide film formed on the surface to form a mask, and a photoprinting film is used. The light-irradiated part is cured by irradiating only the uncolored part with light, and the uncured part is washed away. A method is known in which a portion is polished and removed, pores on the surface of an aluminum material are closed (sealing), and printing is performed.

As the photosensitive liquid used in the above method, a gelatin-based solution is widely used, and in particular, a gelatin dichromate solution used for collotype printing is widely used because of its high resolution, but there is a concern about safety problems. Will be done.

Further, Patent Document 1 describes a method for producing a colored aluminum material, which comprises a mask forming step, a coloring step, and a mask peeling step, and in the mask forming step, a mask is formed by an ink jet method. One of the features of the disclosure is that an acrylic ultraviolet curable ink is used as the mask forming liquid.

Japanese Unexamined Patent Publication No. 2014-227592

According to Patent Document 1, a stripping solution such as IPA (isopropyl alcohol) is used in the mask stripping step after the coloring step, but in this mask stripping step, when the mask is to be stripped with a stripping solution such as IPA, it is particularly oily. With dyes, the dye that has entered the pores on the surface of the aluminum material is washed out or melted out, so it is necessary to seal the holes before peeling off the mask. That is, there is a problem that one process is added. In addition, Patent Document 1 does not describe anything about the sealing after the coloring step. Further, if the film thickness of the mask is large, not only the peeling becomes difficult but also the printing resolution is lowered.

Therefore, an object of the present invention is to provide a method for producing an aluminum material printed matter, which is highly safe, efficient, and clearly colored and printed on an aluminum material, and a printing method thereof.

As a result of diligent studies on the printed matter of aluminum material, the present inventors made the thickness of the mask thinner because the mask was not eroded by adding water to the solvent that dissolves the oil dye when coloring and printing the non-mask area. The present invention has been completed by finding that the mask can be easily peeled off in the next step and the printing resolution is improved by making the mask thinner.

That is, the present invention
(1) A method for manufacturing aluminum printed matter.
A mask forming step of masking a preset area on the surface of an aluminum material to form a mask pattern,
A coloring step of coloring a non-masked area other than the mask pattern with a coloring material, and
A mask removing step of removing the mask pattern and
Including
A oily dye the coloring material is dissolved in a water-containing organic solvent,
A method for producing a printed matter, wherein the mask thickness of the mask pattern is 0.5 μm or more and 7 μm or less.
(2) The method for producing an aluminum printed matter according to (1), wherein the mask pattern is formed by an inkjet method using an ultraviolet curable ink.
(3) The method of manufacturing an aluminum material printed matter to (2) described as comprising the previous SL ultraviolet curable ink is at least one selected from organic pigments and dyes,
(4) The method for producing an aluminum printed matter according to any one of (1) to (3), wherein the mask removal in the mask removing step is removal by polishing.
(5) A printing method for aluminum materials
A mask forming step of masking a preset area on the surface of an aluminum material to form a mask pattern,
A coloring step of coloring a non-masked area other than the mask pattern with a coloring material, and
A mask removing step of removing the mask pattern and
Including
A oily dye the coloring material is dissolved in a water-containing organic solvent,
A method for printing an aluminum material, wherein the mask thickness of the mask pattern is 0.5 μm or more and 7 μm or less.
(6) The method for printing an aluminum material according to (5), wherein the mask pattern is formed by an inkjet method using an ultraviolet curable ink.
(7) The method for printing an aluminum material according to (5) or (6), wherein the mask removal in the mask removing step is removal by polishing.
Is.

According to the present invention, by using an oil-based dye dissolved in a water-containing organic solvent in the coloring step, it is possible to invade any type of mask such as a photocurable mask of gelatin dichromate and an acrylic ultraviolet curable mask. Therefore, the thickness of the mask can be reduced. As a result, the mask can be easily peeled off and the print resolution is improved.

Hereinafter, embodiments for carrying out the present invention will be described in detail. It should be noted that the present embodiment is only one embodiment for carrying out the present invention, and the present invention is not limited to the present embodiment, and various modified embodiments are provided without departing from the gist of the present invention. It is possible.

The method for producing an aluminum printed matter of the present invention is:
This is a method for manufacturing aluminum printed matter.
A mask forming step of masking a preset area on the surface of an aluminum material to form a mask pattern,
A coloring step of coloring a non-masked area other than the mask pattern with a coloring material, and
A mask removing step of removing the mask pattern and
Including
An oil dye in which the colorant is dissolved in a water-containing organic solvent,
It is characterized by being.

