JP2004174971A - Method for forming white ink ground and method for printing by inkjet system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide easily and in a low cost a method for forming a white ink ground and a method for printing by an inkjet system. <P>SOLUTION: The method comprises the following processes. In a ground preparing process, the whole face or a part of a dark-colored body 1 to be printed is coated with a UV-curable white ink 3 and is dried. In a primary printing process, a black plain color printing is performed on the body 1 to be printed so that base data on characters, extraction positions and the like printed on the body 1 to be printed are made to be white 100% at a part 4 where a white ink is required, and black 100% at the other part 5, and a part 5 where no white ink is required is masked with the black ink. In a white ink ground forming process, after the white ink 3 on the part 4 where the white ink is required is cured by irradiating the body 1 to be printed with UV, the black ink masked on the part 5 where the white ink is not required and the white ink 3 are washed out by alkali washing. In a secondary printing process, an inkjet printing is performed on a white ink ground 4' of the preceding process based on the base data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink-jet printing method using a UV-curable white ink, and more particularly to a method for forming a white ink base and printing method by an ink-jet method suitable for a dark-colored printing medium.
[0002]
[Prior art]
2. Description of the Related Art In recent years, inkjet printing technology has been widely used in various fields, not limited to paper and films. However, the biggest drawback of this ink jet printing is that the transparency of the ink itself is influenced by the color of the base. For this reason, even for a dark base such as black or dark blue (plastic, metal, leather, cloth, wood, stone, etc.), the color development is affected by the color of the base even if the base is directly printed by the inkjet method. In particular, in the case of a black base, only traces of the print remain, so it makes no sense at all, and printing is difficult in practice.
[0003]
In order to solve such problems, white ink for ink-jet printing has been developed and practically used in a very small part, but the printing apparatus itself that can use this white ink is very expensive, For example, it is necessary to adjust the composition of the ink depending on the type of the ink, and the ink cannot be widely used.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above situation, and is not limited to the concept of inkjet printing the white ink itself, and the formation of a white base on a dark base is achieved by applying white ink and inkjet printing technology. It is an object of the present invention to provide a white ink base formation and printing method by an ink jet method which can be easily and inexpensively performed by using them together.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a method of the present invention is to provide a white ink base preparation step of applying a UV curable white ink to the entire surface or a part of a dark print substrate and drying the same, and printing the print substrate on a personal computer. The basic data (color data) obtained by digitally processing necessary information such as characters, figures, drawing positions, etc., is converted into monochrome data. The portion requiring white ink is 100% white, and the other portions (portions not requiring white ink) ) Is a data conversion step of converting to black 100%, and based on the converted monochrome data, ink-jet printing is performed on the printing medium with a single black color. Unnecessary portions are masked with black ink in a primary printing step, and portions of the printing medium that require UV irradiation by UV irradiation are After the white ink is cured, the white ink masked by the alkali washing is used to wash out the unneeded portions of the black ink and the uncured white ink, the white ink base forming step, and the white ink formed by the step A second printing step of drawing an image by performing ink-jet printing on the base based on the base data (color data).
[0006]
Specifically, in the data conversion step, the data conversion step converts the digitally processed base data (color data) into monochrome data, converts the monochrome data into two gradations, and requires white ink. The portion is converted to 100% black, and the other portions (portions not requiring white ink) are converted to 100% white, and then the two-tone conversion data is inverted to convert the portion requiring the white ink to 100% white. The other parts are converted to 100% black.
[0007]
The UV curable white ink includes a light color close to white, for example, a light cream color.
[0008]
The black color of the monochrome data includes a dark color close to black, for example, a dark blue color and a dark color that cuts a wavelength range of UV curing.
[0009]
Further, when the printing medium has a water absorbing property, after applying a white ink penetration preventing coating agent in advance so that the UV-curable white ink does not soak into the printing medium, and performing a water-repellent treatment, The UV curable white base material is applied.
[0010]
If necessary, after the second printing step, the surface of the printing medium is subjected to a top coat such as coating a surface treatment agent (for example, urethane resin) to complete the product.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a printing medium 1, and the printing surface is a dark color 2 such as black or dark blue. FIG. 2 shows a white ink base preparation step according to the present invention, in which a UV curable white ink 3, for example, RD-420W manufactured by Ryo Kagaku Kogyo Co., Ltd., is applied to the printing surface of the substrate 1 and dried. . In the illustrated example, the white ink 3 is applied to the entire printing surface of the printing medium 1, but may be partially applied as needed. When the printing medium 1 is made of an absorbent material, a coating agent for preventing white ink from penetrating is applied first and then subjected to a water-repellent treatment.
[0012]
On the other hand, basic information (color data) is generated by digitally processing necessary information such as characters, figures, and drawing positions to be printed on the printing medium 1 by a personal computer. Then, the base data (color data) is converted to monochrome in order to expose a portion of the print medium 1 requiring white color. Next, the monochrome data is converted into two gradations, and as shown in FIG. 3, the target image to be printed and the character portion (portion requiring white ink) 4 become 100% black and the other portions ( The portion 5 where white ink is unnecessary) is converted to 100% white. Subsequently, the two-gradation conversion data is inverted, and as shown in FIG. 4, the portion 4 requiring the white ink is set to 100% white, and the other portion (the portion not requiring the white ink) 5 is set to 100% black. . When ink-jet printing (primary printing) is performed on the printing medium 1 with a single black color based on the conversion data of two gradations, a portion 4 requiring white ink is not printed, and other portions (white ink is unnecessary). Portion 5 is printed black and masked. The printed object 1 printed in this manner is irradiated with UV light by a black light or the like, and a portion 4 requiring white ink, which is not masked by the black ink and exposes the white ink 3, is UV-cured. After the white ink 3 in the portion 4 is cured, the print substrate 1 is washed with an alkaline solution, for example, a soap solution, and the uncured white ink applied to the portion 5 where the white ink is unnecessary together with the black ink for masking. When the white ink 3 is washed away, the dark color 2 of the base is exposed at the portion 5 where the white ink is unnecessary, and the target image and the white ink base 4 'of the character to be printed with the cured white ink 3 are formed as shown in FIG. You. A normal undercoating agent 6, for example, a mixed solution of RD1120 and RD1125 manufactured by Ryogo Kagaku Kogyo Co., Ltd. is applied to the substrate 1 on which the white ink base 4 'is formed as described above, dried, and digitally processed. Inkjet printing (secondary printing) is performed on the white ink base 4 ′ based on the base data (color data), and the target image, characters, etc. are printed in color 7 to complete the printing operation. It should be noted that the undercoat treatment may not be necessary when ink other than the water-based ink is used. Further, if necessary, the surface of the printed substrate 1 is coated with a urethane resin, lacquer or the like to obtain a finished product.
[0013]
As described above, the white ink base 4 ′ of the printing medium 1 is formed by converting the digitally processed base data (color data) into monochrome data and performing inkjet printing (primary printing) based on the monochrome data. Therefore, when a printing operation (secondary printing) is performed on the white ink base 4 'based on the base data (color data) by the ordinary ink jet method, a printer capable of accurately grasping the print start position (origin) is prepared. If so, it is possible to print accurately without causing a displacement.
[0014]
【The invention's effect】
As described above, according to the present invention, a white ink base of any image or character based on the base data digitally processed on a dark print medium such as black or dark blue is printed by the inkjet method (first print). In addition to being able to form easily and inexpensively, it is possible to draw an accurate image without misalignment on the formed white ink base by inkjet printing (secondary printing) based on the base data.
[0015]
Therefore, the method of the present invention is expected to dramatically expand the application range of inkjet printing.
[Brief description of the drawings]
FIGS. 1A and 1B are explanatory views of a printing medium to which the method of the present invention is applied, wherein FIG. 1A is a plan view and FIG.
FIGS. 2A and 2B are explanatory views of a white ink base preparation step according to the method of the present invention, wherein FIG. 2A is a plan view and FIG.
FIGS. 3A and 3B are explanatory views of a conversion process of converting the basic data into monochrome by the method of the present invention, wherein FIG. 3A is a plan view and FIG.
FIGS. 4A and 4B are explanatory views of a reversal step and a first printing step of conversion data converted into monochrome by the method of the present invention, wherein FIG. 4A is a plan view and FIG.
5A and 5B are explanatory views of a white ink base forming step and a secondary printing step according to the method of the present invention, wherein FIG. 5A is a plan view and FIG.
[Explanation of symbols]
Reference Signs List 1 Printed object 2 Dark color 3 UV curable white ink 4 Part requiring white ink 4 'White ink base (after UV curing)
5 Area where white ink is not required (black ink masking area)
6 Undercoat agent 7 Color printing (secondary printing)

