JP2002326451A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet in which an image of a high quality level can be printed in an ink jet recording system such as an ink jet printer, a plotter or the like and which has a high strength of a coating film and excellent water resistance of the film. SOLUTION: The ink jet recording sheet comprises a support made of a resin film, an undercoating layer and an ink acceptive layer provided on the support. In this sheet, the undercoating layer contains a water insoluble resin, and the ink acceptive layer contains a synthetic amorphous silica, a water soluble resin and a nonionic water insoluble resin as binding agents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more particularly to an ink jet recording sheet used for image recording and printing printers using an aqueous ink.

[0002]

2. Description of the Related Art A sharp image and excellent print quality can be obtained by improving the performance of an ink jet system, particularly, by improving the printing speed, resolution, saturation, etc., and in particular, by the technical progress of an ink jet color printer for producing a color hard copy at a high speed. It has become possible. On the other hand, in order to further improve the print quality, saturation, appearance, and image, a recording material having higher characteristics has been required. In particular, due to improvements in printing speed, resolution, saturation, etc., more advanced properties such as quick drying of ink, high absorption capacity, control of dot diameter and bleeding are required for recording materials, and ink receiving Various recording sheets having a layer on the surface have been developed.

[0003] For example, JP-A-56-148584 discloses a porous inorganic pigment having a function of adsorbing and retaining a dye on the surface of a support (natural zeolite, synthetic zeolite,
It is disclosed to provide an ink receiving layer containing diatomaceous earth, fine silicic acid, synthetic mica) particles. JP-A-58-
Japanese Unexamined Patent Publication No. 7-67852 discloses that the ink receiving layer contains a weak acid salt of a divalent metal in JP-A-94491 and that the ink receiving layer contains a quaternary ammonium salt substance in JP-A-6-234268. The publication discloses that fluorine is contained in the pigment of the ink receiving layer. However, such an ink jet recording sheet has a drawback that the paper is torn by water because the paper made of a highly water-absorbing pulp as a main material is used for the support.
Even when water-resistant paper is used, problems such as elongation, wrinkling and curling occur, and there is a problem in water resistance in practical use. On the other hand, when a resin film having excellent water resistance is used as a support, when an ink receiving layer is provided on the support by a conventional method, the paper surface wet with water droplets or the like is rubbed with a finger or a pen or the like. Insufficient water resistance of the coating film occurs such that the ink receiving layer is peeled off from the body and the interface. As inkjet paper with a multilayer structure,
JP-A-1-225585, JP-A-5-05147
No. 0, etc., but all of the layers were ink holding layers or ink receiving layers, and the coating films did not have water resistance.

Further, in recent years, there has been a tendency to increase the amount of ink discharged from an ink jet printer in order to improve the print density. In the case of ink jet recording paper based on a resin film which does not absorb water, the ink is absorbed by a coating layer. Only because the substrate does not absorb the ink at all, bleeding due to insufficient ink absorption capacity is a problem. As described above, various proposals have been made for an ink jet recording sheet, but the ink absorption is still good,
There is no ink jet recording sheet excellent in printing density, coating strength and coating water resistance.

[0005]

SUMMARY OF THE INVENTION According to the present invention, high-quality images can be printed at high speed in an ink jet recording system such as an ink jet printer or plotter, and the coating film has high strength and excellent water resistance. Provided is a sheet for inkjet recording. Provided is an ink jet recording sheet having a high ink absorption speed, a small ink bleeding, a vivid coloration of the ink, a strong coating film, and excellent water resistance of the coating film.

[0006]

The present invention includes the following aspects. [1] An ink jet recording sheet comprising an undercoat layer and an ink receiving layer provided on a support made of a resin film, wherein the undercoat layer contains a water-insoluble resin, and the ink receiving layer is a synthetic amorphous silica. Further, an ink jet recording sheet containing a water-soluble resin and a nonionic water-insoluble resin as a binder. [2] The ink jet recording sheet according to [1], wherein the water-insoluble resin contained in the ink receiving layer contains at least one selected from vinyl acetate polymers. [3] The method according to [1] or [2], wherein the content of the water-insoluble resin in the total solid content of the binder contained in the ink receiving layer is from 20% by weight to 80% by weight. Sheet for inkjet recording. [4] The binder [1], [2] or [3], wherein the binder contained in the ink receiving layer is contained in an amount of 30 to 100 parts by weight based on 100 parts by weight of the synthetic amorphous silica. ] The sheet for inkjet recording as described above. [5] The ink receiving layer contains a water-soluble cationic resin [1], [2], [3] or [4].
The sheet for inkjet recording according to the above. [6] The undercoat layer has a water repellency based on JIS P-8137 of R6 or more [1] to [6].
The sheet for inkjet recording according to any one of [5].

[7] The water-soluble resin in the ink receiving layer contains partially saponified polyvinyl alcohol [1] to [6]
The inkjet recording sheet according to any one of the above. [8] The ink jet recording sheet according to [7], wherein the partially saponified polyvinyl alcohol contained in the ink receiving layer has a saponification degree of 90% or less.

[9] The content of [7] or [8], wherein the content ratio of the water-insoluble resin contained in the ink receiving layer is from 25 parts by weight to 200 parts by weight based on 100 parts by weight of the partially saponified polyvinyl alcohol. Sheet for inkjet recording. [10] The undercoat layer contains a pigment [1] to

The inkjet recording sheet according to any one of [9].

[0008] In the present invention, the reason for the ink absorption, color development,
Although it is not always clear whether a recording sheet having good bleeding, good coating strength and good coating water resistance can be obtained, it can be estimated as follows.

