JP2001096898A - Inkjet recording materials - Google Patents

Abstract

(57) Abstract: Provided is an ink jet recording material in which ink absorption and gloss are raised to a high level by using fumed silica and cracks and breaks are improved. An ink jet recording material comprising a polyolefin resin-coated paper support coated with an ink-receiving layer containing fumed silica, wherein the support has a water content of 6%.
% Or more, and an undercoat layer on the surface of the support on which the ink receiving layer is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording material, and more particularly to an ink jet recording material having no cracks or breaks on the surface of an ink receiving layer, and having high gloss and ink absorbency.

[0002]

2. Description of the Related Art As a recording material used in an ink jet recording system, a pigment such as amorphous silica is coated on a support called a normal paper or an ink jet recording paper by a porous material comprising a water-soluble binder such as polyvinyl alcohol. There is known a recording material provided with an ink absorbing layer.

[0003] For example, Japanese Patent Application Laid-Open No. 55-51583,
Nos. 6-157, 57-107879, 57-10
No. 7880, No. 59-230787, No. 62-160
No. 277, No. 62-184879, No. 62-1833
As disclosed in JP-A-82 and JP-A-64-11877, a recording material obtained by applying a silicon-containing pigment such as silica to a paper support together with an aqueous binder has been proposed.

[0004] Also, Japanese Patent Publication No. 3-56552,
No. 188287, No. 10-81064, No. 10
No.-119423, No. 10-175365, No. 10
-203006, 10-217601, 11
No. -20300, No. 11-20306, No. 11-
No. 34481 and the like disclose a recording material using fine particles of silica synthesized by a gas phase method (hereinafter referred to as gas phase silica). The fumed silica is an ultrafine particle having an average primary particle diameter of several nm to several tens of nm, and is characterized by high gloss and high ink absorption. But,
Since they are ultrafine particles, there is a problem that cracks and breaks are easily generated on the surface of the ink receiving layer.

[0005] Cracks are minute surface cracks that occur when the ink receiving layer is coated and dried, and fold cracks occur when the recording material is bent when the sheet-like recording material is handled. It is a phenomenon that occurs. In applications for printing with commercial inkjet plotters, such as posters and in-store POPs, which have been attracting attention in recent years, since large-sized sheets are handled, folding cracks are likely to occur, which is a serious problem.

[0006] On the other hand, paper has conventionally been generally used as a support for the ink jet recording material, and the paper itself has a role as an ink absorbing layer. In recent years, while a photo-like recording sheet has been demanded, a recording sheet using a paper support has problems such as gloss, texture, water resistance, cockling (wrinkles or wavy) after printing, and is water-resistant. For example, a resin-laminated paper (polyolefin resin-coated paper) obtained by laminating a polyolefin resin such as polyethylene on both sides of paper has been used. However, these water-resistant supports are
Since the ink cannot be absorbed unlike the paper support, the ink absorbing property of the ink receiving layer provided on the support is important. The recording material had to be coated with a large amount of pigment. By increasing the coating amount of the pigment, cracks and breaks were apt to occur and the quality was remarkably reduced.

Further, in order to obtain higher ink absorbency, it is necessary to reduce the content ratio of the binder amount to the fumed silica. However, by reducing this ratio, cracks and breaks are increasingly caused. It is easy to occur.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording material which uses fumed silica to raise ink absorption and gloss to a high level and has improved cracking and breakage. It is in.

[0009]

The object of the present invention is to provide an ink jet recording material comprising a polyolefin resin-coated paper support on which an ink receiving layer containing fumed silica is applied. The rate is 6% or more,
In addition, the present invention has been attained by an ink jet recording material having an undercoat layer on the ink receiving layer coated surface of the support.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyolefin resin-coated paper support (hereinafter, referred to as resin-coated paper) used in the present invention will be described in detail.
The resin-coated paper used in the present invention has a water content of 6% or more. It is preferably in the range of 6.5 to 9.0%,
More preferably, it is in the range of 7.0 to 9.0%. The water content of the resin-coated paper can be measured using any moisture measurement method. For example, an infrared moisture meter, an absolute dry weight method, a dielectric constant method, a Karl Fischer method and the like can be used.

The base paper constituting the resin-coated paper is not particularly limited, and generally used paper can be used, and more preferably, smooth base paper used for a photographic support, for example, is preferable. As the pulp constituting the base paper, natural pulp, recycled pulp, synthetic pulp, etc. may be used alone or in combination.
Used as a mixture of more than one species. The base paper is blended with additives generally used in papermaking, such as a sizing agent, a paper strength enhancer, a filler, an antistatic agent, a fluorescent whitening agent, and a dye.

