JPS5935978A - Material to be recorded - Google Patents

Abstract

PURPOSE:To obtain a material to be recorded with ink absorptivity and an excellent color forming property by providing a covered layer on the surface of a support so that irregular forms of particles of a porous inorganic pigment appear on the surface thereof. CONSTITUTION:100pts.wt. of porous inorganic pigment particles (e.g. diatomaceous earth) with the size of 1-30mum are blended with 10-100pts.wt. of a binder (e.g. PVA) and a dispersant, a fluorescent dye, a pH adjusting agent, a defoaming agent, a lubricant, a preservative, a surfactant and the like as required and dispersed into a medium such as water to obtain a coat liquid. Then, the coat liquid is applied on a support such as paper in the range of 1- 50g/m<2> and dried as quickly as possible to form a covered layer on the surface of which irregular forms of particles of the pigment appear. This eliminates possible oozing out and exudation of recording liquid of different color even when being overlapped at the same position within a short period thereby ensuring a clear picture with a high resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material (recording paper) used in an inkjet recording method. Regarding materials.

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 ink sheet recording system has also appeared, and recording liquid is also used here.

The inkjet recording method generates small droplets of recording liquid using various operating principles, and performs recording by flying these droplets and landing them on a recording material such as paper, but it produces less noise. It is attracting attention as a recording method that allows high-speed 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. but,
As the performance of inkjet recording machines improves, such as faster recording and multicolor recording, recording materials for inkjet recording are also required to have more advanced characteristics. 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) absorb the ink as quickly as possible; The ink should not flow into the 17X dot, 3) The diameter of the ink dot should not be larger 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 ink driver 1. It is required that the image quality is high, and that it satisfies the required performance such as 1) that the periphery is not blurred, and that the periphery is not blurred.

Furthermore, in order to obtain a recorded image quality comparable to that of a color photograph using the multicolor ink side recording method, in addition to the required performance listed in "-", 6) a high level of whiteness 1■, and 7) a high level of coloring components in the ink. 8) The ink absorbency is particularly poor because the same number of small ink droplets as the number of ink colors may be deposited in the same place. ′! The performance of 9 is weighted and required.

However, the reality is that there is no recording material that satisfies all of these required performances. For example, the ink side recording paper described in Nos. 4 to 52-74, 304 has quick absorption of ick, but the dot I-diameter tends to become large and the periphery of the dot tends to be blurred. It also has the disadvantage of large dimensional changes after recording.

An object of the present invention is to provide a full-color recording material for ink-end recording that satisfies the above-mentioned requirements and has particularly high ink absorption 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 a coating layer containing a porous inorganic pigment and a binder is provided on the surface of a support, in which the irregular particle shape of the porous inorganic pigment is formed on the surface of the coating layer. This is a recording material for Infusiera i recording, which is characterized by appearing in the following.

The recording material of the present invention is characterized by the unique surface state of the coating layer that functions as a recording liquid receiving layer.

That is, the amorphous porous inorganic pigments with relatively large particle diameters, which are the main components of the coating layer, appear on the surface of the coating layer in a randomly placed state, and there are gaps between the porous inorganic pigment particles. It has a structure in which a large number of large voids that function as ink absorption holes are scattered, and typically, as in the state shown in FIG. 1, iJ<. Of course, the porous inorganic pigment particles appearing on the surface are also fixed within the coating layer by the binder and do not easily separate from the coating layer. FIG. 1 shows approximately 111 scanning type 'marks' V on the surface of the coating layer of the recording material of the present invention.
The surface condition is clearly shown, and could be described as having debris of various sizes scattered about.

FIG. 2 is an electron micrograph at the same magnification of the surface of a recording material having a conventional coating layer. These surfaces have a surface structure in which the coating layer is flattened while having many fine pores that serve as absorption holes for the recording liquid, and are clearly distinguished from the recording material of the present invention.

As described above, on the surface of the coating layer of the recording material of the present invention, there are large and numerous voids between the porous inorganic pigment particles, which serve as ink absorption pores. It is quickly absorbed into the gaps between inks and has a large ink absorption capacity.

As the support for the recording material of the present invention, it is appropriate to use paper, but cloth, resin film, synthetic paper, etc. can also be used.

On the other hand, the coating layer of the recording material of the present invention is basically composed of a porous inorganic pigment and a binder. Examples of the porous inorganic pigment include silica, clay, carbon dioxide, calcium carbonate, calcium sulfate, satin white, aluminum silicate, alumina, and zeolite, and one or more of these may be used. In order for the irregular shape of the porous inorganic pigment particles to appear on the surface of the coating layer, as if scattered rubble, the particle size of the porous inorganic pigment used must be 1 to 3.
It is desirable that the size is 0 scales, more preferably about 3 to 201 units. If the particle size of the porous pigment is too large, the roundness of the ink dots will be impaired and the resolution of the recorded image will be reduced, which is not preferable. Furthermore, if the inorganic pigment is not porous, it is not suitable because the density and roundness of the ink dots will decrease due to the pigment's low dye adsorption ability. If the pigment is porous, the pigment in the ink absorbed into the gaps between the pigment particles will penetrate into the porous inorganic pigment particles on the outermost layer of the recording material, causing the color to ↑
No. 1 or good.

