JPH08310114A - Production of image receiving medium, image receiving medium produced thereby and image forming method using image receiving medium - Google Patents

Abstract

PURPOSE: To obtain an image receiving medium capable of obtaining an image free from beading and an ink receiving layer free from coating flaw and to form an image using the image receiving medium. CONSTITUTION: In a method for producing an image receiving medium by applying a coating soln. containing pigment and a water-soluble binder to a support and drying the coated support to form an ink receiving layer, a drying process wherein the wind velocity of the vertical component to a coating surface of the flow of air used in the drying of the coating soln. is 2.5m/sec or less and that of the horizontal direction is 4.0m/sec or less is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a recording medium suitable for recording using an aqueous ink and an image forming method using the recording medium obtained by the method, and particularly, beading occurs. The present invention relates to a difficult recording medium manufacturing method and an image forming method using the recording medium obtained by the manufacturing method.

[0002]

2. Description of the Related Art In recent years, an ink jet recording system is one in which minute droplets of ink are ejected according to various operating principles and adhered to a recording medium such as paper to record images, characters, etc. It is characterized by high speed and low noise, easy multicoloring, great flexibility in recording patterns, and no need for development and fixing, and is rapidly spreading in various applications such as information equipment as various image recording devices. Furthermore, images formed by the multicolor ink jet system can be recorded in comparison with multicolor printing by the plate making system and printing by the color photographic system. Since it is cheaper than multicolor printing and printing, it is being widely applied to the field of full-color image recording. The recording apparatus and recording method have been improved with the improvement of recording characteristics such as high-speed recording, high-definition, full-color recording, etc. It's coming.

In order to meet such requirements, various types of recording media have been proposed in the past. For example, JP-A-55-5830 discloses an ink jet recording paper having an ink-absorptive coating layer provided on the surface of a support, and JP-A-55-51583 discloses a non-ink-jet recording paper. An example using amorphous silica is also disclosed in JP-A-55-55.
JP-A-146786 discloses an example using a water-soluble polymer coating layer.

In recent years, recording media having a coating layer using alumina hydrate having a boehmite structure have been proposed, for example, US Pat. Nos. 4,879,166 and 5;
No. 104730, JP-A-2-276670 and JP-A-3
No. 275378, No. 3-281384, and No. 5-32037.

Further US Pat. No. 4,374,804
No. 5,104,730, JP-A-58-110287, JP-A-1-97678, and JP-A-2-27667.
As disclosed in Japanese Patent Laid-Open No. 1-37456 and Japanese Patent Laid-Open No. 4-37576, it has been practiced to form an ink receiving layer having a multilayer structure by using a silica or alumina material.

However, both of the proposals are
Resolution, image density, color, color reproducibility, ink adsorption,
This is related to improvement in transparency, etc., and even with such a proposal, beading cannot be improved or eliminated.

Here, beading generally tends to occur when the speed of ink absorption into the ink receiving layer is slow, and is visually recognized as color unevenness resembling a small circle. The size is generally about 0.2 to 2.0 mm, but there are cases where the size is out of the range. The name derives from the fact that the shape is generally beaded.

The phenomenon of beading is that the ink remaining on the surface of the ink receiving layer gathers or repels as the ink remains on the surface of the ink receiving layer because the absorption speed of the ink is slow in the process of absorbing the ink into the ink receiving layer. Move around,
This creates high and low parts in the color density of the ink.
When observed after the ink is fixed, most of the areas where the ink density is low are small circles, and frequently occur at locations where the ink ejection amount is large.

Regarding the ink absorption speed, beading is more likely to occur when the ink absorption speed is slower, but when the ink absorption speed is too slow, the amount of ink remaining on the surface of the ink receiving layer is large and repulsion or deviation does not occur, resulting in beading. It may not occur. However, in this case, the ink largely flows or is mixed with the ink of a different color in the vicinity, and the image is greatly disturbed.

The frequency of this beading also differs depending on the type of substrate on which the ink receiving layer is formed.

When the substrate has liquid absorbability, even if the solvent of the coating liquid is absorbed from the time of coating and the drying speed is increased to some extent,
Since the nonuniformity of the binder in the coating film is not remarkable, beading is less likely to occur. Further, in the image forming method, in the case of a substrate having a high liquid permeability and absorptivity even when the ink is ejected to the ink receiving layer, the substrate itself can absorb the ink, resulting in an increase in the ink absorption speed. Become.

As described above, it is possible to prevent beading from occurring depending on the type of the substrate. However, the substrate of the ink jet image receptor, whether transparent or opaque, is plastic, metal, glass, ceramic sintered body, coated paper. There is also a strong need for materials that have a high surface gloss, such as art paper, that have low liquid permeability and absorbency.