Further, a surface sizing agent, a surface paper strengthening agent, a fluorescent whitening agent, an antistatic agent, a dye, an anchoring agent and the like may be coated on the surface.

The thickness of the base paper is not particularly limited, but preferably has good surface smoothness, for example, by applying pressure by using a calender or the like during or after paper making, and has a basis weight of 30%. ~250g / m ² is preferred.

Examples of the polyolefin resin for coating the base paper include homopolymers of olefins such as low-density polyethylene, high-density polyethylene, polypropylene, polybutene and polypentene, and copolymers composed of two or more olefins such as ethylene-propylene copolymer. And mixtures thereof, and those having various densities and melt viscosity indices (melt index) can be used alone or as a mixture thereof.

In the resin of the resin-coated paper, white pigments such as titanium oxide, zinc oxide, talc and calcium carbonate, fatty acid amides such as stearamide, arachidic amide, zinc stearate, calcium stearate, stearic acid Aluminum, metal salts of fatty acids such as magnesium stearate, antioxidants such as Irganox 1010 and Irganox 1076, blue pigments and dyes such as cobalt blue, ultramarine blue, cecilian blue, and phthalocyanine blue, cobalt violet, fast violet, and manganese purple It is preferable to add various additives such as magenta pigments and dyes, fluorescent brighteners and ultraviolet absorbers in an appropriate combination.

The resin-coated paper is produced by a so-called extrusion coating method in which a polyolefin resin is cast on a running base paper in a state of being heated and melted, and both surfaces thereof are coated with the resin. Further, before coating the resin on the base paper, the base paper is preferably subjected to an activation treatment such as a corona discharge treatment or a flame treatment. It is not necessary to coat the back surface with a resin, but it is preferable to coat the resin from the viewpoint of curling prevention. The back surface is usually a matte surface, and the front surface or both front and back surfaces can be subjected to an activation treatment such as a corona discharge treatment or a flame treatment as required. The thickness of the resin coating layer is not particularly limited, but is generally 5 to 50 μm thick on the surface or on both sides.

The method of adjusting the water content of the resin-coated paper is generally a method of adjusting the drying by a drier when making the base paper (paper base) or providing a humidity control zone after the drying is completed. .

The resin-coated paper is produced by heating and melting a polyolefin resin with an extruder, extruding a film between a base paper and a cooling roll, pressing and cooling. On this occasion,
The cooling roll is used for forming the surface shape of the polyolefin resin coating layer, and the surface of the resin layer is formed into a mirror surface, a finely rough surface, or a patterned, for example, silk-like or mat-like shape depending on the shape of the cooling roll surface. be able to.

In the present invention, the center plane average roughness (SRa) of the surface of the resin layer on the side of the resin-coated paper on which the ink receiving layer is provided
However, it is preferable that the surface is finely roughened or molded so as to be 0.11 or more. Preferably, an SRa value of 0.12 to 5.00 is used, which is finely roughened or molded.

The center plane average roughness (SRa) is a cut-off value of 0.1 measured using a stylus type three-dimensional surface roughness meter.
The SRa value at 8 mm, which is defined by the following equation (1).

[0021]

(Equation 1) In Equation 1, Wx represents the length of the sample surface area in the x-axis direction, Wy represents the length of the sample surface area in the y-axis direction, and Sa represents the area of the sample surface area.

Specifically, as a stylus type three-dimensional surface roughness meter and a three-dimensional roughness analyzer, SE-3A manufactured by Kosaka Laboratory, Ltd.
Using a K-type machine and a SPA-11 type machine, the cut-off value is 0.8 mm, Wx = 20 mm, Wy = 8 mm, therefore:
It can be obtained under the condition of Sa = 160 mm ² .

The resin-coated paper used in the present invention has an undercoat layer on the surface on which the ink receiving layer is provided. The undercoat layer is a layer which has been previously coated and dried on the surface of the resin layer of the support before the ink receiving layer is applied. The undercoat layer mainly contains a water-soluble polymer or polymer latex capable of forming a film. Preferred are water-soluble polymers such as gelatin, polyvinyl alcohol, polyvinylpyrrolidone, and water-soluble cellulose, and particularly preferred is gelatin. The adhesion amount of these water-soluble polymers is 10 to
Preferably ^{500mg / m 2, 20~300mg / m} 2 is more preferable. Further, the undercoat layer preferably further contains a surfactant and a hardener. Further, it is preferable to perform corona discharge before applying the undercoat layer to the resin-coated paper.