The aluminum material used in the present invention is an aluminum member in which an anodic oxide film is formed at least in a region to be colored in the coloring process. This aluminum material may be aluminum that has been anodized (anodized). In this treatment, the aluminum material is preferably oxidized using an acidic solution such as sulfuric acid. Pore made of aluminum oxide is formed on the surface of the aluminum material treated in this way. In printing of an aluminum material, the coloring material penetrates into the pores and is colored.

In the mask forming step of the present invention, after applying a gelatin dichromate solution to an aluminum material, the mask portion is photocured and the areas other than the cured portion are washed away. An ultraviolet curable ink is printed on the mask portion and cured by ultraviolet rays. A mask pattern is formed by a method such as ,, but in consideration of the environment, a method of printing using an ultraviolet curable ink is preferable to a method using gelatin dichromate. Further, also in the mask forming method by printing, printing by the inkjet method is more preferable because a plate is not required and the environmental load is further reduced such that the amount of ink used is small.

The film thickness of the mask thus produced is 0.5 μm or more and 7 μm or less. If it is less than 0.5 μm, defects may occur in the mask regardless of which mask forming method is used, and if it exceeds 7 μm, not only the peeling becomes difficult but also the accuracy of the mask pattern deteriorates, which is not preferable. In the present invention, the film thickness of the mask is a value obtained by calculating from the coating amount and the solid content of the ink, where 1 is the specific gravity of the ink and its solid content.

In the case of mask formation by an inkjet method using an ultraviolet curable ink, the surface tension of the ultraviolet curable ink is preferably 15 mN / m or more and 22 mN / m or less at 25 ° C. by the plate method. If the surface tension is to be less than 15 mN / m, a large amount of fluorine-based solvent must be used, and as a result, the compatibility with other ink components is lowered, and if it exceeds 22 mN / m, the smoothness of the mask becomes insufficient. , It is not preferable because pinholes are generated.

The viscosity of the ultraviolet curable ink is preferably 25 ° C., 4 mPa · sec or more and 12.5 mPa · sec or less using a cone plate type viscometer. If it is less than 4 mPa · sec, the viscosity is too low, and it is not suitable for printing by the inkjet method. If it exceeds 12.5 mPa · sec, the discharge stability is lacking, and even if the viscosity is lowered by heating, if the solvent is contained, the discharge may become impossible due to the evaporation of the solvent.

By setting the surface tension and viscosity of the ultraviolet curable ink within the above ranges, the film thickness can be easily adjusted to a preferable level as a mask pattern. In addition, since it has excellent wettability to the surface of the aluminum material, it adheres to the surface of the aluminum material, fulfills a sufficient function as a mask in the subsequent coloring process, and has an appropriate adhesion in the mask removing process. It is considered that the mask can be easily removed by polishing or the like, coupled with the fact that the mask is thin.

One of the features of the UV curable ink is that it contains at least one selected from organic pigments and dyes in order to make the masked area easily visible. These organic pigments and dyes have good dispersibility in ink and are not selected as long as they do not cause any problem in inkjet ejection. The content may also be a concentration that can be visually recognized (for example, 1% by mass or less).

The volatile component of the ultraviolet curable ink used in the present invention, such as an organic solvent, is preferably 30% by mass or more. If the volatile component is less than 30% by mass, leveling will be insufficient and pinholes or the like will occur in the mask region when printing to the set film thickness of the mask pattern, which is not preferable.

A fluorine-based compound can be used in the ultraviolet curable ink in order to more easily adjust the target surface tension and viscosity. Examples of the fluorine-based compound include those having solvent solubility among Megafvck manufactured by DIC, Surfron manufactured by AGC Seichemical, and Futergent manufactured by Neos. Further, as the fluorine-based compound, a fluorine-based solvent such as 3M Japan's NOVEC series and Asahi Glass's Asahiclean series can be used.

The polymerizable compound used in the ultraviolet curable ink is not selected as long as it can be radically polymerized by irradiation with ultraviolet rays, but an acrylic monomer or oligomer can be preferably used.

