JP2005186449A - Ink jet recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording material which uses, as a substrate, a resin coated paper sheet easily separable from pulp fibers in water finally, while maintaining a high ink jet performance. <P>SOLUTION: In the ink jet recording material having an ink receiving layer provided at least on one side of the resin coated paper sheet both sides of which are coated with resin layers, the resin layer is constituted of a mixture comprising polyolefin and an adhesion giving agent as requisite elements, and the ink receiving layer contains porous inorganic particulates crushed to a secondary particle size of 500 nm or less and polyvinyl alcohol. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording material, and more particularly, to an ink jet recording material in which consideration for the preservation of the global environment is enhanced.

  Inkjet recording has no noise and can be printed at high speed, and has been adopted rapidly for terminal printers in recent years. Also, by using a plurality of ink nozzles, it is easy to perform multicolor recording, and multicolor ink jet recording is performed by various ink jet recording methods. In particular, the use of an ink jet printer capable of forming a complex image quickly and accurately as a hard copy creation apparatus for image information such as characters, various figures and photographs created by a computer has attracted attention. Further, image information created by these computers is recorded on a transparent recording material by an ink jet printer, and this is also used as a manuscript for an OHP (overhead projector) or the like. In addition, as an application field of inkjet printers that have been developed in the future, the use of color printing in the printing field where image quality close to that of photographs is required, the output of design images in the design department, and the use of large inkjet plotters are simple. Large format posters, displays, flags, etc. that can be created. Furthermore, with the rapid spread of digital cameras in recent years, digital photographic images have become familiar and inkjet printers equipped with a photographic-only mode and ink for outputting these images with an inexpensive inkjet printer are also rapidly spreading.

  As a recording material used in the ink jet recording method, porous ink absorption was originally made of a pigment such as amorphous silica and a water-soluble binder such as polyvinyl alcohol on a support called ordinary paper or ink jet recording paper. Recording materials provided with layers have been used.

  However, when these conventional recording materials are used for photographs, block originals and design originals that require high resolution and gloss, there are some major problems. That is, a large amount of ink is driven to improve color developability, and the amount of ink partially varies depending on the pattern, so when the moisture derived from the ink penetrates the paper of the base layer, uneven swelling, so-called cockling occurs, Even after drying, the trace of the cockling remained, and the photo quality was lost.

  Therefore, an inkjet recording material using a support similar to a polyolefin resin-coated paper that has been widely used as a support for silver salt photographic printing paper in search of water resistance has been developed and is widely used as a photographic inkjet recording paper. . At that time, if only water resistance to the ink is a problem, it is sufficient to cover only the front side with a polyolefin resin. However, if the back side is also covered with a polyolefin resin, it may be accidentally contacted with water. In addition to being safe and reliable, a resin layer having similar physical properties is also provided on the back surface in the sense of maintaining the curl balance between the front and back.

  Prints using such photographic ink jet recording materials may be stored as they are, but some of them will be arranged as time comes. Especially in recent years, in combination with personal computers and image processing software, which has been widely used by ordinary households, trial printing is possible because you can freely trim, adjust the color tone, and select the composition and frame. In some cases, it becomes unnecessary immediately after printout.

  Conventional resin-coated paper is water-resistant and convenient for its original purpose, but once it is no longer needed, it is difficult to separate the resin and paper, so it could not be recycled even if recovered used paper . Accordingly, the development of an ink jet recording material that can be easily recycled while maintaining its original advantages has been a social request.

  As a support to meet such demands, a polyolefin coating made photopolymerizable by copolymerization of carbon monoxide and ethylene, or a polyethylene coating mixed with a biodegradable substance such as polycaprolactam or starch (for example, Patent Document 1) Have been proposed).

  However, even if the resin decomposes in a natural environment, this method is insufficient for recovering waste paper and separating the pulp and resin to recycle them.

  As a method of making the paper substrate itself water resistant, there is a proposal of a technique for making water resistant by applying a mixture of a vinyl alcohol polymer and an organic titanium compound (see, for example, Patent Document 2). There was a problem, and inconvenience occurred in terms of productivity when cast processing was performed to ensure gloss.

