JPH06155896A - Forming method of light-transmitting image - Google Patents

Abstract

PURPOSE:To provide the forming method of a light-transmitting image using ink-jet recording, in which the defect of a conventional technique is solved, particularly a reverse-type image forming method having a high grade. CONSTITUTION:Color-developing properties are lost by the adhesion of ink in a colorant component contained in a recording medium in the forming method of a light-transmitting image, in which the droplets of ink are attached onto the recording medium having light transmitting properties to conduct recording.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a clear recorded image by using an ink jet recording method, and more particularly, to a translucent image which gives an image suitable for observing a projected image such as an overhead projector. It relates to a forming method.

[0002]

2. Description of the Related Art Ink jet recording methods have been attracting attention in recent years because they are inexpensive and easy to form color images. In the case of color ink jet recording, plain paper or dedicated coated paper is used as the recording medium. On the other hand, with the development of color recording technology, there is an increasing demand for colorization of images used for observing projected images such as overhead projectors. For example, an overhead projector image is often used mainly for presentations, but if a color image can be used at this time, it is more preferable because the content can be deeply impressed. Furthermore, the inkjet recording method can easily form a color translucent image at low cost, as compared with the conventional silver salt photography, electrophotographic method, or a method of attaching a color film.

Further, as a translucent recording medium for ink jet recording, conventionally, a transparent film such as a polyethylene terephthalate film provided with an ink receiving layer formed by coating a hydrophilic resin or ultrafine particles is proposed. Has been done. As such a recording medium, for example, Japanese Patent Laid-Open No.
The recording mediums described in JP-A No. 9-174381, JP-A No. 60-199689 and JP-A No. 2-276670 can be used.

[0004]

As one of presentation methods using an overhead projector, a method of expressing a design to be expressed in a color with high lightness in a background with low lightness (a method such as a so-called blue slide, Hereinafter referred to as white blank type). In particular, if you want to emphasize the design you want to express in one sheet of material, for example, rather than arranging color characters in a plain background, it is colorless (or of lightness in a solid background of a specific color). It is more effective to place blank characters of high color). However, in order to obtain a white blank type image using the inkjet recording method, it is necessary to solidly print the background color over the entire surface of the recording medium. Especially, in order to emphasize the contrast more, the background colors are set to Y, M, C and Bk.
It is preferable to use a mixture of two or more colors by combining inks.

However, in this case, there arises a problem that the consumption amount of ink increases more than necessary or the printing speed decreases. In addition to the above, there is a problem of curling after image formation caused by applying a large amount of ink to the entire surface, and beads such as beads called beading, which are formed by unfixed ink droplets gathering on the recording surface. There are problems such as unevenness, joint stripes that occur at the joints of each scanning line, non-uniformity of blue background such as light and shade unevenness due to variations in the ejection amount of the head in one scanning line, or crushing of blank areas. To do. Therefore, an object of the present invention is to provide a method for forming a translucent image using ink jet recording, in particular, a method for forming a high quality white blank type image, which solves the above-mentioned drawbacks of the prior art.

[0006]

The above problems can be achieved by the present invention described below. That is, the present invention provides a method of forming a light-transmitting image in which a droplet of ink is attached to a recording medium having a light-transmitting property to perform recording, in which the colorant component contained in the recording medium is attached to the ink. The method for forming a translucent image is characterized in that the coloring property is lost due to.

[0007]

As a result of intensive studies to solve the problems of the prior art, the present inventors have found that the method of the present invention having the above-mentioned structure does not cause the above-mentioned problems as compared with the conventional ink jet system. Further, the inventors have found that the ink consumption amount is small and a white transparent type transparent image can be efficiently provided, and thus the present invention has been accomplished. Further, the image obtained by the method of the present invention has the same excellent image quality as the white blank image formed by using a conventional silver salt photograph. Needless to say, according to the method of the present invention, it is possible to form the above-mentioned excellent light-transmitting image at a much lower cost and in a shorter time than the conventional method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to the preferred embodiments of the present invention. The feature of the method of the present invention is to use a translucent recording medium having a specific structure. The recording medium used in the method of the present invention comprises a substrate and an ink receiving layer, which itself is transparent. The term "translucency" as used in the present invention means that the linear transmittance is 2% or more, more preferably 10% or more. Further, when the ink receiving layer also serves as a base material, the base material may be omitted. As the substrate, a transparent film or plate made of plastic such as polyethylene, polyester and polypropylene, or glass can be used. As a material for forming the ink receiving layer, any known material can be used, but hydrophilic resins such as polyvinyl alcohol, polyvinylpyrrolidone and cellulose derivatives, colloidal silica and alumina sol, and a small amount of a binder for inorganic fine particles. Examples thereof include those to which a resin has been added.

The colorant contained in the recording medium may be any one as long as it does not impair the translucency of the entire recording medium and imparts a tint to the recording medium itself. It is possible to use organic compounds, pigments, chelate compounds, and compounds containing colored metal ions such as Cu ²⁺ and Ni ²⁺ , which have a color-forming molecular structure in the molecule, such as water-soluble dyes used in Is.

The ink used in the method of the present invention is a conventionally known ink containing water as a main component, an organic solvent such as a polyhydric alcohol, a dye as a colorant and, if necessary, other additives. . Further, if necessary, a substance that eliminates the color developability of the above colorant may be added separately. Any method may be used as a method of eliminating the color forming property, for example, a method of changing the electronic state of the colorant molecule by using an oxidation / reduction reaction or changing the pH, a method of decomposing the colorant molecule itself. , A method of changing the structure of the colorant molecule itself, and the like.

