JP2000263926A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having surface gloss, excellent ink jet recording suitability, a sense of high grade, and excellent printer traveling property. SOLUTION: In the ink jet recording sheet comprising an undercoating layer provided as needed on a paper base material and a gloss layer further provided, a thickness of the entire sheet is 100 to 300 μm, rigidity (J. TAPPI No.40) of a printer sheet passing direction is 200 to 1,000 mgf, and the sheet is cut so that the passing direction is perpendicular to the flow direction of the base material in paper-making process.

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 sheet having a glossy surface, excellent ink-jet recording suitability, and high-quality printing excellent in printer runnability.

[0002]

2. Description of the Related Art Recording by an ink jet printer is as follows.
It is used in various fields because of low noise, high-speed recording, and easy multicoloring. As the ink jet recording paper, high quality paper devised to be rich in ink absorbency, coated paper having a surface coated with a porous pigment, or the like is applied. By the way, all of these papers are mainly so-called matte ink jet recording papers having low surface gloss, and therefore, there is a demand for ink jet recording papers having high surface gloss and excellent appearance. As a method for solving the above-mentioned problem, a copolymer having a glass transition point of 40 ° C. or higher obtained by polymerizing a monomer having an ethylenically unsaturated bond on a base paper provided with an undercoat layer mainly containing a pigment and an adhesive. A coating liquid containing the coalescing composition as a main component is applied to form a coating layer for casting, and the coating layer for casting is pressed against a heated mirror-surface drum while the coating layer is in a wet state, and is finished by drying. The present inventors have found that a cast paper for ink jet recording having both excellent gloss and excellent ink absorbency can be obtained, and proposed as Japanese Patent Application Laid-Open No. 7-89220.

In recent years, with the progress of the ink jet recording apparatus, it has become possible to produce a recorded image approaching that of a silver halide type photograph. For this reason, gloss, recording quality, comparable to photographic paper,
There is a need for texture recording paper. However, in order to give the texture of photographic paper, the thickness and rigidity of the paper are required.However, if the thickness and rigidity are close to those of photographic paper, there is a problem in that the runnability when printing with a printer is reduced. Comes with it.

[0004]

The present invention relates to an ink jet recording paper having a glossy surface, excellent ink jet recording suitability, and a high-grade feeling excellent in printer runnability.

[0005]

The present invention includes the following aspects. [1] In the inkjet recording paper provided with a gloss layer on the recording surface on a paper base material provided with an undercoat layer as required, the total thickness of the inkjet recording paper is 100 to 300 μm.
And the stiffness in the printer paper passing direction (J. TAPPI N
o. 40) is 200 to 1000 mgf, and is cut so that the paper passing direction of the printer is perpendicular to the flow direction during papermaking of the paper base material. [2] A coating liquid containing a resin and, if necessary, a pigment is applied on a paper base material provided with an undercoat layer as necessary, and while the coating layer is in a wet state, or during rewetting. After that, the inkjet recording paper according to [1], wherein a gloss layer formed by pressing and drying the heated mirror-surface drum is provided. [3] 75 degree glossiness specified in JIS Z8741 is 30% or more [1] or [2]
The ink jet recording paper according to the above.

[4] An ink jet according to [1], [2] or [3], wherein at least one undercoat layer containing a pigment and an adhesive is provided between the glossy layer and the paper substrate. Recording sheet. [5] The ink jet recording paper according to [4], wherein the pigment contained in the undercoat layer is at least one selected from amorphous silica, aluminum oxide, zeolite, and synthetic smectite. [6] The gloss layer is obtained by polymerizing a monomer having an ethylenically unsaturated bond, and has a glass transition point of 40 ° C. or more (co) polymer or a composite of the (co) polymer and colloidal silica, or [1], [2], [3], which comprises a (co) polymer and colloidal silica.
The inkjet recording paper according to [4] or [5]. However, the (co) polymer indicates a polymer or a copolymer. [7] The gloss layer contains a pigment and an adhesive, and contains, as the pigment, fine silica particles having an average primary particle diameter of 3 nm or more and 40 nm or less and an average secondary particle diameter of 10 nm or more and 500 nm or less. [1],
The inkjet recording paper according to [2], [3], [4], [5] or [6].

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper base material used in the present invention is composed mainly of wood pulp and, if necessary, pigment. As the wood pulp, various chemical pulp, mechanical pulp, recycled pulp and the like can be used. The degree of beating of these pulp can be adjusted with a beater in order to adjust paper strength, suitability for papermaking, and the like. The pigment (filler) is blended for the purpose of imparting opacity or the like or adjusting the ink absorption, and calcium carbonate, talc, calcined kaolin, silica, zeolite, titanium oxide, etc. can be used. The amount of the pigment (filler) is preferably about 1 to 20% by weight. If the amount is too large, the paper strength may decrease.

As auxiliaries, sizing agents, fixing agents, paper strength agents, cationizing agents, retention agents, dyes, fluorescent whitening agents and the like can be added. Further, in the size press step of the paper machine, starch, polyvinyl alcohol, cationic resin and the like can be applied and impregnated to adjust the surface strength, sizing degree, and the like. The size is preferably about 1 to 200 seconds. If the degree of size is low, there may be a problem in operation such as wrinkles during coating, and if it is high, curl or cockling after printing may be remarkable due to reduced ink absorbency.

For the purpose of imparting a sense of quality, stiffness, and feel close to that of photographic paper, the total thickness of the ink jet recording paper of the present invention must be 100 to 300 μm, and preferably 150 to 250 μm. If it is less than 100 μm,
The paper is stiff and difficult to handle, giving a thin impression, and lacks luxury. In addition, traces (running traces, spur traces) of the feed roll are easily formed when printing is performed, and cockling (a phenomenon in which the paper expands due to the ink absorbed by the paper base material and the paper is blurred) easily occurs. If it exceeds 300 μm, the paper will be too stiff and the printer runnability will be reduced. Therefore, the basis weight of the paper substrate, depending on the thickness of the bulk density (density) and the coating layer is preferably about 70~250g / m ^2, more preferably at about 100 to 200 g / m ² is there. The tension is not particularly limited, but is about 0.6 to 1.2.

As described above, excellent recording images can be obtained with ink jet recording paper provided with a gloss layer on the surface,
The glossy surface is hard to slip. This is presumed to be due to a small number of protrusions on the surface of the gloss layer and a large contact area. For this reason, when a large number of ink jet recording sheets are stacked, the frictional force between the front and back of the sheets increases. Therefore, when the top surface of the paper is fed by the pickup roll of the printer, multiple papers are fed or the paper is not fed due to the large frictional force between the front and back. It is thought that the problem of sex will arise.

Although the printer traveling property depends on the transport mechanism of the printer, the frictional force between the pickup roller of the printer and the paper surface (higher is better), the frictional force between the front and back of the paper (lower is better), the paper Stiffness (lower is better)
Affected by In the case of inkjet recording paper having a glossy layer on the surface, the glossy surface is hard to slip. For this reason, although the above results are likely to give good results, they cause a problem and the printer running property tends to decrease. However, by adjusting the stiffness to an appropriate value, it is possible to improve the running property of the printer by improving the penetration into the pickup roll and the transportability.

Usually, in a printer, for example, in the case of A4 size, a rectangular shape is conveyed in a long side direction (length direction). In such a recording method, the paper passing direction is A
It is the long side direction of the 4 size. For the purpose of imparting good printer runnability, in the ink jet recording paper of the present invention, the stiffness (J. TAP PINN) in the paper passing direction of the printer is used.
o. 40) needs to be adjusted to 200 to 1000 mgf, preferably 300 to 800 mgf. 20
If it is less than 0 mgf, the waist is weak and it is difficult to handle, and lacks a sense of quality. On the other hand, if it exceeds 1000 mgf, a problem arises in the printer runnability.

The stiffness of the ink jet recording paper is greatly affected by the stiffness of the paper base material. And the rigidity of the paper substrate is
It is affected by basis weight, tension, beating degree of pulp used for papermaking, pulp tree type, aspect ratio (degree of orientation of pulp fibers) during papermaking, ash content, and the like. Generally, the higher the paper thickness, the higher
The higher the intensity, the lower the tendency. The tension can be increased by, for example, applying a super calender. The beating degree can be adjusted by a beating machine, and the beating degree (freeness) of pulp is 250 to 550 ml (CS
F: about JIS P-8121). When an internal pigment is present, the content tends to decrease as the content increases. The ash content is preferably about 1 to 20%. When there is a fiber orientation, the stiffness about the direction in which the fiber orientation is strong is higher than the stiffness about the direction perpendicular to the direction in which the fiber orientation is strong. In addition, when the paper is made with a normal paper machine, the fibers are easily oriented in the flow direction of the paper machine.

According to the present invention, it is possible to achieve both high quality and printer runnability in glossy inkjet paper by keeping the paper thickness and rigidity within a predetermined range. The stiffness specified in the present invention is the stiffness in the printer paper passing direction which affects the printer running property, and the stiffness in the direction perpendicular to the printer paper passing direction is not particularly limited. Generally, the MD has a high rigidity in the longitudinal direction (flow direction of the paper machine; referred to as MD) and in the horizontal direction (direction perpendicular to the flow of the paper machine; referred to as CD). With the paper thickness in the range of the present invention, even if the basis weight, the tension, the papermaking conditions, and the like of the paper base material are adjusted, the M
In many cases, the stiffness of D becomes too high and deviates from the range of the stiffness desired in the present invention. Even in such a case, the stiffness of CD can be adjusted to an appropriate range. In this case, by cutting the paper so that the paper passing direction is CD,
The effects of the present invention can be obtained.

In the present invention, a gloss layer can be provided directly on the paper substrate, but it is preferable to provide one or more undercoat (recording) layers. Even when the gloss fixing layer has a low ink fixing / absorbing ability, a sufficient ink fixing / absorbing property can be obtained by the undercoat layer. When the glossy layer has an ink fixing / absorbing ability, the provision of an undercoat layer further promotes the ink fixing / absorbing. The undercoat (recording) layer provided on the paper substrate is mainly composed of a pigment and an adhesive. Examples of pigments include kaolin, clay, calcined clay, amorphous silica, zinc oxide, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, aluminum silicate, alumina, colloidal silica, zeolite, sepiolite, smectite, synthetic smectite, and silicic acid. Magnesium, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene-based plastic pigment,
Urea resin-based plastic pigments, benzoguanamine-based plastic pigments, and the like, various publicly known pigments in the general coated paper manufacturing field can be used.
It is preferable to use amorphous silica, aluminum oxide, zeolite, synthetic smectite, or the like as at least a part thereof in order to make the structure of the coating layer porous and excellent in ink absorption.

The average particle size of the pigment contained in the undercoat recording layer (the average particle size of the secondary particles of the pigment forming aggregated secondary particles) is preferably from 0.1 μm to 15 μm, and more preferably from 1 μm to 10 μm. The following are more preferred. If the average particle size is less than 0.1 μm, the ink absorbency will decrease, causing bleeding and uneven ink absorption, making it difficult to obtain the desired image quality. Further, when the average particle size of the pigment is 1
If it exceeds 5 μm, the gloss will be reduced and the color developability will be reduced, making it difficult to obtain the desired image quality. As the above-mentioned pigments, those having different types and average particle diameters can be used in combination.

Examples of the adhesive include proteins such as casein, soybean protein, and synthetic protein; various starches such as starch and oxidized starch;
Polyvinyl alcohols, cellulose derivatives such as carboxymethylcellulose and methylcellulose, styrene-
Butadiene copolymer, conjugated diene-based polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, vinyl-based polymer latex such as ethylene-vinyl acetate copolymer, etc. are generally used for coated paper. Conventionally known adhesives may be used alone or in combination. The amount of the adhesive is 1 to 200 parts by weight, more preferably 2 to 10 parts by weight, per 100 parts by weight of the pigment.
It is adjusted in the range of 0 parts by weight. Here, if the amount of the adhesive is small, the strength of the recording layer may be weakened, the surface may be easily damaged, or 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 undercoat layer contains a cationic compound in an amount of 1 to 1 part by weight based on 100 parts by weight of the pigment for the purpose of improving image density, water resistance of a printed image and gloss after the gloss layer is provided.
It can be used in an amount of 00 parts by weight, more preferably 5 to 60 parts by weight. 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. When polymerizing a cationic resin, such a cationic organic pigment is used as a crosslinked resin by copolymerizing a polyfunctional monomer, or a reactive functional group (hydroxyl group, carboxyl group, amino group, acetoacetyl group, etc.). A cross-linking agent is added to the cationic resin having the above as required, and the cross-linked resin is formed by means of 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
02 copolymer, 8) diallylamine salt-S02 copolymer, 9) dimethyldiallylammonium chloride polymer, 10) allylamine salt polymer, 11) dialkylaminoethyl (meth) acrylate quaternary salt polymer, 1
2) Cationic compounds such as acrylamide-diallylamine salt copolymer.

Various auxiliaries such as dispersants, thickeners, defoamers, coloring agents, antistatic agents and preservatives, which are used in the production of general coated paper, are appropriately added to the undercoat layer. The composition for each recording layer composed of the above-mentioned materials is generally adjusted to a solid content concentration of about 5 to 65% by weight and has a basis weight of about 20 to 40%.
It is applied on a substrate of about 0 g / m ² . The coating amount is about 1 to 50 g / m ² by dry weight, and more preferably ² to 30 g.
/ M ² . Coating is performed and dried by various known and publicly used coating devices such as 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, a lip coater, and a curtain coater. .
Further, if necessary, the recording layer may be subjected to a smoothing process such as super calendering or brushing after drying.

A gloss layer is provided directly on a paper substrate or on an undercoat layer comprising a pigment and an adhesive provided on the paper substrate.
The glossy layer is preferably made porous or liquid-permeable so as not to impair the gloss so that the ink can be quickly passed or absorbed. In order to achieve this, it is preferable to incorporate a pigment. In addition, in a mode in which a gloss layer is provided using a heated mirror drum, as long as the gloss is not reduced,
It is preferable to select drying conditions so that the glossy layer is not completely formed. The gloss layer contains a resin and, if necessary, a pigment. As the resin for the gloss layer, water-soluble resins (for example, polyvinyl alcohol, cation-modified polyvinyl alcohol,
Conjugated dienes such as polyvinyl alcohols such as silyl-modified polyvinyl alcohol, casein, soy protein, synthetic proteins, starch, cellulose derivatives such as carboxymethylcellulose and methylcellulose), styrene-butadiene copolymer and methylmethacrylate-butadiene copolymer Water-dispersible resins such as polymer latex, vinyl-based copolymer latex such as styrene-vinyl acetate copolymer, water-based acrylic resin, water-based polyurethane resin, water-based polyester resin, etc. Resins (adhesives) are used alone or in combination.

When a gloss layer is formed mainly of resin,
In particular, it is preferable that a polymer or a copolymer obtained by polymerizing a monomer having an ethylenically unsaturated bond (hereinafter, referred to as an ethylenic monomer) as a main component is used as a main component. Such polymers include, for example, methyl acrylate, ethyl acrylate,
Butyl acrylate, 2 ethylhexyl acrylate,
Lauryl acrylate, 2-hydroxyethyl acrylate, acrylates having an alkyl group carbon number of 1 to 18 such as glycidyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Alkyl group carbon number such as glycidyl methacrylate is 1 to 1
18 methacrylates, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, acrylamide, N-methylol acrylamide,
Polymers obtained by polymerizing ethylenic monomers such as ethylene and butadiene are exemplified.

The polymer may be a copolymer using two or more kinds of ethylenic monomers as needed, or may be a polymer or a substituted derivative of the copolymer. Incidentally, examples of the substituted derivative include, for example, those having a carboxyl group or those having been rendered alkali-reactive. It is preferable to use a composite of the above polymer or copolymer and colloidal silica because the balance between gloss and ink absorbency is particularly excellent. At this time, the proportion of the ethylenic monomer to the colloidal silica is desirably about 5/95 to 95/5 by weight. If the proportion of colloidal silica exceeds 95, the amount of colloidal silica not contributing to the composite increases,
The gloss may decrease, and if it is less than 5, the desired effect may not be obtained. Complexing with colloidal silica is carried out by polymerizing the above-mentioned ethylenic monomer with a silane coupling agent or the like in the presence of colloidal silica, and forming Si-O-
An R-bond (R: a polymer component) is used to form a composite or, if necessary, a polymer resin modified with a silanol group or the like is reacted with colloidal silica to form a Si—O—R bond (R:
(Polymer component) to form a composite.

In an embodiment in which a gloss layer is provided by a method using a heated mirror-surface drum as described later, the above-mentioned copolymer preferably has a glass transition point of 40 ° C. or higher, and is 50 to 100 ° C.
C. is more preferred. When the glass transition point is low, film formation proceeds excessively during drying, and the porosity of the surface is reduced. As a result, the ink absorption rate may be 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.

When a pigment is blended in the glossy layer, the pigments include those exemplified as pigments for the undercoat layer. Colloidal silica, amorphous silica, aluminum oxide, and the like in terms of gloss, transparency, and ink absorbability. , Zeolite,
Synthetic smectite, alumina silicate and the like are preferred.
In the gloss layer, it is preferable to increase the recording density by improving gloss and transparency. The average particle size of the pigment (secondary particles in the case of aggregated secondary particles) 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 may be reduced, and the effect of improving the print density cannot be obtained. In particular, the average primary particle diameter of the pigment is 3 nm or more and 40 nm or more.
Below, the average particle diameter of the secondary particles is 10 nm or more and 500 n
When silica fine particles having a particle size of m or less are used, glossiness and ink absorbency tend to be particularly excellent. Preferably,
It is a silica fine particle having an average particle diameter of primary particles of 3 nm or more and 40 nm or less and an average particle diameter of secondary particles of 10 nm or more and 400 nm or less. In this embodiment, when the gloss layer is formed with a pigment as a main component (50% or more), ink absorbency is particularly excellent.

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 combined with the transparency of the glossy layer. Will be extremely excellent. The glossy layer may contain a cationic compound in an amount of 1 to 100% by weight, more preferably 5 to 50% by weight, for the purpose of improving image density and print image water resistance. As the cationic compound, those exemplified as the cationic compound blended in the undercoat layer can be used. The coating liquid for the glossy layer includes various other additives such as antifoaming agents, coloring agents, antistatic agents, preservatives and dispersants, and thickeners which are used for ordinary printing coated paper and inkjet paper. An agent is appropriately added. The ink jet recording medium obtained in this way solves the above-mentioned problems, but it is possible to obtain more excellent glossiness by a casting method, a film forming method and the like.

The glossy layer is coated with the above-mentioned coating solution, and is then wetted (containing at least water having plasticity), or once dried and rewet. Thereafter, it is preferable to employ a method of finishing by pressing and drying the heated mirror-surface drum (casting method), and an ink jet recording sheet having both excellent gloss and ink absorbability can be obtained by the casting method. Examples of the casting method include a wet casting method, a rewetting casting method, and a gelling casting method. Film forming methods include
(A) The above gloss layer coating solution is applied on a paper substrate or an undercoat layer provided on the paper substrate, and a smooth film or sheet is laminated while the coating layer is in a wet state. , A method of peeling and finishing a smooth film or sheet after drying, (b) applying a coating liquid on a smooth film or sheet and applying a coating layer or a substrate surface or an undercoat to be bonded While the layer surface is in a wet state to some extent, a method of pressing against a substrate, drying and peeling a smooth film or sheet to finish can be exemplified. The surface roughness Ra of the film, mirror drum, etc. is preferably 0.5 μm or less, more preferably 0.5 μm or less.
It is not more than 05 μm.

When the above-mentioned gloss layer coating liquid is coated on the recording layer, a blade coater, an air knife coater,
Various known coating apparatuses such as a roll coater, a brush coater, a chaplex coater, a bar coater, a gravure coater, a die coater, a lip coater, and a curtain coater can be used. The coating amount of the coating liquid for the gloss layer is 0.2 to 100 g / m ^{2 as} a dry solid content, preferably 1 to 100 g / m ² .
It is 50 g / m ² . Here, if it is less than 0.2 g / m ² , the gloss may not be sufficiently obtained, and if it exceeds 100 g / m ² , the ink drying property may be poor or the recording density may be reduced. After providing a gloss layer by cast finish,
Further, a smoothing process can be performed using a super calendar or the like. 75 ° glossiness of the gloss layer surface (JIS-P8
142) In order to give the texture of photographic paper, 30
% Is appropriate, preferably 40% or more, and more preferably 50% or more.

According to the present invention, curling prevention, blocking prevention, writing property, antistatic, antistatic, high-grade feeling, and printing on the opposite side (back side of the recording paper) opposite to the side on which the gloss layer (glossy recording layer) is provided. A coating layer can be provided for the purpose of, for example, further improving running properties. Although the coating layer on the back surface is not particularly limited, for example, it is mainly composed of a resin and a pigment. Further, a polyolefin resin-containing layer can be provided by a melt extrusion lamination method.

[0030]

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. The stiffness is 20 ° C and 65% RH.
Was measured under the following environment. Preparation of paper substrate Wood pulp (LBKP; freeness 500 ml CSF) 10
Paper making consisting of 0 parts, calcined kaolin (Ansilex, Engelhard & Minerals) 9 parts, commercial sizing agent 0.05 parts, sulfuric acid band 1.5 parts, wet paper strength agent 0.5 parts, starch 0.75 parts Using the materials, paper base materials having various basis weights were manufactured by a fourdrinier paper machine. Paper base weight: 65 g / m ² , paper thickness: 85 μm, tightness: 0.7
6, Steckigt sizing degree: 3 seconds Paper base weight: 95 g / m ² , paper thickness: 125 μm, tightness: 0.
76, Steckigt sizing degree: 6 seconds Paper base weight: 114 g / m ² , paper thickness: 150 μm, tightness: 0.
76, Stekigt sizing degree: 8 seconds, paper base weight: 136 g / m ² , paper thickness: 180 μm, tightness: 0.1.
76, Stekigt sizing degree: 10 seconds Paper base weight: 155 g / m ² , paper thickness: 205 μm, tightness: 0.1.
76, Steckigt sizing degree: 12 seconds Paper base weight: 170 g / m ² , paper thickness: 225 μm, tightness: 0.
76, Stekigt sizing degree: 15 seconds Paper base weight: 208 g / m ² , paper thickness: 275 μm, tightness: 0.
76, Stekihito sizing degree: 25 seconds

Amorphous silica 1 having an average secondary particle diameter of 4.5 μm as a pigment for inkjet paper A
00 parts (trade name, Fine Seal X-45, manufactured by Tokuyama Corporation), 20 parts of silyl-modified polyvinyl alcohol (R1130 manufactured by Kuraray Co., Ltd.) as an adhesive, and dicyandiamide-based resin (trade name, Neofix E117) as a cationic resin , Manufactured by Nichika Chemical Co., Ltd.) and 5 parts of acrylamide resin (trade name, Sumiretz Resin SR1001,
15 parts of Sumitomo Chemical Co., Ltd.) and 0.5 part of sodium polyphosphate as a dispersant were added to prepare a coating liquid for an undercoat recording layer having a solid content of 18%. The coating liquid for a recording layer was coated on one side of a paper base material with an air knife coater to a dry weight of 6 g / m ² , and dried to form an undercoat recording layer.

On the other hand, styrene-2 having a glass transition point of 75 ° C.
Composite of methylhexyl acrylate copolymer and colloidal silica (dispersion of primary particles having an average particle diameter of 30 nm) (copolymer and colloidal silica are in a weight ratio of 50: 5).
0) A gloss layer coating liquid having a solid content concentration of 25%, comprising 100 parts, 5 parts of an alkyl vinyl ether / maleic acid derivative copolymer as a thickening / dispersing agent, and 1.5 parts of lecithin as a release agent, was prepared. . After applying the gloss layer coating solution on the undercoat recording layer using a roll coater, the coating solution was immediately pressed against a mirror drum having a surface temperature of 85 ° C., dried and released, and a gloss type inkjet recording was performed. I got the paper.
The coating amount of the gloss layer at this time was 6 g / m ² in terms of solid content weight.
Met.

The following coating solution for the undercoat recording layer was coated on a paper base material of inkjet paper B using an air knife coater so as to have a dry weight of 12 g / m ² and dried. Next, the following coating liquid for a gloss layer is coated on the undercoating recording layer with an air knife coater, dried for 20 seconds with cold air to be in a semi-dry state (a moisture content of 150 with respect to the absolute dry amount of the coating layer). %), And pressed against a mirror-surface drum having a surface temperature of 100 ° C., dried, and released to obtain a glossy inkjet recording paper. The coating amount of the cast coating layer at this time was 5 g / m ² in terms of solid content weight. Coating liquid for undercoat recording layer (solid content: 17%) Synthetic silica (Fine Seal X-60; manufactured by Tokuyama, average secondary particle diameter 6.0 μm, primary particle diameter 15 nm) 80
Parts, 20 parts of zeolite (ToyoBuilder; manufactured by Tosoh, average particle size 1.5 μm), 20 parts of silyl-modified polyvinyl alcohol (R1130; manufactured by Kuraray), glass transition point 7
Complex emulsion of styrene-2-methylhexyl acrylate copolymer at 5 ° C. and colloidal silica having a particle diameter of 30 nm (copolymer and colloidal silica are mixed in a weight ratio of 4%).
0:60, emulsion particle size is 80 nm) 40 parts

Coating solution for cast coating layer (solids concentration 12
%) Silica fine particles A (described below) 100 parts, diallyldimethylammonium chloride-acrylamide copolymer (trade name: PAS-J-81, manufactured by Nitto Boseki Co., Ltd.) 10
Part, cationic acrylic resin (XC-2010; Seiko Kagaku, quaternary amine-modified acrylic aqueous resin, Tg 85 ° C)
20 parts, silyl-modified polyvinyl alcohol (R113
0; Kuraray) 10 parts, release agent (stearic acid amide)
2 copies

Preparation of Silica Fine Particles A Synthetic amorphous silica (manufactured by Tokuyama Corporation, trade name: Fine Seal X-45, secondary particle size 4.5 μm, primary particle size 15)
nm) of an aqueous dispersion and a pressure homogenizer (SM
Company T, trade name: ultra high pressure homogenizer GM-1)
The pulverization operation was repeated using (pressurized 500 kg / c
m ² ). The dispersion had a primary particle size of 15 nm, an average secondary particle size of 50 nm, and a solid content of 12% after the treatment.

Example 1 Inkjet paper A was cut to A4 size using a paper base material so that the paper passing direction was CD. Comparative Example 1 Inkjet paper A was cut to A4 size using a paper base material so that the paper passing direction was MD.

Examples 2 to 5 and Comparative Examples 2 to 4 Ink-jet paper B was cut to A4 size using the paper base shown in Table 1 so that the paper passing direction was CD. Comparative Examples 5 to 8 Inkjet paper B was cut to A4 size using the paper base material shown in Table 1 so that the paper passing direction was MD. Comparative Example 9 In the inkjet paper A, a paper base was used as a paper base, and an undercoat recording layer was provided (a gloss layer was not provided).
The paper was cut into A4 size paper so that the paper passing direction was CD. Comparative Example 10 The paper substrate was used as it was, and cut into A4 size paper so that the paper passing direction was CD.

Table 1 summarizes the quality of the ink jet recording paper thus obtained. The recording sheets of Examples 1 to 5 and Comparative Examples 1 to 10 had a tension of 0.76. The quality was evaluated by the following method. The following evaluations were all performed in an environment of 20 ° C. and 65% RH. [Glossiness] A 75 ° glossiness of a blank portion of the recording surface was measured according to JIS-P8142. [Inkjet recording suitability] Printing was performed on A4 size paper using an inkjet printer BJC420J (manufactured by Canon Inc.). (Uniformity of solid printing portion) The printing unevenness (shading unevenness) of the solid printing portion in which two colors of cyan ink and magenta ink were mixed was visually evaluated. 5: Good level without printing unevenness. 1: A level at which printing unevenness is remarkable and becomes a serious problem in practical use.

