JP3324425B2 - Method for manufacturing ink jet recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet recording medium, and more particularly to a method for manufacturing an ink jet recording medium having excellent print density, glossiness, and water resistance after printing.

[0002]

2. Description of the Related Art An ink jet recording system is a system in which ink droplets ejected from a nozzle at a high speed are adhered to a recording material for recording, and has features such as easy full-color printing and low printing noise. . In this method, since the ink used contains a large amount of solvent, it is necessary to use a large amount of ink in order to obtain a high recording density. In addition, since the ink droplets are continuously ejected, the next droplet is ejected before the first droplet is absorbed, which is likely to cause a disadvantage that the ink droplets are fused and ink dots are joined. Therefore, the recording medium used in the ink jet recording method has a high print dot density, a bright and vivid color tone, and has a high ink absorption, and does not have ink bleeding even when the print dots overlap. Etc. are required. Recently, in response to the rapid spread of inkjet printers, in the printing field, glossy, high-print-density printed matter has been demanded for various publications, packaging, and the like. In particular, in the case of color recording, the need for a film or coated paper type is high in terms of ink acceptability such as dot shape (circular shape), dot sharpness, ink absorption, fixing speed, and ink absorption capacity. .

[0003] Since general ink-jet inks are water-soluble, they have the drawback that printed images have low moisture and water resistance. Therefore, in order to improve moisture resistance and water resistance,
It is common to incorporate a cationic resin into the paper or recording layer. For example, as disclosed in Japanese Patent Publication No. 2-035673 and the like, a pigment or a cationic resin is filled in an ink jet recording paper, and an anionic dye in the ink is fixed to thereby fix the humidity and water resistance of an image printed. It is known to improve. Further, there is a coated paper provided with a coating layer containing a pigment such as silica or alumina in order to enhance the print image quality (control of dot sharpness, etc.) and print density of the ink jet recording paper (for example:
Japanese Patent Application No. 7-260198). These coated papers are generally composed mainly of a pigment of several microns order, a cationic resin and an adhesive (binder), and the ink is absorbed by the presence of the pigment. The dye in the absorbed ink is fixed by the cationic resin, but the pigment used has a large particle size, so the transparency of the coating layer is low, and the surface is easily rough and glossy. It is difficult to obtain a recording.

For the purpose of improving glossiness and print density, the present inventors pulverize fine particles such as micron-order silica by a mechanical dispersion method to produce colloidal particles having a particle size of 500 nm or less. It has been clarified that it is possible to obtain an ink jet recording medium having high gloss and high print density by using the same (Japanese Patent Application No. 8-102494).
No.). However, since colloidal particles such as silica have an anionic property, they have no fixing power to dyes as they are, and have a disadvantage of poor moisture resistance and water resistance after printing. On the other hand, when a cationic resin is added thereto, aggregation occurs,
Transparency and surface smoothness may be significantly reduced. In addition, when a cationic resin is added, the coating liquid thickens due to agglomeration, and there is a problem that coating becomes difficult. Therefore, the present inventors have proposed a method of adsorbing a water-soluble resin on the surface of anionic colloidal pigment particles in advance and then adding a cationic resin (Japanese Patent Application No. 8-73700). In this method, the colloid particles are primary particles, that is, the specific surface area of the colloid particles is small to some extent, and the surface needs to be almost covered with the water-soluble resin. When the colloidal particles become secondary particles having a large ink absorption capacity, the specific surface area increases greatly, and it is difficult to completely cover the surface with a water-soluble resin. And the surface smoothness may be reduced.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for producing an ink jet recording medium having higher printing density, glossiness, and excellent moisture and water resistance after printing. .

