JPH08164665A - Ink-jet recording sheet - Google Patents

Abstract

PURPOSE: To secure good ink fixing and prevent ink from bleeding especially in a high humidity atmosphere by placing an ink receiving layer of a composition containing a specified ionene resin at least on one side of a support. CONSTITUTION: An ink receiving layer of the composition of ionene resin expressed by a formula I (Ra , shows formula II, etc., n and m are integers indicating a degree of polymerization, m=2-20, n=1-40) is laminated at least on one side of a support to make an ink-jet recording use sheet. A composition for coating the ink receiving layer is composed mainly of an inorganic pigment and a binder resin, and the ionene resin of the formula I is used as the binder resin or can be used as an additive other than the binder resin. The inorganic pigment has a specific surface area by BET of preferably 100m<2> /g or greater, more preferably 100-700m<2> /g. By using such inorganic pigment, printing density and ink absorption can be increased.

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, and more specifically, it ensures good ink fixability and allows ink bleeding and image formation over time, especially under high humidity conditions. The present invention relates to an inkjet recording sheet that prevents color deterioration.

[0002]

2. Description of the Related Art Inkjet recording systems use various types of operating principles typified by a deflection system, a cavity system, a thermojet system, a bubble jet system, a thermal inkjet system, a slit jet system, and a spark jet system. Droplets are ejected and attached to an inkjet recording sheet such as paper,
It records images, characters, etc., but it has high speed, low noise, easy multicoloring, and great flexibility in recording patterns.
It has advantages such as no need for development-fixing, and is rapidly spreading in various applications as a recording device for various figures including Kanji and color images. Furthermore, an image formed by an inkjet method using a multicolor ink containing dyes such as yellow, magenta, cyan and black is
It is possible to obtain a recorded image comparable to that of multicolor printing by the plate-making method or printing by the color photographic method. Further, in applications requiring a small number of copies, it is cheaper than the development by silver halide photography and is therefore being widely applied to the field of full-color image recording.

As an ink jet recording sheet used in this ink jet recording system, an ink jet recording apparatus, a dye structure and an ink can be used so that general paper such as high quality paper or coated paper used for ordinary printing or writing can be used. Focus has been placed on fields such as composition. However, as the performance of the inkjet recording apparatus is improved and the applications thereof are expanded, such as speeding up / definition or full-colorization, more advanced characteristics are required for the inkjet recording sheet. That is, as the ink jet recording sheet, the density of print dots is high, the color tone is bright and vivid, the absorption of ink is fast, the ink does not flow out or bleed even when the print dots overlap, The lateral diffusion does not become larger than necessary, the ink dot shape is close to a perfect circle,
In addition, it was necessary to satisfy various requirements such as smooth surroundings without blurring, high whiteness, and high contrast with ink dots.

Conventionally, in order to satisfy these conditions,
It has been proposed to coat various kinds of inorganic pigments on the surface of paper together with a binder resin, if necessary, or to fill the inside.
For example, use of synthetic amorphous silica or a salt thereof, or a mixture thereof as an inorganic pigment (JP-A-57-157).
No. 786), and the inclusion of a porous cationic hydrated aluminum oxide (Japanese Patent Laid-Open No. 232990/1985).
JP-A-60-204390 and JP-A-2-1988.
A recording sheet containing a synthetic amorphous silica having a large specific surface area by BET or a cationic hydrated aluminum oxide which is a cationic colloidal particle as described in JP-A-89, etc. has a high printing density It has the advantages of excellent absorption and color development. In order to improve the ink absorption by such an ink receiving layer, and to obtain a print dot having a higher print dot density and ink bleeding,
For example, JP-A-55-51583 and JP-A-56-15
No. 7, it is proposed to add non-colloidal silica powder. Further, for example, in JP-A-55-144172, etc., attention is paid to the fact that the color and sharpness are the distribution state of the dye in the ink in the ink receiving layer, and a specific agent that adsorbs the dye component is used. Suggestions have also been made.

