JPH0939377A - Sheet for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet for ink jet recording with excellent transparency, luster, ink absorbing characteristics, moisture and water resistance. SOLUTION: In a sheet for ink jet recording in which a water-soluble resin- contg. ink receiving layer is provided on a substrate, the ink receiving layer is constituted of at least two layers. In addition, one layer of them (the top layer) exhibits higher water insolubility than that of another layer (the sublayer) being on its substrate side and a water-soluble resin incorporated in at least one layer of the ink receiving layer is at least one selected from hydroxypropyl methyl cellulose, methyl cellolose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose and polyvinyl alcohol.

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 particularly to transparency, glossiness, ink absorption,
The present invention relates to an inkjet recording sheet having excellent moisture resistance and water resistance.

[0002]

2. Description of the Related Art The ink jet recording system is a system for recording ink droplets ejected at high speed from a nozzle by adhering it to a recording material, and has features such as easy full colorization and low printing noise. . In this method, since the ink used contains a large amount of solvent, it is necessary to use a large amount of ink in order to obtain a high recording density. In addition, since the ink droplets are continuously ejected, the next droplet is ejected before the first droplet is absorbed, and the ink droplets are likely to be fused to join the ink dots. Therefore, the ink jet recording sheet is required to have a large ink absorption amount and a high ink absorption speed.

A plain paper type is widely used as an ink jet recording sheet. In addition, glossy printed matter is required for various publications and applications such as packaging. Particularly in the field of color recording, there is a strong need for films and coated paper types from the viewpoint of ink acceptability such as dot shape, dot sharpness, ink absorption, fixing speed, and ink absorption capacity.

In general, a transparent or high-gloss base material itself has no absorbability, so that special consideration is required when it is applied to a recording system which requires high ink absorbency such as an ink jet recording sheet. . Has the desired transparency,
In order to obtain a high-gloss ink receiving layer, either a water-soluble resin capable of forming a film or a resin soluble in an organic solvent such as polyvinyl acetate or polymethyl methacrylate can be used.

For example, Japanese Patent Laid-Open No. 61-287782 discloses a recording sheet provided with a cellulose derivative-containing layer on a transparent substrate, and even if these water-soluble resins are used,
The ink absorption and the moisture resistance cannot be balanced, and only those having poor water resistance can be obtained. Further, the organic solvent-soluble resin cannot obtain sufficient ink absorbency.

Therefore, using the above resin as a binder,
Recording sheets in which various inorganic pigments and organic pigments are mixed are known. As described in JP-A-63-162276, a recording material containing silica in a water-soluble resin is disclosed, and JP-A-6-297831 discloses a recording material containing pseudo-boehmite mixed with a water-soluble resin as a binder. An inkjet recording sheet having a layer formed on a support is disclosed. However, if a large amount of pigment is blended, the ink-receiving layer cannot have film-forming properties, transparency and gloss. On the contrary, if the blending amount is too small, the ink absorption and the water resistance cannot be balanced.

Japanese Unexamined Patent Publication (Kokai) No. 2-55186 discloses a recording sheet having a two-layer structure of an ink holding layer and an ink transport layer. Ink and solvent ejected at high speed from an inkjet printer collide with the ink transport layer and are absorbed by the capillarity to be fixed on the ink holding layer.However, if the transparency of the ink transport layer is increased, the absorption speed of the ink and solvent will increase. There was a problem of being late. Also,
Japanese Unexamined Patent Publication No. 57-89954 proposes to form a polymeric absorption layer and a transmission layer, but there is a problem in that the water resistance is poor.

[0008]

When an aqueous solution of a water-soluble resin is applied onto a support such as paper or film to form an ink receiving layer, the ink absorbency, gloss and transparency are good. However, only those having poor moisture resistance and poor water resistance can be obtained. On the other hand, when a crosslinking agent is added to a water-soluble resin to crosslink the resin, a receiving layer having good gloss and transparency can be obtained, but the ink absorbency is insufficient and ink dots are bonded to each other. , Only unclear record is obtained. In the case of a recording sheet in which a pigment is added to a water-soluble resin to form an ink receiving layer or a two-layer structure including an ink passing layer and a receiving layer, satisfactory results are obtained as described above. Absent.

The present invention solves the above-mentioned problems in an ink jet recording sheet for forming a recorded image by using a water-based ink containing a water-soluble dye, and improves transparency, glossiness, ink absorption, moisture resistance and water resistance. An object is to provide an excellent inkjet recording sheet.

