JP2000001045A - Ink jet recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording body which is excellent in ink jet recording property, is excellent in the absorbency of ink, and also, is excellent in printed face smoothness after printing, and dimensional stability, and by which cockling does not occur. SOLUTION: For this ink jet recording body wherein at least one layer of a recording layer is provided on a base material, the base material is a porous synthetic resin film sheet, and also, the cup water absorption (JIS P8140) is 10 g/m2 or higher. Especially, the Stoeckigt sizing degree (JIS P8122) of the base material is preferably 500 sec or lower. Also, the synthetic resin which constitutes the porous synthetic resin film sheet is preferably a polyolefin resin.

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 paper having excellent suitability for ink jet recording, and has excellent ink absorbency, excellent printing surface smoothness and dimensional stability after printing, and does not cause cockling. The present invention relates to an inkjet recording sheet.

[0002]

2. Description of the Related Art An ink jet recording system using an aqueous ink or the like has 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. Fine paper and coated paper used for general printing have poor ink absorbency, and thus are impractical because they contaminate printed sheets and stain images. In order to solve such a problem, it is possible to use a recording paper having a low size,
JP-A-532012), a recording medium obtained by impregnating a water-soluble polymer into base paper internally containing a urea-formalin resin (Japanese Patent Application Laid-Open No.
-49113) and the like. In addition, ink
Recording paper coated with various porous inorganic pigments such as amorphous silica on the surface for the purpose of improving the color development and reproducibility of the recording paper (JP-A-55-51583, JP-A-56-14)
No. 8585). Further, for the purpose of obtaining a high-definition image in which blurring is suppressed, a recording medium or the like in which the physical properties of these porous pigments are specified in a specific range (Japanese Patent Application Laid-Open No. 58-110)
287, JP-A-59-185690, and JP-A-61-141584).

[0003] In recent years, the development of ink jet printer technology has been remarkable, and in recent years, those having almost the same image quality as silver halide photographs have been developed. The phenomenon has become a new problem. One of these is a phenomenon called cockling. When recording is performed with a water-based ink or the like on a paper-based recording catalyst, the recording medium may be uneven. This phenomenon is called cockling. When cockling occurs, the distance of the recording head to the recording medium partially changes, the interval between the ejected ink droplets changes, and the original recording accuracy cannot be obtained due to irregularity or displacement, As a result, the quality of the recorded matter decreases. In the worst case, the head collides with the uneven recording medium, which may cause a problem that the recorded image is stained, the recording medium is broken, or the recording head of the printer is damaged.

[0004] In order to solve these problems, even if ink jet paper is manufactured using a water-resistant, less stretchable film sheet as a base material and printing is performed with aqueous ink, cockling does not occur. Some ideas have been proposed. However, when such a film sheet is used, the ink absorbency of the base material itself is inferior, so that the occurrence of cockling can be suppressed, but there is a problem that bleeding or the like easily occurs in a printed image.

[0005] Furthermore, since the printed image of the printer has become closer to a silver halide photograph, the development of a glossy inkjet paper that gives a glossy surface to the ink jet paper and makes the printed image more similar to a silver halide photograph has been developed. I'm advancing.

As a gloss type ink jet paper, an ink receiving layer made of a hydrophilic polymer resin such as starch, a water-soluble cellulose derivative, polyvinyl alcohol and polyvinyl pyrrolidone is mainly provided on a base material such as a plastic film or paper. A recording medium has been proposed. In order to obtain such an ink-jet paper having the transparency or gloss of the coating layer, JP-A-59-174381, JP-A-60-92849, and JP-A-60-14.
5879, JP-A-60-220750, JP-A-60-224578, JP-A-61-3278
No. 8 has been proposed.

[0007] Even in such glossy ink jet paper having a hydrophilic polymer resin as an ink receiving layer, when a plastic film is used as a base material, cockling can be suppressed, but blurring occurs in print quality, In addition, even when a highly absorbent paper is used as the base material, there is a problem that the occurrence of cockling is unavoidable although the print quality is good.

