JP2001180102A - Ink jet recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording body excellent in high lustrous property, ink absorbing property, water resistant property, weather resistance, high printing density and color development property. SOLUTION: In the ink jet recording body provided with an ink receptor layer on a supporting body, the ink receptor layer is provided at least one layer or more of layer constitution and is formed by a method wherein the ink receptor layer is applied on a forming surface to obtain a film and, thereafter, the receptor layer is transferred on the supporting body while at least one layer of the ink receptor layers comprise colloidal particles consisting of secondary particles of average grain size of 10 nm-300 nm, which are obtained by condensing the silica primary grains having the grain size of 3 nm-40 nm, and a water soluble resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording medium, and more particularly to an ink jet recording medium having excellent glossiness, ink absorbency, water resistance, weather resistance, high print density, and excellent color development.

[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 sheet used in this ink jet recording method has a high density of print dots,
It is required that the color tone be bright and vivid, that the ink be absorbed quickly and that no bleeding of the ink occur even when print dots overlap.

In general coated paper, a porous pigment is provided as an ink receiving layer (single layer or multi-layer) as a coating layer, and color and sharpness are controlled to determine image quality. Has been improved. For example, Japanese Patent Application Laid-Open Nos.
No. 3,776, JP-A-63-104878 discloses a method in which primary particles or secondary particles having pores are pigmented (in general, silica, alumina, etc. are used).
And an ink jet recording sheet provided with an ink receiving layer by adding a binder. further,
For the purpose of improving printing quality, as disclosed in JP-B-63-22977, in order to increase the ink absorption speed, a pore having a peak at 0.2 to 10 μm is provided in the uppermost layer of the ink receiving layer, In addition, the absorbed ink has a pore size of 0.0
One that takes in a gap of 5 μm or less to provide a higher quality ink jet recording sheet.

However, in response to the rapid spread of ink-jet printers, in the field of printing, high-gloss photo-like printed matter is required for various publications, packaging and the like. In particular, in the case of color recording, the dot shape (circular shape), dot sharpness, ink absorption, fixing speed,
There is a strong need for a film or coated paper type in terms of ink acceptability such as ink absorption capacity. In order for the ink receiving layer shown above to have porosity, it is necessary to increase the size of the pigment itself or the size of the secondary particles (micron order). When the pigment is too large, not only is the surface of the ink receiving layer not smooth, but also light transmission is prevented, the ink receiving layer becomes opaque, and it is difficult to obtain gloss.

[0005] Many ink jet recording sheets coated with a resin that absorbs ink by dissolution and swelling for the purpose of imparting gloss are commercially available. However, an attempt is made to absorb ink by dissolving and swelling such a resin. However, at present, some gloss can be obtained, but the drying speed of the ink is low, and the moisture resistance and water resistance are not good at present.

In order to obtain smoothness and glossiness, it has recently been proposed to provide two or more ink receiving layers and a glossy layer as an upper layer (for example, JP-A-3-215080, JP-A-3-215080). -256785, JP-A-7-89
220, JP-A-7-101142, JP-A-7-117335, etc.). Colloidal particles or composites of colloidal particles are often used as the main component of these glossy layers. The glossy layer is formed by adding a polymer latex as an adhesive to colloid particles in order to maintain transparency and ink absorbability. When polymer latex is used as an adhesive, small cracks are likely to occur in the coating film, and the small cracks maintain the ink absorption speed, but the periphery of the obtained ink dots is jagged, far from a perfect circle , And the sharpness and delicacy of the image are considerably lacked. In addition, there is a feature that ink spreads easily and dots become large. 360d
Although there is no particular problem at a print level of 360 dpi × 360 dpi, dots are easily spread when recording at a high density of 720 dpi × 720 dpi or more. Also,
The ink fixing layer is provided under the gloss expressing layer in an amount larger than the coating amount of the gloss expressing layer. Since the ink fixing layer uses secondary particles on the order of microns, the entire ink receiving layer is not transparent, and printing is not possible. Since the density is insufficient, it is impossible to obtain shiny high gloss.