However, according to the invention described above, in a relatively good environment, an ink does not seep out and an image excellent in color and sharpness can be obtained. It was difficult to obtain the same effect when the environment changes. Particularly, when the ink for ink jet recording is water-soluble, when the ink for ink jet recording is stored under high humidity conditions or after printing, the dye in the ink is dissolved by the humidity to cause ink bleeding phenomenon. . There is also a problem that the dye changes with time and the printed characters, images, etc. are discolored. The occurrence of the above-mentioned ink bleeding means that the dot diameter is enlarged, which reduces the sharpness and chromaticity of the image, thus deteriorating the image reproducibility.

When such a problem occurs, the value as an ink jet recording sheet is impaired. The following method can be considered to avoid such a problem. That is, it is preferable that the ink does not diffuse in the surface direction of the ink receiving layer in order to improve the sharpness of the image, and that the dye in the ink stays on the extreme surface of the ink receiving layer in order to maintain the color. . From this, it is ideal that only the solvent component in the ink quickly penetrates into the recording sheet. On the other hand, in order to avoid discoloration of the dye over time, for example, a means for allowing the dye to penetrate into the recording sheet in order to protect the dye from external factors such as light and ozone. However, the ink bleeding and the color deterioration of the image with time as described above are contradictory characteristics, and there is a difficulty in improving both of them at the same time.

With the widespread use of ink jet recording apparatuses in recent years, the environment for printing by the ink jet recording method has become considerably different, and image reproducibility that is not affected by the environment is required, and further, it is spreading to the field of full color images. In the ink jet recording system, the requirement for storability is also increasing, and there is a need for an ink jet recording sheet that satisfies these requirements.

[0008]

In view of the above situation, an object of the present invention is to secure good ink fixability, suppress ink bleeding out especially under high humidity conditions, and to further improve image quality over time. Another object of the present invention is to obtain an ink jet recording sheet in which the above-mentioned color deterioration is prevented.

[0009]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to the above problems in an ink jet recording sheet, and as a result, formed an ink receiving layer with a coating composition containing a specific agent. It has been found that the ink fixability is improved, ink bleeding is prevented even under high humidity conditions, and color deterioration of the image can be suppressed.

That is, the present invention relates to an ink jet recording sheet having an ink receiving layer provided on at least one surface of a support, and an ionene resin represented by the following chemical formula 2 (general formula 1) in the ink receiving layer composition. An ink jet recording sheet comprising:

[0011]

Embedded image (In the formula, m and n are integers indicating the degree of polymerization, and m = 2 to 20 and n = 1 to 40, respectively.)

The ink jet recording sheet of the present invention will be described in detail below. The ink receiving layer in the present invention contains the compound represented by the above chemical formula 2 (general formula 1). Here, the compound is a so-called ionene resin containing a quaternized amine in the main chain. As an example of a method for synthesizing such a compound, first, a bifunctional living polymer is obtained by ring-opening cationic polymerization of tetrohydrofuran using a strong acid anhydride such as trifluoromethanesulfonic acid anhydride as an initiator. Then, the polymer is reacted with dimethylamine to obtain poly (tetrahydrofuran) [poly (tetramethylene oxide)] having dimethylamino groups at both ends. further,
The target quaternary salt compound is obtained by chain-extending a dihalide such as α, α′-dichloro-ρ-xylene and 1,2-dichloromethane in an equimolar amount to the dimethylamino groups at both ends by the Menhutkin reaction. 3 and 4). Here, the Menhutkin reaction is a condensation reaction between an alkyl halide and a tertiary amine. In the alkyl halide, the reactivity is improved in the order of I>Br> Cl, and the solvent is methyl alcohol> ethyl. The order of alcohol>acetone>benzene> hexane improves the reactivity.

Further, the above dimethylamine is replaced with 4,4'-
Dipyridine, 1,2-bis (4-pyridyl) ethane,
A pyridinium salt type target compound can be obtained by substituting dipyridines such as 1,2 bis (4-pyridyl) ethylene (Chemical Formulas 5, 6 and 7 below).