[0008] As another type of glossy inkjet paper, there has been proposed a so-called cast type glossy inkjet paper which is pressed against a heated mirror drum while the coating layer is in a wet state and dried to finish. As such a cast type glossy inkjet paper, the present inventors have proposed a cast containing a copolymer resin having a glass transition point as a main component on a base paper provided with an undercoat layer containing a pigment and an adhesive as a main component. It has been found that a cast paper for ink jet recording having both excellent gloss and ink absorbability can be obtained by forming a coating layer and performing a cast finish, and proposed as JP-A-7-89220. However, even in cast paper for ink jet recording, cockling is inevitable since the paper is used as a base material. However, when using a plastic film as the base material to suppress cockling on cast glossy paper, the cast surface is roughened by the steam generated when the cast coating solution is dried on the cast drum. This leads to a problem that the quality and the operability are reduced. The reason why the glossiness is lowered by the water vapor during drying is that the casting method forms a coating liquid containing a pigment and an adhesive as a main component on a paper support, and a mirror surface in a wet state. This is a method of obtaining a smooth and glossy inkjet paper by pressing against a heated cast drum surface having a mirror surface and transferring a mirror surface to a coating layer. The moisture in the wet coating layer cannot evaporate to the finished surface side because the coating layer is in close contact with the heated cast drum surface, and unlike the drying in normal inkjet paper manufacturing, it is not all evaporated and dried through the base paper layer. must not.

As described above, it is difficult to satisfy both the elimination of cockling and the print quality such as bleeding, regardless of the general inkjet paper or the glossy type inkjet. At present, it is difficult to manufacture an ink jet recording paper which exhibits gloss by using a plastic film as a base material in order to suppress cockling while sacrificing print quality.

Japanese Patent Application Laid-Open No. Hei 2-253881 proposes a method for producing a cast printing film sheet using a microporous synthetic resin film sheet as a base material. When printing is performed on such a film sheet by an ink jet printer, the ink absorption speed is low and bleeding is remarkable.

[0011]

DISCLOSURE OF THE INVENTION The present invention relates to an ink-jet recording which is excellent in ink-jet recording suitability, excellent in ink absorption, excellent in printing surface smoothness and dimensional stability after printing, and in which cockling does not occur. Provide body. Further, the present invention provides an inkjet recording cast paper having excellent printing quality and excellent gloss.

[0012]

The present invention includes the following aspects. [1] In an ink jet recording medium in which at least one recording layer is provided on a base material, the base material is a microporous synthetic resin film sheet, and the Cobb water absorption (JIS P814)
0) is 10 g / m ² or more. [2] The degree of Sechigt sizing of the substrate (JIS P812
(2) The ink jet recording material according to [1], wherein the time is 500 seconds or less. [3] The ink jet recording material according to [1] or [2], wherein the synthetic resin constituting the microporous synthetic resin film sheet is a polyolefin resin. [4] The recording layer, or the gloss layer provided with a gloss layer on the recording layer, is pressed against a heated mirror-surface drum, dried and finished, [1], [2] or [3]. ] The ink-jet recording medium described above. [5] The air permeability of the substrate (JIS P8117) is 25
[1], [2],
[3] The ink jet recording medium according to [4]. [6] The ink jet recording medium according to [1], wherein the substrate has a through hole.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Materials for a microporous synthetic resin film sheet used as a base material include polyethylene, polypropylene, polybutene, polystyrene, polymethylpentene, ethylene / propylene copolymer, ethylene / butylene copolymer, propylene・ Polyolefin resin polymer such as butene copolymer, polyvinylidene fluoride, fluororesin polymer such as polytetrafluoroethylene,
A simple substance or a mixture of polyurethane, phenolic polyether, cellulose acetate, acrylonitrile polymer, amide resin, polyester resin and the like can be exemplified.
Among the above materials, polyethylene, polypropylene,
Polyolefin resin-based polymers such as polybutene, polystyrene, polymethylpentene, ethylene-propylene copolymer, ethylene-butylene copolymer, propylene-butene copolymer, and polyethylene terephthalate are relatively inexpensive, and are made porous in production. Easy and preferred.

As a method for making the film sheet porous, 1) stretching the film in a uniaxial or biaxial direction may be mentioned. In this case, inorganic fillers such as calcium carbonate, kaolin, talc, titanium oxide, silica, diatomaceous earth, and zinc oxide, and polyamides such as 6-nylon and 6,6 nylon (polytetrafluoroethylene, A fluorine-based resin such as an ethylene-6-fluoropropylene copolymer), a silicone resin, a phenol resin, a benzoguanamine resin, or a crosslinking agent such as styrene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, and divinylbenzene. When synthetic resin particles such as a copolymer of the above are used alone or in combination, a plurality of particles are likely to be porous. 2) A method in which an inorganic filler such as calcium carbonate, kaolin, talc, titanium oxide, silica, diatomaceous earth, and zinc oxide is blended in a film sheet, and the filler is eluted with an acid or the like to make it porous. Are also mentioned. Further, the methods 1) and 2) can be used in combination.

It is possible to adjust the pore size of the microporous synthetic resin film sheet by the degree of stretching and the particle size of the filler, but in any case, the penetration from the film surface to the inside, more preferably to the back surface. The through holes have a function of absorbing the water-based ink, and more preferably have a gas permeability.

