JPH09156207A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a curl or adhesion.stickness before and after printing while keeping high glossiness and excellent ink absorbing characteristics by successively laminating a first hydrophilic binder layer and a second hydrophilic binder layer on a support. SOLUTION: A first hydrophilic binder layer consisting of one component selected from gelatin and a derivative thereof and one component selected from polyvinyl alcohol and a derivative thereof is formed on a support and, further, a second hydrophilic binder layer consisting of one component selected from gelatin and or a derivative and polyvinyl pyrrolidone is laminated and formed on the first hydrophilic binder layer. By this constitution, high glossiness and excellent ink absorbing characteristics can be kept and a high-grade image reduced in curl or adhesion.stickness before and after printing can be formed.

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 particularly, it is capable of forming a high quality image while maintaining excellent ink absorbability and glossiness, and further curling property and transportability. The present invention relates to an inkjet recording paper having improved

[0002]

2. Description of the Related Art The ink jet recording system is one in which minute droplets of ink are ejected by various operating principles and adhered to a recording sheet such as paper to record an image / character, but at a relatively high speed. It has advantages such as low noise and easy multicoloring. With respect to nozzle clogging and maintenance, which have been a problem with this system, improvements have been made from both the ink and device sides, and are now rapidly spreading to various fields such as various printers, facsimiles, and computer terminals. .

As a recording paper used in this ink jet recording system, the density of print dots is high, the color tone is bright and vivid, the ink is absorbed quickly, and the ink flows out even when the print dots overlap. It is required that the ink does not bleed, that the diffusion of the print dots in the lateral direction is not excessively large, and that the periphery is smooth and does not blur.

In order to solve these problems, for example, Japanese Patent Laid-Open No. 52-53012 discloses an ink jet recording paper obtained by wetting a low-sized base paper with a coating material for surface processing. Further, JP-A-55-5830 discloses an ink jet recording paper having an ink-absorptive coating layer on the surface of a support, and JP-A-55-51583 and JP-A-56-56.
No. 157 discloses an example using non-colloidal silica powder as a pigment in the coating layer.

However, in general, when the ink-receptive ink-receptive layer is composed only of a layer having many voids for absorbing and holding ink, the ink-receptive layer having many voids forms an interface with the air. Since the surface of the coating film has many micro irregularities, the incident light to the ink receiving layer is scattered and the transmission thereof is hindered, so that it becomes difficult to produce gloss and becomes opaque. Furthermore, since it is difficult for light to reach the ink that has penetrated into the voids, the image becomes whitish and the color reproducibility and color density are reduced. It has been difficult to obtain an image with high color reproducibility and color density while maintaining the property.

On the other hand, for the purpose of imparting gloss and other purposes, a hydrophilic binder such as gelatin or polyvinyl alcohol, which absorbs ink due to dissolution or swelling of the ink absorbing layer when the ink droplets land, is coated on the support. A large number of recording papers, films and the like have been conventionally known. Although these binders have high glossiness because they absorb ink due to dissolution or swelling, the ink absorbency and dryness are generally slower than in the case of using the voids,
Occurrence of stains and bleeding between colors due to ink transfer was likely to be a problem.

That is, when only the dissolution and swelling properties of only the hydrophilic binder are used, it is necessary to apply the necessary amount of the hydrophilic binder so that the ink can be instantaneously sufficiently retained for high quality recording. You will need it to get the image. It is known that when a considerable amount of the hydrophilic binder is applied to the support, it is preferable to use at least a part of the hydrophilic binder capable of reversible sol-gel conversion from the viewpoint of productivity and glossiness.

For example, in the example of JP-A-57-36692, an ink jet recording paper in which a coating solution containing gelatin as a part of a binder and a basic mordant as an ink receiving layer is coated on a base paper or a polyethylene terephthalate film support. JP-A-60-171143 describes an ink jet recording paper having a coating layer containing a water-soluble polymer having an ionic group.
No. 218180 describes an inkjet recording paper containing gelatin having a swelling degree in water of 30 to 60 times as an ink receiving layer, and a two-layer constitution is disclosed in the examples.

