JPH11301101A - Inkjet recording paper - Google Patents

Abstract

(57) [Problem] To provide an ink jet recording sheet excellent in transportability by avoiding a waving phenomenon (cockling) generated on a printing portion surface during printing and after printing by printing. Kind Code: A1 Abstract: An ink jet recording sheet comprising at least one ink receiving layer coated on a base paper. At least one or more support layers are coated on the surface opposite to the ink receiving layer surface with the base paper therebetween, and at least one of the support layers is composed of a composition mainly composed of a non-aqueous resin. The target inkjet recording paper can be obtained by setting the layer, the ink receiving layer and the base paper to specific thicknesses, and setting the outermost surface on the support layer side and the surface of the ink receiving layer to specific glossiness. .

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 for recording using ink, and more particularly to an ink jet recording sheet which avoids a phenomenon called cockling in which a printing surface which occurs during and after ink jet recording is wavy. Things.

[0002]

2. Description of the Related Art Ink-jet recording is a method in which fine droplets of ink are made to fly and adhere to recording paper such as paper by various operating principles to record images and characters. It has features such as easy multi-coloring, great flexibility in recording patterns, and no need for development-fixing. It has rapidly spread in various uses as a recording device for various figures and color images including Chinese characters. I have. Further, an image formed by the multi-color ink jet system can obtain a record comparable to multi-color printing by a plate making system or printing by a color photographic system. In addition, in applications requiring a small number of copies, it is being widely applied to the field of full-color image recording because it is less expensive than the photographic technique.

In addition, the cost of the ink jet recording apparatus has been reduced,
Because it is possible to easily obtain an image with excellent image reproducibility and color reproducibility such as sharpness and color at the level of a personal computer, an ink jet recording device can be used from a special recording device used for a specific person to a general-purpose one. In recent years, the recording apparatus has been changed, and in recent years, in particular, the ink jet recording apparatus has been further improved in definition, and the ratio of possession by an individual has been greatly increased due to the appearance of an ink jet recording apparatus that claims photographic quality at a low price. I have.

[0004] Further, with diversification of uses, they are increasingly used for large-sized posters, POP arts, and drafting applications. In these applications, the high sharpness of the ink jet can be utilized and excellent color can be obtained, so that a good image can be obtained, and the advertising effect is large. Application to these is because it is possible to easily obtain an image excellent in image reproducibility and color reproducibility such as sharpness and color at the level of a personal computer, which is a reason why ink jet recording paper is frequently used. .

[0005] Due to the high performance and diversification of applications of these ink jet recording apparatuses, the characteristics and requirements required for the ink jet recording paper have become quite high. In particular, in a recording apparatus that claims high definition of an image or a recording apparatus capable of large-format printing, the amount of ink used to form an image is considerably increased compared to the conventional one, and an ink receiving layer for absorbing the ink is used. Is improving. However, it is difficult to obtain a satisfactory image quality for a recording apparatus having a large amount of ink only by supporting the ink receiving layer as described below.
It is preferable to select a base paper that can also be a layer that absorbs ink. The fact that the base paper absorbs the ink is accompanied by the occurrence of a phenomenon called cockling in which the base paper expands and contracts with respect to the printed ink, the recording paper is distorted, and the surface of the printing portion is wavy.

This phenomenon occurs when ink is printed on recording paper and the paper is distorted due to expansion and contraction. That is, this phenomenon has occurred during ink jet recording. Therefore, during ink jet recording, a phenomenon may occur in which a recording head portion scanning on the sheet comes into contact with the surface of the sheet which is wavy due to cockling, causing a phenomenon of head rubbing. Due to the occurrence of this phenomenon, the surface of the printing portion is scraped and the printing quality is remarkably deteriorated. In addition, the recording head is clogged and printing failure occurs. Further, since the surface is still wavy even after printing, even if the image quality is high, the visual texture is significantly impaired. Therefore, occurrence of cockling is a serious problem, and it is difficult to achieve both ink absorbency and cockling.

[0007] Further, diversification of uses has also occurred with respect to the appearance of ink jet recording paper, and in addition to the conventional matte or matte paper having a dull or low appearance, art paper, coated paper, cast paper, There is a demand for glossy appearance of photographic paper and the like. This is because ink jet recording can reproduce image quality comparable to printing or photography, and there is a demand for a similar appearance.