When the microporous synthetic resin film sheet is used as a base material for ink-jet paper, the present inventors consider that the Cobb water absorption (JIS P81)
40, with a contact time of 120 seconds). The Cobb water absorption (JIS P8140) needs to be 10 g / m ² or more, preferably 20 g / m ² or more, more preferably 30 g / m ² or more. Although there is no particular upper limit, it is, for example, about 200 g / m ² . Cobb water absorption (JIS P
8140) finds that when it is 10 g / m ² or more, an ink jet paper having excellent quality as a base material of an ink jet paper, that is, excellent ink absorbency, excellent printability without bleeding, and no cockling can be obtained. Was. In addition, due to the above-mentioned quality, the degree of Stigcht size of the substrate (JIS P
8122) is more preferably 500 seconds or less. The Stekigt sizing degree is preferably not more than 400 seconds.

In general, the stekigt sizing degree increases as the rice tsubo or paper thickness increases, and the Cobb water absorption decreases as the rice tsubo or paper thickness decreases. In the present invention, irrespective of the basis weight or thickness of the base material, it is sufficient that the Cobb water absorption is within the above range.However, from the viewpoint of easy handling and manufacture of the product, the paper thickness is generally It is in the range of about 10 to 1000 μm, and more preferably in the range of 50 to 500 μm. In the case of a glossy inkjet paper of a cast system described later, when the air permeation amount (JIS P8117) of the base material becomes 2500 seconds or less, when drying on the cast drum, the water vapor of the coating layer passes through the base material. It is preferable because it is easy to come off and the gloss and the operability are improved.

The coating layer provided at least one layer on the substrate will be described. First, as pigments to be contained in a coating layer of a general inkjet paper and a cast type glossy inkjet paper, amorphous silica (including colloidal silica), zeolite, kaolin, clay, calcined clay,
Zinc oxide, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, sepiolite, smectite, synthetic smectite, hydrotalcite, magnesium silicate, magnesium carbonate,
Various pigments known and used in the general coated paper manufacturing field, such as magnesium oxide, diatomaceous earth, styrene-based plastic pigment, urea resin-based plastic pigment, and benzoguanamine-based plastic pigment, can be exemplified, and can be used alone or in combination. Among these, amorphous silica, zeolite, and aluminum oxide are preferable from the viewpoint of ink absorption, and it is particularly preferable to include amorphous silica as a main component of the pigment. As the amorphous silica, synthetic amorphous silica is preferable. As the amorphous silica, synthetic amorphous silica is preferable. Synthetic amorphous silica is roughly classified into a wet method and a dry method according to its production method. The wet method is obtained by using sodium silicate as a raw material and neutralizing with an acid to precipitate silica. The wet method is further divided into a precipitation method and a gelation method. The dry method is obtained by using silicon tetrachloride as a raw material, burning it with hydrogen and oxygen, and depositing silica. Usually, it is called white carbon, and is known as silicic anhydride, hydrated silicic acid, and the like. The average secondary particle diameter of the synthetic amorphous silica is preferably about 0.5 to 20 μm.

Examples of the adhesive include proteins such as casein, soybean protein, and synthetic protein; various starches such as starch and oxidized starch;
Polyvinyl alcohol, cellulose derivatives such as carboxymethylcellulose and methylcellulose, styrene-butadiene copolymer, conjugated diene-based polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, vinyl such as ethylene-vinyl acetate copolymer Conventionally known adhesives generally used for coated paper, such as a polymer latex, may be used alone or in combination.

The amount of the adhesive is not particularly limited, but is adjusted in the range of 1 to 100 parts by weight, more preferably 2 to 50 parts by weight, per 100 parts by weight of the pigment. If the amount of the adhesive is small, the strength of the recording layer may be weakened, the surface may be easily damaged, and powder may fall off. Conversely, if the amount of the adhesive is large, the ink absorbency may decrease, and the desired inkjet recording suitability may not be obtained.

The recording layer may contain a cationic compound for the purpose of fixing the dye component in the ink, increasing the printing density and imparting printing water resistance. Examples of the cationic compound include a cationic resin and a low molecular weight cationic compound (for example, a cationic surfactant or the like). A cationic resin is preferred from the viewpoint of improving the print density, and can be used as a water-soluble resin or an emulsion. Further, it can be used as a cationic organic pigment in which the cationic resin is insolubilized by means of crosslinking or the like to form a particulate form. Such a cationic pigment, when polymerizing a cationic resin, copolymerizes a polyfunctional monomer to form a crosslinked resin, or has a reactive functional group (hydroxyl group, carboxyl group, amino group, acetoacetyl group, etc.). A cross-linking agent is added to the cationic resin as needed, and the cross-linked resin is formed by heat, radiation, or the like. Cationic compounds, especially cationic resins, may also serve as adhesives.

