JPS6063190A - Recording material - Google Patents

Abstract

PURPOSE:To provide an ink jet recording material having a high ink-absorbing property and an appropriate degree of blurring and capable of providing a favorable ink dot shape and a high picture element density, wherein a recording surface has a special structure consisting of a filler and a part of a fibrous base. CONSTITUTION:For example, a coating liquid obtained by dispersing a component consisting mainly of a filler (e.g., silica) 3 and a binder in water or the like is applied to a fibrous base (preferably, a paper treated with a sizing agent or the like to reduce a liquid-absorbing property, or the like), and is dried as speedily as possible to obtain the objective recording material 1 in which the recording surface 1A consists of a part 2 of fibers of the fibrous base material and the filler 3, and the part 2 of the fibers is present in extreme proximity to the recording surface 1A. EFFECT:The diameter of ink dots can be controlled to a desired value by varying the amount of the components in the coating liquid. It is possible to record by using a large picture element area.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material used in an inkjet recording method, which has high ink (recording liquid) absorption, has an appropriate degree of bleeding, and has a good ink dot shape. Moreover, the present invention relates to a recording material for inkjet recording that provides high pixel density.

The inkjet recording method uses an ink ejection method, such as an electrostatic attraction method using a high voltage application or a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, to generate small droplets of ink, which are then flown onto paper, etc. This recording method generates little noise and allows high-speed printing and multicolor printing.

Inks for inkjet recording are mainly water-based in terms of safety and printability, and generally include a recording agent and a liquid medium.

As the recording material used in this inkjet recording method, conventional paper has generally been used. but,
2. Description of the Related Art 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 properties.

As such a recording material for inkjet recording.

1) Ink absorption should be as quick as possible.

2) When ink dots overlap, the ink that adheres later does not flow onto the previous dot, 3) The diameter of the ink dot is the desired size and uniform, and 4) The shape of the ink dot is close to a perfect circle. , and the surrounding area must be smooth; 6) the whiteness must be high; and 7) the coloring components of the ink must have excellent color development. Ru.

On the other hand, when recording on a recording material using the inkjet recording method, generally the image to be recorded (original image) is evenly divided into fine parts, and each unit (pixel) of the finely divided image is The original image is reproduced on the recording material by a method of expressing it with one ink dot or a plurality of ink dots during recording. In such a recording method, in order to provide a sufficient recording density to a recorded image, it is necessary to obtain a sufficient pixel density (recording density for one pixel as a whole). For this purpose, to explain this using an example where one pixel is expressed as one ink dot using the same amount of ink with the same recording agent concentration, the ink dots recorded in one pixel will spread as uniformly over the entire pixel as possible. It is preferable that ink dots be recorded in this way, because generally, when an ink dot with a small diameter is recorded in one pixel, the recording density of the ink dot itself becomes high, but the density of one pixel becomes low. On the other hand, as the diameter of the ink dot increases, the recording density of the ink dot itself decreases, but conversely, the pixel density increases. This is because the pixel density reaches its maximum when the ink dots spread uniformly over the entire pixel. This is because pixel density is mainly defined by the relative relationship between a recorded portion and a non-recorded portion within one pixel.

Further, if recording is performed using a recording material with a higher degree of bleeding, a larger pixel area can be used for recording, and the recording speed can be increased.

Therefore, in addition to meeting the above-mentioned required performance, it is also important that the recording material for inkjet recording has an appropriate degree of bleeding so that the ink dots recorded in a pixel of a predetermined size spread uniformly over the entire pixel. is required.

For example, when ordinary high-quality paper is used as a recording material, it has poor ink absorption properties, making it impossible to obtain a sufficiently large ink dot diameter, the shape of the ink dots being extremely poor, and the desired pixel density being unable to be obtained uniformly. Commercially available non-coated paper
Although the ink absorption is sufficient, the ink runs through the paper fibers and the degree of bleeding is uneven within the paper surface.
It is difficult to control the shape and size of the ink dots, and local variations in ink dot density occur, making it impossible to obtain sufficient pixel density.

It is an object of the present invention to satisfy the above-mentioned requirements, to have high ink absorbency, and to provide suitable bleeding so that ink dots recorded in a pixel of a predetermined size spread uniformly over all four pixels. It has a good ink dot shape.
Another object of the present invention is to provide an inkjet recording material with excellent color development.