[0010] In particular, cockling, which is an object of the present invention, is a wavy pattern generated on the surface of a printing portion of an ink jet recording paper. In the glossy recording paper, reflected light is scattered. Cockling is more noticeable than matte paper, and avoiding this is an important issue.

As a means for avoiding this phenomenon, a method of making the base paper sufficiently thick or a method of providing a back coat layer on the side opposite to the ink receiving layer via the base paper to suppress expansion and contraction of the base paper are generally performed. However, with these methods, it is difficult to completely avoid cockling in a printing apparatus in which the amount of ejected ink has recently increased. Further, in order to make the base paper thicker and to cope with the rigidity of the base paper, a considerable thickness is required, and the thickness of the recording paper usually used is 70 to 250.
This will greatly exceed the range of μm. As a result, the rigidity of the base paper is increased and the recording paper lacks flexibility,
Since the base paper is thick, transportability in the ink jet recording apparatus is reduced.

In addition, there is a method of increasing the absorption capacity of the ink receiving layer so that the ink does not reach the base paper. However, in order to increase the absorption capacity of the ink receiving layer, it is necessary to reduce the binder component in the ink receiving layer or increase the coating amount of the ink receiving layer. However, it is difficult to say that this method is a good means because the adhesive strength of the toner and the reproducibility of the image due to the thinning of the dots forming the image occur.

Further, there is a method of providing a barrier layer between the base paper and the ink receiving layer so that the printed ink does not penetrate into the base paper, and a method of providing water resistance so that the base paper does not expand and contract even if the ink penetrates. Conceivable. However, according to these methods, the ink absorption capacity of the recording paper is reduced, and ink overflow or bleeding occurs, making it difficult to obtain a good image.

[0012]

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to provide an ink jet recording medium having a printing portion having a wavy surface caused by distortion of the ink jet recording paper due to expansion and contraction of the base paper when the ink is injected into the recording paper. An object of the present invention is to provide an ink jet recording sheet having good transportability while avoiding a phenomenon called cockling.

[0013]

According to the ink jet recording paper of the present invention, at least one or more ink-receiving layers are provided on a base paper and at least one or more support layers are provided on the opposite side of the ink-receiving layer via the base paper. In the ink jet recording paper provided, at least one of the support layers is composed of a composition containing a non-aqueous resin as a main component, and 20% of the total thickness of the base paper and the ink receiving layer.
It is characterized by being provided with the above thickness, and it has been found that an ink jet recording paper having the above-mentioned disadvantages improved can be obtained.

When the thickness of the base paper is less than 30 μm, the ink absorption capacity is insufficient, and when it exceeds 200 μm, the flexibility as the ink jet recording paper is insufficient, and consequently the transportability is reduced, so that the thickness of the base paper is 30 μm. It is preferably in the range of ~ 200 [mu] m.

The outermost surface of the support layer is JIS P814
In 75 degree specular glossiness defined in 2, it is preferable that it is 70% or less, because the transportability becomes good.

The effect of avoiding cockling on ink-jet recording paper having a surface of the ink receiving layer provided on the base paper of 40% or more at 75-degree specular glossiness specified in JIS P8142 is enhanced. It is preferred.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet recording paper of the present invention will be described below in detail.

The present inventors have found that the cockling causes a large amount of ink to be injected into the recording paper by printing, causing the base paper provided with the ink receiving layer to expand and contract, causing distortion not only in the base paper but also in the ink receiving layer. Considering that the recording paper is caused to be distorted, intensive studies have been made on a method for suppressing distortion of the recording paper due to expansion and contraction of the base paper. As a result, the ink jet recording characteristics are affected by providing a support layer on the opposite side of the ink receiving layer via the base paper, and providing at least one of the support layers with a composition containing a non-aqueous resin as a main component. It has been found that distortion of the recording paper can be suppressed without any problem and cockling can be improved.

Further, the present inventors have studied the base paper on which the support layer is provided and the support layer, and the support layer has a thickness of 20% with respect to the total thickness of the base paper and the ink receiving layer.
It has been found that the effect of improving cockling during and after ink jet recording is further enhanced by being provided with the above thickness.