The following are examples of the cationic resin. Specifically, 1) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, 2) acrylic resin having a secondary amine group, tertiary amine group, or quaternary ammonium group, 3)
Polyvinylamine, polyvinylamidines, 4) dicyan cation resin represented by dicyandiamide-formalin polycondensate, 5) polyamine cation resin represented by dicyandiamide-diethylenetriamine polycondensate, 6) epichlorohydrin-dimethylamine addition polymer , 7) dimethyldiallylammonium chloride-S
0 ₂ copolymer, 8) diallylamine salt -S0 ₂ copolymer, 9) dimethyldiallylammonium chloride polymer, 10) polymers of allylamine salts, 11) dialkylaminoethyl (meth) acrylate quaternary salt polymer, 1
2) Cationic compounds such as acrylamide-diallylamine salt copolymer. The cationic compound can be used in an amount of 1 to 100 parts by weight, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the pigment. If the compounding amount is small, it is difficult to obtain the effect of improving the printing density, and if it is too large, the printing density may be reduced or the image may be blurred.

In addition, various auxiliaries such as a dispersant, a thickener, an antifoaming agent, a coloring agent, an antistatic agent and a preservative used in the production of general coated paper are appropriately added. The coating layer composition composed of the above materials generally has a solid content of 5 to 5.
Adjusted to about 65% by weight, the basis weight is about 20-400g / m
^A blade coater, an air knife coater, a roll coater, a brush coater, a champlex coater, a bar coater so that the dry weight is about 1 to 50 g / m ² , more preferably about ² to ²⁰ g / m ^{2 on} about ² substrates. , A gravure coater, a die coater, a curtain coater, and other various known and publicly used coating devices. Further, if necessary, a smoothing treatment such as super calendering or brushing can be performed after the coating layer is dried.

Next, a gloss layer can be further provided on the coating layer containing the pigment and the adhesive as main components. This gloss layer is formed by containing a resin. The gloss layer is preferably made porous or liquid-permeable so as not to impair the gloss so that the ink can pass or absorb the ink quickly. In order to achieve this, it is preferable to mix a pigment or select a drying condition that does not completely form a resin film within a range that does not reduce gloss.

The pigments used for the glossy layer include the same pigments as those used for the undercoat layer. However, in terms of gloss, transparency and ink absorption, colloidal silica, amorphous silica, aluminum oxide, zeolite, Synthetic smectite and the like are preferred. It is desirable that these pigments are contained in the coating layer in an amount of 10 to 80% by weight. Since the larger the BET specific surface area of the pigment is, the more excellent the ink absorbency is, it is 150 m ² / g.
The above is preferred. Although there is no particular upper limit, for example, 1000 m
Pigments of the order of ² / g are available. The average particle size of the pigment is preferably from 0.01 to 5 μm, more preferably from 0.05 to 1 μm. If the particle diameter is less than 0.01 μm, the effect of improving the ink absorbency is poor, and if it exceeds 5 μm, the gloss and the print density may be reduced. In particular, as a pigment, the average particle size of the primary particles is 3 nm or more and 40 nm or less, and the average particle size of the secondary particles is 10 nm or more and 300 nm.
When the following silica fine particles are used, gloss and ink absorbability are particularly excellent. It is particularly preferable that the glossy layer is formed with a pigment as a main component (10 to 80%).
In this case, since the glossy layer is excellent in ink absorption and transparency, if a cationic compound is blended in the glossy layer, the ink dye is efficiently fixed to the glossy layer, and the print density is extremely excellent in combination with the transparency of the glossy layer. Easily.

Examples of the resin for the gloss layer include organic polymers, particularly polyvinyl alcohols, aqueous urethane resins, and polymer resins obtained by polymerizing monomers having an ethylenically unsaturated bond. The aqueous urethane resin is obtained by reacting an isocyanate such as diisocyanate, triisocyanate and tetraisocyanate with a polyol. Among them, a polymer composition obtained by polymerizing a monomer having an ethylenically unsaturated bond (hereinafter, referred to as an ethylenic monomer) is suitably used. Examples of such a polymer include methyl acrylate, ethyl acrylate, butyl acrylate, and the like. Acrylic acid ester having 1 to 18 alkyl groups such as 2-ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl Alkyl groups such as methacrylates having 1 to 18 carbon atoms, methacrylic acid esters, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride,
Examples include polymers obtained by polymerizing ethylenic monomers such as vinylidene chloride, vinyl acetate, vinyl propionate, acrylamide, N-methylolacrylamide, ethylene, butadiene, acrylic acid, and methacrylic acid.