[0014]

Embedded image

[0015]

[Chemical 4]

[0016]

Embedded image

[0017]

[Chemical 6]

[0018]

[Chemical 7] However, in Chemical formulas 3 to 8, both m and n are integers indicating the degree of polymerization, and m = 2 to 20 and n = 1 to 40, respectively.
Is.

The degree of polymerization m of such a quaternary salt compound and the blending amount in the ink receiving layer are largely related to the viscosity of the coating composition of the ink receiving layer, and in production such as liquid preparation and coating amount control. It may be appropriately determined in consideration of the viscosity within a range that does not cause a problem, but the polymerization degree m is easy to handle, and the blending amount is a cationic colloid titration amount (cation charge) of the quaternary salt measured by a colloid titration method. Amount) E _D [meq./g] and the 4
The product P _D (quantity of cationic colloid drops per unit area of the inkjet recording sheet) with the content W _D [g / m ² ] of the graded salt in the ink receiving layer is 0.2 to 40 meq./m ² , and more preferably Is determined to be 0.7 to 20 meq./m ² . Here, if it is less than 0.2 meq./m ² , it tends to be difficult to secure the fixability of the ink, and it is difficult to avoid color deterioration of the image.
On the other hand, if it exceeds 40 meq./m ² , the absorption speed of the ink that permeates through the ink receiving layer is poor, so that the ink is diffused on the surface of the ink receiving layer and the sharpness is apt to decrease with the increase of the dot diameter.

Further, in order to obtain the same level of ink fixability, it is necessary to increase the compounding amount of the quaternary salt compound as the polymerization degree m thereof decreases. It is considered that this is because the both terminals of the quaternary salt compound are tertiaryized, and thus the cationicity decreases as the polymerization degree m decreases. However, if the blending amount is increased too much, the physical structure of the quaternary salt compound formed in the ink receiving layer may impede the ink permeability, resulting in an increase in the dot diameter. Therefore, including the above problem of viscosity, the degree of polymerization m of the quaternary salt compound is 2 to 20.
Is preferred.

The degree of polymerization n of tetrahydrofuran is 1
-40 is preferable, and 10-20 is more preferable.
Here, when n exceeds 40, the water solubility of the quaternary salt compound is poor, and undissolved portions are generated in the coating composition of the ink receiving layer, which is not preferable.

The coating composition for the ink receiving layer of the ink jet recording sheet according to the present invention mainly comprises an inorganic pigment and a binder resin, and the above quaternary salt compound is used as a binder resin or a binder resin. It can be used as another additive. Here, the inorganic pigment is a specific surface area by BET is 100 m ² / g or more, further preferably inorganic pigments 100~700m ² / g.
By using an inorganic pigment having such a specific surface area,
High print density and excellent ink absorbency can be exhibited. If the BET specific surface area of the inorganic pigment is less than 100 m ² / g, sufficient printing density and ink absorbency cannot be obtained.

As such an inorganic pigment, one or more conventionally known white pigments may be used alone or in combination, and examples thereof include light calcium carbonate, heavy calcium carbonate, kaolin, talc and calcium sulfate. , Barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate,
Satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudo-boehmite,
Aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide and the like can be mentioned.

Among the above-mentioned inorganic pigments, synthetic amorphous silica is particularly preferably used for the ink jet recording sheet of the present invention because of its print density, ink absorbency,
It is possible to obtain an ink jet recording sheet having excellent printed image sharpness. Examples of such synthetic amorphous silica include those disclosed in JP-A-57-157786 and 61.
-141584 gazette, the same 61-230979 gazette,
As described in Japanese Patent Laid-Open No. 62-292476,
It is a microporous, amorphous fine particle in which a three-dimensional structure of SiO ₂ is formed by gelation of silicic acid, and a typical physical property value range thereof is an average particle diameter of about 10 nm to 20 μm and a Hunter whiteness of 90. As described above, the pore diameter is about 10 to 2000 angstrom.

As such synthetic amorphous silica, commercially available products can be preferably used. For example, Mizukasil P-
526, Mizukasil P-801, Mizukasil NP-8,
Mizukasil P-802, Mizukasil P-802Y, Mizukasil C-212, Mizukasil P-73, Mizukasil P
-78A, Mizukasil P-78F, Mizukasil P-8
7, Mizukasil P-705, Mizukasil P-707, Mizukasil P-707D, Mizukasil P-709, Mizukasil C-402, Mizukasil C-484 (manufactured by Mizusawa Chemical Co., Ltd.), Tokusil U, Tokusil UR, Tokusil G
U, Tokuseal AL-1, Tokuseal GU-N, Tokuseal N, Tokuseal NR, Tokuseal PR, Sorex, Fineseal E-50, Fineseal T-3
2, fine seal X-37, fine seal X-7
0, Fineseal RX-70 Fineseal A, Fineseal B (above, manufactured by Tokuyama Soda), Carplex FPS-101, Carplex CS-7, Carplex 80, Carplex XR, Carplex 67
(Above, manufactured by Shionogi Pharmaceutical Co., Ltd.), Syloid 63, Syloid 65, Syroid 66, Syroid 77, Syroid 7
4, Syloid 79, Syloid 404, Syloid 6
20, Thyroid 800, Thyroid 150, Thyroid 244, Thyroid 266 (above, manufactured by Fuji Silysia Chemical Ltd.) and the like.

Cationic colloid particles may be added to the ink receiving layer in the present invention in combination with the above-mentioned inorganic pigment. The term "cationic colloidal particles" as used herein means particles that are suspended and dispersed in water to form a colloidal shape, and the particles have positively charged surfaces, and examples thereof include alumina sol such as boehmite and pseudo-boehmite, and colloidal alumina. Alternatively, as disclosed in Japanese Examined Patent Publication No. 47-26959, particles having colloidal silica particles whose surfaces are coated with alumina may be used.

In the ink receiving layer of the ink jet recording sheet of the present invention, the above quaternary salt compound can be used as the binder resin for the inorganic pigment, but other binder resins can be used if necessary.
As the binder resin that can be preferably used, for example, polyvinyl alcohol, silanol-modified polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, carboxymethyl cellulose, cellulose derivatives such as hydroxyethyl cellulose, casein, gelatin,
Soybean protein, silyl-modified polyvinyl alcohol, etc .; Conjugated diene copolymer latex such as maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, etc .; Acrylic acid ester and methacrylic acid ester polymer or copolymer Acrylic polymer latexes such as polymers, polymers or copolymers of acrylic acid and methacrylic acid; vinyl polymer latexes such as ethylene vinyl acetate copolymers; or functional groups such as carboxyl groups of these various polymers Functional group-modified polymer latex with contained monomers; Thermosetting synthetic resin-based water-based adhesives such as melamine resin and urea resin; Polymethylmethacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-
One or more synthetic resin adhesives such as vinyl acetate copolymer, polyvinyl butyral, and alkyd resin may be used alone or in combination. In addition, known natural
Alternatively, the use of the synthetic resin binders alone or in combination is not particularly limited.

The amount of the binder resin added is preferably 3 to 70 parts by weight, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the inorganic pigment. If the strength is insufficient, and if it exceeds 70 parts by weight, the ink absorption capacity is insufficient depending on the type of the inkjet recording apparatus, and the ink overflows, which is not preferable.

Further, as other additives, pigment dispersants, thickeners, fluidity improvers, defoamers, defoamers, mold release agents,
Foaming agents, penetrants, coloring dyes, coloring pigments, optical brighteners, UV absorbers, preservatives, anti-bacterial agents, water resistance agents, wet paper strength agents, dry paper strength agents, antioxidants, etc. It can also be added.

