JPH11240243A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium having an excellent reproducibility of a highly minute image. SOLUTION: The ink jet recording medium comprises at least two recording layers each containing a xerogel porous pigment on a paper support. In this case, 25 to 75 wt.% of a pigment component contained in the layer near the support of the layers is a xerogel porous pigment having a specific surface area of 100 to 500 m<2> /g, and 75 to 25 wt.% is a non-xerogel pigment having a specific surface area of 100 m<2> /g or less.

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 system for recording on a recording medium using an aqueous ink, and more particularly to an ink jet recording medium excellent in ink absorbency and high precision image reproducibility.

[0002]

2. Description of the Related Art An ink jet recording system using an aqueous ink has a low noise at the time of recording, is easy to colorize, and is capable of high-speed recording. Applications to form printing and the like are being promoted. Because high-quality paper and coated paper used for general printing have poor ink absorption,
The printed ink remains on the paper surface without drying for a long time, and contaminates the apparatus and the continuously printed sheet or stains the image. In order to solve such a problem, it is possible to use a recording paper having a low degree of size (Japanese Patent Laid-Open No. 52-53012) or to impregnate a base paper containing a urea-formalin resin with a water-soluble polymer (Japanese Patent Laid-Open No. 53-
49113). Furthermore,
Recording papers coated with various kinds of porous inorganic pigments such as amorphous silica on the surface for the purpose of improving the color development and reproducibility of the ink (JP-A-55-51583, JP-A-56-51583)
148585). Further, in order to obtain a high-definition image in which bleeding is suppressed, the physical properties of these porous pigments are defined (JP-A-58-110287, JP-A-59-185690, JP-A-61-14158).
No. 4) has been proposed.

With the generalization of the ink jet recording method, the aim is to achieve both the suitability of office paper, such as writing with a pencil, and the suitability of recording, and Japanese Patent Application Laid-Open No. 4-16379 discloses that two types having different pore radii are used. It has been proposed to appropriately use the above-mentioned porous pigments, and a tentative result has been obtained. In recent years, the development of inkjet printer technology has been remarkable, and recently, those that almost match the image quality of silver halide photographs have been developed, but with the improvement in printer accuracy, phenomena that were not so often omitted until now, It has come to be regarded as a defect. One of these is a phenomenon called cockling.

When recording is performed on a recording medium having paper as a base material with an aqueous ink or the like, the recording medium may be uneven or wavy. This phenomenon is called cockling. When cockling occurs, the distance and angle of the recording head with respect to the recording medium partially change, and the intervals between the ejected ink droplets change and become uneven or displaced, so that the original recording accuracy cannot be obtained. As a result, the quality of the recorded matter is reduced. In the worst case, there is a problem in that the head collides with the uneven recording medium to stain the recorded image, the recording medium is broken, or the recording head is damaged.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording medium which can solve the above-mentioned drawbacks such as cockling and can record a high-definition image with good reproducibility. We use materials for recording media,
As a result of intensive studies on the layer structure, the properties of the base material mainly made of paper, and the processing method, it was found that an inkjet recording medium having excellent reproducibility of a high-definition image was obtained, and the present invention was completed. .

[0006] Cockling is considered to occur for the following reasons. That is, the moisture in the ink injected onto the recording medium penetrates to the base material, is absorbed by the pulp fiber of the base material, and swells the pulp fiber. It is well known that the expansion coefficient of pulp fiber due to water has a large difference between the axial direction of the fiber and the direction perpendicular thereto, and in most cases when the paper is machined, the fiber is oriented in the flow direction of the paper machine. ing. Therefore, the swelling ratio of the paper is larger in the width direction than in the flow direction of the paper machine, and anisotropy occurs in the swelling direction. In addition, the amount of ink to be applied to the recording medium is usually not the same over the entire surface, and there are few thin places and many dark places with the density gradation of the pattern. Will increase. Cock ring
Since it is considered that such a phenomenon is caused by the anisotropy of the swelling ratio and the unevenness of the swelling amount of the base material, it is extremely difficult to improve cockling for a recording medium using paper as the base material.

[0007]

The present invention includes the following aspects. [1] An ink jet recording medium in which at least two recording layers containing a xerogel-based porous pigment are provided on a paper support, and a pigment component contained in a recording layer of the recording layers which is close to the support. 25-75% by weight of specific surface area 1
00~500m a xerogel type porous pigment ² / g, an ink jet recording medium, characterized in that 75 to 25% by weight is non-xerogel pigment follows a specific surface area of 100 m ² / g. [2] The inkjet according to claim 1, wherein the density of the paper support measured by JIS P8118 is 0.85 g / cm ³ or more and 1.30 g / cm ³ or less, and the paper thickness is 100 μm or more and 300 μm or less. recoding media. [3] The ink jet recording medium according to claim 1 or 2, wherein the non-xerogel pigment is at least one selected from calcium carbonate and calcined kaolin.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The support of the present invention can be exemplified by paper, synthetic paper and resin film, but the paper support is excellent in ink absorbency, and in the case of paper, the cockling improvement effect of the present invention is remarkable. Therefore, paper is preferred in the present invention. As pulp for paper, softwood bleached kraft pulp (hereinafter, NB)
Chemical pulp such as KP) or hardwood bleached kraft pulp (hereinafter referred to as LBKP), mechanical pulp such as GP, BCTMP, MP, pulp obtained from non-wood materials such as kenaf, DIP
And other paper pulp typified by such pulp. Based on this, polyethylene, polypropylene, ethylene-propylene copolymer, polystyrene, ethylene
Polyolefin fibers such as vinyl acetate copolymer, polyvinyl chloride, halogen-containing polymers such as polyvinylidene chloride, 6-nylon, polyamide fibers such as 66-nylon, polyethylene succinate, polycaprolactone,
Aliphatic polyester fibers such as polylactic acid and polyhydroxybutyrate / valylate copolymer, and vinylon fibers may be mixed.

If necessary, talc, kaolin, calcined kaolin, calcium carbonate, white carbon, amorphous silica, diatomaceous earth, titanium oxide, activated clay, inorganic pigments such as barium sulfate, urea formalin resin, nylon powder, polyethylene powder The organic pigment can be prepared by a usual method using acidic or neutral papermaking by adding an organic pigment as a filler.

Further, sizing agents represented by rosin sizing agents, alkenyl succinic anhydrides, alkyl ketene dimers, etc., starches such as oxidized starch, enzyme-modified starch, cation-modified starch, esterified starch, etherified starch, etc. Methylcellulose, ethylcellulose, carboxymethylcellulose, methoxycellulose, hydroxycellulose, fully or partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, polyvinyl alcohols such as silicon-modified polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, acrylamide.
Water solubility of acrylic acid ester copolymer, acrylic acid amide / acrylic acid ester / methacrylic acid copolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, casein, etc. For latex of molecules, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylate, polybutyl methacrylate, styrene / butadiene copolymer, vinyl chloride / vinyl acetate copolymer, styrene / butadiene / acrylic copolymer, etc. Base paper to which a representative adhesive is internally added or applied can be used as appropriate.

[0011] The JIS P of the base paper thus obtained is
The density of the support as measured by 8118 is 0.85 g / c
m ³ or more, if it thereby being further cockling reduced, whereas, when the density exceeds 1.30, the paper occurs a phenomenon of clearing (Blanking) the appearance of the paper is impaired Therefore, it is not desirable depending on the purpose of use. Further, even when the density is within the above range, cockling is more unlikely to occur when the paper thickness is 100 μm or more, which is a more preferable embodiment. However, if the paper thickness exceeds 300 μm, there is a possibility that the paper feeding aptitude deteriorates depending on the printer. Therefore, JI
The density of the support as measured by SP8118 is 0.8
5 g / cm ³ or more and 1.30 or less are preferable, and the paper thickness is 10
It is preferably in the range of 0 μm or more and 300 μm or less. As a result, a recording paper having a good paper appearance and excellent paper feedability by a printer can be obtained. The method of adjusting the density of the support is not particularly limited, for example, adjusting the freeness of pulp used for making base paper, using a machine calender or a super calender, or the like at room temperature or high temperature. It can be adjusted to a target value by a pressure treatment.