  An ink receptive layer that has water resistance and can be melt-extruded has been proposed (see, for example, Patent Document 3). However, in order to achieve the conflicting demands of ink receptivity and water resistance with a single layer, performance is improved. I had to be half-finished.

On the other hand, as a technology closely related to the present invention, there is a proposal of a moisture-proof paper (see, for example, Patent Documents 4 and 5) in which paper is coated with a mixture of polyolefin and a tackifier. However, these proposals do not suggest any disengageable ink jet recording material, and it is known that paper coated with a mixture of polyolefin and tackifier is used as a support for photographic printing paper or photographic ink jet recording material. It was not done.
JP 06-222500 A (2-3 pages) JP 2001-347754 A (2 pages) JP 09-216456 A (Example 3) JP 2002-220494 A JP 2001-192510 A

  Accordingly, an object of the present invention is to provide an ink jet recording material using a resin-coated paper as a support which can be easily separated from pulp fibers in water while maintaining high ink jet performance.

  1. In an ink jet recording material in which an ink receiving layer is provided on at least one surface of a resin-coated paper whose both surfaces are coated with a resin layer, the resin layer is made of a mixture containing polyolefin and a tackifier as essential elements, and the ink receiving material An ink jet recording material, wherein the layer contains porous inorganic fine particles pulverized to a secondary particle diameter of 500 nm or less and polyvinyl alcohol.

  2. 2. The ink jet recording material according to 1 above, wherein the resin layer further contains a compatibilizer.

  3. 3. The ink jet recording material according to 1 or 2 above, wherein the porous inorganic fine particles are any one of amorphous silica particles, alumina fine particles and hydrous alumina fine particles, or a combination thereof.

  4). 4. The ink jet recording material according to the above 1, 2 or 3, wherein the ink receiving layer on at least one surface is composed of a plurality of layers.

5). The In the resin-coated paper, inkjet recording material of the 1, 2, 3 or 4, wherein its base paper Cobb Size 20g / m ^2/30 seconds or more of the paper.

  6). 6. The ink jet recording material according to 1, 2, 3, 4 or 5, wherein the base paper accounts for 50% or more in the cross-sectional area of the resin-coated paper.

  By carrying out the present invention, it is possible to make a material advantageous for collecting used paper that can be easily disaggregated while maintaining optimum performance as a photographic ink jet recording material.

  Examples of the polyolefin used in the practice of the present invention include a homopolymer of propylene, a copolymer of propylene and ethylene or butene-1, or a mixture containing these as essential components. When two or more kinds of polypropylene resins are used in combination, it is preferable because of excellent disaggregation.

  Examples of tackifiers used in the practice of the present invention include aromatic or alicyclic petroleum resins, terpene phenol resins, aromatic modified terpene resins, rosin esters, hydrogenated alicyclic petroleum resins, hydrogenated terpene resins, Hydrogenated rosin esters are preferred. The ratio of the polyolefin and the tackifier used in the resin layer is 40:60 to 75:25, preferably 45:55 to 70:30.

  In the implementation of the present invention, the mixture containing polyolefin and tackifier as essential elements further includes a compatibilizer, a wax, an inorganic filler, a stabilizer such as an antioxidant, a viscosity adjusting agent, a lubricant, an antiblocking agent, An antistatic agent or the like may be added.

  Examples of the compatibilizer that can be advantageously used in the practice of the present invention include oxidized polyolefin, acid group-modified polyolefin such as polypropylene graft-modified with maleic anhydride, hydrogenated styrene-butadiene resin, polyolefin and styrene, crystalline polyolefin The amount used in the resin layer is 0 to 20 parts by mass, preferably 1 to 7 parts by mass.

  Examples of inorganic fillers that can be advantageously used in the practice of the present invention include calcium carbonate, mica, talc, silica, barium sulfate, kaolin, clay, and the like, and waxes include natural waxes such as plant-based, animal-based, and mineral-based ones. And synthetic waxes.

In the practice of the present invention, there are various methods such as a roll coater, a slot orifice coater, an extrusion coater, etc. as a method for applying the resin layer containing these polyolefin and tackifier as essential elements to the paper substrate. Depending on the scheme, it is advantageous. The layer may be a single layer or multiple layers. In the case of multiple layers, a co-extrusion method or a sequential extrusion method may be used. The coating amount of these resin layers is preferably about 10 to 40 g / m ^{2 for} each of the front and back sides.