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present invention has found that a dispersion containing pigment fine particles having an average particle diameter of 300 nm or less is agglomerated and thickened by a cationic resin. After that, the resulting cationic resin
The pigment aggregates are pulverized so that the average particle diameter of the aggregates is 1 μm or less, redispersed, and at least one recording layer of an ink jet recording medium is formed by using the dispersion to obtain high print density and gloss. It was found that an ink jet recording medium having excellent moisture resistance and water resistance after printing was obtained. In general, when pigment particles having a particle size on the order of microns and a cationic resin and a binder are mixed and dispersed, even if the pigment particles and the cationic resin in the dispersion aggregate, the coating obtained by coating is obtained. Although it does not particularly affect the coating layer, the use of pigment fine particles having an average particle size of 300 nm or less not only significantly reduces the transparency of the coating layer, but also makes the surface easily rough,
It is difficult to obtain a glossy surface with excellent smoothness. Particles such as amorphous silica exhibit anionic properties in water, and of course, silica colloidal particles composed of secondary particles are also anionic. The anionic silica fine particles have no fixing property to the dye in the ink, and the printed image has low moisture resistance and water resistance.
In order to improve the moisture resistance and water resistance of a printed image, it is essential to add a cationic resin or the like. However, when a cationic resin is added to an anionic pigment such as anionic silica colloidal particles, the dispersion immediately thickens and agglomerates, and even when this coating liquid is applied, a glossy and transparent recording layer is formed. Difficult to obtain.

The inventors of the present invention have conducted intensive studies and have found that, for example, a cationic resin is added to a dispersion of pigment fine particles having an average particle diameter of 300 nm or less to aggregate and thicken the pigment particles and the cationic resin. Thereafter, the formed cationic resin-pigment aggregate particles are pulverized and dispersed, and the average particle size of the aggregate particles is 1
It was found that a recording layer having gloss and transparency could be obtained by forming at least one recording layer of an ink jet recording medium using the dispersion liquid so as to have a thickness of not more than μm.

The method for producing an ink jet recording medium of the present invention comprises the steps of: silica, carion, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, pseudoboehmite, calcium carbonate, satin white, aluminum silicate A dispersion of at least one pigment particle selected from smectite, zeolite, magnesium silicate, magnesium carbonate, magnesium oxide, and diatomaceous earth in the form of aggregate particles of primary particles having an average primary particle diameter of 3 to 40 nm. , A cationic resin was mixed to prepare a thickened / agglomerated mixed solution, and the mixed solution was subjected to a pulverization / dispersion treatment, and aggregate particles of the cationic resin and the pigment particles in the mixed solution were obtained. The powder is pulverized until the average particle diameter becomes 1 μm or less, and the powder The present invention is characterized in that an ink jet recording layer containing pulverized particles of an aggregate of a thion resin and pigment particles is formed.

In the method for producing an ink jet recording medium of the present invention, the pigment particles before mixing have an average particle size of 30.
It is preferably 0 nm or less. In the method for producing an ink jet recording medium of the present invention, the ink jet recording layer preferably further contains a binder. In the method for producing an ink jet recording medium of the present invention, it is preferable that the pigment particles are selected from amorphous silica particles, zeolite particles, and calcium carbonate particles. In the method for producing an ink jet recording medium of the present invention, the pigment particles 100
It is preferable that 1 to 30 parts by mass of the cationic resin is mixed with respect to parts by mass.

In the method for producing an ink jet recording medium of the present invention, when forming the ink jet recording layer, a coating solution containing pulverized particles of the aggregate of the pigment particles and the cationic resin is applied onto a molding surface. It is preferable to form a film and transfer the film onto at least one surface of the sheet-like support. In the method for producing an ink jet recording medium of the present invention, the ink jet recording layer containing the pulverized particles of the aggregate of the pigment particles and the cationic resin may be formed on at least one surface of the sheet-like support in advance. It may be transferred and formed on the ink jet recording layer.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION After a dispersion containing fine particles having an average particle size of 300 nm or less is agglomerated and thickened by a cationic resin, this is ground and redispersed so that the average particle size becomes 1 μm or less. When at least one recording layer of an ink jet recording medium is formed by using the dispersion liquid, it is possible to obtain an ink jet recording medium having excellent glossiness, high printing density, moisture resistance and water resistance after printing.