The composition of the coating layer is two or more. The xerogel-based porous pigment which is preferable as the ink jet recording layer is a silica-based pigment, and the surface layer (upper layer) is preferably a xerogel-based porous pigment as a main pigment. The specific surface area of the xerogel-based porous pigment of the surface layer (upper layer) is not particularly limited, but is preferably, for example, 100 m ² / g or more. There is no particular upper limit, but for example, it can be easily obtained up to about 1000 m ² / g. The pigment of the recording layer (lower layer) close to the support is
It is necessary to use a xerogel-based porous pigment and a non-xerogel-based pigment in combination. Examples of the non-xerogel pigments include those described below, and calcined kaolin and calcium carbonate (including Callite KT, Callite SA, and the like under the trade name of aragonite, which is a columnar single crystal aggregated in an igashi shape) are preferable. Kaolin is preferred.

In the present invention, the pigment of the recording layer (lower layer) close to the support is a non-xerogel pigment having a specific surface area of 100 m ² / g or less in an amount of 75 to 25% by weight.
Remaining 25 to 75% by weight of specific surface area of 100 to 500 m ²
/ G xerogel-based porous pigment. The non-xerogel pigment preferably has a specific surface area of 60 m ² / g or less. If the xerogel-based porous pigment in the recording layer close to the support is less than 25% by weight, the absorption capacity of the ink decreases, and the solvent component in the ink that cannot be retained is absorbed by the base material, and the base fiber is removed. Cockling becomes defective due to swelling. Alternatively, the ink that could not be retained remains in the upper layer, and the absorption capacity of the ink is insufficient, and the image quality deteriorates due to poor bleeding, the ink absorption speed decreases, and the roll inside the printer or the next recorded material Or the likelihood of becoming dirty. In order to avoid these drawbacks while the xerogel-based porous pigment is less than 25%, it is necessary to greatly increase the total coating amount of the recording layer. A large coating amount is not only disadvantageous in terms of operation and economy, but also tends to lower the recording density and surface strength, which is not preferable in terms of quality. On the other hand, if the content is more than 75% by weight, there is no problem with cockling, but the water absorption of the lower layer is too large, so that the water retention of the paint of the upper layer (surface layer) is relatively reduced. Operational defects such as scratches and uneven coating tend to cause defects in appearance.

The xerogel-based porous pigment contained in each recording layer is a xerogel obtained by removing a solvent from a solid (gel) formed in a state of being dispersed in a sol form in a liquid medium and drying the solvent. Is a porous pigment obtained by pulverizing and classifying the particles. Aggregate (settling) pigments obtained by a recrystallization method or the like, and porous pigments obtained by sintering or the like are not included. Examples of xerogel-based porous pigments include: (1) a hydrogel-forming substance such as aluminum hydroxide, alumina, silica, or magnesium oxide as a raw material, and drying such hydrogel to form a xerogel, followed by pulverization;
Classification method. (2) In the state of a hydrogel, granules are formed into appropriate secondary and tertiary agglomerates, dried, and further heated to promote sintering, crystallization, etc., so that oxide primary particles A method of using with strengthened bonding. (3) At the stage of producing urea-formalin resin, melamine-formalin resin, etc. in a suspension of fine particles such as colloidal silica, colloidal alumina, etc., the production conditions are adjusted to produce the desired secondary particle diameter. A method in which, after being formed into fine particles, they are dried and then used as sintered particles as necessary. And the like, and are commercially available. Among the xerogel pigments, amorphous silica has a relatively small refractive index, and a property such as easy control of the porous structure allows a high recording density to be obtained.
Furthermore, it is particularly preferably used because it enables an ink jet recording medium having excellent ink receptivity.

As the pigment contained in the recording layer, in addition to the xerogel-based porous pigment, if necessary, for example, calcium carbonate, kaolin, calcined kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc carbonate, Inorganic pigments such as satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, white carbon, alumina, aluminum hydroxide, etc., styrene-based, acrylic-based, urea-based, melamine-based, benzoguanamine-based organic pigments, etc. A non-xerogel pigment or a pigment other than the specific xerogel porous pigment can also be used in combination.