  In the melt extrusion coating, the slit die is preferably a flat die such as a T-type die, an L-type die, a fishtail die, or a coat hanger type die, and the opening diameter of the slit is preferably 0.1 mm to 2 mm. . The multilayer coextrusion die type may be any type such as a feed block type, a multi-manifold type, and a multi-slot type. Moreover, although the temperature of a molten film is based also on the kind of resin, in the case of polyethylene, it is preferable that it is 280-340 degreeC. A so-called tandem method in which front and back processing is performed continuously is desirable.

  In the practice of the present invention, prior to providing these resin layers, the surface of the paper substrate is preferably subjected to an activation treatment such as corona discharge treatment or flame treatment.

The base paper for processing these resins is not particularly limited, and any of non-coat, coat, art, cast coat, etc. may be used. It is more preferable that the blending ratio of the hardwood pulp having a thin fiber diameter and the sulfite pulp having a soft fiber is high, and the paper sheet made from the pulp slurry beaten to an appropriate freeness is calendered. preferable. As the basis weight of the base paper, about 70 to 300 g / m ² is optimal as an ink jet recording material, but from the viewpoint of waste paper recovery and pulp fiber recycling, a resin that allows the processing liquid from the paper edge to penetrate easily. It is advantageous to design the base paper to occupy 50% or more, preferably 70% or more of the cross-sectional area of the coated paper.

As papermaking chemicals added to the pulp slurry, various sizing agents, dry strength agents, wet strength agents, fillers, yield improvers, pH adjusters, hue preparation dyes, pigments, fluorescent brighteners, etc. are optionally added. However, from the viewpoints of recovered paper and recycling of pulp fibers, it is not desirable to have a size that is too strong for the treatment liquid from the wood ends to penetrate easily, and for ease of fiber disaggregation. Too much wet strength is undesirable. Cobb size strength as the 10g / m ^2/30 seconds or more, preferably 20g / m ^2/30 seconds, or more preferably it is desirable to design the above 25g / m ^2/30 sec.

  Examples of the porous inorganic fine particles used in the ink receiving layer of the present invention include agglomerated silica such as gas phase method silica, precipitated silica and gel method silica, and aggregates of alumina hydrate such as boehmite and pseudoboehmite. What is necessary is just to select the inorganic particle of desired performance from the inside.

  These inorganic particles contain coarse particles as they are, and when used in an ink receiving layer, they are not only insufficient in gloss as a photographic ink jet recording material, but often feel rough.

  Therefore, it is desirable to use the pulverization and classification alone or in combination as inorganic particles having an optimum particle size. Examples of the pulverizer include a high-pressure homogenizer and a high-speed agitator mill. A high-speed agitator mill is more advantageous in terms of grinding efficiency.

  The high-speed agitator mill is a pulverizer having as essential components a bead, a vessel filled with beads, a stirring blade (disk) for stirring the beads, and a mechanism for separating the beads and the slurry after the pulverization treatment.

  The particle diameter of the beads is preferably in the range of 0.1 to 0.65 mm, preferably 0.2 to 0.4 mm, because the grinding efficiency is good.

The material of the beads is required to have a sufficiently high hardness, and typically includes ZrO ₂ or Al ₂ O ₃ having a purity of 90% or more. The filling rate is 50 to 95%, preferably 70 to 90% in bulk. A typical operating condition of the disk peripheral speed is 8 to 15 m / s.

  In a high-speed agitator mill, heat is generated, and if it is left as it is, the slurry temperature rises and the pulverization efficiency deteriorates due to a decrease in shearing force. Therefore, it is operated while cooling. Therefore, it is desirable that the vessel has a good thermal conductivity. Also, the vessel must withstand friction and the like. Because of such requirements, zirconia reinforced alumina is advantageous as a material.