When a resin film is used as a support and an ink receiving layer is directly provided, a water-soluble resin is used as a binder for the ink receiving layer due to the properties of the ink receiving layer that requires high water absorption. However, when the recording sheet is wet with water, water penetrates from the coated surface or the recording sheet cross section, the adhesion between the ink receiving layer itself or the interlayer between the support and the ink receiving layer is impaired, and the coating film has good water resistance. Cannot be obtained. Further, when a water-insoluble resin is added to the ink receiving layer to improve the water resistance of the coating film, the water resistance of the ink receiving layer itself is improved with a small amount, but the ink receiving layer and the support can be sufficiently adhered to each other. Since no binder is present, the required water resistance between the layers cannot be obtained. Also, when used in large quantities,
Although the water resistance is improved, a large amount of the water-insoluble resin is present in the ink receiving layer, so that the ink absorption capacity is reduced, the ink overflows from the ink receiving layer, and bleeding occurs in the printed portion.
Although bleeding tends to be improved by extremely increasing the coating amount, there is a possibility that a problem may occur in the coating film strength and coating stability, and the amount is not suitable for practical use. However, by providing an undercoat layer containing a water-insoluble resin as a main component, the adhesion between the support and the undercoat layer and the adhesion between the ink-receiving layer and the undercoat layer are improved, so that the water resistance between the layers is improved. You. Therefore, it is possible to use a water-insoluble resin in the ink receiving layer to such an extent that the absorption capacity of the ink is not impaired, the water resistance of the ink receiving layer itself and the water resistance between layers are improved, the coating film has good water resistance, and An inkjet recording sheet having good absorbability can be obtained.

In addition, by containing a water-soluble resin in the ink receiving layer, an ink receiving layer having good ink absorbency and excellent coating strength can be obtained. However, depending on the type of resin used, the ink may spread laterally on the surface of the ink receiving layer before the ink is absorbed into the resin, resulting in bleeding. However, in a preferred embodiment of the present invention, by incorporating a partially saponified polyvinyl alcohol as a water-soluble resin in the ink receiving layer, an ink jet having excellent bleeding, good film strength, and excellent water resistance of the film is provided. A recording sheet is obtained. This is presumably because partially saponified polyvinyl alcohol has high water absorbency and can adsorb the ink inside the resin before spreading the ink in the horizontal direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the resin film used for the support in the present invention include thermoplastic resins such as polyester resins and olefin resins. As the polyester resin, polyethylene terephthalate, polybutylene terephthalate, polycyclohexene terephthalate and the like, and as the olefin resin, polyethylene, polypropylene, ethylene-propylene copolymer,
Examples thereof include those composed of an ethylene-vinyl acetate copolymer or those composed mainly of these. In addition, one or more of these thermoplastic resins can be appropriately selected and used, and a mixture of polystyrene, an acrylate copolymer, or the like can be used as another thermoplastic resin.
A film formed by stretching these thermoplastic resins in the machine direction and / or the transverse direction can also be used. In addition, a film may be formed by mixing an inorganic fine powder into the thermoplastic resin, and the film may be formed into a paper-like layer by, for example, a uniaxial stretching treatment or a biaxial stretching treatment. In the present invention, using a multilayer film obtained by laminating a plurality of such films as a support, for example, a two- or three-layer film provided with a base material layer and a paper-like layer on both sides or one side, Alternatively, a three- to five-layer film having a surface layer formed on at least one surface of a paper-like layer may be used. Such a paper made of a thermoplastic resin in a paper-like layer is generally known as synthetic paper. The opacity of such a film is not particularly limited in the present invention. Further, these resin films have better water resistance than paper and the like, and are suitable as the support of the present invention.

By providing an undercoat layer containing a water-insoluble resin, it is possible to obtain an ink jet recording sheet having good adhesion between the support and the ink receiving layer and excellent water resistance of the coating film. Examples of the water-insoluble resin used in the undercoat layer include conjugated diene-based polymer latex such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer, and polymers or copolymers of acrylate and methacrylate. (Meth) acrylic polymer latex such as coalescable, vinyl polymer latex such as vinyl acetate polymer such as vinyl acetate polymer and vinyl acetate copolymer, or carboxyl group and cationic group of these various polymers And water-insoluble resins such as a modified polymer latex containing a functional group.

It is easy to obtain a (meth) acrylic polymer latex having good water resistance after film formation. If a (meth) acrylic polymer latex is used as the water-insoluble resin, the undercoat layer after coating and drying can be obtained. Is particularly preferred because of its high barrier property against water. The glass transition temperature of the water-insoluble resin is preferably 50 ° C. or lower, more preferably 30 ° C. or lower. Although there is no lower limit on the glass transition temperature, for example, -70 ° C
Can also be used. This improves the adhesion between the support sheet such as polyolefin and the ink receiving layer. These water-insoluble resins are usually used in a dry weight range of preferably 10 to 100% by weight, more preferably 20 to 80% by weight, based on the solid content of the undercoat layer paint. These water-insoluble resins can be used in combination of two or more as necessary.

The undercoat layer of the present invention contains a water-insoluble resin as a main component, but pigments can be used within a range where the quality is not impaired in order to improve the coating suitability of the paint. Pigments that can be used in the undercoat layer include calcium carbonate, clay, calcined clay, diatomaceous earth, talc, aluminum oxide, silica, white carbon, magnesium aluminosilicate, magnesium carbonate, barium sulfate, titanium oxide, zinc oxide, Examples thereof include substances such as aluminum hydroxide, magnesium hydroxide, and organic pigments (plastic pigments). These pigments can be used in combination of two or more as necessary.