The improvement in cockling is indicated by the fact that the non-aqueous resin forming at least one of the support layers suppresses expansion and contraction of the base paper, and that the support layer does not expand and contract with ink. Is considered to be because the support layer does not permeate into the base paper and does not affect the properties of the base paper treated as the ink absorbing layer. In the present invention, when the thickness of the support layer is less than 20% of the total thickness of the base paper and the ink receiving layer,
It is difficult to suppress distortion of the recording paper due to expansion and contraction of the base paper, and cockling cannot be improved.

In a support layer other than a non-aqueous resin, for example, a support layer using an aqueous coating liquid containing a pigment and a binder as main components, cockling can be completely avoided in a recent recording apparatus having a large ink discharge amount. Can not. this is,
It is thought that the lack of rigidity to prevent the expansion and contraction of the base paper and the deformation of the support layer itself due to the ink penetrating through the base paper due to the absorbency caused the cockling completely. It did not lead to prevention. In addition, when the support layer is set up, the water-based coating liquid of the layer penetrates into the base paper, which may impair the ink absorbency.

In the present invention, the thickness of the base paper is 30 μm.
m to 200 μm. Cockling is a phenomenon in which base paper expands and contracts due to printed ink, and recording paper is distorted. In other words, the thinner the base paper, the greater the expansion and contraction, and consequently the worse the cockling. Therefore, the effect of avoiding cockling according to the present invention is more likely to appear as the thickness of the base paper is smaller, and the effect is particularly clear when the thickness is 200 μm or less. Here, the thickness of the base paper is 200
When the thickness is larger than μm, the effect of the present invention on cockling is hardly exhibited, and the thickness as a recording paper is increased, so that the flexibility is reduced and the transportability is also affected. On the other hand, if the thickness is less than 30 μm, the ink absorption capacity is insufficient, and sufficient printing characteristics cannot be obtained.

Further, it is important to secure the transportability of the ink jet recording paper by increasing the speed of the ink jet recording. As shown in the present invention, when the outermost surface on the support layer side is 70% or less in terms of 75 degree specular glossiness specified in JIS P8142, good transportability can be obtained. Generally, in an ink jet recording apparatus, the recording sheets are bundled and set, and recording is performed sequentially. For this reason, the slipperiness when the front and back surfaces of the recording paper are brought together greatly affects the transportability. In the present invention, it has been found that by concluding the outermost surface on the support layer side with the above-mentioned specific glossiness irrespective of the surface state of the ink receiving layer surface, that is, the matte surface or the glossy surface, it is effective in improving the transportability. did.

The support layer in the present invention means at least one or more layers provided on the opposite side of the ink receiving layer via the base paper. In particular, it is necessary that at least one layer of the support layer is composed of a composition containing a non-aqueous resin as a main component, and only when the glossiness of the outermost surface on the support layer side is in a specific range, The inkjet recording paper intended by the present invention can be obtained.

For example, a composition containing a non-aqueous resin as a main component may be directly set on the base paper, or after applying some water-based coating liquid on the base paper for curl correction, the composition may be applied to the base paper. It may be coated.

Examples of the non-aqueous resin applied to the support layer include the following substances. Polyethylene such as high-density polyethylene, low-density polyethylene, medium-density polyethylene, and linear low-density polyethylene; isotactic, syndiotactic, atactic, mixtures thereof, random copolymers with ethylene or block copolymers, etc. Polypropylene; other poly-3-methylpentene-1, polyethylene glycol terephthalate, polyvinyl chloride, polyvinylidene chloride, eval, polyisobutylene, ethylene vinyl acetate copolymer and the like can be used alone or in combination.

The support layer composed of a composition containing a non-aqueous resin as a main component can be provided by using a general laminator such as a melt extrusion die, a T die, a multilayer simultaneous extrusion die, or a hot melt coater. Since the amount of the support layer varies depending on the substance to be applied, it is preferably defined by the thickness, and if it is 10 μm or more, the support layer has a uniform and defect-free surface. In particular, since the polyolefin resin is melted, extruded by a laminator, and then cooled and set, the resin does not penetrate into the base paper or the ink receiving layer, so that it has little influence on the suitability for ink jet recording and is preferable.

The transportability in the ink jet recording apparatus is as follows.
It is necessary to control the glossiness of the outermost surface on the support layer side within a specific range, and the glossiness can be adjusted by the following method. For example, a method of adding a pigment to a composition containing a non-aqueous resin as a main component, a method of forming the outermost surface by bonding or bonding a base paper or a matted film, a composition containing a non-aqueous resin as a main component After providing the support layer, a method of applying an aqueous coating solution containing a pigment and a binder as main components, and a method of laminating a non-aqueous resin, by roughening the surface of a cooling roll, etc. Glossiness can be changed. By setting the glossiness of the support layer to 70% or less by such a method, good transportability can be obtained regardless of the surface state of the ink receiving layer.

In a mode in which the glossiness of the support layer is adjusted by adding a pigment to a non-aqueous resin or applying an aqueous coating liquid, the pigment to be added and the pigment applied to the aqueous coating liquid are There is no particular limitation, for example, specifically, carbonates, oxides, hydroxides, sulfates and the like of aluminum, zinc, magnesium, barium, titanium and the like, and natural silica, synthetic silica, clay, zeolite, kaolin And one or more organic pigments including copolymers such as starch, styrene resin, melamine resin, acrylic resin, urea resin, etc., and inorganic pigments including clays such as calcined kaolin.

The ink receiving layer referred to in the present invention refers to properties such as absorbency, image reproducibility and color saturation of dye inks and pigment inks used in commercially available ink jet printers, ink jet plotters and ink jet proofers. And a composition mainly composed of a pigment and a binder provided for the purpose corresponding to the above.

In the present invention, when an ink-receiving layer is provided, the amount of the ink-receiving layer is not particularly limited. The color and sharpness are low, and the ink is diffused in the direction of the surface of the base paper, resulting in deterioration of the dot shape called feathering, which is jagged like a bird's wing, and an image of good quality cannot be obtained. In addition, if the coating amount is too large, the drying load in the drying step after coating or impregnation increases, and not only the productivity decreases due to the decrease in the coating or impregnation speed, but also the drying under high load,
Binder in the coating composition constituting the ink receiving layer,
It moves to the surface of the ink receiving layer together with the solvent to evaporate, and reduces the amount of voids on the surface. Range of coating設量is 1 to 30 g / m ^2, more preferably from 4~20g / m ^2.

The problem that occurs with the ink receiving layer having a large coating amount is that it is possible to provide a plurality of ink receiving layers in accordance with the required quality. was affected the ability of concentration and drying process of the coated composition, preferably 1 to 30 g / m ^2, more preferably from 4~20g / m ^2.

Also, as for the ink jet recording paper having gloss, the coating amount may be set in accordance with the required quality, similarly to the above-described ink receiving layer. The glossy inkjet recording paper referred to in the present invention is a material obtained by providing an ink receiving layer on a base paper, calendering or casting with a super calender, soft calender, TG calender or the like, and colloidal silica or alumina sol on the outermost layer. After applying the colloidal particles or calendering these, applying a cast treatment, preliminarily applying an ink receiving layer on a film or process paper, and bonding it to the base paper or a base material provided with a coating layer on the base paper, It refers to a base paper base material with a glossy surface layer, such as a film or process paper removed.

In particular, according to the present invention, the surface of the ink receiving layer coated on the base paper has a surface defined by JIS P8142.
It is preferable because it is effective for inkjet recording paper having a mirror gloss of 5 degrees of 40% or more. Cockling is a phenomenon in which a base paper provided with an ink receiving layer expands and contracts due to printed ink, so that the recording paper is distorted and the surface of a printed portion is wavy. Therefore, as the gloss value of the surface of the ink receiving layer is higher, the reflected light is scattered by the undulation of the surface and becomes more conspicuous. Therefore, the present inventors have studied the cockling and the gloss value of the surface of the ink receiving layer, and have confirmed that cockling becomes more conspicuous when the gloss value of the receiving layer is 40% or more.

When the ink jet recording paper of the present invention is obtained, either the ink receiving layer or the support layer may be applied on the base paper first, but after the ink receiving layer is applied, the non-aqueous resin is applied. It is preferable to set up a composition as a main component. When the ink receiving layer is applied after setting the composition on the base paper, air existing in the gaps of the base paper when the coating liquid of the coating composition of the ink receiving layer is applied to the base paper. The ink cannot be removed from the support layer side, and air bubbles emerge on the coating surface.Therefore, air bubble marks are generated on the surface of the obtained ink receiving layer, which not only impairs the quality of the ink jet recording paper, but also causes the ink jet recording. May also affect properties.

The base paper referred to in the present invention is composed mainly of wood pulp and pigment. For wood pulp, LB
Chemical pulp such as KP, NBKP, GP, PGW, RM
Mechanical pulp such as P, TMP, CTMP, CMP, and CGP; waste paper pulp such as DIP; and non-wood pulp such as kenaf, bacas, bamboo, and cotton can also be used. Pigments, binders, sizing agents, fixing agents, retention agents, cationizing agents, and various additives such as paper strength enhancers are mixed using at least one of them, and the fourdrinier, round net, and twin wire paper machines are used. The base paper can be produced by various devices such as the above, and it can be made into an acidic, neutral or alkaline paper. Further, an ink receiving layer may be provided on the base paper as it is, or a multi-layer ink receiving layer in which a size press using starch, polyvinyl alcohol or the like or an ink receiving layer is provided after an anchor coat layer is provided.

Further, the base paper may be subjected to on-machine processing by a calender comprising a metal roll and a synthetic resin roll. At that time, off-machine processing may be performed, and after processing, flatness may be controlled by further performing calendar processing using a machine calendar, a super calendar, or the like.

One or more known white pigments can be used in the base paper and ink receiving layer used in the present invention.
For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic non-crystalline White inorganic pigments such as crystalline silica, colloidal silica, colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide, styrene-based plastic pigments,
Organic pigments such as acrylic plastic pigments, polyethylene, microcapsules, urea resins, melamine resins, and the like. Among the above, as the white pigment contained as the main component in the ink receiving layer, a porous inorganic pigment is preferable, and a porous synthetic amorphous silica, a porous magnesium carbonate, a porous alumina, and the like, and particularly, a pore volume Large porous synthetic amorphous silica is preferred.

Examples of the binder include polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, soybean protein, silyl-modified polyvinyl alcohol, etc .; styrene-butadiene Copolymer, methyl methacrylate
Conjugated diene copolymer latex such as butadiene copolymer; acrylic polymer latex such as acrylate and methacrylate polymer or copolymer, acrylic acid and methacrylic acid polymer or copolymer; ethylene Vinyl-based polymer latex such as vinyl acetate copolymer; or functional group-modified polymer latex with functional group-containing monomer such as carboxyl group of these various polymers; Thermosetting synthetic resin such as melamine resin and urea resin Aqueous adhesives such as; polymethyl methacrylate, polyurethane resin,
Synthetic resin-based adhesives such as unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and alkyd resin can be used, and one or more kinds are used.

Further, other additives include a pigment dispersant, a thickener, a flow improver, an antifoaming agent, a foam inhibitor, a release agent,
Foaming agents, penetrants, coloring dyes, coloring pigments, cationic dye fixing agents, fluorescent brighteners, ultraviolet absorbers, antioxidants, preservatives, anti-binders, waterproofing agents, wet paper strength agents, dry paper A force enhancer and the like can be appropriately compounded.

The method for coating and impregnating the base paper with the ink receiving layer according to the present invention includes various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters, short dwell coaters, curtain coaters, size presses, and the like. Can be used on-machine or off-machine. After coating or impregnation, finishing may be performed using a calendar such as a machine calendar, a TG calendar, a super calendar, or a soft calendar.

The ink used in the present invention includes the following colorants:
This is a recording liquid composed of a liquid medium and other additives.

Examples of the coloring agent include water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes, and food dyes.
Color pigments such as organic pigments such as carbon black and phthalocyanine and inorganic pigments such as iron oxide and zinc white are exemplified.

