JP2009196190A - Inkjet recording body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glossy inkjet recording body which is excellent, in details, in scratch resistance when feeding printer paper, ink absorbency, glossiness, and productivity, and also, is excellent in inkjet recording property regarding the glossy inkjet recording body. <P>SOLUTION: This inkjet recording body is constituted by laminating an ink fixing layer and a glossiness developing layer in order on a supporting body. In the inkjet recording body, the ink fixing layer contains a pigment of which the average particle diameter is 0.01 to 1 μm. The glossiness developing layer contains a colloidal particle and a paraffin based wax of which the average particle diameter is 0.02 to 0.5 μm for the inkjet recording body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glossy ink jet recording body, and more particularly to a glossy ink jet recording body excellent in scratch resistance, ink absorbability, glossiness, and productivity when fed to a printer and excellent in ink jet recording suitability.

The ink jet recording method that forms an image by ejecting ink droplets from fine nozzles and depositing them on the surface of the recording medium has low noise during recording, easy formation of full-color images, and high speed It is widely used in terminal printers, facsimiles, plotters, form printing, and the like due to the fact that recording is possible and the recording cost is lower than other printing apparatuses.
In recent years, inkjet printers have been improved in definition and speed, and the spread to general home users has been increasing for the purpose of outputting captured images using a digital camera or the like.
Among them, the inkjet recording medium has excellent gloss on the surface of the inkjet recording body in order to bring the quality of the recorded image output from the photographed image closer to that of a silver salt photograph, and the color development and depth of the recorded image. High image quality is required. There is also a demand for ink absorptivity corresponding to the speeding up of ink jet printers.

Furthermore, with the spread to general household users, it is required to reduce the area required for printer installation for efficient installation. As one of the solutions, depending on the model, a paper feed tray below the printer is required. In addition, a paper feeding method is employed in which after a recording body having a printing surface set downward is picked up, the recording body is inverted inside the printer so that the printing surface faces upward and then printing is performed. This paper feeding method is sometimes referred to as C-type paper feeding in which the state of the recording medium rotating inside the printer is compared to the letter “C” in the alphabet, and a conventional paper feeding method (C-type paper feeding from the back of the printer). On the other hand, this is called J-type paper feed.).

  In C-type paper feeding, since the recording medium is rotated in a narrow paper feeding path inside the printer, there is a tendency that the printing surface is rubbed and scratched by the paper feeding path of the printer. In particular, when the ink jet recording material has high gloss, the scratches are very conspicuous, and it is very important to solve this problem in order to obtain a recorded image close to the quality of a silver salt photograph. is there.

The following proposals have been made to meet the demands for these ink jet recording media in order to satisfy not only the conventional glossiness and ink absorbability, but also the printer transportability and scratch resistance at the same time. .
For example, Patent Document 1 proposes an ink jet recording material having high gloss, photo-like image quality, and good scratch resistance.
Further, in Patent Document 2, in order to obtain high smoothness and gloss, an ink receiving layer comprising a pigment and a transparent binder is provided, and the pigment and binding for imparting gloss are provided on the ink receiving layer. An ink jet recording material in which a cast gloss layer containing an agent is formed has been proposed.
Patent Documents 3 and 4 propose an ink jet recording material that not only improves gloss but also increases the strength of the coating film by containing fine pigment and synthetic polymer latex as the main components in the outermost layer. Has been.
On the other hand, examples in which paraffin wax is contained in the coating layer to provide image clarity and an inkjet recording material is proposed (Patent Documents 5 and 6), polyethylene wax is contained in the gloss layer, and gloss and printing are performed. There are also an example (Patent Document 7) that proposes an ink jet recording body that imparts image sharpness by color development and an example that reduces friction between the front and back of a paper (Patent Document 8).
JP 2003-025711 A JP 2002-248850 A Japanese Patent Laid-Open No. 7-101142 Japanese Patent Laying-Open No. 2005-041232 JP 2003-103915 A JP-A-11-58934 JP 2005-22334 A JP 2002-172853 A

In Patent Document 1, the scratch resistance of a recording material is determined by providing a protective layer containing a hydrophilic binder on a glossy recording surface and a hydrophilic binder on the surface opposite to the glossy recording surface. It is achieved by providing. This is effective when the recording medium is cut with guillotine or when transported while being loaded. However, when the C-type paper is fed, the glossy recording surface is damaged by the paper feed path of the printer. The effect of the surface on the opposite side to the recording surface having the above cannot be obtained, and the effect of preventing scratches is insufficient only by the effect of the protective layer.
In Patent Document 2, since the pigment of the ink receiving layer is as large as 2 to 15 μm, the glossiness and recording density are insufficient in view of the currently required quality.
In Patent Documents 3 and 4, the outermost synthetic polymer latex is excellent in gloss and recording density and has good cracking properties, but does not have an effect of preventing scratches on the C-type paper feed.

Patent Document 5 proposes a method of obtaining glossy paper for ink-jet recording by applying a coating liquid containing a pigment, an adhesive, and paraffin wax and then casting the coating layer. In this method, the coating layer is intended to express the effects of print quality, gloss, and releasability, and it is difficult to achieve both ink absorbability and gloss, and the paraffin wax reaches the inside of the coating layer. Therefore, the efficiency of releasability is poor, the effect of paraffin wax is insufficient, and the effect of preventing scratches is not obtained.
In the method of Patent Document 6, although the dot diameter is a perfect circle, both the glossiness and the prevention of scratches at the time of paper feeding are inadequate. In Patent Document 7, even though a high gloss can be obtained. However, it is difficult to obtain a clear image and the printed image is easily damaged. Patent Document 8 does not consider glossy type paper, and does not suggest means for improving scratches during paper feeding as in the present invention.

As described above, none of the ink jet recording materials described in the above patent documents has been able to obtain satisfactory quality in terms of scratch resistance, ink absorbability, glossiness, and productivity when feeding a printer. It is.

The present invention has been made in view of the above circumstances, and as a result of intensive studies, the present inventors use pigments that enable excellent ink absorbability and high smoothness for the ink fixing layer. This makes it possible to obtain high gloss even with a glossy layer with a relatively small amount of coating, and further reduces the drying load during gloss processing, thus greatly improving productivity and improving ink absorption. I found that it contributed. Further, the present inventors have found that the above problems can be solved by using a pigment exhibiting high gloss and a paraffinic wax excellent in releasability and scratch resistance in the gloss developing layer, and completing the present invention. It came. That is, by concentrating the colloidal particles and the paraffinic wax on the outermost layer portion, high gloss is achieved without impairing ink absorbability, and the mold release performance and scratch resistance performance are achieved. The advantages of the paraffinic wax that they have can be maximized.
The technical problem of the present invention is to provide a glossy ink jet recording material having high ink absorbability and white paper glossiness, excellent image sharpness, no damage when fed to a printer, and excellent productivity. .