The above object is achieved by the present invention as follows.

That is, in the present invention, the recording surface is made up of a mixture of at least a filler and a part of a fibrous base material, and a part of the fibers forming the fibrous base material are located very close to the recording surface. A recording material for inkjet recording characterized by being present in.

The recording material of the present invention is characterized by the unique structure of the recording surface of the recording material that receives ink.

That is, the recording material of the present invention basically has a base material mainly made of a fibrous material and filler particles attached to the surface of the base material. The recording material is coated with the filler particles very thinly scattered and attached to the surface of the substrate to such an extent that the fiber shape of the fibrous material that mainly constitutes the substrate is not completely hidden from the surface of the substrate. A surface is formed, typically as shown in the schematic diagram of FIG.

Part 1a of the recording surface IA of the recording material l of the present invention in FIG.
As shown in the schematic enlarged view 1b, the base material (not shown)
Filler particles 3 are fixed to the surface of the substrate by a binder (not shown). Some portions 2 of the fibers of the fibrous material that mainly constitute the base material (not shown) are lightly covered with filler particles 3, and other portions are in direct contact with the outside world. The filler particles 3 not only lightly cover some of the fibers 2 of the m-ray quality material that mainly constitute the base material (not shown), but also penetrate into the gaps between the fibers 2 . In this way, the filler particles 3 are applied on and over some of the m-fibers 2 constituting the base material to such an extent that the shape of the fiber #I2 is left on the recording surface of the recording material of the present invention. The fibers are fixed so as to fill the gaps, and a portion 2 of the fibers constituting the base material is present very close to the recording surface of the recording material. It should be noted that the recording surface of the recording material of the present invention is formed to such an extent that the shape of the fibers that mainly constitute the base material is left on the recording surface, that is, a part of the fibers that mainly constitute the base material. may be uniformly covered with the filler particles 3 to the extent that they are present in the very vicinity of the recording surface of the recording material.

FIG. 2 shows 150 mm of the recording surface of an example of the recording material of the present invention.
This is a scanning electron micrograph with a magnification of 1.5 times, in which the filler particles are fixed to such an extent that the shape of the fibers of the base material remains on the recording surface, and some of the fibers that mainly make up the base material are attached to the recording surface. The characteristic state of the recording surface of the recording material of the present invention, which is present in the very vicinity of the recording surface of , is clearly shown.

On the other hand, FIG. 3 is an electron micrograph at the same magnification of the recording surface of a conventional recording material (trade name: Inkjet Paper L, manufactured by Mitsubishi Paper Industries, Ltd.). FIG. 3 clearly shows the structure of the recording surface of this recording material in which countless pulp fibers overlap, and it is clearly distinguished from the recording material of the present invention.

In this way, the recording surface IA of the recording material of the present invention is, so to speak, a mixture of at least the filler particles 3 and some of the fibers 2 mainly constituting the base material, and the ink is When recording is performed, the ink adhering to the recording surface IA of the recording material is absorbed by the surface portion where #ll fibers 2 and filler particles 3 are mixed together. Then, it is hardly absorbed into the fiber layer inside the recording material, that is, it is hardly absorbed in the thickness direction of the recording material, and spreads horizontally over the surface portion. For this reason, the recording material of the present invention has a high degree of smearing, and can record sufficiently large ink dots within the pixels of the aforementioned predetermined size.

As the base material made of at least a fibrous material of the recording material of the present invention, it is appropriate to use paper, but cloth, synthetic paper, etc. can also be used. In addition, in order to suppress the ink absorption in the thickness direction of the recording material as described above, it is recommended to use a base material made of fiber #I material whose liquid absorption is suppressed by a method such as sizing. is preferable,
Further, the base material may have a suitable support such as a resin film.

On the other hand, one of the other components that basically constitutes the recording surface l^ of the recording material of the present invention is the filler 3 which is fixed to the surface of the base material mainly by a binder.

Examples of the filler include silica, clay, talc, carrion, diatomaceous mineral, calcium carbonate, calcium sulfate,
Examples include satin white, silicone aluminum, alumina, and zeolite, and one or more of these may be used.