  As the classifying device, a device that performs centrifugal separation by forced stirring is advantageous. Centrifugal force exceeding 10,000 G at maximum can be obtained by rotating baskets and other stirrers at high speed, so the classification point is said to be possible to around 100 nm. Examples include Microcut ECA1000, ECA2000, Nanocut NCS3000. (Above KRETTEK VERFAHRENSTECHNIK GMBH) High-G decanter, BDN type decanter (above Sakai Kogyo Co., Ltd.) and the like.

When pulverizing the agglomerated silica, it is advantageous to make a cationic dispersant coexist.
In a preferred embodiment of the present invention, the cationic dispersing agent coexisting at the time of pulverization is a polymer having a cationic site such as amine, ammonium salt, pyridinium salt, imidazoline, and a monomer having at least a cationic site and a vinyl unsaturated bond group as a polymerization component. A polymer containing cation sites may be used, or a polymer in which a cationic site is bonded to the polymer by an addition reaction. The molecular weight per cation value of the dispersant is preferably about 50 to 300.

  Among the cationic polymers, a cationic polymer having a structural unit of a polydiallylamine derivative is particularly preferable, and a structure represented by the following general formula (1), (2), (3) or (4) is used as a structural unit. It is a cationic polymer. These cationic polymers are commercially available as Charol DC902P (Daiichi Kogyo Seiyaku), Jetfix 30 (Satoda Chemical), and PAS (Nittobo Co., Ltd.).

In the general formulas (1), (2), (3) and (4), R ₁ and R ₂ each represents a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a substituted alkyl group such as a hydroxyethyl group. Y represents a radical polymerizable monomer (for example, sulfonyl, acrylamide and derivatives thereof, acrylic ester, methacrylic ester, etc.). Further, n / m = 9/1 to 2/8, and l = 5 to 10,000. X represents an anion.

  Specific examples of the polydiallylamine derivative represented by the general formula (3) or (4) include those containing a SO2 group as a repeating unit described in JP-A-60-83882, and JP-A-1-9776. And copolymers with acrylamide described in 1.).

  The addition amount of the dispersant is preferably in the range of 1 to 10% by mass with respect to silica, and preferably in the range of 2 to 6% by mass. By setting it within this range, the formation of fine silica particles is promoted, and the strength of the ink receiving layer can be maintained.

  The secondary particle size of the pulverized inorganic particles is 0.05 to 0.5 μm, preferably 0.08 to 0.3 μm, and more preferably 0.1 to 0.25 μm. This is desirable from the viewpoint of achieving both physical properties and surface gloss of the ink absorbing layer. The particle diameter of the inorganic fine particles referred to in the present invention is a weight average secondary particle diameter measured with a LA910 laser scattering particle size distribution meter manufactured by Horiba, Ltd.

  A binder or the like is added to the inorganic particle slurry to prepare a coating solution for an ink receiving layer. As binders, starch derivatives, cellulose derivatives, casein, gelatin, soybean protein, polyvinyl alcohol or derivatives thereof; polyvinylpyrrolidone, maleic anhydride resin, various polymer latexes or various polymer-containing monomers such as carboxy groups of various polymers Functional group-modified polymer latex; or various binders such as those obtained by cationizing various polymers with cationic groups.

  The hydrophilic binder preferably used in the ink receiving layer of the present invention is fully or partially saponified polyvinyl alcohol or cation-modified polyvinyl alcohol. Particularly preferred among the polyvinyl alcohols are those having a saponification degree of 80% or more or those that have been completely saponified, and an average degree of polymerization of 200 to 5000, preferably 500 to 4000, from the viewpoint of improving film formation and film brittleness. Is used. The cation-modified polyvinyl alcohol has a primary to tertiary amino group or a quaternary ammonium group in the main chain or side chain of the polyvinyl alcohol as described in, for example, JP-A-61-10383. Polyvinyl alcohol.

  The content of polyvinyl alcohol in the coating solution is preferably 10 to 35% by mass and more preferably 10 to 30% by mass with respect to the inorganic particles. Moreover, although other hydrophilic binders can be used in combination, it is preferably 20% by mass or less with respect to polyvinyl alcohol.

  In addition, an ink fixing agent, a binder crosslinking agent, an image preserving agent, a colorant, a thickener, a surfactant, and the like can be appropriately added to the ink receiving layer coating solution.