In the present invention, a resin-coated paper having a moisture content of 6% or more, having an undercoat layer, and having a finely roughened surface or molded so that the surface of the resin layer has an SRa value of 0.11 or more is used. Thereby, a higher effect can be obtained.

The support in the present invention has an antistatic property,
Various back coat layers can be applied for transportability, curl prevention and the like. The back coat layer can contain an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like in an appropriate combination.

The ink jet recording material of the present invention has an ink receiving layer containing fumed silica on the above-mentioned polyolefin resin-coated paper support. The fumed silica contains 50% by weight or more, preferably 60% by weight or more, and more preferably 65% by weight or more based on the total solid content of the ink receiving layer.

The silica fine particles used in the present invention are obtained by a gas phase method. Synthetic silica includes those obtained by a wet method and those obtained by a gas phase method. Usually, silica fine particles often refer to wet process silica. As the wet process silica, silica sol obtained by double decomposition with an acid or the like of sodium silicate or an ion exchange resin layer, or colloidal silica obtained by heating and aging this silica sol,
The silica sol is gelled and the formation conditions are changed to change silica gel, where the primary particles of several microns to 10 microns become siloxane-bonded three-dimensional secondary particles, furthermore silica sol, sodium silicate, sodium aluminate Synthetic silicate compounds mainly composed of silicic acid, such as those obtained by heating and producing the like.

The fumed silica used in the present invention is also called a dry method with respect to a wet method, and is generally produced by a flame hydrolysis method. Specifically, a method of making silicon tetrachloride by burning it with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane may be used alone or in a silicon tetrachloride. And can be used in a mixed state. The fumed silica is commercially available as Aerosil from Nippon Aerosil Co., Ltd. and QS type from Tokuyama Co., Ltd. and can be obtained.

The average particle size of the primary particles of the fumed silica used in the present invention is preferably 30 nm or less. In order to obtain higher gloss, the average particle size is 3 to 10 nm and the specific surface area by the BET method is 250 m ² / g. Or more (preferably 250 to 50
(0 m ² / g). The BET method referred to in the present invention is one of the methods for measuring the surface area of a powder by a gas phase adsorption method, and is a method for determining the total surface area of 1 g of a sample, that is, the specific surface area, from an adsorption isotherm. Usually, nitrogen gas is often used as the adsorbed gas, and the method of measuring the amount of adsorption from the change in pressure or volume of the gas to be adsorbed is most often used. The most prominent for expressing isotherms for multimolecular adsorption is the Brunauer, Emmett, Teller equation, BE
It is called T type and is widely used for determining the surface area. BET
The surface area is obtained by calculating the amount of adsorption based on the formula and multiplying the area occupied by one adsorbed molecule on the surface.

In the present invention, the amount of fumed silica contained in the ink receiving layer is preferably from 10 to 30 g / m ² ,
The range is more preferably from 13 to 30 g / m ² . When the content of the fumed silica is more than the above range, cracks are liable to occur, and when the content is small, the ink absorbency is reduced. The ink receiving layer containing fumed silica preferably has a binder in order to maintain the properties as a film. As the binder, various known binders can be used, but a hydrophilic binder which has high transparency and can obtain higher permeability of the ink is preferably used. In the use of the hydrophilic binder, it is important that the hydrophilic binder does not swell at the initial penetration of the ink and does not close the voids.From this viewpoint, a hydrophilic binder having a relatively low swelling property at around room temperature is preferable. Used. Particularly preferred hydrophilic binders are fully or partially saponified polyvinyl alcohols or cationically modified polyvinyl alcohols. For dispersion of fumed silica,
A commonly known disperser such as a high-pressure homogenizer and a ball mill can be used.

Particularly preferred among polyvinyl alcohols are those partially or completely saponified with a degree of saponification of 80 or more. Polyvinyl alcohol having an average degree of polymerization of 500 to 5000 is preferred.

As the cation-modified polyvinyl alcohol, for example, as described in JP-A No. 61-10483, a primary to tertiary amino group or a quaternary ammonium group is added to the main chain or side chain of polyvinyl alcohol. It is a polyvinyl alcohol contained therein.