Regarding the ink absorbency of a recording medium having an ink receiving layer containing a pigment and a binder as a main component, the above-mentioned prior art has been improved from the viewpoint of pore volume and pore radius. Is not described, and the beading is not sufficiently solved only by considering both the pore volume and the pore radius.

For example, US Pat. No. 5,104,730
No. 2,276,670, and No. 2-27667.
No. 1 and No. 3-275378 disclose recording media having an average pore diameter of 10 to 30 angstroms and a narrow pore diameter distribution. In this pore diameter distribution, dye adsorption is good. The solvent absorbency is insufficient and beading occurs.

Further, in Japanese Patent Laid-Open No. 3-281384, an alumina hydrate which forms a columnar bundle having an aspect ratio of 3 or less and oriented in a fixed direction, and the alumina hydrate are used. A method for forming an ink receiving layer having good absorbency and color is disclosed. However, since the alumina hydrate particles are oriented and densely packed, the gap between the alumina hydrate particles in the ink receiving layer is likely to be narrowed. Therefore, there is a tendency that the pore diameter is biased toward the narrow side and the pore diameter distribution is narrowed. As a result, there is a problem that beading occurs.

In addition, the method of increasing the pore volume of the pigment to improve the ink absorbability impairs the transparency of the ink image-receiving layer to cause haze, thereby lowering the color density of the image.

Japanese Patent Laid-Open No. 1-133779 discloses a beading countermeasure by surface modification, but it is a non-porous image receptor and not a technical disclosure relating to a porous image receptor using a pigment. .

As described above, in spite of the improvements in the pigment and the formulation of the selective coating solution for the binder as the prior art, the present situation is that the effect of preventing the beading is not great.

Regarding the beading of the recording medium, what has been studied from the viewpoint of the manufacturing method is not well known, and in particular, the relationship between the drying conditions and the ink jet recording characteristics in the manufacturing method is almost unknown. It is the current situation that it has not been done.

In Japanese Patent Laid-Open No. 63-170075, the drying conditions of the coating layer are shown by temperature and its gradient.
This is a technical disclosure for the purpose of film-forming property such as crack prevention, and there is no description of beading.

[0021]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems of the prior art, and provides a stable recording medium having good image suitability and less beading. An object of the present invention is to provide a manufacturing method and an image forming method using a recording medium manufactured by the manufacturing method.

[0022]

The above object can be achieved by the following means.

That is, according to the present invention, a coating liquid containing a pigment and a water-soluble binder is applied to a substrate and dried to form an ink receiving layer in a method for producing a recording medium. The method for producing a recording medium is characterized in that it has a drying step in which the flow of the gas used for is a component vertical to the coated surface, a wind speed is 2.5 m / sec or less, and a horizontal component is 4.0 m / sec or less. Is a suggestion,
The substrate is a liquid non-absorbent substrate, the substrate is a paper having a Steckigt sizing degree of 100 seconds or more,
The temperature of the gas is in the range of 70 to 150 ° C., the pigment contains a metal oxide, and the pigment is an alumina hydrate.

Further, the invention proposes a recording medium manufactured by the manufacturing method of the present invention, wherein the substrate is a substrate having no liquid absorbency, and the substrate has a Steckigt sizing degree. It includes paper for 100 seconds or more, the temperature of the gas is in the range of 70 to 150 ° C., the pigment contains a metal oxide, and the pigment is alumina hydrate.

Further, the present invention is characterized in that the above recording medium is used as a recording medium in an image forming method in which ink is ejected from fine pores and applied as a droplet to the recording medium for printing. An image forming method is proposed.

[0026]

According to the present invention, an image without beading can be obtained by an ink jet recording system, and a recording medium having an ink receiving layer without coating defects can be obtained.

The present invention will be described in more detail below.

The basic idea of the present invention is to prevent sudden drying of only the surface of the coating layer in the drying step.

The coating liquid mainly contains a pigment and a water-soluble binder, but when rapid drying occurs on the surface of the coating layer,
A film of pigment and water-soluble binder is formed. The faster the drying rate of this coating, the higher the proportion of water-soluble binder. It is considered that the water-soluble binder moves to the region where the concentration of the water-soluble binder is partially increased during the drying process so that the water-soluble binder gathers from the diluted portion. Therefore, if the drying process is performed under such a condition that the surface condition is rapidly dried, the pigment / binder (hereinafter referred to as P / B) set by the formulation of the coating liquid collapses in the vicinity of the surface of the ink receiving layer, and the setting is performed. The binder ratio is higher than the ratio. In addition, the binder also moves on the surface of the ink receiving layer, and the binder becomes sparse and dense. This densification is increased by unevenness and turbulence of the dry gas flow. When there is less binder compared to the pigment, the sparse densification of this binder is emphasized.