Further, as a binder, starch and its derivatives, natural or semi-synthetic polymers such as carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soybean protein, polyvinyl alcohol and cation-modified polyvinyl alcohol, silyl-modified polyvinyl alcohol, etc. Modified polyvinyl alcohol, polyvinyl butyral resin, polyethylene imine resin, polyvinyl pyrrolidone resin, poly (meth) acrylic acid resin,
Acrylic ester resin, polyamide resin, polyacrylamide resin, polyester resin, urea resin, melamine resin, styrene / butadiene copolymer, methyl methacrylate / butadiene copolymer, vinyl such as ethylene / vinyl acetate copolymer A known material such as an aqueous solution or dispersion of a system copolymer resin or a modified polymer obtained by introducing an anionic or cationic residue into the above resins can be used as appropriate.

Further, for the purpose of improving the water resistance of a printed image with an aqueous ink, a polyethyleneimine resin, a polyamine resin, a polyamide resin, a polyamide epichlorohydrin resin, a polyamine epichlorohydrin resin, a polyamide polyamine epichlorohydrin resin,
Cationic polymer compounds such as polydiallylamine resins and dicyandiamide condensates can also be used in combination. Further, if necessary, a pigment dispersant, a thickener, an antifoaming agent, a foam inhibitor,
Foaming agents, release agents, penetrants, wetting agents, thermal gelling agents, lubricants,
Other various auxiliaries known in the art can also be used.

The coating amount is not particularly limited, and can be determined according to the required recording quality. Cockling poses a problem particularly when a high-quality printed matter is required. For this purpose, the total coating amount is preferably about 12 g / m ² or more and about 40 g / m ² or less. If the coating amount is small, it may be difficult to obtain a recorded matter having high accuracy and excellent image reproducibility, and conversely, even if the coating amount is large, the recording density and the surface strength may be reduced.

As described above, an amorphous silica pigment is particularly preferred as the xerogel-based porous pigment used in the ink jet recording layer, and the surface layer is preferably composed of the main pigment. However, in order to obtain the effects of the present invention, it is necessary to use a xerogel-based porous pigment and a non-xerogel-based pigment in combination as a recording layer having two or more layers and a single layer of pigment near the support.

The means for coating the ink receiving layer may be any of commonly used coating means such as a size press, a gate roll, a roll coater, a bar coater, an air knife coater, a rod blade coater, a blade coater, a curtain coater and a die coater. It can be selected as appropriate. Among them, a pre-metering type coating head such as a curtain coater or a die coater is particularly preferably used because a coating layer having a uniform thickness can be obtained.

The aqueous ink used in the present invention contains at least one of a water-soluble direct dye and a water-soluble acid dye as a dye. Contains fungicides and the like. Examples of the water-soluble direct dye include CI. Direct Black, CI. Direct Yellow, CI. Direct Blue, CI. Direct red and the like, and examples of the water-soluble acid dye include CI.
Acid Black, CI. Acid Yellow, CI. Acid Blue, CI. Acid Red and the like can be mentioned, but it is not necessarily limited to these.

[0022]

The present invention will be described in more detail with reference to the following examples, but it should be understood that the present invention is by no means restricted to these examples. In the examples, parts and% mean parts by weight and% by weight. The methods for measuring various physical properties in the examples are shown below. Recording density Seiko Epson inkjet printer PM-
Printing was performed at a recording density of 720 dpi using 700C, and the printing density was measured. As a result, those which exhibited excellent print density were ranked A, those which were slightly thin but had no practical problems, and those which were too thin to withstand practical use were ranked C.

Print drying property Inkjet printer PM- manufactured by Seiko Epson Corporation
Printing at 100% density was performed at a recording density of 720 dpi using 700C, and the dry state of the portion was visually evaluated, and the time until the gloss disappeared was used as a measure of print dryness. A indicates that the gloss disappears within a few seconds after discharge, A indicates that the gloss remains for several tens of seconds but has no practical problem, and C indicates that the gloss remains for more than 2 minutes and may cause a practical problem. Ranked.

Smear Inkjet printer PM- manufactured by Seiko Epson Corporation
200% density printing was performed at a recording density of 720 dpi using 700C, and the bleeding state of adjacent portions was visually evaluated. As a result, those with little bleeding were rated A, those with some bleeding but no practical problem were rated B, and those with too much bleeding and were not practical.

Cockling Inkjet printer PM- manufactured by Seiko Epson Corporation
200% density printing was performed at a recording density of 720 dpi using 700C, and the occurrence of cockling was visually evaluated. As a result, a case where cockling was not recognized at all was A, a case where cockling was slightly recognized but there was no practical problem was B, and a case where cockling was large was C.
And ranked.