In the ink jet recording medium of the present invention,
The support is not particularly limited, and a transparent or opaque support can be used. For example, plastic films such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, and polyester, fine paper, art paper, and coat Paper, cast coated paper, foil paper, kraft paper,
Papers such as polyethylene laminated paper, impregnated paper, vapor-deposited paper, and water-soluble paper, metal foil, and synthetic paper are appropriately used.

Next, the ink jet recording layer of the ink jet recording medium of the present invention will be described. First, the pigment fine particles of 300 nm or less will be described. Examples of fine pigment particles include silica, kaolin, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, pseudoboehmite, calcium carbonate, satin white, aluminum silicate, smectite, zeolite, and magnesium silicate. Various known and used pigments in the general coated paper field, such as magnesium carbonate, magnesium oxide, and diatomaceous earth, are used. These pigments are affected by the pH and the like and cannot be said unconditionally, but are almost anionic pigments other than alumina pigments. Among the above pigments, amorphous silica, zeolite and calcium carbonate are preferred, and amorphous silica is particularly preferred. After the pigment is dispersed in water or the like, the pigment is crushed and dispersed by a mechanical method until the average particle diameter of the pigment is 300 nm or less. It is preferable that the particles are pulverized and dispersed to 200 nm or less, more preferably 150 nm or less.

The fine particle pigment having an average particle diameter of 300 nm or less is preferably a secondary particle pigment. Constituting secondary particles 1
The average particle size of the secondary particles is preferably 3 to 40 nm.
If the primary particle size is smaller than 3 nm, the cationic resin absorbing ability may be insufficient, and if it is larger than 40 nm, the transparency of the obtained ink recording layer may be reduced. In order to obtain secondary particles having an average particle size of 300 nm or less, a commercially available pigment particle having an average particle size of several microns is applied with a strong force by mechanical means. In other words, breaking
It can be obtained by a down method (a method of subdividing a bulk raw material). As the mechanical means, an ultrasonic homogenizer,
Examples include mechanical methods such as a high-speed rotation mill, a roller mill, a container driving medium mill, a medium stirring mill, a jet mill, a sand grinder, a pressure homogenizer, and the like. All the average particle diameters referred to in the present invention are the particle diameters observed with an electron microscope (SEM and TEM) (taken with an electron microscope photograph of 10,000 to 400,000 times, measured and averaged by Martin diameter. "Particle Handbook") Asakura Shoten, p. 52, 1991). Of course, in addition to the cationic resin-pigment aggregate pulverized particles obtained by the above method, various other commercially available pigments (e.g., silica, colloidal silica, alumina, calcium carbonate, plastic pigment, and the like) can be used to obtain a recording layer. As long as the transparency and glossiness of the ink are not impaired, a small amount may be added to increase the ink absorbency.

As the cationic resin, a water-soluble or aqueous emulsion type is used. For example, polyalkylene polyamines such as polyethylene amine and polypropylene polyamine, or derivatives thereof, acrylic resins having tertiary amino groups and quaternary ammonium groups, diacrylamine, and the like are used alone or in combination. Also, a dicyandiamide-formalin polycondensate represented by dicyandiamide-cationic resin, a dicyandiamide-diethylenetriamine polycondensate represented by polyamine-based cation resin, epichlorohydrin / dimethylamine addition polymer, dimethyldiallylammonium chloride / SO ₂
Polycations such as copolymer, diallylamine salt / SO ₂ copolymer, dimethyldiallylammonium chloride polymer, allylamine salt polymer, dialkylaminoethyl (meth) acrylate quaternary salt polymer, and acrylamide-diallylamine salt copolymer And cationic resins. The amount of the cationic resin to be added is as follows: pigment 1
The amount is preferably adjusted in the range of 1 to 30 parts by weight, more preferably 3 to 25 parts by weight, relative to 00 parts.

