JP2002046347A - Recording sheet and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet, which is highly glossy and excellent in ink absorbency and, at the same time, is excellent in color developing density, water resistance, light resistance and resistance to yellowing, and its manufacturing method. SOLUTION: This ink jet recording sheet has at least one or more layers including cationic organic particles on a sheet-like support under the condition that the layer including the cationic organic particles has a void forming component consisting substantially of a specified (co)polymer and, at the same time, cationic organic particles selected from material, to which a cationic function is given.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a printer or a plotter utilizing an ink jet recording system, and particularly, an ink jet recording sheet having gloss comparable to that of a commercially available cast paper and a method for producing the recording sheet. It is about.

[0002]

2. Description of the Related Art In an ink jet recording system, fine droplets of ink are caused to fly according to various operating principles and adhere to a recording sheet such as paper to record images and characters. The recording method has features such as high speed, low noise, easy multi-coloring, great flexibility in recording patterns, and no need for development and fixing. It is rapidly spreading in applications.
Further, the image formed by the multi-color inkjet method is
By expanding the resolution and color reproduction range, it is possible to obtain recordings that are comparable to multi-color printing by the plate making method and printing by the color photographic method. Due to its low cost, it is being widely applied to the field of full-color image recording.

Further, printers and plotters using the ink jet system have been required to have higher resolution and an expanded color reproduction range in response to demands for further improvement in image quality from the market. This is addressed by increasing the discharge amount. Therefore, an increase in the ink receiving capacity corresponding to the ejection amount is an important technical problem of the recording sheet, and it is essential to secure a high ink receiving capacity and to apply a coating layer having good coloring properties. In addition, gloss, rigidity,
It is demanded that the appearance such as hue is similar to silver halide photographs and printing paper, and it has become impossible for conventional ink jet recording sheets of high quality paper and coated paper to meet these demands.

[0004] In particular, in the prior art, when gloss is imparted,
A problem arises in that the ink absorbency, which is an important property required for an ink jet recording sheet, is lacking. To ensure the absorption, it is necessary to provide a coating layer having a large amount of voids, and a large amount of inorganic particles have been applied to the coating composition of the coating layer, but the coating layer surface is affected by the particles. Because of the rough surface, only a so-called matte tone having low gloss was obtained.

By the way, as a processing method for imparting gloss, a method of using a calender such as a super calender or a gloss calender and smoothing the surface of a coating layer by passing paper between rolls under pressure or temperature is generally used. It is a target. However, when calendering is performed under a high linear pressure for the purpose of imparting gloss to the ink jet recording sheet, the gloss improves, but the voids in the coating layer decrease, the ink absorption becomes slow, and the absorption capacity becomes insufficient. There is a problem that ink overflows from the ink. For this reason, in the calendar process, the conditions must be selected within the range of the allowable ink absorption capacity, and at present, it is difficult to obtain ink absorption and gloss with the current technology.

Further, in order to achieve both ink absorption and gloss, which are contradictory characteristics, a coating layer contains a large amount of fine inorganic particles, and an ink jet recording sheet is manufactured by a method called a cast coating method. However, even with these methods, it is difficult for ink jet printers and plotters with a large amount of ink discharged in recent years to achieve both ink absorption and gloss, which are contradictory characteristics. When the ink absorptivity is improved by improving the ink absorptivity by designing the ink absorptivity, for example, using a large amount of inorganic particles to increase the voids, there is a problem that the surface strength is reduced. . In addition, when a design with an emphasis on gloss, for example, when the amount of inorganic particles used is reduced, high gloss can be obtained, but there is a problem that voids are reduced and it is difficult to ensure ink absorbency.

[0007] In general, the ink liquid used in the ink jet recording method has an anionic water-soluble dye dissolved in a solvent containing water as a main component. When ink absorption is improved by using a large amount of inorganic particles to increase voids, there is a problem that the dye penetrates deeply into the recording sheet and the color density decreases. In order to improve the color density,
It is necessary to fix the dye in the ink to the surface layer of the recording sheet as much as possible. Further, in order to improve the water resistance, that is, to prevent the dye from being detached when the recording sheet comes into contact with water, it is necessary to fix the dye to the surface layer of the recording sheet. In order to solve this problem, a method of containing a cationic polymer in the coating layer and fixing an anionic dye has been proposed, but when the amount of the cationic polymer is increased,
Since the content of the inorganic particles is reduced, there is a problem that it is difficult to secure the ink absorbency.

Further, in recent years, with the technical progress of the ink jet recording system, it has become possible to obtain a clear image and excellent print quality, and it is possible to obtain an image quality comparable to a photograph. However, compared to photographs, there are problems with light fastness, that is, fading of printed images when stored for a long time, and yellowing resistance, that is, yellowing of the recording sheet surface when stored for a long time. However, a recording sheet having high gloss, as described above, currently contains a large amount of fine inorganic particles in the coating layer, and achieves both high gloss and ink absorbency. Finer inorganic particles are being selected. Generally, silica and alumina are preferably used as the inorganic particles, but the finer the particle size, the larger the surface area dramatically increases, and the higher the surface activity of the inorganic particles, the lower the light resistance and yellowing resistance. There is a problem.

From the above, it is presently difficult to obtain an ink jet recording sheet that satisfies all of high gloss, ink absorption, color density, water resistance, light resistance, and yellowing resistance with the current technology. . Here, examples of the current technology are as follows.

For example, JP-A-11-11011 discloses that
An ink jet recording sheet is disclosed in which a coating composition comprising cationic colloid particles containing alumina as a main component and a cationic latex is cast-coated at a temperature higher than the glass transition temperature of the latex.
The amount of the cationic colloid particles containing alumina as a main component and the latex is preferably 2 to 70 parts by mass, most preferably 3 to 30 parts by mass, per 100 parts by mass of the cationic colloid particles. In addition, although the detailed definition of the cationic latex is not clear, it is a cationized using a cationic group, a cationized latex surface with a cationic surfactant, and in Examples, the cationic surfactant is used. Are evaluated.

[0011] Also, JP-A-11-123867 discloses that
An ink jet recording sheet in which a white pigment layer contains a cationic acrylic resin emulsion is disclosed. The white pigment is inorganic particles such as clay, calcium carbonate, and titanium oxide, or organic particles such as polyethylene, polystyrene, and polyacrylate. The ratio of the cationic acrylic resin emulsion mixed in the white pigment layer is 100 mass of the white pigment. 100 to 100 parts by dry mass solids
5 parts by weight, most preferably 50 to 30 parts by weight. The amount of the cationic monomer used for obtaining the cationic acrylic resin emulsion is preferably 1 to 5% by mass based on all the monomers.

JP-A-11-58943 discloses an ink jet recording material obtained by applying a coating solution containing non-spherical silica and a water-dispersible cationic polymer on a support and drying the coating solution. ing. The content of the water-dispersible cationic polymer in the ink receiving layer is 1 to 30% by mass.
Preferably, the content of the inorganic particles is 75 to 95% by mass.

JP-A-11-20306 discloses an ink jet recording sheet having an ink absorbing layer containing a cationic mordant having a mordant power on anionic dyes on a support. The ink absorbing layer contains inorganic fine particles of silica or alumina, and the amount of the cationic mordant is 0.01 to 0.3 in mass ratio with respect to the inorganic particles, and the cationic mordant has an average molecular weight of 50,000 or less. It is preferable that it is an acidic mordant.

Japanese Patent Publication No. 7-53469 discloses an ink jet recording sheet having a coating layer comprising a pigment and a binder resin on a support, wherein the binder comprises (a) a component containing a fatty acid vinyl ester; b) 0.05-
There is disclosed an ink jet recording sheet which is a cationic copolymer comprising a cationic monomer having 0.4 mol% of an ethylenically unsaturated group and a tertiary amino group or a quaternary ammonium group. The pigment is fine-particle silica or the like, and the content of the cationic copolymer in the coating layer is 5%.
It is preferable that the content be 50 to 50% by mass.

JP-A-9-59898 discloses that a paper substrate is composed of 80 to 98.5 mol% of ethylene structural units, 0.5 to 10 mol% of acrylate structural units and 1 to 10 mol% of cationic acrylamide structural units, A resin-coated paper for printing provided with a coating layer containing a copolymer emulsion having a weight average molecular weight of 1,000 to 50,000 is disclosed. This resin coated paper for printing has good suitability for offset printing. These documents use inorganic fine particles to express voids, and various polymers used in these are used as a binder resin for binding the inorganic fine particles. Have drawbacks due to using.

[0016]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems by providing high gloss and excellent ink absorbability.
Another object of the present invention is to provide an ink jet recording sheet excellent in color density, water resistance, light resistance, and yellowing resistance, and to provide a method for producing the recording sheet.

[0017]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found that at least one or more layers containing specific cationic organic particles are provided on a sheet-like support. It has been found that an ink jet recording sheet provided with a specific amount of liquid absorption and gloss has high gloss, excellent ink absorption, and excellent color density, light fastness, and yellowing resistance. Was completed.

[1] An ink jet recording sheet having at least one layer containing cationic organic particles on a sheet-like support, wherein the layer containing cationic organic particles contains a void-forming component. Wherein the component is substantially one or more selected from (meth) acrylate (co) polymers, methyl methacrylate-butadiene copolymers, styrene-butadiene copolymers, ethylene-vinyl acetate copolymers or olefin-based polymers, or An ink jet recording sheet comprising two or more (co) polymers and cationic organic particles selected from materials having a cationic function. [2] The ink jet recording sheet according to [1], wherein the cationic organic particles are thermoplastic resin particles. [3] The cationic organic particles copolymerize (A) an alkyl (meth) acrylate, (B) an amino group-containing (meth) acrylate monomer, and (C) another copolymerizable monomer. The recording sheet for inkjet according to any one of [1] to [2], which is a cationic emulsion particle obtained by the above. [4] Based on the total mass of the (A) alkyl (meth) acrylate monomer, the (B) amino group-containing (meth) acrylate monomer, and (C) other copolymerizable monomers. , (A) is 30% by mass or more.
99.8% by mass, (B) is 0.2% by mass to 40% by mass,
4. The ink jet recording sheet according to claim 3, wherein (C) is 0% by mass to 30% by mass. [5] The cationic organic particles have a glass transition temperature of 6
[1]-characterized by being at least 5 ° C and not more than 200 ° C
The recording sheet for inkjet according to any one of [3]. [6] The weight average molecular weight of the cationic organic particles is 6
The inkjet recording sheet according to any one of [1] to [5], wherein the recording sheet has an average molecular weight of 0000 or more. [7] 4 μl of pure water was dropped on the recording surface of the recording sheet, and the liquid absorption amount after 0.1 second from the dropping was 2.00 to 4.0.
The inkjet recording sheet according to any one of [1] to [6], wherein the recording sheet has a volume of 0 μl and a gloss at 75 ° of 50 or more. [8] 4 μl of pure water was dropped on the recording surface of the recording sheet, and the liquid absorption amount per contact area of the droplet on the recording surface 0.1 second after dropping was 0.5 to 2.00 μl. / Cm ²
The recording sheet for inkjet according to any one of [1] to [7], wherein: [9] The ink jet recording sheet according to any one of [1] to [8], wherein the layer containing the cationic organic particles is an outermost layer on a recording surface. [10] The ink jet recording sheet according to any one of [1] to [9], wherein the sheet-like support is a paper or a plastic sheet. [11] The ink jet recording sheet according to any one of [1] to [10], wherein the layer containing the cationic organic particles does not contain inorganic particles. [12] A method for producing an ink jet recording sheet in which a layer containing cationic organic particles is applied by a cast coating method, wherein a coating composition containing cationic organic particles is applied on a sheet-like support. The method for producing an ink jet recording sheet according to any one of [1] to [11], wherein a mirror roll is then pressed against the coating surface of the coating composition. [13] The method for producing an ink jet recording sheet according to [12], wherein the surface temperature of the mirror roll is lower than the glass transition temperature of the cationic organic particles.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The ink jet recording sheet of the present invention is a recording sheet having at least one layer containing cationic organic particles on a sheet-like support, wherein the recording sheet has a specific absorption property. An ink jet recording sheet having a liquid amount and gloss. Less than,
This will be described in detail.

[Method of Measuring Liquid Absorbing Amount] The liquid absorbing amount on the recording surface in the present invention is defined as a water droplet of 4 μl of pure water on the recording surface of a sample held horizontally at 20 ° C. and 65% RH. The liquid was deposited vertically, and the amount of liquid absorbed 0.1 second after the deposition was measured. It is necessary to absorb a large amount of ink in a very short time after ink deposition on the recording sheet. This is because if the ink is gradually absorbed after landing, bleeding occurs and the image quality deteriorates.

