JP2006326949A - Manufacturing method of coating solution for inkjet recording layer, and inkjet recording object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an inkjet recording object which has so good an ink absorbency as to enable high-speed recording, excels in surface smoothness, brings about a high image density and an extremely good uniformity of an image and also excels for both a dye ink and a pigment ink, and the recording object, and particularly to provide the inkjet recording object which has good rubbing properties of a part printed with the pigment ink and can be utilized for printing with little difference between a white paper gloss and a printed part gloss, for a photographic use, etc. <P>SOLUTION: A dispersion obtained by mixing/dispersion of a cationic compound A and an agglomerate pigment of an average particle diameter of 1 μm or more is added to/dispersed in a slurry which contains at least one kind of superfine pigment of an average particle diameter of 0.5 μm or less selected from an agglomerate particulate of a silica-cationic compound B, an alumina agglomerate particulate and an alumina hydrate agglomerate particulate. A dispersion thus obtained and coating that contains a binder are adjusted to each other and the coating is applied so as to obtain the inkjet recording object. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for producing a coating liquid in which a matting pigment is added to a slurry of an ultrafine pigment, and an ink jet recording material formed using the coating liquid.
More specifically, it is a method for producing a coating liquid that can uniformly disperse the matted pigment without impairing the dispersion state of the ultrafine pigment slurry, and the coating liquid is excellent in dispersion stability. An ink jet recording material prepared with a coating material using the coating liquid has good ink absorbability, extremely good image uniformity, particularly good printing portion scratching of pigment ink, and white paper gloss and pigment ink. An ink jet recording material that can be used for printing, photographic use, and the like with a small difference in gloss when printed is printed.

  The ink jet recording method that ejects water-based ink from a fine nozzle toward the ink jet recording body to form an image on the surface of the ink jet recording body has low noise during recording, easy formation of a full color image, high speed It is widely used for photographs and various printing applications because it can be recorded and the recording cost is lower than other printing apparatuses.

  Particularly in recent years, high-definition and high-speed printers have made it possible to obtain images comparable to silver salt photography and plate-making multicolor printing. However, the quality of recorded images varies greatly depending on the recording medium, and the recording bodies are largely divided according to the purpose, such as for photographs, for printing, and for general offices.

  In order to achieve high image quality and high storage stability, the ink itself has been improved, and together with water-based dye inks (hereinafter referred to as dye inks) that use a highly hydrophilic colorant, which has been the mainstream, water resistance Ink (hereinafter referred to as “pigment ink”) in which a hydrophobic coloring pigment is dispersed, which has excellent properties and light resistance, has been put into practical use. There is a strong demand for a recording material that can realize high image quality for both the recording material, dye ink, and pigment ink. In particular, there is a strong demand for an ink jet recording material that can be used for printing, photographic use, and the like, in which the pigment ink printing portion has good rubbing properties, and the difference in gloss of the printing portion when printed with white paper and pigment ink is small.

  In order to realize image recording density, ink absorbability, and the like, there is an inkjet mat paper in which a matte pigment having an average particle diameter of 1 μm or more, a cationic polymer, and a paint mainly composed of a binder are coated on a support (for example, Patent Documents 1 and 2). Such an ink jet recording material has a low image density as well as a glossiness, and the circularity of the dots cannot be obtained. Therefore, the uniformity of the image is extremely low.

  In order to obtain gloss and high image quality, a method has been proposed in which a cationic polymer and an aggregate pigment are mixed and finely dispersed using an ultrasonic homogenizer or a high-pressure homogenizer (see Patent Documents 3 to 6). The ultrafine pigment slurry obtained by each of the above methods has high transparency, and the ink jet recording material produced using the slurry has excellent ink absorbability and image uniformity, but the surface smoothness of the recording layer is extremely high. Therefore, the scratching property of the pigment ink printing part is inferior. Further, since the printed portion when printed with pigment ink is covered with the ultrafine pigment ink, there is a problem that gloss is more likely to occur than the blank paper portion, and glossy spots on the blank paper and the printed portion are generated.

  There has been an attempt to use a fine pigment of 500 nm or less on a water-resistant support with a matted pigment of 1 to 10 μm and a colored pigment of 1 μm or less for use in printing proofing (see Patent Document 7). The addition method of is not described. When a fine pigment slurry is prepared in advance and a matted pigment having a desired particle size is added to the slurry, there is a problem that the matted pigment and the fine pigment are aggregated. Even if the agglomerated dispersion is further dispersed, the matted pigment does not have a desired particle size, and a uniform dispersion cannot be obtained. Further, when a matting pigment having a desired particle size is added to the pigment before adjusting the fine pigment slurry, the matting pigment is simultaneously refined at the time of fine slurry formation (so-called pulverization dispersion). There was a problem that the original effect disappeared.

JP 58-110287 A Japanese Patent Publication No. 7-37175 JP-A-10-181190 JP-A-10-181191 JP 11-321079 A JP 2000-094830 A JP 2004-001449 A

The present invention solves the above-mentioned problems and is produced by using a coating liquid production method for uniformly adding a matted pigment without impairing the dispersion stability of the ultrafine pigment slurry, and the coating liquid. An object of the present invention is to provide an ink jet recording material.
Further, the recording layer obtained using the coating liquid of the present invention has excellent acceptability for ink jet recording ink, and when used as the outermost layer of the ink jet recording material, the ink absorption is good and the image is uniform. In particular, the ink-jet recording material can be used for printing, photographic use, etc., which has excellent printing properties, particularly good scratch resistance of the printing portion of pigment ink, and small difference in gloss of the printing portion when printed with white paper and pigment ink. It is done.

  As a result of intensive studies to solve the above problems, the present inventors have found that this can be achieved by employing the following production method and recording material, and have reached the present invention.

(1) In the method for producing a coating liquid for an ink jet recording layer containing a pigment and a binder, a dispersion obtained by mixing / dispersing the cationic compound A and an aggregate pigment having an average particle diameter of 1 μm or more is treated with silica- It is obtained by adding / dispersing to a slurry containing at least one ultrafine pigment having an average particle diameter of 0.5 μm or less selected from aggregate fine particles of cationic compound B, alumina aggregate fine particles, and alumina hydrate aggregate fine particles. A method for producing a coating liquid for an ink jet recording layer.