Further, Japanese Patent Application Laid-Open No. 2-1359 describes an ink jet recording paper in which a layer having an amino group inactivated gelatin derivative and a polyalkylene oxide is provided on a support, and Japanese Patent Application Laid-Open No. 6-64306 discloses. An ink jet recording paper obtained by coating an ink receiving layer containing gelatin on a support to form a gel, and then drying by a cold dry method is further disclosed in JP-A-1-146784. An inkjet recording paper provided with a layer containing a surfactant is described.

In the system in which the ink absorption due to the dissolution or swelling of the binder itself is adopted in the ink receiving layer, the diameter of the ink dot at the time of landing of the ink is controlled, the ink holding property, the ink drying property, or the ink bleeding, etc. It is also known that it is preferable to provide a plurality of ink receiving layers in order to independently control the various properties.

When a plurality of hydrophilic binder layers are coated on a support, it is necessary not to mix the layers between the layers in order to obtain a uniform coating film surface. It is also important to apply them at the same time in order to reduce the manufacturing cost. When applying such a plurality of hydrophilic binders, it is necessary to coat each support on the support and then to solidify by cooling (hereinafter referred to as a set) and then to dry it, in order to obtain uniform coating film surface and production efficiency. Is also known to be preferable.

By the way, in addition to using a hydrophilic binder capable of reversible sol-gel conversion, for example, JP-A-7-4064 is used.
No. 6 discloses an ink jet recording paper in which an ink absorbing layer is divided into an upper layer and a lower layer, polyvinyl alcohol is contained in the upper layer, and polyvinylpyrrolidone is contained in the lower layer. In the above patent, when used in the ink absorbing layer, polyvinylpyrrolidone has a problem that although the ink absorbing property is excellent, the spread of ink droplets is small, and the stickiness after recording tends to remain for a long time. Alcohol has relatively good ink absorbency in the monochromatic area, but has the drawback that the ink easily flows in the mixed color area, resulting in an unclear image. It is described that the above configuration is preferable in order to obtain excellent ink absorbency while maintaining glossiness.

However, although the recording sheets described in these patents have improved ink absorbability compared with the conventional ones, they cannot be said to be sufficient yet, and in particular, curling in a low humidity environment and under a high humidity environment. Problems such as stickiness and sticking when stacked were also left.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide curl before and after printing while having high gloss and excellent ink absorption characteristics. It is to provide an inkjet recording paper with little stickiness and stickiness.

A second object of the present invention is to provide an ink jet recording paper having high productivity in manufacturing the same.

[0016]

The above object of the present invention is achieved by the following constitution.

A first hydrophilic binder layer having at least one selected from gelatin and its derivatives and at least one selected from polyvinyl alcohol and its derivatives on a support, and at least selected from gelatin and its derivatives. An ink jet recording paper comprising one kind and a second hydrophilic binder layer having polyvinylpyrrolidone, which are laminated in this order.

That is, the present inventors have conducted extensive studies to achieve both excellent ink absorbency and high gloss, which are essential requirements for ink jet recording paper, and to reduce curling, sticking and stickiness before and after printing. , A support having a hydrophilic binder layer in which at least one selected from gelatin and its derivatives as a hydrophilic binder capable of reversibly sol-gel conversion, and polyvinylpyrrolidone showing high ink absorbability are used in combination as the outermost layer of the ink receiving layer. By providing a hydrophilic binder layer in combination with polyvinyl alcohols having an improved ink absorbability by providing the above, and also having an effect of excellent curling characteristics, if a hydrophilic binder layer is applied to a layer below the outermost layer, Curling, sticking and stickiness can be suppressed, and polyvinylpyrrolidone, gelatin and its derivative And which has led to finding the present invention can be excellent ink absorption properties and control the curl properties and good balance by setting the amount of addition of such as polyvinyl alcohol to an appropriate value.

Further, when the ink jet recording paper is manufactured, the coating liquid containing the hydrophilic binder capable of reversibly converting the sol-gel as described above is simultaneously coated on the support, so that it is set (cooled and solidified). Since a simple operation for drying is guaranteed, it also has an effect of being excellent in productivity and cost.

The present invention will be described in detail below.

The ink jet recording paper of the present invention comprises, on a support, a first hydrophilic binder layer having at least one selected from gelatin and its derivatives and at least one selected from polyvinyl alcohol and its derivatives. At least one selected from gelatin and its derivatives and a second hydrophilic binder layer containing polyvinylpyrrolidone are laminated in this order.

