JPH08164664A - Ink-jet recording sheet - Google Patents

Abstract

PURPOSE: To improve the yellowing resistance of a base surface by forming an ink receiving layer with a composition which is composed of inorganic pigment, etc., having a specified specific surface area in which cycloamylose is fixed in an area of a specified value of the specific surface area or larger. CONSTITUTION: An ink receiving layer composition is prepared which is composed mainly of an inorganic pigment with a specific surface area of 100m<2> /g or larger measured by BET in which cycloamylose is fixed in an area 20% or larger of the specific surface area and a binder resin. The composition is applied on a support and dried to make an ink-jet recording use sheet. Cycloamylose which can be used preferably is β-cycloamylose which has higher packaging efficiency for a coloring matter in comparison with α-and γ- cycloamylose and can prevent efficiently the coloring matter from fading. The inorganic pigment contained in the ink receiving layer has preferably the specific surface area by BET of 100m<2> /g or larger.

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 an aqueous ink, and more specifically, it has good yellowing resistance of the background of the ink jet recording sheet and is recorded. The present invention also relates to an ink jet recording sheet which is excellent in storability such as water resistance, ozone resistance and light resistance of images and characters.

[0002]

2. Description of the Related Art Ink-jet recording systems use a variety of operating principles typified by a deflection system, a cavity system, a thermo-jet system, a bubble-jet system, a thermal inkjet system, a slit-jet system, and a spark-jet system. Although droplets are ejected and deposited on an ink jet recording sheet such as paper to record images and characters, high speed, low noise, easy multicoloring, great flexibility in recording patterns, development -It has the advantage that it does not require fixing, and is rapidly spreading in various applications as a recording device for various figures including Kanji and color images. Further, an image formed by an inkjet method using a multicolor ink containing dyes such as yellow, magenta, cyan, and black has a color comparable to that of a multicolor printing by a plate making method or a printing by a color photographic method. It is possible to obtain no recorded image. Further, in applications where the number of copies to be made is small, it is cheaper than the development by silver salt 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 ordinary ink jet recording apparatus, a dye structure or 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. It has been focused on fields such as composition. However, as the performance of inkjet recording devices has improved and the applications have expanded, such as speeding up, high definition, and full-color printing,
Higher characteristics have also been required for inkjet recording sheets. 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, There are various requirements such as that the lateral diffusion does not become unnecessarily large, the shape of the ink dot is close to a perfect circle, the periphery is smooth and does not blur, the whiteness is high, and the contrast with the ink dot is large. I needed to be satisfied.

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, synthetic amorphous silica or a salt thereof as an inorganic pigment,
Alternatively, use of a mixture thereof (Japanese Patent Laid-Open No. 57-15 / 1982)
No. 7786) or containing a porous cationic hydrated aluminum oxide (JP-A-60-232990).
No. 60-204390 and Japanese Patent Laid-Open No. 2-19 are especially proposed.
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-8889, has a high printing density and a high ink density. It has advantages such as excellent absorption and color development.

However, in an ink jet recording sheet containing such an inorganic pigment, generally, the fading of the dye due to ozone, light, etc. easily progresses, and the fixability of the dye is poor, so that the ink jet recording sheet. Water adhered to the surface, and the dye exuded during long-term storage under high humidity conditions, which markedly impaired the quality of the inkjet recording sheet.

In view of the above problems, as a means for improving the fading of the dye due to ozone, light, etc., for example, as proposed in JP-A-57-87987,
Specific metal oxides such as phosphotungstic acid and phosphomolybdic acid, and specific metal chlorides such as chromic chloride are contained, and phenylsalicylic acid and the like such as proposed in JP-A-57-87988. Although it has been proposed to include an ultraviolet absorber having a specific structure, when these additives are used, there are disadvantages such as yellowing the background of the inkjet recording sheet and changing the hue of the dye. Not only does it cause ozone resistance,
There was still room to improve the effect of improving light resistance.

On the other hand, as means for preventing the adhesion of water and the bleeding of dyes during long-term storage under high humidity conditions, for example, Japanese Patent Laid-Open Nos. 61-125878 and 61-125878 have been proposed.
Although it has been proposed to include a cationic fixing agent having a specific structure as proposed in JP-A-58788 and 61-74880, when such a cationic fixing agent is used. However, the background of the ink jet recording sheet turns yellow, and the cationic fixing agent itself is inferior in stability to ozone and light, resulting in fading of the dye.

The above-mentioned yellowing of the background is remarkably generated, for example, when an ink jet recording sheet is put in a clear file for storage or an adhesive tape is attached to the surface of the ink receiving layer. The reason for this is not clear,
This is because the antioxidants contained in files such as polyethylene and polypropylene, adhesives for tapes, glues, rubbers, etc. are transferred to the inorganic pigments in the ink receiving layer and adsorbed and oxidized on the inkjet recording sheet. Presumed to be. Polyethylene, polypropylene, etc. often contain a large amount of an antioxidant having a phenol group in the molecule, such as butylhydroxytoluene, and when these phenolic antioxidants oxidize and take a quinone structure, they become yellow. It is well known that it changes.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the yellowing resistance of the background of an ink jet recording sheet over time, and to improve the water resistance of recorded images and characters.
An object is to obtain an ink jet recording sheet having excellent storage stability such as ozone resistance and light resistance.

[0010]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to the above problems in ink jet recording sheets, and as a result, have found that the dye contained in the ink is included in cycloamylose. . Furthermore, they have found that the dye encapsulated by cycloamylose is protected from ozone and light, and thus fading of the dye is suppressed.

Further, since it has been confirmed that the fading of the dye and the yellowing of the ink jet recording sheet in the ink jet recording sheet using the inorganic pigment are promoted by the solid acid points of the inorganic pigment, the wetting characteristic of the inorganic pigment is confirmed. It has been found that if solid acid points can be eliminated without impairing the properties, the fading of the dye and the yellowing of the background of the inkjet recording sheet are improved.