For the purpose of improving cracking of the ink receiving layer, an ink receiving layer composed of fine particles having a particle size of 0.1 μ or less and polyvinyl alcohol having a polymerization degree of 4000 or more as disclosed in JP-A-7-117334 is also disclosed. However, the fine particles are a dispersion of primary particles (colloidal silica,
(Alumina sol, etc.), the balance between the ink absorbency and the transparency of the receiving layer cannot be achieved. Since the primary particles themselves do not have ink absorbency, the ink is absorbed in the gaps between the primary particles. Since a dispersion of primary particles is used, an adhesive (binder) must be interposed between the primary particles in order to form a film. If there is an adhesive between the particles,
In order to reduce the ink absorption capacity and completely absorb the portion with a large amount of ink, a high coating amount is indispensable. When the coating amount is high, cracks are easily generated in the coating film. In order to obtain the transparency of the coating film, it is necessary to select a primary particle having a small particle size. When the particle size is small, the ink absorption speed is significantly reduced. Is deteriorated, and there is a fear that the print density is reduced.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 5-32413, an ink receiving layer using colloidal particles including secondary particles formed by aggregating primary particles of boehmite having a crystal thickness of 60 ° or more is disclosed. Was. A structure in which water and a solvent (occupying about 90% or more of the ink component) having a relatively small molecular weight in the ink are absorbed between the small primary particles, and the dye in the ink is absorbed and fixed between the large secondary particles. It is. However, boehmite is a kind of alumina crystal,
The particles have a columnar or needle-like shape. Secondary particles aggregated from needles or columns have poor film-forming properties and are relatively prone to cracking. Further, there is a problem in that the boehmite layer itself is liable to yellow over time, because it is not suitable for an ink having poor coloring properties with alumina (for example, red such as Acid Red 52 (edible red No. 106)). Boehmite has a disadvantage that it is not suitable for general use because of its high cost. A major challenge is to design an ink-receiving layer that has a high ink absorption speed, good color development with the ink, good water resistance and good stability over time, and transparency.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an ink jet recording material having better color development with ink, weather resistance, water resistance, high gloss and high printing density. And

[0010]

[Means for Solving the Problems] Commercially available silica is a powder having a diameter of several microns and has a high ink absorbency but has no transparency, and can be used as a general coated paper. It is not possible to achieve print gloss. In addition, since the particle size is large, it is difficult to make the surface rough and smooth. As a result of diligent studies of the present invention, the transparency of the ink absorbing layer and the ink are improved by forming silica aggregates into colloidal silica particles composed of secondary particles having an average particle diameter of 300 nm or less and selecting a water-soluble resin as an adhesive. We succeeded in designing a porous layer with good absorbency.

In particular, since the present invention uses colloidal silica particles, it is possible to obtain a high gloss ink jet recording material which does not have alumina (boehmite) and has good color development and weather resistance.
The silica colloid particles of the present invention need to be a silica colloid particle solution consisting essentially of secondary particles formed by aggregation of primary particles. In the case of a silica sol in which the primary particles are monodispersed (for example, a commercially available colloidal silica),
The porous layer obtained by coating the base material becomes relatively dense, tends to lose transparency, and a high coating amount is unavoidable in order to have sufficient ink absorbency. If the coating amount is high, the coating film tends to be cracked, and the coating process tends to be complicated. Of course, the primary particles may be partially contained in the silica colloid particle solution of the present invention.

Since the silica colloid particles of the present invention have little self-adhesiveness, it is necessary to add a binder to obtain an ink receiving layer. When the entire ink receiving layer of the ink jet recording medium of the present invention is mainly composed of silica colloid particles and a water-soluble resin (particularly, polyvinyl alcohol is preferable), the transparency of the printed portion can be obtained, and the gloss equivalent to a photograph can be obtained. It is possible. Further, since the entire ink receiving layer is transparent, it can be used as an OHP sheet or the like. Furthermore, when the ink receiving layer of the present invention is coated on a molding surface and then transferred onto a support via an intermediate layer, the gloss is remarkably improved, and a smoother, higher gloss ink jet recording body is obtained. .

The present invention includes, but is not limited to, the following embodiments. [1] In an ink jet recording medium provided with an ink receiving layer on a support, the ink receiving layer has at least one layer structure, and after forming an ink receiving layer on a molding surface, Is formed by being transferred to a support,
In addition, at least one of the ink receiving layers has a particle size of 3 nm or more.
An ink jet recording material comprising a layer containing colloidal particles composed of secondary particles having an average particle diameter of 10 nm to 300 nm and aggregated with 40 nm primary silica particles and a water-soluble resin.

[2] The ink jet recording medium according to [1], wherein the water-soluble resin contains polyvinyl alcohol having a degree of polymerization of 2,000 or more. [3] The ink jet recording medium according to [1] or [2], wherein the water-soluble resin contains polyvinyl alcohol having a saponification degree of 95% or more.

[4] The ink jet recording material according to [1], [2] or [3], wherein the ink receiving layer contains a cationic resin.