(1) In an ink jet recording body in which an ink fixing layer and a gloss developing layer are sequentially laminated on a support, the ink fixing layer contains a pigment having an average particle diameter of 0.01 to 1 μm, and the gloss developing layer is a colloid. An ink jet recording material comprising a particulate particle and a paraffinic wax having an average particle diameter of 0.02 to 0.5 μm.
(2) The inkjet recording material as described in (1), wherein the glossy layer has a dry coating amount of 0.2 to 4.5 g / m ² .
(3) The inkjet recording material according to (1) or (2), wherein the gloss developing layer contains 0.1 to 50 parts by mass of paraffinic wax with respect to 100 parts by mass of colloidal particles.
(4) The gloss developing layer is a cast-finished layer, and the gloss developing layer surface has a 20-degree gloss mirror surface gloss (JIS-P8741) of 25% or more, and any one of (1) to (3) 2. An ink jet recording material according to 1.
(5) The inkjet recording material according to any one of (1) to (4), wherein the glossy layer further contains at least one adhesive selected from a water-soluble adhesive and a water-dispersible adhesive. .
(6) The ink jet recording material according to (5), wherein the water dispersible adhesive is an acrylic resin or a urethane resin.
(7) The ink jet recording material according to (5), wherein the water-soluble adhesive is polyvinyl alcohol.

  The ink jet recording material of the present invention has high ink absorbability and white paper gloss, is excellent in image sharpness, is not damaged when fed into a printer, and is excellent in productivity.

The present invention has an ink fixing layer and a gloss developing layer on at least one surface of a support, the ink fixing layer contains a pigment having an average particle size of 0.01 to 1 μm, and the gloss developing layer has colloidal particles. And an ink jet recording material containing paraffinic wax having an average particle size of 0.02 to 0.5 μm.
In the present invention, a layer similar to the above may be provided on the other surface side of the substrate. In this case, the effect of the present invention can be exhibited on both sides of the ink jet recording body.

<Base material>
Although the base material used for the inkjet recording body of this Embodiment is not specifically limited, It is using the paper base material which is a gas-permeable base material, the resin film or sheet material which has gas permeability. preferable.
In particular, it is preferable to use a paper base material from the viewpoints of excellent air permeability, ease of handling as a recording medium, and ease of disposal.
As the paper substrate, a known paper substrate that is usually used can be used as long as the effects of the present invention are not impaired. For example, fine paper, art paper, coated paper, cast coated paper, craft paper , Baryta paper, paperboard, impregnated paper, and vapor-deposited paper.
In addition, acidic paper, neutral paper, and the like used for general coated paper are also used as appropriate.

[Paper base]
The outline | summary of these paper base materials is demonstrated.
The paper base material contains wood pulp as a main component, and fillers, various auxiliaries and the like are added as necessary.
As the wood pulp, various chemical pulps, mechanical pulps, recycled pulps and the like can be used.
In particular, softwood and hardwood kraft pulp, or softwood bleached kraft pulp bleached from these kraft pulp (referred to as NBKP) and hardwood bleached kraft pulp (referred to as LBKP) are preferable.
Also, in these pulps, chlorine-free pulp that has removed the influence of chlorine in the bleaching process, such as ECF (Elemental Chlorine Free) pulp that uses chlorine compounds without using chlorine itself for pulp bleaching, and elemental chlorine in pulp bleaching It is preferable to use TCF (Total Chlorine Free) pulp or the like using a bleaching agent which is not contained at all.

These pulps can be adjusted with a beater to adjust paper strength, papermaking suitability, etc., and the beating degree (CSF: Canadian Standard Freeness) is not particularly limited, but is 250 to 550 ml (JIS). -P8121) is preferred.

As the filler added to the paper substrate, for example, light calcium carbonate, heavy calcium carbonate, calcined kaolin, synthetic zeolite, silica, titanium oxide, talc and the like are preferably used. Among these, light calcium carbonate, calcined kaolin, and synthetic zeolite are preferable because they are porous and have an excellent ability to absorb the solvent in the ink ejected from the ink jet printer. Among them, light calcium carbonate is a paper base having high whiteness. A material is obtained, and the glossiness of the ink jet recording material is also increased, which is preferable.
The filler content (ash content) in the paper substrate is preferably about 1 to 20% by mass. Within this range, smoothness, air permeability, paper strength and rigidity are balanced, and a glossy ink jet recording material excellent in balance of glossiness, image clarity and rigidity is easily obtained.

Examples of auxiliary agents added to the paper base include sizing agents, fixing agents, paper strength enhancers, cationizing agents, yield improvers, dyes, and fluorescent brighteners. Is done.
As the sizing agent, known sizing agents such as reinforced rosin and alkenyl succinic anhydride are used.
In addition, a sulfuric acid band is used as a fixing agent for this sizing agent, and starch is used as a fixing yield improving agent in combination with the sizing agent.

  The paper base material may be subjected to size press treatment. The purpose of the size press is to control the sizing degree, increase paper strength, smoothing, etc. The size press solution contains starches, polyvinyl alcohols, sizing agents, various pigments, etc., which are known and used in accordance with the respective purposes. Material is used. About 1 to 300 seconds are preferable, and the Stecchito sizing degree (JIS-P8122) of the paper substrate is more preferably 4 to 200 seconds. If the sizing degree is less than 1 second, there is a risk of operational problems such as wrinkling during coating, and if it exceeds 300 seconds, the ink absorbability may decrease, and curling and cockling after printing. (Absorption wrinkles) may be remarkably unfavorable.

Although the basic weight of a paper base material is not specifically limited, About 20-400 g / m < ² > is preferable.
10-350 seconds are preferable, as for the Oken type air permeability (JAPAN TAPPINo. 5) of a paper base material, 10-200 seconds are more preferable, and 20-100 seconds are further more preferable.
If the air permeability is less than 10 seconds, the ink receiving layer coating liquid may permeate excessively into the paper substrate, and if it exceeds 350 seconds, it may occur when press-contacting the cast drum. There is a possibility that the operability is lowered, which is not preferable.
The paper substrate is manufactured by a long net paper machine or the like, and the thickness thereof is not particularly limited, but is appropriately selected in the range of 20 μm to 500 μm depending on the application.

<Coating layer>
The glossy ink jet recording material of the present embodiment includes a single ink fixing layer provided on a base material, and a gloss developing layer provided on the ink fixing layer and forming the outermost portion of the recording material. It has two coating layers. This ink fixing layer is not limited to one layer, and two or more ink fixing layers may be provided as necessary.
When three or more coating layers are provided, one layer may be provided on the base material as an undercoat layer that absorbs the ink solvent, and an ink fixing layer may be provided thereon.

[Ink fixing layer]
This ink fixing layer is mainly composed of a pigment having an average particle diameter of 0.01 to 1 μm and an adhesive for holding the pigment, and a cationic ink for better fixing the dye and pigment in the ink. It preferably contains a fixing agent.

(Pigment)
As the pigment of the ink fixing layer, a fine secondary pigment having an average particle diameter of 0.01 to 1 μm is used. It is preferably selected from silica, alumina, and alumina hydrate. Among these pigments, silica is particularly preferable, and dry silica is more preferable.
Further, the silica is preferably silica-cationic compound aggregate particles obtained by mixing silica and a cationic compound, and the aggregate produced by mixing is pulverized and dispersed to have an average particle diameter of 0.01 to 1 μm. Used as aggregate fine particles. The cationic compound and silica-cationic compound aggregate particles act as an ink fixing agent, and will be described in detail in the section of the ink fixing agent.
The aggregate fine particles most preferably have an average particle size in the range of 0.03 to 0.5 μm. If the particle diameter is less than 0.01 μm, the ink absorbability may be lowered. If the particle diameter is more than 1 μm, the transparency of the coating film is inferior, the print density may be significantly lowered, and the smoothness is also impaired. . Furthermore, in order to obtain high glossiness, it is necessary to increase the coating amount of the upper glossy expression layer, and as a result, there is a concern that ink absorbability is lowered and productivity is lowered.