On the other hand, regarding the fixing property of the dye, it is necessary to immobilize the cycloamylose on the ink jet recording sheet because the dye exudes together with the cycloamylose only by including the dye with cycloamylose. , Based on the above results, by fixing cycloamylose to the surface of the inorganic pigment in the ink receiving layer, ozone, fading of the dye due to light, fixability of the dye and yellow color change of the background of the inkjet recording sheet at the same time. I found that it could be improved.

That is, the ink jet recording sheet of the present invention is an ink jet recording sheet in which an ink receiving layer is provided on a support, and the ink receiving layer composition is an inorganic material having a specific surface area of 100 m ² / g or more mainly by BET. An ink jet recording sheet, comprising a pigment and a binder resin, wherein the inorganic pigment has cycloamylose immobilized on 20% or more of its specific surface area.

Preferably, the cycloamylose is β-cycloamylose, which is an ink jet recording sheet.

Further, preferably, the cycloamylose is maltosyl-modified cycloamylose, which is an ink jet recording sheet.

More preferably, the cycloamylose is cation-modified cycloamylose, which is an ink jet recording sheet.

The ink jet recording sheet of the present invention will be described in detail below. In the present invention, cycloamylose is a non-reducing maltooligosaccharide in which 6 to 12 glucose molecules belonging to a cyclic oligosaccharide are cyclically linked by an α-1,4-glucoside bond, and is a bacillus (Bacil).
It is obtained by reacting cyclodextrin glucanotransferase, which is a cycloamylose-producing enzyme produced by a microorganism of the genus Lus).
The main products from starch are glucose 6, 7 and 8
Α-, β-, and γ-cycloamylose (other names: α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin) each having a molecular weight of 973, 1135, and 1297, and The inner diameter of the glucose ring is 5-6 angstroms, 7
-8 angstroms, 9-10 angstroms. Cycloamylose is composed of highly hydrophilic glucose units, but the inside of the glucose ring is hydrophobic with a high electron density due to the α-1,4 bond and the C—H group, so it fits the size of the glucose ring. An organic compound can be included.

In the present invention, cycloamylose which can be preferably used is β-cycloamylose,
As compared with α- and γ-cycloamylose, the inclusion efficiency of the dye is good, and fading of the dye can be efficiently prevented.
As described above, the inner diameter of cycloamylose is about 5 to 10 angstroms, and it is impossible to include the entire dye used in a general inkjet recording ink as a guest. The expression mechanism of the effect of improving the sex is not clear, but in the dye molecule,
For example, a phenyl group and a dialkylamino group added thereto, a nitro group, an auxiliary chromophore such as a halogen atom, N = N,
It is presumed that this is because a part of the chromophore such as C = N that is attacked by ozone or light is partially included.

The cycloamylose used in the present invention is
It may be appropriately modified in order to enhance the solubility in various solvents. Specifically, hydroxyethylation (6
5-100 g / 100 ml, 25 ° C. water), hydroxypropylation (50 g / 100 ml, 25 ° C. water) and maltosylation (1) in which maltose is bound by pullulanase enzyme.
50 g / 100 ml, 25 ° C. water) and the like, and unmodified α-cycloamylose (14.5 g / 100 ml, 2
5 ° C. water), β-cycloamylose (1.85 g / 100)
ml, 25 ° C. water), γ-cycloamylose (23.2 g
/ 100 ml, water at 25 ° C). The modified cycloamylose that can be preferably used in the present invention is particularly a maltosylated modified cycloamylose, which has a higher reaction rate in the case of immobilization on the surface of the inorganic pigment than other modified cycloamylose, and its water content. Due to its high solubility in, it is possible to perform immobilization efficiently.

Commercially available cycloamylose can be preferably used in the present invention. For example, Celldex A, Celldex N, Celldex P, Celldex G, Celldex CH-20, Celldex CH-3.
0, Celldex CH-30H, Celldex BA-1
00, Celldex TB-50, Celldex SL-2
0, Celldex SH-20, Celldex SH-20
H, Celldex SA-30, Celldex SG-30
(Above made by Nippon Shokubai), α-CD, β-CD, γ-C
D, B-CD60, G1-CD, G1-α-CD, G1
-Β-CD, G1-γ-CD, G1, G1-αCD, G
1, G1-β-CD, G1, G1-γ-CD, methyl-
β-CD, hydroxyethyl-β-CD, hydroxypropyl-β-CD, triacetyl-β-CD, DEXIPEARL KS-20, DEXIPEARL K-50, DEXIPEARL KM-50, DEXIPEARL K-100, DEXIPEARL α
-100 (made by Shimizu Kosei Sugar Co., Ltd.) and the like can be mentioned.

As an example in which cycloamylose is applied to an ink for ink jet recording, JP-A-1-210477 can be mentioned. However, if the dye is simply clathrated with cycloamylose, the dye bleeds after printing. The effect of improving the ozone resistance and the light resistance cannot be sufficiently obtained even if a water-soluble ultraviolet absorber is used together with the solid acid points of the inorganic pigment being present. Further, in view of the solubility of β-cycloamylose in water, it is difficult to achieve the conventionally known dye concentration in the ink with the clathrate dye, and the physical properties of the ink are significantly affected, which is not preferable. To the end, in the present invention, by fixing cycloamylose on the surface of the inorganic pigment in the ink receiving layer of the inkjet recording sheet, ozone resistance, light resistance, dye fixing property and the background of the inkjet recording sheet are improved. It also improves yellowing resistance.