A water-soluble resin may be appropriately added to the undercoat layer of the present invention as long as the water resistance and the strength of the coating film are not impaired. Thereby, pigment dispersibility and coating suitability can be improved.
Examples of the water-soluble resin contained in the undercoat layer include polyvinyl alcohol and polyvinyl alcohol derivatives, proteins such as casein, and derivatives such as starch and oxidized starch. One or more of these water-soluble resins can be appropriately selected and used as necessary. In addition, pigment dispersants, defoamers,
Viscosity modifiers, cross-linking agents and the like are appropriately used depending on the production conditions and required performance.

The J of the undercoat layer used in the present invention
It is preferable that the water repellency based on the method described in ISP 8137 be R6 or more (R6 to R10), since an undercoat layer having more excellent coating water resistance can be obtained. The method for providing the undercoat layer on the support is not particularly limited, and it can be provided by a conventionally known coating machine such as a bar coater, an air knife coater, a blade coater, and a curtain coater. The coating amount of the undercoat layer obtained in the present invention is determined by the final use, and need not be unnecessarily increased as long as the coating film water resistance, recording characteristics, storage stability and the like are satisfied. 0 g / m ² is preferred.
5 to 8.0 g / m ² is more preferable. If the coating amount of the undercoat layer is small, the adhesion to the support and the water resistance of the coating film may not always be sufficient, and if the coating amount of the undercoat layer is large, the coating on the undercoat layer may be insufficient. Fine spherical substances (bubbles) are generated on the surface of the engineered ink receiving layer, which may impair the appearance of the recording paper.

As a pigment used in the ink receiving layer of the present invention, a method of mixing high-purity silica sand with sodium silicate and sulfuric acid to form a silicate sol, forming the silicate sol into a three-dimensional aggregate, temperature, ions, It is possible to use a synthetic amorphous silica obtained by a method of stopping the growth of secondary aggregates under the influence of a surfactant and causing sedimentation, or a method of decomposing silicon tetrachloride. By using these synthetic amorphous silicas for the ink receiving layer, it is possible to obtain a recording sheet having more excellent color developing properties of the ink. The particle diameter of these amorphous synthetic silicas is preferably 20 μm or less, more preferably 12 μm or less. By using amorphous silica having such a particle diameter, it is possible to obtain an image with good roundness of ink dots.

The water-soluble resin used in the ink receiving layer of the present invention has, for example, a large number of hydroxyl groups in the molecule, and therefore has good affinity with synthetic amorphous silica having hydroxyl groups on the surface. Since a hydrogen bond exists between the two types of hydroxyl groups, the strength of the coating film after drying the paint becomes good. Further, since the water-soluble resin absorbs the ink, it is possible to obtain an ink receiving layer having good ink absorbency, bleeding and coating strength. Examples of the water-soluble resin used in the ink receiving layer of the present invention include polyvinyl alcohol and cationic polyvinyl alcohol, polyvinyl alcohol derivatives such as silanol-modified polyvinyl alcohol, proteins such as casein,
Derivatives such as starch and oxidized starch are used. One or more of these water-soluble resins can be appropriately selected and used.

In a preferred embodiment of the present invention, partially saponified polyvinyl alcohol is used as the water-soluble resin for the ink receiving layer. This makes it possible to obtain an ink jet recording sheet that is more excellent in the effect of preventing bleeding. Polyvinyl alcohol is produced by saponifying polyvinyl acetate with an alkali. At this time, a polyvinyl alcohol in which all acetyl groups of the polyvinyl acetate are substituted with hydroxyl groups is a completely saponified polyvinyl alcohol, and a polyvinyl alcohol having a degree of saponification of about 98% to 99% is generally called a completely saponified polyvinyl alcohol. On the other hand, in a preferred embodiment of the present invention, a partially saponified polyvinyl alcohol other than the above, that is, a partially saponified polyvinyl alcohol is selectively used. It is not clear why partially saponified polyvinyl alcohol is good for bleeding, but it is presumed as follows. Fully saponified polyvinyl alcohol is a substance in which almost all acetyl groups in a polyvinyl acetate molecule are substituted with hydroxyl groups, and strong hydrogen bonds between hydroxyl groups are present in a large amount in the substance. In addition, it is presumed that the presence of these hydroxyl groups causes the water-soluble resin to absorb moisture in the molecule. But,
When the ink containing a large amount of water lands on the ink receiving layer containing the completely saponified polyvinyl alcohol, the water molecules in the ink try to enter between the hydrogen bonds in the completely saponified polyvinyl alcohol. Since the hydrogen bonds in the inside are strong, it takes a long time for water molecules to penetrate between the hydrogen bonds in the completely saponified polyvinyl alcohol and to be adsorbed on the ink receiving layer. Therefore, it is presumed that the ink is pulled by the hydroxyl groups on the resin surface before being absorbed into the molecule and spreads in the horizontal direction, and as a result, the bleeding is relatively deteriorated. However, in partially saponified polyvinyl alcohol, acetyl groups are randomly present in the molecule, and steric hindrance of the acetyl group partially inhibits hydrogen bonds between hydroxyl groups in the molecule, resulting in weak hydrogen bonds in the molecule. In addition, the water absorption is improved. Therefore, when the ink containing a large amount of water lands on the ink receiving layer containing partially saponified polyvinyl alcohol, the ink is quickly adsorbed to the ink receiving layer where the partially saponified polyvinyl alcohol is present, and is absorbed in the vertical direction after the adsorption. Occurs preferentially,
A recording sheet with good bleeding can be obtained. The above-described ink absorption mechanism shows the concept when the ink lands on the surface of the receptor layer and the ink dissolves and is adsorbed on the surface of the receptor layer, which is different from the so-called ink absorbency that absorbs all the ink.