When P / B is low, the film formability is good, but the ink absorbency is low, and when P / B is high, the ink absorbability is good, but the film formability is low and cracks may occur. It is known that powder drop occurs. When the drying rapidly occurs on the surface of the ink receiving layer, P / B becomes low on the surface, the ink absorbency is lowered, and the ink absorbing speed becomes uneven in a narrow area, which is considered to cause beading. . When the amount of the coating liquid applied to the base material during coating is large, beading tends to be remarkable, which is considered to support this idea.

The movement of the pigment in the absence of the binder will be described below.

When rapid drying is carried out in the absence of a binder, the surface of the coating layer forms a film of fine particles. Even if the inside is not dried, a film is formed on the surface. When it is completely dried as it is, the vicinity of the surface is more dense than the inside due to finer particles, and this becomes more remarkable as the pigment used is smaller. Since there is no binder, the above film has a high ink absorption rate and does not cause a problem of beading, but it can be seen that rapid drying from the surface is not so preferable from the viewpoint of the movement of the pigment. Thus, the rapid drying of the surface deteriorates the important property of ink absorption. The present invention aims to suppress rapid drying of the coating layer surface in consideration of the drying speed.

Preferred embodiments of the present invention will be described below with reference to the drawings.

The recording medium obtained by the production method of the present invention has a constitution in which an ink receiving layer 2 mainly containing a pigment and a water-soluble binder is formed on a substrate 1 as shown in FIG.

The substrate preferably has no or very low liquid absorbency, and even if the solvent of the coating liquid permeates and absorbs, its speed is 1 in terms of size expressed by paper evaluation.
A value of 00 seconds or more is suitable in the present invention. In the case of a substrate with high liquid absorption, it absorbs the coating liquid,
Beading is unlikely to occur, and there is no problem of beading under the conditions of the present invention, but on the contrary, the production efficiency will decrease. Further, it generally tends to be lower than the surface glossiness that occurs when the coating liquid is dried without being absorbed.

The shape and physical properties of the substrate are not limited to those of films, sheets, blocks and the like, and are not limited to transparent and opaque.

Specific examples include thermoplastics such as transparent films, sheets and plates of polyester, polystyrene, polyvinyl chloride, polymethylmethacrylate, cellulose acetate polyethylene, polycarbonate, etc., and titanium white for the thermoplastics. , Those filled with carbon and pigment, and the opaque sheet made by fine foaming. Also, various resin materials and composite materials can be used. In addition, thin films such as metals and metal vapor deposition films, ceramics, sintered bodies, or thin films formed by sputtering metal oxides or ceramic materials,
The surface is poly coated, laminated wood or paper,
Examples include resin-coated paper, poly-coated paper, and synthetic paper.

Among the liquid-absorbent papers, cast-coated papers, calendered art papers, printed papers, and other papers having a slow absorption speed are suitable under the conditions of the present invention. The conditions for this substrate are a Steckigt sizing degree (commonly sizing degree JISP-8122), which is one of the evaluation methods for paper, and a basis weight of 100 g / m ² for 100 seconds or more. If the absorbency of the coating liquid is low, it can be handled in the same manner as plastics and the like, so there is no particular upper limit. Stekihit size is 100
As mentioned earlier, if the time is less than a second, the coating liquid is absorbed and the ink absorbency is also good, so the conditions such as the coating amount also change and production is possible other than the conditions of the present invention, further increasing the production efficiency. be able to. However, when the Steckigt sizing degree is less than 10 seconds, the coating liquid is absorbed too well, and there is a risk that the coating liquid strikes through and causes defective coating. These substrates may be provided with a surface treatment such as corona treatment or an easily adhesive layer as an undercoat layer in order to improve the adhesion to the ink receiving layer. However, the easy-adhesion layer should not be a layer that absorbs a large amount of the coating liquid or accelerates the ink absorption rate of the ink receiving layer.

In order to prevent curling, waviness and the like of these substrates, a curl preventing layer such as a resin layer or a pigment layer may be provided on the back surface of the substrate or a predetermined portion.

Any of these substrates may be used as long as it has heat resistance under the drying conditions in the production method of the present invention.
Foaming, ignition, cutting, peeling, deformation that does not withstand use, expansion and contraction,
Any one may be used as long as it does not cause discoloration or the like.

The coating liquid used in the present invention mainly comprises a pigment and a water-soluble binder.

Examples of the pigment include calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titania, zinc oxide, zinc carbonate, aluminum silicate, alimina hydrate, silicic acid, sodium silicate, magnesium silicate, and silica. Inorganic pigments such as calcium acid and silica,
Organic pigments such as plastic pigments, urea resin pigments,
And these can be used in combination.