[5] The method according to [1], [2], [3] or [4], wherein the intermediate layer is at least one selected from a thermoplastic resin, an adhesive and a pressure-sensitive adhesive. Ink jet recording medium. [6] The inkjet recording according to [1], [2], [3], [4] or [5], wherein the molding surface is a film having a highly smooth surface, a laminated paper, glassine paper, inorganic glass, or a metal surface. body.

[7] In an ink jet recording medium provided with an ink receiving layer on a sheet-like support, the ink receiving layer has at least one layer structure, and the ink receiving layer is coated on a molding surface. A silica colloid comprising a secondary particle formed by agglomerating primary silica particles having a particle diameter of 3 nm to 40 nm, wherein at least one of the ink receiving layers is formed by being transferred to a support after forming the film. An ink jet recording material obtained by applying a coating liquid containing particles and a water-soluble resin, wherein the silica colloid particles have an average particle diameter of 300 nm or less.

[8] In an ink jet recording medium having an ink receiving layer provided on a sheet-like support, the ink receiving layer has at least one layer structure, and the ink receiving layer is coated on a molding surface. After the film is formed, it is formed by being transferred to a support, and at least one of the ink receiving layers is formed.
The layer is obtained by coating a coating liquid containing a silica sol containing secondary particles formed by aggregating primary silica particles having a particle diameter of 3 nm to 40 nm and a water-soluble resin, and the silica sol has an average particle diameter of 300 nm or less. An ink jet recording material characterized by the following. The sol is a colloid using a liquid as a dispersion medium.

Commercially available colloidal silica is a dispersion of primary particles and is different from the silica colloid particles of the present invention. An ink jet recording medium containing colloidal silica is inferior to this patent product in recording density and ink absorption capacity.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, examples of the support include films such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, etc., high quality paper, art paper, coated paper, and the like.
Paper such as cast coated paper, foil paper, kraft paper, polyethylene laminated paper, impregnated paper, vapor-deposited paper, and water-soluble paper, and sheets such as metal foil and synthetic paper are appropriately used.

Next, the ink receiving layer of the present invention will be described in detail. First, a layer mainly composed of the silica colloid particles including secondary particles formed by aggregating primary silica particles having a particle diameter of 3 nm to 40 nm, which constitute the ink receiving layer of the present invention, will be described.

The colloidal silica particles have a particle size of 1000 n.
It means a state in which fine particles of about m or less are uniformly dispersed. The method for preparing the silica colloid particles used in the present invention is not particularly limited. For example, it can be obtained by applying a strong force to a commercially available synthetic amorphous silica (several microns) by mechanical means. That is, it can be obtained by a breaking down method (a method of subdividing a bulk raw material). The silica colloid particles of the present invention may be a slurry. Examples of mechanical means include mechanical methods such as ultrasonic waves, high-speed rotation mills, roller mills, container driving medium mills, medium stirring mills, jet mills, grinders, and sand grinders.

The average particle size in the present invention is a particle size observed with an electron microscope (SEM and TEM) (10,000 to 40).
The electron micrograph taken at a magnification of 10,000 times, the Martin diameter of particles in 5 cm square was measured and averaged. "Particle Handbook", Asakura Shoten, p52, 1991, etc.). The silica colloid particles (substantially 2
The average particle size of the (secondary particle) is 10 to 300 nm, and is preferably adjusted to 20 to 200 nm. Average particle size 300
When the silica colloid particles having a diameter exceeding nm are used, the transparency is remarkably lost, the print density is remarkably reduced, and an ink jet recording medium having a desired high gloss after printing cannot be obtained. On the other hand, when silica colloid particles having an extremely small average particle size are used, an ink absorption speed cannot be obtained.

The primary particles constituting the silica colloid particles used in the ink receiving layer must be adjusted to 3 nm to 40 nm. If it is less than 3 nm, the gap between the primary particles becomes extremely small, and the ability to absorb the solvent and the ink in the ink is significantly reduced. On the other hand, if the primary particles exceed 40 nm, the aggregated secondary particles become large, and the transparency of the ink receiving layer may be reduced.

Since the silica colloid particles produced by the present invention themselves do not have much film-forming properties, the addition of an adhesive is indispensable when provided as an ink receiving layer. As the adhesive (binder), a water-soluble resin is appropriately added and used.
Examples of the water-soluble resin include polyvinyl alcohol (hereinafter referred to as PVA), casein, soybean protein, synthetic proteins, starch, and cellulose derivatives such as carboxymethylcellulose and methylcellulose.
PVA is most effective from the viewpoint of dispersion suitability and paint stability. In particular, PVA having a polymerization degree of 2,000 or more is preferably used as a water-soluble resin in order to obtain dispersibility and ink absorbability.
The degree of polymerization of PVA is more preferably 2000 to 5000.
It is. In order to obtain water resistance, a saponification degree of 95%
The above PVA is effective.