  In the present invention, the coating method of the ink receiving layer is not particularly limited, and a known coating method can be used. For example, there are a slide lip method, a curtain method, an extrusion method, an air knife method, a roll coating method, a rod bar coating method, and the like.

<Preparation of base paper>
Hardwood bleached kraft pulp was adjusted to a concentration of 4% by mass in water and beaten to a pulp fiber length of 0.6 mm and a Canadian standard freeness of 350 ml. After beating, 3 parts by weight of cationized starch, 0.2 parts by weight of anionized polyacrylamide, 0 parts by weight for the alkyl ketene dimer emulsion (as ketene dimer) and polyamine polyamide epichlorohydrin resin are used for 100 parts by weight of pulp. A paper slurry was prepared by adding two levels of (base paper a) and 0.2 parts by weight (base paper b), and adding appropriate amounts of fluorescent brightener, blue dye, and red dye. After that, a paper web is formed while giving an appropriate turbulence on a long paper machine running a paper slurry at 200 m / min, and the linear pressure is adjusted in the range of 15-100 Kgf / cm in the wet part. After performing the three-stage wet press, it was treated with a smoothing roll, followed by a two-stage tight press with a linear pressure adjusted in the range of 30 to 70 kgf / cm in the subsequent drying part, and then dried. Size press comprising 4 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 parts by weight of optical brightener, 0.002 parts by weight of blue dye, 4 parts by weight of sodium chloride, and 92 parts by weight of water during the drying process The liquid was pressed at a size of 25 g / m ² , dried to a final paper substrate moisture content of 8%, machine calendered at a linear pressure of 70 kgf / cm, and a density of 170 g / m ² basis weight. Base papers a and b of 1.04 g / cm ³ were produced.
The base paper a had a cobb size (30 seconds) of 100 g / m ² or more, and the base paper b was about 13 g / m ² . A base paper c was similarly prepared except that the basis weight of the base paper b was 55 g / m ² .

<Preparation of resin-coated paper>
After corona discharge treatment on the front and back surfaces of the base papers a, b and c, 40 parts by mass of amorphous polypropylene (mass average molecular weight 70000), 20 parts by mass of crystalline polypropylene (MFR = 38 g / 10 min, melting point 157 ° C.), A compound consisting of 40 parts by mass of a terpene phenol copolymer resin (softening point 145 ° C., acid value of 1 or less) and 1 part by mass of a hindered phenol antioxidant (melting point 110 to 125 ° C.) was extruded from a T-die at 200 ° C., respectively. The substrate of Example 1 was coated with a coating amount of 30 g / m ² .

<Preparation of inkjet recording material>
(Sample 1; the present invention)
Next, a coating liquid mainly composed of Fine Seal X37B (manufactured by Tokuyama Corporation, sedimentation method silica having a pore volume of 1.6 ml / g) is applied to the base paper a as inorganic particles at a coating amount of 20 g / m ² and dried. Sample 1 was obtained. At this time, the secondary particle diameter of the fine seal X37B was 400 nm.

  The coating liquid for inorganic particles is a Dynomill KDL-PILOT agitator mill (made by Willy A. Bachofen AG Maschinenfabrik) filled with 85% bulky zirconia beads with 0.3 mm inorganic particles, operated at a peripheral speed of 14 m / s. While passing twice, polyvinyl alcohol (PVA235, manufactured by Kuraray Co., Ltd., saponification degree 88%, average polymerization degree 3500) 15 parts by mass (net amount) per 100 parts by mass of the solid content of the pretreated inorganic particles, It was prepared by adding 3 parts by weight of boric acid (net amount) and 0.3 part by weight (net amount) of amphoteric surfactant (SWAM AM-2150, manufactured by Nippon Surfactant) in the form of a 10% solution.

<Ink absorbability>
Red, blue, green, and black solid printing with a commercially available inkjet printer (Canon, BJF-870). Immediately after printing, the amount of ink transferred onto the PPC paper by lightly pressing the PPC paper over the print section The degree of was observed visually. Overall evaluation was made according to the following criteria.
A: No transfer at all.
○: Slightly transferred but can be used.
Δ: Transfer and difficult to use.
X: Most of the images are transferred and cannot be used.

