JPS5942992A - Material to be recorded - Google Patents

Abstract

PURPOSE:To provide a material to be recorded for ink jet recording excellent in sharpness of an recording image and color developability of ink, constituted so as to provide an ink absorbing layer to the material to be recorded while specific ink absorbing capacity is imparted to said material to be recorded. CONSTITUTION:An ink absorbing layer constituted from porous resin (e.g., PVA, PVC) or a filler particle (e.g., a silica particle) and a binder (e.g., PVA) is applied onto the surface of a support (e.g., paper) by a method, for example, a roll coating method pref. in an amount of about 2-30g/m<2> (on the basis of a dry coating amount) and dried to obtain an objective material to be recorded having ink absorbing capacity of 7.0X10<-3>mul/mm.<2> or more.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material (recording paper) used in an inkjet recording method, and particularly to a recording material that has excellent clarity of recorded images and excellent color development of ink.

Methods of recording using recording liquid have been common for a long time, such as writing with a fountain pen, but recently,
A so-called inkjet recording method has also appeared, and recording liquid is used here as well.

The inkjet recording method generates small droplets of recording liquid using various operating principles, and performs recording by flying these droplets and adhering them to a recording material such as paper. It is attracting attention as a recording method that allows printing and multicolor printing. Water-based recording liquids are mainly used for inkjet recording in terms of safety and printability.

As the recording material used in this inkjet recording method, conventional paper has generally been used. However, as the performance of inkjet recording machines improves, such as higher recording speeds and multicolor recording, more advanced properties are being required of recording materials for Infusiera I recording. In other words, in order to obtain high-resolution, high-quality recorded images, the recording material for inkjet recording must: 1) absorb ink as quickly as possible; 2) prevent ink dots from sticking later when they overlap.・The ink does not flow into the previous dot, 3) The diameter of the ink dot is the required amount 1--
4) The shape of the ink dot must be close to a perfect circle, and the surrounding area must be smooth. 5) The ink dot must have a high density and the area around the dot must not be blurred. It must meet the star-seeking performance of the shade. That is required.

In addition, the multi-color Z-exit recording type photocopy allows you to obtain a recorded image quality comparable to that of a color photograph.

In addition to the above required performance, 6) high whiteness, and 7) excellent coloring properties of the coloring components of the ink.

8) The same number of ink droplet forces as the number of ink colors 51ijl
- Since ink may be deposited in multiple places, it is required to have particularly good ink absorbency.

However, the reality is that a recording material that satisfies all of these required performances has not yet been found. For example, JP-A-52
The inkjet recording paper described in No. 74,304 is
The ink absorption is quick, the diameter of the ink tends to become large, and the periphery of the dot is blurred (easy to clean, and the dimensional change of the paper after recording is large). There is.

An object of the present invention is to provide a full-color recording material for inkjet/sheet recording that satisfies the above-mentioned requirements, and particularly has excellent clarity of recorded images and excellent color development.

The above and other objects are achieved by the invention as follows.

That is, the present invention provides a recording material in which an ink absorption layer is provided on the surface of a support, and the ink absorption capacity of the recording material is ? , OX 1O-3JLI /'mm' or more.

The ink absorption capacity defined in the present invention is a value determined based on the following measurement method. In other words, 10 nozzles with a nozzle diameter of 50ILL11 are installed at intervals of 8/IIIm.
Approximately 65cm in diameter from the inkjet recording machine installed
The ink droplets on the tiles are continuously ejected and attached to the recording material. At this time, the recording material is moved relative to the inkjet recording die, and the moving speed is changed to change the amount of ink adhesion per unit area. Next, blotting paper is pressed against the recording material to which the ink has adhered after 1 second, and the maximum amount of ink at which the ink does not transfer to the blotting paper is defined as the ink absorption capacity.

When the ink absorption capacity of paper with a conventionally available coating layer, such as art coated paper, is measured using the above measurement method, the ink absorption capacity is 5.5. When a color image is recorded using a color inkjet recording machine with a value of OX to -3h+ /mm2, the adhered ink may flow out, or the ink remaining on the paper may damage the recording device or the paper surface. It gets contaminated. On the other hand, plain paper without an ink absorption layer has an ink absorption capacity of 5.0
/mff12 in some cases, but the ink bleeds significantly, the print shape is poor, and furthermore, when a color image is recorded, the sharpness of the image is low.

In order to eliminate such drawbacks of conventional recording materials, the recording material should have an ink absorbing layer, and the recording material should have 7. OX 10' 41 / mm2 or more,
More preferably 1.0 x 10' 41/mm2
It has been found that it is sufficient to have the following ink absorption capacity.

Furthermore, it is more preferable that the ink absorbing layer alone has an ink absorbing capacity of L. Note that the ink absorption capacity of the ink absorption layer alone is different from that of glass, resin films, etc.
An approximate value can be obtained by providing an ink absorbing layer on a support having no ink absorbing property and measuring its ink absorbing capacity according to the method described above.