As the support in the present invention, LBK is used.
Chemical pulp such as P, NBKP, GP, PGW, RMP,
Mechanical pulp such as TMP, CTMP, CMP, CGP, D
Using at least one kind of various additives such as binders and sizing agents, fixing agents, yield improving agents, cationizing agents, paper strengthening agents, etc., based on wood pulp such as IP and other wood pulp and conventionally known pigments as main components. And mix, fourdrinier paper machine, cylinder paper machine,
Base paper manufactured by various devices such as twin wire paper machine,
Further, the base paper includes a base paper in which a size press with starch, polyvinyl alcohol or the like or an anchor coat layer is provided, and coated paper such as art paper, coat paper or cast coat paper in which a coat layer is provided thereon. Such a base paper and a coated paper may be provided with the coating layer according to the present invention as they are, and a machine calendar, TG may be used for the purpose of controlling the flatness.
A calendar device such as a calendar or a soft calendar may be used. The basis weight of the support is usually 40 to
It is 300 g / m ² , but is not particularly limited.

As a method of providing the ink receiving layer on the support in the present invention, a hydrophilic organic solvent such as water or alcohol, or a mixed solvent thereof is used, for example, a conventionally known air knife coater, curtain coater, Die coater, blade coater, gate roll coater,
Bar coater, rod coater, roll coater, bill blade coater, short dwell blade coater,
It can be coated on the support by various devices such as a size press. Further, after coating the ink receiving layer, a smoothing treatment can be carried out using a calendar device such as a machine calendar, a TG calendar, a super calendar and a soft calendar.

The coating amount of the ink receiving layer in the present invention is not particularly limited, but is preferably 1 to 30 g / m ² . When the coating amount is less than 1 g / m ^2, it is not preferable because sufficient printing density and ink absorbency cannot be obtained, and when the coating amount exceeds 30 g / m ² , curling property of the recording sheet is deteriorated, which is not preferable. . In addition, the ink receiving layer can be applied with a certain coating amount divided into several times, and in the case of imparting gloss, the gloss is improved as compared with applying the coating amount at once. .

By providing a gloss-developing layer on the ink receiving layer by a cast coating method, it is possible to obtain a gloss feeling comparable to that of a commercially available cast coated paper.

A back coat layer may be provided on the opposite surface of the ink receiving layer sandwiching the support in order to impart curl aptitude, and a pigment in that case is a tabular pigment. Or hydrolyzed halloysite is preferable, and even if no back coat is provided, curl can be forced by injecting water vapor with a humidifier such as Fludex.

The ink referred to in the present invention is a recording liquid containing the following dyes, solvents and other additives, and the dyes have good coloring properties, vividness, stability, etc., for example,
C. I. Direct Yellow 12, C.I. I.
Direct Yellow 24, C.I. I. Direc
t Yellow 26, C.I. I. Direct Ye
low 44, C.I. I. Direct Yellow
86, C.I. I. Direct Yellow 98,
C. I. Direct Yellow 100, C.I.
I. Direct Yellow 142, C.I. I. D
direct red 1, C.I. I. Direct re
d 4, C.I. I. Direct red17, C.I. I.
Direct red 28, C.I. I. Direct
red83, C.I. I. Direct Orange 3
4, C.I. I. Direct Orange 39, C.I.
I. Direct Orange 44, C.I. I. Di
rect Orange 46, C.I. I. Direct
Orange 60, C.I. I. Direct Vio
let 47, C.I. I. Direct Violet
48, C.I. I. Direct Blue 6, C.I. I.
Direct Blue 22, C.I. I. Direct
Blue 25, C.I. I. DirectBlue 7
1, C.I. I. Direct Blue 86, C.I. I.
Direct Blue 90, C.I. I. Direct
Blue 106, C.I. I. Direct Blue
199, C.I. I. Direct Black 17,
C. I. Direct Black 19, C.I. I. D
direct Black 32, C.I. I. Direct
Black 51, C.I. I. Direct Black
62, C.I. I. Direct Black 71,
C. I. Direct Black 108, C.I. I.
Direct Black 146, C.I. I. Dire
direct dyes such as ct Black 154, C.I. I. Ac
id Yellow 11, C.I. I. Acid Yel
low 17, C.I. I. Acid Yellow 2
3, C.I. I. Acid Yellow 25, C.I. I.
Acid Yellow 29, C.I. I. Acid Ye
low 42, C.I. I. Acid Yellow 4
9, C.I. I. Acid Yellow 61, C.I. I.
Acid Yellow 71, C.I. I. Acid r
ed 1, C.I. I. Acid red 6, C.I. I. A
cid red 8, C.I. I. Acid red32,
C. I. Acid red 37, C.I. I. Acid
red 51, C.I. I. Acid red 52, C.I.
I. Acid red 80, C.I. I. Acid re
d 85, C.I. I. Acid red 87, C.I. I.
Acidred 92, C.I. I. Acid red 9
4, C.I. I. Acid red 115, C.I. I. Aci
d red 180, C.I. I. Acid red 25
6, C.I. I. Acid red 317, C.I. I. Ac
id red 315, C.I. I. Acid Orange
e 7, C.I. I. Acid Orange 19, C.I.
I. Acid Violet 49, C.I. I. Acid
Blue 9, C.I. I. Acid Blue 22,
C. I. Acid Blue 40, C.I. I. Acid
Blue 59, C.I. I. Acid Blue 9
3, C.I. I. Acid Blue 102, C.I. I. A
cid Blue 104, C.I. I. Acid Blu
e 113, C.I. I. Acid Blue 117,
C. I. Acid Blue 120, C.I. I. Aci
d Blue 167, C.I. I. Acid Blue
229, C.I. I. Acid Blue 234, C.I.
I. Acid Blue 254, C.I. I. Acid
Black 2, C.I. I. Acid Black 7,
C. I. Acid Black 24, C.I. I. Aci
d Black 26, C.I. I. Acid Black
31, C.I. I. Acid Black 52, C.I.
I. Acid Black 63, C.I. I. Acid
Black 112, C.I. I. Acid Black
Acid dyes such as 118 and other water-soluble dyes such as basic dyes, reactive dyes or food dyes can be used.