The above-mentioned liquid absorption is specifically determined as follows. The measurement can be performed using a DAT (Dynamic Absorption Characteristics Tester) 1100 DAT MKII machine manufactured by FIBRO. First, 4 μl of pure water is dropped on the sample surface,
Video recording of the condition after dropping. Then, the amount of liquid remaining on the sample surface is calculated from the contact angle and diameter of the droplet that has arrived 0.1 seconds after the video image, and the amount of liquid absorbed is calculated from the difference between this amount and the amount of the dropped droplet. It is a system called. The unit of the liquid absorption calculated here is volume (μl). Furthermore, if this value is divided by the contact area calculated from the diameter of the deposited droplet, the liquid absorption amount per unit area (μl
/ Cm ² ) can be calculated. The specific calculation formula is as follows. Liquid absorption per unit area (μl / cm ² ) = liquid absorption (μ
l) / [(droplet diameter (cm) / 2) ² × π] Here, the meaning of expressing the liquid absorption amount in two types of units is as follows. For example, when the amount of liquid absorption expressed in volume units (μl) is large, drying is quick because of excellent ink absorption, but when the amount of liquid absorption per unit area (μl / cm ² ) is low, Because the spread of the droplets on the recording sheet surface is large, bleeding is likely to occur,
Image quality may be degraded. Therefore, those having a high liquid absorption amount (μl / cm ² ) per unit area are more preferable.

The recording sheet of the present invention has a water absorption of 2.00 when a water droplet of 4 μl of pure water is vertically deposited on the surface of the recording surface and the liquid absorption 0.1 second after the landing is measured. ~ 4.0
0 μl is preferable, and more preferably 3.00 μl
４4.00 μl. When the liquid absorption amount is 2.00 μl or more, the ink absorption is good and the drying property is also good. Since the amount of pure water to be dropped is 4 μl, the amount of liquid absorbed is 4.00 μl.
Cannot be exceeded.

Further, the amount of liquid absorption in the recording sheet of the present invention is defined as the amount of liquid absorption per unit area (μl / cm ² ).
But it is preferably 0.50~2.00μl / cm ^2, more preferably 0.50~1.50μl / cm ²
It is. When the amount of liquid absorption is 0.50 μl / cm ² or more, the ink absorbency is good, and the image does not deteriorate due to overflow of the ink. Further, when the liquid absorption amount is 2.00 μl / cm ² or less, the water resistance and the coloring density are preferably high.

[Measuring method of gloss] Gloss in the present invention is defined as 7 based on JIS Z8741.
The gloss was measured at 5 °. For example, it can be measured with a gonio-gloss meter GM-3D type (manufactured by Murakami Color Research Laboratory). As the recording sheet of the present invention, 75
The gloss in ° is 50 or more, preferably 60 or more, more preferably 65 or more, and most preferably 70 or more.
If it is less than 50, the gloss tends to be insufficient, and it may be difficult to say that the recording sheet has a gloss.

[Cationic Organic Particles] A preferred embodiment of the cationic organic particles in the present invention is a water-insoluble thermoplastic polymer particle having a cationic functional group such as an amino group. (Polymer or copolymer of acrylate and / or methacrylate), MBR polymer (methyl methacrylate-butadiene copolymer), SBR polymer (styrene-butadiene copolymer), EVA polymer (ethylene- (Vinyl acetate copolymer) or an olefin-based polymer. Further, an acrylic polymer is a more preferred embodiment because of its excellent long-term yellowing resistance of a recording sheet.

Further preferred embodiments of the cationic organic particles include (A) an alkyl (meth) acrylate monomer, (B) an acrylate monomer containing an amino group and / or a methacrylate monomer containing an amino group,
Further, it is a cationic organic particle obtained by copolymerizing (C) another copolymerizable monomer.

Hereinafter, each thermoplastic polymer will be described more specifically. (A) Specific examples of the (meth) acrylic acid alkyl ester-based monomer include, for example,
Acrylic esters; methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl Methacrylates such as acrylate, cyclohexyl acrylate, phenyl acrylate, and benzyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl Methacrylate Octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, and other (meth) alkyl acrylates having 1 to 12 carbon atoms, and one or more of these. Can be selected. As (A), those containing no benzene ring are preferred, and more preferred are methyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and ethyl methacrylate. , 2-ethylhexyl methacrylate. A monomer having a benzene ring may cause a problem in yellowing resistance.

Specific examples of (B) an amino group-containing (meth) acrylate monomer include N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylate, N, N-dimethylaminopropyl methacrylate, N, Nt-butylaminoethyl acrylate, N, Nt-butylaminoethyl methacrylate, N, N-monomethylaminoethyl acrylate,
Aminoalkyl acrylates or aminoalkyl methacrylates such as N, N-monomethylaminoethyl methacrylate; N, N-dimethylacrylamide, N, N-
Dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N, N-
N-aminoalkylacrylamide such as dimethylaminopropylacrylamide, N, N-dimethylaminopropylmethacrylamide, N, N-dimethylaminoethylacrylamide, N, N-dimethylaminoethylmethacrylamide, N-isopropylacrylamide or N-aminoalkylacrylamide
Aminoalkyl methacrylamides; the above amino (meth) alkyl acrylates quaternary salted with a halogenated methyl group, a halogenated ethyl group, a halogenated benzyl group or the like, such as chlorine, bromine or iodine as a halogen, and N
Quaternary salts of -aminoalkylacrylamide or N-aminoalkylacrylamides; acryloylmorpholine, 2- (2'-hydroxy-5'-methacryloyloxyethylphenyl) -2H-benzotriazole,
-(2'-hydroxy-5'-methacryloyloxyphenyl) -benzotriazole, 2-hydroxy-4-
(2-methacryloyloxy) ethoxybenzophenone, 2- (2′-hydroxy-5′-methacryloyloxyphenyl) -5-chlorobenzotriazole, 1,
Examples thereof include 2,2,6,6-pentamethyl-4-piperidyl methacrylate and 2,2,6,6-tetramethyl-4-piperidyl methacrylate, and one or more of these can be selected. . Among the above, preferred are the amino (meth) alkyl acrylates quaternary salified with a halogenated methyl group, a halogenated ethyl group, a halogenated benzyl group or the like which is chlorine, bromine, iodine or the like as a halogen; N-aminoalkylacrylamide or quaternary salts of N-aminoalkylacrylamides. Those containing a group other than an amino group and those giving cationicity to the polymer can be used in the present invention. These monomers include, in addition to the (meth) acrylate (co) polymer, methyl methacrylate-butadiene copolymer, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer or copolymers used to impart cationicity to olefin-based polymers. It can also be used as a polymer component. Moreover,
The use of amidinos as radical initiators can impart cationicity to polymers without the use of special copolymerization components, and the (co) polymer obtained therefrom can be used as cationic organic particles in the present invention. Can be.