In the present invention, the immobilization of cycloamylose on the surface of the inorganic pigment can be carried out, for example, by using an organic silane compound having an alicyclic epoxy group at least at one end. Immobilization using the organosilane compound is carried out by reacting the alkoxysilane of the organosilane compound with the hydroxyl group on the surface of the inorganic pigment by a wet method, a dry method or the like, and then adding the above inorganic pigment to a saturated solution of cycloamylose. It is carried out by dispersing and reacting the hydroxyl group of glucose forming cycloamylose with the alicyclic epoxy group on the surface of the inorganic pigment.

Specifically, an organic silane compound dissolved in a mixed solvent of water and a hydrophilic organic solvent is gradually added to an inorganic pigment stirred by a stirrer such as a Henschel mixer by a sprayer or the like and sufficiently stirred. After that, it is dried at a predetermined temperature to scatter the unreacted organosilane compound, further washed with a hydrophilic organic solvent such as methanol, purified, and re-dried with a nozzle jet dryer or the like to obtain one-end epoxy. An inorganic pigment powder modified with a group-containing organosilane compound is obtained.

Furthermore, in a saturated solution of cycloamylose using a mixed solvent of water and a hydrophilic organic solvent, an inorganic pigment modified with the above-mentioned organosilane compound containing an epoxy group at one end and sodium hydroxide as a catalyst, A basic compound such as potassium hydroxide is added, warmed to a predetermined temperature, reacted for a predetermined time, and then an acid is added to neutralize. The solution is dried with a nozzle jet dryer or the like, sufficiently washed to remove unreacted cycloamylose, and dried again to obtain the target cycloamylose-immobilized silica.

Here, the water in the mixed solvent is essential for uniformly dissolving the cyclodextrin and the basic compound which is the catalyst in the system, but when the amount is too large,
It is not preferable because hydrolysis of the organosilane compound containing an epoxy group at one end is promoted as a side reaction. The preferable amount of water is 2 to 60 times by weight, and more preferably 5 to 50 times by weight, for each of the organosilane compound and cycloamylose.

The hydrophilic organic solvent is ethanol,
Lower alcohols such as isopropanol, acetonitrile, acetone and the like can be mentioned, and the amount thereof is 1 to 6 for the organic silane compound and cycloamylose, respectively.
It is 0 times by weight, more preferably 5 to 50 times by weight.

Examples of the organic silane compound having an alicyclic epoxy group at one end include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltris (β-
Examples thereof include methoxyethoxy) silane and γ-glycidoxypropyltriacetoxysilane. As such an organic silane compound, a commercially available one can be preferably used, and for example, A-187 (manufactured by Nippon Unicar),
Examples thereof include KBM403 (manufactured by Shin-Etsu Chemical), SH6040 (manufactured by Toray Dow Corning Silicone), G-6720 (manufactured by Chisso), and GLYMO (manufactured by Dynamit Nobel).

As the basic compound of the catalyst, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium acetate and the like can be mentioned, and the addition amount thereof is based on the one-terminal epoxy-modified organosilane compound. 0.05-1.5 times the molar amount, more preferably 0.1-
It is 0.5 times the molar amount. Here, if the addition amount of the basic compound is less than 0.05 times the molar amount, the cycloamylose immobilization reaction does not proceed sufficiently, and if it exceeds 1.5 times the molar amount, the cycloamylose immobilization is rather effected. It is not preferable because the chemical reaction is inhibited, and the amount of a by-product salt at the time of neutralization increases, which makes purification difficult. The acid used for neutralization at the end of the reaction includes hydrochloric acid, sulfuric acid, nitric acid, acetic acid and the like.

The drying temperature of the inorganic pigment modified with the above-mentioned organosilane compound containing an epoxy group at one end is 80 to 1
The range of 20 ° C is preferable, and more preferably 100 to 11
0 ° C. Here, if the drying temperature is lower than 80 ° C, a large amount of unreacted organic silane compound remains, and if it exceeds 120 ° C, the reacted organic silane compound is decomposed and the inorganic pigment is colored, which is not preferable. . Further, the drying time is at least 5 hours or more, and the unreacted organosilane compound can be sufficiently scattered.

The reaction temperature for immobilizing cycloamylose on the inorganic pigment modified with the organosilane compound containing an epoxy group at one end is 5 to 70 ° C, more preferably 40 to 60 ° C. The reaction time is preferably at least 3 hours or longer.

In the present invention, the immobilization of cycloamylose on the surface of the inorganic pigment preferably occupies 20% or more, more preferably 30% or more, and preferably less than 20% of the specific surface area of the inorganic pigment by BET. In addition, the inclusion effect of the dye and the rejection rate of the solid acid points of the inorganic pigment are low, and therefore, the ozone resistance, the light resistance, the fixability of the dye, and the yellowing resistance of the background of the inkjet recording sheet are sufficiently improved. Becomes difficult.

The cycloamylose used in the present invention is
A more preferable form is cation-modified cycloamylose. As a cationizing agent for cation-denaturing cycloamylose, it is preferable to use glycidyl trimethyl ammonium chloride or 3-chloro-2-hydroxypropyl trimethyl ammonium chloride. By cation-denaturing cycloamylose, the dye is fixed. Since the property is stronger, the water resistance is further improved, and the ozone resistance and the light resistance are further improved.

The cationization modification method of cycloamylose using glycidyltrimethylammonium chloride or 3-chloro-2-hydroxypropyltrimethylammonium chloride in the present invention is described in, for example, Japanese Patent Application Laid-Open Publication No. 5 (1999) -58242.
It can be carried out by using the cationization method of cycloamylose proposed in JP-A 8-210901, and sodium hydroxide in a mixed solvent of water and a hydrophilic organic solvent,
Although it is carried out in the presence of a basic catalyst such as potassium hydroxide, this cation modification may also be carried out at the same time when cycloamylose is immobilized on an inorganic pigment modified with an organosilane compound containing an epoxy group at one end. Alternatively, cationization modification can be performed separately after immobilization.