Examples of the gelatin include acid-treated gelatin and alkali-treated gelatin, but alkali-treated gelatin is preferable. As such alkali-processed gelatin, those widely known for photographic use can be appropriately used. As the gelatin derivative, amino group-inactivated gelatin obtained by reacting the amino group or imino group of gelatin with an isocyanate such as phenyl isocyanate or an acid anhydride such as phthalic anhydride is preferably used.

In the present invention, the gelatin derivative is particularly preferably amino group-inactivated gelatin from the viewpoint of the drying property of the ink after printing.

The first hydrophilic binder layer in the present invention has at least one selected from gelatin and its derivatives and at least one selected from polyvinyl alcohol and its derivatives. Those having an average degree of polymerization of 300 to 700, especially 400 to 600 are preferably used, and those having a saponification degree of 70% or more are preferable.

As the polyvinyl alcohol derivative,
It is possible to appropriately select and use one that has been used in the conventionally known inkjet recording paper. As such a polyvinyl alcohol derivative, for example, Japanese Patent Laid-Open Publication No.
1-10483, 61-27279, 61-1
Cation-modified polyvinyl alcohols described in JP-A-34291 and JP-A-6-143798, JP-A-6-155.
Examples thereof include acetoacetylated polyvinyl alcohol described in JP-A No. 895, vinylpyrrolidone-modified polyvinyl alcohol described in JP-A-6-55, and silyl-modified polyvinyl alcohol described in JP-A-7-101141.

At least one selected from polyvinyl alcohol and its derivatives is contained in a proportion of 50 to 300% by weight based on the total amount of at least one selected from gelatin and its derivatives contained in the first hydrophilic binder layer. Preferably. The amount of at least one selected from polyvinyl alcohol and its derivatives is 50
When the content is less than 10% by weight, good ink retention is difficult to obtain, and particularly when the ink contains 10 to 30% by weight of an organic solvent, the ink is deposited on the surface with time,
When the surface is rubbed with a finger, ink rub marks easily appear.
Further, the curl characteristic of the recording paper is deteriorated, and problems such as curling of the recording paper itself with the ink receiving layer under low humidity conditions or curl outward under high humidity conditions are likely to occur.
On the other hand, when the amount of polyvinyl alcohol exceeds 300% by weight, the set temperature of the coating solution is too low, and it becomes difficult to make use of the reversible sol-gel conversion property of gelatin.

In order to obtain good coatability, it is preferable that the degree of polymerization of polyvinyl alcohol or its derivative is 700 or less and the degree of saponification is 70% or more.

The second hydrophilic binder layer in the present invention has at least one selected from gelatin and its derivatives and polyvinylpyrrolidone, and the polyvinylvinylpyrrolidone has an average molecular weight of 10,000 to 40.
Thousands are preferably used. Polyvinylpyrrolidone retains good ink absorbability, but from the viewpoint of obtaining good transportability with few physical problems such as curling and sticking, gelatin contained in the second hydrophilic binder layer and At least 1 selected from its derivatives
It is preferably contained in a proportion of 30 to 200% by weight with respect to the total amount of seeds. If the proportion of polyvinylpyrrolidone is less than 30% by weight, it is difficult to obtain good ink absorbability, and 2
If it exceeds 100% by weight, the hygroscopicity of the film forming the second hydrophilic binder layer increases under high humidity conditions, and sticking and stickiness increase, which lowers the transportability and causes curling before and after recording. There is a problem in that it is easy to do, and further, the set temperature of the coating solution is lowered to cause a serious trouble in coating.

In the ink jet recording paper of the present invention, when considering the ink absorbency, the above various physical properties and the conditions of the coating liquid, 90% by weight or more of the total amount of the hydrophilic binder in the second hydrophilic binder layer is used. At least one selected from gelatin and its derivatives and polyvinylpyrrolidone are preferred.

It is preferable that the total weight of at least one selected from polyvinyl alcohol and its derivatives on the support is larger than the total weight of polyvinylpyrrolidone, from the viewpoint that good curling characteristics before and after printing of the ink jet recording paper can be maintained. .

On the contrary, when the amount of polyvinylpyrrolidone is large, the occurrence of curling under a low humidity condition or a high humidity condition may significantly increase.