In the present invention, it is more preferable to use partially saponified polyvinyl alcohol having a saponification degree of 90% or less. On the other hand, there is no lower limit to the degree of saponification, but if the degree of saponification is low, the solubility in water is reduced, so the addition of alcohols is required in the preparation of the paint, which may be disadvantageous in terms of safety and ease of handling. The degree of saponification of partially saponified polyvinyl alcohol is more preferably at least 65%, even more preferably at least 70%.

The degree of polymerization of the partially saponified polyvinyl alcohol used in the ink receiving layer of the present invention is not particularly limited, but the printing degree and the water resistance of the coating film tend to be better than 200 in terms of print quality and water resistance. However, the degree of polymerization is 500
If it exceeds 0, the viscosity of the coating composition tends to be high and the coating tends to be difficult. Further, when the degree of polymerization is less than 200, the water resistance of the receiving layer may be deteriorated when the recording sheet is used. For the above reasons, the polymerization degree is preferably 200 or more and 5000 or less.

In the present embodiment, another water-soluble resin may be added to the ink-receiving layer in order not to impair the bleeding of the ink in order to improve the pigment dispersibility and the coating suitability. Examples of such water-soluble resins include cations, modified polyvinyl alcohols such as silanol, proteins such as casein, starch, and oxidized starch.

As described above, in the present invention, by including a water-insoluble resin in the ink receiving layer, it is possible to obtain an ink receiving layer having good water resistance of the ink receiving layer and excellent water resistance between the undercoat layer and the ink receiving layer. Can be. As the water-insoluble resin used in the ink receiving layer of the present invention, styrene-butadiene copolymer, conjugated diene-based polymer latex such as methyl methacrylate-butadiene copolymer, a polymer of acrylate and methacrylate, or Water-insoluble resins such as (meth) acrylic polymer latex such as copolymer and vinyl polymer latex such as vinyl acetate polymer (vinyl acetate polymer and vinyl acetate copolymer) can be exemplified. As the water-insoluble resin, a (meth) acrylic polymer latex and a vinyl acetate polymer latex are preferable because they have excellent weather resistance after coating and suppress yellowing of the ink receiving layer. The present invention uses a nonionic water-insoluble resin among them. The use of a nonionic water-insoluble resin has good adsorbability of the ink to the receptor layer and does not easily cause bleeding over time.

The addition ratio of the binder in the ink receiving layer to 100 parts by weight of the synthetic amorphous silica is not particularly limited.
It is preferable that the amount be not less than 100 parts by weight and not more than 100 parts by weight. When the addition ratio is low, the surface strength of the obtained ink receiving layer may be reduced. If the addition ratio is high, the ink absorption speed becomes slow, and it may take time to dry the ink.

It is preferable that the content ratio of the water-insoluble resin in the total solid content of the binder contained in the ink receiving layer is from 20% by weight to 80% by weight. When the content ratio is small, the amount of the water-soluble resin in the ink receiving layer increases, and the water resistance of the coating film may be reduced. When the content ratio is high, the water resistance of the coating film is improved, but bleeding may occur due to insufficient ink absorption capacity.

In the preferred embodiment of the present invention in which the ink receiving layer contains partially saponified polyvinyl alcohol and a water-insoluble resin, the water-insoluble resin is contained in an amount of 30 to 200 parts by weight based on 100 parts by weight of the partially saponified polyvinyl alcohol. It is preferable to be contained. When the content of the water-insoluble resin is small, the amount of partially saponified polyvinyl alcohol in the ink receiving layer increases, and the water resistance of the coating film may be reduced. Further, when the content of the water-insoluble resin is large,
Although the water resistance of the coating film is improved, bleeding may occur due to insufficient ink absorption capacity.

When the ink receiving layer of the present invention contains a water-soluble cationic resin, the color developing properties of the ink can be further improved. As the water-soluble cationic resin used in the ink receiving layer of the present invention, polyethyleneimine, polyvinylpyridine, polydialkylaminoethyl methacrylate, polydialkylaminoethyl acrylate, polydialkylaminoethyl methacrylamide, polydialkylaminoethyl acrylamide, polyepoxy Compounds such as amine, polyamidoamine, dicyandiamide-formalin condensate, dicyandiamide polyalkyl-polyalkylenepolyamine condensate, polydimethyldiallylammonium chloride, polyvinylamine, polyallylamine and the like, and modified products thereof can be exemplified. The amount of the water-soluble cationic resin is 1 to the total solid content of the water-soluble resin.
% To 50% is preferred. If the amount of the water-soluble cationic resin is small, the effect of improving the sharpness of printing may not be sufficiently obtained.On the contrary, although the color developing property of the ink is improved even if the amount is large, the water-soluble cationic resin is used as an adhesive. Some of the effects are low, and a desired coating film strength may not be obtained.

Other additives include a pigment dispersant, an antifoaming agent, a coloring agent, an antioxidant, an ultraviolet absorber, a viscosity modifier,
A cross-linking agent or the like is appropriately used according to the manufacturing conditions, printing quality, and required performance.