(2) The silica-cationic compound B aggregate fine particle slurry is obtained by mixing silica-cationic compound B aggregate particles obtained by mixing dry silica and cationic compound B in advance in an amount of 0.01 to 0.5 μm. (1) The manufacturing method of the coating liquid for inkjet recording layers as described in (1).

(3) The method for producing a coating liquid for an ink jet recording layer according to any one of (1) and (2), wherein the aggregate pigment is wet silica.

(4) The method for producing a coating liquid for an ink jet recording layer according to any one of (1) to (3), wherein the main components of the cationic compound A and the cationic compound B have the same structural formula.

(5) The method for producing a coating liquid for an inkjet recording layer according to any one of (1) to (4), wherein the aggregate pigment contains 0.5 to 15% by mass with respect to the total pigment mass.

(6) The said binder is a manufacturing method of the coating liquid for inkjet recording layers in any one of (1)-(5) whose polyvinyl alcohol with a polymerization degree of 3000 or more is a main component.

(7) A method for producing an ink jet recording material, comprising applying the coating liquid according to (1) to (6) on a support to provide an ink jet recording layer.

(8) An ink jet recording material, wherein an ink jet recording layer is provided by coating the coating liquid according to (1) to (6) on a support.

(9) An ink jet recording body having at least one recording layer, wherein the outermost layer is coated by using the coating liquid described in (1) to (6). .

  In the coating liquid of the present invention, the matted pigment is uniformly dispersed in the ultrafine pigment slurry, and the stability is very good. The ink jet recording material obtained by coating using the coating liquid of the present invention has excellent acceptability for ink, and when used as the outermost layer of the ink jet recording material, the ink absorbency is good, and the image Provides an ink jet recording material that can be used for printing, photographic use, etc., with extremely good uniformity of the image, excellent printing portion scratching of the pigment ink, and small difference in gloss of the printing portion when printed with white paper and pigment ink. It is possible.

  The present invention relates to a coating liquid obtained by adding / dispersing a dispersion obtained by dispersing a matting pigment having an average particle diameter of 1 μm or more in a cation solution to an ultrafine pigment slurry having an average particle diameter of 0.5 μm or less, and the coating liquid. The present invention relates to an ink jet recording material using a working liquid.

(Cationic compounds A and B)
Examples of the cationic compounds A and B used in the present invention include the following.
1) Polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine, and derivatives thereof 2) Acrylic resin having secondary amino group, tertiary amino group, and / or quaternary ammonium group 3) Polyvinylamine Polyvinylamidines, 5-membered cyclic amidines 4) Dicyan cationic resins such as dicyandiamide-formalin polycondensates 5) Polyamine cationic resins such as dicyandiamide-diethylenetriamine polycondensates 6) Epoxychlorohydrin-dimethylamine addition polymerization things 7) dimethyldiallylammonium chloride -SO ₂ copolymer 8) diallylamine -SO ₂ copolymer 9) dimethyldiallylammonium chloride polymer 10) polymer of allyl amine salt 11) dialkylamino ethyl (Meth) acrylate quaternary ammonium salt polymer 12) Acrylamide-diallylamine salt copolymer 13) Polyaluminum salt such as polyaluminum chloride, polyaluminum acetate, and polyaluminum lactate One kind of cationic compound or two or more kinds of cationic compounds are used in combination There is no problem.
Among the above cationic compounds, aluminum salts such as 1) 5-membered ring amidines, 2) polyaluminum chloride, polyaluminum acetate, and polyaluminum lactate are preferably used.
Among these, a cationic polymer is preferable from the viewpoint of dispersibility, and a cationic resin having primary, secondary, and tertiary amine groups is particularly preferable because of good dispersibility and print storage stability. Amidines that form a 5-membered ring are most preferred.
The molecular weight of the cationic polymer is not particularly limited, but is preferably 10,000 to 100,000 in view of dispersibility and dispersion stability. More preferably, it is 20,000 to 70,000. When the molecular weight is less than 10,000, the dispersibility is poor, and when the molecular weight exceeds 100,000, the dispersion stability may be inferior.
In addition, it is preferable that the compounding quantity of a cationic compound is 1-30 mass parts with respect to 100 mass parts of pigments (solid content), and it is more preferable that it is 2-15 mass parts.
In the present invention, a dispersion obtained by mixing / dispersing an cationic pigment A and an aggregate pigment having an average particle diameter of 1 μm or more is used as an aggregate fine particle of silica-cationic compound B, an alumina aggregate fine particle, an alumina hydrate. When adding a slurry containing at least one ultrafine pigment having an average particle size of 0.5 μm or less selected from aggregate fine particles to agglomerate or thicken the dispersion, it is difficult to obtain a uniform coating solution. It is preferable to avoid aggregation and thickening as much as possible. In the present invention, it is most desirable that the main components of the cation compound A and the cation compound B have the same structure because aggregation and thickening may occur due to differences in pH and molecular structure even in the same cationic system. .

(Aggregate pigment of 1 μm or more)
Aggregate pigments of 1 μm or more (hereinafter referred to as matted pigments) are gas phase method silica, wet method silica, mesoporous silica, alumina, alumina hydrate, alumina silicate, kaolin, clay, calcined clay, zinc oxide, tin oxide, Magnesium sulfate, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, smectite, zeolite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, urea resin plastic pigment, etc. Various publicly known pigments are used. Wet silica and alumina are preferably selected in order to reduce the difference in ink absorbency, pigment rubbing property, glossiness of blank paper and printing portion gloss when printed with pigment ink. Wet silica is most preferred.
If the average particle size of the matted pigment is 1 to 30 μm, there is no problem. To maintain the smoothness of the pigment ink printing part, the difference in printing part gloss when printing with blank paper and pigment ink is 1 The range of 0.5 to 15 μm is preferable, and the most preferable range is 2 to 5 μm.
In the present invention, the matted pigment contains at least one ultrafine pigment having an average particle diameter of 0.5 μm or less selected from silica-cationic compound B aggregate fine particles, alumina aggregate fine particles, and alumina hydrate aggregate fine particles. In order to prevent aggregation and thickening when added to the slurry to be added, it is necessary to disperse the matted pigment in the cationic compound A in advance. The cationic compound A is appropriately selected from the above cationic compounds.
When the matting pigment is previously dispersed in a cationic compound and then added to the ultrafine pigment, a uniform dispersion can be obtained without causing aggregation or thickening. In the surface layer obtained by coating with a coating solution containing such a dispersion, the matted pigment is uniformly distributed, and the uniformity of the image, particularly the uniformity of the printed image portion of the pigment ink, is excellent.
The amount of the matting pigment / cationic compound A is not particularly limited, but is preferably in the range of 100/1 to 100/30, and most preferably in the range of 100/5 to 100/15. When the blending amount of the cationic compound A is less than 100/1, the dispersion stability is poor. On the other hand, when the amount of the cationic compound A is greater than 100/30, the effect is saturated.

  The matting pigment of 1 μm or more is preferably in the range of 0.5 to 15% by mass relative to the total pigment mass in the paint. More preferably, it is the range of 1-10 mass%. The most preferable range is 2 to 6% by mass. When the amount is less than 0.5% by mass, the pigment rubbing property is insufficient, and in particular, the difference between the gloss of the printed portion when printing with the blank paper gloss and the pigment ink may be noticeable. If it exceeds 15% by mass, the pigment rubbing property may be saturated and the image quality may deteriorate.

(Ultra fine pigment with an average particle size of 0.5 μm or less)
The ultrafine pigment having an average particle size of 0.5 μm or less is selected from at least one of aggregate particles of silica-cationic compound B, alumina, and alumina hydrate. Silica is not limited, but after adding alkali to dry silica, mesoporous silica, and colloidally dispersed silica seed solution, a feed solution comprising at least one selected from active silicic acid aqueous solution and alkoxysilane is added to the seed solution. A secondary silica dispersion obtained by growing silica fine particles by adding a small amount is preferably selected. The ultrafine pigment is most preferably vapor-phase silica or alumina in terms of the film-forming property of the coating layer and the image density after printing.
The method for producing the aggregated fine particles of silica-cationic compound B is not particularly limited. For example, silica is added to an aqueous solution of cationic compound B, and a strong force is obtained by mechanical means, so-called breaking down method (a method of fragmenting a bulk material). Can be obtained by pulverization / dispersion. Mechanical means include: ultrasonic homogenizer, pressure homogenizer, liquid collision homogenizer, high-speed rotary mill, roller mill, container drive medium mill, medium agitator mill, jet mill, mortar, disintegrator (covered in a bowl-shaped container) And a mechanical method such as a sand grinder or the like. Reduction of the particle size can be achieved by classification and repeated grinding. From the standpoint of ink absorbency and image density, dry silica-cationic compound B aggregate particles are most preferred.

  The blending amount of silica / cationic compound B in the aggregate particles of silica-cationic compound B is not particularly limited, but is preferably in the range of 100/1 to 100/30, and most preferably in the range of 100/5 to 100/15. . When the blending amount of the cationic compound B is less than 100/1, the dispersion stability is poor. On the other hand, when the amount of the cationic compound B is greater than 100/30, the effect is saturated.

Vapor phase silica is also called fumed silica, and is generally made by flame hydrolysis. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state.
Mesoporous silica is a porous silica material having an average pore diameter of 1.5 to 100 nm. In addition, mesoporous silica into which aluminum, titanium, vanadium, boron, manganese atoms or the like are introduced can also be used. The physical properties of the porous body are not particularly limited, but the BET specific surface area (nitrogen adsorption specific surface area) is preferably 200 to 1500 m ² / g, and the pore volume is preferably 0.5 to 4 cc / g. The method for synthesizing mesoporous silica is not particularly limited, but is described in US Pat. No. 3,556,725, a method for synthesizing a quaternary ammonium salt containing a long-chain alkyl with a silica alkoxide as a silica source, Hydrothermal synthesis method using amorphous silica powder or alkaline silicate aqueous solution described in JP-T-5-503499 as a silica source, quaternary ammonium salt having a long chain alkyl group, or phosphonium salt as a template, A method of synthesizing a layered silicate such as kanemite as a silica source described in JP-A-4-238810, etc. by an ion exchange method using a long-chain alkylammonium cation as a template, and further dodecylamine, hexadecylamine Amines such as nonionic surfactants As a template, a method for synthesizing a silica source and water glass or the like by using an active silica obtained by ion exchange and the like. Examples of the method for removing the template from the nanoporous silica precursor include a method of baking at a high temperature and a method of extracting with an organic solvent.
After adding alkali to the colloidally dispersed silica seed solution, a silica fine particle is grown by adding a small amount of at least one feed solution selected from active silicic acid aqueous solution and alkoxysilane to the seed solution. The secondary silica dispersion can be obtained by a method described in JP-A-2001-354408.

Alumina used in the present invention is generally called crystalline alumina oxide having crystallinity. In general, alumina oxide having χ, κ, γ, δ, θ, η, ρ, pseudo γ, and α crystals can be mentioned.
In the present invention, gas phase method alumina oxide and alumina oxide having γ, δ, and θ crystals are preferably selected from the viewpoint of gloss and ink absorbability. Vapor phase alumina oxide (fumed alumina) having a sharp particle size distribution and particularly excellent film formability is most preferred. Vapor phase alumina is alumina formed by high temperature hydrolysis of gaseous aluminum trichloride, resulting in the formation of high purity alumina particles. The primary particle size of these particles is nano-order, and shows a very narrow particle size distribution (size distribution). Such vapor phase alumina oxide has a cationic surface charge. The use of vapor phase alumina in ink jet coating is shown, for example, in US Pat. No. 5,171,626.
The alumina hydrate used in the present invention is not particularly limited, but boehmite or pseudoboehmite is preferably selected from the viewpoint of ink absorbability and film formability. The method for producing alumina hydrate includes, for example, a method of hydrolyzing aluminum isopropoxide with water (BE Yoldas, amer. Ceram. Soc. Bull., 54, 289 (1975), etc.) and aluminum alkoxide. And a method of decomposing (Japanese Patent Laid-Open No. 06-064918).