Binding A (1 includes water-soluble polymers such as starch, gelatin, casein, gum arahia, sorta alginate, carboxydimethylcellulose, polyvinyl alcohol, polyhinylpyrrolidone, polyacrylic soda, polyacrylamide, etc.) ; Synthetic resin latex such as synthetic rubber latex, polyvinyl butyral, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polymethyl methacrylate-1, polyvinyl formal, melamine 4Nl!, polyamide, phenol 4bl I+
Examples include organic solvent-soluble resins such as polyurethane and alkyd resins. In addition, the coating layer may include other pigments such as plastic pigments, dispersants, fluorescent dyes, pH adjusters, antifoaming agents, etc., within the range that does not impair the effects of the present invention.
71 yen 1 Various additives such as lubricants, preservatives, surfactants, etc. can also be mixed.

In the recording method of the present invention, a coating solution prepared by diluting these coating layer components in a medium such as water is coated by a roll coating method, a rod bar coating method, a spray coating method, an air knife coating method, etc. It can be manufactured by coating the product on the body and then drying it as soon as possible. Generally, the appropriate mixing ratio of the porous inorganic pigment and the binder in the coating T liquid is 10 to 100 parts by weight of the binder per 100 parts by weight of the porous inorganic pigment; When the average particle size of the binder is large, it is beneficial to use as few binder gates as possible. The amount of the second coating layer on the support is usually about 1 to 50 g/rn' (
Dry coating amount) is applied to the substrate. Further, it is preferable to apply the coating in an amount of about 2 to 30 g/rn'' (dry coating amount).

The recording material of the present invention, in which a coating layer with a unique surface condition is provided on a support in this way, has extremely high ink absorbency, and when recording liquids of different colors overlap in the same place within a short time. However, there is no phenomenon of recording liquid flowing out or seeping out, and clear images with high resolution 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 (Zyroid 404, trade name, manufactured by Fuji Davison Chemical Co., Ltd., average particle size: 1) was used as a porous inorganic pigment.
0μff+), and polyvinyl alcohol and SBR latex as binders, based on the following composition]
A composition for - was prepared.

Silica 100 parts by weight Polyvinyl alcohol 25 ttSBR Latte Nx
51/Wed
500 tt On the other hand, as a support, J
General 1- with a size degree of 35 seconds based on ISP P8122
This support is made of quality paper (jfffi85g/rn')! Dry coating amount of the coating composition described in -2- 15g/m''
A recording material was obtained by coating with a blade coater method and drying by a conventional method.

FIG. 1 shows a scanning electron micrograph of the surface of the coating layer of the obtained recording material, magnified approximately 1500 times.

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) c, r, acid red 82 2 parts by weight diethylene glycol 301/water 701!
Cyan ink (composition) C, 1, Direct Blue 86 2 Parts by weight Diethylene glycol 301/Water 70
l/black ink (composition) C, 1, direct blank 19 2 parts by weight diethylene glycol 301/water 7Q
//O Table 1 shows the evaluation results of the recording characteristics of the recording material.

1) 1., 1.1m IN is a ton of printing! 4111 was determined using a Sakura Microtensitometer PI) M-5 (manufactured by Konishi Rokusha Co., Ltd.).

2) To determine the shape of the dot, observe the printed dot with a stereomicroscope and mark it as ○ if it is slightly round, or Δ if the shape is slightly distorted.
Irregular shapes were marked as ×.

3) The degree of bleeding is determined by measuring the diameter of 1 nit of printing using a stereomicroscope.
It is expressed as how many times the increase is compared to the ink droplet.

4) Color brightness was determined by visually comparing the color sharpness of the inkjet recorded images, and ranking the best one as 0 and the worst as ×, as ■, ○, △, and ×.

5) Ink absorption is determined by the ability to record clear images without ink flow when recording with four colors of ink.
Others were marked as ×.

Example 2 Using diatomaceous material (Celite 281, trade name, manufactured by Jeongmanpil, average particle size 81 μs) as a porous inorganic pigment, starch and SBR latex as binders, and based on the following composition. A composition for coating T was prepared.

100 parts by weight Starch 3Q //SBR Latex I
Q // Wednesday 800
On the other hand, as a support, the same general apparatus as in Example 1 was used, and the composition described above was coated on the support using a blade coater method at a rate of 10 g/m' of dry coating line. A recording material was obtained by coating and drying by a conventional method.

Table 1 shows the results of evaluating this recording material in the same manner as in Example 1.
Shown below.

Example 3 Heptaolide (trade name: Molecular Sieve 13X, manufactured by Union Showa Co., Ltd., average particle size 1) as a porous inorganic pigment
0-) and starch as a binder, a composition for coating T was prepared based on the following composition.

Seven Oride 100-fold Hidden Department Tenbun
20 tt water
300 tt On the other hand, the same general high-quality paper as in Example 1 was used as the support, and 1120 g of the above coating composition was dried and coated on this support.
/ m' by the blade coater method,
A recording material was obtained by drying in a conventional manner. This recording material was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 Inkjet recording characteristics were evaluated in the same manner as in Example 1 using commercially available art coat paper (trade name: SK Coat, manufactured by Yamakawa Kokusaku Pulp Co., Ltd.) as a recording medium. The results are shown in Table 1. In addition, approximately 150% of the surface of the coating layer of this paper
A scanning electron micrograph at 0x magnification was as shown in FIG.

2

[Brief explanation of the drawing]

FIG. 1 shows the surface of the old coating layer to be recorded according to the present invention.
Figure 2 is a commercially available Artcoat Microscope (page J').

Claims (1)

[Claims] 1. In a recording material in which a coating layer containing a porous inorganic pigment and a binder is provided on the surface of a support, irregular particle shapes of the porous inorganic pigment appear on the surface of the coating layer. A recording material for ink-send recording characterized by: