JPH10175365A - Ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the high glossiness and the quick drying properties and good physical properties of a film after printing to be compatible each other when the ink jet recording is carried out by using an aqueous ink on an ink jet recording paper with an ink absorbent layer constituted of a space structure on a low-water-absorbent substrate. SOLUTION: Recording is carried out by using water-soluble inks of colors of at least yellow, magenta and cyanogen on a recording paper with an ink absorption layer on a non-water-absorbent substrate in a recording method. In that case, a recording paper is provided with space layers containing a hydrophilic binder and secondary fine particles of average particle diameter of 30-200nm, and the space volume of the space layers is three times or more the volume of a high boiling point organic solvent contained in the ink when the ink discharge amount is maximum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet recording method for recording using an aqueous ink, and more particularly to a method for recording a high-quality color image with high glossiness and high quality without unevenness, and immediately after recording. The present invention relates to an ink jet recording method with improved handleability.

[0002]

2. Description of the Related Art Ink-jet recording is a method in which fine droplets of ink are caused to fly according to various operating principles and adhere to a recording sheet such as paper to record images and characters. It has advantages such as easy noise and multicoloring. With regard to nozzle clogging and maintenance, which has been a problem in the past, improvements have been made in both ink and equipment, and are now rapidly spreading in various fields such as various printers, facsimile machines, and computer terminals. .

The details are described, for example, in the trend of ink jet recording technology (Koichi Nakamura, edited by Nippon Kagaku Kogyo Co., Ltd., March 31, 1995).

The recording paper used in this ink jet recording method has a high density of print dots, a bright and vivid color tone, and the ink absorbs quickly so that even if the print dots overlap, the ink may flow out. It is generally required that the ink does not bleed, that the diffusion of print dots in the horizontal direction is not unnecessarily large, and that the periphery is smooth and not blurred.

[0005] By the way, many attempts have been made in recent years to bring the image quality obtained by color ink jet recording closer to that of photographs.

This is broadly divided into characteristics relating to the ink absorbing layer, characteristics relating to the improvement of the image quality caused by dots formed on the recording paper, and characteristics relating to the support.

Attempts to improve the ink absorbing layer include:
Improve the print density by increasing the transparency of the ink absorbing layer,
It is to improve the glossiness by increasing the smoothness of the ink surface, or to secure the maximum ink absorption capacity enough to prevent the ink from overflowing in the highest density range. I have.

On the other hand, the greatest point of image quality improvement due to dots is to prevent individual dots from being visually identified. For this reason, it is necessary to reduce the size of ink droplets, or in particular, to highlight them. The point is to use a low-concentration ink as the dye concentration in order to make it difficult to identify dots in a portion, and various improvement techniques have been conventionally proposed to improve this point.

[0009] In addition, the ink penetrates into the base material of plain paper, high-quality paper, ordinary art paper, or cast-coated paper having relatively large water absorption, as the recording paper, because the ink permeates relatively easily. Only after the recording, wrinkles occur after recording, and the print quality is greatly reduced. In addition, since the ink penetrates into the paper fiber or the highly opaque white pigment-containing coat layer, there is a disadvantage that the maximum density is hardly obtained and a clear image is hardly obtained.

Furthermore, the roundness of the dots is disturbed by the presence of paper fibers and relatively large-sized white pigments, which also contributes to the deterioration of image quality during ink jet recording.

In view of the above, in order to obtain a high-quality image such as a photograph as an ink jet recording paper, it is difficult for water-based ink to penetrate, for example, a photographic support, particularly a photographic paper coated on both sides with a polyolefin. Recording paper having an ink-absorbing layer coated on a support (for example, IBM Te
mechanical Disclosure Bullet
ein (Vol. 21, N0.6, 1978, 250
2), U.S. Pat. No. 3,889,270,
No. 179032, No. 7-179025, No. 7-327
No. 23 and No. 8-1744992) and recording paper in which an ink-absorbing layer is coated on a white plastic film (for example, JP-A-61-135).
783) and the like have been preferably used.

In order to achieve the above-mentioned image quality comparable to that of photographs, it is particularly preferable to provide an ink-absorbing layer having relatively high transparency on a support having low ink-absorbing property. If the surface of the layer is matte and gloss is reduced, or if the ink absorbing layer itself has a rather large microstructure, the opacity of the ink absorbing layer will increase in addition to the decrease in gloss. Normal image quality is often difficult to achieve.

Although a large number of ink absorbing layers provided on a support have been conventionally known, they are roughly classified into two types.

One of them is a swellable ink-absorbing layer, which is mainly composed of a hydrophilic binder. In this method, ink droplets are temporarily held mainly by a swelling action of a hydrophilic binder, and after printing, water and high-boiling organic solvents contained in the ink are gradually evaporated.

The advantage of the swellable recording paper provided with this ink absorbing layer on a support is that after the ink solvent (water and high boiling point organic solvent) is completely evaporated, very high gloss and high maximum density can be obtained. Is that On the other hand, this swelling type recording paper has a problem that the ink absorption speed is slower than that of a gap type recording paper described later, and the image quality is easily deteriorated by causing beading or the like in a high ink area. Since the evaporation of the organic solvent is extremely slow, there is a problem that the hydrophilic binder is left in a swollen and wet state for a long time after printing for a while. Specifically, the printing surface cannot be strongly rubbed or paper cannot be overlapped for several hours after printing, and in some cases for several days.

As another type of ink absorbing layer different from the swelling type, there is a gap type recording paper in which the ink absorbing layer has a gap structure. The recording paper absorbs the ink by temporarily holding the ink in the gap at the time of ink-jet recording. The ink absorption speed is faster than that of the swelling type, and the image quality is less deteriorated in the high ink region.

In addition, if this type of ink-absorbing layer has a sufficient void volume with respect to the amount of ink, at least the surface is apparently dry immediately after printing, even if an organic solvent remains in the void structure. , And it is possible to touch the surface or overlap prints.

As this kind of ink-absorbing layer, fine particles having a low refractive index (especially a refractive index of about 1.6 or less are preferable) and a small particle diameter (particularly, a refractive index of about 1.6 or less) are preferred because a relatively transparent layer is formed. (Preferably 200 nm or less is preferable), and silica fine particles satisfying such conditions are particularly preferable.

As a conventional technique using such fine particle silica for ink jet recording paper, for example, Japanese Patent Publication No.
No. 6552 discloses a method of secondarily aggregating fine particle silica obtained by a gas phase method having a primary particle size of 10 to 30 nm to form an ink having a surface area of 80 to 200 m ² / g by a BET method. A recording paper having a layer is described.

The above-mentioned JP-A-8-174992 discloses that a polyolefin-coated paper support has an average particle size of 10 nm.
An ink jet recording paper which uses the following inorganic fine particles and a hydrophilic binder to obtain high glossiness is described.

However, in the case of an ink-absorbing layer having a void structure, the glossiness of the surface and the physical strength of the surface after printing tend to be inconsistent.

That is, when the void layer is viewed microscopically,
If the size of the fine particles contained therein or the microscopic void structure exceeds 200 μm, the strength of the surface after printing is good, and the problem that the ink is transferred even when touching the surface or overlapping paper or the like hardly occurs. However, the gloss tends to be extremely reduced.

When the size of the fine particles and the microscopic void structure are reduced to 200 nm or less, the gloss gradually increases, but the softness of the surface after printing increases, and ink transfer occurs when samples are overlapped. The traces tend to remain when they start to partially occur or when paper is overlaid on the ink absorbing layer surface side and written with a pencil or the like from above. In particular, when the void structure becomes 100 nm or less, this problem becomes more serious.

Although the softness of the surface immediately after printing is far better than the surface condition of the swellable ink-absorbing layer, it is at a level where improvement is desired.

The cause of such a problem relating to the strength of the film after printing is moisture and a high-boiling organic solvent, but the moisture itself remains in the void layer for a relatively short time. Although such a problem is unlikely to be a serious problem, evaporation of the high-boiling organic solvent generally requires several days at room temperature, so that the handling property during this period is easily limited.

This problem tends to be more pronounced when the print is stored in a high-humidity state after printing, because an excessive amount of water is maintained in the film. This problem is most likely to occur in a portion where the maximum amount of ink has been ejected.

The reason why this problem is likely to occur when the void structure is set to 200 nm or less is not clear, but one of the reasons is that the irregularities on the surface of the ink absorbing layer become small, and the contact with paper or the like to be overlaid. It is presumed that the structure of the film was more easily broken by an externally applied force due to the increase in the area and the finer void structure.

In Japanese Patent Application Laid-Open No. 8-1744992 and Japanese Patent Publication No. 3-56552, although the recording paper using such fine particle silica has relatively high ink absorbency and glossiness, the above-mentioned problems can be solved. No solution has been given.

[0029]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an ink-absorbing layer having a void structure on a low water-absorbing support. An object of the present invention is to provide an ink jet recording method that achieves both high glossiness, rapid drying of a film after printing, and good physical characteristics when performing ink jet recording on an ink jet recording paper having an aqueous ink. .

[0030]

An object of the present invention is to record on a recording paper having an ink-absorbing layer on a non-water-absorbing support with at least a water-soluble ink of yellow, magenta and cyan. In the ink-jet recording method, the recording paper may contain a hydrophilic binder and 30 to 2
An ink jet recording paper having a void layer containing secondary fine particles having an average particle diameter of 00 nm, wherein the void volume of the void layer is the volume of the high boiling organic solvent contained in the ink when the ink ejection amount is the maximum. This is achieved by an ink jet recording method characterized by being at least three times as large as

Hereinafter, the present invention will be described in detail.

As the non-water-absorbing support used for the recording paper of the present invention, a plastic film or a paper support having both surfaces coated with polyolefin is preferably used.

As the plastic film support, for example, polyethylene, polypropylene, polystyrene,
Plastic film supports such as polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, polyvinyl chloride, polyimide, polycarbonate, cellophane and the like are preferred.

These plastic films can be appropriately selected from transparent, translucent and opaque ones depending on the application.

When a white film is used, a support obtained by incorporating a small amount of a white pigment such as barium sulfate, titanium oxide or zinc oxide into a plastic film support may be used as it is, or a transparent film support may be used. A support provided with a layer having a white pigment (titanium oxide, barium sulfate, etc.) on the back side of the body or on the side near the support on the ink absorbing layer side may be used.

The paper support coated on both sides with polyolefin is preferably a paper support coated on both sides with polyethylene, which is conventionally used for color printing paper. In this case, the polyethylene resin layer on the ink absorbing layer side contains anatase-type or rutile-type titanium oxide in an amount of 3 to 20% by weight based on the polyethylene to improve the opacity and whiteness of the support, or It is preferable because the sharpness of the obtained image is not reduced.

In the present invention, from the viewpoint of obtaining a high-quality color image, a white film support or a paper support having both surfaces coated with a polyolefin such as polyethylene is preferred. Most preferred is a paper support coated on both sides.

Hereinafter, a paper support coated on both sides with polyethylene, which is particularly preferably used, will be described.

The base paper used for the paper support is made of wood pulp as a main raw material, and if necessary, is made of synthetic pulp such as polypropylene or synthetic fiber such as nylon or polyester in addition to wood pulp. As wood pulp, LBKP, LBSP, NBKP, NBSP, LD
Any of P, NDP, LUKP, and NUKP can be used, but LBKP, NBSP, and LBS containing a large amount of short fibers
It is preferable to use more P, NDP, and LDP.
However, the ratio of LBSP and / or LDP is 10% by weight.
At least 70% by weight is preferred.

As the pulp, a chemical pulp containing less impurities (sulfate pulp or sulfite pulp) is preferably used, and pulp having improved whiteness by a bleaching treatment is also useful.

In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, Water retention agents such as polyethylene glycols, dispersants, and softening agents such as quaternary ammonium can be appropriately added.

The freeness of the pulp used for papermaking is preferably 200 to 500 cc according to the specification of CSF, and the fiber length after beating is calculated based on 24 mesh residual weight% specified in JIS-P-8207 and 42 mesh calculated. 30% by weight
To 70% is preferable. The weight percentage of the remaining 4 mesh
Is preferably 20% by weight or less.

The basis weight of the base paper is preferably from 60 to 250 g, particularly preferably from 90 to 200 g. Base paper thickness is 5
It is preferably from 0 to 250 μm.

The base paper may be calendered at the papermaking stage or after the papermaking to provide high smoothness. The base paper density is generally 0.7 to 1.2 g / m ² (JIS-P-8118). Further, the rigidity of the base paper is preferably from 20 to 200 g under the conditions specified in JIS-P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, the same sizing agents as those which can be added to the base paper can be used.

The pH of the base paper is preferably 5 to 9 when measured by the hot water extraction method specified in JIS-P-8113. The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene ( LDPE) and / or high-density polyethylene (HDPE), but other LLDPE, polypropylene, etc. can also be used partially.

In particular, the polyethylene layer on the ink receiving layer side is preferably a layer obtained by adding rutile or anatase type titanium oxide to polyethylene to improve opacity and whiteness as widely used in photographic printing paper. The content of titanium oxide is approximately 3 to 20% by weight based on polyethylene,
Preferably it is 5 to 15% by weight.

The polyethylene-coated paper may be used as a glossy paper, or may be subjected to a so-called embossing process when the polyethylene is melt-extruded onto the base paper surface to carry out a coating process. Those having a surface can also be used in the present invention.

The amount of polyethylene used on the front and back of the base paper is selected so as to optimize the curl in low and high humidity after the ink receiving layer and the back layer are provided. Is in the range of 20 to 40 μm, and the back layer side is in the range of 10 to 30 μm.

Further, the polyethylene-coated paper support preferably has the following characteristics.

Tensile strength: JIS-P-8113
It is preferable that the strength in the vertical direction is 2 to 30 kg and the horizontal direction is 1 to 20 kg at the strength defined by

Tear strength: JIS-P-8116
It is preferable that the vertical direction is 10 to 300 g and the horizontal direction is 20 to 400 g.

Clark stiffness: 20 to 400 g / 10
0 is preferred.

Compression elastic modulus ≧ 10 ³ kgf / cm ² Surface smoothness: A Beck smoothness specified in JIS-P-8119 of 500 seconds or more, particularly 1000 seconds or more is preferable as a glossy surface. It may be less than this.

Surface roughness: From a cross-sectional curve measured by a method specified in JIS-B-0610, a filter waviness curve derived under a condition of a cut-off value of 0.8 mm is defined as:
When the maximum undulation is measured with a reference tone of 2.5 mm, the maximum undulation at 100 arbitrary measurement points is within 5 μm or more, and the 10-point average roughness is within 4 μm. Preferably it is.

Surface gloss: 30% or more, preferably 70% or more, particularly preferably 90% or more when measured at an angle of 60 degrees by the method specified in JISZ-8741.

Surface whiteness: measured by the method described in JIS-Z-8722, and expressed according to JIS-Z-8729,

[0058]

[Outside 1]

Opacity: 50% or more, particularly 90%, as measured by the method specified in JIS-P-8138
Above, most preferably 94% or more.

The thickness of the polyolefin layer covering the paper support is 15 to 50 μm, preferably 20 to 40 μm. The polyolefin layers on the front and back sides of the paper are determined by appropriately optimizing according to the concept generally used for a photographic printing paper support in consideration of the fact that the balance of the curl after applying the ink absorbency is optimized.

The thickness of the support is 100 to 300 μm,
Preferably it is 130 to 250 μm.

Prior to the application of the ink receiving layer, it is preferable to subject the support to a corona discharge treatment or a subbing treatment for the purpose of increasing the adhesive strength between the various supports and the ink image receiving layer.

In the present invention, a hydrophilic binder and secondary fine particles having an average particle diameter of 30 to 200 nm are contained in the ink absorbing layer on a support.

When a hydrophilic binder and primary particles having an average particle size of 30 to 200 nm are used on a support, no voids are formed inside the particles, and the required amount of voids is secured. In this case, the dry film thickness is remarkably increased, and the film brittleness described later is likely to be deteriorated.

When secondary fine particles having an average particle diameter exceeding 200 nm are used, the glossiness of the void layer is reduced,
Clear images cannot be obtained.

On the other hand, 2 having an average particle size of less than 30 nm
The use of the secondary fine particles tends to reduce the handleability and stability of the primary particles themselves, or make it difficult to form a stable secondary aggregate.

Here, the secondary fine particles are formed by aggregating the primary particles having a particle diameter of usually 1/5 to 1/20 of the secondary fine particles. It is preferable to aggregate primary particles of 3 to 15 nm.

The formation of the aggregates of the secondary fine particles may be carried out at any stage during the production of the recording paper. For example, the primary particles may be secondary aggregated. May be mixed with a hydrophilic binder and coated on a support, or a dispersion of primary particles may be mixed with an aqueous solution of a hydrophilic binder to form secondary particles when preparing a coating solution. Alternatively, a hydrophilic binder dispersed in the form of primary particles may be coated on a support, and secondary particles may be formed by a drying process or a heat treatment after the drying.

In the present invention, the average particle size of the secondary fine particles refers to the average particle size of the secondary fine particles in the void layer formed on the support. The average particle size of such secondary fine particles can be obtained as a simple average value (number average) by observing the cross section and surface of the void layer with an electron microscope, obtaining the particle size of 100 arbitrary secondary fine particles, and calculating the particle size. .

Here, the particle size of each secondary fine particle can be obtained as a diameter when the particle is observed with an electron microscope, the area of the projected image is measured, and a circle equal to the area is assumed.

The fine particles formed by secondary aggregation that can be used in the present invention include inorganic fine particles such as barium sulfate, calcium carbonate, zinc oxide, synthetic hectorite, and silica, and silica is particularly preferable.

The silica fine particles tend to aggregate themselves due to hydrogen bonding due to silanol groups on the surface. In particular, when aggregation is performed in the presence of a hydrophilic binder as in the present invention, relatively loose aggregation (soft aggregation) Are formed and a high porosity is achieved.

The silica fine particles are roughly classified into a dry method and a wet method according to the production method. As the dry-process fine-particle silica, a method of vapor-phase hydrolysis of silicon halide at a high temperature, and a method of heating and reducing and evaporating silica sand and coke in an electric furnace by an arc method to air-oxidize the same are known. In addition, the wet process silica is obtained by generating active silica by acid decomposition of a silicate and then polymerizing it appropriately to cause aggregation and precipitation.

In the recording paper of the present invention, fumed silica is most preferred from the viewpoint that the film has good film-forming properties, that is, it has no cracks during coating and drying and has good film-forming properties.