  An ultrafine pigment having an average particle diameter of 0.5 μm or less selected from silica-cationic compound B aggregate fine particles, alumina aggregate fine particles, and alumina hydrate aggregate fine particles has an average primary particle diameter of 0.003 to 0.001. It is preferable that 04 μm primary particles are aggregated. In order to easily fix the dye or pigment in the ink to the outermost layer and to obtain the ink absorption rate, image density, and gloss, primary particles having an average primary particle diameter of 0.005 to 0.020 μm aggregate. A pigment having an average particle diameter of 0.01 to 0.3 μm is more preferable. More preferably, the pigment has an average particle diameter of 0.02 to 0.2 μm formed by agglomerating primary particles having an average primary particle diameter of 0.007 to 0.013 μm.

  In general, dyes and pigments in inks are anionic, and in order to fix the dyes and pigments, ultrafine aggregate pigments selected from aggregate particles of silica-cationic compound B, alumina, and alumina hydrate In addition, a cationizable compound may be added.

  A dispersion obtained by mixing / dispersing the cationic compound A and an aggregate pigment having an average particle diameter of 1 μm or more is used as an aggregate fine particle of silica-cationic compound B, alumina aggregate fine particle, alumina hydrate aggregate fine particle. The method of adding / dispersing to a slurry containing at least one ultrafine pigment having an average particle diameter of 0.5 μm or less selected from is not particularly limited, but when aggregation or thickening does not occur at the time of addition, There is no problem if it is lightly dispersed so as to be uniform, but if aggregation or thickening occurs after addition, it is more effective to disperse strongly. If the main components of the cation compound A and the cation compound B are the same, aggregation and viscosity increase hardly occur at the time of addition, and a uniform dispersion can be easily obtained.

(binder)
A dispersion obtained by mixing / dispersing the cationic compound A and an aggregate pigment having an average particle diameter of 1 μm or more is used as an aggregate fine particle of silica-cationic compound B, alumina aggregate fine particle, alumina hydrate aggregate fine particle. Can be used as a coating liquid for an inkjet recording layer by adding at least a binder to a dispersion obtained by adding / dispersing to a slurry containing at least one ultrafine pigment having an average particle size of 0.5 μm or less selected from It is.
A conventionally well-known thing is mentioned as a binder. For example, polyvinyl alcohol, polyvinylpyrrolidone, casein, soy protein, synthetic proteins, starch, carboxymethylcellulose, cellulose derivatives such as methylcellulose, polymer latex (emulsion type, solvent type, solventless type), water dispersion of synthetic resin emulsion, etc. Adhesives, temperature sensitive polymers and the like. From the viewpoint of adhesiveness to the pigment, polyvinyl alcohol is preferably the main component. In addition, polyvinyl alcohol having a polymerization degree of 3000 or more is preferable from the viewpoint of ink absorbability and crack control, and polyvinyl alcohol having a polymerization degree of 3500 or more and a saponification degree of 95% or more is more preferable. Polyvinyl alcohol having a polymerization degree of 4000 or more and a saponification degree of 97% or more is most preferable. Two or more binders may be used in combination to improve paint suitability and ink absorbability.

  Various auxiliary agents such as dispersants, thickeners, antifoaming agents, colorants, antistatic agents, preservatives and the like used in the production of general coated paper are appropriately added to the coating liquid.

(Pigment / Binder ratio (PB ratio))
When an ink jet recording layer is provided by applying the above coating liquid, there is no problem if the PB ratio is in the range of 3 to 10, and a range of 4 to 8 is preferable from the balance of ink absorbability and coating strength. The range of 4-7 is more preferable. If the PB ratio is less than 3, the ink absorption rate cannot be controlled, and beading may occur. If the PB ratio exceeds 10, the strength of the coating film is remarkably lowered and the practicality is lost.

The coating amount is not particularly limited, but is adjusted to about ² to 40 g / m ² , preferably 3 to 20 g / m ² . If it is less than 2 g / m ^2, the fixing power of dyes and pigments as color materials in the ink is insufficient, and if it exceeds 40 g / m ² , the effect is saturated.

In the case of using polyvinyl alcohol as a binder, a method of adding a compound having crosslinkability with polyvinyl alcohol and gelling the coating film is effective for the purpose of improving film formability (cracking control). The content of the compound having crosslinkability with polyvinyl alcohol is 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, more preferably 0.05 to 1 part by mass with respect to 100 parts by mass of polyvinyl alcohol. It is. When the amount is less than 0.001 part by mass, it is difficult to obtain a crosslinking effect. When the amount exceeds 10 parts by mass, the coating film becomes too hard and the coating layer may be easily broken.
It is preferable to use a compound having a crosslinking property with polyvinyl alcohol as appropriate. The addition method of the compound having crosslinkability is not particularly limited. For example, a method of directly adding to the coating, a method of adding or coating in advance on a support or another coating layer, and then coating with the coating of the present invention. Examples thereof include a method or a method of coating and impregnating a compound solution having crosslinkability before the coating layer exhibits a decreasing rate of drying.
Compounds having crosslinkability with polyvinyl alcohol include, for example, aldehyde-based crosslinking agents such as glyoxal, epoxy-based crosslinking agents such as ethylene glycol diglycidyl ether,
Examples thereof include vinyl-based crosslinking agents such as bisvinylsulfonylmethyl ether, and boron-containing compounds such as aluminum alum, boric acid and borax. In the present invention, a boron-containing compound having an excellent hardening effect is particularly preferable, and among these, borax is more preferable.

(Support)
There are no particular restrictions on the type, shape, dimensions, and the like of the support used in the ink jet recording material of the present invention, and the support may be formed from any of the ink solvent absorptive and non-absorptive supports. Examples of the absorbent support include high-quality paper, medium-quality paper, coated paper, art paper, and cast-coated paper. Examples of the non-absorbent support include plastic films such as polyethylene terephthalate, polyvinyl chloride, polycarbonate, polyethylene, and polypropylene, synthetic paper, white film, non-absorbent resin-coated paper (so-called RC paper), and the like. As the non-absorbing resin, a resin mainly composed of polyethylene, polypropylene, cellulose diacetate, or a mixture thereof can be used. Since polyethylene has good adhesion to the paper substrate, polyethylene is particularly preferable. It is preferable to use it.

When a non-absorbing support is used as the support, an adhesion treatment or an adhesion treatment is performed in advance for the purpose of improving the adhesion between the substrate and the ink receiving layer on the surface of the substrate where the ink jet recording layer is formed. Also good. In particular, when RC paper is used as the non-absorbent support, it is preferable to subject the surface of the resin coating layer to corona discharge treatment or to provide an undercoat layer made of gelatin or polyvinyl alcohol.
It is also possible to perform processing such as transportability improvement processing, antistatic processing, and antiblocking processing on the back surface of the support. The back surface treatment may be a chemical treatment such as an antistatic agent or an antiblocking agent, or may be appropriately provided by providing a coating layer mainly composed of a pigment or a coating layer mainly composed of a water-soluble resin. Other configurations may be added.

  The smoothness of the support is not particularly limited, but in order to obtain a highly glossy and highly smooth surface, the Beck smoothness is preferably 300 seconds (Oken type, J. TAPPI No. 5) or more. Further, the opacity of the substrate is not particularly limited, but in order to obtain a silver salt photographic-like appearance (particularly visual whiteness), the opacity (JIS P8138) is 85% or more. Preferably, it is 93% or more.

(Recording layer)
The recording layer coated with the coating liquid obtained by the production method of the present invention as a main component is preferably the outermost layer.
In addition to the recording layer coated with the coating liquid of the present invention as the main component, other coating layers can be provided in order to improve absorbability and adhesion to the support. The other coating layer may be a single layer or a multilayer.

  Other pigments used in the coating layer include silica, colloidal silica, alumina, alumina hydrate, alumina silicate, kaolin, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum hydroxide, calcium carbonate, satin White or aluminum silicate, smectite, zeolite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene-based plastic pigment, urea resin-based plastic pigment, etc. Mix and use.

  Examples of the binder include water-soluble resin binders such as polyvinyl alcohol and water-insoluble synthetic resin latexes.

  If the PB ratio of the other coating layer is in the range of 1 to 8, there is no problem, the range of 2 to 7 is preferable, and the range of 2.5 to 6.5 is more preferable from the balance of solvent absorption and coating strength. . If the PB ratio is less than 1, the solvent absorption rate is slow, and if it exceeds 8, the strength of the coating film may be significantly reduced.

The coating amount of the other coating layer is not particularly limited, but is adjusted to about ² to 30 g / m ² , preferably 5 to 20 g / m ² .

  Various auxiliary agents such as dispersants, thickeners, antifoaming agents, colorants, antistatic agents, preservatives and the like used in the production of general coated paper are appropriately added to the other coating layers. Further, since a very small amount of dye is fixed as the solvent is absorbed, a cationic compound may be added and used for fixing the dye.

The recording material of the present invention is particularly preferably used as an ink jet recording material in place of photographs, illustrations, print proofing and printing paper. In order to use an ink jet recording medium instead of printing proofreading or printing paper, the whiteness of the white surface of the recording medium measured by JIS P8148 is 80 to 90%, the perceptual chromaticity index a * is −1 to 2, and the perceptual chromaticity It is desirable that the index b * is adjusted to −3 to 1.5. The most preferable range is whiteness of 83 to 88%, perceptual chromaticity index a * of 0 to 1.5, and perceptual chromaticity index b * of −2.5 to −1. In order to satisfy the white paper hue, a colorant is contained in at least one coating layer. As the colorant, a color pigment is preferably used from the viewpoint of storage stability.
Examples of coloring pigments include water-soluble azo pigments, water-insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, titanium black, titanium yellow, ultramarine blue, cobalt blue, carbon black, iron black, zinc oxide, participating cobalt, and aluminum hydroxide. However, it is not limited to this. Moreover, a white pigment can also be used for the purpose of improving the whiteness and adjusting the color tone. For example, publicly known materials such as clay, calcined clay, calcium carbonate, magnesium carbonate, titanium dioxide, zeolite, kaolin, calcined kaolin, barium sulfate, inorganic pigments such as magnesium silicate, and organic pigments such as polystyrene resin and polycarbonate resin It is done.

The hue is often adjusted with only two types of color pigments, but if at least three types are selected from blue, violet, red, and yellow, a hue close to that of printing paper can be easily obtained.
Although there is no problem even if the coloring pigment for hue adjustment is blended in the coating liquid of the present invention, since the recording layer obtained with the coating liquid of the present invention has transparency, it is colored for hue adjustment from the viewpoint of storage stability. In addition to the coating liquid of the present invention, for example, the pigment is desirably contained in the other coating layer or support described above.

  It is also possible to provide a back layer for the purpose of improving curling and transportability. The back layer is more easily curled when the main component is a hydrophilic resin (eg, polyvinyl alcohol, starch, casein, gelatin, etc.).

  In order to increase gloss, it is possible to use a so-called casting method, which is obtained by pressing and drying a heated mirror drum while the outermost layer is in a wet state.

(Coating device and coating method)
As a coating apparatus for obtaining a recording layer and other coating layers containing the coating liquid of the present invention as a main component, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip Various known coating apparatuses such as a coater, a curtain coater, and a die coater can be used. Of course, when two or more layers are applied, it is preferable to apply by wet on wet, which is a method of applying the upper layer on the lower layer while the lower layer is not dried.

(Calendar processing)
After coating at least one of the recording layer containing the coating liquid of the present invention as a main component and other coating layers, smoothing with a calendar improves the surface roughness of the ink jet recording body, and the glossiness of appearance. It is possible to improve feeling and smoothness. The calendar pressure is preferably 30 to 250 kg / cm. If the calender pressure is lower than 30 kg / cm, the smoothing effect cannot be obtained. If the calender pressure is higher than 250 kg / cm, the coating layer is excessively crushed and the ink absorbability is inhibited. More preferably, it is 50-180 kg / cm.
(Average particle size)
The particle diameter of the aggregate pigment referred to in the present invention is a number average particle diameter, and a dispersion immediately after stirring and dispersing a 5% dispersion with a homomixer at 2000 rpm for 30 minutes is used as a sample, and an electron microscope (SEM and TEM). Taken by taking an electron microscope photograph of 10,000 to 400,000 times, and measuring and averaging the diameter of the secondary particles in a 5 cm square (see “Fine Particles Handbook”, Asakura Shoten, p52, 1991) ).

(ink)
As the ink used in the ink jet recording method of the present invention, a dye (dye, pigment) for forming an image and a liquid medium for dissolving or dispersing the dye are essential components, and various dispersants are used as necessary. It is adjusted by adding a surfactant, a viscosity modifier, a specific resistance modifier, a pH adjuster, a fungicide, and the like.

As the colorant used in the ink, there are a dye system and a pigment system. For example, there are various water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes, edible dyes, disperse dyes, and oil-based dyes in the dye system. Examples thereof include carbon black surface-treated with an agent, organic pigments, and the like, and conventionally known ones can be used without particular limitation. The content of the dye or pigment is determined depending on the kind of the solvent component of the ink, the characteristics required for the ink, etc., but the ink used in the present invention is also similar to that in the conventional ink. There is no particular problem with blending, that is, use of about 0.1 to 20% by mass.

Examples of the solvent for the ink used in the present invention include water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol. Alkyl alcohols, ketones such as acetone and diacetone alcohol, or polyalkylene glycols such as polyethylene glycol and polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, tetraethylene glycol, thiodi Alkylene glycols having 2 to 6 alkylene groups such as glycol, hexylene glycol and diethylene glycol, amides such as dimethylformamide, tetrahydrofuran, etc. Ethers, glycerine, ethylene glycol methyl ether, diethylene glycol methyl (ethyl) ether, trimethylol propane, 1
, 2-hexanediol, lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether, and pyrrolidones such as N-methyl-2-pyrrolidone. Among these, the pigment ink containing 1,2-hexanediol and glycerin as the water-soluble organic solvent in the pigment ink, and the total of both is 80% by mass or more of the water-soluble solvent, and the recording material of the present invention. A combination is preferable in terms of scratch resistance.

  The present invention will be specifically described by the following examples. However, these examples do not limit the scope of the present invention. Moreover, "part" and "%" in an Example and a comparative example show the mass part and mass% of solid content except water, unless otherwise indicated.

[Silica dispersion a]
Cationic resin diallylamine-based polymer (manufactured by Nittobo Co., Ltd., trade name: PAS-H-10L, molecular weight: about 200,000, quaternary ammonium) 1% aqueous solution 1000 g of wet powder silica with a particle size of 6 μm with stirring 110 g (trade name: Fine Seal X-60, manufactured by Tokuyama Co., Ltd.) was gradually added and dispersed with a homomixer (rotation speed: 1500 rpm) for about 30 minutes.

[Silica dispersion b]
The cationic resin is changed to polyvinylamine copolymer ammonium hydrochloride having a polymer unit having a 5-membered ring amidine structure (product name: Himax SC-700M, molecular weight: about 30,000, primary amine). A dispersion was prepared in the same manner as [Silica dispersion a] except that.

[Silica dispersion c]
A dispersion was prepared in the same manner as [Silica dispersion a] except that 6 μm wet powder silica was changed to 3 μm wet powder silica (trade name: Fine Seal X-30, manufactured by Tokuyama Corporation).

[Slurry A of inorganic pigment-cationic resin composite fine particles]
A step of dispersing and pulverizing commercially available fumed silica (manufactured by Tokuyama Corporation, trademark: Leolosil QS-30, specific surface area 300 m ² / g, average primary particle size: about 9 nm) in water with a homomixer, and then using a nanomizer The combination with the step of pulverizing and dispersing was repeated, and the obtained dispersion was classified to prepare a 10% dispersion of silica fine particles having an average secondary particle diameter of 80 nm. 11 parts of a polyvinylamine copolymer ammonium hydrochloride having a five-membered ring amidine structure as a cationic resin (trade name: Himax SC-700, molecular weight: 300,000) having a five-membered ring amidine structure as a cationic resin in 100 parts of silica solid content of this dispersion. (Solid content conversion) was mixed to obtain a thickened aggregate dispersion. This thickened aggregate dispersion is again dispersed with a homomixer, and pulverization and dispersion treatment using a nanomizer is repeated to obtain slurry A (solid content of inorganic pigment-cationic resin composite fine particles having an average secondary particle size of 100 nm. Concentration: 11%) was prepared.

[Slurry B of inorganic pigment-cationic resin composite fine particles]
Except for changing the cationic resin to polyvinylamine copolymer ammonium hydrochloride having a 5-membered ring amidine structure (product name: Himax SC-700M, molecular weight: about 30,000, primary amine), Slurry B was prepared in the same manner as for the inorganic pigment-cationic resin composite fine particle aqueous slurry A].

[Slurry C of inorganic pigment-cationic resin composite fine particles]
Commercially available fumed silica (trade name: Leoro Seal QS-30, specific surface area 300 m ² / g, average primary particle size: about 9 nm) 100 parts, 3 μm wet powder silica (trade name: Fine Seal, manufactured by Tokuyama Corporation) X-30) Repeating a combination of a step of dispersing and pulverizing 4 parts in water with a homomixer, and then a step of pulverizing and dispersing using a nanomizer, classifying the obtained dispersion, and obtaining average secondary particles A 10% dispersion of silica fine particles having a diameter of 80 nm was prepared. 11 parts of a polyvinylamine copolymer ammonium hydrochloride having a five-membered ring amidine structure as a cationic resin (trade name: Himax SC-700, molecular weight: 300,000) having a five-membered ring amidine structure as a cationic resin in 100 parts of silica solid content of this dispersion. (Solid content conversion) was mixed to obtain a thickened aggregate dispersion. This thickened aggregate dispersion is again dispersed with a homomixer and further subjected to pulverization and dispersion treatment using a nanomizer to repeat slurry C (solid content) of inorganic pigment-cationic resin composite fine particles having an average secondary particle diameter of 100 nm. Concentration: 11%) was prepared.