The ink jet recording layer of the ink jet recording medium of the present invention contains an adhesive (binder).
Examples of the adhesive (binder) include water-soluble resins (for example, polyvinyl alcohol (hereinafter also referred to as PVA), casein, soybean protein, synthetic proteins, starch, cellulose derivatives such as carboxymethylcellulose and methylcellulose), styrene-butadiene copolymer, Methyl methacrylate-butadiene copolymer conjugated diene polymer latex, acrylic polymer latex, styrene
A known adhesive (binder) generally used for coated paper, such as a water-dispersible resin such as a vinyl copolymer latex such as a vinyl acetate copolymer, is used alone or in combination. The adhesive may be added before, during, or after the addition of the cationic resin to the fine particle dispersion, but may be added to the pigment particle dispersion before adding the cationic resin. It is preferred to add. Although the reason is not clear, it is considered that the cationic resin may be easily aggregated by the pigment particles by adsorbing the adhesive on the surface of the pigment particles and suppressing the ionicity of the pigment particles to some extent.

The weight ratio of the solid content of the pigment and the adhesive (binder) in the recording layer is adjusted in the range of 100/5 to 100/200, preferably 100/10 to 100/100. If the amount of the adhesive (binder) is large, the pores between the particles become small, and it is difficult to obtain an ink absorption rate. On the other hand, if the amount of the adhesive (binder) is small, the coating layer tends to crack. In addition, various auxiliaries such as dispersants, thickeners, antifoaming agents, coloring agents, antistatic agents, preservatives, etc. used in the production of general coated paper are appropriately dispersed before grinding, during grinding dispersion, or after grinding dispersion. Is added.

When the cationic resin is added to the pigment particle dispersion, the cationic resin and the pigment particles aggregate, and the dispersion once thickens and aggregates. This dispersion is subjected to a pulverization and dispersion treatment so that the cationic resin-pigment aggregate has an average particle size of 1 μm.
Or less, preferably 500 nm or less, more preferably 300 nm or less.
Grind to less than nm and redisperse. This pulverization and dispersion treatment can be performed by mechanical means. Examples of the mechanical means include mechanical means such as an ultrasonic homogenizer, a homomixer, a high-speed rotation mill, a roller mill, a container driving medium mill, a medium stirring mill, a jet mill, a sand grinder, and a pressure type homogenizer. In the present invention, for example, the colloidal secondary particles of the pigment are aggregated by adding a cationic resin, but the aggregating force is considered to be much weaker than the bonding force of the primary particles forming the secondary particles. It is possible to break the bond of the cationic resin-pigment aggregate by mechanical force, but it is very difficult to break the bond between the primary particles. Therefore, after adding the cationic resin, the cationic resin-
Even if the pigment aggregate is subjected to a pulverization dispersion treatment,
One wall is grinding to the average particle size of the secondary particles.
Therefore, in the redispersed state, it is considered that tertiary aggregate particles formed by bonding the secondary pigment particles and the cationic resin also exist at the same time.

[0019] Although there is no particular limitation on the coating amount of the ink-jet recording layer, preferably 1 to 100 g / m ^2, and more preferably adjusted to 5 to 70 g / m ^2. If it is small, it is difficult to obtain a uniform coating film, and if it is large, the effect is saturated, and
Cracks easily occur in the coating film. In the configuration having two or more inkjet recording layers on the support, at least one
The layer is a layer containing the cationic resin-pigment aggregate ground particles obtained by the method described above. The other recording layers also have the same basic configuration as the single-layer recording layer, and include the above-described cationic resin-pigment aggregate pulverized particles and a layer containing an adhesive, a polymer resin-containing layer used for the adhesive, and the like. Be composed. After applying the ink jet recording layer of the present invention to the molding surface to form a film, this film is transferred to one surface of the support or to another recording layer previously formed thereon to obtain a higher gloss. Is obtained.