Particularly preferred pigments from the viewpoint of resolution suitability such as ink absorbency and resolution characteristics are alumina hydrate,
It is silica. Alumina hydrate is more preferable as a pigment used in the ink receiving layer, because it has a positive charge, so that the dye in the ink can be fixed well and an image with high gloss and high image density and good color development can be obtained.

The alumina hydrate used in the present invention is represented by the following general formula.

[0045]

Embedded image In the formula, Al ₂ O _3−n (OH) _2n · mH ₂ O, in which n represents an integer of 0, 1, 2 or 3, and m represents 0 to 10, preferably 0 to 5 Represents the value of. m
In many cases, H ₂ O represents a detachable aqueous phase that does not participate in the formation of the crystal lattice, and therefore m can take a non-integer value. Also, when this type of alumina hydrate is calcined, m can reach a value of zero.

Alumina hydrate suitable for carrying out the present invention is an amorphous alumina hydrate as analyzed by X-ray diffraction method. In particular, Japanese Patent Application Nos. 5-125437 and 5-12.
No. 5438, No. 5-125439, No. 6-11457.
The alumina hydrate described in No. 1 is preferably used.

As the silica, natural silica, synthetic silica, amorphous silica and the like, and chemically modified silica compounds can be used, but silica having a positive charge is particularly preferable. CT-10
0 "(manufactured by Asahi Denka Co., Ltd.)," Snowtex A "
K ”(manufactured by Nissan Chemical Industries, Ltd.) and the like are commercially available,
It is available and is preferably used.

In Japanese Patent Publication No. 4-19037, an ink jet recording medium having a positively charged silica (cationic colloidal silica) contained in the ink receiving layer has both water resistance and light resistance. It is described that the characteristics are satisfied. However, there is no description of the beading relationship, and even with such a technique, beading cannot be improved or eliminated.

However, the present invention does not deny the prior art at all, and the use of the pigment of the invention for the purpose of improving ink absorbency, image quality and image characteristics is not limited.

In the recording medium of the present invention, the binder used in combination with the pigment is preferably a water-soluble polymer substance. For example, polyvinyl alcohol or a modified product thereof (cationic modification, anion modification, silanol modification), starch or its modification (oxidation, etherification),
Gelatin or a modified product thereof, casein or a modified product thereof, cellulose derivative such as carboxymethyl cellulose, gum arabic, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, SBR latex, N
BR latex, conjugated diene-based copolymer latex such as methyl methacrylate-butadiene copolymer, functional group-modified polymer latex, vinyl-based copolymer latex such as ethylene-vinyl acetate copolymer, polyvinylpyrrolidone,
Maleic anhydride or a copolymer thereof, an acrylic acid ester copolymer and the like are preferable. These binders can be used alone or in combination of two or more.

The mixing ratio of the pigment and the binder is 3/1 to 30/1 by weight ratio (P / B), more preferably 5/1.
It can be arbitrarily selected between ˜20 / 1. When the binder ratio is less than the above range, the mechanical strength of the ink receiving layer is insufficient, and cracks and powder falling occur. When the binder ratio is more than the above range, the pore volume of the pigment is large. To reduce ink absorption.

If necessary, the coating liquid containing the pigment and the binder may include a dispersant, a thickener, a pH adjuster, a lubricant, a fluidity modifier, a surfactant, an antifoaming agent, a water resistant agent, and an inhibitor. A foaming agent, a release agent, a foaming agent, a penetrant, a coloring dye, a fluorescent whitening agent, an ultraviolet absorber, an antioxidant, an antiseptic, and an antifungal agent can be added as necessary.

As the water-proofing agent, any known material such as halogenated quaternary ammonium salt and quaternary ammonium salt polymer can be freely selected and used.

The above-mentioned materials can be used for the preparation of the coating liquid, but since a water-soluble binder is used,
Water is preferable as the solvent, and water is also preferable from the viewpoint of dispersing the pigment in the coating liquid.

An organic solvent can be mixed and added as long as it does not adversely affect the pigment and the binder. An organic solvent can be added for the purpose of defoaming effect, adjustment of viscosity, dissolution of various additives, adjustment of drying speed during coating and the like. However, it is necessary to pay attention to the influence on the image, the coating property during coating and drying, the dispersibility of each material, etc.
% Or less, and 30% or less in a preferable range.

The solid content concentration of the coating liquid is preferably 10 to 40% by weight, more preferably 15 to 30% by weight, and particularly preferably 15 to 25% by weight. When the solid content concentration is less than 10% by weight, a large amount of the coating liquid needs to be placed on the substrate in order to obtain an ink receiving layer having a desired thickness, resulting in inefficient drying and beading. Easier to do. Further, when the solid content concentration exceeds 40% by weight and the solid content concentration is high, the viscosity becomes high and handling is difficult, and dispersion, defoaming and coating are hindered.

