JPS5945188A - Material to be recorded - Google Patents

Abstract

PURPOSE:To obtain a high performance material to be recorded (recording paper) which can meet almost all requirements in the recording employing a liquid ink of inkjet recording type by arranging a cover layer to contain crystalline cellulose. CONSTITUTION:A material to be recorded is composed of a support and a cover layer provided on the surface thereof. The support can use paper and other porous and non-porous material while the cover layer is made up of a film-forming resin coat containing crystalline cellulose. The product thus obtained is so high in the ink absorptivity as the eliminate spillage or exudation of recording liquids even when recording liquids different in color attached to the same position overlapping briefly thereby proving a clear image with a high resolution. This also displays an excellent property in the color formability making it ideal for inkjet recording in full color.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material (hereinafter abbreviated as recording paper) used for recording characters, figures, etc. using a recording liquid.

Conventionally, recording with a recording liquid, that is, ink, has been widely performed using, for example, a writing implement such as a pen, a fountain pen, or a felt pen. Also, in recent years, a so-called inkjet recording method has appeared, and recording liquid is used here as well.

Incidentally, this inkjet recording method uses various ink ejection methods (for example, an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, a method that uses a piezoelectric element to apply mechanical vibration or displacement to the ink, and a method that heats and foams the ink and uses the pressure (1) A method in which all ink droplets (aropzθt) are formed and some or all of them are attached to a recording material such as paper for recording. It is.

In this way, when recording using liquid ink, it is generally necessary that the ink does not bleed onto the recording surface and cause the print to become blurry, and that the ink is used as quickly as possible after recording. To avoid accidentally contaminating the paper surface by drying, and
The pigments in the ink fixed on the paper tend to discolor or fade.

In particular, in the inkjet recording method, (1) the absorption of the recording liquid (ink) into the recording paper is fast; (2) especially when performing multicolor or full color recording;
Even if ink dots overlap, the ink that has adhered later should not disturb or flow out the dots that have adhered earlier. (2) Do not sharpen the dot more than necessary; (4) The shape of the ink dot should be close to a perfect circle, and the surrounding area should be smooth; (5) The density of the ink dot should be high, and the area around the dot should be blurred. (6) The color of the recording paper is white and has a large contrast with the ink dots. (7) The color of the ink does not change depending on the type of recording paper. (8) There is little scattering of ink drops around the ink dots. (9) It is necessary to satisfy various requirements such as: (9) There should be little dimensional variation (for example, wrinkles, stretching) of the recording paper before and after recording. However, in order to satisfy these demands, conventionally,
It is well understood that the quality of paper depends on the characteristics of the recording paper used, but in reality, there is still no recording paper that can meet the various requirements on boards, whether it is plain paper or processed paper. It is in. For example, the processed paper for inkjet recording (3) described in JP-A-52-74340 absorbs ink quickly, but as soon as the diameter of the ink dots becomes large, the periphery of the dots tends to blur. ,or,
This method has the disadvantage that the size of the paper changes significantly after recording. SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to satisfy the problems that the prior art could not solve in the field of board technology.

Particularly, the present invention aims to provide a high-performance recording material (recording paper) that satisfies almost all of the requirements on a writing instrument or a board in recording using liquid ink using an inkjet recording method. There is.

The recording material of the present invention that achieves the above object is characterized by comprising a support and a coating layer provided on the surface of the support, and the coating layer contains crystalline cellulose. In the present invention, the deposited recording liquid (ink) is quickly absorbed into the interior of the ink, and even if recording liquid of a different color is repeatedly deposited on the same spot within a short period of time, no leakage or smearing of the recording liquid occurs. There is no bleeding phenomenon, and the spread of printed dots is reduced.
It is possible to provide a recording material particularly suitable for inkjet recording, which can suppress the image quality to a level (4) that does not impair the sharpness of the image.

The crystalline cellulose used in the present invention is obtained by hydrolyzing ordinary cellulose, leaving only crystalline regions in which molecules are arranged in parallel in a relatively regular manner, which is ground, purified, and dried, and is chemically inert. and generally insoluble.

Generally, natural cellulose powder is light and requires a large amount of water to make a suspension, making it difficult to disperse it uniformly, but crystalline cellulose does not have such concerns and is easy to handle.

Crystalline cellulose is generally insoluble but highly hydrophilic, and its powder is an aggregate of many fine crystalline cellulose particles with many voids between the particles, so it has very good ink absorption properties. A recording material can be obtained.

In addition, crystalline cellulose adsorbs dye very easily and uniformly, leaving the dye near the surface of the recording material.Furthermore, the coating layer containing crystalline cellulose is highly transparent, resulting in very clear recorded images (5. ) is obtained.

The recording material of the present invention comprises a support and a coating layer provided on the surface of the support.

As a support for the recording material, it is appropriate to use paper, but porous closing materials such as side cloth, porous resin, and wood, and non-porous materials such as resin, metal, and glass may also be used. However, which one to select depends on the recording purpose and use.

On the other hand, the coating layer of the present invention is basically composed of a film-forming resin coating containing the crystalline cellulose, but crystalline cellulose and other filler particles can also be used together.

Examples of filler particles include silica, clay, talc,
White inorganic pigments such as diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, titanium oxide, lead oxide, satin white, aluminum silicate, lithopone, alumina, zeolite; polystyrene, polyethylene, urea.
75 organic polymer particles such as formalin resin, polyvinyl chloride, polymethyl methacrylate, etc. were listed.

(6) It is preferable that filler particles have higher dye adsorption properties, and inorganic pigments having a porous structure are particularly preferable.