Further, the ink jet recording paper of the present invention is
From the viewpoint of curling, it is preferable that the total amount of amino group-inactivated gelatin on the side of the ink absorbing layer on the support is 6 g or less per 1 m ^{2 of the} inkjet recording paper, and it is less than the total amount of polyvinyl alcohol. The average of the back surface of the hydrophilic binder layer is at least one selected from 50 to 100% by weight of gelatin and its derivatives with respect to the total amount of at least one selected from gelatin and its derivatives contained in the total hydrophilic binder layer. It is preferable to contain solid fine particles having a particle diameter of 2 to 20 μm.

A small amount of a hydrophilic binder other than those described above can be used in the first and second hydrophilic binder layers and the other hydrophilic binder layers constituting the hydrophilic binder.

Examples of such hydrophilic binders include, for example, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxylpropyl cellulose,
Dextran, dextran sulfate, dextrin, polyacrylic acid and its salts, agar, κ-carrageenan, λ
-Carrageenan, ι-carrageenan, xanthene gum,
Locust bean gum, alginic acid, casein, gum arabic, pullulan, polyethylene glycol (having a molecular weight of about 5,000 or more), water-soluble polyvinyl butyral, or vinyl monomers having a carboxyl group or a sulfonic acid group described in JP-A-62-245260. Examples thereof include polymers such as copolymers alone or having these vinyl monomers repeated.

In the ink jet recording paper of the present invention, at least the first and second hydrophilic binder layers are laminated in this order on the support, but another hydrophilic binder layer is appropriately provided on the ink receiving layer side. It may be provided,
For example, the other hydrophilic binder layers include the first and second hydrophilic binder layers.
May be laminated between the hydrophilic binder layers, and may be provided without particular limitation, provided that the hydrophilic binder layer farthest from the support, that is, the outermost layer is the second hydrophilic binder layer. There is.

For the other hydrophilic binder layer, it is preferable to use at least one selected from the above polyvinyl alcohol and its derivatives, gelatin and its derivatives.

In the ink jet recording paper of the present invention, from the viewpoint of curling prevention, the total amount of gelatin and gelatin derivatives is 20 to 50% by weight based on the total amount of hydrophilic binder on the ink jet recording surface side. It is preferable that the total amount is 20 to 80% by weight.

In producing the ink jet recording paper of the present invention, after coating the coating liquid constituting each of the hydrophilic binders, the temperature of the coating liquid is lowered by 5 ° C. or more and cooled to gel the coating liquid. It is preferable to use a method of drying after drying. At this time, it is preferable that all the hydrophilic binder layers on the ink recording side are coated at the same time from the viewpoints of reducing the manufacturing cost and obtaining high gloss.

When the second hydrophilic binder layer is laminated as the uppermost layer, that is, as a protective layer, its main purpose is to maintain the surface gloss and to provide a proper slipperiness and anti-sticking function. In the ink jet recording paper of the invention, its characteristics and constitution are particularly important. Therefore, a matting agent added when imparting a proper slipperiness or anti-sticking function, for example, an inorganic pigment that deteriorates gloss,
It is not preferable to add a large amount of organic fine particles, oil drops, or a highly hygroscopic material.

The inorganic pigment or organic fine particles added to the protective layer is approximately 1 with respect to the hydrophilic binder constituting the protective layer.
It is 0% by weight or less, preferably 2% by weight or less. Further, the oil droplets such as the emulsified dispersion added to the protective layer are approximately 50% by weight or less, preferably 20% by weight, with respect to the hydrophilic binder.
It is as follows.

As the inorganic pigment, one or more known white pigments can be used. For example, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide. , Zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate,
White inorganic pigments such as magnesium silicate, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, pseudo-boehmite, aluminum hydroxide, lithopone, zeolite, hydrohalloysite, magnesium hydroxide, etc., and styrene plastic as organic fine particles. Pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin, melamine resin and the like.

The dry coating amount of the hydrophilic binder in the ink jet recording paper of the present invention, that is, the coating solid content is not particularly limited, but is preferably about 5 to 60 g / m ² , and 1
0 to 40 g / m ² is more preferable. Note that, from the viewpoint of preventing curl after forming a recorded image, it is preferable to form the recording image as thin as possible.