[0010]

The present invention includes the following aspects. [1] In an inkjet recording sheet having a support provided with an ink receiving layer containing a water-soluble resin, the ink receiving layer is composed of two or more layers, one layer (upper layer) of which is closer to the support. The water-insoluble resin having a higher water insolubilization rate than the other layer (lower layer) and contained in at least one layer of the ink receiving layer is at least one selected from hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose and polyvinyl alcohol. Is an inkjet recording sheet.

[2] At least the water-soluble resin in the upper layer is cross-linked, and the water-insolubilization rate is adjusted by increasing the cross-linking density of the water-soluble resin contained in the upper layer over the cross-linking density in the lower layer [1]. The inkjet recording sheet described above. [3] The inkjet recording sheet according to [1] or [2], wherein the water-soluble resin contained in at least one of the ink receiving layers is at least one selected from hydroxypropyl cellulose and hydroxypropylmethyl cellulose.

[4] The water insolubilization rate of the upper layer is 85% or more, and the water insolubilization rate of the lower layer is 0 to 60% [1],
The ink jet recording sheet according to [2] or [3].

[5] The ink jet recording sheet according to [1] or [2], wherein the water-soluble resin contained in at least one of the ink receiving layers is hydroxypropylmethyl cellulose. [6] The water-soluble resin in the upper layer and the water-soluble resin in the lower layer are at least one selected from hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, and polyvinyl alcohol, respectively. [1] or [2] Inkjet recording sheet.

[7] The ink jet recording sheet according to [1] or [2], wherein the upper layer water-soluble resin and the lower layer water-soluble resin are at least one selected from hydroxypropylmethyl cellulose and hydroxypropyl cellulose. [8] The water-soluble resin in the upper layer and the water-soluble resin in the lower layer are each hydroxypropylmethyl cellulose [1]
Alternatively, the ink jet recording sheet according to [2].

[9] The inkjet recording sheet according to [1] or [2], wherein the inkjet recording sheet is an inkjet recording sheet for forming a recorded image using a water-based ink. [10] The ink jet recording sheet according to [2], wherein the upper layer water-soluble resin is crosslinked with a melamine resin.

The water insolubility of the ink receiving layer in the present invention was measured by the following method. First, the coating liquid for ink receiving layer is applied to a PET film, dried, and then the receiving layer is stripped off with a cutter and cut into 10 cm × 10 cm to obtain an absolutely dry weight (110 ° C., measured after drying for 1 hour, the same below). taking measurement. Then, the receptive layer is immersed in tap water at 20 ° C. for 16 hours, the absolute dry weight of the receptive layer after the immersion is measured, and the water insolubilization rate is calculated by the following formula. Water insolubilization rate (%) = (weight of ink receiving layer after immersion / weight of ink receiving layer before immersion) × 100

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION First, a water-soluble resin-containing ink receiving layer having a low water insolubilization rate is formed on a support (paper, film, etc.), and a water-soluble resin containing ink receiving layer having a high water insolubilization rate is formed thereon. By forming a sheet, an inkjet recording sheet excellent in transparency, glossiness, ink absorbency, and moisture / water resistance can be obtained. That is, when printing with an inkjet printer, ink droplets hit the water-soluble resin-containing ink receiving layer having a high water insolubilization rate, part of the ink and solvent in the ink is absorbed in this layer, and the remaining ink and solvent are absorbed. Is rapidly absorbed by the water-soluble resin-containing ink receiving layer having a lower water insolubilization rate than that of the upper layer, and clear printing can be obtained.

The ink receiving layer in which the water-insoluble rate of the water-soluble resin is high not only absorbs a part of ink and solvent, but also
It also greatly contributes to moisture resistance and water resistance. On the other hand, the water-soluble resin-containing receiving layer (lower layer), which has a relatively low water insolubilization rate, absorbs ink or solvent that the upper layer cannot absorb. With the above configuration, an ink jet recording sheet having good ink absorbency, moisture resistance and water resistance can be obtained.