This average particle size is a particle size that was first observed with an electron microscope (SEM and TEM) after adjusting 200 g of a 3% silica dispersion and subsequently stirring and dispersing with a commercially available homomixer at 1000 rpm for 30 minutes. The Martin diameter of silica dispersed particles was measured and averaged (see “Fine Particle Handbook”, Asakura Shoten, p. 52, 1991).
As a result of measurement by the present inventors, when the silica is in a slurry state, the particle diameter varies greatly depending on the agglomeration state of the silica.

  In the ink fixing layer, a known pigment used for ordinary recording paper can be used in combination with the above pigment having an average particle diameter of 0.01 to 1 μm within a range not impairing the effects of the present invention. These pigments include kaolin (containing clay), calcium carbonate, titanium oxide, zinc oxide, amorphous silica (containing colloidal silica), aluminum oxide, zeolite, sepiolite, smectite, synthetic smectite, magnesium silicate, magnesium carbonate, oxidation Magnesium, diatomaceous earth, styrene plastic pigment, hydrotalcite, urea resin plastic pigment, benzoguanamine plastic pigment and the like can be mentioned, and these can be used alone or in combination.

(adhesive)
As the adhesive, a water-dispersed adhesive or a water-soluble adhesive can be used alone or in combination. Examples of water-dispersed adhesives include styrene-butadiene copolymer resins, methyl methacrylate-butadiene copolymer conjugated diene resins, acrylic resins, and vinyl resins such as ethylene-vinyl acetate copolymer resins. . Among these, acrylic resins and urethane resins are particularly preferable in terms of ink absorbability and transparency of the resulting coating film. These water-dispersed adhesives may be used alone or in combination of two or more.

Water-soluble adhesives include polyvinyl alcohols including proteins such as casein, soy protein, synthetic proteins, various starches such as starch and oxidized starch, and modified polyvinyl alcohols such as polyvinyl alcohol, cationic polyvinyl alcohol and silyl-modified polyvinyl alcohol. , Cellulose derivatives such as carboxymethyl cellulose and methyl cellulose, aqueous polyurethane resins, aqueous polyester resins, and the like.

Among these adhesives, it is preferable to use polyvinyl alcohol from the viewpoint of surface strength.
Polyvinyl alcohol used in the ink fixing layer has different properties depending on the saponification degree, and it is preferable to select the saponification degree according to the purpose.
When polyvinyl alcohol having a saponification degree of 95% or more, more preferably 98% or more is used, the strength of the coating layer is increased, and no foaming occurs during preparation of the coating solution, resulting in extremely high workability during production. It is good.
In addition, when partially saponified polyvinyl alcohol having a saponification degree of 75 to 90% is used, the coating layer has excellent flexibility and is very effective in preventing the breakage.
These polyvinyl alcohols having different saponification degrees may be used alone or in combination depending on the purpose.

Moreover, it is preferable that the polymerization degree of the said polyvinyl alcohol is 3500 or more, and it is especially preferable that it is 3500-5000. If the degree of polymerization is less than 3500, the strength of the ink receiving layer is weak, cracks are likely to occur, and paper dust may be generated during cutting. On the other hand, when it exceeds 5000, it is difficult to obtain sufficient ink absorbability, and the solution viscosity is high, which may make it difficult to handle the coating liquid.

  The amount of the adhesive in the ink fixing layer is preferably 7 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the pigment. If the blending amount is less than 7 parts by mass, the coating film strength may not be sufficient, and if it exceeds 50 parts by mass, the ink absorbability may be impaired.

(Ink fixing agent)
The ink fixing agent has a function of fixing a dye pigment in the ink for ink jet recording, thereby imparting water resistance to the printed image.
As the ink fixing agent, a cationic compound is used, and examples thereof include a cationic resin and a low molecular weight cationic compound (for example, a cationic surfactant).
Cationic resins are preferred in terms of improving printing density, and various known cationic resins that are generally used in ink jet recording materials can be used.

Examples of these cationic resins include (a) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, and (b) an acrylic heavy group having a secondary or tertiary amino group or a quaternary ammonium group. Or acrylamide copolymers thereof, (c) polyvinylamine and polyvinylamidines, (d) dicyan-based cationic compounds represented by dicyandiamide-formalin copolymer, (e) dicyandiamide-polyethyleneamine copolymer (E) epichlorohydrin-dimethylamine copolymer, (to) diallyldimethylammonium-SO ₂ polycondensate, (thi) diallylamine salt-SO ₂ polycondensate, (li) diallyl Dimethylammonium black (U) allylamine salt copolymer, (l) dialkylaminoethyl (meth) acrylate quaternary salt copolymer, (e) acrylamide-diallylamine copolymer, (wa) 5-membered ring amidine structure. And a cationic resin.
In the embodiment of the present invention, these fixing agents are used alone or in combination of two or more.

(Silica-cationic compound aggregate fine particles)
The cationic compound aggregates with the gas phase method silica in a mixed solution with the gas phase method silica to form a silica-cationic compound aggregate.
For this reason, this cationic compound is preferably used in the form of agglomerates with gas phase method silica in advance rather than being used alone.
By the way, the silica-cationic compound aggregate is pulverized and dispersed and used as a silica-cationic compound aggregate fine particle having an average particle size of 0.01 to 1 μm in the coating solution for the ink receiving layer.
The single-phase vapor phase silica used for forming the silica-cationic compound aggregated fine particles is a primary particle having an average particle diameter of 3 to 40 nm. The aggregated fine particles are substantially composed of primary particles. It consists of secondary particles formed by agglomeration.

An outline of a method for producing silica-cationic compound aggregate fine particles will be described.
The addition amount of the cationic compound is adjusted in the range of 1 to 30 parts by mass, preferably 5 to 20 parts by mass with respect to 100 parts by mass of the vapor phase method silica.
When a cationic compound is added to and mixed with the vapor phase silica dispersion, a thickened aggregate dispersion is obtained.
As a method of pulverizing / dispersing the silica-cationic compound aggregate particles into fine particles, a breaking down method (a method of subdividing the bulk material) that gives a strong force by mechanical means is employed.
Examples of the mechanical means include an ultrasonic wave, a high-speed rotating mill, a roller mill, a container driving medium mill, a medium stirring mill, a jet mill, a crusher, a sand grinder, a nanomizer (trade name), and a homomixer.

The silica-cationic compound aggregated fine particles as a pigment and an ink fixing agent are used singly or in combination of two or more. By using this, the transparency, surface strength, smoothness of the ink fixing layer is used. As well as ink absorbency, color developability, weather resistance, water resistance, and the like.