Show-through Seiko Epson inkjet printer PM-
200% density printing was performed at a recording density of 720 dpi using 700C, and the occurrence of show-through was visually evaluated. As a result, those showing no show-through were ranked A, those showing some show-through but no practical problem were ranked B, and those showing severe show-through were ranked C.

Example 1 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was performed by a long net paper machine in a conventional manner to obtain a paper having a basis weight of 144 g / m ² . The coating amount after drying the ink receiving layer coating liquid (formulation 1) on one side of high quality paper (thickness: 150 μm, density: 0.96 g / cm ³ ) is 9 g / m ^2.
Coating and drying using a myr bar to form a lower recording layer, and then a coating liquid for ink receiving layer (formulation 2)
So that the coating amount after drying is 13 g / m ^2.
An upper recording layer was formed by coating and drying using a bar to obtain an ink jet recording medium. Formulation 1 Calcium carbonate (specific surface area 11.9 m ² / g, trade name: Brilliant-15, manufactured by Shiraishi calcium) 30 parts Amorphous silica (specific surface area 270 m ² / g, trade name: Fine Seal X-37, manufactured by Tokuyama) 70 parts Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray) 5 parts SBR latex (trade name: JSR0617, manufactured by Asahi Kasei) 10 parts

Formula 2 Amorphous silica (specific surface area: 270 m ² / g, trade name: Fine Seal X-37, manufactured by Tokuyama) 100 parts Polyvinyl alcohol (trade name: R-1130, manufactured by Kuraray) 20 parts Polydiallyldimethylammonium chloride -Based cationic resin (trade name: PAS-H-5L, manufactured by Nitto Boseki) 5 parts

Example 2 The pigment ratio of the formulation 1 used in Example 1 was changed to calcium carbonate 5
An ink jet recording medium was obtained in the same manner as in Example 1, except that 0 parts and 50 parts of amorphous silica were used.

Example 3 The pigment ratio of the formulation 1 used in Example 1 was changed to calcium carbonate 7
An ink jet recording medium was obtained in the same manner as in Example 1 except that 0 parts and 30 parts of amorphous silica were used.

Comparative Example 1 The pigment ratio of Formulation 1 used in Example 1 was changed to calcium carbonate 8
An ink jet recording medium was obtained in the same manner as in Example 1, except that 0 parts and 20 parts of amorphous silica were used. Comparative Example 2 An ink jet recording medium was obtained in the same manner as in Example 1 except that the following formulation 3 was used instead of the formulation 1 used in the example 1. Formulation 3 Calcium carbonate (specific surface area: 31.4 m ² / g, trade name: Callite KT, made of Shiraishi calcium) 80 parts Amorphous silica (specific surface area: 270 m ² / g, trade name: Fine Seal X-37, manufactured by Tokuyama) 20 Part Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray) 5 parts SBR latex (trade name: JSR0617, manufactured by Asahi Kasei) 10 parts

Example 4 An ink jet recording medium was obtained in the same manner as in Example 1 except that the following formulation 4 was used instead of formulation 1 used in example 1. Formulation 4 Calcined kaolin (specific surface area: 15.3 m ² / g, trade name: Ansilex, manufactured by Angel Hard) 30 parts Amorphous silica (specific surface area: 260 m ² / g, trade name: Carplex FPS-101, manufactured by Shionogi & Co., Ltd.) ) 70 parts Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray) 5 parts SBR latex (trade name: JSR0617, manufactured by Asahi Kasei) 10 parts

Comparative Example 3 The ratio of the pigment of Formula 4 used in Example 4 was changed to calcined kaolin 20.
And an ink jet recording medium was obtained in the same manner as in Example 4 except that 80 parts of amorphous silica was used. Comparative Example 4 The ratio of the pigment of Formulation 4 used in Example 4 was changed to calcined kaolin 80.
Parts, and 20 parts of amorphous silica, to obtain an ink jet recording medium in the same manner as in Example 4.