Here, as a method for simultaneously fixing cycloamylose to an inorganic pigment modified with an organosilane compound containing an epoxy group at one end and cationizing modification of cycloamylose at the same time, water and a hydrophilic organic solvent are used. In a saturated solution of cycloamylose using a mixed solvent, with the inorganic pigment modified with an organosilane compound containing an epoxy group at one end, the above cationizing agent was added, and as a catalyst,
A basic compound such as sodium hydroxide or potassium hydroxide is added, warmed to a predetermined temperature, reacted for a predetermined time, and then acid is added to neutralize. The solution is dried by a nozzle jet dryer or the like, sufficiently washed to remove unreacted cycloamylose, and dried again to obtain the desired cationized modified cycloamylose-immobilized silica.

In the case of carrying out the cationization modification of cycloamylose as described above, the addition amount of the cationizing agent is 0.5 to 9 times mol relative to 1 mol of cycloamylose, but other water and hydrophilic organic solvents are used. The conditions such as the addition amount, the type and addition amount of the basic compound, the type of acid, the reaction temperature, and the reaction time are set in the immobilization of cycloamylose on the inorganic pigment modified with the organosilane compound containing an epoxy group at one end. It can be performed under the same reaction conditions.

Preferred inorganic pigments contained in the ink receiving layer of the ink jet recording sheet of the present invention are:
An inorganic pigment having a specific surface area by BET of 100 m ² / g or more, more preferably 200 m ² / g or more. By using an inorganic pigment having such a specific surface area, high printing density and excellent ink absorbency can be expressed,
The cycloamylose immobilized on the surface can sufficiently include the dye in the ink. BET of inorganic pigment
If the specific surface area is less than 100 m ² / g, sufficient printing density,
Ink absorbency and inclusion effect of cycloamylose 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,
Examples thereof include aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide and the like.

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 inkjet recording sheet which is excellent in the sharpness of a printed image. Examples of such synthetic amorphous silica include those disclosed in JP-A-57-157786 and JP-A-5-157786.
No. 1-141584, No. 61-230979, No. 62-292476, and the like, the three-dimensional structure of SiO ₂ is formed by gelation of silicic acid, microporosity, The particles are amorphous particles, and the typical physical property value range thereof is an average particle diameter of 10 nm to 20 μm.
Degree, Hunter whiteness 90 or more, Pore size 10-2000
It has a degree of 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 refers to particles that are suspended and dispersed in water to form a colloidal shape, and the particles have positively charged surfaces, for example, 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.

The ink receiving layer in the present invention may contain a binder resin in the ink receiving layer for the purpose of improving the adhesion between the inorganic pigments and between the ink receiving layer and the support. As the binder resin which 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; polymer or copolymer of acrylic acid ester and methacrylic acid ester, acrylic acid And acrylic polymer latex such as methacrylic acid polymer or copolymer; vinyl polymer latex such as ethylene-vinyl acetate copolymer; or carboxy of these various polymers. Functional group-modified polymer latex with functional group-containing monomers such as groups; water-based adhesives such as thermosetting synthetic resin systems such as melamine resins and urea resins; polymethyl methacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride- One or more synthetic resin adhesives such as vinyl acetate copolymer, polyvinyl butyral, and alkyd resin can be used alone or in combination. In addition, the use of known natural or 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 the amount exceeds 70 parts by weight, the ink absorption capacity is insufficient depending on the type of the inkjet recording apparatus, which is not preferable because the ink overflows.

Further, as other additives, a cationic dye fixing agent, a pigment dispersant, a thickener, a fluidity improver, a defoaming agent, a foam suppressor, a release agent, a foaming agent, a penetrating agent, a coloring dye. A color pigment, a fluorescent whitening agent, an ultraviolet absorber, an antiseptic, an antifungal agent, a water resistant agent, a wet paper strength enhancer, a dry paper strength enhancer, an antioxidant, and the like can be appropriately added.

As the support in the present invention, LBK is used.
Chemical pulp such as P, NBKP, GP, PGW, RM
P, TMP, CTMP, CMP, mechanical pulps such as CGP, wood pulp such as waste paper pulp such as DIP, and conventionally known pigments as main components, binders and sizing agents, fixing agents, yield improving agents, cationizing agents, Mixing using one or more kinds of various additives such as paper strengthening agent, a fourdrinier paper machine,
Base paper manufactured by various machines such as cylinder paper machine, twin wire paper machine, etc., and further, base paper with a size press with starch, polyvinyl alcohol, etc. and an anchor coat layer, or a coat layer on them It also includes coated paper such as art paper, coated paper and cast coated paper. Such a base paper and a coated paper may be provided with the coating layer according to the present invention as they are, or a calender device such as a machine calender, a TG calender or a soft calender may be used for the purpose of controlling the flatness. . The basis weight of the support is usually 40 to 300 g / m ² , but is not particularly limited.

As a method for 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,
Conventionally known air knife coater, curtain coater,
Die coater, blade coater, gate roll coater, bar coater, rod coater, roll coater,
It can be coated on the support by various devices such as a bill blade coater, a short dwell blade coater and a size press. Also, after coating the ink receiving layer,
The smoothing treatment can be performed 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. . Further, the ink receiving layer can be applied by coating a certain fixed amount of coating in several times.
The gloss is improved as compared with the case where the coating amount is applied at one time.