As specific examples of (C) other copolymerizable monomers, any radically polymerizable monomer other than (A) or (B) can be used. For example, acrylic acid, methacrylic acid, itaconic acid, Unsaturated carboxylic acids such as maleic acid, fumaric acid, acrylic acid anhydride, methacrylic anhydride, maleic anhydride, itaconic anhydride, fumaric anhydride; 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2- Hydroxyl-containing vinyls such as hydroxyethyl methacrylate, hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate; styrene, 2-methylstyrene, t-butylstyrene, chlorostyrene,
Aromatic vinyls such as vinylanisole, vinylnaphthalene and divinylbenzene; amides such as acrylamide, methacrylamide, N-methylolmethacrylamide, N-methylolacrylamide, diacetoneacrylamide and maleic amide; vinyl acetate and vinyl propionate Vinyl esters such as vinylidene chloride and vinylidene fluoride; vinyl chloride;
Vinyl ether, vinyl ketone, vinylamide, chloroprene, ethylene, propylene, isoprene, butadiene, chloroprene, vinylpyrrolidone, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate,
Glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, acrylonitrile, methacrylonitrile, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,3 -Butylene glycol dimethacrylate,
1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropanetri Methacrylate, trimethylolpropane triacrylate, tetramethylolmethane triacrylate,
Tetramethylolmethanetetraacrylate, allyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, isopropenyl-α, α-dimethylbenzyl isocyanate, allyl mercaptan, etc., and one or more of these. Can be selected.

Here, as (C), a monomer having a functional group having a strong interaction with the dye, for example, a functional group having a hydrogen bonding ability is preferable because of its excellent light fastness. And hydroxyl group-containing vinyls, aromatic vinyls, amides and the like. Further, as those having excellent yellowing resistance, unsaturated carboxylic acids and hydroxyl group-containing vinyls are more preferable.

Further, (A) an alkyl acrylate monomer and / or an alkyl methacrylate monomer, (B) an acrylate monomer containing an amino group and / or a methacrylate monomer containing an amino group, and (C) other copolymers As for the composition ratio of the polymerizable monomer, (A) is 30% by mass to 9% based on the total mass.
9.8% by mass, (B) is 0.2% by mass to 40% by mass,
(C) is preferably 0% by mass to 30% by mass,
More preferably, (A) is 50% by mass to 99.8% by mass,
(B) is 0.2% by mass to 20% by mass, (C) is 0% by mass.
３０30% by mass.

When (A) is 30% by mass or more, the hydrophilicity of the cationic organic particles is appropriate, and the water resistance and ink absorption are good. When (A) is 99.8% by mass or less, the ink dye It can be immobilized and has good color density. Also,
When (B) is 0.2% by mass or more, it is easy to fix the ink dye, the coloring density and water resistance are appropriate, and (B) is 4%.
When the content is 0% by mass or less, the cationic organic particles have appropriate hydrophilicity, maintain water resistance, and have a suitable fine pore, so that the ink absorption is good.

[Molecular Weight of Cationic Organic Particles] The weight average molecular weight of the cationic organic particles of the present invention is 600.
It is preferably at least 00, more preferably at least 100,000. When the weight average molecular weight is 60,000 or more, the cationic organic particles hardly deform, and the voids do not decrease, so that the ink absorbency can be increased. The upper limit of the molecular weight is not particularly required, but need not be about 1,000,000 or more.

[Particle Diameter of Cationic Organic Particles] The average particle diameter of the cationic organic particles of the present invention is 0.01 μm.
m to 1 μm, more preferably 0.05 μm to
0.5 μm. When the average particle diameter is 0.01 μm or more, a suitable gap is formed between the particles and the ink absorbability is good. When the average particle diameter is 1 μm or less, the smoothness of the surface is good and the gloss is high, which is preferable.

[Glass Transition Temperature (Tg) of Cationic Organic Particles] The glass transition temperature of the cationic organic particles of the present invention is preferably 65 ° C. or higher, more preferably 7 ° C. or more.
5 ° C. or higher. The upper limit of the glass transition temperature is usually 200
° C, preferably 150 ° C. Glass transition temperature 65
If the temperature is lower than 0 ° C., fine voids in the surface layer are easily reduced, and the ink absorbency may be reduced. Also, when drying the coating layer, since the drying temperature is high and the fine voids are reduced,
The drying temperature must be lowered, which may reduce production efficiency. Incidentally, the glass transition temperature in the present specification,
It can be determined from a DSC curve based on JIS K7121.

[Production Method of Cationic Organic Particles] The cationic organic particles used in the present invention can be produced by a conventionally known emulsion polymerization method or mechanical emulsification method. For example, in the emulsion polymerization method, in the presence of a dispersant and an initiator, a method of collectively charging and polymerizing various monomers,
There is a method of performing polymerization while continuously supplying a monomer.
The polymerization temperature is usually 30 to 90 ° C.
A substantially aqueous dispersion of organic particles is obtained.

The dispersant preferably used herein includes a cationic surfactant and / or a nonionic surfactant. The details will be described below. Specific examples of the cationic surfactant include, for example, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, alkyl benzyl dimethyl ammonium chloride, lauryl betaine, stearyl betaine, lauryl dimethyl amine oxide , Lauryl carboxymethyl hydroxyethyl imidazolinium betaine, coconutamine acetate, stearylamine acetate, alkylaming anidine polyoxyethanol, alkylpicolinium chloride, and the like.
Species, or two or more species can be selected.