Claims (4)

A white ink base preparation step of applying a UV curable white ink to the entire surface or a part of the dark print medium and drying the same.
The base data (color data) obtained by digitally processing necessary information such as characters, figures, drawing positions, and the like to be printed on the print medium in a personal computer is converted into monochrome data, and a portion requiring white ink is converted to 100% white, and other parts are converted to monochrome. A data conversion step of converting a portion (a portion not requiring white ink) to 100% black;
Based on the converted monochrome data, primary printing is performed by performing ink-jet printing with a single black color on the print medium, printing no portion where the white ink is required, and masking black ink for the portion not requiring the white ink. Process and
After irradiating the printing medium with UV light to cure the white ink in the portion where the white ink is necessary, the black ink and the uncured white ink in the unnecessary portion where the white ink masked by alkali washing is unnecessary. A step of forming a white ink base to be washed away,
Forming a white ink base by an ink-jet method and a printing method including performing a second print step of performing an ink-jet print on the white ink base formed in the above step based on the base data (color data) to draw an image. The data conversion step converts the digitally processed base data (color data) into monochrome data, converts the monochrome data into two gradations, a portion requiring white ink becomes 100% black, and the other portions ( The portion that does not need white ink) is converted to 100% white, and then the two-tone conversion data is inverted to convert the portion requiring the white ink to 100% white and the other portions to 100% black. 2. The method for forming a white ink base and printing by an ink-jet method according to claim 1. When the printing medium has water absorption, the UV-curable white ink is applied after a coating agent for preventing penetration is applied in advance so that the UV-curable white ink does not soak into the printing medium. 3. A method for forming a white ink base and printing by an inkjet method according to 1 or 2. 4. The method of forming a white ink base and printing according to claim 1, wherein the UV-curable white ink is added with a chemical that develops a different color by UV irradiation.

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