The above-mentioned silica also includes alumina-modified silica whose surface is partially treated with alumina.

In addition to the above-mentioned preferably used fumed silica, wet-process silica such as colloidal silica having an average particle diameter of 3 to 200 nm, calcium carbonate and the like can be used in combination. It is good to contain 20% by weight or more, preferably 30% by weight or more of the fine particles.

In the present invention, primary fine particles having an average particle diameter of 15 nm or less are preferred, and primary fine particles of 10 nm or less are most preferred from the viewpoint of glossiness and porosity.

The primary particles are agglomerated for 30 to 200 n
There are various methods for forming secondary fine particles having an average particle size of m. For example, a method of changing the pH of a uniform dispersion of primary particles or adding inorganic ions to cause aggregation of particles, or adding an aqueous solution of a hydrophilic binder that can form weak bonds such as hydrogen bonds with fine particles to cause aggregation. For example, there is a method of once forming a uniform coating of primary particles, and then applying or impregnating a coagulation promoter, causing coagulation by heat treatment, or a method combining these methods.

As described above, the secondary aggregated particles can be formed before or after mixing with the hydrophilic binder, at the time of coating and drying, or after drying by selecting an optimum method.

In the recording paper of the present invention, the hydrophilic binder used in combination with the fine particles includes polyvinyl alcohol and its derivatives, polyalkylene oxide, polyvinylpyrrolidone, gelatin, hydroxylethylcellulose, carboxymethylcellulose, pullulan, casein, and dextran. However, it is preferable to use a hydrophilic binder having a low swelling property or low solubility in water with a high boiling point organic solvent or water contained in the ink from the viewpoint of the film strength immediately after printing.

In the present invention, polyvinyl alcohol is particularly preferred. Among them, polyvinyl alcohol having an average degree of polymerization of 1,000 or more, most preferably 2,000 or more. Further, the saponification degree of the preferable polyvinyl alcohol is 70 to 100%, particularly preferably 80 to 100%.

The ratio of the fine particles to the hydrophilic binder for forming the void layer of the recording paper of the present invention depends on the type of the hydrophilic binder, the type and the particle size of the fine particles, and the magnitude of the interaction between the hydrophilic binder and the inorganic fine particles. In general, the fine particles are in a weight ratio of 4 to 4 with respect to the hydrophilic binder.
It is 10.

In particular, a ratio of 3 to the high boiling organic solvent in the ink
When the amount of ink exceeds 0% by volume or the maximum discharge amount of ink exceeds 25 ml per 1 m ^{2 of} recording paper, the ratio of inorganic fine particles to hydrophilic binder is 5 to 5 by weight.
10 is preferred.

The addition of a hardener capable of crosslinking with the hydrophilic binder to the void layer of the recording paper improves the film forming properties of the void layer, the water resistance of the film, and the printing which is the object of the present invention. This is preferable in that the strength of the subsequent film is improved. Examples of such a hardener include an organic hardener containing an epoxy group, an ethyleneimino group, an active vinyl group, and the like, and an inorganic hardener such as chrome alum, boric acid, or borax.

When the hydrophilic binder is polyvinyl alcohol, an epoxy hardener having at least two epoxy groups in the molecule, boric acid or borax is particularly preferred. The amount of the hardener added is 1 g of the above hydrophilic binder.
Per 1 to 200 mg, preferably 2 to 100 mg.

Various additives can be contained in any layer on the ink receiving layer side of the ink jet recording paper of the present invention, if necessary.

For example, JP-A-57-74193,
UV absorbers described in JP-A-57-87988 and JP-A-62-261476, and JP-A-57-74192.
Nos. 57-87989, 60-72785, 61-146591, and JP-A-1-950.
No. 91, No. 3-13376, etc., antifading agents, various anionic, cationic or nonionic surfactants, JP-A-59-42993, JP-A-5-42993.
Nos. 9-52689 and 62-280069,
JP-A-61-242871 and JP-A-4-2192.
No. 66, a whitening agent, a pH adjusting agent such as sulfuric acid, phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide, and potassium carbonate; a defoaming agent; a lubricant such as diethylene glycol; And various known additives such as a thickener, an antistatic agent, and a matting agent.

In any of the constituent layers on the ink-absorbing side of the recording paper of the present invention, a water-resistant agent for an image is disclosed in
No. 4992, polycation polymer electrolyte,
No. 7-36692, polyallylamine described in JP-B-4-15744, JP-A-61-58788, JP-A-62-174184, and JP-A-61-47290. One or more alkali metal weak acid salts can be used.

In the ink jet recording paper of the present invention, the amount of the applied solid content on the ink recording surface side is approximately 5 to 40 g / m 2.
² is preferable, and 10 to 30 g / m ² is more preferable. Note that, from the viewpoint of preventing curl after forming a recorded image, it is preferable to form the recording image as thin as possible.

The porosity of the ink absorbing layer of the recording paper is preferably from 40 to 80%. If the porosity is less than 40%, the thickness of the ink-absorbing layer becomes too large to secure the required void volume, and cracks in the ink-absorbing layer and adhesion to the support are likely to cause problems. On the other hand, when the porosity exceeds 80%, the strength of the film after printing, which is an effect of the present invention, tends to be easily reduced. Preferably, the porosity is 50 to 7
The range is 0%.

The dry thickness of the void layer is mainly determined by the porosity and the void volume, but is preferably 20 to 60 μm, particularly preferably 25 to 55 μm from the viewpoint of preventing cracking of the film.

Here, the porosity is represented by the following equation from the void volume and the dry thickness of the void layer.

Porosity (%) = 100 × (Void volume (ml
/ M ² ) / dry film thickness (μm). TAPPI paper pulp test method No. 51-87 When the ink absorbing layer side of the recording paper was measured by the method described in Liquid Absorbency Test Method for Paper and Paperboard (Bristow Method), the liquid transfer amount (ml / m ² ) when the absorption time was 2 seconds. It is represented by The liquid used at this time is pure water (ion-exchanged water), but may contain less than 2% of a water-soluble dye in order to easily determine the measurement area.

On the side opposite to the ink absorbing layer side of the recording paper of the present invention, various types of backing layers are provided to prevent curling, prevent sticking when superimposed immediately after printing, and further improve ink transfer resistance. Is preferably provided.