  Further, various auxiliary agents such as a dispersant, a thickener, an antifoaming agent, an antistatic agent, and an antiseptic used in the production of general coated paper are appropriately added to the ink fixing layer. Further, a fluorescent dye and a colorant can be added to the ink fixing layer.

In the ink fixing layer, a single cationic compound may be blended in order to further improve the ink fixing property and improve the water resistance.
Examples of the cationic compound include those used in the silica-cationic compound aggregate, and among these, water-soluble resins or emulsions are preferably used.
In addition, a cationic compound, particularly a cationic resin, blended as a simple substance is often used when a role as an adhesive is also given.

(Method for forming ink fixing layer)
In order to form the ink fixing layer, for example, the coating liquid layer is reduced simultaneously with the application of the ink fixing layer coating liquid or during the drying of the coating liquid layer to which the ink fixing layer coating liquid is applied. Before showing the rate of drying rate, it is effective to produce a film by thickening or crosslinking the coating liquid.
Specifically, the methods listed in the following (A) to (C) can be exemplified and can be appropriately adopted, but are not limited to these methods.

For example,
(A) It contains a hydrophilic resin that forms a hydrogel by electron beam irradiation, and immediately after coating or in the middle of drying of the coated coating layer, the coating layer is reduced at a reduced rate. Before showing, the method of thickening the coating liquid layer by irradiation with an electron beam (forms a hydrogel),
(B) The ink fixing layer is a coating liquid containing an adhesive, and immediately after coating or in the middle of drying of the coated coating liquid layer, the coating liquid layer exhibits a reduced rate of drying. Before, a method of thickening and crosslinking the paint with a compound having crosslinkability with the adhesive,
(C) For example, a temperature-sensitive polymer compound as an adhesive (shown in the temperature region below a certain temperature (temperature-sensitive point) described in JP-A-2003-40916) exhibits hydrophilicity, and in a temperature region higher than the temperature-sensitive point. A method of increasing the viscosity of the coating liquid layer by reducing the temperature of the coating liquid layer immediately after coating,
Etc. can be illustrated.
When the coating layer is formed by the above methods (A) and (B), as the adhesive, the above-mentioned known adhesives used for inkjet recording materials can be used.

  Various known crosslinking agents and gelling agents can be used as the compound having crosslinkability with the adhesive. Examples of the compound having a crosslinking property to polyvinyl alcohol include aldehyde-based crosslinking agents such as glyoxal, epoxy-based crosslinking agents such as ethylene glycol diglycidyl ether, vinyl-based crosslinking agents such as bisvinylsulfonylmethyl ether, boric acid and borax. Examples include boron-containing compounds, glycidyl compounds, zirconium compounds, aluminum compounds, chromium compounds and the like. Among these, a boron-containing compound is particularly preferable because thickening or gelation occurs quickly.

The boron-containing compound is an oxygen acid having a boron atom as a central atom and a salt thereof. Specific examples include orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid, and sodium salts, potassium salts, and ammonium salts thereof. Among these, orthoboric acid and disodium tetraborate are preferably used because they have an effect of appropriately thickening the paint.
Although content of a boron compound is based also on the polymerization degree of a boron compound and polyvinyl alcohol, it is preferable to contain 0.01-2.0 g / m < ² > on the single side | surface of a base material. When the content is 2.0 g / m ² or less, the crosslinking density with the hydrophilic binder does not become too high, and the coating strength can be improved. On the other hand, when the content is 0.01 g / m ² or more, the crosslinking with the hydrophilic adhesive is strengthened, the gelation of the coating is promoted, and the coating film is hardly cracked.

  For example, the ink fixing layer is preliminarily applied and impregnated with a crosslinking agent in the ink fixing layer, and then the ink fixing layer coating liquid is applied, or the ink fixing layer coating liquid is mixed and applied. Alternatively, it is produced by a method such as applying a cross-linking agent after applying the ink fixing layer coating liquid. Among them, it is preferable to apply a crosslinking agent in advance because thickening or gelation can be caused uniformly.

The dry solid coating amount of the ink-fixing layer, but is not limited, it is preferable that generally is 2~100g / ^{m 2,} and more preferably 5 to 50 g / ^{m 2.} When the coating amount is 2 g / m ² or more, the ink absorbency in a high-definition and high-speed printer is sufficient, and when the coating amount is 100 g / m ² or less, the coating film is less likely to crack. Become.

Two or more ink fixing layers can be formed. When the ink fixing layer is formed of two or more layers as described above, the silica and the adhesive constituting each layer may be the same or different.
In addition, two or more types of silica and adhesive may be mixed in the same layer, or a combination thereof may be used.
As the coating apparatus for forming the ink fixing 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, a curtain coater and a die coater are used. I can do it.

Also, a plurality of ink fixing layers can be applied simultaneously using a slide bead coater or the like. When two or more ink fixing layers are applied, it is preferable to use a method in which the upper layer is applied onto the lower layer while the lower layer is not dried, that is, a wet-on-wet method.
Further, the coated ink fixing layer may be subjected to a smoothing process such as super calendering or brushing as necessary.

(Glossy expression layer)
In the recording medium of the present embodiment, a glossy expression layer that expresses gloss is formed on the ink fixing layer.
This gloss developing layer has a gloss developing property that becomes a glossy surface after being casted as described later. Even if a smoothing process such as super calendering or brushing is performed, a certain level of gloss is exhibited, but an excellent gloss is exhibited by casting.
The glossy layer is composed of colloidal particles and paraffin wax as main components and forms the outermost part of the recording material that exhibits gloss.

(Colloidal particles)
The colloidal particles in the gloss developing layer are inorganic particles or organic particles suspended and dispersed in water to form a colloidal shape. By containing the colloidal particles, uniform and high gloss can be obtained. . Examples of the colloidal particles include alumina sols such as colloidal silica, boehmite, and pseudoboehmite, colloidal alumina, cationic aluminum oxides or hydrates thereof, or colloids disclosed in Japanese Patent Publication No. 47-26959. Inorganic particles such as particles coated with alumina on the surface of silica particles, polystyrene, methyl methacrylate, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylate ester and methacrylate ester copolymer, microcapsule, urea resin, Examples thereof include organic particles such as melamine, and two or more of these may be used in combination.

  The colloidal particles of the glossy layer are preferably cationic colloidal particles having a function of fixing ink. Cationic colloidal particles refer to particles in which the surface of the colloidal particles is positively charged. For example, alumina sol such as boehmite and pseudoboehmite, colloidal alumina, cationic aluminum oxide, or a hydrate thereof. Examples thereof include particles obtained by coating the surface of colloidal silica particles with alumina.

(Paraffin wax)
Inclusion of paraffin wax in the glossy layer improves productivity due to improved releasability during mirror finishing, and greatly improves scratches when feeding printers, especially when it is easily damaged. Although the recording density is high and the glossiness is very high as in the present application, the scratch resistance performance is very high even for a recording medium in which paper feed damage is conspicuous. The reason for this is not clear, but the inclusion of paraffinic wax improves the slipperiness of the surface, and the high latent heat of fusion of the paraffinic wax itself, which is also used as a heat storage agent. I think that the wear of the printer and the ink jet recording body at the time is greatly reduced.