Next, the basic structure of the present invention will be described with reference to FIG. As shown in FIG. 1, the recording sheet of the present invention is
An ink receiving layer a (preferably a water insolubilization rate of 0 to 60%, referred to as a lower layer) containing a water-soluble resin having a low water insolubilization rate shown by 2 on a support 1 (paper, film, etc.) and 3 are shown. The ink receiving layer b is obtained from a water-soluble resin and has a high water insolubility ratio (preferably a water insolubility ratio of 85 to 100%, but higher than the lower layer). Here, the receiving layer b (upper layer) needs to have a higher water insolubilization rate than the receiving layer a (lower layer). If necessary, a receiving layer c (not shown in the drawing) may be further provided on the receiving layer b (upper layer). An undercoat layer containing a pigment and the like in the resin may be provided on the support.

Materials and coating methods used in the present invention will be described. As the support, high-quality paper, coated paper, synthetic paper, polymer film, polymer resin laminated paper, or the like is used. In order to obtain glossiness, coated paper (art paper, coated paper etc.), polymer film (polyester, polyethylene, polypropylene etc.) and polymer resin laminated paper are particularly preferable.

Examples of the water-soluble resin include cellulose derivatives such as hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose and hydroxypropylcellulose, starch and starch derivatives, proteins such as casein, polyvinyl alcohol, gelatin, polyacrylamide, polyvinylpyrrolidone and water-soluble resins. Examples thereof include polyester, water-soluble nylon and water-soluble silk.

However, in the present invention, at least one selected from hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose and polyvinyl alcohol is used for at least one layer of the ink receiving layer in view of the balance between ink absorbency, moisture resistance and water resistance. Include. In particular, hydroxypropyl cellulose and hydroxypropyl methyl cellulose are preferable because they are excellent in ink absorption and gloss. Hydroxypropyl methylcellulose is most preferred.

When the upper layer and the lower layer are formed of the same kind of water-soluble resin, the gloss and transparency are excellent. The method for producing the cellulose derivative is not particularly limited.For example, in the case of etherified cellulose, it is obtained by treating cellulose as a raw material, treating it with caustic soda, and then reacting it with an etherifying agent such as methyl chloride, propylene oxide or ethylene oxide. It is a nonionic water-soluble cellulose ether. Methylcellulose has a structure in which a hydroxyl group of cellulose is replaced with a methoxyl group by introducing a methyl group. Hydroxypropyl methylcellulose is the one in which a methyl group and a hydroxypropyl group are similarly introduced, and hydroxyethylmethylcellulose is the one in which a methyl group and a hydroxyethyl group are similarly introduced. Degree of substitution (average number of hydroxy groups in glucose ring units of cellulose substituted with methoxy groups)
Is not particularly limited, but can be about 1.0 to 2.0. The degree of molar substitution of the hydroxyalkoxyl group (Molar
Substitution, the number of moles of hydroxyalkoxyl group added per glucose ring unit of cellulose) is not limited, but when a methyl group is introduced, about 0.13 ~
An example is about 0.37. When there is no other substituent, the molar degree of substitution of the hydroxyalkoxyl group is, for example, about 1.9 to 4.2. When the hydroxyalkoxyl group is substituted, the molar degree of substitution can be 4 or more because the hydroxyl group is not reduced even after the substitution.

The receiving layer a and the receiving layer b are formed by dissolving the above water-soluble resin in water, adding a pigment, a cross-linking agent and a catalyst, if necessary, and coating the solution. Alternatively, a water-soluble resin or pigment may be dissolved and dispersed in water and then applied to form a film on which a cross-linking agent and a catalyst are further applied to form a film.

In order to crosslink the water-soluble resin, a glyoxal-based, melamine-based, polyamide-based or urea-based crosslinking agent is appropriately used. The melamine resin is one in which hydrogen of melamine is replaced with CH ₂ OR (R is hydrogen or an alkyl group), and methylol melamine obtained by reacting melamine and formalin can be exemplified, and these are effective for obtaining a high crosslink density. Is. Specifically, the product name Sumite
x Resin M-3 can be illustrated (made by Sumitomo Chemical Co., Ltd.). In addition, an organic amine-based catalyst, a metal salt-based catalyst, or the like is appropriately used in order to promote crosslinking. Organic amine catalysts exemplified by amine hydrochloride, alkanolamine hydrochloride and the like are effective for melamine resin, magnesium chloride,
The metal salt catalysts exemplified by zinc nitrate, aluminum sulfate, aluminum chloride and the like are effective as the glyoxal crosslinking agent.