Although the structure of the back layer varies depending on the type and thickness of the support and the structure and thickness of the ink absorbing layer, a hydrophilic binder or a hydrophobic binder is generally used. The thickness of the back layer is usually in the range of 0.1 to 10 μm.

The surface of the back layer can be roughened in order to prevent sticking to other recording paper, to improve writing properties, and to improve transportability in an ink jet recording apparatus. Known fine organic or inorganic particles having a particle size of 2 to 20 μm are preferably used for this purpose.

In the ink jet recording method of the present invention, it is necessary that the void volume of the recording paper is at least three times the amount of the high boiling organic solvent at the maximum ink ejection amount.

Here, the maximum ink ejection amount refers to the maximum ink ejection amount when recording a normal full-color image.
This is the amount that maximizes the amount of ink ejected per 1 m ^{2 of} recording paper under the conditions for recording a normal image. This is because, depending on the ink ejection conditions of the printing apparatus, the maximum ink ejection amount is when the maximum density of the ink of the specific color is formed, and the maximum ejection amount is when the color formed by two specific colors is formed. In some cases, there are various cases such as a case where the maximum discharge amount is obtained when black is formed with three colors,
In any case, in the present invention, it is necessary to make the void amount three times or more the amount of the high boiling point organic solvent at the maximum ink amount.

When the void amount is less than three times the amount of the high boiling point organic solvent at the maximum ink amount, the strength of the film after printing becomes insufficient, or when the paper is overlapped, particularly when the high humidity The dye is easily transferred when stored under conditions.

Next, the water-soluble ink used in the ink jet recording method of the present invention will be described below.

The water-soluble ink used in the present invention is usually a recording liquid comprising a water-soluble dye, a liquid medium, and other additives. As the water-soluble dye, water-soluble dyes such as direct dyes known in inkjet, acid dyes, basic dyes, reactive dyes or food dyes can be used.
Alternatively, an acid dye is preferred.

The solvent of the aqueous ink is mainly composed of water. However, in order to prevent the dye from depositing when the ink liquid dries and to prevent clogging at the nozzle tip and the ink supply path, the boiling point is usually about 120 ° C. or higher. , A high-boiling organic solvent that is liquid at room temperature is used. High boiling organic solvents are required to have a vapor pressure much lower than that of water in order to prevent solid components such as dyes from being precipitated when water evaporates and to prevent generation of coarse precipitates. Must have high miscibility.

As such high-boiling organic solvents, high-boiling organic solvents are usually used in many cases. Specific examples include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, and diethylene. Glycol monomethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, glycerin monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol,
1,2,6-hexanetriol, thiodiglycol,
Alcohols such as triethanolamine and polyethylene glycol (average molecular weight of about 300 or less) are exemplified. In addition to the above, dimethylformamide,
N-methylpyrrolidone and the like can also be used.

Among these many high boiling organic solvents,
Preferred are polyhydric alcohols such as diethylene glycol, triethanolamine and glycerin, and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monobutyl ether.

Other additives contained in the aqueous ink include, for example, a pH adjuster, a metal sequestering agent, a fungicide, a viscosity adjuster, a surface tension adjuster, a wetting agent, a surfactant, and a rust inhibitor. Is mentioned.

The aqueous ink liquid is 25 to 50 dy at 25 ° C. for the purpose of improving the wettability to the recording paper and stabilizing the ejection from the ink jet nozzle.
It preferably has a surface tension in the range of ne / cm, preferably 28-40 dyne / cm.

The viscosity of the aqueous ink is usually 2 to 8 cp at 25 ° C., preferably 2.5 to 5 cp.

The pH of the aqueous ink is usually in the range of 4-10.

In the ink-jet recording method of the present invention, when the minimum ink droplet has a capacity of 1 to 30 × 10 ⁻³ nl, a minimum dot diameter of about 20 to 60 μm is preferably obtained on recording paper. A color print printed with such a dot diameter gives a high quality image. Preferably, a droplet having a volume of 2 to 20 × 10 ⁻³ nl is ejected as a minimum droplet.

In the method in which the water-soluble ink is recorded with two types of inks, each of which has at least twice the density of magenta and cyan, the low density ink is used in the highlight part, so that the dot of the dot is not used. Although the identification becomes difficult, the present invention can be applied to the case where such a recording method is adopted.

In the ink jet recording method of the present invention, various known methods can be used as the recording method, and details thereof are described, for example, in the trend of ink jet recording technology (Koichi Nakamura, edited by Koichi Nakamura on March 31, 1995). , Japan Science Information Co., Ltd.).

In the ink jet recording method of the present invention, the method of increasing the void volume with respect to the amount of the high boiling organic solvent at the maximum ink amount by three times or more is to reduce the ratio of the high boiling organic solvent in the ink and to reduce the maximum ejected ink amount as much as possible. The optimum conditions are set and selected by appropriately combining methods such as reducing the void volume of the recording paper and increasing the film thickness as much as possible.

In the present invention, when the amount of the organic solvent remaining in the void layer after printing exceeds one third of the void volume, the film strength immediately after printing tends to decrease as described above. Inks with a high content of high boiling organic solvents (eg 40% by volume)
Ink containing the above high boiling point organic solvent),
In order to ensure that the amount of the remaining organic solvent is 1/3 or less of the void amount even at the place where the maximum ink is discharged, the void volume is much larger than the void volume required to completely absorb the ink during printing. Although it is necessary to create a capacity, in this case, it is necessary to unnecessarily increase the thickness of the ink absorbing layer, and cracks and the like are likely to occur. From this viewpoint, in the present invention, the amount of the ink solvent is preferably 35% or less by volume, particularly preferably 30% or less.

On the other hand, the lower limit of the content of the high-boiling organic solvent is determined mainly by clogging, imparting an optimum viscosity and surface tension to the ink, and is preferably 10% by volume or more, mainly from the viewpoint of preventing clogging. Is preferably contained by 15% by volume or more.

Here, the ratio of the high boiling organic solvent in the ink is as follows:
It is expressed by volume% of the high boiling organic solvent contained in the ink. For example, when the solvent having a volume of 10 ml as measured by the high boiling organic solvent alone is contained in 100 ml of the ink, 1
It is assumed to be displayed as 0%. When two or more high-boiling organic solvents are used, the ratio of each high-boiling organic solvent is added.