Known coating equipment such as a bar coater, an air knife coater, a blade coater, and a gravure coater is applied for coating the paint. The sheet provided with the ink receiving layer on the support can be used as it is as the recording sheet of the present invention. For example, the sheet can be treated with a super calender, a gloss calender or the like to impart surface smoothness. . The coating amount of the ink receiving layer obtained in the present invention is determined by the final use and is not particularly limited, but need not be unnecessarily large as long as the ink absorbency, color development, and coating film strength are satisfied. 30 g / m ² ,
Preferably, it is appropriately selected and used from the range of 5 to ²⁰ g / m ² . If the ink receiving layer is small, the ink absorption capacity is insufficient in many cases, the image flows out, the color bleeds, the image is blurred, the drying is slow, the ink adheres to the discharge roll of the printer, There is a risk of getting dirty. However, since the ink receiving layer is thick at most, the adhesiveness to the undercoat is weakened, and the peeled-off ink receiving layer may cause a problem such as clogging of the head nozzle, which is also expensive. Becomes

[0030]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but it should be understood that the present invention is not limited by these examples. In the following, parts and% all indicate parts by weight and% by weight.

Comparative Example I-1 Synthetic paper (trade name: Yupo FPG-110, manufactured by Oji Yuka Synthetic Paper) having a three-layer structure containing polypropylene and an inorganic pigment and having a central substrate layer and paper-like layers on both front and back surfaces , Thickness 110μm)
Is coated with 2 g / m ^{2 of the} UC layer paint I-1 on a single side using a bar coater and dried to form an undercoat layer. On top of this, the ink receiving layer paint I-1 is 15 g on a dry basis.
/ M ^{2 was} applied and dried to produce an ink jet recording sheet. “UC layer paint I-1” Calcium carbonate (trade name: Callite SA, manufactured by Shiroishi Central Research Institute) 100 parts, water-insoluble resin SBR latex (trade name: 0589, Tg = 0 ° C, manufactured by Nippon Synthetic Rubber)
100 parts “Ink-receiving layer coating material I-1” 100 parts synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia) 70 parts, water-insoluble resin, anionic acrylic polymer latex (trade name: Apretan 760H, Hoechst Synthetic) 40 parts

Comparative Example I-2 One side of a polyethylene terephthalate (PET) resin film (trade name: Lumirror T, manufactured by Toray Industries, Inc., thickness: 75 μm) was coated with a UC layer paint I-2 in an absolutely dry amount using a bar coater.
After coating 5 g / m ^2, drying was performed to provide an undercoat layer, and 30 g of the ink receiving layer coating material I-2 was dried on the undercoat layer.
/ M ² was applied and dried to produce an inkjet recording sheet. “UC layer paint I-2” Synthetic amorphous silica (trade name: Mizukasil P-603, particle size = 2.2 μm, manufactured by Mizusawa Chemical) 100 parts, water-insoluble resin acrylic polymer latex (trade name: Iodozol AD) −36, Tg = 20 ° C., manufactured by Kanebo NSC) 5
0 parts “Ink receiving layer paint I-2” synthetic amorphous silica (trade name: Fine Seal X-37,
Particle size = 2.5 μm, manufactured by Tokuyama) 100 parts, water-soluble resin polyvinyl alcohol (trade name: PVA-11)
7, made by Kuraray, saponification degree 98%, average polymerization degree 1700)
45 parts, water-insoluble resin anionic SBR latex (trade name: LACSTAR2800A, manufactured by Dainippon Ink and Chemicals) 5 parts

Example I-1 One side of the synthetic paper YUPO FPG-110 used in Comparative Example I-1 was coated with a UC layer paint I-3 on a single side using a bar coater in an absolutely dry amount of 15%.
g / m ² coating and drying to provide an undercoat layer,
On top of this, an ink-receiving layer coating material I-3 was dried in an absolutely dry amount of 30 g / m.
^Two coatings and drying were performed to produce an inkjet recording sheet. "UC layer paint I-3" 100 parts of zinc oxide (trade name: Zinhua No. 1, manufactured by Kasho)
Water-insoluble resin Acrylic polymer latex (trade name:
Resin 125-2211, Tg = 23 ° C, Kanebo NS
C) 120 parts “Ink receiving layer paint I-3” Synthetic amorphous silica (trade name: Fine Seal X-37,
Particle size = 2.5 μm, manufactured by Tokuyama 100 parts, water-soluble resin oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch) 16 parts, water-insoluble resin Nonionic vinyl acetate polymer latex (trade name: Iodosol CD-)
5, Kanebo NSC) 64 parts

Comparative Example I-3 5 g of UC layer coating material I-1 was used on one side of synthetic paper YUPO FPG-110 used in Comparative Example I-1 using a bar coater.
/ M ² coating and drying to provide an undercoat layer, on which the ink receiving layer coating material I-4 was dried at an absolutely dry amount of 20 g / m ^2.
Coating and drying were performed to produce an inkjet recording sheet. "Ink receiving layer coating material I-4" Synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia) 100 parts, water-soluble resin polyvinyl alcohol (trade name: Denka Povar K-17) 20 parts, water-insoluble resin, cationic acrylic copolymer latex (trade name: Iodosol AF943, manufactured by Denki Kagaku Kogyo Co., Ltd., 98% saponification degree, average polymerization degree 1700)
Kanebo NSC) 5 parts