The fiber Ia constituting the base material is placed on the recording surface IA of the recording material.
Filler particles 3 are placed on the P material fibers to such an extent that the shape of 2 remains.
In order to fix the filler so as to fill the spaces between them, and to provide good ink absorbency and degree of bleeding to the recording surface of the recording material, the particle size of the filler used should be between 0.05u and 50μ. If the particle size of the filler is too large, the degree of ink bleeding in the horizontal direction of the recording material will be uneven, and the size of the dots and This is not preferable because it becomes difficult to control the shape.

Furthermore, if a porous filler is used as the filler particles 3,
The ink attached to the surface of the recording material penetrates into the porous filler, and the recording agent components of the ink (such as dyes and pigments) are adsorbed by the porous filler, resulting in good color development. can be obtained.

On the other hand, examples of the binder for fixing the filler to the surface of the base material include starch, gelatin, casein, gum arabic, alginic butysodic soda, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, and polyacrylamide. Water-soluble polymers: synthetic resin latex such as synthetic rubber latex, polyvinyl butyral, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polymethyl methacrylate, polyvinyl formal, melamine resin.

Examples include organic solvent-soluble resins such as polyamide, phenol resin, polyurethane, and alkyd resin. In addition, the surface portion of the recording material of the present invention may contain other pigments such as plastic pigments, dispersants, fluorescent dyes, PH adjusters, erasers, etc. in addition to the above-mentioned fillers, to the extent that the effects of the present invention are not impaired. Various additives such as foaming agents, lubricants, preservatives, and surfactants can also be mixed.

The recording material of the present invention can be obtained by applying a coating liquid prepared by dispersing ingredients mainly consisting of these fillers and a binder in a medium such as water, using a roll coating method, a rod bar coach ink method,
It can be manufactured by coating on a substrate by a spray coating method, an air knife coating method, etc., and then drying it as quickly as possible.

As for the mixing ratio of the filler and the binder in the coating liquid, it is generally appropriate that the binder is 10 to 15 parts by weight per 100 parts by weight of the filler, and when the average particle size of the filler is large, Good results are obtained by using as little binder as possible. The coating amount of components including fillers, binders, etc. that are fixed on the substrate is determined by the desired dot diameter and the amount of ink that forms one ink dot and the size of the pixel in which the ink dot is recorded. Selected by. That is, by reducing the coating amount of these components, larger ink dots can be obtained. The coating amount is usually selected from a range of about 1 to 30 g/rn' (dry coating amount).

In this way, the recording material of the present invention, which has a unique surface condition on the recording surface, has high ink absorption properties, and also allows ink dots recorded in pixels of a predetermined size to spread uniformly over the entire pixel. Since it has a suitable degree of bleeding and a good ink dot shape, it is an inkjet recording material that can provide sufficient pixel density and has excellent color development.

Furthermore, by using the recording material of the present invention, when the same amount of ink is used, by changing the amount of coating components, the diameter of the recorded ink dot can be adjusted to a desired size that is adapted to the width of the pixel. It became possible to control the size. Furthermore, compared to conventional recording materials, larger ink dots can be obtained, recording can be performed using a larger pixel area, and the recording speed can be increased.

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

Example 1 Light calcium carbonate (average particle size: lμs) as a filler
) with polyvinyl alcohol and SBR as the binder.
A coating composition was prepared using latex based on the following composition.

Light calcium carbonate 100 parts by weight Polyvinyl alcohol 25 SBR latex 5 tt Water 5 Q O// On the other hand, as a fibrous base material, general high-quality paper (basis weight 85 g/m '
), the above-mentioned coating composition was coated onto this support by a blade coater method at a dry coating weight of 2 g/m'', and dried by a conventional method to obtain a recording material. FIG. 2 shows a scanning electron micrograph of the recording surface of the recorded recording material obtained at a magnification of 150 times.

For this recording material, the following four colors of ink were used, the droplet diameter was 90 μs, and the pixel size was 300 x 300.
Color inkjet recording was performed under the following recording conditions, and the recording characteristics of the recording material were evaluated.

Yellow ink (composition) C, 1, acid yellow 23 2 parts by weight diethylene glycol 301/water 7Q /1 Magenta ink (composition) C, 1, acidlend 92 2 parts by weight diethylene glycol 30 "Water 70" Cyan ink (composition) C, 1. Direct Blue 86 2 Parts by weight Diethylene glycol 30〃 Water 7Q // Black ink (composition) G, 1. Direct Black 19 2 Parts by weight Diethylene glycol 30〃 Water 70 // The evaluation results of the recording characteristics of the recording material are shown in Table 1. show.