In the method of the present invention, Y, M, C and Bk are also included.
The four color inks may be used as they are in common with other normal recording, and a new recording head for ejecting a white blank type ink containing no dye is newly provided to form an image. Good. In the former case, an image in which characters and patterns of each color ink are recorded for the background color is obtained, and in the latter case, an image in which colorless (white) characters and patterns are recorded for the background color is obtained. Is obtained. As an inkjet recording method to which the method of the present invention can be applied, any of conventionally known inkjet recording methods can be used in which recording is performed by ejecting ink droplets from nozzles using various driving principles. Is also applicable.

[0012]

EXAMPLES The present invention will be described in more detail below with reference to examples. [ Examples 1 to 4 ] Translucent recorded images as shown in FIG. 1 were prepared by the image forming method of the present invention as shown below. As a recording apparatus, a recording apparatus equipped with an inkjet recording head having about 16 nozzles with a density of 1 mm is used to prepare the recording medium and ink shown below, and inkjet recording is performed on the portion corresponding to FIG. Thus, a white transparent type translucent recording image was formed.

Preparation of Recording Medium A 10% aqueous polyvinyl alcohol solution (PVA-
217 Kuraray) was mixed with 100 parts by weight of each colorant solution having the composition shown below to prepare a coating solution. The above coating solution was applied onto a polyethylene terephthalate film having a thickness of 75 μm so that the dry film thickness was 5 μm, and dried to form an ink receiving layer.
The recording media used in No. 4 were prepared respectively.

Colorant solution composition ( colorant solution used in Example 1) 0.04 mol / l potassium permanganate aqueous solution and 0.2 mol / l sulfuric acid aqueous solution were mixed in a weight ratio of 1: 1. It was a colorant solution. (Colorant solution used in Example 2) Aqueous ammonia solution was added to 0.02 mol / l cupric chloride aqueous solution to precipitate cupric hydroxide, and then excess ammonia aqueous solution was further added to 0.02 mol. A solution containing a corresponding copper ammine complex ion of 1 / l was prepared as a colorant solution.

(Colorant solution used in Example 3) 0.06
mol / l sodium acetate aqueous solution and 0.02 mol
/ L ferric chloride aqueous solution was mixed at a weight ratio of 1: 1 to obtain a colorant solution. (Colorant Solution Used in Example 4) A 0.06 mol / l sodium salicylate aqueous solution and a 0.02 mol / l ferric chloride aqueous solution were mixed at a weight ratio of 1: 1 to prepare a colorant solution.

Preparation of Ink (Ink Used in Example 1) An aqueous 0.1 mol / l sodium oxalate solution was prepared as an ink. (Ink used in Example 2) A 0.04 mol / l potassium cyanide aqueous solution was prepared and used as an ink.

(Ink used in Examples 3 and 4)
An ink was prepared based on the following composition. -Diethylene glycol 30 parts-Water 67 parts-Dye 3 parts An aqueous hydrochloric acid solution was added to the above mixed solution to adjust the pH to 3 to prepare an ink. This ink can be normally used for conventionally known recording media such as recording paper. A yellow image (using CI Direct Yellow 86 as a dye) among the above inks was used to form a light-transmitting image.

As a result, translucent images of white were obtained on the reddish purple background in Example 1 and the blue background in Example 2, respectively. In addition, a translucent image of yellow characters was obtained on the red background in Example 3 and the reddish purple background in Example 4, respectively.

[Comparative Example 1] Using the following recording medium,
Inkjet recording similar to that of the conventional example was performed by the same recording method as that of the example so that the part was blue (printed with cyan ink and magenta ink) and the part was plain (no printing).
A translucent recorded image was formed.

Preparation of Recording Medium On a polyethylene terephthalate film having a thickness of 75 μm, a 10% polyvinyl alcohol aqueous solution (PVA-2 was used.
17 Kuraray Co., Ltd.) was applied and dried so that the dry film thickness was 5 μm to form an ink receiving layer, and a recording medium was prepared.

[0021]

[Evaluation] Comparison of ink consumption during recording shows Comparative Example 1
Was 10 times or more the amount of ink consumed as in the example of the present invention. In addition, using the translucent images of the formed Examples and Comparative Examples, a projection image was formed and evaluated using an overhead projector. The images of the examples of the present invention each formed a sharp and projected image with contrast, whereas the image of Comparative Example 1 generated curl on the recording surface side.
No clear projected image was formed.

[0022]

As described above, according to the method of forming a light-transmitting image of the present invention, unlike the conventional ink jet recording system, the ink consumption amount is small and the white transparent type transparent image is efficiently used. An optical image is obtained. Further, the white transparent type light-transmitting image obtained by the method of the present invention has the same high quality as a white transparent image formed by using a conventional silver salt photograph. Further, according to the method of the present invention, it is possible to form the above-mentioned excellent light-transmissive image at a much lower cost and in a shorter time than the conventional method.

[Brief description of drawings]

FIG. 1 is a view exemplifying a translucent image formed by a method of the present invention.

Claims (1)

[Claims] 1. A method for forming a light-transmitting image in which a droplet of ink is adhered to a recording medium having a light-transmitting property to perform recording, wherein the colorant component contained in the recording medium is A method for forming a translucent image, characterized in that it loses color developability.