As a solvent for the ink, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-
C1-C4 alkyl alcohols such as ert-butyl alcohol and isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; acetone;
Ketones or ketone alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane;
Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol;
Alkylene glycols having 2 to 6 alkylene groups such as propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin, ethylene glycol methyl ether, diethylene glycol And lower alkyl ethers of polyhydric alcohols such as methyl (or ethyl) ether and triethylene glycol monomethyl ether. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol, and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether are preferable. Other additives include, for example, P
Examples include an H regulator, a metal sequestering agent, a fungicide, a viscosity modifier, a surface tension modifier, a wetting agent, a surfactant, and a rust inhibitor.

The ink-jet recording paper of the present invention is not limited to use as ink-jet recording paper.
Any type of recording paper using liquid ink at the time of recording may be used. For example, hot-melt substances,
Thermal transfer recording, in which a heat-meltable ink mainly composed of dyes and pigments is applied on a thin support such as resin film, high-density paper, synthetic paper, etc. Image receiving paper, ink-jet recording paper that heats and melts hot-melt ink to form fine droplets, and performs flight recording; ink-jet recording paper that uses ink in which an oil-soluble dye is dissolved in a solvent; photopolymerizable monomer and colorless or colored An image receiving paper corresponding to a photosensitive pressure-sensitive donor paper using a microcapsule containing a dye or pigment may be used.

A common feature of these recording papers is that the ink is in a liquid state at the time of recording. Liquid ink is cured,
By solidification or fixing, the ink permeates or spreads in the depth direction or horizontal direction of the ink receiving layer of the recording paper. The above-mentioned various recording papers require absorptivity according to each system, and the inkjet recording paper of the present invention may be used as the above-mentioned various recording papers. Further, the ink jet recording paper of the present invention may be used as the recording paper for heating and fixing the electrophotographic recording toner widely used in copiers and printers.

The ink jet recording paper of the present invention may be provided not only in the form of a cut sheet but also in the form of a roll. The support layer may be provided with an adhesive and used for sealing, labeling and tacking. is there.

[0048]

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.
Further, "parts" and "%" shown in Examples are parts by weight and% by weight unless otherwise specified.

<Preparation of base paper> Base papers A, B and C provided with an ink receiving layer and a support layer were obtained as follows.

(Base paper A) LB of 450 ml freeness CSF
To 100 parts of wood pulp consisting of 70 parts of KP and 30 parts of NBKP with a freeness of 450 ml CSF, light calcium carbonate /
The ratio of heavy calcium carbonate / talc is 30/35/35
After preparing 5 parts of a pigment, 0.1 part of a commercially available alkyl ketene dimer, 0.03 part of a commercially available cationic acrylamide, 1.0 part of a commercially available cationized starch and 0.5 part of a sulfuric acid band, using a fourdrinier paper machine. The paper was produced at a basis weight of 50 g / m ² , and the commercially available oxidized starch was dried with an ink-jet size press to a dry adhesion amount of 5 g / m ² to obtain base paper A. The thickness of the base paper was 60 μm.

(Base paper B) Base paper B was obtained in the same manner as base paper A, except that the basis weight of the base paper was 90 g / m ² . The thickness of this base paper was 115 μm.

(Base Paper C) Base paper C was obtained in the same manner as base paper A, except that the basis weight of the base paper was 165 g / m ² . The thickness of this base paper was 210 μm.

<Ink Receiving Layer> The ink receiving layer coated on the above-mentioned base paper was obtained as follows. A matte ink receiving layer having a low gloss was used as an ink receiving layer A, and an ink receiving layer having a glossy surface was used as an ink receiving layer B.