Further, by providing the 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 coated on the opposite surface of the ink receiving layer sandwiching the support in order to impart curl suitability.
A tabular pigment or hydrohalloysite is preferable, and even when 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. The dyes have good coloring properties, vividness, stability, etc., for example,
CIDirect Yellow 12, CIDirect Yellow 24, CIDire
ct Yellow 26, CIDirect Yellow 44, CIDirect Yello
w 86, CIDirect Yellow 98, CIDirect Yellow 100, C.
I.Direct Yellow 142, CIDirect red 1, CIDirect re
d 4, CIDirect red 17, CIDirect red 28, CIDirect
red 83, CIDirect Orenge 34, CIDirect Orenge 39,
CIDirect Orenge 44, CIDirect Orenge 46, CIDire
ct Orenge 60, CIDirect Violet 47, CIDirect Viole
t 48, CIDirect Blue 6, CIDirect Blue 22, CIDire
ct Blue 25, CIDirect Blue 71, CIDirect Blue 86,
CIDirect Blue 90, CIDirect Blue 106, CIDirect
Blue 199, CIDirect Black 17, CIDirect Black 19,
CIDirect Black 32, CIDirect Black 51, CIDirect
Black 62, CIDirect Black 71, CIDirect Black 10
8, direct dyes such as CIDirect Black 146, CIDirect Black 154, CIAcid Yellow 11, CIAcid Yellow 17, C.I.
I.Acid Yellow 23, CIAcid Yellow 25, CIAcid Yello
w 29, CIAcid Yellow 42, CIAcid Yellow 49, CIAci
d Yellow 61, CIAcid Yellow 71, CIAcid red1, CIA
cid red 6, CIAcid red 8, CIAcid red 32, CIAcid
red 37, CIAcid red 51, CIAcid red 52, CIAcid red
80, CIAcid red 85, CIAcid red 87, CIAcid red 9
2, CIAcid red 94, CIAcid red 115, CIAcid red 18
0, CIAcid red 256, CIAcid red 317, CIAcid red 3
15, CIAcid Orenge 7, CIAcidOrenge 19, CIAcid Vi
olet 49, CIAcid Blue 9, CIAcid Blue 22, CIAcid
Blue 40, CIAcid Blue 59, CIAcid Blue 93, CIAcid
Blue 102, CIAcid Blue 104, CIAcid Blue 113, CIA
cid Blue 117, CIAcid Blue 120, CIAcid Blue167, C.
I.Acid Blue 229, CIAcid Blue 234, CIAcid Blue 25
4, CIAcid Black 2, CIAcid Black 7, CIAcid Black
24, CIAcid Black 26, CIAcid Black31, CIAcid Bl
ack 52, CIAcid Black 63, CIAcid Black 112, CIAc
Acid dyes such as id Black 118, other basic dyes,
Water-soluble dyes such as reactive dyes or food dyes can be used.

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, tert-butyl alcohol, 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, triethylene glycol, 1, 2, 6
-Alkylene glycols having 2 to 6 alkylene groups such as hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl ether, and other polyalkylene glycols Examples thereof include lower alkyl ethers of polyhydric alcohol.

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.

As other additives to be added to the ink, for example, PH adjusting agent, sequestering agent, antioxidant,
Examples thereof include antifungal agents, viscosity modifiers, surface tension modifiers, wetting agents, surfactants, and rust preventives.

[0053]

The ink jet recording sheet of the present invention contains an inorganic pigment having a BET specific surface area of 100 m ² / g or more and a binder resin in an ink receiving layer on a support, and 20% or more of the specific surface area of the inorganic pigment. Since cycloamylose is immobilized by using an organosilane compound having an alicyclic epoxy group at one end, cycloamylose is included in the dye ozone and light attack sites, and inorganic pigment solids. The fading of the dye is remarkably suppressed in combination with the decrease of the acid point, and the dye does not exude even after adhering water or after long-term storage under high humidity conditions, and the ink jet recording sheet. It is possible to obtain an inkjet recording sheet having an improved yellowing of the background over time.

[0054]

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.

[Preparation of cycloamylose-immobilized silica]
Synthetic amorphous silica (manufactured by Tokuyama Soda, Fineseal X37B, specific surface area 270 m ² / g) in a Henschel mixer 2
While adding 0 g and stirring, γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar, A-187) 5
% Water / ethanol mixed solution (water / ethanol = 30/7
0) 150 mL was added over 10 minutes. After the addition, the mixture was further stirred for 10 minutes, and then the synthetic amorphous silica was taken out and dried at 100 ° C. for 5 hours. The obtained silica powder was thoroughly washed with ethanol to remove unreacted γ-glycidoxypropyltrimethoxysilane, and then dried again. The coating rate of γ-glycidoxypropyltrimethoxysilane in the alicyclic epoxy-modified silica thus obtained was calculated from the reduction rate of silanol groups and found to be 33.2% of the total specific surface area.

On the other hand, in 100 mL of a water / ethanol mixed solution (water / ethanol = 50/50) heated to 40 ° C., a mixed white powder of α, β and γ-cycloamylose (K-100 manufactured by Shimizu Minato Seito Sugar Co., Ltd.) , Total cycloamylose 9
Α-Cycloamylose 70% in 8%) was dissolved to prepare a saturated aqueous solution. Next, 20 g of the alicyclic epoxy-modified silica and 25 g of a 5% aqueous sodium hydroxide solution were added to the saturated solution of cycloamylose. 40 aqueous solution
The mixture was kept stirred at 6 ° C. for 6 hours with a three-one motor and then neutralized with 5% hydrochloric acid to terminate the reaction. The cycloamylose-immobilized silica in this mixed solution was dried with a nozzle jet dryer, washed thoroughly with water to remove unreacted cycloamylose, and dried again. The reaction rate of cycloamylose in the thus-obtained cycloamylose-immobilized silica was calculated from the reduction rate of alicyclic epoxy groups to be 88.4%, and the modification rate with cycloamylose was 29. It was 3%.

Example 1 80 parts of LBKP (freeness of flow 400 mlcsf) and NBKP
Pigment 20 in which the ratio of light calcium carbonate / heavy calcium carbonate / talc is 10/10/10 with respect to 100 parts of wood pulp consisting of 20 parts (freeness 480 mlcsf)
Parts, commercially available alkyl ketene dimer 0.10 parts, commercially available cationic acrylamide 0.03 parts, commercially available cationized starch 1.0 part, and sulfuric acid band 0.5 parts, and then papermaking with a Fourdrinier paper machine, basis weight 90 g A support of / m ² was obtained.