This is because the color development is better when the pigment in the ink absorbed into the gaps between the filler particles is captured in the deepest region of the coating layer.

Incidentally, even when crystalline cellulose and the filler particles are used together, it is preferable that the crystalline cellulose is contained in the coating layer in an amount of 60% or more by weight.

On the other hand, the binder includes water-soluble polymers such as starch, gelatin, casein, gum arabic, sodium alginate, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, and polyacrylamide; synthesis of synthetic rubber latex, etc. Examples include organic solvent-soluble resins such as resin latex, polyvinyl butyral, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polymethyl methacrylate, polyvinyl formal, melamine resin, polyamide resin, phenol resin, polyurethane resin, and alkyd resin.
and (7) one or more types of targets are used. Various additives such as a dispersant, a fluorescent dye, a pH adjuster, an antifoaming agent, a lubricant, a preservative, and a surfactant can also be mixed in the coating layer.

This type of recording material is produced by dispersing these components in a medium such as water and applying a coating solution onto a support using a roll coating method, rod bar coating method, spray coating method, air knife coating method, etc. It is produced by coating and then drying as soon as possible. The appropriate mixing ratio of crystalline cellulose and binder in the coating solution is generally 10 to 100 parts by weight of binder per 100 parts by weight of crystalline cellulose.

Then, this coating liquid is usually applied to about 1 to 50 g/m2 (
(dry coating weight) on the support. It is preferable to apply the coating at a rate of about 2 to 30 g/m2 (dry coating).

In this way, the supplementary diagonal material of the present invention, in which a coating layer containing crystalline cellulose is provided on the support, has extremely high ink absorption, and recording liquids of different colors overlap in the same place within a short (8) time. Even when the recording liquid adheres to the recording liquid, there is no flow-out or oozing phenomenon of the recording liquid, and a clear image with high resolution is provided. Moreover, it exhibits excellent color development properties and is suitable as a recording material for inkjet recording when performing full-color recording.

Hereinafter, the present invention will be explained in more detail according to Examples.

Example 1 Avicel SF (trade name, "crystalline cellulose" manufactured by Mukasei Kogyo ++i) 100 parts by weight, polyvinyl alcohol 3
A coating composition was prepared by dispersing and dissolving 0 parts by weight and 3 parts by weight of SDR latex in 1000 parts by weight of water.

On the other hand, as a support, general high-quality paper (basis weight 65 g/m2) with a size degree of 35 seconds based on J Engineering 5P8122 was used.
The above coating composition was applied on this support in a dry coating amount of 20.9
The recording material was coated with a blade coater method at a ratio of '/m2 and dried by a conventional method to obtain a recording material. Color inkjet recording was performed on this recording material using ink (9) of the following four colors, and the recording characteristics were evaluated.

Yellow ink (composition) 0, T, acid yellow 23 2 parts by weight diethylene glycol 30 #water
70 F magenta ink (composition) C, T, acid red 92 2nd part diethylene glycol 50! water
70 l cyan ink (composition) 0, ■, Direct Blue 86 2 parts by weight diethylene glycol 3 o l water
70 ・Black ink (
Composition) CO, Direct Black 19 2 parts by weight diethylene glycol 3o l water
Table 1 shows the evaluation results of the recording properties of the #70 recording material.

In addition, each evaluation item in Table 1 is as follows (10
) method.

(1) Ink absorption is determined by overprinting three colors of ink, cyan, magenta, and yellow, and rubbing it with your finger after 1 second.
Those with no ink on their fingers were evaluated as ○, and those with ink on their fingers were evaluated as ×.

(2) The dot density was measured using a Sakura microdensitometer PMD-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

(3) Regarding the dot shape, the printed dots were observed with a stereoscopic microscope, and a round dot was determined to be ◎, and a circular dot with some crumbs was determined to be ○.

(4) The degree of bleeding was determined by determining the diameter of a printed dot using a stereomicroscope as 1t (I+), and expressed by how many times larger the diameter of the printed dot was than that of an ink droplet.

(5) Color clarity is determined by visually comparing the color clarity of inkjet recorded images and selecting the best one as ◎ or ◎.
Those with a good rank that was slightly inferior to the rank of were judged as ○.

Example Z 50 parts by weight of Avicel SF (trade name, "Kui (11) crystalline cellulose" manufactured by Mukasei Kogyo ■), 50 parts by weight of Nibseal E150 (trade name, "ultrafine hydrated silicic acid" manufactured by Nippon Silikani Industry tVl→) , 30 parts starch, 10 parts by weight of S]3R latex, and 800 parts by weight of water were stirred and mixed to prepare a coating composition.

On the other hand, the same general high-quality paper as in Example 1 was used as a support, and the above coating composition was dried and coated on this support.
It was coated using a bar coater method at a ratio of g/m 2 and dried by a conventional method to obtain a recording material.

This recording material was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 A coating composition was prepared by stirring and mixing 100 parts by weight of Avicel EIF (trade name, 6-crystalline cellulose manufactured by Asahi Kasei Corporation), 50 parts by weight of methylcellulose, and 1000 parts by weight of water.Meanwhile, A polyethylene terephthalate film with a thickness of 75 μm is used as a support, and the above coating composition is coated onto this support at a dry coating amount of 8 g/m2. I got the material.

This Hayashi recording material was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Furthermore, inkjet recording was performed on this recording material using only the black ink shown in Example 1, and the resulting document was used as a document to be copied using a dry type diazo copying machine to obtain a good quality copied image.

Table-1 Patent applicant: Canon Co., Ltd. (13)

Claims (1)

[Claims] A recording material comprising a support and a coating layer provided on the surface thereof, wherein the coating layer contains crystalline cellulose.