The most effective method for minimizing the maximum amount of ejected ink is to make the dot diameter as small as possible. As the dot diameter decreases, the number of dots per unit area increases in order to eliminate white spots in the maximum density area, but the capacity per dot decreases, and this decrease is larger than the increase in the number of dots. Therefore, the amount of ink on the recording paper usually decreases. As a result, the film thickness required for the void volume is reduced.

Therefore, since the amount of ink printed on the recording paper decreases as the dot diameter decreases, in the present invention, the maximum diameter of the dots used in the maximum density range (a single dot is printed with a single color ink). In this case, the dot area is determined and the diameter (assuming a circle equivalent thereto) is 80 μm.
Hereinafter, it is particularly preferable to set the thickness to 60 μm.

Further, the effect of the present invention is more likely to be obtained as the void volume increases, but the careless increase in the film thickness deteriorates the brittleness of the film, and it may be caused by the drying process at the time of manufacturing or low humidity. Cracks are likely to occur or the adhesiveness to the support is likely to decrease due to an external impact during handling during storage or by other paper or writing implements. In particular, cracking during production often involves a decrease in gloss and has a relatively large effect on image quality. Therefore, it is preferable to make the dry film thickness of the film as thin as possible.

As described above, the porosity of the film is 40 to 80%, preferably 50 to 70%, as described above, and the porosity is within the range of 3 to 4 times the amount of the high boiling organic solvent at the time of maximum ink discharge. Most preferably. For this purpose, the use of hardeners which crosslink the hydrophilic binder of the coating is particularly preferred.

[0120]

The present invention will be described below with reference to examples of the present invention.
The present invention is not limited to these examples.

Example 1 150 g of primary fine silica powder obtained by a gas phase method having an average particle size of about 7 nm was added to 1000 ml of pure water, and dispersed with a high-speed homogenizer to obtain a pale and clear dispersion. Next, a 2% aqueous polyvinyl alcohol solution (II) having an average degree of polymerization of 3500 and a saponification degree of 88% (0.1% by weight of surfactant-1 and ethyl acetate in this silica aqueous dispersion (I)) was used. 1250 ml) was gradually added. Then, 20 ml of a 4% borax aqueous solution was added as a hardening agent, and the mixture was dispersed with a high-speed homogenizer to obtain a white translucent coating solution (this solution was 6 times the weight ratio of silica to polyvinyl alcohol). ).

Next, a paper support (thickness: 240 μm, anatase-type titanium dioxide in a polyethylene layer on the recording surface side) was coated on both sides of a 170 g / m ² base paper with polyethylene.
Contains 3% by weight. On the back side, 0.6 g / m ² of an acrylic latex resin having a Tg of 65 ° C. as a solid content and 0.3 g / m ² of a silica having an average particle size of about 13 μm as a matting agent.
² having a back layer).

The opacity of the polyethylene-coated paper is 9
5.2%, surface gloss (75-degree specular gloss) is 90.3
%, The cutoff value obtained from the cross-sectional curve of the surface on the ink absorbing layer side measured in accordance with JIS-B-0610.
For a filter waviness curve derived under the condition of 8 mm, when the maximum filter waviness is measured with a reference length of 2.5 mm, there is one point where the maximum waviness is 6 μm or more at 100 arbitrary measurement points, and the 10-point average roughness Was 1.3 μm, and the Bekk smoothness of the surface on the ink absorbing layer side was 2100 seconds.

The coating solution of 40 ° C. obtained as described above was applied to the recording surface side of the above polyethylene-coated paper, and cooled once (20 seconds) so that the temperature of the coating film became 15 ° C. or less. . Then blow air at 20 ° C for 30 seconds at 25 ° C.
Air for 30 seconds, 35 ° C. air for 60 seconds, and 45 ° C. air for 120 seconds to dry, and further 25 ° C.
The recording paper-1 was prepared by passing through an atmosphere having a relative humidity of 50% for 30 seconds to control the humidity.

Next, in the recording sheet-1, 1
Recording paper-2 and recording paper-3 were prepared in the same manner as recording paper-1, except that the secondary particle diameter was changed to 13 nm and 20 nm.

The recording paper obtained as described above is
C. and stored at 40-60% relative humidity for 5 days.

[0127]

Embedded image

For each of the recording papers-1 to 3, the dry film thickness, the average particle size of the secondary particles, the void volume, and the glossiness were measured. The results shown in Table 1 were obtained.

The average particle size of the secondary particles can be determined by observing the surface of each recording sheet with an electron microscope and determining the average particle size of each recording sheet.
For each of the 00 particles, the projected area is determined, and the diameter of each particle is determined as the diameter when assuming a circle equal to the area. The average particle size of the secondary particles was determined.

The void volume was determined by using a Bristow tester type II (pressurized type) manufactured by Kumagai Riki Kogyo Co., Ltd., and the amount of transition in a contact time of 2 seconds was determined as the void volume.

The gloss was measured by a 75-degree specular gloss using a variable angle photometer (VGS-101DP) manufactured by Nippon Denshoku Industries Co., Ltd.

On the other hand, an ink having the following composition was prepared for inkjet recording liquid-1.

[Recording liquid-1] Yellow ink Y-1 (high-boiling-point organic solvent ratio: 19.7%) I. Direct Yellow 86 2.1 g Diethylene glycol 15.3 ml Glycerin 4.4 ml Make up to 100 ml with pure water (ion-exchanged water).

Magenta Ink M-1 (high boiling point organic solvent ratio: 21.2%) Magenta Dye-1 1.8 g below Diethylene glycol 13.1 ml Glycerin 8.1 ml Finished with pure water (ion-exchanged water) to 100 ml.

Cyan Ink C-1 (high-boiling-point organic solvent ratio: 20.3%) I. 2.8 g of direct blue 199 g 13.1 ml of diethylene glycol 7.2 ml of glycerin Make up to 100 ml with pure water (ion-exchanged water).

[0136]

Embedded image

An on-demand type ink jet recording head (nozzle diameter = 25 μm, droplet diameter = approximately 27 μm, droplet volume = approximately 10 × 10 ⁻ ) using the above-described ink liquid to discharge ink by a piezo vibrator. and ink jet recording paper -1～3 ejection density 720 dpi (discharge interval = approximately 35 [mu] m) by ejecting conditions were adjusted respectively so that the ⁶ [mu] l.). At this time, the maximum ejected ink amount was about 8.1 ml / m ² per ink color. The amount when the yellow, magenta, and cyan inks are simultaneously ejected at the maximum is 24.3 ml / m ² .