The addition amount of the cross-linking agent depends on the water-soluble resin and the cross-linking agent to be used, but in general, in the receiving layer a, 0 to 10 parts by weight is suitable for 100 parts by weight of the water-soluble resin. If it is added in an amount of 10 parts or more, the cross-linking density of the coating film is too high, and sufficient ink absorption may not be obtained. Similarly to the receiving layer a, the receiving layer b is also preferably 1 to 50 parts by weight based on 100 parts by weight of the water-soluble resin, although it depends on the kind of the water-soluble resin and the crosslinking agent. When the amount of the cross-linking agent is small, the cross-linking density is low, and sufficient moisture resistance and water resistance may not be obtained. On the contrary, when the amount is large, the effect is saturated.

When a catalyst is used, it depends on the kind of the cross-linking agent, but generally the cross-linking agent 100 is used for both the receiving layer a and the receiving layer b.
1 to 20 parts by weight is preferable with respect to parts by weight. If the amount is small, it is difficult to obtain the effect of promoting crosslinking, and if the amount is large, the effect is saturated, which is meaningless. Of course, in order to obtain the ink receiving layer having a desired water insolubilization rate, the addition amount of the crosslinking agent or the catalyst is not limited to the above amount.

In the present invention, the crosslinking density can be adjusted by adjusting the crosslinking temperature (drying temperature or the like), increasing the addition amount of the crosslinking agent, or selecting the crosslinking agent.

As long as the film-forming properties, glossiness and transparency of the ink receiving layer are not impaired, pigments may be appropriately added to increase the ink absorption rate. As the pigment, silica (colloidal silica etc.), alumina sol, clay, talc, calcium carbonate, pseudo-boehmite, satin white, aluminum silicate, magnesium hydroxide, magnesium carbonate,
Inorganic pigments such as zinc oxide and organic pigments such as styrene, acrylic acid ester and plastic pigment are used as appropriate.

The addition amount of the pigment is preferably 350 parts by weight or less with respect to 100 parts by weight of the water-soluble resin in both the receiving layer a and the receiving layer b. When the amount of the pigment is large, the film-forming property, glossiness and transparency of the ink receiving layer may be deteriorated, and the desired inkjet recording sheet may not be obtained.

In addition, additives such as an ink fixing agent, a dispersant, a defoaming agent, a coloring agent, an antioxidant, an ultraviolet absorber and a viscosity adjusting agent are appropriately used according to the required performance.

The coating amount of the ink receiving layer is not particularly limited, but the coating amount of the receiving layer a is about 1 to 50 g / m ² , preferably 5 to 20 g / m ² . If the amount is small, the ink absorbency may be insufficient, and if the amount is large, the effect is saturated. The coating amount of the receiving layer b is preferably about 0.5 to 10 g / m ² . If the amount is too small, the moisture resistance and water resistance of the ink receiving layer may not be sufficiently obtained, and if the amount is too large, the ink absorbing speed by the receiving layer b may be slow, and there is a risk of defective drying or uneven printing.

The method for applying the ink receiving layer is not particularly limited, and a bar coater, an air knife coater, a blade coater, a slit die coater, a lip coater, a comma coater, a roll coater, a gravure coater and the like can be used. The sheet provided with the ink receiving layer on the substrate can be used as it is as the recording sheet of the present invention, but it can be treated with a super calender, a gloss calender or the like in order to improve the surface smoothness.

Examples of dyes contained in the aqueous ink include direct dyes and acid dyes. Specific examples include direct black, hood black, acid yellow, acid red, acid blue, and direct blue. Water, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monoethyl ether, methyl carbitol, ethyl carbitol, butyl carbitol, triethylene glycol monomethyl ether, glycerin, formamide, N-methyl-2-pyrrolidone, etc. Can be illustrated. Inorganic salts such as salt can be added to the ink.

[0034]

EXAMPLES The present invention will be described in more detail with reference to examples. Here, unless otherwise specified, a water-soluble resin,
All pigments, crosslinking agents, catalysts, etc. are shown in parts by weight of solid content. The inkjet recording sheets obtained in Examples and Comparative Examples (excluding Comparative Examples 4 and 5) were all treated with a super calendar (linear pressure: 20 kg / cm) and then used for evaluation. The coating amount indicates the dry coating amount. The water insolubilization rate was measured by separately coating the PET film according to the method described above.