The polycationic polyelectrolyte described in JP-A-56-84992 and JP-A-57-36692 are used as water-proofing agents for images in any of the constituent layers on the ink recording surface side of the present invention.
No. basic latex polymer, Tokiko 4-15744
No., JP-A-61-58788 and 62-174184.
No. 61-47290.
One or more of the alkali metal weak acid salts described in the above item can be used.

The content of the water-proofing agent is 1 to 40% by weight, particularly preferably 3% by weight based on the total solid content of the hydrophilic binder layer.
It is preferably ˜20% by weight.

Further, in the ink receiving layer of the present invention, if necessary, a UV absorber, an antioxidant, a dispersant, a fluorescent dye,
Various known additives such as a pH adjuster, a defoaming agent, a lubricant, an antiseptic, a surfactant, a thickener, a cross-linking agent and an antistatic agent may be contained.

The ink jet recording paper of the present invention preferably contains a surfactant in order to control the ink absorbency and the ink droplet diameter to an appropriate size. Above all, it is particularly preferable to use a cationic surfactant having a fluorine atom and an anionic surfactant having the same atom in combination. The cationic surfactant having a fluorine atom is 0.0 per 1 m ² of the inkjet recording paper.
The anionic surfactant contained in the range of 05 to 0.5 g, preferably 0.01 to 0.2 g, and having the same atom is 0.01 to 1 g per 1 m ² of the ink jet recording paper,
It is preferably contained in the range of 0.02 to 0.5 g. The anion- or cation-type surfactant having a fluorine atom is preferably added to the coating liquid for forming the protective layer, but may be added separately in other layers.

In the coating step for producing the ink jet recording paper of the present invention, a curtain coating method or an extrusion coating method using a hopper described in US Pat. No. 2,681,294 is preferably used. At this time, it is preferable from the viewpoint of productivity that the coating liquid set in the drying step is heated under the condition that the coating liquid does not dissolve again. Usually, after setting, after evaporating water to some extent within the range of room temperature to 30 ° C., it is heated to 40 ° C. to 50 ° C. and completely dried. The set temperature is generally determined by the set temperature of each coating solution, but it is generally performed by blowing cold air at about 0 ° C.

As the support, those conventionally known as ink jet recording papers can be appropriately used.

Examples of the transparent support include polyester resin, diacetate resin, triacetate resin,
Films and plates made of materials such as acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyimide resin, cellophane, celluloid, etc., and glass plates can be mentioned, and among them, when used as OHP, they withstand radiant heat. Those of the nature are preferable, and polyethylene terephthalate is particularly preferable. The thickness of such a transparent support is preferably about 10 to 200 μm.

The support used when it is not necessary to be transparent is, for example, ordinary paper, synthetic paper, resin-coated paper,
Examples thereof include sheets and plates made of cloth, wood, metal, and the like, and those obtained by subjecting the above translucent support to opaque treatment by known means. As the opaque support, a resin-coated paper (so-called RC paper) having a polyolefin resin-coated layer obtained by adding a white pigment or the like to at least one of the base paper, and a so-called white pet obtained by adding a white pigment to polyethylene terephthalate are preferable. For the purpose of increasing the adhesive strength between the support and the ink image-receiving layer, it is preferable to subject the support to corona discharge treatment, subbing treatment or the like prior to coating the ink-receiving layer. Further, the recording sheet of the present invention does not necessarily need to be colorless, and may be a colored recording sheet.

[0051]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. In the examples, "%" indicates absolutely dry weight% unless otherwise specified,
The added amount is the amount per 1 m ^{2 of} inkjet recording paper.

Example 1 (Preparation of inkjet recording sheets 1 to 10) 100 g /
Paper support with polyethylene coated on both sides of m ² base paper (thickness 140 μm, 7% by weight in polyethylene layer on recording side)
(Containing titanium dioxide) on the back side of the recording surface of 3.9 g / m ² of alkali-processed gelatin and 0.2 g of a back layer.
Ink jet recording paper 1 is prepared by coating and drying a coating solution of silica having an average particle diameter of about 3 μm on a support, and coating each layer having the following composition in the order of the first layer and the second layer.
10 were produced.