Although other hydrophilic binders can be used in combination, the content is preferably 20% by weight or less based on polyvinyl alcohol. The amount of the hydrophilic binder used together with the fumed silica is preferably 30% by weight or less, more preferably 10 to 28% by weight, based on the fumed silica. In order to obtain high ink absorbency, it is preferable to reduce the content ratio of the binder to the fumed silica, but cracks and breaks are more likely to occur. Therefore, the most important feature of the present invention is that cracks and breaks can be prevented without lowering the ink absorbency.

In the present invention, cracking can be further prevented by including a water-soluble metal compound in the ink receiving layer. Accordingly, it is possible to further reduce the amount of the hydrophilic binder and further increase the amount of the fumed silica to improve the ink absorption.

The water-soluble metal compound used in the present invention is
For example, as water-soluble polyvalent metal salts, calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium,
And water-soluble salts of metals selected from tungsten and molybdenum. Specifically, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chlorinated chloride Copper, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate,
Nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel ammonium sulfate hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate , Aluminum chloride hexahydrate, ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate , Zirconium acetate, zirconium chloride, zirconium chloride octahydrate, zirconium hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate, citric acid Sodium tungsten, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride And n-molybdophosphate n hydrate.

In the present invention, a water-soluble aluminum compound or a water-soluble compound containing a Group 4A element in the periodic table is particularly preferable. As the water-soluble aluminum compound, for example, as an inorganic salt, aluminum chloride or a hydrate thereof, aluminum sulfate or a hydrate thereof, ammonium alum and the like are known. Further, there is a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer. Particularly, a basic polyaluminum hydroxide compound is preferable.

The basic polyaluminum hydroxide compound has a main component represented by the following general formula 1, 2 or 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ ,
It is a water-soluble polyaluminum hydroxide stably containing basic and high-molecular polynuclear condensed ions such as [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , and the like. .

[Al ₂ (OH) _n Cl _6-n ] _m Formula 1 [Al (OH) ₃ ] _n AlCl ₃ Formula 2 Al _n (OH) _m Cl _(3n-m) 0 <m < 3n ・ ・ Equation 3

These are water treatment agents under the name of polyaluminum chloride (PAC) from Taki Chemical Co., Ltd., and polyaluminum hydroxide (Paho) from Asada Chemical Co., Ltd. It is marketed by RIKEN GREEN under the name Purachem WT and from other manufacturers for the same purpose, and various grades are readily available. In the present invention, these commercial products can be used as they are,
Some substances have an inappropriately low pH, and in such a case, the pH can be appropriately adjusted and used.

The water-soluble compound containing a Group 4A element in the periodic table used in the present invention is not particularly limited as long as it is water-soluble, but a water-soluble compound containing titanium or zirconium is preferred.
For example, as a water-soluble compound containing titanium, titanium chloride,
Titanium sulfate, as water-soluble compounds containing zirconium, zirconium acetate, zirconium chloride, zirconium oxychloride, zirconium hydroxychloride, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium ammonium carbonate, zirconium potassium carbonate, zirconium sulfate And zirconium fluoride compounds are known. Some of these compounds have an inappropriately low pH. In such a case, the pH can be appropriately adjusted and used. In the present invention, the term "water-soluble" refers to a condition in which 1% by weight or more is dissolved in water at normal temperature and normal pressure.

In the present invention, the content of the water-soluble metal compound in the ink receiving layer is from 0.1 g / m ^{2 to} 10 g / m ² .
m ^2, preferably from ^{0.2g / m 2 ~5g / m 2} .

In the present invention, it is preferable to include a cationic polymer in order to improve water resistance. Examples of the cationic polymer include polyethyleneimine, polydiallylamine, polyallylamine, and JP-A-59-20696.
Nos. 59-33176, 59-33177, 59-15088, 60-11389, and 60
No. 49990, No. 60-83882, No. 60-10
No. 9894, No. 62-198493, No. 63-494
No. 78, No. 63-115780, No. 63-28068
No. 1, JP-A-1-40371, JP-A-6-234268
Polymers having a primary to tertiary amino group and a quaternary ammonium base described in JP-A Nos. 7-125411 and 10-193776 are preferably used. The molecular weight of these cationic polymers is preferably 5,000 or more, more preferably about 5,000 to 100,000.

The amount of these cationic polymers used is 1 to 10% by weight, preferably 2 to 7% by weight, based on fumed silica.