The viscosity of the coating solution is 10 to 1000 cps, especially 40 to 1,000, although it depends on the solid content concentration and the coating method.
600 cps is preferable, 100 to 300 cps is preferable, and 100 to 200 cps is good. However, even if it is out of the above range, coating can be performed depending on the coating method.

The dispersion of the coating liquid depends on the equipment used, the shear strength at the time of dispersion, the dispersion time, and the heating temperature.
It is possible to adjust the particle size distribution and the interaction between the binder and the pigment, which makes it possible to adjust the particle size of the coating liquid and the characteristics of the ink receiving layer (ink absorption rate, absorption amount, glossiness, etc.).

A conventionally known dispersion method can be applied to the dispersion of the coating liquid. For example, a stirrer, an attritor, a dissolver, a high-speed shearing stirrer, a homogenizer, an ultrasonic homogenizer, a high-pressure homogenizer (Gorin emulsifier, etc.), a paint shaker, a ball mill, a sand mill and the like.

The prepared coating liquid is coated on a substrate and dried to form an ink receiving layer. Coating methods include blade coating method, bar coating method, air knife method, roll coating method, brush coating method, gravure coating method, kiss coating method, extrusion method, slide hopper (slide bead) method, die coating method, comma coating method. Method, curtain coat method,
A spray method or the like can be used.

The coating amount of the dispersion liquid is a dry solid content of 0.5 to
65 g / m ^2, more preferably, is a 5~55g / m ^2, good ink absorbency, resolution, to obtain a stable film forming properties, 15Myuemu～55myuemu, preferably 20μm~5
There is a need to have an ink receiving layer thickness of 0 μm, especially 25-45 μm. The greater the amount of coating liquid applied during coating,
Since the occurrence of beading becomes remarkable, the above conditions are preferable.

Regarding the drying conditions at the time of coating, a rapid drying method is not preferable. A hot air dryer is used for the drying path of a general coater. Drying temperature is 70 ° C-150
C, preferably 80 to 130 ° C. When the temperature is low
Beading tends to be less likely to occur, but longer drying times require longer drying paths. If you increase the coating amount,
When the temperature rises to a high temperature, problems such as heat resistance of the substrate and rapid drying of the coated surface occur, as well as excessive heating of the ink receiving layer. Even after the ink receiving layer has dried sufficiently,
This is because if the drying is continued excessively, the ink absorbency may decrease. Regarding the temperature, JP-A-6
The temperature gradient described in 3-1705 may be provided.

Drying on the heated substrate increases as the wind speed increases. When a drying gas is discharged vertically to the substrate coated with the coating liquid, the drying speed can be controlled to some extent by measuring and controlling the flow velocity of the drying substrate (hereinafter referred to as wind speed). It will be possible.

However, the flow of the drying gas flows parallel to the coating surface in the vicinity of the coating surface. This flow becomes faster toward the edge of the substrate and closer to the discharge boundary of the drying gas to the coated surface.

FIG. 2 is a conceptual diagram showing the flow of the drying gas. The velocity of the drying gas is 2.
When the range is 5 m / sec or less and 0.1 m / sec or more, and 4.0 m / sec or less and 0.2 m / sec or more in the horizontal direction, beading can be suppressed and drying can be performed.
If the flow of the drying gas exceeds the above speed, the surface of the coating layer is dried more quickly, and the ink absorption is lowered and the beading occurs. Further, when the flow rate of the drying gas is slower than the above condition range, problems such as poor drying and long drying time occur. The temperature of the drying gas at this time is within the above temperature range.

The wind velocity is 1 cm above the substrate in the vertical direction with respect to the substrate and 0.5 from the substrate in the horizontal component.
It is measured in cm. Regarding the horizontal component, when the substrate moves, the value obtained by adding the moving speed to the measured wind speed must be 4.0 m / sec or less.

Further, if the drying stage is divided into several stages, the wind velocity may be changed in each stage.
However, in the drying step until the binder does not move in the ink receiving layer, the above wind speed conditions must be observed, and the drying conditions may be strengthened thereafter.

If the amount of air is first increased under the drying conditions after coating, the coating liquid will be disturbed by the wind in addition to beading, and coating defects and cracks will easily occur.

Under the conditions of the present invention, such defects can be eliminated. A general anemometer can be used to measure the wind speed, but a device equipped with a temperature correction function or a device that is not affected by temperature is preferable.

The ink used in the image forming method of the present invention mainly contains a coloring material (dye or pigment), a water-soluble organic solvent and water. As the dye, for example, a water-soluble dye represented by a direct dye, an acid dye, a basic dye, a reactive dye, an edible pigment, etc. is preferable, and fixing property, color developability, vividness, stability in combination with a recording medium are preferable. Any material can be used as long as it gives an image satisfying the required performance such as light resistance.