First layer: gelatin or gelatin derivative (listed in Table 1) 2.5 g Water-soluble polymer (listed in Table 1) 3.5 g Surfactant-1 0.012 g Second layer (protective layer): gelatin or Gelatin derivative (listed in Table 1) 1.0 g Water-soluble polymer (listed in Table 1) 1.0 g Surfactant-2 0.03 g Surfactant-3 0.11 g

[0054]

Embedded image

For coating, the coating solutions for the respective layers were simultaneously coated by the slide hopper method. Each coating solution was superposed on the support, cooled and set at about 0 to 5 ° C for about 20 seconds, and then rapidly dried with a wind in the range of 20 to 50 ° C.

[0056]

[Table 1]

Alkali-treated G = Alkali-treated gelatin PC-G: Phenylcarbamoylated gelatin PVP: Polyvinylpyrrolidone (average molecular weight = about 36)
10,000) PVA: polyvinyl alcohol (average degree of polymerization = about 40)
0, saponification degree = 90%) HEC: hydroxylethyl cellulose PAA: polyacrylic acid STMA: styrene / maleic acid copolymer DX: dextrin (preparation of inkjet recording paper 11) Further, in inkjet recording paper 2, the first layer PC- G for PVA
Then, an inkjet recording paper 11 in which the second layer PC-G was replaced with PVP was prepared by the following procedure.

The first layer was coated on the support with a wire bar and then dried. After drying, the coating solution for the second layer was similarly coated and dried with a wire bar.

(Preparation of inkjet recording paper 12)
In addition, in the inkjet recording paper 2, the first layer and the second layer
The inkjet recording paper 12 in which the water-soluble polymer of each layer is replaced with PC-G is used as the inkjet recording paper 2.
It was produced in the same manner as described above.

Next, using the obtained ink jet recording paper, the following items were evaluated by printing an evaluation pattern using an ink jet printer BJC-600S manufactured by Canon Inc. as follows.

<Evaluation> (Ink Absorption) A recording paper on which three colors of yellow, magenta, and cyan were recorded was stored at room temperature (20 ° C., 50% R.C.).
H. ) For 20 seconds, and then the back surface of another ink jet recording paper is superposed on the recorded image surface and a load of 5 g per 10 cm ² is applied and held for 30 seconds. Was decided.

○ When not attached at all △ When attached in a trace state × When clearly attached

(Blur of Heavy Color) Blurring was judged in the boundary area on the image surface in which a line of cyan ink (width of about 1 mm) was drawn on the background of a single color of magenta ink.

Bleeding rate in the boundary area is about 10% or less. △ Bleeding rate in the boundary area is about 30% or less.

(Glossy) After printing, the product was stored for one day and night and completely dried, and then the surface glossiness was measured by a variable angle gloss meter (VGS-1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.).

(Stick) An unrecorded ink jet recording sheet was printed at 40 ° C. and 80% R.A. H. After conditioning the humidity for 24 hours,
10 pieces each, 50 per 100 cm ²
The sample was stored under a weight of 0 g for another 24 hours. After storage, sticking between the recording surface and the back surface was evaluated according to the following criteria.

○ No trace of sticking △ A slight trace is recognized, but the trace area remains below about 10% × 10% or more.

(Curl) 23 ° C., 20% R.O. H. And 2
3 ° C, 80% R.S. H. Left for 48 hours in
The curl heights of the four corners having a size of 10 cm × 10 cm were measured. The curl on the ink receiving layer side is "+", and the curl on the back surface side is "-", and the unit is expressed in mm.

Table 2 shows the results of the above evaluation items.

[0070]

[Table 2]

As is clear from the results of Table 2, the ink jet recording papers 1 to 3 of the present invention have good ink absorbency,
It can be seen that it has heavy color bleeding, curl performance, glossiness and sticking performance. Among them, it can be seen that the inkjet recording paper 2 using phenylcarbamoyl gelatin as the gelatin derivative has the best characteristics.

On the other hand, it is understood that the comparative ink jet recording papers 4 and 10 use PVA for the second layer, that is, the protective layer, so that the ink absorbency is lowered. Further, the ink jet recording papers 5 and 6 using a hydrophilic binder other than polyvinylpyrrolidone for the protective layer have good ink absorbency, but have deteriorated curling characteristics and sticking. Further, although PVP is used for the protective layer, it can be seen that curl characteristics and sticking are also poor when a hydrophilic polymer other than PVA is used together with phenylcarbamoyl gelatin for the first layer.