As the ink solvent, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol and isobutyl are used. Alkyl alcohols having 1 to 4 carbon atoms such as alcohols; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol, polypropylene glycol, etc. Polyalkylene glycols; ethylene glycol, propylene glycol, butylene glycol,
Alkylene glycols having 2 to 6 alkylene groups such as triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol; glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether , Lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether, and the like.

Among the above 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 particularly preferable.

Other additives added to the ink include, for example, pH adjusters, sequestering agents, antioxidants,
Examples thereof include antifungal agents, viscosity modifiers, surface tension modifiers, wetting agents, surfactants, and rust preventives.

[0039]

The bleeding of the ink is a phenomenon in which the ink spreads on the printing surface, and in order to prevent this, it is necessary to permeate in the depth direction of the printing surface. Therefore, the ink bleeding can be prevented by applying an ink receiving layer having a large surface area to promote the penetration of the ink. However, since the dye in the ink penetrates in the depth direction at the same time,
Deterioration of color characteristics occurs as the print density decreases. This dye dissolves in the solvent component, and since the solvent component exhibits anionicity, the dye having a cationic group is contained in the ink-receiving layer to cause the dye to stay on the extreme surface of the ink-receiving layer, thereby printing It is possible to prevent the density from decreasing, but at the same time, the permeation of the solvent is suppressed, so that the ink bleeds again.

Although the bleeding of ink and the print density are contradictory characteristics, the print density shows the reflectance of visible light, and the reflectance is not only on the surface of the ink receiving layer but also on the surface of the ink receiving layer where the visible light is visible. It is not possible to ignore the influence of the internal reflection that has entered the surface of the ink-receiving layer and then is emitted again from the surface of the ink receiving layer. This means that the dye existing in the ink receiving layer is involved, and it is suggested that the printing density is improved even if the dye is retained in the ink receiving layer. Therefore, the contradictory characteristics are that the ink permeates quickly on the surface of the ink receiving layer, and if the ink stays in the ink receiving layer, the ink can be exuded and the print density can be improved.

From this, it can be considered to increase the surface area of the ink receiving layer and to use the agent having a cation group, but considering the exudation due to the dissolution of the dye under the high humidity condition which is the object of the present invention. The latter choice is suitable.
This is because the former is physical adsorption, whereas the latter is an electrical or chemical bond, and the latter has a much lower dissolution of the dye by moisture under high humidity conditions. Is.