Example 1 Hydroxypropylmethylcellulose (degree of substitution of methoxyl group: 1.9, degree of substitution of hydroxypropoxyl group: 0.25,
Trademark: Metroze 60SH, Shin-Etsu Chemical Co., Ltd.) 10
0 part, colloidal silica (Snowtex AK, manufactured by Nissan Kagaku Co., Ltd.) 50 parts of a 5% aqueous solution was prepared, and a commercially available coated paper (trade name: OK coat, so that the coating amount was 10 g / m ² with a bar coater). 127.9 g / m ² , made by Shin-Oji Paper Co., Ltd.) and laminated on polyethylene-laminated paper (hereinafter referred to as laminated paper) at 130 ° C. for 3
After drying for a minute, a receiving layer a was obtained. Furthermore, a melamine resin-based cross-linking agent (Sumit) was added to a mixed solution of 100 parts of the above-mentioned hydroxypropylmethyl cellulose and 50 parts of colloidal silica.
ex Resin M-3, manufactured by Sumitomo Chemical Co., Ltd.) 10
Part, organic amine-based catalyst (Sumitex Accele
(rator ACX, manufactured by Sumitomo Chemical Co., Ltd.) was added and coated on the receptor layer a by a bar coater so that the coating amount was 2 g / m ^2, and dried at 130 ° C. for 5 minutes to obtain a receptor layer b. . In the ink jet recording sheet thus obtained, the water insolubilization rate of the ink receiving layer a was 0%, and the water insolubilization rate of the receiving layer b was 95%.

Example 2 Hydroxypropyl cellulose (hydroxypropoxy
The molar substitution degree of the ru group is 2.7, trade name: HPC, Shin-Etsu Chemical
100 parts, colloidal silica 50 parts, cross-linking agent
Melamine resin (Sumitex Resin M-
3, Sumitomo Chemical Co., Ltd.) 0.2 parts, organic amine catalyst
(Sumitex Accelerator ACX, housing
Tomo Chemical Co., Ltd.) Prepare 0.02 parts of 5% aqueous solution,
-Coater coating amount 10g / m² So that the above Lami
Coated on nate paper and dried at 130 ° C for 5 minutes to obtain a receiving layer a
I got Furthermore, the hydroxypropylmethyi described in Example 1
Le Cellulose (Trademark: Metroze 60SH, Shin-Etsu Chemical
Industrial Co., Ltd.) 100 parts, colloidal silica 50 parts, melami
Resin cross-linking agent (Sumitex Resin M-
3, Sumitomo Chemical Co., Ltd.) 1 part, organic amine catalyst (Su
mitex Accelerator ACX, Sumitomo
Gaku Kogyo Co., Ltd.) Prepare 0.1 part of a 5% aqueous solution, and
Coating amount 2 g / m ² Coated on the receiving layer a so that
And dried at 130 ° C. for 5 minutes to obtain a receiving layer b. Got
Water-insoluble of ink receiving layer a of ink jet recording sheet
The insolubilization rate is 50%, and the water insolubilization rate of the receiving layer b is 85%.
there were.

Example 3 Instead of hydroxypropylmethylcellulose in Example 1, methylcellulose (degree of substitution of methoxyl group: 1.8) was used.
An ink jet recording sheet was manufactured in the same manner as in Example 1 except that the trade name: Metroz SM, manufactured by Shin-Etsu Chemical Co., Ltd. was used. The water insolubilization rate of the ink receiving layer a is 0%
And the water insolubilization rate of the receiving layer b was 95%.

Example 4 Instead of hydroxypropylmethylcellulose in Example 1, hydroxyethylmethylcellulose (methoxyl group substitution degree 1.4, hydroxyethoxyl group mole substitution degree 0.
20, product name: Metroze SEB, manufactured by Shin-Etsu Chemical Co., Ltd.)
An ink jet recording sheet was produced in the same manner as in Example 1 except that was used. In the ink jet recording sheet thus obtained, the water insolubilization rate of the ink receiving layer a was 0%, and the water insolubilization rate of the receiving layer b was 95%.

Example 5 Instead of hydroxypropylmethylcellulose in Example 1, hydroxypropylcellulose (having a molar substitution degree of hydroxypropoxyl groups of 2.7, trade name: HPC,
An inkjet recording sheet was manufactured in the same manner as in Example 1 except that (Shin-Etsu Chemical Co., Ltd.) was used. In the ink jet recording sheet thus obtained, the water insolubilization rate of the ink receiving layer a was 0%, and the water insolubilization rate of the receiving layer b was 95%.