Specific examples of the nonionic surfactant include:
For example, polyoxyethylene lauryl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl phenyl ether, polyoxyethylene nonyl phenyl ether, oxyethylene / oxypropylene block copolymer, tert-octylphenoxyethyl polyethoxyethanol, nonylphenoxyethyl poly Ethoxyethanol and the like can be mentioned, and one or more of these can be selected.

Further, a cationic water-soluble polymer and / or a nonionic water-soluble polymer can be used as a dispersant. Examples of the cationic water-soluble polymer include cationized polyvinyl alcohol, cationized starch, cationized polyacrylamide, cationized polymethacrylamide, polyamide polyurea, polyethyleneimine, a copolymer of allylamine or a salt thereof, and epichlorohydrin-dialkylamine addition polymer. , A polymer of diallylalkylamine or a salt thereof, a polymer of a diallyldialkylammonium salt, a diallylamine or a salt thereof and a sulfur dioxide copolymer, a dilyldialkylammonium salt-sulfur dioxide copolymer, a diallyldialkylammonium salt and a diallylamine or the same Copolymer with salt or derivative, dialkylaminoethyl (meth) acrylate quaternary salt polymer, diallyldialkylammonium salt-acrylamide copolymer, amine-ca Include Bonn acid copolymers, can be selected those one, or two or more kinds.

Examples of the nonionic water-soluble polymer include polyvinyl alcohol or a derivative thereof; starch derivatives such as oxidized starch, etherified starch and phosphate esterified starch; polyvinyl pyrrolidone such as polyvinyl pyrrolidone or polyvinyl pyrrolidone obtained by copolymerizing vinyl acetate. Derivatives; cellulose derivatives such as carboxymethylcellulose and hydroxymethylcellulose; polyacrylamide or a derivative thereof; polymethacrylamide or a derivative thereof;
Gelatin, casein and the like can be mentioned, and one or more of these can be selected. The use amount of the dispersant is not particularly limited, but is usually 0.02 to 20% by mass based on the total mass of the monomers to be (co) polymerized.

As the initiator used for the polymerization, a usual radical initiator can be used, and specific examples include, for example,
Hydrogen peroxide; persulfates such as ammonium persulfate and potassium persulfate; cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide;
t-butylperoxy-2-ethylhexanoate, t
Organic peroxides such as -butylperoxybenzoate and lauroyl peroxide; azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (N -Phenylamidino) propane] dihydrochloride, 2,2'-azobis {2-
[N- (4-chlorophenyl) amidino] propane dihydrochloride, 2,2′-azobis {2- [N- (4-hydroxyphenyl) amidino] propane} dihydrochloride, 2,
2'-azobis [2- (N-benzylamidino) propane] dihydrochloride, 2,2'-azobis [2- (N-allylamidino) propane] dihydrochloride, 2,2'-azobis {2- [ N- (2-hydroxyethyl) amidino] propane dihydrochloride, 2,2'-azobis {2-methyl-N
-[1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide {, 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide}, 2,2′-azobis [2-methyl-N- [2-hydroxyethyl) propionamide], 2,2′-azobis (isobutylamide)
Redox by combination of azo compounds such as dihydrate; or a metal ion such as iron ion and a reducing agent such as sodium sulfoxylate, formaldehyde, sodium pyrosulfite, sodium bisulfite, L-ascorbic acid, Rongalite, etc. Initiators and the like can be mentioned, and one or more of these can be selected. In the present invention, in particular, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (N-phenylamidino) propane] dihydrochloride, 2,2′-azobis ｛2 -[N- (4-chlorophenyl) amidino] propane dihydrochloride, 2,2'-azobis} 2- [N- (4-
Hydroxyphenyl) amidino] propane dihydrochloride,
2,2′-azobis [2- (N-benzylamidino) propane] dihydrochloride, 2,2′-azobis [2- (N-allylamidino) propane] dihydrochloride, 2,2′-azobis ｛2 -When an initiator having an amidino group such as [N- (2-hydroxyethyl) amidino] propane dihydrochloride is used, the (co) polymer can be cationically prepared without using a monomer having an amino group or the like. Can be provided.

The amount of general initiator used is from 0.1 to 5% by weight, based on the total weight of the monomers to be (co) polymerized. Also, if necessary, t-dodecyl mercaptan,
Mercaptans such as n-dodecyl mercaptan, allyl compounds such as allylsulfonic acid, methallylsulfonic acid and their soda salts can also be used as molecular weight regulators.

[Content of Cationic Organic Particles] The content of the cationic organic particles in the layer containing the cationic organic particles of the present invention is preferably 31 to 100% by mass.
More preferably, it is 51 to 100% by mass, still more preferably 71 to 100% by mass. At 31% by mass or more,
The ink dye is sufficiently fixed, and the color density and water resistance are good.

[Other Additives] The layer containing the cationic organic particles of the present invention may contain a polymer having a binder function for the purpose of improving surface strength and gloss. Examples of the polymer having a binder function include a water-soluble polymer and an aqueous dispersion of a water-insoluble polymer. This is described in detail below.

Examples of the water-soluble polymer include cationic water-soluble polymers such as cationized polyvinyl alcohol, cationized starch, cationized polyacrylamide, cationized polymethacrylamide, polyamide polyurea, polyethyleneimine, allylamine and salts thereof. Copolymer, epichlorohydrin-dialkylamine addition polymer, diallylalkylamine or its salt polymer, diallyldialkylammonium salt polymer, diallylamine or its salt and sulfur dioxide copolymer, dilyldialkylammonium salt-sulfur dioxide copolymer Polymers, copolymers of diallyldialkylammonium salts with diallylamine or salts or derivatives thereof, polymers of quaternary salts of dialkylaminoethyl (meth) acrylate, diallyldialkylammonium Salt-acrylamide copolymer,
An amine-carboxylic acid copolymer and the like can be mentioned.

Further, it is a nonionic water-soluble polymer,
Polyvinyl alcohol or derivatives thereof; starch derivatives such as oxidized starch, etherified starch, and phosphated starch; polyvinylpyrrolidone derivatives such as polyvinylpyrrolidone or polyvinylpyrrolidone copolymerized with vinyl acetate; derivatives thereof such as carboxymethylcellulose and hydroxymethylcellulose Cellulose derivatives; polyacrylamide or derivatives thereof; polymethacrylamide or derivatives thereof; gelatin, casein and the like.