Examples of the material used for the molding surface include cellophane having high surface smoothness, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride,
Flexible films such as plastic films such as polyester, polyethylene laminated paper, glassine paper, impregnated paper, vapor-deposited paper, metal foil, synthetic paper, etc., and highly smooth surfaces such as inorganic glass, metal, and plastic Drums and plates are appropriately used. In particular, a polymer film (polyethylene, polypropylene, polyester, or the like) or a metal drum having a highly smooth surface is preferable from the viewpoints of the manufacturing process and the suitability for separation between the molding surface and the recording layer. The molded surface is preferably smooth for the purpose of imparting gloss,
As for the surface roughness (JIS B-0601) of the molding surface, Ra is preferably 0.5 μm or less, and more preferably Ra is 0.5 μm.
It is not more than 05 μm. In addition, it is also possible to give a texture such as semi-gloss tone or matte tone by controlling the surface roughness.

The molding surface may be left untreated. However, in order to control the adhesive force between the molding surface and the recording layer to be smaller than the adhesive force between the recording layer and the support (or another recording layer), the coating surface is not coated. It is possible to apply a compound having releasability, such as silicone or fluororesin, on the surface to be used. Examples of the coating coater for the recording layer of the present invention include various known coating apparatuses such as a die coater, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, and a curtain coater, and a size press. And the like.

The ink used for recording on the ink jet recording medium of the present invention comprises a dye for forming an image and a liquid medium for dissolving or dispersing the dye as essential components. It is prepared by adding a dispersing agent, a surfactant, a viscosity adjusting agent, a specific resistance adjusting agent, a pH adjusting agent, a fungicide, a dissolution or dispersion stabilizing agent of a recording agent, and the like. Examples of the recording agent used in the ink include a direct dye, an acid dye, a basic dye, a reactive dye, an edible dye, a disperse dye, an oil dye and various pigments, and conventionally known ones are used without any particular limitation. be able to. The content of such a dye is determined depending on the type of the liquid medium component, the characteristics required for the ink, and the like, but in the case of the ink of the present invention, the composition as in the conventional ink, that is, 0.1
There is no particular problem in use at a ratio of about 20% by weight.

As the solvent of the ink used in the present invention, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol,
C1-C4 alkyl alcohols such as isopropyl alcohol, n-butyl alcohol and isobutyl alcohol; ketone or ketone alcohols such as acetone and diacetone alcohol; polyethylene glycol, polyalkylene glycols such as polypropylene glycol, ethylene glycol; Alkylene glycols having 2 to 6 alkylene groups such as propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, diethylene glycol, amides such as dimethylformamide, ethers such as tetrahydrofuran, glycerin, ethylene Polyvalent alcohols such as glycol methyl ether, diethylene glycol methyl (ethyl) ether, and triethylene glycol monomethyl ether Such as lower alkyl ethers and the like.

[0024]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto.
The ink jet recording medium obtained in the present invention has 20
A calendering treatment of kg / cm was performed. Also, "part" in the example
And "%" are solids, excluding water, unless otherwise noted.
Parts by mass and% by mass are shown. [Silica sol] Average particle size 3μ
m synthetic amorphous silica (manufactured by Nippon Silica Industry Co., Ltd., trade name:
Nipsil, HD-2, primary particles: 11 nm)
After being pulverized and dispersed by a sand grinder, the mixture was further pulverized and dispersed by a pressure homogenizer, and the pulverization and dispersion operation of the sand grinder and the pressure homogenizer was repeated until the average particle diameter of the secondary particles became 70 nm, thereby producing a 5% dispersion liquid as a trial. .

The particle size of the dispersed particles was measured by the following method. Observation was performed with a TEM (transmission electron microscope, H-300, manufactured by Hitachi, Ltd.). After diluting the dispersion to 0.5%,
The solution was dropped on a collodion film, air-dried, and used for observation.
Electron microscope magnification: Selected from 20,000 times, 50,000 times, and 100,000 times.