Paraffin waxes include paraffin wax and polyethylene wax depending on the molecular weight and branching. Paraffin wax has a relatively small molecular weight, is composed of hydrocarbons having a carbon number distribution of 20 to 40 and a molecular weight of 300 to 550, and is solid at room temperature. The melting point is about 50 to 95 ° C., and the melt viscosity at 140 ° C. is about 4 to 7 mPa · s.
On the other hand, polyethylene wax has a wide molecular weight, ranging from several thousand to several hundred thousand. The melting point is 85 to 130 ° C. or higher, and the melt viscosity at 140 ° C. is wide as 10 to 10,000 mPa · s or higher. Paraffin wax is often separated and extracted from crude oil distilled under reduced pressure, but polyethylene wax is a method of polymerizing ethylene using a catalyst or oxidizes polyethylene to cleave molecular chains to reduce molecular weight. Manufactured.
The paraffin wax in the present invention is preferably a paraffin wax rather than a polyethylene wax. The reason is not clear, but it is presumed that paraffin wax has a lower melting point than polyethylene wax and a lower melt viscosity. That is, as the paraffinic wax used in the present application, a preferable melting point range is 50 to 90 ° C., and a preferable melt viscosity at 140 ° C. is 4 to 7 mPa · s.
The paraffin wax is emulsified and refined with an emulsifier and contained in the glossy layer as an emulsion. Examples of the emulsification method include a phase inversion emulsification method, a natural emulsification method, and a mechanical force emulsification method.

The phase inversion emulsification method refers to the state of water-in-oil emulsification (W / O) emulsification and solubilization, and further solubilization by adding warm water mixed with melted paraffin wax and emulsifier little by little. When this warming water is added, it is inverted and an oil-in-water type (O / W), that is, a water-based emulsification interface is generated to precipitate fine paraffin wax particles.
The natural emulsification method has an interfacial tension at the interface between the melted paraffin wax and the heated water, so the force to reduce the interfacial area works. Paraffin wax becomes fine particles even by force, and if this interfacial tension is made even smaller, the diffusion force works due to the molecular motion of the water of the dispersion medium, and if this exceeds the interfacial tension, it will emulsify naturally.
The mechanical force emulsification method uses the fact that even if the interfacial tension of warm water mixed with melted paraffin wax and emulsifier is large, the wax can be made finer in water if mechanical force exceeding this interfacial tension is applied. It is the method. For this mechanical force, a homomixer, a homogenizer or the like having a high dispersion efficiency is usually used.
As the above-mentioned emulsifier, known cationic emulsifiers, nonionic emulsifiers, and anionic emulsifiers are appropriately used according to the ionicity of the glossy layer.

The average particle size of the paraffin wax emulsion is preferably 0.02 to 0.5 μm, more preferably 0.05 to 0.1 μm. If the average particle size is large, the transparency of the glossy layer is impaired and a clear image cannot be obtained. Conversely, in order to reduce the average particle size, more emulsifier is required, and not only the excellent scratch resistance inherent in paraffin wax is impaired, but ink absorption is inhibited by the emulsifier, and a clear image cannot be obtained. .
The average particle diameter of the paraffin wax emulsion is a value measured using a dynamic light scattering particle size distribution measuring device LB-500 manufactured by Horiba, Ltd.

  The paraffinic wax in the glossy layer is 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass with respect to 100 parts by mass of colloidal particles. If the amount of paraffin wax is less than 0.1 parts by mass, there is a concern about deterioration of productivity due to a decrease in releasability and deterioration of scratches at the time of feeding a printer. There is a risk of problems such as

  In addition to the paraffinic wax in the glossy layer, known waxes can be used as long as the effects of the present invention are not impaired. These waxes include animal-derived waxes (such as beeswax, wool wax, whale wax, shellac wax, and ibota wax), plant-derived waxes (carnauba wax, candelilla wax, wood wax, rice wax, etc.), and petroleum-derived waxes. Wax (microcrystalline wax, etc.), hydrocarbon synthetic wax (Fischer-Tropsch wax), non-hydrocarbon synthetic wax (fatty acid ester wax, fatty acid amide, ketone / amine, hydrogenated oil, etc.), and these Examples include modified and processed waxes (oxidized wax, synthetic resin blend wax, etc.), which are used alone or in combination.

(adhesive)
The glossy layer may contain an adhesive for the purpose of fixing colloidal particles and paraffin wax on the ink fixing layer. By adding an adhesive, the glossy layer becomes stronger, and it is possible to prevent the coating layer from being chipped off from the edge of the paper and preventing the paper feed roll inside the printer from being soiled by the coating layer powder. Ink absorption is hindered, which is not preferable. The required amount of adhesive is determined by the strength of the adhesive, the thickness of the glossy layer, the desired strength, and the required ink absorbency. The adhesive is selected from the above-mentioned adhesives used for the ink fixing layer, and may be used alone or in combination of two or more. Particularly preferred water-dispersible adhesives in the present invention include acrylic resins and urethane resins. Compared to vinyl resins such as styrene-butadiene copolymer resins, methyl methacrylate-butadiene copolymer conjugated diene resins, and ethylene-vinyl acetate copolymer resins, these resins have a smaller particle size. As a result, the recording density is not lowered, which is preferable.
Moreover, polyvinyl alcohols are illustrated as a particularly preferable water-soluble adhesive. Polyvinyl alcohol can greatly change its degree of saponification and polymerization, it is possible to select a resin with characteristics suitable for the paint system, and various characteristics can be added by modification. It is.
When polyvinyl alcohol having a saponification degree of 95% or more, more preferably 98% or more is used, the strength of the coating layer is increased, and no foaming occurs during preparation of the coating solution, resulting in extremely high workability during production. It is good.
In addition, when partially saponified polyvinyl alcohol having a saponification degree of 75 to 90% is used, the coating layer has excellent flexibility and is very effective in preventing the breakage.
These polyvinyl alcohols having different saponification degrees may be used alone or in combination depending on the purpose.
Moreover, it is preferable that the polymerization degree of the said polyvinyl alcohol is 1000 or more, and it is especially preferable that it is 1700-4000. If the degree of polymerization is less than 1000, the gloss layer is weak, cracks are likely to occur, and paper dust may be generated during cutting. On the other hand, if it exceeds 4000, the solution viscosity is high, and the handling surface in adjusting the coating solution may be difficult.
When the colloidal particles in the gloss developing layer are cationic or when an ink fixing agent is blended in the gloss developing layer, it is preferable to use a cationically modified adhesive.
The compounding quantity of an adhesive agent is adjusted in the range of 1-200 mass parts with respect to 100 mass parts of colloidal particles, More preferably, in the range of 10-100 mass parts.
If the blending amount of the adhesive is less than 1 part by mass, the adhesion of the glossy layer is weakened and the coating layer may be lost. Ink jet recording suitability may not be obtained, which is not preferable.

(Other additives)
In addition, the glossy layer may include an ink fixing agent, a dispersant, a crosslinking agent, a thickener (flow modifier), an antifoaming agent, a water-resistant agent (printability improver), an antistatic agent, as necessary. Various additives such as preservatives, ultraviolet absorbers, preservability improvers, fluorescent brighteners, and colorants can be appropriately added.

As the ink fixing agent, the same cationic resin as that used in the ink fixing layer is used.