It is appropriate to use paper as the support for the recording material of Suekan J, but porous materials such as cloth, porous resin, wood, etc., and non-porous materials such as resin, metal, glass, etc. can also be used,
Which of these should be selected depends on the recording purpose and usage.

- Method 1 The ink absorbing layer of the recording material of the present invention is composed of a porous resin or filler particles and a binder.

When the ink absorbing layer of the recording material of the present invention is composed of a porous resin, any water-soluble or organic solvent-soluble resin that can be formed into a film can be used as the raw material resin. For example, water-soluble resins include polyvinyl alcohol, starch, casein, gum arabic, gelatin, polyacrylamide, carboxymethylcellulose, sodium polyacrylate, alginate sorta, etc., and organic solvent t+f-soluble resins include polyvinyl chloride, polyacetic acid, etc. Vinyl, polyacrylonitrile, polymethyl methacrylate-1, polyvinyl formal, melamine resin, polyamide resin, phenol resin.

There are polyurethane resins, alkyd resins, etc.

When using a water-soluble resin, problems such as deformation due to moisture absorption and excessive amount of ink bleeding may occur, so the porous resin layer may be further treated to make it waterproof. .

In the present invention, the method for creating a porous resin layer using the above resin is as follows: l) A substance that foams with heat or light is added to the resin, kneaded, molded (film formed), and then heated. Or a method of forming fine pores with air bubbles in the resin by irradiating it with light? ) After molding (film forming) a resin in which fine particles of a water-soluble inorganic salt (for example, sodium chloride) are dispersed, it is immersed in water, etc. 3) A method in which fine pores are formed in the resin by eluting salts into water. 3) After molding (film forming) fine particles such as zeolites, silica, and diatomaceous materials dispersed in the resin, acidic There is a method in which the fine particles are eluted by immersion in an aqueous solution to form fine pores in the resin matrix.

Incidentally, when employing method 2) or 3), any resin may be used as long as it is not dissolved in at least an aqueous solution or an acidic aqueous solution. For reference, examples of resins suitable for these methods include polyvinyl chloride, polystyrene, polyacrylonitrile, polyvinyl acetate, cellulose acetate, polyvinyl butyral, acrylic resin, polyamide resin, styrene-butadiene latex, alkyd resin. , polyvinyl alcohol, polyester resins, and their polymers.Furthermore, plasticizers for these resins can also be added, such as dibutyl phthalate, adipine dioctyl, polyethylene glycol, chlorinated paraffin, etc. be.

The porous resin layer formed in this way has a large number of pores in a random three-dimensional arrangement (2) in close contact with each other (in this case, a plurality of pores are connected to form a through hole). The size of these pores (pore diameter) is preferably such that capillary force acts on them, and is set in the range of several hundred angstroms to several microns. Further, the shape of the hole is not particularly limited.

In the present invention, the size and shape of these pores are determined after the resin body is formed into a film before being made porous.

By adjusting and controlling the additional conditions, it is possible to change them arbitrarily within the following ranges.

When the ink absorbing layer of the recording material of the present invention is composed of filler particles and a binder, the filler particles include, for example, silica, clay, talc, diatomaceous, 3-deficient acid, etc. Calcium, sulfate 11. White inorganic pigments such as barium sulfate, titanium oxide, zinc oxide, satin white, aluminum silicate, lithopone, alumina, zeolite; polystyrene, polyethylene, urea-formalin m
fat, polyvinyl chloride, polymethyl methacrylate, etc.

Examples include J4It polymer particles. It is preferable that the filler particles have higher dye adsorption properties, and inorganic pigments that contribute to the porous structure are particularly preferable. This is because the coloring matter in the ink absorbed into the gaps between the filler particles is trapped in the outermost layer of the ink absorbing layer, and the trichromaticity results in a good Ilf. The other binding material is starch.

Gelatin, casein, arabic L1. Water-soluble polymers such as alkinoic acid sorta, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, polysodium acrylate, and polyacrylamide; synthetic resin latex such as synthetic rubber latex, polyvinyl butyral, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, and There are 41 solvent-soluble resins such as methyl methacrylate, polyvinyl formal, melamine resin, polyamide resin, phenol resin, polyurethane resin, and alkyd resin, and one or more of these resins may be used. Further, various additives such as a dispersant, an IYT photodye, a PH adjuster, an antifoaming agent, a lubricant, a preservative, and a surfactant can be mixed in the ink absorption layer.

This type of recording material is prepared by dispersing these ink absorbing layer components in a medium such as water.
It is produced by coating on a support by a roll coach ink method, lot no-coating method, spray coating method, air knife coating method, etc., and then drying it as quickly as possible. Generally, the appropriate mixing ratio of filler particles and binder in the coating liquid is 10 to 1'00 parts by weight of binder to 100 parts by weight of filler particles, and the average particle size of filler particles is When the diameter is large, it is best to use as little binder as possible. Support -
The amount of the ink absorbing layer is usually about 1 to 50 g/m' (
Dry coating amount) is applied onto the substrate. Further, it is preferable to apply the coating at about 2 to 30 g/m' (dry coating amount).