Example 1 100 parts of the above silica sol was mixed with polyvinyl alcohol (Kuraray Co., trade name: PVA-135H, polymerization degree: 350).
0, saponification degree: 99% or more) 30 parts, diallyldimethylammonium chloride-acrylamide copolymer (manufactured by Nitto Boseki Co., Ltd., trade name: PAS-J) as a cationic resin
-81) 10 parts were added. The resulting thickened / agglomerated mixture is subjected to pulverization and dispersion treatment with a sand grinder and a pressure homogenizer, and the cationic resin in the mixture is
The pigment aggregate particles were pulverized and dispersed until the average particle diameter became 150 nm to prepare a 4% dispersion. This dispersion was laminated with commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g / m ² ) so that the coating amount was 20 g / m ² (by the extrusion lamination method). A 15 μm polyethylene laminated on the surface of a coated paper (hereinafter, also simply referred to as a laminated coated paper) was applied and dried to form an ink jet recording layer, thereby producing an ink jet recording body of the present invention.

Example 2 30 parts of polyvinyl alcohol (Kuraray Co., trade name: PVA-135H) and 100 parts of diallyldimethylammonium chloride-acrylamide copolymer (Nitto Boseki Co., Ltd., trade name: P
AS-J-81). Subsequently, the obtained thickened / agglomerated mixture was subjected to a pulverization / dispersion treatment using a sand grinder and a pressure homogenizer, and the average particle size of the cationic resin-pigment aggregate particles in the mixture was 750 nm.
To obtain a 4% dispersion. A commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g) is coated with this dispersion so that the coating amount is 20 g / m ^2.
/ M ² ) (15 μm polyethylene laminated on the coated paper surface by extrusion lamination, hereinafter also referred to as laminated coated paper) and dried to form an ink jet recording layer,
An ink jet recording medium of the present invention was manufactured.

Example 3 An ink jet recording medium was manufactured in the same manner as in Example 1, except that the cationic resin was changed to diallyldimethylammonium chloride (trade name: PAS-H-10L, manufactured by Nitto Boseki Co., Ltd.). . Example 4 Using the same coating liquid as in Example 1, the coating amount was 20 g / m ^2.
PET film (Toray, Lumirror T,
(75 μm, surface roughness R _a = 0.02 μm). The obtained film was pressed under the conditions of a calendar at a temperature of 80 ° C. and a linear pressure of 30 kg / cm such that the laminated surface of the same laminated coated paper as described above faced each other. Was peeled off to form an ink jet recording layer, thereby producing an ink jet recording medium of the present invention.

Comparative Example 1 To 100 parts of the above silica sol, 40 parts of polyvinyl alcohol (trade name: PVA-135H, manufactured by Kuraray Co., Ltd.) was added to prepare a 4% dispersion. This dispersion was laminated with commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g / m ² ) so that the coating amount was 20 g / m ² (by the extrusion lamination method). A 15 μm layer of polyethylene was laminated on the surface of the coated paper, hereinafter also referred to as a laminated coated paper) and dried to form an ink jet recording layer, thereby producing an ink jet recording body. Comparative Example 2 30 parts of polyvinyl alcohol (manufactured by Kuraray Co., trade name: PVA-135H) and the cationic resin diallyldimethylammonium chloride-acrylamide copolymer (manufactured by Nitto Boseki Co., Ltd., trade name: 100 parts) 10 parts of PAS-J-81). The obtained thickened and aggregated liquid mixture is subjected to a pulverization and dispersion treatment using a sand grinder and a pressure type homogenizer, and pulverized and dispersed until the average particle diameter of the cationic resin-pigment aggregated particles becomes 1.5 μm, and 4% Was prepared. This dispersion is
A product obtained by laminating a commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g / m ² ) so that the coating amount becomes 20 g / m ² (extrusion lamination method on the coated paper surface). 15 μm of polyethylene laminated, hereinafter also referred to as laminated coated paper) and dried to form an ink jet recording layer to produce an ink jet recording medium.