Example 1
4 parts of [silica dispersion a] are added to and dispersed in 100 parts of pseudoboehmite sol (manufactured by Catalyst Kasei Co., Ltd., trade name: AS-3, particle size: about 0.5 μm), and further, the degree of polymerization is 4000 and the degree of saponification A 10% coating solution was prepared by adding and mixing 12 parts of 98% polyvinyl alcohol.
On a support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ), the coating amount of 4% borax aqueous solution is 0.15 g / m ² , and the coating amount of the paint is 15 g / m ² . In this manner, the ink jet recording material was produced by applying and drying under the conditions of Wet on Wet (a method of applying the upper layer on the lower layer while the lower layer is not dried when two or more layers are applied).

Example 2
Inkjet recording material as in Example 1, except that pseudoboehmite sol was changed to fumed alumina sol (trade name: PG-003, manufactured by CABOT, Inc.) having a particle size of 0.2 μm, and the amount of polyvinyl alcohol was changed to 9 parts. Was made.

Example 3
An ink jet recording material was prepared in the same manner as in Example 1 except that the pseudo boehmite sol was changed to [Slurry A of inorganic pigment-cationic resin composite fine particles] and the blending amount of polyvinyl alcohol was changed to 17 parts.

Example 4
An ink jet recording material was produced in the same manner as in Example 3 except that [silica dispersion a] was changed to [silica dispersion b].

Example 5
An ink jet recording material was produced in the same manner as in Example 3 except that [silica dispersion a] was changed to [silica dispersion c].

Example 6
An ink jet recording material was produced in the same manner as in Example 5, except that [Slurry A of inorganic pigment-cationic resin composite fine particles] was changed to [Slurry B of inorganic pigment-cationic resin composite fine particles].

Example 7
40 parts of an acrylic emulsion latex was mixed with 100 parts of a wet gel silica having a particle diameter of 0.3 μm (trade name: 703A, manufactured by Grace) to prepare a 20% paint.
A support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ) was coated and dried so that the coating amount of the dispersion became 10 g / m ² to obtain a first coating layer. The coating amount of the 4% borax aqueous solution on the first coating layer is 0.15 g / m ² and the coating amount of the paint of Example 6 is 10 g / m ² under the conditions of Wet on Wet. Coating and drying were performed to prepare an ink jet recording material.

Example 8
In Example 7, 100 parts of wet gel method silica having a particle size of 0.3 μm in the first coating layer was mixed with 50 parts of wet gel method silica having a particle size of 0.3 μm, kaolin (trade name: Ultra White, manufactured by Engelhard) 90, an average particle diameter of 0.5 μm, an oil absorption of 46 ml / 100 g, and a specific surface area of 14 m ² / g) An ink jet recording material was prepared in the same manner as in Example 7 except that the mixture was changed to 50 parts.

Example 9
In Example 8, with respect to 100 parts of the pigment of the first coating layer, 0.02 part of a blue color pigment (manufactured by Toyo Ink, trade name: EMT Blue DS18), a violet color pigment (manufactured by Toyo Ink, An ink jet recording material was prepared in the same manner as in Example 8 except that 0.04 part of a trade name: EMT violet BE) and 0.02 part of a yellow color pigment (manufactured by Toyo Ink Co., Ltd., trade name: EMT Yellow 5G) were blended. did.
(Comparative example)

Comparative Example 1
An ink jet recording material was produced in the same manner as in Example 1 except that [silica dispersion a] was removed.

Comparative Example 2
An ink jet recording material was produced in the same manner as in Example 2 except that [silica dispersion a] was removed.

Comparative Example 3
An ink jet recording material was prepared in the same manner as in Example 3 except that [silica dispersion a] was removed.

Comparative Example 4
An ink jet recording material was produced in the same manner as in Example 3 except that [Slurry A of inorganic pigment-cationic resin composite fine particles] was changed to [Slurry C of inorganic pigment-cationic resin composite fine particles].

Comparative Example 5
4 parts of wet powder silica (trade name: Fine Seal X-30, manufactured by Tokuyama Co., Ltd.) are added to 100 parts of pseudo boehmite sol (trade name: AS-3, particle size: about 0.5 μm), Dispersion was performed (homomixer, 1500 rpm, 30 minutes), and 12 parts of polyvinyl alcohol having a polymerization degree of 4000 and a saponification degree of 98% was added and mixed to prepare a 10% coating solution.
On a support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ), the coating amount of 4% borax aqueous solution is 0.15 g / m ² , and the coating amount of the paint is 15 g / m ² . In this manner, the ink jet recording material was produced by applying and drying under the conditions of Wet on Wet (a method of applying the upper layer on the lower layer while the lower layer is not dried when two or more layers are applied).

Comparative Example 6
4 parts of wet powdered silica (trade name: Fine Seal X-30, manufactured by Tokuyama Co., Ltd.) are added to 100 parts of fumed alumina sol (trade name: PG-003, manufactured by CABOT Co., Ltd.) having a particle size of 0.2 μm, and dispersed (homo Mixer, 1500 rpm, 30 minutes), and 12 parts of polyvinyl alcohol having a polymerization degree of 4000 and a saponification degree of 98% were added and mixed to prepare a 10% coating solution.
On a support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ), the coating amount of 4% borax aqueous solution is 0.15 g / m ² , and the coating amount of the paint is 15 g / m ² . In this manner, the ink jet recording material was produced by applying and drying under the conditions of Wet on Wet (a method of applying the upper layer on the lower layer while the lower layer is not dried when two or more layers are applied).

Comparative Example 7
[Slurry A of inorganic pigment-cationic resin composite fine particles] 4 parts of wet powder silica (trade name: Fine Seal X-30, manufactured by Tokuyama Co., Ltd.) are added to 100 parts, and dispersed (homomixer, 1500 rpm, 30 minutes). Further, 12 parts of polyvinyl alcohol having a polymerization degree of 4000 and a saponification degree of 98% was added and mixed to prepare a 10% coating solution.
On a support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ), the coating amount of 4% borax aqueous solution is 0.15 g / m ² , and the coating amount of the coating solution is 15 g / m ^2. The ink-jet recording material was prepared by applying and drying under the conditions of Wet on Wet (when two or more layers are applied, a method of applying the upper layer onto the lower layer while the lower layer is not dried).