(Ink Receiving Layer A) The coating composition of the ink receiving layer A is a synthetic amorphous silica (fine seal X37).
B: 100 parts of Tokuyama Soda Co., Ltd., 30 parts of polyvinyl alcohol (PVA117: Kuraray Co., Ltd.), and 20 parts of cationic dye fixing agent (Sumireze Resin 1001: Sumitomo Chemical Co., Ltd.), solid content concentration Adjusted to 13%. Next, the composition was coated on a base paper using an air knife coater so as to have a dry coating amount of 9 g / m ^2, and this was subjected to a super calender treatment to obtain an ink receiving layer A.
I got

(Ink Receiving Layer B) The ink receiving layer B is composed of two layers. The following ink receiving layer was further laminated on the ink receiving layer A side of the ink receiving layer A in order to impart gloss. The coating composition of the ink receiving layer is colloidal silica (Snowtex XL: manufactured by Nissan Chemical Co., Ltd.)
00 parts, modified acrylic emulsion (Movinyl 802)
0: 15 parts of Hoechst Synthetic Co., Ltd.) and 10 parts of casein (New Zealand) dissolved in alkali to obtain a solid content concentration of 20%. The coating composition was dried on the ink receiving layer A using an air knife coater to a dry coating amount of 6 g / m ^2.
After coating, ink-receiving layer B was obtained by pressure contact with a heated mirror-finished roll and casting. The JIS when the ink receiving layer B is applied to the base papers A and B
The 75 degree glossiness of the ink receiving layer surface according to P8142 was 68 and 49%, respectively.

<Support Layers> On the opposite side of the ink receiving layer via the base paper, the following 10 types of support layers A, B,
C, D, E, F, G, H, I, and J were provided.

(Support Layer A) The base paper surface is subjected to corona discharge treatment, low-density polyethylene is provided to a thickness of 15 μm by using a melt extrusion die, and is pressed against a cooling roll having a rough surface to cool the support. Layer A was obtained.

(Support Layer B) The base paper surface is subjected to corona discharge treatment, low-density polyethylene is provided using a melt extrusion die so as to have a thickness of 15 μm, and the surface is pressed against a mirror-finished cooling roll to cool the support layer. B was obtained.

(Support Layer C) The surface of the base paper is subjected to corona discharge treatment, low-density polyethylene is provided to a thickness of 35 μm using a melt extrusion die, and is pressed against a cooling roll having a rough surface to cool the support. Layer C was obtained.

(Support Layer D) The surface of the base paper was subjected to corona discharge treatment, polyethylene was provided to a thickness of 35 μm using a melt extrusion die, and the surface was pressed against a cooling roll having a slightly rough surface to cool the support layer. D was obtained.

(Support layer E) Commercially available secondary kaolin 50
Parts and 50 parts of commercially available heavy calcium carbonate, 10 parts of commercially available styrene-butadiene latex, 5 parts of commercially available oxidized starch
Part was adjusted to a solid content concentration of 50%, and the coating composition obtained was coated and dried using an air knife coater to a dry coating amount of 15 g / m ² , subjected to supercalender treatment, and subjected to a support layer. E was obtained.

(Support layer F) Two support layers were provided on the base paper. A support layer B was set on the base paper, and then a corona discharge treatment was performed on the surface of the layer B, and a support layer E was applied on the surface to obtain a support layer F composed of two layers.

(Support Layer G) Two support layers were provided on the base paper. The support layer E was applied on the base paper, and then the surface of the layer E was subjected to a corona discharge treatment, and the support layer A was provided on the surface to obtain a support layer G composed of two layers.

(Support Layer H) Two support layers were provided on the base paper. When the support layer B is set up, the opposite side of the commercially available high-quality paper having a basis weight of 52.3 g / m ² and the base paper provided with the ink receiving layer is attached to the support layer B via the layer B, and the two layers are laminated. The resulting support layer H was obtained. When viewed from the ink jet recording surface side, the ink jet recording paper comprising the layer H has an ink receiving layer-base paper-polyethylene layer (support layer B)-
It is a configuration of high quality paper.

(Support layer I) Commercially available first-grade kaolin 10
0 parts, commercially available styrene-butadiene latex 10
And a coating composition obtained by adjusting 5 parts of a commercially available oxidized starch at a solid content concentration of 50% using an air knife coater so as to have a dry coating amount of 15 g / m ² and drying. A calendar process was performed to obtain a support layer I.

(Support Layer J) Two support layers were provided on the base paper. A support layer B was set on the base paper, and then a corona discharge treatment was performed on the surface of the layer B, and a support layer I was applied on the surface to obtain a support layer J composed of two layers.