  Examples of the thickener and flow modifier include (a) synthetic resin copolymers such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer, (b) casein, (c) soybean protein, and synthetic protein. Proteins, (d) various starches such as starch and oxidized starch, (e) PVA, (f) cellulose derivatives such as carboxymethylcellulose and methylcellulose, (g) polycarboxylic acid, polyacrylic acid, acrylic resin emulsion, Polyamide, polyester synthetic resin polymer, (h) nonionic surfactant, and the like are appropriately used.

Examples of the water-resistant agent and printability improver include sodium chloride, ammonium chloride, zinc chloride, magnesium chloride, sodium sulfate, potassium sulfate, ammonium sulfate, zinc sulfate, magnesium sulfate, ferrous sulfate, sodium nitrate, ammonium nitrate, first Sodium phosphate, ammonium phosphate, calcium phosphate, sodium polyphosphate, sodium hexametaphosphate, sodium formate, ammonium formate, sodium acetate, potassium acetate, sodium monochloroacetate, sodium malonate, sodium tartrate, potassium tartrate, potassium citrate, Ammonium and metal salts of inorganic and organic acids such as sodium lactate, sodium gluconate, sodium adipate, sodium dioctylsulfosuccinate, sodium aluminate, Methylamine, diethanolamine, diethylenetriamine, diisopropylamine, triethanolamine, methanolamine, ethanolamine and other amines, phosphate esters, polyoxyethylene alkylphenol ether phosphate ester salts, polyoxyethylene ether phosphate ester salts, alkylphenol ether phosphorus Phosphate esters such as acid ester salts, polyoxymethylene, alkyl ether, polyoxyethylene and aqueous ammonia, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether and adipic acid di Polyfunctional epoxy compounds such as glycidyl ester, urea-formaldehyde compounds, poly De ─ epichlorohydrin compounds, glyoxal, and the like are used as appropriate.

The above-mentioned various additives are added to the glossy layer coating liquid in a range of 0.05 to 10% by mass, preferably 0.1 to 5% by mass as the solid content concentration.
Furthermore, known white pigments such as alumina, colloidal silica, fine silica, clay and calcium carbonate can also be added to the glossy layer coating liquid as other additives.
In addition, when performing the rewetting process mentioned later, the dispersing agent, antifoaming agent, coloring agent, fluorescent dye, antistatic agent, preservative, etc. in the above additives may be added to the wetting liquid used for the rewetting process. good.

(Dry coating amount)
In the present invention, since the pigment in the ink fixing layer is a fine pigment having an average particle size of 0.01 to 1 μm, the transparency and smoothness of the coating film are increased. High glossiness can be obtained with a small coating amount of 0.2 to 4.5 g / m ² , preferably 0.5 to 3 g / m ² . When the dry coating amount is less than 0.2 g / m ² , the glossiness and the print density are inferior, and when the dry coating amount is more than 4.5 g / m ² , the image sharpness decreases due to the deterioration in ink absorbency, Problems such as deterioration in productivity due to an increase in drying load occur.

(Glossing treatment)
The gloss developing layer is preferably subjected to various glossing treatments after coating and drying a coating solution containing the above components.
The glossing treatment can be performed by a super calendar as long as it is glossy to some extent, but it is preferable to perform a casting process in order to obtain a high gloss.

In general, cast processing means that the coating layer is pressed onto a cast drum having a mirror surface (drum made of mirror-finished metal, plastic, glass, etc.), mirror-finished metal plate, plastic sheet, film, glass plate, etc., and dried. The mirror surface is copied onto the coating layer to obtain a smooth and glossy coating layer surface.
In this method, the gloss is developed by casting using a heated mirror drum. (A) The outermost coating layer coating solution is applied onto the substrate so that the coating solution is in a wet state. A method of pressing and drying on a mirror drum heated for a while and then finishing (wet casting method)
(B) A method in which the outermost coating layer coated on the substrate is once dried, then the outermost coating layer is rewet, and then heated to a heated mirror drum and dried to finish (rewet casting method). ,
(C) The outermost coating layer on the substrate is gelled to form a gel-like coating layer, which is pressed onto a heated mirror drum and dried to finish (gelation cast method).
(2) Apply the coating solution for the outermost coating layer directly on the heated mirror drum, and after drying to form the outermost coating layer on the mirror drum, the mirror drum is placed on the substrate. Pressing and finishing the above outermost coating layer by transferring (precast method),
Is mentioned.
In these casting processes, the temperature of the heated mirror drum is, for example, 50 to 150 ° C, preferably 70 to 120 ° C.

Furthermore, a film transfer method can also be adopted as the casting process.
What is film transfer system?
(A) The above-mentioned coating solution for the outermost coating layer is applied onto a substrate, and a smooth film or sheet is stacked while the coating solution is in a wet state, dried, and then smooth. And the method of peeling and finishing the sheet,
(B) Applying the coating solution for the outermost coating layer on a smooth film or sheet, with the substrate surface to be bonded in a wet state to some extent, press against the substrate surface, A method of peeling and finishing a smooth film or sheet after drying,
It is.
Compared to the film transfer method, the cast method using a heated mirror drum tends to be superior in surface smoothness and is more advantageous in terms of productivity and cost.

Any of the above methods may be used for casting, but in the recording medium of the present embodiment, the above-described ink-receiving layer coating solution is applied on a paper substrate and dried. It is preferable to use a wet casting method in which after the coating liquid for the glossy layer is applied, it is immediately pressed onto a heated mirror surface metal drum and dried.
In this wet casting method, a uniform coating layer is easily formed, and a glossy expression layer having a high printing density and excellent gloss is easily obtained.

In each of the above-described casting processes, when applying the coating liquid for the glossy layer, various known coating methods are used, for example, for coating apparatuses such as blades, brush coaters, Champlex coaters, bar coaters, and gravure coaters. The coating method of coating using either can be used.

(Glossiness)
The glossiness of the glossy layer is preferably 25% or more (JIS-P8741). If the gloss level of the glossy layer is lower than 25%, it may be difficult to bring the quality of a recorded image obtained by outputting a photographed image close to that of a silver salt photograph.

<Back layer>
In the present invention, a back surface layer is provided on the back surface, which is the other surface side of the base material not provided with the outermost layer, in order to improve the texture of the photograph, the curling prevention of the ink jet recording material, and the transportability. May be. Although it does not specifically limit in a back surface layer, A pigment and binder type | system | group (For example, colloidal silica and an acrylic emulsion type binder etc.), Organic emulsion type (For example, a silicon type emulsion type binder, an acrylic emulsion type binder etc.) And a hydrophilic / hydrophobic adhesive system (for example, a coating film of starch or polyvinyl alcohol), a laminate (for example, polyethylene) or the like.

  Furthermore, an ink jet recording medium or other recording medium is bonded to the back surface to form a double-sided recording medium, an adhesive layer is formed on the back surface to form a label, or a magnetic card or IC card is bonded to the surface of the card. Well-known means can be applied.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Further, “parts” and “%” in the following examples and comparative examples represent “parts by mass” and “% by mass” of solids excluding water, respectively, unless otherwise specified.