Then, an ink receiving layer coating composition 1 having the following composition was applied onto this support by an air knife coater.
Coating and drying were performed so that the dry coating amount was 8 g / m ^2, and the inkjet recording sheet of Example 1 was obtained. <Ink Receiving Layer Coating Composition 1> 20 parts of the above cycloamylose-immobilized silica 20 parts of polyvinyl alcohol (Kuraray PVA117)

Example 2 The modification ratio with cycloamylose was 2 of the specific surface area of silica.
An inkjet recording sheet of Example 2 was obtained in the same manner as in Example 1, except that 0.4% of cycloamylose-immobilized silica was used.

Example 3 The modification ratio with cycloamylose was 4 as the specific surface area of silica.
An inkjet recording sheet of Example 3 was obtained in the same manner as in Example 1 except that 0.9% of cycloamylose-immobilized silica was used.

Example 4 As the inorganic pigment, synthetic amorphous silica having a specific surface area by BET of 109 m ² / g (Carplex 1120 manufactured by Shionogi Pharmaceutical Co., Ltd.) was used, and cycloamylose-immobilized silica (cycloamylose was used according to the above method. The denaturation rate is 2
7.8%). An inkjet recording sheet of Example 4 was obtained in the same manner as in Example 1 except that this silica was used.

Example 5 As the inorganic pigment, synthetic amorphous silica having a specific surface area by BET of 125 m ² / g (P-526, manufactured by Mizusawa Chemical Co., Ltd.) was used, and cycloamylose-immobilized silica (cycloamylose) was used according to the above method. The denaturation rate was 27.9%). An inkjet recording sheet of Example 5 was obtained in the same manner as in Example 1 except that this silica was used.

Example 6 As the inorganic pigment, synthetic amorphous silica having a specific surface area by BET of 180 m ² / g (P-802 manufactured by Mizusawa Chemical Co., Ltd.) was used, and cycloamylose-immobilized silica (cycloamylose) was used according to the above method. The denaturation rate was 28.0%). An inkjet recording sheet of Example 6 was obtained in the same manner as in Example 1 except that this silica was used.

Example 7 As cycloamylose, α-cycloamylose powder (manufactured by Shimizu Minato Sugar, α-100) was used, and cycloamylose-immobilized silica (denaturation rate with α-cycloamylose was 28.8% according to the above method. ) Was produced. An inkjet recording sheet of Example 7 was obtained in the same manner as in Example 1 except that this silica was used.

Example 8 As cycloamylose, β-cycloamylose powder (manufactured by Shimizu Minato Seizo, β-100) was used, and cycloamylose-immobilized silica (denaturation rate by β-cycloamylose was 27.7% according to the above method. ) Was produced. An inkjet recording sheet of Example 8 was obtained in the same manner as in Example 1 except that this silica was used.

Example 9 As cycloamylose, γ-cycloamylose powder (γ-100, manufactured by Shimizu Minato Seito Co., Ltd.) was used, and cycloamylose-immobilized silica (denaturation rate with γ-cycloamylose was 29.7% according to the above method. ) Was produced. An ink jet recording sheet of Example 9 was obtained in the same manner as in Example 1 except that this silica was used.

Example 10 As cycloamylose, maltosylated cycloamylose powder (manufactured by Shimizu Minato Sugar, Isoeryte P, α: β: γ =
6: 3: 1) and the cycloamylose-immobilized silica according to the above method (the modification rate with cycloamylose is 2
6.6%). An inkjet recording sheet of Example 10 was obtained in the same manner as in Example 1 except that this silica was used.

Example 11 As cycloamylose, maltosylated cycloamylose powder (manufactured by Shimizu Minato Sugar, Isoeryte 40P, α: β:
γ = 3: 4: 1) was used to prepare cycloamylose-immobilized silica (denaturation rate with cycloamylose: 28.1%) according to the above method. An inkjet recording sheet of Example 11 was obtained in the same manner as in Example 1 except that this silica was used.

[Preparation of cationized cycloamylose-immobilized silica] In 100 mL of a water / ethanol mixed solution (water / ethanol = 50/50) heated to 40 ° C., α-
White powder of cycloamylose (manufactured by Shimizu Minato Sugar, α-10
0) was dissolved to prepare a saturated aqueous solution. Then, in the saturated solution of cycloamylose, glycidyl trimethyl ammonium chloride (SY-GTA8 manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) was used.
0) 2 g and a cycloaliphatic epoxy-modified silica having a coverage of 33.3% of γ-glycidoxypropyltrimethoxysilane 1
8 g and 25 g of 5% aqueous sodium hydroxide solution were added. While maintaining the aqueous solution at 40 ° C. for 7 hours, stirring was continued with a three-one motor and then neutralized with 5% hydrochloric acid to terminate the reaction. The cycloamylose-immobilized silica in this aqueous solution was dried by a nozzle jet drier, washed sufficiently with water and acetone to remove unreacted cycloamylose and glycidyltrimethylammonium chloride, and dried again. The cycloamylose modification rate of the cationized cycloamylose-immobilized silica thus obtained was 27.3%, and the cation modification rate calculated from the content of nitrogen atoms was 5% of all cycloamylose hydroxyl groups. there were.

Example 12 An inkjet recording sheet of Example 12 was obtained in the same manner as in Example 1 except that the above-mentioned cationized cycloamylose-immobilized silica was used as cycloamylose.

Example 13 As cycloamylose, β-cycloamylose powder (manufactured by Shimizu Minami Seito, α-100) was used, and cationized cycloamylose-immobilized silica (denaturation rate by β-cycloamylose was 27. 8%, and the cation modification rate was 4.6% of all cycloamylose hydroxyl groups). An inkjet recording sheet of Example 13 was obtained in the same manner as in Example 1 except that this silica was used.