Comparative Example 3 Amorphous silica (manufactured by Tokuyama Corporation, trade name: Fine Seal X-45, average particle size of secondary particles (aggregates): 4.5 μm)
In 100 parts, 30 parts of polyvinyl alcohol (manufactured by Kuraray Co., trade name: PVA-135H), the cationic resin diallyldimethylammonium chloride-acrylamide copolymer (manufactured by Nitto Boseki Co., trade name: PAS-J-8)
1) 10 parts were added to prepare a 10% dispersion. Commercial coated paper (manufactured by Oji Paper Co., Ltd. so that the dispersion coating amount is 20g / m ^2, trade name: OK coat, 127.9g /
m ² ) (15 μm polyethylene laminated on the coated paper surface by extrusion lamination, hereinafter also referred to as laminated coated paper)
And dried to form an ink jet recording layer to produce an ink jet recording medium.

[Evaluation Method] The print density, glossiness, print water resistance and the like of the ink jet recording medium obtained in each of Examples and Comparative Examples were evaluated by the following methods. Table 1 shows the results. Regarding glossiness and print density, commercially available inkjet printers (manufactured by Canon Inc.,
(Trademark: BJC-600J), and the glossiness and print density of a solid portion were evaluated. [Water resistance to printing] After printing on an ink jet recording medium, after standing for 24 hours, a water drop was dropped on the image. After 10 minutes, the water drop was wiped off, and the state of the image portion immersed in the water drop was observed.
(A: There was almost no ink bleeding. B: There was ink bleeding, and the density of the printed portion was low. C: Most of the ink was removed.)

[Glossiness of Printed Area (Glossiness)] The glossiness of the printed area was visually observed from a lateral angle of 20 ° with respect to the printed area, and evaluated in four steps as follows. ：: There is a high shining feeling comparable to a color photograph. ：: Inferior to color photograph, but with high shine. Δ: There is a slight shine. X: There is no shininess at all. [Print Density] The print density of the black solid portion was measured using a Macbeth reflection densitometer (Macbeth).
th, RD-920). The numbers shown in Table 1 are the average values of five measurements.

[0033]

[Table 1]

[0034]

As is clear from Table 1, the method of the present invention is useful for producing an ink jet recording medium having excellent gloss, high print density, and excellent water resistance after printing.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-188287 (JP, A) JP-A-6-199034 (JP, A) JP-A-8-174993 (JP, A) JP-A-5-1990 294057 (JP, A) JP-A-61-3777 (JP, A) JP-A-58-222878 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00

Claims (7)

(57) [Claims] 1. Silica, carion, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, pseudoboehmite, calcium carbonate, satin white, aluminum silicate, smectite, zeolite, magnesium silicate, carbonate Selected from magnesium, magnesium oxide, and diatomaceous earth;
A dispersion liquid of at least one kind of pigment particles in the form of aggregate particles of primary particles having an average primary particle diameter of 0 nm and a cationic resin are mixed to prepare a thickened / agglomerated mixed liquid. The mixture is subjected to a pulverization and dispersion treatment, and the aggregate particles of the cationic resin and the pigment particles in the mixture are pulverized until the average particle diameter becomes 1 μm or less. Forming an ink jet recording layer containing pulverized particles of an aggregate of the cationic resin and pigment particles. 2. The method according to claim 1, wherein the average particle diameter of the pigment particles before the mixing is 300 nm or less. 3. The method according to claim 1, wherein the ink jet recording layer further contains a binder. 4. The method according to claim 1, wherein the pigment particles are selected from amorphous silica particles, zeolite particles, and calcium carbonate particles. 5. The method according to claim 1, wherein 1 to 30 parts by mass of the cationic resin is mixed with 100 parts by mass of the pigment particles.
5. The method for producing an ink jet recording medium according to any one of items 4 to 4. 6. When forming the ink jet recording layer, a coating solution containing pulverized particles of an aggregate of the pigment particles and the cationic resin is applied on a molding surface to form a film. The method according to claim 1, wherein the image is transferred onto at least one surface of a sheet-like support. 7. An ink jet recording layer containing the pulverized particles of the aggregate of the pigment particles and the cationic resin is transferred onto another ink jet recording layer previously formed on at least one surface of the sheet-like support. The method for producing an ink jet recording medium according to claim 6, which is formed.