The photopolymerization initiator used in the ultraviolet curable ink is not selected as long as it is a compound capable of generating a substance that initiates radical polymerization by irradiation with ultraviolet rays, but 2,4,6-trimethylbenzoindiphenylphos. Acylphosphine oxide-based initiators such as finoxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide are preferably used. The amount of these photopolymerization initiators added is 1 to 15% by mass in the ultraviolet curable ink.

The ultraviolet curable ink may contain a photosensitizer, and thioxanthone-based sensitizers such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone are preferably used. The amount of these photosensitizers added is 0.01 to 10% by mass in the ultraviolet curable ink.

The ultraviolet curable ink may be used as a non-reactive compound, an inorganic filler, an organic filler, a coupling agent, a tackifier, a defoaming agent, a leveling agent, a plasticizer, an antioxidant, or a polymerization agent, if necessary. It may contain a banning agent, an ultraviolet absorber, a flame retardant, and the like. Any known and commonly used material can be used without limitation as long as its characteristics are not impaired.

Following the mask forming step, the non-masked region other than the mask pattern is colored with a coloring material. As the coloring material, it is preferable to use an oil dye dissolved in a water-containing organic solvent. By including water in the solvent of the oil-based dye, erosion of the mask by the oil-based dye or the contained solvent can be suppressed, so that the film thickness of the mask can be reduced, and as a result, the mask can be easily peeled off and the printing resolution can be improved. improves.

In the printing of an aluminum material, the dye molecules are colored by entering the pores having a diameter of about 10 to 30 nm formed on the surface of the aluminum material, so that the printing density changes depending on the number of holes per area of the printed portion. Therefore, when the number of holes is constant, it is necessary to increase the number of dye molecules that enter one hole in order to increase the print density, but the water-based dye has an affinity with the pores on the surface of the aluminum material as compared with the oil-based dye. It is considered that the print density does not increase because the property is low and cannot penetrate into the pores. Further, when a pigment is used as a coloring material, the pores must be enlarged, so that not only the treatment conditions of the aluminum surface need to be changed, but also the resolution is lowered.

The oil-based dye dissolved in the water-containing organic solvent is used for coloring by a method such as dipping, coating, screen printing, or printing by an inkjet method, but coating is preferable in consideration of reducing the amount of the coloring material used. Further, in order to permeate and fix the coloring material in the pores formed on the surface of the aluminum material, it is preferable to rub the surface with a cloth or the like at the time of coating or after coating.

The hydrous organic solvent means a solvent in which water is dissolved in an organic solvent in an amount of 5% by mass or more and 30% by mass or less, and the organic solvent can dissolve water at a concentration of 5% by mass or more. Things, ketones, alcohols and the like. Examples of the ketones include acetone and ethyl methyl ketone, and examples of the alcohols include aliphatic monoalcohols such as ethanol, isopropyl alcohol and n-butanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether and diethylene glycol. Glycol ethers such as monobutyl ether and propylene glycol monomethyl ether can be exemplified. These ketones and alcohols may be used as a mixture thereof. Since the solubility in the water-containing organic solvent naturally changes depending on the type of the oil-based dye, it is necessary to appropriately determine the blending composition in each case.

Prior to the coloring step, a step of etching with an aqueous sodium hydroxide solution or an iron chloride etching solution may be added mainly for the purpose of imparting design.

The mask is removed by a mask removing step following the coloring step. To remove the mask, use a stripping solution such as isopropyl alcohol) or polish (physically remove), but if the stripping solution is used, there is a problem that the colored part also dissolves, so calcium carbonate, It is preferable that the buff is impregnated with a water-turbid liquid of an abrasive such as silica or zeolite, and the buff is used for polishing and removal.
When removing the mask using a stripping solution, it is necessary to perform a pore-sealing treatment to close the pores on the surface of the aluminum material in order to prevent the colored portion from being dissolved by the stripping solution. , The problem of not being able to print in multiple colors arises.

After the mask removing step, a sealing treatment is performed to close the pores on the surface of the aluminum material, if necessary. The pore-sealing treatment is performed by treating the aluminum material with steam, boiling water, nickel acetate, sodium silicate, etc., and the dye that has entered the pores on the surface of the aluminum material is trapped in the pores by this pore-sealing treatment. , Durable printed matter.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the example, "part" represents "parts by mass" and "%" represents "% by mass".

Table 1 shows the composition of the ultraviolet curable ink for masks used in the present invention.

The following evaluation tests were carried out on the ultraviolet curable ink for masks used in the present invention.