<Glossiness>
Immediately after creating the sample, the gloss of the recording sheet surface is visually determined.
A: Excellent gloss.
○: High gloss.
Δ: Slightly low gloss
X: Inferior in gloss

<Water resistance>
The sample was printed at 100% C, M, and Y using an ink jet printer (Epson PM800C), and the degree of cockling was visually determined.
A: Cockling is not seen at all.
○: Slight cockling is observed but there is no practical problem.
Δ: Cockling is seen and not practical.
X: Waves are intense and there is a head after rubbing.

<Ease of disaggregation>
In order to evaluate the ease of collecting recovered paper of each sample, 30 g of a sample cut into a 5 cm square was immersed in 1000 ml of cold water for 2 minutes and then stirred for 2 minutes with a mixer to observe the result.
A: The presence of the resin is not understood, and the fibers are unwound and dispersed.
○: The original resin remains, but the fibers are unwound and dispersed.
Δ: Some fibers are unwound and dispersed, but there are portions that retain the original shape.
X: The prototype is completely retained.
The results are shown in Table 1.

(Samples 2 and 3; the present invention)
DISPALAL 23N4-80 (manufactured by Sasol Japan Co., Ltd., boehmite type alumina having a pore volume of 0.4 ml / g, secondary particle diameter of 100 nm), DISPERAL HP14 / 2 (Sasol Japan Co., Ltd.) 2) Boehmite type alumina having a pore volume of 0.9 ml / g and a secondary particle size of 250 nm was used as samples 2 and 3, respectively. The evaluation results are also shown in Table 1.

(Samples 4 to 6; the present invention)
Fine seal X37B of sample 1 was prepared by using nip seal VN-3 (manufactured by Nippon Silica Co., Ltd., precipitated silica having a pore volume of 1.2 ml / g), nip gel CY-200 (manufactured by Nippon Silica Co., Ltd., pore volume 1). Samples 4 to 6 were used instead of 0.1 g / g gel method silica) and Nipgel AZ-201 (manufactured by Nippon Silica Co., Ltd., gel method silica having a pore volume of 2.0 ml / g) 20 g / m ² . The evaluation results are also shown in Table 1. At this time, the secondary particle diameters were 350 nm, 400 nm, and 400 nm, respectively.

(Samples 7 to 17; the present invention)
Samples 7 to 17 were prepared in the same manner as Sample 1 except that the content of the compound of Sample 1 was replaced with the composition shown in Table 1. The evaluation results are also shown in Table 1.

(Samples 18 and 19; the present invention)
Samples 18 and 19 were used in the same manner as Sample 1 except that the base paper a of Sample 1 was changed to base papers b and c, respectively. The evaluation results are also shown in Table 1.

(Sample 20; outside the present invention)
A sample 20 was prepared in the same manner as the sample 1 except that the inorganic fine particle fine seal X37B was pulverized once in the sample 1. The results are shown in Table 1. At this time, the secondary particle diameter was 600 nm.

(Sample 21; outside the present invention)
The resin coating of Sample 1 was applied to the back surface of the base paper a, 60 parts by mass of high-density polyethylene (density 0.96 g / m ³ , MFR 7.0 g / 10 min) and low-density polyethylene (density 0.918 g / m ³ , MFR 9. 0 g / 10 min) 40 parts by weight of the mixture was melt extrusion coated at a coating amount of 20 g / m ² , and then low density polyethylene (density 0.918 g / m ³ , MFR 9.0 g / 10 min) on the front side was 20 g / m. Sample 21 was prepared in the same manner as Sample 1 except that it was melt-extruded with a coating amount of ² . The results are shown in Table 1.

(Sample 22; outside the present invention)
Sample 22 was obtained in the same manner as Sample 1 except that the resin-coated paper of Sample 1 was replaced with the base paper a. The results are shown in Table 1.