The water-soluble dye is generally used by dissolving it in water or a solvent consisting of water and an organic solvent, and these solvent components are preferably a mixture of water and various water-soluble organic solvents. Is used, but the water content in the ink is 20 to 90% by weight, preferably 60 to 90% by weight.
It is preferable to adjust so as to fall within the range.

Further, a solubilizing agent may be added to the ink in order to dramatically improve the solubility of the water-soluble dye in the solvent. Further, in order to improve the properties, additives such as a viscosity modifier, a surfactant, a surface tension modifier, a pH modifier, a specific resistance modifier, a storage stabilizer including light resistance and durability can be added and used. .

An ink jet recording method is preferable as an image forming method for recording by applying the above ink to the recording medium. In the recording method, the ink is effectively separated from the nozzle so that the ink is recorded on the recording medium. Any method can be used as long as it can be applied. In particular, JP-A-54-599
In the method described in Japanese Patent No. 36, the ink-jet method in which the ink subjected to the action of thermal energy causes a rapid volume change, and the action force due to this state change ejects the ink from the nozzle can be effectively used. it can.

[0074]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. <Example 1> Alumina hydrate was used as a pigment. Specific surface area and pore volume are 200.2 m ² / g,
It was 0.71 ml / g.

The specific surface area is the BET specific surface area and was calculated using the method of Bruauer et al.

The pore volume was measured by a nitrogen adsorption / desorption method after degassing at 120 ° C. for 24 hours (Autosoap I, manufactured by Cantachrome).

The manufacturing method is described in US Pat. No. 42422.
Aluminum dodoxide is produced by the method described in No. 71. Next, the aluminum alkoxide was hydrolyzed by the method described in US Pat. No. 4,202,870 to produce an alumina slurry. Water was added to this alumina slurry until the solid content of alumina hydrate reached 7.9%. The pH of the alumina slurry was 9.5.
The pH was adjusted to 6.8 by adding a 3.9% nitric acid solution.
This was aged at 110 ° C. for 6 hours to obtain a colloidal sol. Alumina hydrate obtained by spray drying this colloidal sol at 75 ° C. was used.

This alumina hydrate was dispersed in ion-exchanged water, and then polyvinyl alcohol (Gothenol NH-1
8: An aqueous solution of ion-exchanged water in which Nippon Synthetic Chemical Industry Co., Ltd. was dissolved was added. At this time, the amount of solids of alumina hydrate / the amount of solids of polyvinyl alcohol (pigment / binder = P / B) was measured and added so as to be 13/1.
After mixing and stirring, dispersion treatment was performed to obtain a coating liquid. This coating solution was applied to resin-coated paper (thickness: 238 μm, basis weight: 249.8).
g / m ² ) and dried in an oven at 100 ° C. for 10 minutes. At this time, a fan was rotated in the oven to blow air on the coated surface so that the wind speed was 0.8 m / sec in the vertical direction and 0.8 m / sec in the horizontal direction. 36μ when dried
An ink receiving layer having a thickness of m was obtained. Table 1 shows the drying conditions.
The evaluation results are shown in Table-2.

The wind speed is an electronic anemometer (5K-27V: manufactured by Co., Ltd.)
Sato measuring instrument) was used for the measurement. <Example 2> The coating liquid used in Example 1 was used as a transparent polyester film (manufactured by Toray Industries, Inc., Lumirror T, thickness 100 μm).
m). A die coating method was used for coating. Drying at 130 ° C., coating speed 12 m / min, wind speed 2.5 m / sec in the direction vertical to the coating surface, and 3. in the horizontal direction.
It was 7 m / sec. The thickness of the ink receiving layer is 35 μm
I got Table 1 shows the drying conditions, and Table 2 shows the evaluation results.

The wind speed is an electronic anemometer (SK-57AD:
Sato Keiki Co., Ltd. was used. <Example 3> Using the coating liquid used in Example 1,
Cast coated paper (basis weight 25.6 g / m ² , size degree 3
00 seconds or more). The coating method and drying conditions were the same as in Example 2.

The ink receiving layer had a thickness of 33 μm. Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Example 4> The coating liquid used in Example 1 was used as a white polyester film (manufactured by Toray Industries, Inc., Lumirror X-21, thickness 1).
00 μm). The coating method was a kiss coat method, and the drying temperature was 130 ° C. Coating speed 10m / min, wind speed 1.8m / sec in vertical direction, 2.8m in horizontal direction
/ Sec. The ink receiving layer had a thickness of 34 μm.

Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Comparative Example 1> After applying the same coating solution, base material and coating method as in Example 1, a dryer (household, output 120
0 W) was dried for two minutes under the conditions of vertical component of 3.4 m / sec and horizontal component of 5.0 m / sec. The drying temperature was 70 ° C. The thickness of the ink receiving layer was 35 μm. Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Comparative Example 2> The same coating solution, base material and coating method as in Example 2 were used for coating. Vertical component 7.0m /
The condition was changed to 11.0 m / sec for sec and the horizontal component. An ink receiving layer thickness of 35 μm was obtained. Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Example 5> The alumina hydrate used in Example 1 was dispersed in ion-exchanged water, and polyvinyl alcohol Kuraray PVA 117) and gelatin were added as binders. The binder mixing ratio was 9: 1 by weight ratio of polyvinyl alcohol and gelatin. A coating solution was prepared by using gelatin having a weight average molecular weight of 120,000, a pH of 5.8, and an isoionic point of 6.8.

The weight of the hydrated alumina / the total weight of the binder was 13/1. This coating solution was applied to a 110 μm polyimide film (DuPont: Kapton).
The coating method was a kiss coating method at a temperature of 150 ° C., a vertical component of 2.4 m / sec, a horizontal component of 3.5 m / sec, and a coating speed of 10 m / min. The thickness of the ink receiving layer is 3
It was 5 μm.

The drying conditions are shown in Table-1 and the evaluation results are shown in Table-2. <Example 6> A coating solution was prepared using the alumina hydrate and the binder used in Example 5. Mixing ratio of binder is polyvinyl alcohol weight / gelatin weight = 9
/ 1, weight of alumina hydrate / total weight of binder = 10
/ 1.

A white polyester film (Lumirror X-21, manufactured by Toray Industries, Inc.) having a thickness of 120 μm was used as a material.

The coating method used was a gravure roll method.
Drying was performed at a temperature of 110 ° C., a vertical component of 2.3 m / sec, and a horizontal component of 3.4 m / sec. Coating speed is 8m /
It was set to min. The thickness of the ink receiving layer was 32 μm.

Table 1 shows the drying conditions and Table 2 shows the evaluation results. <Example 7> Colloidal silica (Adelite CT-100 manufactured by Asahi Denka Co., Ltd.) was used as a pigment. A coating solution was prepared with a specific surface area of 221.1 m ² / g as a catalog value, the polyvinyl alcohol used in Example 1 as a binder, and a pigment weight / binder weight of 7/1. This coating liquid was coated on art paper (size degree: 250 seconds or more) which was calendered at a basis weight of 157 g / m ² .

The coating was carried out at a speed of 15 m / min by the gravure code method, and the wind velocity of the dry gas was 140 ° C. in the vertical direction.
0 m / sec, 3.1 m / sec in the horizontal direction,
An ink receiving layer having a thickness of 32 μm was obtained.

Table 1 shows the drying conditions and Table 2 shows the evaluation results. <Example 8> The coating liquid used in Example 7 was applied to the substrate used in Example 6. The coating method is a gravure roll method, the temperature is 130 ° C., the air velocity of the gas during drying is 1.9 m / sec in the vertical direction to the coated surface, and 2.9 m in the horizontal direction.
/ Sec. At a coating speed of 15 m / min, the thickness of the ink receiving layer was 36 μm.

Table 1 shows the drying conditions and Table 2 shows the evaluation results. <Example 9> According to the method for producing an alumina hydrate shown in Example 1, the aging condition was 100 ° C for 8 hours in an oven to obtain an alumina hydrate.

The specific surface area of this hydrate is 120 m ² / g,
The pore volume was 0.441. This pigment was dispersed in ion-exchanged water in the same manner as in Example 1. Polyvinylpyrrolidone (K-90, manufactured by GAF) was used as a binder, the binder was added so that the weight of the pigment / the weight of the binder = 5/1, and a coating solution was obtained after the dispersion treatment.

The coating liquid was applied to the substrate using the white PET film used in Example 6. The coating method was a gravure roll coating method at 12 m / min. Drying was performed at a temperature of 130 ° C., a wind speed of 1.5 m / sec in the vertical direction, and 2.5 m / sec in the horizontal direction.

The thickness of the obtained ink receiving layer was 36 μm.

Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Example 10> The pigment used in Example 9 was used. Binder is polyethylene oxide (Sumitomo Seika PEO Co., Ltd.)
-8) was used to prepare a coating solution such that the pigment weight / binder weight = 8/1.

The coating method is a gravure coating method of 12 m.
/ Min.

The drying conditions were the same as in Example 9, but the thickness of the ink receiving layer was 36 μm.

Table 1 shows the drying conditions, and Table 2 shows the evaluation results. <Comparative Example 3> The drying temperature was set to 160 under the drying conditions of Example 5.
The same operation was performed except that the temperature was changed to 0 ° C. to obtain 34 μm of an ink receiving layer.