Example I-2 5 g of a UC layer paint I-3 was applied on one side of a synthetic paper YUPO FPG-110 used in Comparative Example I-1 using a bar coater in an absolutely dry amount.
/ M ² coating and drying to provide an undercoat layer, on which an ink-receiving layer coating material I-5 was applied in an absolutely dry amount of 20 g / m ^2.
Coating and drying were performed to produce an inkjet recording sheet. "Ink receiving layer coating material I-5" Synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia) 100 parts, water-soluble resin polyvinyl alcohol (trade name: Denka Povar K-17) Manufactured by Denki Kagaku Kogyo Co., Ltd., saponification degree 98%, average polymerization degree 1700) 25 parts, water-insoluble resin, nonionic vinyl acetate polymer latex (trade name: Iodosol CD-5,
10 parts of Kanebo NSC, 8 parts of water-soluble cationic resin (trade name: PAS-H-5L, manufactured by Nitto Bo)

Comparative Example I-4 A UC layer paint I-4 was applied on one side of a synthetic paper YUPO FPG-110 used in Comparative Example I-1 using a bar coater in an absolutely dry amount of 5 g.
/ M ² after coating, drying was performed to provide an undercoat layer, and the ink receiving layer coating material I-1 was absolutely dried at 15 g / m ² on the undercoat layer.
Coating and drying were performed to produce an inkjet recording sheet. "UC layer paint I-5" 100 parts of calcium carbonate (trade name: Callite SA, manufactured by Shiroishi Central Research Institute), water-insoluble resin vinyl acetate / acrylic copolymer latex (trade name: Resin 125-11)
40, Tg = −20 ° C., manufactured by Kanebo NSC) 500
Part, water-soluble resin polyvinyl alcohol (trade name: PVA
-117, Kuraray) 40 parts

Comparative Example I-5 Using a bar coater on one side of the PET film used in Comparative Example I-2, 30 g of the ink-receiving layer coating material I-2 was absolutely dried.
/ M ² and dried to produce an inkjet recording sheet.

Comparative Example I-6 The synthetic paper FPG-110 used in Comparative Example I-1 was coated on one side with a bar coater using an ink-receiving layer coating material I-6 at an absolutely dry amount of 10 g / m ² and dried. Was performed to produce an inkjet recording sheet. “Ink receiving layer paint I-6” Synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia) 100 parts, water-soluble resin polyvinyl alcohol (trade name: Denka Povar K-17) 25 parts, water-insoluble resin, cationic acrylic copolymer latex (trade name: Iodosol AF943, manufactured by Denki Kagaku Kogyo Co., Ltd.,
Kanebo NSC) 25 parts

Comparative Example I-7 The synthetic paper FPG-110 used in Comparative Example I-1 was coated on one side with a bar coater, and the UC layer coating material I-1 was dried at 5 g / b.
m ^{2 was} applied, an undercoat layer was provided, and an ink-receiving layer coating material I-7 was applied thereon in an absolutely dry amount of 10 g / m ² ,
An ink jet recording sheet was manufactured. “Ink receiving layer paint I-7” 100 parts of synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia), water-insoluble resin, cationic acrylic polymer latex (trade name: (Iodozol AF943, manufactured by Kanebo NSC) 10
0 copies

Comparative Example I-8 A UC layer coating material I-3 was applied on one side of the PET film used in Comparative Example I-2 using a bar coater at a dry weight of 8 g / m ^2.
This was applied, an undercoat layer was provided, and an ink-receiving layer coating material I-8 was applied thereon in an absolutely dry amount of 15 g / m ² to produce an ink jet recording sheet. "Ink receiving layer paint I-8" Synthetic amorphous silica (trade name: Sylysia # 450, particle size = 5.2 μm, manufactured by Fuji Silysia) 100 parts, water-soluble resin polyvinyl alcohol (trade name: PVA-11)
7, made by Kuraray, saponification degree 98%, average polymerization degree 1700)
The following evaluation was performed for each of the coated sheet samples obtained in 40 parts, and the results are shown in Table 1.

(1) Water repellency of undercoat layer Measured in accordance with JIS P-8137. R0: a continuous trace showing a uniform width R2: a continuous trace showing a width slightly smaller than a water drop R4: a continuous trace but being cut at some places,
R6: One half of the trace is wet R7: One-fourth of the trace is wet by a long water droplet R8: One-quarter or more of the trace is a spherical droplet Are scattered R9: Some small spherical water droplets are scattered R10: It is completely rolling

(2) Ink Absorption The time until the printed ink dries was measured using an ink jet printer (Desk Writer C, manufactured by Hewlett-Packard Company). The evaluation was performed in the following five stages. 5: Very good ink drying time of less than 4 seconds 4 ... Good ink drying time of 4 to 6 seconds 3 ... Slightly good ink drying time of 7 to 10 seconds 2 ...・ Ink drying time is 11 to 15 seconds and there is a problem in practical use 1 ・ ・ ・ Ink drying time is 16 seconds or more and it is not practical

(3) Color developing property of ink Using an ink jet printer (Desk Writer C, manufactured by Hewlett-Packard Company), yellow, magenta,
The recorded portion of cyan was visually evaluated. The evaluation was performed in the following five stages. 5: The color of the recording portion is extremely clear 4: The color of the recording portion is clear 3: The color of the recording portion is normal, and there is no practical problem 2 ... The color of the recording portion Is sinking and there is a problem in practical use. 1 ... The color of the recorded part is sinking, very unclear and unusable

(4) Bleeding The outline of the dot printed 30 minutes after printing was observed with a zoom stereoscope (manufactured by Senner) at 50 times magnification using an ink jet printer (Desk Writer C, manufactured by Hewlett-Packard Company). The evaluation was performed in the following five stages. 5: The outline of the dots is extremely clear 4: The outline of the dots is clear 3 ... The outline of the dots is slightly blurred, but there is no problem in practical use 2 ... The outline of the dots It is blurred and there is a problem in practical use. 1 ... The outline of the dot is extremely blurred and cannot be used practically.