The weight ratio of the solid content of the silica colloid particles and the water-soluble resin produced in the present invention is not particularly limited, but is 10/1 to 1 /.
It is adjusted in the range of 10/10, preferably 10/2 to 10/6. If the amount of the water-soluble resin is large, the pores between the particles become small, and the ink absorption rate may not be obtained.On the other hand, if the adhesive is small, the coating layer cracks,
In some cases, it cannot be used.

Of course, if necessary, other pigments may be appropriately compounded in addition to the silica colloid particles / adhesive (binder) produced in the present invention. For example, colloidal silica (dispersion of primary particles), kaolin, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, smectite, zeolite, silicate Magnesium, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene-based plastic pigment,
Various pigments known and used in the general coated paper field, such as urea resin-based plastic pigment and benzoguanamine-based plastic pigment, are appropriately used. However, in order to maintain the smoothness and transparency of the coating layer, the amount of other pigment used is preferably adjusted to 20% or less based on the silica colloid particles produced in the present invention. Further, in order to maintain the transparency of the ink receiving layer, the average particle size of the pigment added to the silica colloid particles is desirably 2 μm or less.

A cationic resin may be added to the ink receiving layer of the present invention for use. Thereby, the ink fixability can be improved. Examples of the cationic resin to be added include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine, or derivatives thereof, acrylic resins having a tertiary amino group and a quaternary ammonium group, and diacrylamine.
The amount of the cationic resin added is adjusted in the range of 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the pigment. In addition, various auxiliaries such as a dispersant, a thickener, a defoaming agent, a coloring agent, an antistatic agent, and a preservative used in the production of general coated paper are appropriately added.

The coating amount is not particularly limited.
It is adjusted to 〜100 g / m ² , more preferably 5 to 60 g / m ² . If the coating amount is small, it is difficult to obtain a uniform coating film,
If the amount is too large, the effect is saturated and the coating film is liable to crack. For example, in order to obtain a high coating amount of 15 g / m ² or more, a method of thickening and increasing the concentration of the coating liquid can be used, and the coating is realized by two or more coatings.

Although the layer containing the silica colloid particles produced in the present invention has been described, this layer may be a single layer or a multilayer. When the ink receiving layer is composed of only the silica colloid particle layer, the color development, printing density, glossiness, and transparency are the best. Of course, even if the silica colloid particle coating layer is provided in the upper layer and another ink receiving layer is provided in the lower layer, the high ink absorption rate, color forming property,
An ink jet recording medium having high printing density, high gloss, good weather resistance and good water resistance can be obtained. In order to maintain gloss and shininess after printing, the coating amount of the layer containing silica colloid particles as a main component is preferably adjusted to 50 to 100% with respect to the entire ink receiving layer. Although a certain level of gloss can be obtained with less than 50%, the silica colloid particle-containing layer should be 50 to 1%.
In the embodiment where the content is set to 00%, gloss and shininess comparable to photographs are obtained.

Next, the other ink receiving layer as the lower layer (layer close to the support) will be specifically described. Pigments used in other ink receiving layers (average particle size: 0.5μ or more)
Examples thereof include synthetic amorphous silica, clay, alumina, smectite and the like, and various pigments known and used in the general coated paper field. From the viewpoints of color development and print density,
Synthetic amorphous silica is preferably used.

As the adhesive (binder), there may be mentioned water-soluble resins such as PVA, casein and starch described above, or conventionally known ones such as latex and synthetic resin emulsions. The amount of the adhesive added is adjusted in the range of 5 to 150 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the pigment. Further, a cationic resin used for the purpose of improving the ink fixing property can also be added, and examples thereof include the above-mentioned amine resins. The amount of the cationic resin to be added is adjusted in the range of 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the pigment. In addition, various auxiliaries such as a dispersant, a thickener, an antifoaming agent, a coloring agent, an antistatic agent, and a preservative used in the production of general coated paper are also appropriately added.

The coating amount of the other ink receiving layer is not particularly limited, but is preferably adjusted to ³ to 30 g / m ² . If the amount is too small, there is no point in providing the ink receiving layer, while if the amount is too large, the effect is saturated and is meaningless.

As a coating coater for obtaining any ink receiving layer, various known coating apparatuses such as 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. Can be exemplified.