The polymer may be a copolymer of two or more ethylenic monomers, if necessary, or a substituted derivative of these polymers or copolymers. Further, the above-mentioned ethylenic monomer is polymerized in the presence of colloidal silica, and Si—O—R (R:
(Polymer component) A functional group which reacts with colloidal silica such as a SiOH group is introduced into the polymer or copolymer in the form of a composite by bonding, or is reacted with colloidal silica to form a composite. It is also possible to use it in a different form. When this composite is used, it tends to be excellent in gloss and ink absorbency, and when it uses a casting method described later, it tends to be excellent in release from a cast drum. The composite particles are not particularly limited, but have, for example, an average particle size of about 30 to 150 nm.

The above (co) polymer preferably has a glass transition point of 40 ° C. or higher, more preferably 50 to 100 ° C. When the glass transition point is low, film formation proceeds excessively during drying, and as a result, the porosity of the surface decreases,
There is a possibility that the ink absorption speed is reduced. In addition, the drying temperature is important. If the drying temperature is too high, the film formation proceeds too much, and the porosity of the surface is reduced. As a result, the ink absorption rate decreases, and if the drying temperature is too low, the gloss is poor. And the productivity also decreases. The glossy layer may be obtained by applying a coating liquid composed mainly of a resin and, if necessary, a pigment on the coating layer and subjecting the coating liquid to a smoothing treatment using a super calendar or the like as appropriate.

However, preferably, a coating liquid composed mainly of a resin and, if necessary, a pigment is applied, and the coating layer is pressed against a heated mirror drum while the coating layer is in a wet state, and dried. To finish (wet cast method),
Alternatively, a method of once drying and re-wetting the coating layer, pressing it against a heated mirror-surface drum, and drying and finishing (rewet casting method) is preferable because an ink jet recording medium having both excellent gloss and ink absorbency can be obtained. . The temperature of the heated mirror drum is, for example, 50 to 150 ° C, preferably 70 to 120 ° C. Further, a coating liquid containing resin and, if necessary, a pigment was directly applied to the heated mirror-surface drum, and a recording layer was previously provided while the coating layer was wet to some extent. It is also possible to adopt a method of pressing and drying the base material to finish it (precast method). Further, a coating liquid containing a resin and, if necessary, a pigment is applied on a smooth film or sheet, and the coating layer or the recording layer surface to be bonded is in a somewhat wet state. In the meantime, a method (film transfer method) in which a smooth film or sheet is peeled off and finished after being pressed against and dried on the base material can also be adopted.

The coating composition for the gloss layer contains whiteness, viscosity,
In order to adjust the fluidity, etc., various aids such as pigments, antifoaming agents, coloring agents, antistatic agents, preservatives and dispersants, and thickeners used in general printing coated paper and inkjet paper are used. An agent can be appropriately added. It is also possible to mix a cationic resin to impart ink dye fixability to the glossy layer. When applying the coating liquid for the gloss layer described above on the recording layer, a blade coater, an air knife coater, a roll coater, a brush coater, a chaplex coater, a bar coater, a gravure coater, a die coater,
Various known coating apparatuses such as a curtain coater can be used. Thereafter, preferably, while the coating layer is in a wet state as described above, or after once drying and re-wetting, a cast finish is performed by pressing against a heated mirror-surface drum and drying. In this case, the coating amount of the gloss layer coating liquid is 0.2 to 30 g / m ² , preferably 1 to 10 g / m ^{2 as} a dry solid content.
² Here, if it is less than 0.2 g / m ² , the gloss may not be sufficiently obtained, and if it exceeds 30 g / m ² , the ink drying property may be poor or the recording density may be reduced.
After the gloss layer is provided, a smoothing process can be further performed by using a super calendar or the like. It is also possible to provide only one recording layer also serving as a gloss layer on the base material and finish it by the above-mentioned casting method to obtain a casting type inkjet recording material. In this case, the pigments described above for the gloss layer are preferably used.

Incidentally, in order to obtain an image having excellent photographic tone,
A recording medium having excellent glossiness is preferable, and the 75 ° glossiness (JIS Z 8741) of the surface to be recorded is preferably 30% or more, whereby excellent image quality and high-quality photographic tone recording can be obtained. The gloss is more preferably at least 40%, most preferably at least 65%. Although there is no particular upper limit, it is, for example, 95%.