(5) Bleeding over time Using an ink jet printer (Desk Writer C, manufactured by Hewlett-Packard Company), outlines of the printed dots were observed at 50 times with a zoom stereoscope (manufactured by Senner) 48 hours after printing. The evaluation was performed in the following five stages. 5: The outline of the dots is extremely clear 4: The outline of the dots is clear 3 ... The outline of the dots is slightly blurred, but there is no problem in practical use 2 ... The outline of the dots It is blurred and there is a problem in practical use. 1 ... The outline of the dot is extremely blurred and cannot be used practically.

(6) Film Strength The cellophane tape (manufactured by Nichiban) was evaluated by a peel test. The evaluation was performed by sensory evaluation and evaluated in five stages. 5 ... Strength of coating film is very strong and good 4 ... Strength of coating film is strong and good 3 ... Strength of coating film is slightly weak but no problem in practical use 2 ... Strength of coating film is weak and there is practical problem 1 ... The coating film strength is too weak to be practical

(7) Water resistance of the coated film After the sample was immersed in water at 20 ° C. for 24 hours, the surface of the coated film was rubbed with a finger to evaluate whether or not the coated film was peeled off. 5: The coating film does not come off and has excellent water resistance. 4 ... The coating film tends to come off slightly. 3 ... The coating film tends to come off, but there is no practical problem. 2 ... The coating film comes off. There is a problem in practical use 1 ... The coating film is extremely easy to peel off, making it impractical

(8) Yellowing of coating film A sample was attached to a plate so that the coating layer was on the upper surface.
The coating was left outdoors under sunlight for a period of time, and the yellowing of the coating film was visually evaluated. 5: The coating film does not turn yellow at all. 4: The coating film turns yellow a little. 3: The coating film turns yellow, but there is no practical problem. There is an upper problem 1 ... The coating film is extremely yellow and cannot be used

[0049]

[Table 1]

As can be seen from Table 1, the ink jet recording sheets obtained in the examples are very excellent in all of the ink absorption, bleeding, coloring, coating strength and coating water resistance. On the other hand, the ink jet recording sheet obtained by the comparative example has ink absorbency,
Good results were not obtained in bleeding and coating water resistance.

Example II-1 One side of synthetic paper YUPO FPG-110 (manufactured by Oji Yuka Synthetic Paper, thickness: 110 μm) containing an inorganic pigment was coated with a UC layer coating material II-1 at an absolute dry weight of 10 g / bar using a bar coater. m ² performs dried coating provided an undercoat layer, 18 g / m ² coating absolute dry weight of the ink receiving layer coating II-1 thereon, and dried, to produce the ink jet recording sheet. "UC layer paint II-1" Kaolin (trade name: HYDRASPERSE, manufactured by Nissei Kyoei) 30 parts, calcium carbonate (trade name: Tamapearl T)
P-121: 70 parts, water-insoluble resin acrylic polymer latex (trade name: Apletan 760)
H: Hoechst Synthetic Co., Ltd. 20 parts “Ink receiving layer coating material II-1” Synthetic amorphous silica (trade name: Fine Seal X-37,
100 parts, partially saponified polyvinyl alcohol (trade name: Electrified Poval H-17, manufactured by Denki Kagaku Kogyo Co., Ltd., 96% saponification degree, average polymerization degree 1700) 30 parts, water-insoluble resin vinyl acetate polymer latex (trade name) :
Iodosol CD-5: 65 parts by Kanebo NSC), silanol-modified polyvinyl alcohol (trade name: R-11)
30, Kuraray, saponification degree 99%, average polymerization degree 1800)
3 copies

Example II-2 8 g of a UC layer coating material II-2 was used on one side of the synthetic paper YUPO FPG-110 used in Example II-1 using a bar coater in an absolutely dry amount.
/ M ² after coating, dried to form an undercoat layer, and the ink receiving layer coating material II-2 was dried on the undercoat layer in an absolutely dry amount of 20 g / m ^2.
Coating and drying were performed to produce an inkjet recording sheet. “UC layer paint II-2” 100 parts of calcium carbonate (trade name: Callite SA, manufactured by Shiroishi Central Research Institute), water-insoluble resin acrylic polymer latex (trade name: Iodosol 32A-501, manufactured by Kanebo NSC, Tg = 200 parts "Ink receiving layer paint II-2" 100 parts synthetic amorphous silica (trade name: Sylysia # 450, manufactured by Fuji Silysia) 100 parts, partially saponified polyvinyl alcohol (trade name: PVA420: manufactured by Kuraray, saponification degree 80) %,
20 parts, water-insoluble resin vinyl acetate polymer latex (trade name: Iodosol CD-5, average polymerization degree 2000)
Kanebo NSC) 5 parts, water-soluble cationic resin (trade name: Sumireze Resin 1001, Sumitomo Chemical) 10 parts

Example II-3 5 g of UC layer coating material II-2 was dried on one side of synthetic paper YUPO FPG-110 used in Example II-1 using a bar coater.
/ M ² coating and drying to provide an undercoat layer, on which the ink receiving layer coating material II-3 was dried at an absolutely dry amount of 12 g / m ^2.
Coating and drying were performed to produce an inkjet recording sheet. "Ink receiving layer coating material II-3" 100 parts of synthetic amorphous silica (trade name: Sylysia # 450, manufactured by Fuji Silysia), partially saponified polyvinyl alcohol (trade name: PVA205, manufactured by Kuraray, saponification degree 88%,
25 parts, water-insoluble resin Vinyl acetate polymer latex (trade name: Iodozol CD-5, manufactured by Kanebo NSC) 25 parts, water-soluble cationic resin (trade name: Sumireze Resin 1001, manufactured by Sumitomo Chemical) 8 copies