According to the present invention, the ink receiving layer has at least one layer structure, and is formed by coating the ink receiving layer on a molding surface and then transferring the ink receiving layer to a support. is there. For example, an ink receiving layer (including an upper layer and a lower layer) is formed on a molding surface by a coating device. An ink receiving layer is formed on a molding surface, and an intermediate layer having tackiness or adhesiveness is provided on a support (or an ink receiving layer) in some cases, and the intermediate layer and the ink receiving layer (or the support) are bonded to each other. An ink receiving layer is provided by peeling only the surface. When the ink receiving layer is formed using the molding surface in this way,
Better gloss is obtained. When the layer containing the silica colloid particles is provided using the molding surface, particularly excellent gloss can be obtained. In the following, an ink receiving layer is formed by coating on a molding surface, an intermediate layer is provided on a support, and the ink receiving layer and the intermediate layer are bonded to face each other, and a case where the molding surface is peeled off will be described in detail. An embodiment in which an intermediate layer is provided in the ink receiving layer can be similarly performed.

As a bonding method, a laminating method is effective. Known laminating methods such as a dry laminating method, a wet laminating method, a hot melt laminating method and an extrude laminating method can be exemplified as the laminating method. In the wet lamination, the dry lamination, and the hot melt lamination methods, an intermediate layer having an adhesive property is provided by coating an adhesive resin or an adhesive on a support,
After laminating and pressing the intermediate layer and the ink receiving layer so that they face each other, the molding surface is peeled off, and a desired ink jet recording body is obtained. In the extrusion lamination method, polyethylene heated and melted at 280 to 320 ° C. in a melt extruder (the same method is used when a resin other than polyethylene is used) is flowed over the surface of the support, and has an ink receiving layer. After laminating with the molded body and cooling and pressing with a cooling roll, the molded body is peeled off to obtain a desired ink jet recording medium.

In the case where a pressure-sensitive adhesive is used as the intermediate layer, the support is coated and dried using a known and publicly-known coating method such as a bar coater, a roll coater, and a lip coater. After joining, the molding surface is peeled off to obtain a desired inkjet recording sheet. The coating amount of the intermediate layer is not particularly limited as long as the ink receiving layer and the support can be adhered to each other. However, even when any of a thermoplastic resin, an adhesive and a pressure-sensitive adhesive is used, about ² to 50 g / m ² is used. preferable. If the coating amount is small, it is difficult to obtain a sufficient adhesive strength, while if it is large, the effect is saturated and is meaningless.

As the polymer resin used for the intermediate layer, a thermoplastic resin (for example, ethyl cellulose, vinyl acetate resin and its derivatives, polyethylene, ethylene vinyl acetate copolymer, polyvinyl alcohol, acrylic resin, polystyrene and its copolymer) And various publicly known thermoplastic resins such as polyisobutylene, hydrocarbon resin, polypropylene, polyamide resin, polyester resin, etc.), adhesives (thermosetting resins such as urea resin, phenol resin, epoxy resin, polyisocyanate resin). , Polyvinyl acetal / phenolic resin, rubber / phenolic resin, epoxy / nylon resin, etc., composite polymer type adhesives, rubber type adhesives such as latex type rubber bases, hydrophilic natural polymer adhesives such as starch, glue, casein Various publicly known adhesives such as Pressure-sensitive adhesives (including various known and publicly-known pressure-sensitive adhesives such as solvent-type pressure-sensitive adhesives, emulsion-type pressure-sensitive adhesives, hot-melt-type pressure-sensitive adhesives, and delayed-type pressure-sensitive adhesives). Is appropriately used.

Materials used for the molding surface include films having high surface smoothness, such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, etc., polyethylene laminated paper, glassine paper, impregnated paper. Papers such as vapor-deposited paper, flexible sheets such as metal foil and synthetic paper, and plates having a highly smooth surface such as inorganic glass, metal and plastic are appropriately used. In particular, polymer films (polyethylene, polypropylene, polyester, etc.), polyethylene-laminated paper, glassine paper, and inorganic glass are preferable from the viewpoints of suitability for coating and suitability for peeling the molding surface and the ink receiving layer.

The molding surface is preferably smooth in terms of glossiness, and the surface roughness (JIS B0601) of the molding surface is Ra
Is preferably 0.5 μm or less, and more preferably Ra is 0.05 μm or less. The molding surface may be left untreated, but in order to improve the releasability of the molding surface and the ink receiving layer, the molding surface may be coated with a releasable resin such as silicone or fluororesin. Can be used. From the viewpoint of suitability for coating (such as cissing), it is also effective to make the molding surface hydrophilic by corona discharge or plasma treatment.