Example 1
[Ink fixing layer coating liquid A]
To 100 parts of cationic silica fine particles, 15 parts of PVA (trade name: PVA-145, polymerization degree 4500, saponification degree 99%, manufactured by Kuraray Co., Ltd.) as an adhesive is mixed, and for an ink receiving layer having a solid content concentration of 12%. A coating liquid A was prepared.
[Glossy layer coating liquid a]
Colloidal silica as colloidal particles (trade name: Snowtex 50, average particle size: 20-30 nm, primary particles, manufactured by Nissan Chemical Industries) 100 parts, acrylic resin as adhesive (trade name: BL740, manufactured by Lion) A composition solution containing 20 parts was mixed, 20 parts of paraffin wax emulsion (trade name: Digit S-5, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.08 μm) was added and further mixed, and then diluted water. Was added to prepare a coating liquid for glossy layer having a solid content concentration of 10%.

[Preparation of inkjet recording material]
After coating the ink fixing layer coating liquid A on one side of the produced paper substrate so that the coating amount is 20 g / m ² , the electron beam irradiation apparatus (ESI Co., Ltd.) is immediately used in a nitrogen gas environment. An electron beam with an acceleration voltage of 175 kV and an irradiation dose of 50 kGy was irradiated by an electro curtain). The coated surface after irradiation was a jelly-like solid, and was hydrogelled. Subsequently, the hydrogelated coating liquid layer was dried to form an ink fixing layer.
Further, after the gloss developing layer coating liquid a was applied onto the ink fixing layer, it was immediately pressed against a mirror drum having a surface temperature of 90 ° C., dried, and peeled to produce an ink jet recording material. At this time, the dry coating amount of the glossy layer was 2 g / m ² .

(Example 2)
A 3% borax aqueous solution is applied on the same paper substrate as in Example 1 so that the dry coating amount is 1.0 g / m ^2, and before drying, the same ink fixing layer coating solution A as in Example 1 is applied. Was coated with a die coater so that the dry coating amount was 20 g / m ² . On this coated surface, PVA was crosslinked with borax to form a jelly-like semi-solid. The semi-solidified coating liquid layer was dried to form an ink fixing layer.
Further, after the gloss developing layer coating liquid a was applied onto the ink fixing layer, it was immediately pressed against a mirror drum having a surface temperature of 90 ° C., dried, and peeled to produce an ink jet recording material. At this time, the dry coating amount of the glossy layer was 2 g / m ² .

(Example 3)
An ink jet recording material was produced in the same manner as in Example 2, except that 20 parts of the paraffin wax emulsion of the gloss developing layer coating solution a was changed to 10 parts.
Example 4
Example 2 is the same as Example 2 except that 20 parts of an acrylic resin, which is an adhesive of the glossy layer coating liquid a, is changed to 20 parts of a urethane resin (trade name: F8570D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Similarly, an ink jet recording material was produced.

(Example 5)
Inkjet recording was carried out in the same manner as in Example 12 except that 20 parts of the acrylic resin, which is the adhesive of the glossy layer coating liquid a in Example 2, was changed to 20 parts of polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray Co., Ltd.). The body was made.

(Example 6)
In Example 2, the paraffin wax emulsion (trade name: Digit S-5, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.08 μm) of the gloss developing layer coating solution a was paraffin wax emulsion (trade name: Digit EY, interactive). An ink jet recording material was produced in the same manner as in Example 2 except that the average particle size was changed to 0.18 μm (manufactured by Chemical Co., Ltd.). At this time, the dry coating amount of the glossy layer was 2 g / m ² .

(Example 7)
An ink jet recording material was produced in the same manner as in Example 5 except that the dry coating amount of the glossy layer in Example 5 was 1 g / m ² .

(Example 8)
The following ink fixing layer coating solution B was applied to one surface side of the same paper substrate as in Example 1 so that the dry coating amount was 10 g / m ² . Further, a wet-on-wet method (the ink fixing layer coating liquid A while the ink fixing layer B is not dried) is applied so that the dry coating amount of the ink fixing layer coating liquid A is 10 g / m ^2. Coating). On this coated surface, PVA was crosslinked with borax to form a jelly-like semi-solid. The semi-solidified coating liquid layer was dried to form ink fixing layers B and A.
Next, after applying the gloss developing layer coating liquid b below on the ink fixing layer A, while in a wet state, it is pressed against a mirror drum having a surface temperature of 90 ° C., dried and peeled off. An ink jet recording material was produced. The dry coating amount of the glossy layer was 2 g / m ² .
[Ink fixing layer coating solution B]
Kaolin (trade name: ULTLA WHITE 90, average particle size 0.7 μm, manufactured by Engelhard) and titanium oxide (trade name: R-21, average particle size 0.5 μm, rutile type, manufactured by Sakai Chemical Co., Ltd.) To 50 parts, 30 parts of acrylic resin latex (trade name: JK-7000, manufactured by Meisei Chemical Co., Ltd.) as an adhesive and 13 parts of borax as a coagulant are added, and an ink fixing layer coating liquid B having a solid content concentration of 20% is added. Prepared.
[Glossy layer coating liquid b]
Cationic colloidal silica as colloidal particles (trade name: SJ4001, average particle size: 40 nm, primary particles, manufactured by Grace) 100 parts, urethane resin as adhesive (trade name: F8570D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A composition solution containing 20 parts was mixed, and 20 parts of paraffin wax emulsion (trade name: Digit EY, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.18 μm) was added and further mixed, and the solid content concentration was 10%. The coating liquid for glossy layer was prepared.

Example 9
In Example 8, the paraffin wax emulsion (trade name: Digit S-5, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.08 μm) of the gloss developing layer coating liquid b was converted into a paraffin wax emulsion (product name: Digit S-5, An ink jet recording material was obtained in the same manner as in Example 8 except that the average particle size was changed to 0.08 μm (manufactured by Kyodo Chemical Co., Ltd.). The dry coating amount of the glossy layer was 2 g / m ² .

(Example 10)
In Example 4, the colloidal particles of the glossy layer coating liquid were changed to alumina sol (trade name: Cataloid AS-3, particle size 100 nm × 10 nm, manufactured by Catalytic Chemical Co., Ltd.), as in Example 4. Thus, an ink jet recording material was obtained. The dry coating amount of the glossy layer was 2 g / m ² .

Example 11
In Example 2, a paraffin wax emulsion (trade name: Digit S-5, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.08 μm) of the gloss developing layer coating liquid a was converted to a polyethylene wax (trade name). : PEM-17, manufactured by San Nopco, average particle size 0.03 μm), an ink jet recording material was produced in the same manner as in Example 2. At this time, the dry coating amount of the glossy layer was 2 g / m ² .

Example 12
In Example 2, an ink jet recording material was obtained in the same manner as in Example 2 except that the amount of dilution water added to the glossy layer a was adjusted to a solid content concentration of 30%. The dry coating amount of the glossy layer was 8 g / m ² .

(Comparative Example 1)
In Example 2, an ink jet recording material was obtained in the same manner as in Example 2 except that no paraffin wax was blended in the glossy layer coating liquid a. The dry coating amount of the glossy layer was 2 g / m ² .
(Comparative Example 2)
In Example 2, an ink jet recording material was obtained in the same manner as Example 2 except that the colloidal particles were not blended in the glossy layer coating liquid a.