Using the above-mentioned recording paper-1 to 3 and the ink jet recording liquid, the drying property and the film strength after printing were evaluated by the following methods.

(1) Drying property The yellow, magenta,
After printing each color of cyan and cyan at the same time,
After storing at 3 ° C. and a relative humidity of 65% for 30 minutes, 80 g /
200 sheets of m2 ^high quality paper were stacked and stored for one day and night, and the ink transferability was examined based on the following criteria.

A: No transfer at all A: Slight traces of dye transfer remain but little change in the image itself C: Large transfer traces, and the surface of the image also becomes devitrified C: Paper and ink absorbing layer The adhesion was large and the paper could not be peeled off cleanly. After printing, the paper was stored under the same conditions for 24 hours, and then the paper was overlaid and the same evaluation was performed.

(2) Film strength after printing After the solid printing of three colors simultaneously under the same conditions as in the evaluation of the drying property in (1), the film was allowed to stand for 2 days, and then subjected to a scratch strength at 23 ° C. and a relative humidity of 80%. Using a testing machine (Haydon Tribogear, manufactured by Shinto Kagaku Co., Ltd.), a continuous load of 0 to 100 g was applied to a sapphire needle having a tip of 0.3 mm to test the film strength.
The strength at which the film was broken was determined as the film strength.

When the evaluation method is approximately 30 g or more, it can be said that the film has practically sufficiently high film strength.

Table 1 shows the above results.

[0144]

[Table 1]

From the results shown in Table 1, when the recording paper-3 was used, the glossiness of the secondary aggregated particles exceeded 200 nm, and the gloss was greatly reduced. have. In particular, the particle size of the secondary particles is 100 nm.
It can be seen that the following recording paper-1 has high glossiness.

On the other hand, with respect to the recording papers 1-3, in the ink jet recording of this embodiment, V / H,
That is, it has voids 4.9 to 5.1 times the amount of the high boiling point organic solvent at the time of maximum ink ejection, and has good drying properties.

From the above, it can be seen that according to the recording method of the present invention using recording paper-1 and recording paper-2, both high glossiness, good drying property, and high film strength after printing can be achieved.

Example 2 The ink jet recording liquid-1 used in Example 1 was changed to the following recording liquid-2, and the amount of droplets ejected from the head was adjusted so as to be the same as in Example 1. Recording paper 1-3
Was used to evaluate the drying property and the film strength after printing in the same manner as in Example 1, and the results shown in Table 2 were obtained.

[Recording liquid-2] Yellow ink Y-2 (high boiling point organic solvent ratio: 26.3%) I. Direct Yellow 86 2.1 g Diethylene glycol 22.3 ml Glycerin 4.0 ml Make up to 100 ml with pure water (ion-exchanged water).

Magenta Ink M-2 (High boiling point organic solvent ratio: 29.8%) Magenta Dye-1 1.8 g Diethylene glycol 22.0 ml Glycerin 7.8 ml Finished to 100 ml with pure water (ion-exchanged water).

C. Ink C-2 (high-boiling-point organic solvent ratio: 29.7%) I. 2.8 g of direct blue 199 g 24.6 ml of diethylene glycol 5.1 ml of glycerin Make up to 100 ml with pure water (ion-exchanged water).

[0152]

[Table 2]

From the results shown in Table 2, even if the amount of the ink solvent was increased and the void volume was reduced to about 3.5 to 3.6 times the high boiling organic solvent at the time of maximum ink ejection, the recording paper-1 ,
According to the recording method of the present invention using No. 2, although the film strength immediately after printing is slightly lower than that in Example 1, it is at a level which is sufficiently satisfactory for practical use.

Comparative Example-1 The ink jet recording liquid-1 used in Example 1 was changed to the following recording liquid-3, and the amount of droplets discharged from the head was adjusted to be the same as that in Example 1. , Recording paper-1 to 3
And the film strength after printing was evaluated in the same manner as in Example 1 to obtain the results shown in Table 3.

[Recording liquid-3] Yellow ink Y-3 (high-boiling-point organic solvent ratio: 36.4%) I. Direct Yellow 86 2.1 g Diethylene glycol 31.8 ml Glycerin 4.6 ml Finished to 100 ml with pure water (ion-exchanged water).

Magenta Ink M-3 (Ratio of high boiling point organic solvent: 37.8%) Magenta Dye-1 1.8 g Diethylene glycol 32.6 ml Glycerin 5.2 ml Make up to 100 ml with pure water (ion-exchanged water).

Cyan Ink C-3 (Ratio of high boiling point organic solvent: 37.2%) I. 2.8 g of direct blue 199 g 31.3 ml of diethylene glycol 5.9 ml of glycerin Make up to 100 ml with pure water (ion-exchanged water).

[0158]

[Table 3]

In this comparative example, the drying property of all of the recording papers-1 to 3 was significantly lower than that of the first and second embodiments, although the drying was performed three times or less with respect to the high boiling point organic solvent at the time of maximum ink discharge. In addition, it can be seen that the film strength after printing is at a level that may be deteriorated particularly on recording paper having a high glossiness and may cause a practical problem.

Example 3 In the recording papers 1-3 prepared in Example 1, the wet film thickness was increased by about 20% using the respective coating liquids, and the recording papers were processed in the same manner as the recording papers 1-3. -1A, 2
A and 3A were prepared.

In the same manner as in Example 1, the particle diameter of the secondary particles, the dry film thickness, the void volume and the gloss were measured.

On the other hand, ink jet recording was carried out using the ink jet recording apparatus used in Example 1 and the recording liquid used in Comparative Example 1 as the recording liquid. The strength was checked. Table 4 shows the results.

[0163]

[Table 4]

As can be seen from Table 4, when the wet film thickness at the time of coating is increased, the dry film thickness and the void volume increase almost in proportion to the wet film thickness, but the gloss tends to slightly decrease.

This is because, when viewed in detail, slight cracks were formed on the surface of the ink absorbing layer during coating and drying.