Examples of the aqueous dispersion of the water-insoluble polymer include, for example, cationic and / or nonionic acrylic polymers (polymers or copolymers of acrylate and / or methacrylate), MBR polymers ( Methyl methacrylate-butadiene copolymer), S
An aqueous dispersion of a BR-based polymer (styrene-butadiene copolymer), a urethane-based polymer, an epoxy-based polymer, an EVA-based polymer (ethylene-vinyl acetate copolymer), and the like can be given.

In particular, an aqueous dispersion of polyvinyl alcohol, cationized polyvinyl alcohol, or an acrylic polymer (a polymer or copolymer of an acrylate ester and / or a methacrylate ester) is preferred because of its excellent yellowing resistance. In the case of an aqueous dispersion, the glass transition temperature of the polymer is preferably 60 ° C. or lower. The lower limit of Tg is -10C. The polymer described here is added to give a binder function, and is not used for the purpose of forming voids like cationic organic particles. Therefore, a polymer having a different property such as Tg is used.

The amount of the polymer having a binder function to be used is preferably 0 to 20 parts by mass with respect to the cationic organic particles. If the amount is more than 20 parts by mass, voids may be easily reduced and ink absorbency may be reduced.

Further, the layer containing the cationic organic particles of the present invention may contain inorganic particles. As the inorganic particles, specifically, for example, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc hydroxide, zinc sulfide, carbonate Zinc, hydrotalcite, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica,
Examples include colloidal silica, alumina, colloidal alumina, pseudoboehmite, aluminum hydroxide, lithopone, zeolite, and magnesium hydroxide. In order to obtain a high porosity and improve the ink absorbency, silica or alumina is preferable, and more preferably, the primary particle diameter is 100 n.
m or less. The lower limit is about 5 nm.

In the case where the layer containing the cationic organic particles of the present invention contains these inorganic particles, the amount of the inorganic particles is 1 to 40 with respect to 100 parts by mass of the cationic organic particles.
It is part by weight, preferably 1 to 20 parts by weight. When the amount of the inorganic particles exceeds 40 parts by mass with respect to 100 parts by mass of the cationic organic particles, the discoloration resistance and yellowing resistance may decrease. In addition, the cationic organic particles of the present invention are excellent in ink absorbency and gloss even if they do not substantially contain inorganic particles, so that the addition of inorganic particles causes a decrease in fading and yellowing resistance. Therefore, it is preferable not to contain inorganic particles.

Furthermore, in the layer containing the cationic organic particles of the present invention, an antistatic agent, an antioxidant, a dry paper strength enhancer, a wet paper strength enhancer, a waterproofing agent, a preservative, an ultraviolet ray Absorbers, light stabilizers, fluorescent brighteners, coloring pigments, coloring dyes, penetrants, foaming agents, release agents, foam inhibitors, defoamers, flow improvers, thickeners, pigment dispersants, It may contain a cationic fixing agent and the like.

[Structure of Recording Sheet] A preferable example of the structure of the recording sheet in the present invention is that a layer containing cationic organic particles is used as a layer related to ink reception, more preferably. Preferably, the outermost layer is on the recording surface side of the recording sheet. In addition, it is possible to provide a conventionally used gloss layer mainly composed of fine-particle silica, alumina or the like on the layer containing the cationic organic particles of the present invention. Since the yellowing may decrease, the layer containing the cationic particles is preferably the uppermost layer.

The amount of the layer containing the cationic organic particles of the present invention is usually 1 basis weight on a sheet-like support.
To 300 g / m ² , but is not particularly limited. The recording sheet of the present invention can also be obtained by providing an ink receiving layer having excellent ink absorbency on a support, and further providing a layer containing the cationic organic particles of the present invention on the ink receiving layer. is there.

[Type of Sheet Support] In the present invention, the support may be a support conventionally used for an ink jet recording sheet, for example, plain paper, art paper, coated paper, cast-coated paper, resin-coated paper, resin Paper support such as impregnated paper, uncoated paper, coated paper, paper support coated on both sides with polyolefin, plastic support, non-woven fabric, cloth, woven fabric, metal film, metal plate, and composite of these bonded together A support can be used.

Examples of the plastic support include plastic sheets and films such as polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, polyvinyl chloride, polyvinylidene chloride, polyimide, polycarbonate, cellophane, and polynylon. Are preferably used. These plastic supports can be properly selected from transparent, translucent and opaque ones depending on the application.

It is also preferable to use a white plastic film for the support. Examples of the white plastic support include a plastic containing a small amount of a white pigment such as barium sulfate, titanium oxide, and zinc oxide, a foamed plastic support having a large number of fine voids to impart opacity, and a white plastic support. A support provided with a layer having a pigment (titanium oxide, barium sulfate) can be used.

In the present invention, the shape of the support is not limited, but in addition to the commonly used films, sheets, plates and the like, columns such as beverage cans, discs such as CD and CD-R, etc. Others having a complicated shape can also be used as the support.

[Method of Manufacturing Recording Sheet] In the recording sheet of the present invention, a coating composition containing cationic organic particles is applied to one or both sides of a sheet-like support and dried to form a layer. It is manufactured by doing. There is no limitation on the coating method of the coating liquid, for example, an air knife coater, a roll coater, a bar coater, a blade coater, a slide hopper coater, a gravure coater, a flexographic gravure coater, a curtain coater, an extrusion coater, a floating knife coater, a comma coater, A conventionally known coating method such as a die coater can be used. There is also no particular limitation on the processing method for imparting gloss.For example, general calendar processing, that is, using a calender such as a super calender or a gloss calender, by passing between rolls under pressure or temperature, is performed. A conventionally known method for smoothing the layer surface can be used.

In addition, cast coating methods such as a direct method, a coagulation method, a rewetting method (rewetting method), and a precast method, which are generally performed in the production of cast coated paper for printing, can also be preferably used. The cast coating method is a method in which a coating layer on a support is placed in a wet state, the layer is pressed against a heated mirror-finished roll, and the mirror surface of the roll is transferred to the layer to obtain gloss. It is dried while in contact with the roll. Here, the direct method is a method in which the coating layer is pressed against a heated mirror roll in an undried state and dried, and the rewet method is a method in which after drying the coating layer, the coating layer is added to a liquid mainly composed of water. Is re-wetted, pressed against a heated mirror roll and dried. As a method for producing a recording sheet in the present invention, a direct coating method or a cast coating method by a rewetting method is preferably used.