(Comparative Example 3)
An ink jet recording material was obtained in the same manner as in Example 1 except that the ink fixing layer coating solution A was changed to the following ink fixing layer coating solution C in Example 2. The dry coating amount of the glossy layer was 2 g / m ² .
[Ink fixing layer coating solution C]
100 parts of a dispersion of wet silica (trade name: Nipgel AY-603, average particle size 6 μm, manufactured by Tosoh Silica) as a pigment, and 20 parts of polyvinyl alcohol (trade name: R-1130, manufactured by Kuraray) as an adhesive As an ink fixing agent, 10 parts of a cationic resin (trade name: Unisense CP-103, manufactured by Senka) was added to prepare an ink-receiving layer coating liquid C having a solid concentration of 20%.

(Comparative Example 4)
The following ink fixing layer coating liquid D was applied to one surface side of the same paper substrate as in Example 2 so that the dry coating amount was 20 g / m ^2, and then the following coagulating liquid was added to the ink fixing layer. After coating to be 10% by weight with respect to the weight of polyvinyl alcohol in the coating liquid D, while the surface of the resulting coating layer is in a wet state, it is pressed against a mirror drum having a surface temperature of 100 ° C. and dried. Then, it was peeled off to produce an ink jet recording material.
[Ink fixing layer D]
100 parts of a composite of alumina and silica (trade name: VP DOP3375, average particle size 50 nm, manufactured by Nihon Aeruji) as a pigment, 20 parts of polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray Co., Ltd.) as an adhesive, a release agent 3 parts of nonionic paraffin wax (trade name: Digit EK, manufactured by Kyoyo Chemical Co., Ltd., average particle size 0.16 μm) and 10 parts of cationic resin (trade name: Papiogen P-105, manufactured by Senka) as an ink fixing agent An ink receiving layer coating liquid C having a solid content concentration of 14% was prepared.
[Coagulation liquid]
As a coagulant, borax was dissolved in water to prepare a coagulation liquid having a solid content concentration of 5%.

(Comparative Example 5)
An ink jet recording material was obtained in the same manner as in Comparative Example 4 except that the blending amount of the paraffin wax in the ink fixing layer D was 70 parts in Comparative Example 4.
(Comparative Example 6)
In Example 12, a paraffin wax emulsion (trade name: Digit S-5, manufactured by Kyoyo Chemical Co., Ltd., average particle size of 0.08 μm) was converted into a paraffin wax emulsion (product name: Hydrin P7, manufactured by Chukyo Yushi Co., Ltd., average particle size of 0.8 μm). An ink jet recording material was obtained in the same manner as in Example 8 except that the above was changed.

<Evaluation method>
The ink absorbability of the ink jet recording material, the sharpness of the recorded image, the scratch resistance at the time of feeding the printer, the glossiness, and the productivity were evaluated by the following methods, and the results are shown in Table 1.
Note that the clarity of the recorded image was evaluated by measuring the color density of the recorded image.
For the ink jet printer, CANON, trademark: iP-4300, print mode: glossy paper, clean mode was used.

"Ink absorbability (print spots)"
Green ink was solid-printed on the ink jet recording medium, and whether or not there were spots in the solid-printed image was visually observed and evaluated in the following three stages.
Print spots are a phenomenon that occurs when the ink that has been struck first is not completely absorbed by the coating layer of the ink jet recording body, and the next ink comes and overlaps the surface, and the ink absorption speed is slow. Then, it will appear prominently.
5: No print spots are seen.
4: Print spots are slightly seen, but at a level where there is no practical problem.
3: Slightly large print spots, but at a level that is not a problem for practical use.
2: Level with many printed spots and problematic in practical use.
1: There are so many printed spots that it is not practical.

“Clarity of recorded image (print density)”
The ink jet recording medium was solid-printed with black ink, and the color density was measured with a Macbeth reflection densitometer (model: Gretag Macbeth RD-19, manufactured by Macbeth). The print mode was set to glossy paper, clean mode, and no matching only when measuring the color density.

"Scratch resistance when feeding the printer"
Recording is performed by a paper feeding method (C-type paper feeding) in which an ink jet recording body is set in a paper feeding tray below the printer iP4300 with a printing surface facing downward, and the recording body is rotated inside the printer so that the printing surface faces upward. After printing with solid black on the entire surface of the body, the surface of the printed part was visually observed for scratches.
5: No scratches are seen.
4: Scratches are slightly seen, but practically no problem.
3: Slightly scratched, but practically no problem.
2: Level with many scratches and practical problems.
1: A level with many scratches that cannot be put to practical use.

"Glossiness"
The evaluation of the 20-degree specular gloss was performed by measuring the surface of the recording body at an incident / reflection angle of 20 degrees using a digital gloss meter (GM-26D) manufactured by Murakami Color Research Laboratory in accordance with JIS-P8741.

"productivity"
After coating and solidifying the outermost layer of the ink jet recording body, it is pressure-bonded to a mirror drum heated to 90 ° C. to give a gloss treatment. After 6 seconds, the ink jet recording body is peeled off from the mirror drum, and the ink jet recording body is formed on the mirror surface. The following criteria evaluated whether there was any remaining coating layer.
5: There is no residue on the drum surface, the releasability is excellent, and the productivity is extremely high.
4: There is almost no residue on the drum surface, excellent releasability, and high productivity.
3: Residual on the drum surface is somewhat visible but can be produced normally.
2: A lot of residue is observed on the drum surface, a partial omission of the coating layer of the recording medium can be visually recognized, the release property is inferior, and the productivity is low.
1: The coating layer adheres to the drum surface, the coating layer of the recording material is lost, the releasability is very poor, and the productivity is extremely poor.

As is apparent from Table 1, the glossy ink jet recording material of this example has both glossiness and ink absorption, is hardly damaged when fed to the printer, and is excellent in productivity.
On the other hand, it was found that the comparative example was evaluated as a practically problematic level for any of the evaluation items.

Claims (7)

In an ink jet recording body in which an ink fixing layer and a gloss developing layer are sequentially laminated on a support, the ink fixing layer contains a pigment having an average particle diameter of 0.01 to 1 μm, and the gloss developing layer is formed of colloidal particles. And an paraffin wax having an average particle size of 0.02 to 0.5 μm. ^2. The ink jet recording material according to claim 1, wherein the glossy layer has a dry coating amount of 0.2 to 4.5 g / m < ² >. The ink jet recording material according to claim 1 or 2, wherein the glossy layer contains 0.1 to 50 parts by mass of paraffinic wax with respect to 100 parts by mass of colloidal particles. The inkjet recording according to any one of claims 1 to 3, wherein the gloss developing layer is a cast-finished layer, and the surface of the gloss developing layer has a 20 ° gloss mirror gloss (JIS-P8741) of 25% or more. body. The inkjet recording body according to any one of claims 1 to 4, wherein the glossy layer further contains at least one adhesive selected from a water-soluble adhesive and a water-dispersible adhesive. 6. The ink jet recording material according to claim 5, wherein the water dispersible adhesive is an acrylic resin or a urethane resin. 6. The ink jet recording material according to claim 5, wherein the water-soluble adhesive is polyvinyl alcohol.