Examples 1 to 10 and Comparative Examples 1 to 5 As shown in Table 1, Examples 1 to 10 and Combinations of base papers A to C, ink receiving layers A and B, and support layers A to J Inkjet recording papers of Comparative Examples 1 to 6 were obtained.

Table 1 shows the evaluation results of Examples 1 to 10 and Comparative Examples 1 to 5. The cockling and transportability shown in Table 1 were evaluated by the following methods.

<Evaluation of Cockling> A commercially available ink jet printer (MJ830C: manufactured by Epson Corporation)
Using a 1 in the center of the sample cut to A4 size
Solid printing was performed with black ink in a size of 5 cm square, and the degree of undulation on the printing surface during and after printing was visually evaluated, and judged based on the following criteria. There are no problematic levels of A and B. In C or D, cockling occurs, causing head rubbing, which causes a problem in that print quality is degraded and printing failure due to head clogging occurs. A: No cockling occurs. B: Cockling is slightly visually recognized at the boundary between the solid printing portion and the non-printing portion. C: Cockling was visually recognized in the entire printing portion, and the head was partially rubbed. D: The cock ring is visually recognized in a greatly expanded state, and the head rubs frequently.

<Evaluation of Transportability> Using the inkjet printer used for cockling evaluation, 20 sheets of A4 size inkjet recording paper were set as one set, and the transportability at the end of the five sets was evaluated according to the following criteria. The evaluation was performed by counting the number of untransports and the number of double feeds and calculating the number of occurrences. A and B are practically acceptable levels. A: Number of occurrences is zero B: Number of occurrences is 5 or less C: Number of occurrences is 6 to 10 D: Number of occurrences is 11 or more

<Gloss> The gloss of the ink receiving layer surface and the support layer surface was measured using a commercially available gloss meter (digital gloss meter GM-260D type: manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS P8142. , 75 degree specular gloss was measured.

[0072]

[Table 1]

As is clear from Table 1, at least one of the support layers is composed of a composition mainly composed of a non-aqueous resin, and the thickness of the layer is based on the total thickness of the base paper and the ink receiving layer. In Examples 1 to 8 which are not less than 20%,
Good cockling and transportability after printing. In Examples 9 and 10, since the glossiness of the surface of the support layer exceeds 70%, the transportability is reduced. In Comparative Example 1, a composition mainly composed of a non-aqueous resin was provided in the support layer. However, since the thickness of the layer was less than 20% of the total thickness of the base paper and the ink receiving layer, the thickness of the cockling was reduced. Deterioration occurred. In Comparative Examples 2 and 3 in which the thickness of the base paper was 200 μm or more, the transportability was reduced. In Comparative Examples 4 and 5, in which the non-aqueous resin was not applied to the support layer, cockling deteriorated.

[0074]

According to the present invention, at least one composition containing a non-aqueous resin as a main component is provided as a support layer on the opposite side of the ink receiving layer side via the base paper, and the thickness of the support layer is adjusted to By setting the thickness of the base paper and the ink receiving layer to 20% or more based on the total thickness, the waving phenomenon (cockling) of the printing portion surface during and after printing caused by printing is avoided, and the thickness of the base paper is further reduced. 30 or more, 200μ
m or less, the outermost surface on the support layer side has a glossiness of 70% or less, and the surface of the ink receiving layer has a glossiness of 40% or more. Can be provided.

Claims (4)

[Claims] 1. An ink jet recording sheet comprising at least one ink receiving layer on a base paper and at least one support layer on the opposite side of the ink receiving layer via the base paper. At least one layer is composed of a composition containing a non-aqueous resin as a main component, and 20% of the total thickness of the base paper and the ink receiving layer.
% Ink-jet recording paper, characterized in that it is provided with a thickness of at least 100%. 2. The ink jet recording paper according to claim 1, wherein the base paper has a thickness of 30 μm or more and 200 μm or less. 3. The outermost surface of the support layer is JIS P81.
3. The ink jet recording paper according to claim 1, wherein the 75-degree specular glossiness specified in 42 is 70% or less. 4. The method according to claim 1, wherein the surface of the ink receiving layer applied on the base paper has a surface gloss of 75% or more specified by JIS P8142 of 40% or more.
4. The ink jet recording paper according to any one of claims 1 to 3.