The pressure at the time of pressure contact, the temperature of the mirror roll, the coating speed, and the like in the cast coating method are appropriately selected. In particular, the temperature of the mirror roll is a temperature lower than the glass transition temperature of the cationic organic particles, usually 3 times the glass transition temperature.
Preferably, the temperature is lower by ４０40 ° C. When the temperature of the mirror roll is equal to or higher than the glass transition temperature of the cationic organic particles, voids are likely to decrease, and ink absorption may decrease.

[0062]

EXAMPLES The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples.
Parts and% shown in Examples are parts by mass and% by mass unless otherwise specified.

Example 1 <Preparation of Cationic Organic Particles> 195.9 parts of deionized water and 0.1% of stearyltrimethylammonium chloride
Part was charged into a reaction vessel, and heated to 70 ° C. under a nitrogen stream,
0.6 parts of 2,2'-azobis (2-amidinopropane) dihydrochloride was added. Separately, 74.0 parts of methyl methacrylate, 10.0 parts of n-butyl acrylate
Parts, 16.0 parts of a methyl chloride quaternary salt of N, N-dimethylaminopropylacrylamide in 40 parts of deionized water.
The emulsified mixture was emulsified using 3 parts, and the emulsified mixture was dropped into the reaction vessel in 4 hours, and then kept at the same temperature for 4 hours. Subsequently, 2,2′-azobis (2-
0.1 part of (amidinopropane) dihydrochloride was added, and the mixture was kept at the same temperature for 3 hours to complete the polymerization. as a result,
An emulsion composition in which the cationic organic particles were dispersed in water was obtained. The nonvolatile content was 30%, the pH was 5, the average particle size was 199 nm by light scattering measurement, and the glass transition temperature obtained from a DSC curve based on JIS K 7121 was 85.0 ° C. Met.

<Preparation of Recording Sheet> Basis weight 105 g / m ²
A high quality paper is coated with an emulsion composition in which cationic organic particles are dispersed in water so as to have a coating amount of 20 g / m ^{2 in} a completely dry state, and cast coating method, specifically, surface temperature Is applied to a mirror roll maintained at 80 ° C. with a linear pressure of 1
It was dried while being pressed at 00 kg / cm. as a result,
The recording sheet of Example 1 was obtained.

[Example 2] <Preparation of recording sheet> 100 parts of fine particle silica and complete soap
Add 20 parts of polyvinyl alcohol to water and mix and stir
Thus, a coating composition having a solid content of 15% was obtained. This coating composition
Is the basis weight of 105 g / m^Two20 g /
m^TwoAnd dried at 120 ° C for 1 minute
I let it. The coating layer becomes an ink receiving layer but has a rough surface,
The gloss at 75 ° in this state was 23. Further
On the upper layer, the cationic organic particles prepared in Example 1
6 g of an emulsion composition in which water is dispersed in water
/ M ^TwoAnd apply the cast coating
Method, specifically, a mirror surface with a surface temperature kept at 80 ° C.
While pressing it at a linear pressure of 100 kg / cm.
Was. As a result, a recording sheet of Example 2 was obtained.

Comparative Example 1 <Preparation of Anionic Organic Particles> 195.9 parts of deionized water and 0.1 part of sodium dodecylbenzenesulfonate were charged into a reaction vessel and heated to 70 ° C. under a nitrogen stream. 0.5 parts of potassium persulfate was added. Separately, 74.0 parts of methyl methacrylate, 10.
0 parts and 16.0 parts of methacrylic acid are emulsified in 40 parts of deionized water using 0.3 part of sodium dodecylbenzenesulfonate to form an emulsified mixture, and the emulsified mixture is dropped into the reaction vessel in 4 hours. Thereafter, the temperature was further maintained at the same temperature for 4 hours to complete the polymerization. As a result, an emulsion composition in which anionic organic particles are dispersed in water is obtained.
0%, pH2, average particle size 120n by light scattering measurement
m and the glass transition temperature determined from a DSC curve based on JIS K 7121 were 86.2 ° C.

<Preparation of Recording Sheet> The preparation of the recording sheet of Example 1 was repeated except that the emulsion composition in which the cationic organic particles were dispersed in water was replaced with the emulsion composition in which the anionic organic particles were dispersed in water. The recording sheet was produced in exactly the same manner as in <>. As a result, Comparative Example 1
Was obtained.

Comparative Example 2 In the production of the recording sheet,
A recording sheet was produced in exactly the same manner as in Comparative Example 1 except that the surface temperature of the mirror roll was 100 ° C. as a result,
The recording sheet of Comparative Example 2 was obtained.

Comparative Example 3 <Preparation of Recording Sheet> 100 parts of finely divided silica and 20 parts of completely saponified polyvinyl alcohol were added to water and mixed and stirred to obtain a coating composition having a solid content of 15%. This coating composition was applied to a high-quality paper having a basis weight of 105 g / m ² in an absolutely dry state at 20 g / m
It was coated so as to have a coating amount of m ² and dried at 120 ° C. for 1 minute. As a result, a recording sheet of Comparative Example 3 was obtained.

[Evaluation Method] Table 1 shows the quality evaluation results of the recording sheets. The evaluation was performed by the following method. <Measurement method of liquid absorption amount> The measurement of the liquid absorption amount was performed by FIBRO DAT (Dynamic Absorption Characteristics Tester) 1100 DAT MK.
Liquid absorption volume expressed in volume units (μl)
And the liquid absorption amount per unit area (μl / cm ² ). Specifically, first, 4 μl of pure water was dropped on the surface of the sample, and the state after the drop was video-shot. Thereafter, the amount of liquid remaining on the sample surface was calculated from the contact angle and the diameter of the droplet that was deposited 0.1 seconds after the video image, and the amount of liquid absorption was calculated from the difference between this amount and the amount of the dropped droplet. . Furthermore, by dividing this value by the contact area calculated from the diameter of the deposited droplet,
The liquid absorption amount per unit area (μl / cm ² ) was calculated.
The specific calculation formula is as follows. Liquid absorption per unit area (μl / cm ² ) = liquid absorption (μ
l) / [(droplet diameter (cm) / 2) ² × π]

<Gloss Measurement Method> Gloss was measured according to JIS.
Based on Z8741, the glossiness of the recording sheet surface at 75 ° was measured using a gonio-gloss meter GM-3D type (manufactured by Murakami Color Research Laboratory).