(Drying property of ink) The drying property of the ink was evaluated for the solid printing portion of the mixture of two colors of the cyan ink and the magenta ink. 5: No stain at all even if touched with a finger immediately after printing. (Print density after inkjet recording) The print density of the black solid print portion was measured by Macbeth RD-914. (Cockling) Image ("High Definition Color Digital Standard Image Data ISO / JIS-SCID", p13, Image Name: Portrait, Published by Japan Standards Association)
Was printed and left for one day, and the degree of cockling was visually determined. 5: Cock ring is almost inconspicuous. 4: Cockling was slightly observed, but was not noticeable. 3: Cockling is slightly noticeable, but at a level that does not pose a problem in practical use. 2: Cockling is conspicuous, which is a practically problematic level. 1: Cockling is remarkable.

(Spur mark) Image ("High-definition color digital standard image data ISO / JIS-SCID", p1
3. After printing the image name: Portrait, issued by the Japan Standards Association, and leaving it for one day, the appearance of spur marks (a phenomenon in which the paper feed roll swells with ink and the roll mark dents form on the surface of the recording paper) The extent was visually determined. 5: Spur trace is almost inconspicuous. 4: Spurs are slightly observed, but are not noticeable. 3: Spur marks are slightly noticeable, but at a level that does not pose a problem in practical use. 2: Spur marks are conspicuous, which is a practically problematic level. 1: Cockling is remarkable. [Printer running property] Twenty sheets of paper were stacked on a printer and continuous printing was performed. When 5 sets were tested out of 1 set of 20 sheets (100 sheets in total), the number of times of unsuccessful conveyance (non-feed, double feed, defective printing position) was counted. 5: No problem at all. 4: There is no non-feeding or double feeding, but there are 1 to 5 sheets where the printing position is slightly shifted. 3: 1-5 sheets of non-feed and double feed. 2: 6-10 sheets of non-feed and double feed. 1: Non-feed, double feed or more.

[Appearance] Comprehensively observing the glossiness, touch, and stiffness of the paper on the surface, it was determined whether or not the paper had a high-grade appearance. 5: Extremely excellent. 4: Excellent. 3: Normal. 2: Slightly inferior. 1: Poor. [Comprehensive evaluation] The quality was judged comprehensively and evaluated on a five-point scale. 5: Extremely excellent. 4: Excellent. 3: Normal. 2: Slightly inferior. 1: Poor.

[0042]

[Table 1]

[0043]

According to the present invention, there is provided an ink jet recording paper which has a surface gloss, is excellent in ink jet recording suitability, and has a high quality feeling in printer runnability.

Continued on front page F-term (reference) 2C056 FC06 2H086 BA12 BA21 BA33 BA41 4L055 AG18 AG63 AG64 AG65 AG71 AG72 AG89 AG94 AG99 AH02 AH37 AJ04 BE04 BE09 EA07 EA08 EA11 FA12 FA15 FA30 GA09 GA20

Claims (3)

[Claims] An undercoat layer is provided on a paper base as needed,
Furthermore, in the inkjet recording paper provided with a gloss layer,
The thickness of the entire inkjet recording paper is 100-300μ
m, the stiffness in the paper passing direction (J. TAPPI N
o. 40) is 200 to 1000 mgf, and is cut so that the paper passing direction of the printer is perpendicular to the flow direction during papermaking of the paper base material. 2. On a paper base material provided with an undercoat layer as required,
Apply a coating solution containing a resin and, if necessary, a pigment,
2. The ink jet recording sheet according to claim 1, wherein a gloss layer formed by pressing and drying the heated mirror-surface drum while the coating layer is in a wet state or after re-wetting is provided. 3. The ink jet recording paper according to claim 1, wherein the glossiness at 75 degrees specified in JIS Z8741 is 30% or more.