The step of coating the ink receiving layer when transferring to the support via the intermediate layer is the reverse of the general coating step.
That is, the uppermost layer of the ink receiving layer (the layer containing silica colloid particles) is first coated on the molding surface, and the other ink receiving layer is sequentially coated thereon. The ink receiving layer of the ink jet recording medium obtained by transferring this to a support has the same lamination order as the above-mentioned coated sheet in the order of the upper layer and the other ink receiving layer (lower layer).

The ink used in the ink jet recording method of the present invention comprises, as essential components, a dye for forming an image and a liquid medium for dissolving or dispersing the dye, and, if necessary, various dispersants and an interface. It is adjusted by adding an activator, a viscosity adjuster, a specific resistance adjuster, a pH adjuster, a fungicide, a stabilizer for dissolving or dispersing the recording agent, and the like.

Examples of the recording agent used in the ink include direct dyes, acid dyes, basic dyes, reactive dyes, edible dyes, disperse dyes, oil dyes, and various pigments. Can be used without. 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, There is no particular problem in use at a ratio of about 0.1 to 20% by weight.

As the solvent for 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.

[0045]

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.
Unless otherwise specified, parts and percentages in the examples are parts and percentages of solids excluding water, and represent parts by weight and percentage by weight, respectively. All the ink jet recording materials obtained in the present invention were processed by a super calender (linear pressure: 20 kg / cm) and then used for evaluation.

[Silica colloid particles A] Synthetic amorphous silica having an average particle diameter of 9 μm (Nihon Silica Kogyo Co., trade name: Ni
psi LP, primary particle diameter: 16 nm), and after dispersing with a sand grinder, applying ultrasonic waves and repeating the dispersing operation of the sand grinder and ultrasonic waves until the average particle diameter becomes 50 nm, thereby preparing an 8% aqueous solution. did. [Silica colloid particles B] Synthetic amorphous silica having an average particle diameter of 9 µm (trade name: Nipsil N, manufactured by Nippon Silica Industry Co., Ltd.)
S, primary particle diameter: 21 nm) and dispersed by a sand grinder.
The dispersion operation of the sand grinder and the ultrasonic wave was repeated until the thickness became 0 nm, thereby preparing a 12% aqueous solution. [Silica colloid particle C] Synthetic amorphous silica having an average particle diameter of 3 μm (trade name: Nipsil H, manufactured by Nippon Silica Industry Co., Ltd.)
D-2, primary particle diameter: 11 nm), and after dispersing with a sand grinder, applying ultrasonic waves and repeating the operation of dispersing the sand grinder and the ultrasonic waves until the average particle diameter becomes 200 nm. Prepared. [Silica colloid particles D] Synthetic amorphous silica having an average particle diameter of 9 μm (manufactured by Nippon Silica Industry Co., Ltd., trade name: Nipsil L)
P, primary particle diameter: 16 nm), dispersed by a sand grinder, and then sonicated to give an average particle diameter of 50.
The dispersion operation of the sand grinder and the ultrasonic wave was repeated until the thickness became 0 nm, thereby preparing a 15% aqueous solution.

Example 1 An 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., trade name: PVA-124, degree of polymerization: 2400, degree of saponification: 98.5%) with 100 parts of silica colloid particles A was used as a Mayer. A PET film (75 μm, trade name: Lumirror T, surface roughness Ra = 0.02 μm, manufactured by Toray Industries, Inc.) used as a molding surface was dried with a bar so that the coating amount was 20 g / m ² . Next, an acrylic ester adhesive (manufactured by Nippon Carbide Industry Co., Ltd., trade name: A-02) is applied to the surface of the coating layer.
Was dried so that the coating amount was 10 g / m ² . Subsequently, the adhesive is laminated coated paper (commercial coated paper (manufactured by Shin-Oji Co., Ltd., trade name: OK coat, 127.9 g / m2).
² ) Lamination processing (15 μm polyethylene laminated on the coated paper surface by extrusion lamination method))
Crimping was performed using a kg / cm calendar. Subsequently, the PET film was peeled off to produce an ink jet recording medium of the present invention.

REFERENCE EXAMPLE 1 An aqueous 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-124, degree of polymerization: 2400, degree of saponification: 98.5%) with 100 parts of silica colloid particles A was used. The surface of the support was coated and dried with a bar so that the coating amount was 20 g / m ² , thereby producing an ink jet recording body.
However, the support is a commercially available coated paper (manufactured by Shin-Oji Co., Ltd., trade name: OK coated, 127.9 g / m ² ), which is laminated (15 μm of polyethylene on the coated paper surface by an extrusion lamination method). , Hereinafter referred to as laminated coated paper).