Next, the coating layer of another gloss type ink jet recording material other than the cast method will be described. The ink jet paper of the type according to the present embodiment includes a recording layer having a base material and an ink-absorbing resin as main components, and the ink-absorbing resin used in the recording layer is a natural resin such as gelatin, casein, starch, and cationic starch, and polyvinyl. Synthetic resins such as alcohol, cationic polyvinyl alcohol, polyvinylpyrrolidone, polyurethane, polyester, sodium polyacrylate, carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose include, among others, polyvinylpyrrolidone, polyvinyl alcohol and hydroxypropylmethylcellulose. One of the cellulose derivatives of
The use of more than one species is preferred.

The recording layer may contain a plasticizer. A plasticizer is an additive that can be added to an ink-absorbing resin to improve its flexibility, and examples of such a plasticizer include phosphate esters such as tributyl phosphate,
Examples include phthalic acid esters such as dibutyl phthalate, fatty acid esters such as di-2-hexyl adipate, polyhydric alcohols such as polyethylene glycol and glycerin, and esters or ethers thereof. Preferred plasticizers to be contained in the ink-receiving layer of the present invention include polyethylene glycol, polypropylene glycol, polypropylene glycol, polyglycols such as polyoxytetramethylene glycol and glycerin, and the like. Is more preferred. If it is less than 200, the printed matter tends to spread over time, and
If it is more than 00, the receiving layer becomes cloudy and the glossiness may be poor. Further, a cationic resin can be blended in the recording layer for the purpose of imparting ink fixability. Examples of the cationic resin include the same resins as those described above in the recording layer of the general inkjet recording medium and the cast glossy inkjet recording medium.

When the cationic resin is blended, the blending amount is 1 to 30 parts by weight, preferably 1 to 10 parts by weight based on 100 parts by weight of the ink absorbing resin. If the amount is less than 1 part by weight, sufficient water resistance may not be obtained, and if the amount is more than 30 parts by weight, the ink drying property may be reduced. In addition to this, in the coating layer constituting the recording layer, a polyolefin resin, a urethane resin, an acrylic resin, a polyester resin, for the purpose of improving the water resistance of the recording layer coating film, as long as the effects of the invention are not impaired. A resin emulsion such as a vinyl acetate resin or various latexes may be blended.

Various inorganic and organic pigments and particles can be added for the purpose of adjusting the gloss and transparency of the recording sheet and preventing blocking. Examples of inorganic pigments include silica, clay, talc, calcium carbonate, aluminum silicate, zeolite, and alumina.Examples of organic pigments and particles include various plastic particles such as styrene resin, acrylic resin, and urethane resin, and cellulose fine particles. Powders and starch particles are mentioned. Further, in the recording layer, various auxiliary agents such as a dispersant, a cross-linking agent, a thickener, a defoamer, a wetting agent, a fluorescent dye, a colorant, an antistatic agent, a preservative, and an ultraviolet absorber are used as needed. It is added as appropriate. The recording layer of the present invention can be applied directly on the substrate, but for the purpose of improving the adhesion to the substrate, or subjected to a surface activation treatment such as a corona discharge treatment or a flame treatment, or An undercoat layer may be provided.

The coating composition for a recording layer composed of the above-mentioned materials can be coated on a substrate by, for example, a bar coater, a blade coater, an air knife coater, a roll coater, a gravure coater, a curtain coater by various known coating methods. It is coated and dried by various known and publicly used coating devices such as a die coater. The coating amount of the recording layer is not limited as long as desired printability (for example, ink absorbency, ink dryness, color developability, bleeding, print density, sharpness, etc.) can be obtained. ５０50 g / m ² , more preferably 5-30 g / m ² . If the amount is less than 2 g / m ² , the ink absorption tends to be insufficient, and the ink tends to bleed or dry. If the amount exceeds 50 g / m ² , the effect is saturated and the cost is disadvantageous. Inconveniences such as difficulty in controlling curl occur.

[0037]

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 thereto.
Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified. (Substrates 1 to 5) Various substrates having the qualities shown in Table 1 below are used. The recording layer was provided on the surface described as “table” in the item of smoothness in the following table.

[0038]

[Table 1]

(Formulation 1) Amorphous silica (specific surface area 240
280 m ² / g, average particle size 3 μm, primary particle size 10 n
m, trade name: Fine Seal X-37 (made by Tokuyama)) 100 parts, polyvinyl alcohol (trade name: R-1130 (made by Kuraray)) 20 parts,
10 parts of a polydiallyldimethylammonium chloride-based cation resin (trade name: PAS-H-5L (manufactured by Nitto Boseki)). (Prescription 2) Polyvinyl alcohol (trade name: PVA42)
0 (manufactured by Kuraray)), 5 parts of an acrylamide diallylamine copolymer cationic resin (trade name: SR1001 (manufactured by Sumitomo Chemical)), amorphous silica (specific surface area: 325 m ² /
g, trade name: P-78D (Mizusawa Chemical Co., Ltd.)) 0.5 part.