The drying conditions are shown in Table-1 and the evaluation results are shown in Table-2. [Measurement of wind speed] Below 120 ° C, electronic anemometer SK-2
7V: Sato measuring instrument Co., Ltd., and above 120 ° C., electronic anemometer SK-57AD: Sato measuring instrument Co., Ltd. were used. (Evaluation Items) [Film State of Ink Receiving Layer] It was evaluated visually. The case where a smooth surface was obtained was good, and the case where cracks and coating defects occurred was x. [Printing characteristics] 1 at a nozzle interval of 16 lines per 1 mm
Inkjets with 28 nozzles are used for Y, M, C,
Ink jet recording was performed with the following inks using a bubble jet printer equipped with four colors of Bk, and ink absorbency and beading were evaluated.

(A) Ink absorbency The dry state of the ink on the surface of the recording medium was examined by touching the recording portion with a finger immediately after solid printing of Y, M, C and Bk inks having the following compositions in a single color or multiple colors. . The ink amount in monochromatic printing was set to 100%. When the ink amount was 300%, the ink did not adhere to the finger, ⊚, when the ink amount was 200%, the ink did not adhere to the finger, ◯, and when the ink amount was 100%, the ink did not adhere to the finger, Δ.

(B) Beading The surface beading of the recording medium after solid printing of Y, M, C and k inks of the following composition in single color or multi-color was visually evaluated.

The ink amount in monochromatic printing was set to 100%.
If the ink amount does not occur at 300%, ◎, ink amount 2
If it did not occur at 00%, it was evaluated as ◯, if it occurred, it was evaluated as x, and if it was frequently generated, it was evaluated as xx. [Ink composition] -Ink dye 5 parts-Ethylene glycol 10 parts-Polyethylene glycol 10 parts-Water 75 parts Ink dye Y: C.I. I. Direct Yellow 86 M: C.I. I. Acid Red 35 C: C.I. I. Direct Blue 199 Bk: C.I. I. Hood black 2

[0102]

[Table 1]

[0103]

[Table 2]

[0104]

As described above, according to the present invention, (1) Drying temperature An image without beading can be obtained by an ink jet recording method by a manufacturing method in which the air velocity of gas during drying is controlled within a specific range. .

(2) An ink receiving layer free from coating defects can be obtained by controlling the air flow rate during drying within a specific range.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a recording medium obtained by a manufacturing method of the present invention.

FIG. 2 is a conceptual diagram showing a flow of a drying gas.

[Explanation of symbols]

 1 substrate 2 coating layer 3 dry gas outlet 4 vertical gas flow 5 horizontal gas flow

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Tomioka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (13)

[Claims] 1. A gas used for drying a coating liquid in a method for producing a recording medium which forms an ink receiving layer by coating a substrate with a coating liquid containing a pigment and a water-soluble binder and drying the coating liquid. And a wind velocity of 2.5 m / sec or less as a vertical component with respect to the coated surface and 4.0 m / sec or less as a horizontal component with respect to the coated surface. 2. The method for manufacturing a recording medium according to claim 1, wherein the temperature of the gas is in the range of 70 to 150 ° C. 3. The method for producing a recording medium according to claim 1, wherein the substrate is a substrate that does not absorb liquid. 4. The substrate has a Steckigt sizing degree of 10.
The method for producing a recording medium according to claim 1, wherein the recording medium is a paper of 0 second or more. 5. The method for producing a recording medium according to claim 1, wherein the pigment contains a metal oxide. 6. The method for manufacturing a recording medium according to claim 1, wherein the pigment is a hydrated alumina. 7. A gas used for drying a coating liquid in a method for producing a recording medium which forms an ink receiving layer by coating a substrate with a coating liquid containing a pigment and a water-soluble binder and drying the coating liquid. Recorded by a method for producing a recording medium having a drying step in which the wind velocity is 2.5 m / sec or less in the vertical component and the horizontal component is 4.0 m / sec or less in the horizontal flow coating surface. Medium. 8. The recording medium according to claim 7, wherein the temperature of the gas is in the range of 70 to 150 ° C. 9. The recording medium according to claim 7, wherein the substrate is a substrate that does not absorb liquid. 10. The substrate has a Steckigt sizing degree of 1.
The recording medium according to any one of claims 7 to 8, which is a paper of 00 seconds or more. 11. The recording medium according to claim 7, wherein the pigment contains a metal oxide. 12. The recording medium according to claim 7, wherein the pigment is a hydrated alumina. 13. An image forming method in which the recording medium is used as a recording medium, in which an ink is ejected from fine pores to be applied to the recording medium as small droplets for printing. Method.