REFERENCE EXAMPLE 2 An aqueous 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-117, degree of polymerization: 1800, degree of saponification: 98.5%) with 100 parts of silica colloid particles A was used. The surface of the laminated coated paper was coated and dried with a bar so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Reference Example 3 An aqueous 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-224, degree of polymerization: 2400, degree of saponification: 88.5%) with 100 parts of silica colloid particles A was used as a Mayer. The surface of the laminated coated paper was coated and dried with a bar so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

REFERENCE EXAMPLE 4 An 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-135H, degree of polymerization: 3500, degree of saponification: 99% or more) with 100 parts of silica colloid particles A was mixed with a Meyer bar. The coating was dried on the surface of the laminated coated paper so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Reference Example 5 An 8% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., trade name: PVA-140H, degree of polymerization: 4000, degree of saponification: 99% or more) with 100 parts of silica colloid particles A was used as a Meyer bar. The coating was dried on the surface of the laminated coated paper so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Reference Example 6 A 12% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-124, degree of polymerization: 2400, degree of saponification: 98.5%) with 100 parts of colloidal silica particles B was used. The surface of the laminated coated paper was coated and dried with a bar so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Reference Example 7 A 15% aqueous solution obtained by mixing 100 parts of silica colloid particles C with 40 parts of PVA (manufactured by Kuraray Co., trade name: PVA-124, degree of polymerization: 2400, degree of saponification: 98.5%) was mixed with Mayer. The surface of the laminated coated paper was coated and dried with a bar so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Comparative Example 1 A 15% aqueous solution obtained by mixing 40 parts of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-124, degree of polymerization: 2400, degree of saponification: 98.5%) with 100 parts of silica colloid particles D was used as a Mayer. The surface of the laminated coated paper was coated and dried with a bar so that the coating amount was 20 g / m ² to produce an ink jet recording medium.

Comparative Example 2 Synthetic amorphous silica having an average particle diameter of 3 μm (trade name: Nipsil HD-2, manufactured by Nippon Silica Industry Co., Ltd., primary particle diameter: 1)
100 parts of PVA (manufactured by Kuraray Co., trade name: P
VA-124, degree of polymerization: 2400, degree of saponification: 98.5
%) Using a 15% aqueous solution mixed with 40 parts, and coated and dried on a laminate coated paper with a Mayer bar so that the coating amount was 20 g / m ² , to produce an ink jet recording material.

Comparative Example 3 Synthetic amorphous silica having an average particle diameter of 9 μm (trade name: Nipsil LP, manufactured by Nippon Silica Industry Co., Ltd., primary particle diameter: 16 n)
m) 100 parts of PVA (Kuraray Co., Ltd., trade name: PVA)
-124, polymerization degree: 2400, saponification degree: 98.5%)
Using a 15% aqueous solution in which 40 parts were mixed, the composition was coated and dried on a laminate coated paper with a Mayer bar so that the coating amount was 20 g / m ² , thereby producing an ink jet recording body.

Comparative Example 4 Alumina sol having an average particle diameter of 10 × 100 nm as a primary particle dispersion (alumina sol, manufactured by Nissan Chemical Industries, Ltd.)
100) PVA (manufactured by Kuraray Co., trade name: P
VA-124, degree of polymerization: 2400, degree of saponification: 98.5
%) Using an 8% aqueous solution mixed with 40 parts, and coated and dried on a laminate coated paper with a Meyer bar so that the coating amount was 20 g / m ² , to produce an ink jet recording material.

COMPARATIVE EXAMPLE 5 100 parts of anionic colloidal silica having an average particle diameter of 65 nm (trade name: Snowtex YL, manufactured by Nissan Chemical Co., Ltd.), which is a dispersion of primary particles, was mixed with PVA (trade name: PVA, manufactured by Kuraray Co., Ltd.). -124, degree of polymerization: 2400, degree of saponification: 9
(8.5%) A 15% aqueous solution in which 10 parts were mixed was applied and dried on the surface of the laminated coated paper with a Meyer bar so that the coating amount was 20 g / m ² , thereby producing an ink jet recording medium.

Comparative Example 6 A styrene / butadiene-based latex (trade name: Nipol, manufactured by Zeon Corporation) was added to 100 parts of silica colloid particles A.
LX415A, average particle size: 110 nm, Tg = 27
(C) 100% of a 15% aqueous solution was applied to the surface of a laminate coated paper using a Meyer bar so that the coating amount was 20 g / m ^2, and an ink jet recording body was manufactured.

Comparative Example 7 A 10% aqueous solution of PVA (manufactured by Kuraray Co., Ltd., trade name: PVA-117, degree of polymerization: 1800, degree of saponification: 98.5%) was used. ^The coating was dried on a laminate coated paper so as to obtain No. ² , thereby producing an ink jet recording medium.