On the other hand, although the ink jet recording paper 11 which does not use gelatin or its derivative at all has very good ink absorbency, not only does it need to be applied twice, but also sticking and curling properties are deteriorated. You can see that Further, it is understood that good ink absorbency cannot be obtained with the inkjet recording paper 12 using only the gelatin derivative.

Example 2 Table 3 shows the amounts of phenylcarbamoyl gelatin and polyvinyl alcohol contained in the first layer of the ink jet recording paper 2 prepared in Example 1, and the amounts of phenylcarbamoyl gelatin and polyvinylpyrrolidone contained in the second layer. Various changes were made as shown, and ink jet recording papers 21 to 28 were manufactured in the same manner as in Example 1.

[0075]

[Table 3]

Each of the obtained ink jet recording sheets was evaluated in the same manner as in Example 1. Table 4 shows the results.

[0077]

[Table 4]

As is clear from the results shown in Table 4, when the amount of polyvinyl alcohol is small relative to the phenylcarbamoyl gelatin of the first layer, the ink absorbency tends to decrease. Further, it can be seen that the ink absorptivity is low even in the inkjet recording paper 24 in which the ratio of polyvinylpyrrolidone in the protective layer is small. On the other hand, it can be seen that the curl of the inkjet recording paper 26 in which the ratio of polyvinylpyrrolidone to phenylcarbamoyl gelatin is high is slightly deteriorated. Further, in the ink jet recording paper 28 in which the ratio of polyvinylpyrrolidone is higher than that of polyvinyl alcohol, sticking and curling are deteriorated.

[0079]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an ink jet recording paper which has notable curl, stickiness and stickiness before and after printing, while having high gloss and excellent ink absorption characteristics. . Further, the inkjet recording paper of the present invention can be obtained by a simple operation, and is suitable for manufacturing with high productivity.

Claims (10)

[Claims] 1. A first hydrophilic binder layer having at least one selected from gelatin and its derivatives and at least one selected from polyvinyl alcohol and its derivatives on a support, and selected from gelatin and its derivatives. At least one of the above and a second hydrophilic binder layer having polyvinylpyrrolidone are laminated in this order, and an ink jet recording paper. 2. The ink jet recording paper according to claim 1, wherein a total hydrophilic binder layer including the first and second hydrophilic binder layers is simultaneously coated on a support. 3. Polyvinylpyrrolidone in an amount of 30 to 200 relative to the total amount of at least one selected from gelatin and its derivatives contained in the second hydrophilic binder layer.
The ink jet recording paper according to claim 1, wherein the ink jet recording paper is contained in a weight percentage. 4. The method according to claim 1, wherein 90% by weight or more of the total amount of the hydrophilic binder in the second hydrophilic binder layer is at least one selected from gelatin and its derivatives and polyvinylpyrrolidone. 4. The inkjet recording paper according to any one of 3 above. 5. 50 to 300% by weight of at least one selected from polyvinyl alcohol and its derivatives is contained with respect to the total amount of at least one selected from gelatin and its derivatives contained in the first hydrophilic binder layer. The inkjet recording paper according to any one of claims 1 to 4, wherein 6. The polymerization degree of at least one selected from the polyvinyl alcohol and its derivatives is 700 or less, and the saponification degree is 70% or more, in any one of claims 1 to 5. The inkjet recording paper described. 7. The inkjet recording paper according to claim 1, wherein at least one selected from the gelatin and its derivatives is an amino group inactivated gelatin derivative. 8. The total amount of the amino group-inactivated gelatin derivative is 6 g or less per 1 m ^{2 of the} inkjet recording paper, and is less than the total weight of at least one selected from polyvinyl alcohol and its derivatives. Item 7. The inkjet recording paper according to item 7. 9. The inkjet according to claim 1, wherein the total weight of at least one selected from polyvinyl alcohol and its derivatives on the support is larger than the total weight of polyvinylpyrrolidone. Recording sheet. 10. The back side of the hydrophilic binder layer on the support is 50 to 100% by weight of gelatin based on the total amount of at least one selected from gelatin and derivatives thereof contained in the total hydrophilic binder layer. 10. At least one selected from the derivatives and solid fine particles having an average particle diameter of 2 to 20 μm are contained.
The ink jet recording paper according to any one of the above.