Comparative Example 5 An ink jet recording medium was obtained in the same manner as in Example 1 except that the following formulation 5 was used instead of formulation 1 used in example 1. Formulation 5 Calcium carbonate (specific surface area 11.9 m ² / g, trade name: brilliant-15, made of calcium shiraishi) 30 parts amorphous silica (specific surface area 700 m ² / g, trade name: thyricia # 770, manufactured by Fuji Silysia Chemical) 70 parts Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray) 5 parts SBR latex (trade name: JSR0617, manufactured by Asahi Kasei) 10 parts

Example 5 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was performed by a long net paper machine by a conventional method. Performed pressurization treatment (4 times) with a calender and weighed 145.2 g
/ M ² high quality paper (thickness 165 μm, density 0.88 g / c
An ink jet recording medium was obtained in the same manner as in Example 1 except for using m ³ ). Example 6 Canadian Standard Freeness 450cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was performed in a long net paper machine by a conventional method, using a super calender having a linear pressure of 120 kg / cm. Performs pressure treatment (6 times) and weighs 105.8 g
/ M ² high-quality paper (108 μm thick, density 0.95 g / c
An ink jet recording medium was obtained in the same manner as in Example 1 except for using m ³ ).

Example 7 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was carried out using a fourdrinier paper machine by a conventional method. Performed pressurization treatment (4 times) with a calender and weighed 145.2 g
/ M ² high quality paper (thickness 165 μm, density 0.88 g / c
An ink jet recording medium was obtained in the same manner as in Example 1 except for using m ³ ).

Example 8 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was performed by a long wire paper machine in a conventional manner. Pressure treatment (2 times) by calender and basis weight of 128.7 g
/ M ² high quality paper (thickness 165 μm, density 0.78 g / c
An ink jet recording medium was obtained in the same manner as in Example 1 except for using m ³ ).

Example 9 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was carried out by a fourdrinier paper machine by a conventional method, and the linear pressure was 120 kg / cm. 80 ℃
In the same manner as in Example 1 except that a high-quality paper (thickness: 170 μm, density: 1.33 g / cm ³ ) was subjected to pressurization (8 times) using a super calender, and the basis weight was 226.1 g / m ^2. An ink jet recording medium was obtained.

Example 10 Canadian Standard Freeness Additives such as alkyl ketene dimer, sulfate band and cationized starch were added to 450 cc hardwood pulp, and papermaking was carried out by a long wire paper machine in a conventional manner. Pressurized by calender (4 times) to reduce density to 0.95g
An ink jet recording medium was obtained in the same manner as in Example 1 except that high-quality paper (thickness: 95 μm, density: 0.95 g / cm ³ ) adjusted to / cm ³ and having a basis weight of 90.3 g / m ² was used.

Example 11 Canadian Standard Freeness 450 cc hardwood pulp was added with additives such as alkyl ketene dimer, sulfate band, and cationized starch, and papermaking was carried out by a long net paper machine in a conventional manner. Pressurized by calender (4 times) and weighed 283.2g
/ M ² high-quality paper (thickness 311 μm, density 0.91 g / c
An ink jet recording medium was obtained in the same manner as in Example 1 except for using m ³ ). Table 1 shows the results of evaluating the recording density, print drying property, bleeding, cockling, and show-through for the above 15 types of recording media. In the eleventh embodiment as well, a paper feed failure occurred occasionally in the printer, but it was not shown in Table 1 because the frequency was practicable.

[0041]

[Table 1]

[0042]

As is clear from Table 1, the examples of the present invention are ink jet recording media which are excellent in all of the recording density, print drying property, bleeding, cockling and show-through as compared with the comparative example. Further, in the present invention, an ink jet recording medium having excellent reproducibility of a high definition image can be obtained.

Claims (3)

[Claims] 1. An ink jet recording medium comprising at least two recording layers containing a xerogel-based porous pigment on a paper support, and a pigment contained in a recording layer of the recording layers close to the support. 25 to 75% by weight of the component is a xerogel type porous pigment having a specific surface area of 100 to 500 m ² / g, and 75 to 25% by weight is a non-xerogel type pigment having a specific surface area of 100 m ² / g or less. Ink jet recording medium. 2. The paper support has a density measured by JIS P8118 of 0.85 g / cm ³ or more and 1.30 g / c.
m ³ or less, the ink-jet recording medium according to claim 1, wherein the sheet thickness is equal to or is 100μm or more 300μm or less. 3. The ink jet recording medium according to claim 1, wherein the non-xerogel pigment is at least one selected from calcium carbonate and calcined kaolin.