Example 6 Polyvinyl alcohol (PVA 117, manufactured by Kuraray Co., Ltd.)
100 parts of a 5% aqueous solution of 50 parts of the colloidal silica
Adjusted and coated with bar coater 10g / m² So that
Then, apply to the above laminated paper and dry at 120 ° C for 2 minutes
Then, a receiving layer a was obtained. Further, the above polyvinyl alcohol
Solution of 100 parts of colloidal silica and 50 parts of colloidal silica.
Min-resin cross-linking agent (Sumitex Resin M-
3, Sumitomo Chemical Co., Ltd.) 20 parts, organic amine catalyst (S
umitex Accelerator ACX, Sumitomo
(Chemical Industry Co., Ltd.) 2 parts added, coating amount 2 g with a bar coater
/ M ² On the receptor layer a so that
It was dried for 5 minutes to obtain a receiving layer b. The resulting inkjet
The water insolubilization rate of the ink receiving layer a of the recording sheet was 0%.
Thus, the water insolubilization rate of the receiving layer b was 98%.

Example 7 A 5% aqueous solution of 100 parts of hydroxypropylmethyl cellulose (trade name: Metroze 60SH, manufactured by Shin-Etsu Chemical Co., Ltd.) and 50 parts of colloidal silica was prepared, and the coating amount was 10 g / m ² with a bar coater. It was applied to laminated paper and dried at 130 ° C. for 3 minutes to obtain a receiving layer a. Further, the above hydroxypropyl methylcellulose 100
Part, colloidal silica 50 parts, melamine resin-based cross-linking agent (Sumitex Resin M-3, Sumitomo Chemical Co., Ltd.) 0.5 part, organic amine catalyst (Sumitex)
Accelerator ACX, Sumitomo Chemical Co., Ltd.)
0.05 part of a 5% aqueous solution was prepared, and coated on a receptor layer a with a bar coater so that the coating amount was 2 g / m ^2.
After drying at 5 ° C for 5 minutes, a receiving layer b was obtained. The water-insolubilization rate of the ink receiving layer a of the obtained ink jet recording sheet was 0%.
And the water insolubilization rate of the receiving layer b was 65%.

Comparative Example 1 A 5% aqueous solution of 100 parts of hydroxypropylmethyl cellulose (trade name: Metroze 60SH, manufactured by Shin-Etsu Chemical Co., Ltd.) and 50 parts of colloidal silica was prepared and coated with a bar coater so that the coating amount was 15 g / m ^2. It was applied to laminated paper and dried at 130 ° C. for 5 minutes to obtain a receiving layer. The water-insolubilization rate of the ink receiving layer of the obtained inkjet recording sheet was 0%.

Comparative Example 2 100 parts of hydroxypropylmethyl cellulose (trademark: Metroze 60SH, manufactured by Shin-Etsu Chemical Co., Ltd.), 50 parts of colloidal silica, melamine resin cross-linking agent (Sumite)
x Resin M-3, manufactured by Sumitomo Chemical Co., Ltd.) 50
Part, organic amine catalyst (Sumitex Accel
5% of 5 parts of "erator ACX" (Sumitomo Chemical Co., Ltd.)
An aqueous solution was prepared. The prepared solution was applied to the above-mentioned laminated paper with a bar coater so that the applied amount was 15 g / m ^2, and dried at 130 ° C for 5 minutes to obtain a receiving layer. The water-insolubilization rate of the ink receiving layer of the obtained inkjet recording sheet was 98%.

Comparative Example 3 100 parts of hydroxypropylmethyl cellulose (trademark: Metroze 60SH, manufactured by Shin-Etsu Chemical Co., Ltd.), 50 parts of colloidal silica, melamine resin cross-linking agent (Sumite)
x Resin M-3, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts,
Organic amine-based catalyst (Sumitex Accelera)
(tor ACX, manufactured by Sumitomo Chemical Co., Ltd.) 1 part of a 5% aqueous solution was prepared, coated on a laminated paper with a bar coater to a coating amount of 5 g / m ^2, and dried at 130 ° C. for 5 minutes to obtain a receiving layer a. . Furthermore, a 5% aqueous solution of 100 parts of hydroxypropylmethyl cellulose and 50 parts of colloidal silica was prepared, and was coated on the receptor layer a by a bar coater so that the coating amount was 5 g / m ^2, and dried at 130 ° C. for 3 minutes, Receptive layer b
I got The water-insolubilization rate of the ink receiving layer a of the obtained ink jet recording sheet was 95%, and the water-insolubilization rate of the receiving layer b was 0%.