It is also an object of the present invention to avoid the problem of color deterioration of printed images over time. This is considered to be due to the fact that the dye changed its absorption spectrum due to some influence by external factors such as light and ozone. However, the ink receiving layer containing the quaternary salt compound according to the present invention prevents this color deterioration. Although the exact reason for this action is not clear, the absorption spectrum of the dye is stabilized by binding of the quaternary salt compound of the present invention to the dye, or the quaternary salt compound of the present invention having film-forming property is obtained. It is considered that the influence of light and ozone was prevented by covering the dye.

[0043]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.
Further, “parts” and “%” shown in the examples represent parts by weight and% by weight, unless otherwise specified.

[Synthesis of α, ω-bis (dimethylamino) polytetramethylene oxide] 500 ml equipped with a vacuum stirrer, a nitrogen gas inlet pipe and an outlet pipe.
30 g of tetrahydrofuran and 25 g of dichloromethane were placed in the three-necked flask described in (1), and after substituting with nitrogen gas, the temperature was kept at 0 ° C. in an ice water bath. Then, 2.5 g of trifluoromethanesulfonic anhydride was added to the three-necked flask and stirred. After the tetrahydrofuran solution in the flask became colorless, it was stirred at 5 ° C. for 20 minutes. Further, while maintaining the temperature at 5 ° C., 90 g of tetrahydrofuran was added and stirring was continued for 120 minutes. To this tetrahydrofuran solution, 50 ml of tetrahydrofuran in which 9 g of anhydrous dimethylamine was dissolved was gradually added and polymerized. After the reaction was completed, the liquid temperature was raised to room temperature and stirred for 20 minutes, and then 1
The mixture was transferred to a round bottom flask containing 50 ml of toluene, and dichloromethane, unreacted dimethylamine anhydride and tetrahydrofuran were removed using a rotary evaporator. Further, add 500 ml of toluene to the residue,
After treatment with a 25% aqueous sodium hydroxide solution, heating was carried out for 20 minutes to completely remove dimethylamine. After separating the aqueous solution with a separatory funnel, the organic phase was dried with magnesium sulfate powder. The average molecular weight of the α, ω-bis (dimethylamino) polytetramethylene oxide synthesized in this manner was 2,500.

[Condensation reaction of α, ω-bis (dimethylamino) polytetramethylene oxide and dihalide] 8 g of α, ω-bis (dimethylamino) polytetramethylene oxide obtained as described above was converted into α, α '. -Dichloro-ρ-xylene (Aldrich Chemical
Manufactured by K.K.) was added to 50 ml of a 2.5% tetrahydrofuran solution, and heating was continued while stirring with a magnetic stirrer until the viscosity was sufficiently reduced. Next, tetrahydrofuran was evaporated at room temperature to obtain a quaternary salt compound having the above-described structure (corresponding to quaternary salt compound A having the above-described structure). The average molecular weight of the quaternary salt compound is 12,900.
(M = 5, n = 32).

Example 1 The support was composed of light calcium carbonate / heavy calcium carbonate / talc based on 100 parts of wood pulp consisting of 80 parts of LBKP (freeness of 400 mlcsf) and 20 parts of NBKP (freeness of 480 mlcsf). 20 parts of pigment having a ratio of 10/10/10, 0.10 parts of commercial alkyl ketene dimer,
After preparing 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, papermaking was carried out with a Fourdrinier paper machine to obtain a support having a basis weight of 90 g / m ² .

The ink receiving layer was coated on the surface of the support.
The coating composition of the ink receiving layer has a BET specific surface area of 270 m ²
/ g of synthetic amorphous silica (Fineseal X-37B, manufactured by Tokuyama Soda) 100 parts, polyvinyl alcohol (PVA1
(17, manufactured by Kuraray Co., Ltd.) 30 parts and quaternary salt compound A (20 parts) were used to prepare a solution, which had a solid content concentration of 14%. This coating composition was dried with an air knife coater to give a dry coating amount of 8
The support was coated so as to be g / m ² and dried to obtain an ink jet recording sheet of Example 1.