Example II-4 One side of a polyethylene terephthalate (PET) resin film (trade name: Lumirror T, manufactured by Toray Industries, Inc., thickness: 75 μm) was coated with a bar coater on one side and 8 g of the UC layer coating material II-4 was absolutely dried. / M ^{2 was} applied, an undercoat layer was provided, and an ink receiving layer coating material II-4 was applied thereon in an absolutely dry amount of 15 g / m ² to produce an ink jet recording sheet. "Undercoat layer paint II-4" 100 parts of calcium carbonate (Callite SA: manufactured by Shiroishi Central Research Institute), water-insoluble resin SBR latex (trade name: 0561, manufactured by Nippon Synthetic Rubber, Tg = -63 ° C) 1
00 parts “Ink receiving layer coating material II-4” 100 parts synthetic amorphous silica (trade name: Sylysia # 450, manufactured by Fuji Silysia), 100 parts fully saponified polyvinyl alcohol (trade name: PVA120, manufactured by Kuraray, saponification degree 99%,
25 parts by weight, water-insoluble resin vinyl acetate polymer latex (trade name: Iodosol CD-5,
25 parts, water-soluble cationic resin (trade name: Sumirezu Resin 1001, manufactured by Sumitomo Chemical) 10
Department

For each of the obtained coated sheet samples,
The following evaluation was performed, and the results are shown in Table 2. (1) Undercoat layer The water repellency was measured based on JIS P-8137. R0: a continuous trace showing a uniform width R2: a continuous trace showing a width slightly smaller than a water drop R4: a continuous trace but being cut at some places,
R6: One half of the trace is wet R7: One-fourth of the trace is wet by a long water droplet R8: One-quarter or more of the trace is a spherical droplet R9: Some small spherical water droplets scatter R10: Completely rolling (2) Ink drying property Ink jet plotter (NOVA JET III EN
(Made by CAD Co., Ltd.), and the time until the printed ink dries was measured.・ ・ ・: Very good ink drying time of less than 10 minutes ○-: Good and good ink drying time of 10 minutes to less than 20 minutes △: Ink drying time of 20 minutes to less than 30 minutes Insufficient for practical use x: Ink drying time is 30 minutes or more and there is a practical problem

(3) Print density Ink jet plotter (NOVA JET III EN
100% yellow, magenta 10
The print density of 0% and 100% cyan was sensory evaluated. ○ ・ ・ ・ Print density is good ○ － ・ ・ ・ Slightly bad but no practical problem △ ・ ・ ・ Insufficient in practical use × ・ ・ ・ Poor and bad in practical use (4) Bleed Ink jet plotter (NOVA JET III EN
CAD) and 100% cyan and 100% magenta
%, A 200% multicolor printing portion was subjected to a sensory evaluation. ◎ ・ ・ ・ Good without bleeding ○ ・ ・ ・ Slight bleeding is observed △ ・ ・ ・ Smeared but no problem in practical use × ・ ・ ・ Poor and bad in practical use

(5) Film Strength A cellophane tape (manufactured by Nichiban Co., Ltd.) was subjected to a peeling test and evaluated for sensory properties.・ ・ ・: Good coating strength ・ ・ ・-: slightly poor but no problem in practical use ・ ・ ・: insufficient in practical use ・ ・ ・: poor and problematic in practical use After immersion in water at 24 ° C. for 24 hours, the surface of the coating film was rubbed with a finger to evaluate whether the coating film was peeled off.・ ・ ・: The coating film does not peel off and has excellent water resistance. −: The coating film tends to peel off, but there is no practical problem. Is very easy to peel off and has practical problems

As can be seen from Table 2, the ink jet recording sheets obtained in the examples are very excellent in all of ink absorbency, bleeding, print density, coating strength and coating water resistance. On the other hand, the ink jet recording sheet obtained by the comparative example did not show good results in ink drying property, bleeding and coating water resistance.

[0059]

[Table 2]

[0060]

The ink-jet printer recording paper of the present invention is excellent not only in ink absorbency, bleeding and coloring, printing density, but also in coating strength and water resistance. This has the effect that a high-quality image can be displayed outdoors for a long time.

Continued on front page F-term (reference) 2C056 EA04 EA05 EA13 FC06 2H086 BA12 BA15 BA19 BA33 BA35 BA36 BA37

Claims (6)

[Claims] 1. An ink jet recording sheet comprising an undercoat layer and an ink receiving layer provided on a support made of a resin film, wherein the undercoat layer contains a water-insoluble resin, and the ink receiving layer is a synthetic amorphous. Silica and
An ink jet recording sheet containing a water-soluble resin and a nonionic water-insoluble resin as a binder. 2. The ink jet recording sheet according to claim 1, wherein the water-insoluble resin contained in the ink receiving layer is a vinyl acetate polymer. 3. The method according to claim 1, wherein the content of the water-insoluble resin in the total solid content of the binder contained in the ink receiving layer is from 20% by weight to 80% by weight. Sheet for inkjet recording. 4. The ink jet recording sheet according to claim 1, further comprising a cationic resin in the ink receiving layer. 5. The ink jet recording sheet according to claim 1, wherein the water-soluble resin in the ink receiving layer contains partially saponified polyvinyl alcohol. 6. The ink jet recording sheet according to claim 5, wherein the partially saponified polyvinyl alcohol contained in the ink receiving layer has a saponification degree of 90% or less.