The ink receiving layer in the present invention can contain various oil droplets in order to improve the brittleness of the film. Such oil droplets include hydrophobic high-boiling organic solvents having a solubility in water at room temperature of 0.01% by weight or less (for example, liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, etc.) and polymer particles ( For example, particles obtained by polymerizing one or more polymerizable monomers such as styrene, butyl acrylate, divinylbenzene, butyl methacrylate, and hydroxyethyl methacrylate) can be contained. Such oil droplets can be preferably used in the range of 10 to 50% by weight based on the hydrophilic binder.

In the present invention, the ink receiving layer preferably contains a hardener together with a hydrophilic binder. Specific examples of the hardener include formaldehyde, aldehyde compounds such as glutaraldehyde, diacetyl,
Ketone compounds such as chloropentanedione, bis (2-
(Chloroethyl urea) -2-hydroxy-4,6-dichloro-1,3,5 triazine, U.S. Pat. No. 3,288,7
No. 75, a compound having a reactive halogen, divinyl sulfone, a compound having a reactive olefin as described in U.S. Pat. No. 3,635,718, and an N-type compound as described in U.S. Pat. No. 2,732,316. Methylol compounds, isocyanates described in U.S. Pat. No. 3,103,437, U.S. Pat. Nos. 3,017,280 and 2,
Aziridine compounds as described in 983,611, carbodiimide compounds as described in U.S. Pat. No. 3,100,704, epoxy compounds as described in U.S. Pat. No. 3,091,537, halogen carboxaldehydes as mucochloric acid And dioxane derivatives such as dihydroxydioxane; inorganic hardeners such as chromium alum, zirconium sulfate, boric acid and borate;
They can be used alone or in combination of two or more. Among these, boric acid or borate is particularly preferred. The addition amount of the hardener is preferably from 0.1 to 40% by weight based on the hydrophilic binder constituting the ink receiving layer,
More preferably, it is 0.5 to 30% by weight.

In the present invention, the ink-receiving layer may further contain, in addition to a surfactant and a hardener, a coloring dye, a coloring pigment, a fixing agent for the ink dye, an ultraviolet absorber, an antioxidant, a dispersant for the pigment, Antifoaming agent, leveling agent, preservative, optical brightener,
Various known additives such as a viscosity stabilizer and a pH adjuster can also be added.

In the present invention, the method of applying the undercoat layer and the ink receiving layer is not particularly limited, and a known coating method can be used. For example, slide bead method, curtain method, extrusion method, air knife method,
There are a roll coating method, a ked bar coating method, a bar coater method, a dip method and the like.

[0048]

EXAMPLES The present invention will be described below in detail with reference to examples, but the contents of the present invention are not limited to the examples.

Example 1 <Preparation of Polyolefin Resin-Coated Paper Support> A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and softwood bleached sulphite pulp (NBSP) was beaten to 300 ml with Canadian Standard Freeness to give pulp. A slurry was prepared. As a sizing agent, alkyl ketene dimer to pulp is 0.5% by weight, polyacrylamide is 1.0% by weight to pulp, cationized starch is 2.0% by weight to pulp, and polyamide epichlorohydrin resin is a sizing agent. 0.5% by weight of pulp was added and diluted with water to obtain a 1% slurry. The slurry was paper-made with a fourdrinier paper machine so as to have a basis weight of 170 g / m ^{2, and} was dried and conditioned to obtain a base paper of a polyolefin resin-coated paper. A polyethylene resin composition obtained by uniformly dispersing 10% by weight of anatase type titanium with respect to 100% by weight of a resin having a density of 0.918 g / cm ³ and 100% by weight of a resin was prepared.
It was melted at 20 ° C., extruded at a rate of 200 μm / min to a thickness of 30 μm, and extruded using a finely roughened cooling roll. On the other side, a blended resin composition of 70 parts by weight of a high-density polyethylene resin having a density of 0.962 g / cm ³ and 30 parts by weight of a low-density polyethylene resin having a density of 0.918 was similarly melted at 320 ° C.
Extrusion coating was performed to a thickness of 30 μm.

At the time of base paper making, the water content was adjusted so as to have a water content as shown in Table 1 to prepare a polyolefin resin-coated paper support having various water contents. Each of these supports has an SRa value of 0.15.

After subjecting the polyolefin resin-coated paper to a high-frequency corona discharge treatment, an undercoat layer having the following composition was coated and dried so that the gelatin content was 50 mg / m ² , thereby preparing a support. On the other hand, a support having no undercoat layer was also prepared. In addition, a part represents a weight part.