Examples 2 to 8 All were prepared and carried out in the same manner as in Example 1 except that the quaternary salt compounds A to E corresponding to the above Chemical Formulas 3 to 7 were used as shown in Table 1 below. The inkjet recording sheets of Examples 2 to 8 were obtained.

Examples 9 to 11 Ink were prepared in the same manner as in Example 1 except that the coating composition of the ink receiving layer was changed to the compounding amount shown in Table 1 to obtain ink jet recording sheets of Examples 9 to 11. .

Comparative Example 1 Comparative Example 1 was prepared in the same manner as in Example 1 except that the quaternary salt compound was not added to the coating composition for the ink receiving layer.
To obtain an ink jet recording sheet.

Comparative Example 2 An ink jet recording sheet of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that the coating amount of the coating composition for the ink receiving layer was 10 g / m ² .

The evaluations of Examples 1 to 11 and Comparative Examples 1 and 2 were carried out by the following methods, and the results are summarized in Table 1.

<Dot Enlargement Rate> Each ink jet recording sheet sample was conditioned under the environment of 20 ° C. and 65% RH for 24 hours, and then the ink jet printer (M
J-700V2C, manufactured by EPSON), dots are printed with black ink, and an equivalent circle diameter defined by the following formula 1 is measured using an image analyzer. Then 40 ° C,
After leaving the ink jet recording sheet sample printed under the environment of 90% RH for 24 hours, calculate the equivalent circle diameter of the dot again by the following mathematical formula 1, and calculate the equivalent circle diameter before and after leaving it at 40 ° C. and 90% RH. The ratio D ₂ / D ₁ of (D ₁ and D ₂ ) was defined as the dot enlargement ratio.

[0054]

## EQU1 ## Di = {(4 / π) × A} ^1/2 where Di is the equivalent circle diameter, and i = 1 is 40 ° C., 90
The equivalent circle diameter before being left in% RH, i = 2 is the equivalent circle diameter after leaving the same. A is the measured area.

<Image color deterioration rate> Solid printing was performed with a black ink using an inkjet printer (MJ-700V2C, manufactured by EPSON), and the color difference between the colors before and after light irradiation for 30 hours was measured with a xenon fade meter. The color difference can be defined by the following formula 2 based on the result of measuring the color of the sample before and after the light irradiation according to L * a * b * (CIE1976). The larger the color difference, the more the color deterioration occurs. The measurement was performed using a standard light C, CR100 manufactured by Minolta. If the color difference is less than 1.0, it is almost impossible to visually recognize the color difference.

[0056]

[Equation 2] ΔE = {(ΔL *) ² + (Δa *) ² + (Δb *) ² } ^1/2 where ΔE is the color difference, ΔL * and Δa * and Δb * Is the difference between L * and a * and b * before and after light irradiation.

[0057]

[Table 1]

As is clear from the results shown in Table 1, Example 1
In Nos. 11 to 11, since the quaternary salt compound according to the present invention was contained in the ink receiving layer, redissolution of the dye due to the presence of water under high humidity conditions and color deterioration of the image after light irradiation were prevented. However, in Comparative Examples 1 and 2 which did not contain the quaternary salt compound according to the present invention, dot enlargement and image color deterioration were remarkable. In Comparative Example 2 in which the coating amount was increased,
Although the dot enlargement and the color deterioration of the image are reduced, it is understood that the effect is small as compared with Examples 1 to 11.

[0059]

As is apparent from the above, according to the present invention, good ink fixability is ensured, ink bleeding is prevented especially under high humidity conditions, and further, image formation over time is performed. It is possible to obtain an inkjet recording sheet in which color deterioration is prevented.

Claims (1)

[Claims] 1. An inkjet recording sheet having an ink receiving layer on at least one surface of a support, wherein the ink receiving layer composition contains an ionene resin represented by the following chemical formula 1 (general formula 1). An inkjet recording sheet characterized by: Embedded image (In the formula, m and n are integers indicating the degree of polymerization, and m = 2 to 20 and n = 1 to 40, respectively.)