From the results shown in Table 4, even when an ink containing a high-boiling-point organic solvent at a high concentration is used, the amount of voids in the recording paper exceeds three times the amount of the high-boiling-point organic solvent when the maximum ink is ejected. , Maintain good drying properties and film strength after printing, and also achieve high gloss when using recording paper-1 and 2, in which the average particle size of secondary particles is 200 nm or less. I understand.

Comparative Example 2 In the ink jet recording apparatus used in Example 1, the ink jet recording head was configured so that the nozzle diameter was 30 μm, the droplet diameter of each ink discharged was about 32 μm, and the droplet volume was about 18 ×
The recording head was changed to a head whose discharge conditions were adjusted so as to be 10 ⁻⁶ μl (the recording liquid used in Example 3 was used). Further, the ejection density was set to 600 dpi (ejection interval ≒ 4
2 μm), and inkjet recording was performed on the recording paper-1A to 3A used in Example 3. At this time, the maximum amount of ejected ink was about 10.2 ml / m ² per ink color. The amount when the yellow, magenta and cyan inks are ejected simultaneously at the maximum is 30.6 ml / m ² .

The drying property and the film strength after printing were evaluated in the same manner as in Example 1, and the results shown in Table 5 were obtained.

[0169]

[Table 5]

Further, from the results in Table 5, it can be seen from the results that even if the recording paper and the recording liquid used in Example 3 were used, even if the ejection interval was made to correspond to this due to the increase in the droplet diameter, the overall recording paper Because the amount of voids was less than three times the amount of high-boiling organic solvent at the time of maximum ink ejection due to the increase in ejection amount,
The drying property and the film strength after printing decreased.

Example 4 In the recording papers-1 to 3 produced in the embodiment 1, the recording papers-1B to 3-3 each having a wet film thickness increased by about 40%.
B was prepared in the same manner as in recording papers 1-3.

Table 6 shows the results of the particle size, void volume, and glossiness of the secondary particles of recording paper-1B, 2B, and 3B.

Further, the ink jet recording apparatus used in Comparative Example 2 was evaluated in the same manner as in Comparative Example 2 using the recording liquid used in Comparative Example 1, and the results shown in Table 6 were obtained.

[0174]

[Table 6]

From the results shown in Table 6, the amount of voids increases as the coating film thickness further increases, but the glossiness further decreases.
However, if the recording paper is about 1B or 2B, it is at a practically acceptable level, but the gloss of 3B completely disappears and a so-called matte surface is obtained.

Further, from the results in Table 6, the drying property and the film strength after printing are lower than those in Examples 1 and 2, but are better than those in Comparative Examples 1 and 2.

Example 5 In the recording papers 1-3 prepared in Example 1, recording papers -1C, 2C, and 3C in which borax was not added as a hardener.
Was prepared.

With respect to the recording paper prepared in Example 1, except that the polyvinyl alcohol concentration of the aqueous solution (II) was changed to 4%, the recording paper-1 was prepared in the same manner as recording papers 1-3.
D, 2D and 3D were produced.

In the recording papers 1-3 prepared in Example 1, polyvinyl alcohol was used in which the average degree of polymerization was about 1700.
The recording paper-1E was prepared in the same manner as the recording paper-1 to 3 except that the saponification degree was changed to polyvinyl alcohol having a saponification degree of 88%.
2E and 3E were produced.

Further, the recording papers-1 to 1 produced in Example 1
In No. 3, after coating on a polyethylene-coated paper, air was blown at 70 to 100 ° C. without cooling during drying, and dried to prepare recording paper-1F, 2F, and 3F.

Each of the recording papers was examined for dry film thickness, void volume, and glossiness in the same manner as in Example 1. Table 7 shows the results.

On the other hand, using the recording liquid used in Example 2,
In the same manner as in Example 2, the drying property and the film strength after printing were examined. Table 7 shows the results.

[0183]

[Table 7]

From the results in Table 7, when borax was removed as a hardener (recording paper-1C to 3C), recording paper-1
Although the film strength and gloss after printing are slightly lower than those of Nos. 1 to 3, the void volume and the drying property are hardly changed.

When the amount of the polyvinyl alcohol used in the recording paper-1 was doubled and the ratio of the hydrophilic binder to the inorganic fine particles was reduced to 光 沢, the glossiness was improved, but the void volume was about 2 times. / 3, the void volume with respect to the amount of the high boiling organic solvent is three times or less, and the drying property and the strength of the film after printing are greatly reduced.

In the recording paper-1, when the polyvinyl alcohol was changed to one having a lower average degree of polymerization, the glossiness was slightly lowered, but the drying property and the film strength were almost the same as when the borax was removed. ing.

In the sample which was heated and dried without being set after cooling after coating in the production of the recording paper-1, not only the void volume was reduced and the drying property and the film strength were deteriorated, but also the gloss due to cracking was observed. Decreased.

[0188]

As described above, when the ink jet recording method of the present invention is used, a high-quality color image having high maximum density and sharpness and high gloss can be obtained. Immediately after printing, a full-color image is obtained in which the strength of the film on the surface is sufficiently strong and handleability is excellent.

Claims (7)

[Claims] 1. An ink jet recording method for recording on a recording paper having an ink-absorbing layer on a non-water-absorbing support using at least a water-soluble ink of yellow, magenta and cyan, wherein the recording paper is hydrophilic. What is claimed is: 1. An ink jet recording sheet having a void layer containing a binder and secondary fine particles having an average particle diameter of 30 to 200 nm, wherein the void volume of the void layer is a high boiling point contained in the ink when the ink discharge amount is the maximum. An ink jet recording method characterized in that the volume of the organic solvent is three times or more. 2. The ink jet recording method according to claim 1, wherein the secondary fine particles are silica. 3. The ink jet recording method according to claim 1, wherein the ratio of the secondary particles to the hydrophilic binder is 4 to 10 by weight. 4. The ink jet recording method according to claim 1, wherein the hydrophilic binder is polyvinyl alcohol. 5. The ink jet recording method according to claim 1, wherein the gap layer contains a hardener. 6. The ink-jet recording according to claim 1, wherein the amount of the high-boiling organic solvent contained in the water-soluble ink is 35% by volume or less based on the volume of the ink. Method. 7. The ink jet recording method according to claim 1, wherein the non-water-absorbing support is a paper support having both surfaces coated with polyolefin.