Example 14 As cycloamylose, γ-cycloamylose powder (γ-100, manufactured by Shimizu Minato Seito Co., Ltd.) was used, and cationized cycloamylose-immobilized silica (denaturation rate with γ-cycloamylose was 28. 8%, and the cation modification rate was 5.1% of all cycloamylose hydroxyl groups). An inkjet recording sheet of Example 14 was obtained in the same manner as in Example 1 except that this silica was used.

Example 15 As cycloamylose, maltosylated cycloamylose powder (manufactured by Shimizu Minato Sugar, Isoeryte 40P, α: β:
γ = 3: 4: 1) and cationized cycloamylose-immobilized silica (the modification rate with maltosylated cycloamylose is 28.8%, and the cation modification rate is 6.1% of all cycloamylose hydroxyl groups) according to the above method. %) Was prepared. An inkjet recording sheet of Example 15 was obtained in the same manner as in Example 1 except that this silica was used.

Comparative Example 1 Synthetic amorphous silica (Fineseal X37, manufactured by Tokuyama Soda Co., Ltd.)
B, a specific surface area of 270 m ² / g) was used in the same manner as in Example 1 except that the inkjet recording sheet of Comparative Example 1 was obtained.

Comparative Example 2 The modification ratio with cycloamylose was 5.
An inkjet recording sheet of Example 2 was obtained in the same manner as in Example 1 except that 6% cycloamylose-immobilized silica was used.

Comparative Example 3 The modification ratio with cycloamylose was 1 of the specific surface area of silica.
An ink jet recording sheet of Example 3 was obtained in the same manner as in Example 1 except that 5.5% of cycloamylose-immobilized silica was used.

Comparative Example 4 As the inorganic pigment, synthetic amorphous silica (P-527 manufactured by Mizusawa Chemical Co., Ltd.) having a specific surface area by BET of 55 m ² / g was used, and cycloamylose-immobilized silica (cycloamylose) was used according to the above method. The denaturation rate was 27.5%). An inkjet recording sheet of Comparative Example 4 was obtained in the same manner as in Example 1 except that this silica was used.

Comparative Example 5 As the inorganic pigment, synthetic amorphous silica having a specific surface area by BET of 30 m ² / g (P-603 manufactured by Mizusawa Chemical Co., Ltd.) was used, and cycloamylose-immobilized silica (cycloamylose) was used according to the above method. The denaturation rate was 27.3%). An inkjet recording sheet of Comparative Example 5 was obtained in the same manner as in Example 1 except that this silica was used.

Comparative Example 6 An ink jet recording sheet of Comparative Example 6 was obtained in the same manner as in Example 1 except that the ink receiving layer coating composition 2 having the following composition was used. <Ink receiving layer coating composition 2> Synthetic amorphous silica (manufactured by Soda Tokuyama, Fineseal X37B) 100 parts Polyvinyl alcohol (manufactured by Kuraray, PVA117) 20 parts β-cycloamylose (manufactured by Shimizu Minato Sugar, γ-100) 10 copies

Comparative Example 7 An ink jet recording sheet of Comparative Example 7 was obtained in the same manner as in Example 1 except that the ink receiving layer coating composition 3 having the following composition was used. <Ink receiving layer coating composition 3> Synthetic amorphous silica (manufactured by Soda Tokuyama, Fineseal X37B) 100 parts polyvinyl alcohol (manufactured by Kuraray, PVA117) 20 parts mantosylated cycloamylose (manufactured by Shimizu Minato Sugar, Isoeryte P) 10 copies

[Preparation of cationized cycloamylose] 4
In 100 mL of a water / ethanol mixed solution (water / ethanol = 50/50) heated to 0 ° C., a white powder of α-cycloamylose (α-100, manufactured by Shimizu Minato Seikatsu Co., Ltd.) was dissolved to prepare a saturated aqueous solution. Then, in this saturated solution of cycloamylose, 2 g and 5% of glycidyl trimethyl ammonium chloride (SY-GTA80 manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)
25 g of aqueous sodium hydroxide solution was added. 4 aqueous solution
The mixture was kept stirred at 0 ° C. for 5 hours with a three-one motor and then neutralized with 5% hydrochloric acid to terminate the reaction.
The cationized cycloamylose in this aqueous solution was dried by a nozzle jet drier, washed sufficiently with acetone to remove unreacted glycidyl trimethyl ammonium chloride, and dried again. The cation modification ratio of the cationized cycloamylose thus obtained was 6.8% of all cycloamylose hydroxyl groups.

Comparative Example 8 An ink jet recording sheet of Comparative Example 8 was obtained in the same manner as in Example 1 except that the ink receiving layer coating composition 4 having the following composition was used. <Ink receiving layer coating composition 4> Synthetic amorphous silica (manufactured by Tokuyama Soda, Fineseal X37B) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 20 parts The above cationized cycloamylose 10 parts

Comparative Example 9 As cycloamylose, maltosylated cycloamylose powder (manufactured by Shimizu Minato Sugar, Isoeryte 40P, α: β:
γ = 3: 4: 1) was used to prepare cationized cycloamylose (cation modification rate: 6.3% of all cycloamylose hydroxyl groups) according to the method described above. An inkjet recording sheet of Comparative Example 9 was obtained in the same manner as in Comparative Example 8 except that this cationized cycloamylose was used.

Evaluations of Examples 1 to 15 and Comparative Examples 1 to 9 were carried out by the methods described below, and the evaluation results are summarized in Table 1.