The contents of each component in Table 1 are as follows: 1: amorphous polypropylene (mass average molecular weight 70000), 2: crystalline polypropylene (MFR = 38 g / 10 min, melting point 157 ° C.), 3: crystalline polypropylene (mass average molecular weight) 100,000, MFR 650 g / 10 min), 4: amorphous (propylene-butene 1) copolymer resin (mass average molecular weight 80000, softening point 110 ° C., Tg-26 ° C.), 5: low molecular weight polypropylene (solution viscosity average molecular weight 21000, melting point) 143 ° C., density 0.91 g / cm ³ ), 6: aromatic modified terpene hydrocarbon resin (C9 aromatic, softening point 125 ° C., acid value of 1 or less, molecular weight 800), 7: terpene phenol copolymer resin (softening) Point 145 ° C., acid value 1 or less), 8: hydrogenated alicyclic petroleum resin (softening point 135 ° C., molecular weight 860, acid value 0. ), 9: maleic anhydride-modified polypropylene (softening point 154 ° C., acid value 26, number average molecular weight 40000), 10: Tuftec H1052 (manufactured by Asahi Kasei Kogyo Co., Ltd.); hydrogenated polybutadiene becomes ethylene butylene polymer in continuous phase Thermoplastic elastomer obtained by block copolymerization of dispersed phases of polystyrene at both ends; styrene content 20% by mass, density 0.89 g / m ³ , MFR13), 11: Tuftec H1141 (manufactured by Asahi Kasei Corporation); hydrogenated polybutadiene Is a thermoplastic elastomer in which an ethylene butylene polymer is block copolymerized with a dispersed phase of polystyrene at both ends in a continuous phase; styrene content 30% by mass, density 0.91 g / m ³ , MFR 140), 12: Dynalon 1321P (JSR Corporation) Manufactured; Hydrogenated polybutadiene is ethylene butylene polymer There disperse phase block copolymerization thermoplastic elastomer both terminated polystyrene in a continuous phase; a styrene content of 10 wt%, a density ^{0.89g / m 3, MFR10),} 13: DYNARON 6200P (JSR (Co., Ltd.); hydrogenated Thermoplastic elastomer obtained by block copolymerization of a disperse phase in which the polybutadiene is an ethylene butylene polymer and the terminal is an olefin crystal (hydrogenated 1,4 polybutadiene); styrene content 0 mass%, density 0.88 g / m ³ , MFR 2.5), 14: polypropylene wax (softening point 154 ° C. penetration 1 or less, molecular weight 7000), 15: oxidized polyethylene wax (melting point 121 ° C., acid value 1.0 molecular weight 7000), 16: calcium carbonate ( Reagent grade 1; mass average particle diameter of 1 μm or less, 17: hindered phenol antioxidant (melting point 110) It is a 125 ℃).

In any of the inkjet recording materials of the present invention, the disaggregation property is improved while maintaining the inkjet performance. On the other hand, the sample 21 whose support is polyethylene-coated paper has no disaggregation property, and the sample 22 whose support is not resin-coated has severe cockling and has a problem in ink jet performance. The sample 20 in which the secondary particle diameter of the inorganic fine particles exceeds 500 nm has insufficient gloss. Samples in Cobb size of the invention sample 18 below 20g / m ^2/30 seconds, the sample 19 ratio is less occupied in the cross-sectional area base paper improve the defibration properties respectively slightly inferior.

Claims (6)

In an ink jet recording material in which an ink receiving layer is provided on at least one surface of a resin-coated paper whose both surfaces are coated with a resin layer, the resin layer is made of a mixture containing polyolefin and a tackifier as essential elements, and the ink receiving material An ink jet recording material, wherein the layer contains porous inorganic fine particles pulverized to a secondary particle diameter of 500 nm or less and polyvinyl alcohol. The ink jet recording material according to claim 1, wherein the resin layer further contains a compatibilizing agent. 3. The ink jet recording material according to claim 1, wherein the porous inorganic fine particles are any one of amorphous silica particles, alumina fine particles, and hydrous alumina fine particles, or a combination thereof. 4. The ink jet recording material according to claim 1, wherein the ink receiving layer on at least one surface is composed of a plurality of layers. 5. The ink jet recording material according to claim 1, wherein the base paper is a paper having a cob size of 20 g / m < ² > / 30 seconds or more. 6. The ink jet recording material according to claim 1, wherein the base paper accounts for 50% or more in the cross-sectional area of the resin-coated paper.