In this way, the recording material of the present invention, which has an ink absorbing layer on the support and has an ink absorbing capacity value of a specific value or more, has a recording material of the present invention, in which recording liquids of different colors overlap in the same place within a short time. Even if the recording liquid adheres to the recording medium, there is no flow out or oozing phenomenon, and high-resolution, clear images can be obtained. Furthermore, 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 Silica (Syroid 404, trade name,
Manufactured by Fuji Deu'ison Chemical Co., Ltd., average particle size: 10u+
) and calcium carbonate, and polyvinyl alcohol and SBR latex as binders, an ink absorbing layer coating composition was prepared based on the following composition.

Silica +00 East! 4 parts Calcium carbonate 151/ Polyvinyl alcohol 3Q ttSBR Latinx 3 // Water
500 tt On the other hand, as a support, I used general paper (basis weight 85 g/m') with a size degree of 35 seconds based on JIS P8122.
Coated by blade coater method at a ratio of g/rn',
A recording material was obtained by drying in a conventional manner.

Color inkjet recording was performed on this recording material using the following four color inks, and the recording characteristics were evaluated.

Yellow ink (composition) C, 1, acid yellow 23 2 parts by weight diethylene glycol 3Q tt water
7Q tt magenta ink (composition), 1. Acid Red 82 2 parts by weight diethylene glycol 3Q tt water
7oll cyan ink (composition) C, 1, Direct Blue 88 2 parts by weight diethylene glycol 3Q tt water
70 l/black ink (
Composition) C, 1, Direct Black 182 Parts by weight Diethylene glycol 3Q tt Ice
Table 1 shows the evaluation results of the recording characteristics of the 7Q tt recording material.

Each evaluation item in Table 1 was determined by the method described below.

1) The ink absorption capacity is an on-demand inkjet recording head that ejects ink using a piezo vibrating element (discharge orifice diameter 50 mm, orifice installation width 24 mm).
3mm, piezo vibration element drive voltage 60V, frequency IK
Hz) according to the previous definition.

2) Dot density was measured using Sakura Microdensitometer P.
Measurement was performed using MD-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

3) To determine the dot shape, observe the printed dots with a stereomicroscope.
Irregular shapes were marked as ×.

4) The degree of bleeding is determined by measuring the diameter of the printed dot using a stereomicroscope.
l+ constant and expressed as how many times larger than the inkdron blend.

5) Color sharpness was determined by visual comparison of the color sharpness of the inkjet, 1-recorded images, and the best one was marked @, the worst one was marked ×, and the images were ranked as ○, ○, Δ, and ×.

Example 2 As a filler particle, diatom-(celite whey) mist, trade name, manufactured by Jeongmanpil, average particle size 5.5
A composition for coating an ink absorption layer was prepared based on the following composition using starch and SBR latex as a binder.

Diatomide 100 Parts by weight Starch 30 ttSBR latex lol/Water 800
tt On the other hand, the same high-quality paper as in Example 1 was used as the support, and the above coating composition was coated on this support with a dry coating amount of 15 g/m' using a blade coater method. It was coated 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 the table.

Example 3 Using clay (average particle size 1.1 scales) and barium sulfate (average particle size 0.3 ILm) as filler particles and casein as a binder, an ink was prepared based on the following composition. A composition for coating an absorbent layer was prepared.

Clay 80 parts by weight Barium sulfate 201/Casein 20 tt water
250//・ As a support, the same general J-paper as in Example 1 was used, and on this support, the coating composition described in - was applied in a dry coating amount of 2.
It was coated by a blade coater method at a rate of 0 g/rn' and dried by a conventional method to obtain a recording material.

This recording material was rated J+' in the same manner as in Example 1, and the results are shown in the table.

Example 4 10% by weight aqueous solution of polyvinyl alcohol 100wt
Part i and 30 parts of 13X type zeolite (molecular sieve taX manufactured by UC, C) powder were mixed and pulverized and mixed using a sand mill. The resulting mixture was applied to a 100 μs thick polyethylene terephthalate film to a 40 μs thickness using a coating rod bar and dried. This film was immersed for 2 minutes in a citric acid aqueous solution adjusted to pH 3, washed with water, and dried to obtain a porous film sheet.

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

Comparative Example 1 Inkjet recording characteristics were evaluated in the same manner as in Example 1 using a commercially available general printing paper, Ginkan (trade name, manufactured by Yamao Kokusaku Pulp Co., Ltd.) as a recording material. The results are shown in Table 1.

Comparative Example 2 Inkjet recording characteristics were evaluated in the same manner as in Example 1 using a commercially available general printing paper, SK Coat (trade name, manufactured by Yamao Kokusaku Pulp Co., Ltd.) as a recording material. The results are shown in Table 1.

Claims (1)

[Claims] (2) A recording material having an ink absorbing layer provided on the surface of a support, which has an ink absorption capacity? ,OX
A recording material for inkjet recording, characterized in that it has a particle diameter of 10' ILl/mm2 or more.