<Inkjet recording sheet yellowing resistance of the background> A polypropylene plastic file bag (A4 size) containing 1.0% by weight of BHT has a center of 5 on one side.
Cut into squares of 5 cm x 5 cm, put in a file bag so that the ink receiving layer surface of each inkjet recording sheet may hit the file surface with holes, and at 20 ° C, 6
L * a * b * (CIE1976) of the ink-receiving layer before and after the treatment for 2 months in an environment of 5% RH was measured by a color difference meter, CR-100 manufactured by Minolta. The degree of yellowing of the background can be represented by the difference in b * before and after the treatment (Δb *), and the smaller this value is, the less yellowing is.
Inkjet printer (MJ-700V2C, EP
SON) to perform solid printing with black ink,

<Water resistance> An inkjet printer (manufactured by EPSON, MJ-
Solid printing of magenta ink was performed at 700V2C).
The degree of ink bleeding after immersion in running water at 20 ° C. for 30 minutes was visually evaluated. A: No bleeding is observed. ◯: Bleeding is slightly seen in the edge part. Δ: Bleeding is large and a decrease in density can be recognized. X: Bleeding and decrease in density are severe.

Further, the optical density of the printed portion before and after the immersion was measured by Macbeth RD-919, and the residual ratio D of the magenta ink was calculated from the following formula 1.

[0088]

## EQU1 ## D = D ₂ / D ₁ × 100 where D ₁ is the optical density before immersion in running water and D ₂ is the optical density after immersion in running water.

<Ozone resistance> Each inkjet recording sheet is provided with an inkjet printer (Made by EPSON, M
J-700V2C) was used for solid printing of magenta ink. These ink jet recording sheets were placed in a glass container having an ozone inlet and an outlet, and ozone generated by Mitsubishi Electric Ozonizer OS-1 was continuously introduced for 15 minutes. The ozone concentration at this time is about 80 ppm
Met. The color difference of magenta ink color before and after ozone treatment of these ink jet recording sheets was measured. 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 light irradiation according to L * a * b * (CIE1976). The larger the color difference, the more the color deterioration occurs. If the color difference is less than 1.0, the
It is almost impossible to recognize the difference in color.

[0090]

[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.

<Light resistance> An ink jet printer (manufactured by EPSON, MJ-
Solid printing of magenta ink was performed at 700V2C).
These ink jet recording sheets were used with a xenon arc fade meter, Atlas Ci-35f,
The color difference of the magenta ink color before and after light irradiation for 30 hours was measured under the environment of a black panel temperature of 63 ° C. and a relative humidity of 65% RH. The color difference is measured according to the ozone resistance test.

[0092]

[Table 1]

As is clear from Table 1, Examples 1 to 15
The inkjet recording sheet using the cycloamylose-immobilized silica of the present invention had better yellowing resistance of the background, water resistance, ozone resistance and light resistance than the comparative examples. In particular, among the inkjet recording sheets of Examples 1 to 3, the inkjet recording sheet of Example 3 using silica having the highest modification rate with cycloamylose was excellent. Among the ink jet recording sheets of Examples 1 and 4 to 6, the ink jet recording sheet of Example 1 having the highest specific surface area of the inorganic pigment was excellent. Among the ink jet recording sheets of Examples 7 to 9, the ink jet recording sheet of Example 8 using silica having the highest modification ratio with β-cycloamylose was excellent. In the ink jet recording sheets of Examples 10 and 11, maltosylated cycloamylose was used as cycloamylose, so that the ink jet recording sheet of Example 11 having a particularly high ratio of maltosylated β-cycloamylose was good. The most excellent ink jet recording sheet of all Examples was the ink jet recording sheet of Example 15 containing a large amount of cation-modified maltosylated β-cycloamylose. However, in the inkjet recording sheet of Comparative Example 1, since untreated silica was used, the yellowing resistance of the background, water resistance, ozone resistance and light resistance were all inferior. In addition, in the ink jet recording sheets of Comparative Examples 2 and 3, silica modified with cycloamylose was used, but the modification ratio with cycloamylose was low, and thus sufficient improvement was not made. In the ink jet recording sheets of Comparative Examples 4 and 5, cycloamylose was immobilized, but the specific surface area of the inorganic pigment was too low, so that the dye in the ink could not be sufficiently included,
Water resistance, ozone resistance and light resistance were poor. In the ink jet recording sheets of Comparative Examples 6 and 7, although ozone resistance and light resistance were improved because cycloamylose was simply added to the ink receiving layer coating composition,
Since the solid acid points of silica are not eliminated, the yellowing resistance of the background is not improved, and in the water resistance test, since the dye flows out while being included in cycloamylose, the ink bleeding and optical density A drop was seen. Also in the ink jet recording sheets of Comparative Examples 8 and 9, since the cationized cycloamylose was only added to the ink receiving layer coating composition, the ink resistance of the ink jet recording sheets of Comparative Examples 6 and 7 was improved. Although ozone resistance and light resistance were improved, yellow resistance and water resistance of the background were not improved.

[0094]

According to the present invention, the ink receiving layer of the ink jet recording sheet is mainly composed of an inorganic pigment and a binder resin, and the inorganic pigment fixes cycloamylose at a specific ratio of specific surface area or more. Since the solid acid points on the silica surface are eliminated and the dye in the ink is strongly included in cycloamylose, it is resistant to yellowing of the background, water resistance, ozone resistance and light resistance. It is possible to obtain an excellent inkjet recording sheet.

Claims (4)

[Claims] 1. An ink jet recording sheet having an ink receiving layer provided on a support, wherein the ink receiving layer composition is mainly composed of an inorganic pigment having a specific surface area of 100 m ² / g or more by BET and a binder resin, and An ink jet recording sheet, characterized in that the inorganic pigment has cycloamylose immobilized on 20% or more of its specific surface area. 2. The ink jet recording sheet according to claim 1, wherein the cycloamylose is β-cycloamylose. 3. The ink jet recording sheet according to claim 1 or 2, wherein the cycloamylose is maltosyl-modified cycloamylose. 4. The cycloamylose is cation-modified cycloamylose, which is characterized in that:
4. The inkjet recording sheet according to any one of 3 to 3.