[Compatibility]
When the prepared ink was turbid or separated, it was evaluated as x, and when it was not turbid and separated, it was evaluated as ◯, and it was ◯.

[viscosity]
It was measured at 25 ° C. and 50 rpm using a cone plate type viscometer TV-22 (manufactured by Toki Sangyo), and was 5.4 mPa · sec.

[surface tension]
The surface tension at 25 ° C. was measured by the plate method using a surface tension meter CBVP-Z (manufactured by Kyowa Interface Science) and was 21.5 mN / m.

[Discharge stability]
Using an inkjet printer equipped with a piezo type inkjet head (KM512MH, manufactured by Konica Minolta) on an aluminum material produced by anodizing an aluminum plate whose surface has been degreased and polished by a conventional method, the resolution is 360 x 720 dpi, the printing ratio is 100%, and UV curing is performed. When solid printing of mold ink at 200 x 200 mm is performed, the case where non-ejection or non-image area stains do not occur by the end of printing is evaluated as ◯, and the case where non-ejection or non-image area stains occur is evaluated as ×. Met. The film thickness was 0.92 μm.

[Leveling property]
The mask layer was cured by irradiating ^{the test piece obtained in the discharge stability test with ultraviolet rays of 1000 mi / cm 2} using a high-pressure mercury lamp of 120 W / cm. When the surface of the obtained test piece was observed and many pinholes could be confirmed, it was evaluated as ×, a level △ with some pinholes but no problem in practical use, and a level ○ where pinholes could not be confirmed, and was evaluated as ○. ..

[Physical developability]
The test piece whose mask layer was hardened in the leveling test was rubbed for 1 minute with a cotton buff impregnated with a mixed slurry of water and a cleanser attached to an electric drill, and peeled off at a rotation speed of 250 rpm of the electric drill. If it was peeled off at 500 rpm, it was evaluated as ◯, if it was not peeled off, it was evaluated as ×, and it was ◯.

The compositions of the colorants of Example 1 and Comparative Examples 1 and 2 used in the present invention are shown in Table 2. In addition, the following evaluation tests were carried out, and the results are summarized in Table 3.

[Coloring process resistance]
The non-masked region of the test piece obtained by curing the mask layer in the leveling test is impregnated with a cloth with the coloring materials of Example 1 and Comparative Example 1 or 2, and the mask layer is invaded after coloring by rubbing. Those that were not stained and had no stains on the non-image areas were evaluated as ◯, and those that were invaded by the mask layer and had stains were evaluated as x.

[Staining concentration]
After the coloring process test, the mask is peeled off, and the coloring density is visually higher than that of Tokyo Ink COLOR GUIDE packaging gravure ink 7th edition, front printing 910 ink plate depth of 18 μm, and lower. Was evaluated as x.

Claims (7)

This is a method for manufacturing aluminum printed matter.
A mask forming step of masking a preset area on the surface of an aluminum material to form a mask pattern,
A coloring step of coloring a non-masked area other than the mask pattern with a coloring material, and
A mask removing step of removing the mask pattern and
Including
A oily dye the coloring material is dissolved in a water-containing organic solvent,
A method for producing a printed matter, wherein the mask thickness of the mask pattern is 0.5 μm or more and 7 μm or less. The method for producing an aluminum printed matter according to claim 1, wherein the mask pattern is formed by an inkjet method using an ultraviolet curable ink. Method of manufacturing an aluminum material printed matter according to claim 2, characterized in that it comprises at least one previous SL ultraviolet curable ink is selected from organic pigments and dyes. The method for producing an aluminum printed matter according to any one of claims 1 to 3, wherein the mask removal in the mask removing step is removal by polishing. It is a printing method of aluminum material.
A mask forming step of masking a preset area on the surface of an aluminum material to form a mask pattern,
A coloring step of coloring a non-masked area other than the mask pattern with a coloring material, and
A mask removing step of removing the mask pattern and
Including
A oily dye the coloring material is dissolved in a water-containing organic solvent,
A method for printing an aluminum material, wherein the mask thickness of the mask pattern is 0.5 μm or more and 7 μm or less. The method for printing an aluminum material according to claim 5, wherein the mask pattern is formed by an inkjet method using an ultraviolet curable ink. The method for printing an aluminum material according to claim 5 or 6, wherein the mask removal in the mask removing step is removal by polishing .