<Method for Measuring Coloring Density> A commercially available ink jet printer (PM2000, manufactured by Seiko Epson Corporation)
Using C), solid printing of black ink was performed, and the optical reflection density of the solid portion was measured with a Macbeth densitometer (RD-918).

<Method of Measuring Ink Absorbability> A commercially available ink jet printer (PM20, manufactured by Seiko Epson Corporation)
00C), yellow ink, magenta ink,
Solid printing of cyan ink and black ink in the vertical direction,
Immediately after being discharged from the printer, the PPC paper was pressed against the upper part, and the degree of transfer of the ink to the PPC paper was visually evaluated. The evaluation criteria are as follows. ：: No transfer of ink, excellent in ink absorption. Δ: Transfer of ink was slight, but ink absorption was at a practical level. X: Transfer of ink was large, and ink absorbency was below the practical level.

<Method of Measuring Water Resistance> A commercially available ink jet printer (PM2000, manufactured by Seiko Epson Corporation)
Character printing was performed with black ink using C), and this was immersed in city water at 30 ° C. for 2 minutes to evaluate. The printed state after immersion such as bleeding was visually determined. The evaluation criteria are as follows. ：: There is almost no bleeding or change in color density. C: Bleeding and a decrease in color density were slight, but at a practical level. ×: There is bleeding and a decrease in color density, which is below the practical level.

<Method for Measuring Light Resistance> A commercially available ink jet printer (PM2000, manufactured by Seiko Epson Corporation)
Using C), solid printing of magenta ink was performed. Using a xenon fade meter, the printed recording sheet was irradiated with light for 100 hours, and the residual ratio of the optical reflection density after light irradiation before light irradiation was regarded as light resistance. The optical reflection density was measured with a Macbeth densitometer (RD-918).

<Measurement Method of Yellowing Resistance> The unprinted recording sheet was irradiated with light for 7 hours using a carbon arc fade meter, and the color difference before and after the light irradiation was measured. Color difference (ΔE) is L ^* a ^* b ^* (display method based on CIE)
ＥE = Ｅ (ＥL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ｝ ^1/2 based on the results of color measurement before and after light irradiation. The larger the color difference is, the more the color deterioration occurs.

[0077]

[Table 1]

[0078]

According to the present invention, there is provided an ink jet recording sheet having high gloss, excellent ink absorbency, and excellent color density, water resistance, light resistance and yellowing resistance, and a method for producing the recording sheet. Can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/04 CEZ D21H 19/20 A D21H 19/20 27/00 Z 27/00 C08L 101: 00 // C08L 101: 00 B41J 3/04 101Y (72) Inventor Yukie Ogawa 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. (72) Inventor Tadashi Hoshino 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. F term (reference) 2C056 EA04 EA13 FC06 2H086 BA15 BA19 BA21 BA34 BA41 4D075 BB05Z CA32 CA35 CA38 CA48 CB04 DA03 DB18 DB31 DC27 EA06 EA13 EA19 EB12 AEBA AA AA EB56 A36 A36 A36 A36 A36 A36 A36 A23 BA01 CA01 DA02 4L055 AG58 AG63 AG64 AG71 AG76 AG89 AG97 BE08 EA10 EA11 EA20 EA30 FA12 GA09

Claims (13)

[Claims] 1. An inkjet recording sheet having at least one layer containing cationic organic particles on a sheet-like support, wherein the layer containing cationic organic particles contains a void-forming component. The component is substantially a (meth) acrylate (co) polymer, a methyl methacrylate-butadiene copolymer, a styrene-
Consisting of one or more (co) polymers selected from butadiene copolymers, ethylene-vinyl acetate copolymers or olefin-based polymers, and cationic organic particles selected from materials having a cationic function. A recording sheet for inkjet recording, characterized in that: 2. The ink jet recording sheet according to claim 1, wherein the cationic organic particles are thermoplastic resin particles. 3. The cationic organic particles comprise (A) an alkyl (meth) acrylate, (B) an amino group-containing (meth) acrylate monomer, and (C) another copolymerizable monomer. The ink jet recording sheet according to any one of claims 1 to 2, which is a cationic emulsion particle obtained by copolymerization. 4. Based on the total mass of the (A) alkyl (meth) acrylate monomer, the (B) amino group-containing (meth) acrylate monomer, and (C) other copolymerizable monomers. If (A) is 30
% To 99.8% by mass, (B) 0.2% to 40%
The recording sheet for ink-jet recording according to claim 3, wherein the content of (C) is 0% to 30% by mass. 5. The ink-jet recording sheet according to claim 1, wherein the cationic organic particles have a glass transition temperature of 65 ° C. or more and 200 ° C. or less. 6. The cationic organic particle according to claim 1, wherein the weight average molecular weight is 60000 or more.
6. The ink jet recording sheet according to any one of items 1 to 5. 7. 4 μl of pure water is dropped on the recording surface of the recording sheet, and the amount of liquid absorbed after lapse of 0.1 second is from 2.00 to 2,000.
The inkjet recording sheet according to any one of claims 1 to 6, wherein the recording sheet has a gloss of 4.00 µl and a gloss at 75 ° of 50 or more. 8. 4 μl of pure water is dropped on the recording surface of the recording sheet, and the liquid absorption amount per contact area of the droplet on the recording surface 0.1 second after dropping is 0.5 to 2 μm. .00μ
The ink jet recording sheet according to claim 1, wherein the recording sheet has a density of 1 / cm ² . 9. The ink jet recording sheet according to claim 1, wherein the layer containing the cationic organic particles is an outermost layer on the recording surface. 10. The ink jet recording sheet according to claim 1, wherein the sheet support is a paper or a plastic sheet. 11. The ink jet recording sheet according to claim 1, wherein the layer containing the cationic organic particles does not contain inorganic particles. 12. A method for producing an ink jet recording sheet in which a layer containing cationic organic particles is applied by a cast coating method, wherein a coating composition containing cationic organic particles is coated on a sheet-like support. The method for producing an ink jet recording sheet according to any one of claims 1 to 11, wherein the coating is applied, and then a mirror roll is pressed against the application surface of the coating composition. 13. The method according to claim 12, wherein the surface temperature of the mirror roll is lower than the glass transition temperature of the cationic organic particles.