(Formulation 3) Amorphous silica (specific surface area 240
280 m ² / g, average particle size 3 μm, primary particle size 10 n
m, trade name: Fine Seal X-37 (manufactured by Tokuyama)) 60 parts, zeolite (average particle diameter 1.5 μm, trade name: Toyo Builder (manufactured by Tosoh Corporation)) 40 parts, silyl-modified polyvinyl alcohol (trade name) : R-1130 (manufactured by Kuraray)) 15 parts, dicyandiamide-based cation resin (trade name: Neofix E-117 (manufactured by Nika Chemical Co., Ltd.)) 10 parts, and sodium polyphosphate (dispersant) 0.5 part. (Prescription 4) Composite of styrene-2-methylhexyl acrylate copolymer and colloidal silica (trade name: Movinyl 8055 (Hoechst Synthesis Co., Ltd.), Tg = 75 ° C., copolymer: colloidal silica = 50: 50, colloidal Silica is a dispersion of 30 nm primary particles and the composite particle size is 80
nm) 100 parts, 5 parts of alkyl vinyl ether / maleic acid derivative copolymer (thickening and dispersing agent), 3 parts of lecithin (release agent).

(Formulation 5) Amorphous silica (specific surface area 290)
m ² / g, average particle diameter 6 μm, primary particle diameter 15 nm, trade name: Fine Seal X-60 (manufactured by Tokuyama)) 80 parts, zeolite (average particle diameter 1.5 μm, trade name: Toyo Builder (Tosoh)
20 parts, silyl-modified polyvinyl alcohol
(Trade name: R-1130) 20 parts, a composite of styrene-2-methylhexyl acrylate copolymer and colloidal silica (trade name: Movinyl 8055 (Hoechst synthesis (
Co., Ltd.), Tg = 75 ° C., copolymer: colloidal silica = 5
0:50) 50 parts, fluorescent dye (trade name: WHITEX BPS)
H; manufactured by Sumitomo Chemical) 2 parts.

(Formulation 6) The following silica fine particles 100
Parts, diallyldimethylammonium chloride-acrylamide copolymer (trade name: PAS-J-81 (manufactured by Nitto Boseki)), 10 parts, cationic aqueous urethane resin (trade name: F-8564D, Tg = 73 ° C (Daiichi Kogyo) Pharmaceuticals (
Co., Ltd.), 30 parts, cationic polyethylene WAX (trade name: Pertol N-856 (Hyundai Kagaku Kogyo Co., Ltd.)) 25
Department. Preparation of silica fine particles [Silica fine particles] Synthetic amorphous silica (manufactured by Tokuyama Corporation,
Product name: Fine Seal X-45, BET specific surface area: 2
90 m ² / g) aqueous homogenizer (trade name: Ultra High Pressure Homogenizer GM, manufactured by SMT Co., Ltd.)
-1), and the pulverization operation was repeated (pressurized to 500 k).
g / cm ² ). The solid concentration after the treatment was 12%.
The primary particle size after the treatment was 15 nm, and the secondary particle size was 50 nm.

Example 1 A coating liquid (18%) of Formulation 1 was applied to one surface of a substrate 1 with an air knife coater to a dry weight of 8 g / m ² and dried to obtain an ink jet paper. Example 2 In Example 1, except that the substrate was changed from 1 to 2,
In the same manner as in Example 1, an inkjet paper was obtained.

Example 3 In Example 1, except that the substrate was changed from 1 to 3,
In the same manner as in Example 1, an inkjet paper was obtained. Example 4 A coating liquid (15%) of Formulation 2 was applied to one surface of the substrate 2 with a bar coater so as to have a dry weight of 8 g / m ² and dried to obtain a glossy inkjet paper.

Example 5 A coating liquid (18%) of Formulation 3 was applied to one surface of the substrate 1 with an air knife coater so as to have a dry weight of 7 g / m ² and dried to obtain an undercoat recording layer. . On the undercoat recording layer, a coating liquid (28%) for the glossy layer of Formulation 4 was applied using a roll coater, immediately pressed against a mirror drum having a surface temperature of 85 ° C., dried, and released. Then, a cast type glossy inkjet paper was obtained. Example 6 A cast type glossy inkjet paper was obtained in the same manner as in Example 5, except that the substrate was changed from 1 to 2.