<Undercoat layer> Lime-treated gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chromium alum 10 parts

An ink receiving layer coating solution having the following composition was applied to the above support by a slide coating apparatus and dried. The ink receiving layer coating solution shown below was prepared such that the fumed silica had a solid content of 9% by weight. This coating solution was applied such that the coating amount of fumed silica was 19 g / m ² as a solid content.
Dried.

<Coating solution for ink receiving layer> 100 parts of fumed silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g by BET method) 4 parts of dimethyldiallylammonium chloride homopolymer (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) , Sharoll DC902P, molecular weight 9000) Basic polyaluminum hydroxide 4 parts (trade name: Hyurachem WT, manufactured by Riken Co., Ltd.) Boric acid 3 parts Polyvinyl alcohol 20 parts (Saponification degree 88%, average polymerization degree 3500) Surface activity 0.3 parts

The recording material produced as described above was evaluated for ink absorbency, glossiness, cracks and breakage. The ink absorbency is plotter (Novajet-PRO42 manufactured by ENCAD).
E) and GS ink, C, M and Y are each 1
Printing was performed at 50%. Immediately after printing, the PPC paper was overlaid on the printing portion and pressed lightly, and the amount of ink transferred to the PPC paper was visually observed and evaluated according to the following criteria. Table 1 shows the results. ：: No transfer at all. Δ: Transfer slightly. ×: Transfer considerably.

<Gloss> A 75-degree specular gloss was measured according to the method described in JIS-P8142.

<Cracks> Cracks on the surface of the ink receiving layer were observed with and without a 10-fold loupe and a loupe, and visually evaluated according to the following criteria. ：: No cracking was observed even when enlarged with a loupe. Δ: Some cracks can be confirmed with a loupe, but not without a loupe. ×: Cracks can be confirmed without a loupe.

<Breakage> Curvature when a crack occurs on the surface when an unprinted ink jet recording material is cut into a size of 2 cm × 8 cm and bent in the long side direction with the print surface up. It was evaluated by measuring the radius. The smaller the radius of curvature, the better. A: No breakage occurs even if the radius of curvature is 5 mm. ：: Breakage occurs when the radius of curvature is 6 to 10 mm. Δ: Breakage occurs when the radius of curvature is 11 to 20 mm. X: Breakage occurs when the radius of curvature is 21 mm or more.

[0059]

[Table 1] ─────────────────────────────────── Support Subbing layer Ink absorption Gloss Cracking Crack Remarks Water content (%) (%) ─────────────────────────────────── 5.5 None △ 45 △ × Comparison 6.5 None ○ 45 △ × Comparison 7.5 None ○ 52 △ △ Comparison 8.5 None ○ 54 △ △ Comparison 5.5 Yes △ 50 △ △ Comparison 6.5 Yes ○ 63 ○ ○ 7.5 Yes ○ 65 ○ ◎ The present invention 8.5 Yes ○ 65 ○ ◎ The present invention ────────────────────────────── ─────

From the above results, it can be seen that the present invention provides an ink absorbing property,
It turns out that it is excellent in gloss and a surface crack.

Example 2 The polyolefin resin paper support of Example 1 was produced in the same manner as in Example 1. However, a polyolefin resin-coated paper having an SRa value of 3.5 was produced in place of a cooling roll having a silk-like shape. Other than that, all were tested according to Example 1. As a result, the same results as in Example 1 were obtained in terms of ink absorption, cracking, and breakage.

[0062]

According to the present invention, it is possible to provide an ink jet recording material which maintains high gloss and high ink absorbability and is prevented from cracking and breaking.

Claims (4)

[Claims] 1. An ink jet recording material comprising a polyolefin resin-coated paper support coated with an ink-receiving layer containing fumed silica, wherein the support has a water content of 6% or more, and An ink jet recording material comprising an undercoat layer on the surface of the body provided with the ink receiving layer. 2. The ink-jet recording method according to claim 1, wherein the surface of the support is finely roughened or molded so that an average surface roughness (SRa) of an ink receiving layer applied surface is 0.11 or more. Recording material. 3. An average particle diameter of primary particles of the fumed silica is 3 to 10 nm, and a specific surface area by BET method is 25.
Jet recording material according to claim 1 is 0 m ² / g or more. 4. The ink receiving layer according to claim 1, wherein the fumed silica is 10%.
To 30 g / m ² containing ink jet recording material according to claim 1, the hydrophilic binder to the fumed silica, containing 30 wt% or less.