Comparative Example 4 Commercially available high-gloss inkjet recording sheet (commercial name: GP-101, sold by Canon Inc.) having a coating layer containing alumina, silica, polyvinyl alcohol, etc. formed on a high-quality paper support. ) Was used.

Comparative Example 5 Commercially available high-gloss inkjet recording sheet having a resin coating layer such as polyvinyl alcohol formed on a PET film (trade name: HG-101, sold by Canon Inc.)
Was used.

Comparative Example 6 A 5% ethanol solution of a water-insoluble nylon resin (trade name: Toresin F30, manufactured by Teikoku Kagaku Co., Ltd.) was prepared and coated on the above-mentioned laminated paper with a bar coater to a coating amount of 15 g / m ^2. Then, it was dried at 100 ° C. for 1 minute to form a receiving layer. The water insolubilization rate of the ink receiving layer of the obtained ink jet recording sheet was 100%.

Comparative Example 7 An ink jet recording sheet was produced in the same manner as in Example 1 except that starch (trade name: Ace A, manufactured by Oji Corn Starch Co., Ltd.) was used in place of the hydroxypropylmethyl cellulose used in Example 1. The water-insolubilization rate of the ink receiving layer a of the obtained ink jet recording sheet was 0%, and the water-insolubilization rate of the receiving layer b was 95%.

[Evaluation Method] Regarding the transparency, glossiness, ink absorbency, water resistance, and ink blurring of the ink jet recording sheets obtained in each Example and Comparative Example, a commercially available ink jet printer (type: BJC- Recording was carried out at 600 J, manufactured by Canon Inc.) and evaluated by the following methods.

Ink absorbency The time until the printed ink dries was measured and evaluated (printing was carried out on three recording sheets in a room at 20 ° C. and 65% for 7 seconds and 15 seconds immediately after printing, respectively). After 60 seconds, each of the high-quality papers was overlaid and pressed, and the time until ink was not adhered to the high-quality paper was measured). A: Dry in 7 seconds or less. ◯: Dry in 7 to 15 seconds. Δ: Dry in 15 to 60 seconds. X: It takes 60 seconds or more.

Water resistance A water drop was dropped on the ink jet recording sheet of the present invention, and it was lightly rubbed with a hand, and sensory evaluation was carried out by the following method. ◯: No change was observed in the ink receiving layer. Δ: The ink receiving layer was partially removed. X: The ink receiving layer was completely removed.

The degree of bleeding in the solid printed portion of the ink bleeding green (overlapping portion of the two inks of cyan and yellow) was sensory-evaluated by the following method. ◯: Almost no ink bleeding was observed. B: Ink bleeding was observed. Poor: Ink bleeding was remarkable.

Transparency of the ink receiving layer The transparency of the ink receiving layer was visually evaluated by the following method after peeling off a part of the receiving layer. ◯: Completely transparent. Δ: A state in which there is some turbidity and inferior transparency. ×: Opaque.

Glossiness The glossiness after solid black printing is determined according to JIS-Z8741-1983.
The measurement was carried out at 75 degrees according to

[0055]

[Table 1]

[0056]

As is apparent from Table 1, the ink jet recording sheet obtained by the present invention has a transparent ink receiving layer and is excellent in glossiness, ink absorbency, water resistance and ink blur suitability. Is. The recording sheet of the present invention has a high transparency of the ink receiving layer, and can obtain high gloss before and after recording. In the present invention, a recorded image similar to a photograph can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the configuration of an inkjet recording sheet of the present invention.

[Explanation of symbols]

 1-Support 2-Receptor layer a (lower layer) 3-Receptor layer b (upper layer)

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Claims (3)

[Claims] 1. An ink jet recording sheet having a support provided with an ink receiving layer containing a water-soluble resin, wherein the ink receiving layer is composed of two or more layers, one of which is an upper layer. The water-insoluble rate is higher than that of the other layer (lower layer) on the support side, and the water-soluble resin contained in at least one layer of the ink receiving layer is at least selected from hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose and polyvinyl alcohol. One type of inkjet recording sheet. 2. The ink jet recording sheet according to claim 1, wherein the water-soluble resin contained in at least one layer of the ink receiving layer is at least one selected from hydroxypropylmethyl cellulose and hydroxypropyl cellulose. 3. The water insolubilization rate of the upper layer is 85% or more,
The ink jet recording sheet according to claim 1 or 2, wherein the water insolubilization rate of the lower layer is 0 to 60%.