Comparative Example 8
Cationic resin diallylamine-based polymer (manufactured by Nittobo Co., Ltd., trade name: PAS-H-10L, molecular weight: about 200,000, quaternary ammonium) 850 g of 3% aqueous solution, 3 μm wet silica (manufactured by Tokuyama Co., trade name: Fine Seal X-30) 150 g was added and dispersed, and 30 parts of polyvinyl alcohol having a polymerization degree of 1800 and a saponification degree of 98% was added and mixed to prepare a 14% coating solution.
A support (manufactured by Oji Paper Co., Ltd., marshmallow 104.7 g / m ² ) was coated and dried so that the coating amount of the coating solution was 14 g / m ² to prepare an ink jet recording material.

[Evaluation methods]
About Examples 1-9 and Comparative Examples 1-8, surface smoothness of the obtained ink jet recording materials, ink absorbability, image quality of recorded images of dye and pigment ink, scratch resistance of pigment ink, gloss of blank paper and pigment ink The gloss difference on the printed part was evaluated by the following method.
[Printer]
Dye inkjet printer: manufactured by Epson, model: PM-G820, printing in photo paper clean mode.
Pigment inkjet printer: manufactured by Epson Corporation, model: PX-6000, PX-MC photographic paper (thick and fine gloss) printing.

(Smoothness of blank paper)
The tested recording medium was judged visually and textured and evaluated according to the following three levels.
○: The surface is not rough and smooth.
Δ: A rough feeling is seen on the surface, but it is smooth and has no practical problem.
X: The surface is rough and inferior in smoothness.

(Ink absorption)
The sample recording medium was subjected to green and blue solid printing with the above two types of printers, and the ink absorptivity was visually observed and evaluated by the following methods.
○: The ink absorption speed is fast, and there is no ink overflow or beading.
Δ: Some beading is recognized, but there is no practical problem.
×: Ink overflow and beading.

(Recorded image quality)
The black solid print portion was measured with a Macbeth reflection densitometer (Macbeth RD-920), and the print density was measured.

(Friction of pigment ink)
The printed portion (black solid) of the pigment ink was rubbed with a cotton swab immediately after printing and evaluated by the following method.
○: Ink is not taken out and there is no problem Δ: Ink is taken out slightly, but there is no problem in practical use ×: Ink is taken out, practically problematic level

(Gloss difference between white paper gloss and pigment ink printing)
The gloss of the pigment ink printing part (solid printing of each color) and the blank paper part was visually observed and evaluated by the following method.
○: Level where there is almost no gloss difference Δ: Level where gloss difference is observed and anxious ×: Large gloss difference

[Evaluation Method 2]
For Example 9, printed matter (ISO-400 image, “high-definition color digital standard image data ISO / JIS-SCID”, p13, image name: fruit and basket) obtained with a white paper and pigment inkjet printer, and for printing Evaluation was made using coated paper A2 gloss coated paper (Oji Paper Co., Ltd., OK top coat + 127.9 g / m ² ) and its offset print (the above image). The results are summarized in Table 2.
(Blank hue)
Table 2 shows the result of visual comparison with the blank hue of A2 gloss coated paper.
(Whiteness, perceived chromaticity index)
The whiteness of the surface of the test inkjet recording material was measured by the method of JIS P8148, and the perceptual chromaticity index a * was measured by the method of JIS P8722.

As is apparent from Table 1, the ink jet recording material obtained by applying the coating liquid obtained by the production method of the present invention as a paint has a blank surface smoothness, ink absorbency, dye and pigment ink recording. This is an ink jet recording material that has excellent image quality and pigment ink scuff resistance, and has a small difference in gloss between the white paper gloss and the pigment ink print area.
Further, as apparent from Table 2, the ink jet recording material of the present invention has a good appearance and has the same whiteness and color tone as that of the print coated paper by blending the color pigment, and the printing proof paper and the general printing It is also excellent as an inkjet paper that replaces paper.

The ink jet recording material obtained by the production method of the present invention has suitability for dyes and pigments, good ink absorbability, excellent surface smoothness of the recording material, and particularly has a small difference in glossiness between the printed portion of white paper and pigment ink. Therefore, an ink jet recording material useful for photography and printing proofing can be obtained.

Claims (9)

  In the method for producing a coating liquid for an ink jet recording layer containing a pigment and a binder, a dispersion obtained by mixing / dispersing the cationic compound A and an aggregate pigment having an average particle diameter of 1 μm or more is treated with a silica-cationic compound. It is obtained by adding / dispersing to a slurry containing at least one ultrafine pigment having an average particle size of 0.5 μm or less selected from B aggregate fine particles, alumina aggregate fine particles, and alumina hydrate aggregate fine particles. The manufacturing method of the coating liquid for inkjet recording layers.   In the silica-cationic compound B aggregate fine particle slurry, silica-cationic compound B aggregate particles obtained by mixing dry silica and cationic compound B in advance are in the range of 0.01 to 0.5 μm. The method for producing a coating liquid for an ink jet recording layer according to claim 1, wherein the liquid is pulverized and dispersed.   The method for producing a coating liquid for an ink jet recording layer according to claim 1, wherein the aggregate pigment is wet silica.   The main component of the cationic compound A and the cationic compound B has the same structural formula, The manufacturing method of the coating liquid for inkjet recording layers in any one of Claims 1-3.   The said aggregate pigment is a manufacturing method of the coating liquid for inkjet recording layers in any one of Claims 1-4 containing 0.5-15 mass% with respect to the total pigment mass.   The method for producing a coating liquid for an ink jet recording layer according to any one of claims 1 to 5, wherein the binder is mainly composed of polyvinyl alcohol having a polymerization degree of 3000 or more.   A method for producing an ink jet recording material, comprising applying the coating liquid according to claim 1 on a support and providing an ink jet recording layer.   An ink jet recording material, wherein an ink jet recording layer is provided by coating the coating liquid according to claim 1 on a support. An ink jet recording material comprising at least one recording layer, wherein the outermost layer is coated by using the coating liquid according to claim 1.