When evaluating the recording characteristics in Table 1, l) Pixel density was measured by measuring the reflective optical density when recording was performed on all pixels using a photographic densitometer NLM-5TD-Tr (manufactured by Narumi Shokai).

2) The dot shape was determined by observing the printed dots with a stereomicroscope, and 01, 01, and 01, where the circle was slightly distorted, △,
The amorphous one was designated as X.

3) The degree of bleeding is determined by measuring the diameter of the printed dot with a stereomicroscope of 711.
It is expressed as how many times the ink droplet has increased.

4) Color clarity was determined by visually comparing the color clarity of the inkjet recorded images, and ranking the best as O1 and the worst as ×, and ranked as @, O1Δ, and ×.

5) Ink absorption is rated as 0 if there is no ink flow and the image is clear when recording two colors of ink overlappingly.
The rest were marked as X.

Example 2 A coating composition was prepared based on the following composition using silica (trade name: Nibusil E220A, manufactured by Nippon Silikani Industries, average particle size 1 (lu) as a filler and starch and SBR latex as a binder). I made something.

Silica 100 Parts by weight Starch 3Q tt SBR latex 10 Water 300 On the other hand, the same general high-quality paper as in Example 1 was used as the fibrous base material, and the above coating composition was dried and coated onto this support. It was applied by a blade coater method at a rate of 2 g/m' and dried by a conventional method to obtain a recording material.

A scanning electron micrograph of the recording surface of this recording material at a magnification of 150 times was almost the same as that obtained in Example 1 shown in FIG.

The recording characteristics of this recording material were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 Carrion (average particle size 2μ) was used as filler particles,
A coating composition was prepared based on the following composition using casein as a binder.

Carrion 100 parts by weight Casein 20/l Water 500 On the other hand, the same general high-quality paper as in Example 1 was used as the fibrous base material, and the dry coating amount of the above coating composition was applied onto this support. The recording surface of this recording material was coated with a blade coater method at a rate of 5 g/rn', dried in a conventional manner, and coated with liquid fertilizer. It was almost the same as that obtained in Example 1.

The recording characteristics of this recording material were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 The IT value of inkjet recording characteristics was determined in the same manner as in Example 1 using commercially available inkjet paper (trade name: Inkjet Paper, manufactured by Mitsubishi Paper Mills Co., Ltd.) as a recording material. The results are shown in Table 1, and a scanning electron micrograph of the recording surface of this inkjet paper is shown in FIG. 3 at a magnification of 150 times.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram including a schematic enlarged portion of the recording surface of an example of the recording material of the present invention, and FIG. The photomicrograph (FIG. 3) is a scanning electron micrograph of the recording surface of conventional inkjet paper at a magnification of 150 times. In the figure, l is the recording material, IA is the recording surface of the recording material, tb is a partially enlarged part of the recording surface, 2 is a part of the fiber that mainly constitutes the base material, 3 is filler particles. Figure 1 No. 2 Proceedings Amendment (Method) February 29, 1980 Director General of the Patent Office 1. Indication of the case 1981 Patent Application No. 171377
No. 2, Name of the invention Recording material 3, Person making the amendment Relationship to the case Patent applicant (100) Canon Co., Ltd. 4, Agent address: 1-9-20-5 Akasaka, Minato-ku, Tokyo, Order for amendment Date of shipment: January 31, 1982 (1) "Recorded surface 1
The description "Scanning electron micrograph at 50x magnification" has been corrected to "Photograph substituted for a drawing taken with a scanning electron microscope at 150x magnification to show the particle shape of the filler particles on the recording surface." (2) On page 20, line 6 of the specification, the statement "This is a scanning electron micrograph of 150 times the recording surface." This is a photo taken in place of a similar drawing taken using a microscope.'' The statement has been corrected.

Claims (1)

[Claims] The recording surface is made of a mixture of at least a filler and a part of a fibrous base material, and m#I forming the fibrous base material
1. A recording material for inkjet recording, characterized in that a part of the recording material exists very close to the recording surface.