Example 7 A coating liquid (20%) of Formulation 5 was applied to one surface of the substrate 1 (one of the substrates 1 to 5 was applied in the direction corresponding to the smoothness table) at a dry weight of 14 g / m ² . It was coated with an air knife coater and dried to obtain an undercoat layer. Next, on the undercoat layer, a glossy coating solution (12%) of Formula 6 was applied using an air knife coater to a dry weight of 6 g / m ^2, and dried with cold air for 25 seconds to obtain a semi-dry state. After that (moisture percentage of 150% based on the absolute drying amount of the coating layer), it was pressed against a mirror drum having a surface temperature of 100 ° C., dried, and released to obtain a cast type glossy inkjet paper.

Example 8 Example 7 was repeated except that the substrate in Example 7 was changed from 1 to 2.
In the same manner as in the above, a cast type glossy inkjet paper was obtained. Comparative Example 1 An ink jet paper was obtained in the same manner as in Example 1 except that the number of substrates was changed from 1 to 4. Comparative Example 2 An ink jet paper was obtained in the same manner as in Example 1 except that the substrate in Example 1 was changed from 1 to 5.

Comparative Example 3 An ink jet paper was obtained in the same manner as in Example 4 except that the substrate in Example 4 was changed from 2 to 4. Comparative Example 4 An ink jet paper was obtained in the same manner as in Example 4 except that the substrate in Example 4 was changed from 2 to 5. Comparative Example 5 An ink jet paper was obtained in the same manner as in Example 4, except that the substrate in Example 7 was changed from 1 to 4.

Comparative Example 6 An ink jet paper was obtained in the same manner as in Example 4 except that the substrate in Example 7 was changed from 1 to 5. Comparative Example 7 Substrate 1 was used as it was (printed on the front surface of the substrate).

Table 2 summarizes the operability, ink jet recording suitability, glossiness of white paper, and occurrence of cockling after printing of the ink jet recording paper thus obtained. In addition, about the said evaluation, evaluation was performed by the following methods. [Inkjet recording suitability] Printing was performed using an inkjet printer BJC420J (using ink cartridges BCI-21BLACK and BCI-21COLOR manufactured by Canon Inc.). (Print bleeding) Solid printing portions of black, cyan, magenta, and yellow inks were printed so that their borders were in contact with each other, and bleeding at the borders was visually evaluated. A: Good level without bleeding. ：: Slight bleeding, but not practically problematic. Δ: Bleeding is somewhat noticeable, and is a level that is somewhat problematic in practical use. X: A level at which bleeding is remarkable and becomes a serious problem in practical use.

(Dryability of Ink) The dryness of the ink was evaluated for a solid printing portion of a mixture of two colors of a cyan ink and a magenta ink. ：: No stain at all even if touched with a finger immediately after printing. ○-: Slightly stained when touched with a finger immediately after printing, but at a level with no practical problem. ×: Stained when touched with a finger immediately after printing. (Status of cockling occurring after printing) The status immediately after printing was visually evaluated. ：: No cockling was observed and good. ×: This is a level at which cockling occurs and poses a problem. [Print Density] Macbeth RD
Measured at -914. [Gloss] 75 ° of blank paper according to JIS-P8142
The gloss was measured. [Comprehensive evaluation] Comprehensive evaluation of printing quality and press-contact quality. 4: Excellent. 3: Normal. 2: Slightly inferior. 1: Poor.

[0052]

[Table 2]

[0053]

According to the present invention, there is no blur, excellent ink jet recording suitability such as print density, excellent ink absorption, and excellent print surface smoothness and dimensional stability after printing.
It is an ink jet recording medium in which cockling does not occur. Further, the present invention provides an inkjet recording cast paper having excellent printing quality and excellent gloss.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 2C056 FC06 2H086 BA13 BA15 BA19 BA41 BA42 4F100 AK01A AK03A AR00B BA02 DJ00A GB90 JD02A JD15A JD20A JK15 JL04 JN21B YY00A

Claims (5)

[Claims] 1. An ink jet recording medium comprising at least one recording layer provided on a base material, wherein the base material is a microporous synthetic resin film sheet and the water absorption of Cobb (JIS P
8140) is 10 g / m ² or more. 2. The degree of Sechigt sizing of the substrate (JIS P
8122) is 500 seconds or less. 3. The ink jet recording material according to claim 1, wherein the synthetic resin constituting the microporous synthetic resin film sheet is a polyolefin resin. 4. A recording layer or a gloss layer provided with a gloss layer on the recording layer, which is finished by pressing against a heated mirror drum and drying. Inkjet recording medium. 5. The air permeation amount of a substrate (JIS P8117)
Is less than or equal to 2500 seconds.
5. The ink jet recording material according to 2, 3 or 4.