Comparative Example 8 Commercially available ink jet glossy paper GP-101 (manufactured by Canon Inc.) having an ink fixing layer and a gloss developing layer was used.

[Evaluation Methods] The coating film water resistance, ink absorbency, ink absorption capacity, and the like of the ink jet recording materials obtained in Example 1, Reference Examples 1 to 7, and Comparative Examples 1 to 8 were evaluated by the following methods. did. Regarding glossiness and ink absorbency, a commercially available inkjet printer (manufactured by Canon Inc., trademark: BJ
C-600J) shows the glossiness, ink absorbency, and print density of a solid portion when recording is performed at C-600J).

[Water Resistance] Water droplets were dropped on the ink jet recording sheet, and after 30 minutes, the water droplets were wiped off, and the portion immersed in the water droplets was rubbed with a hand to evaluate the water resistance in four steps.
(A: No change was observed in the ink receiving layer.
The ink receiving layer was slightly removed. Δ: The ink receiving layer was partially removed. X: The ink receiving layer was completely removed. )

[Ink Absorption] a. (Ink absorption speed) Printing each single color of yellow, magenta, and cyan, and sticking high quality paper on the printing surface printed every 5 seconds immediately after printing,
Observe whether the ink transfers to woodfree paper. The time until no transfer occurs at all is measured. The measured number of seconds was evaluated in four steps (◎: 5 seconds or less, ：: 5 to 10 seconds, Δ: 1).
0 to 30 seconds, x: 30 seconds or more). When the time until the ink dries is 10 seconds or less, the ink absorbency is excellent.

B. (Ink absorption capacity) Using an A4 size inkjet recording medium, yellow,
Magenta and cyan colors of 10cm x 10cm square
1 minute, 2 minutes immediately after printing, to check whether the ink overflows from the coating layer.
After 5 minutes, the high-quality paper is stuck to the printed surface, and it is observed whether or not the ink is transferred to the high-quality paper. The time until the transfer was completely stopped was measured and evaluated in four steps as follows. A: Within 1 minute. ： １: 1 minute or more and 2 minutes or less. Δ: 2 minutes or more and 5 minutes or less. X: 5 minutes or more.

[Print Density] The print density of the solid black portion was measured using a Macbeth reflection densitometer (Macbeth, RD-920). The numbers shown in the table are the average values of five measurements.

[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 the same level of shine as a silver halide color photograph. ：: Inferior to color photograph, but with high shine. Δ: comparable to printed product of coated paper. ×: comparable to ordinary PPC paper. [Dot shape] 100 to 2 dots by optical microscope
Zoom in 00 times and observe the shape of the dot with eyes.

[0069]

[Table 1]

As is evident from Table 1, the ink jet recording medium obtained by the constitution of the present invention has good ink absorption and ink absorption capacity, and after receiving the ink, the dots have a perfect circular shape and high gloss. An ink jet recording medium having high print density and high fineness.

[0071]

The ink-jet recording medium of the present invention has high gloss and excellent ink coloring properties, ink-jet recording (printing) suitability, high printing density, and weather resistance.

In the present invention, it is possible to obtain a high gloss ink jet recording material having good color development of ink, high ink absorption speed, high print density, good weather resistance, good ink fixability and good printability. The primary silica particles are likely to be formed into spherical shapes,
The obtained secondary particles are easy to form a film, and the coating film is less likely to crack. Further, silica has good coloring properties of ink and is low in price, so that it may be extended to general use.

Claims (4)

[Claims] In an ink jet recording medium provided with an ink receiving layer on a support, said ink receiving layer has at least one layer structure, and is formed by coating an ink receiving layer on a molding surface. Then, at least one of the ink receiving layers has a particle size of 3
An ink jet recording material comprising a layer containing colloidal particles composed of secondary particles having an average particle diameter of 10 nm to 300 nm and primary particles of silica having a diameter of 40 nm to 40 nm and a water-soluble resin. 2. The ink receiving layer according to claim 1, wherein the ink receiving layer is formed by coating the ink receiving layer on a molding surface, and then transferring the ink receiving layer to a support via an adhesive or adhesive intermediate layer. 2. The ink jet recording material according to 1. 3. The ink-jet recording medium according to claim 1, wherein the molding surface is a film having a highly smooth surface, laminated paper, glassine paper, inorganic glass, or a metal surface. 4. The colloid particles obtained by pulverizing and dispersing an aggregate obtained by aggregating primary silica particles having a particle size of 3 nm to 40 nm by mechanical means.
Or the ink-jet recording material according to 3.