JP2000203152A - Ink jet recording sheet and method for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having excellent printing characteristics, gloss, water resistance and damage resistance. SOLUTION: In the ink jet recording sheet comprising an ink receptive layer provided on at least one surface of a waterproofing support, the receptive layer contains a pigment having a mean particle size of 1 to less than 5 μm and a pigment having a mean particle size of 5 μm or above. A layer made of thermoplastic organic resin particles is provided on an upper layer of the ink receptive layer.

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 mainly using aqueous and pigment inks and an ink jet image forming method using the same. In particular, the present invention is not only excellent in image clarity, resolution and uniformity. In addition, the present invention relates to an ink jet recording sheet having a high gloss and a high water resistance after printing, and an ink jet image forming method using the same.

[0002]

2. Description of the Related Art Ink jet recording is free of noise and is capable of high-speed printing. Further, by using a plurality of ink nozzles, it is easy to perform multi-color recording, and multi-color ink jet recording is performed by various ink jet recording methods. In particular, use of an ink jet printer capable of forming a complex image quickly and accurately has attracted attention as a hard copy creation device for image information such as characters, various figures, and photographs created by a computer. Further, image information created by these computers is recorded on a transparent recording sheet by an ink jet printer, and this is also used as a document such as an OHP (overhead projector). In recent years, inkjet printers, which have attracted special attention, are used in applications where color image quality similar to photographs is required, such as color printing in the printing field, design image output in the design department, and large inkjet plotters. These are large format posters, displays, flags, etc. that can be easily created. Furthermore, in recent years, digital photographic images have become familiar, as represented by digital cameras, and attempts have been made to output these images with inexpensive inkjet printers. Inkjet printers equipped with exclusive modes and inks for photography have also been released. ing.

As a recording sheet used in the ink jet recording system, a pigment such as amorphous silica or the like and a water-soluble binder such as polyvinyl alcohol are provided on a support usually called ordinary paper or ink jet recording paper. Recording sheets provided with a porous ink-absorbing layer have been used, but none of the formulations has gloss and surface strength and printability are not satisfactory.

Further, there has been proposed a recording sheet having improved printability by containing pigments having different average particle diameters. For example, JP-A-3-133885 and JP-A-8-324102 propose that pigments having different average secondary particle diameters be used in combination. However, there are problems that the pigment used has a small particle size, which is inconvenient to handle, and that the paper itself, which is a support, is weak to water, and thus has low water resistance, which is a problem particularly in outdoor use. Also, in the part where the amount of ink is large,
There was a drawback that unevenness was generated on the support, making the finish unsightly.

In order to solve such a drawback, when a film made of water-resistant polyethylene terephthalate resin or the like is used instead of paper for the support, a water-soluble polymer is generally used for the ink absorbing layer, and the glossiness is high. Is sufficient, but there is a disadvantage that the ink absorbing layer has no water resistance.

Further, when a porous ink absorbing layer comprising a conventionally used pigment such as amorphous silica and a water-soluble binder such as polyvinyl alcohol and a binder such as latex is provided on the film base, More ink absorbing layers are required than if the support were paper. This is because, when the support is paper, the ink absorption is also partially carried out by the support, but by using a water-resistant support, it is necessary to cover all the absorption in the support with the ink absorbing layer. It is. However, when the number of ink absorbing layers is increased, there is a disadvantage that the film strength decreases and handling becomes inconvenient. In addition, gloss and water resistance were insufficient.

[0007] A number of recording papers and recording methods have been proposed in which an ink absorbing layer made of a porous pigment and a resin layer are disposed thereon to densify the resin layer after printing. Tokuhei 2-3
No. 1673, a combination of a pigment layer and a heat melting layer is used. In JP-A-7-2372348, JP-A-8-2090, JP-A-9-104163, and JP-A-9-104164, alumina hydrate is used for the pigment layer. Therefore, a combination with a hot melt layer has been proposed. Certainly, the water resistance and glossiness are improved by these combinations, but they have not been sufficient yet. Furthermore, the ink permeability is poor,
With respect to printability, defects such as ink overflow and ink bleeding have not been completely improved. In addition, the ink that cannot be absorbed by the ink absorbing layer has disadvantages such as inhibiting formation of a uniform film when the heat-fusible organic resin is thermally melted, and unevenness in coloring.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording sheet which sufficiently satisfies resolution, gloss and water resistance, and an ink jet image forming method using the same.

[0009]

The object of the present invention is to provide (1)
An ink jet recording sheet having an ink receiving layer on at least one surface of a waterproof support, wherein the ink receiving layer contains a pigment having an average particle diameter of 1 μm or more and less than 5 μm and a pigment having an average particle diameter of 5 μm or more. (2) An upper layer of the ink receiving layer according to (1) or (2), wherein the pigment of the ink receiving layer is a synthetic amorphous silica. And a layer formed of thermoplastic organic resin particles.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the ink jet recording sheet, when using the porous pigment for the ink absorbing layer to utilize the particle gap of the porous pigment and the internal pore of the porous pigment, the average particle diameter of the pigment used is the smoothness of the coated surface, the resolution and the like. It is known to affect the color development. As a result of intensive studies, the present inventors have found that pigments having an average particle diameter of 1 μm or more and less than 5 μm and an average particle diameter of 5 μm
m, the ink-absorbing property is improved by using an ink-jet recording sheet containing a pigment of not less than one kind of pigment, as a result, the film thickness can be reduced, and the resolution and the film strength can be improved. I found something.

In the ink jet recording sheet, a known organic or inorganic porous pigment is generally used as the pigment used in the ink receiving layer. In the present invention, inorganic fine particles are preferably used. For example, silica, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, zinc oxide, titanium oxide,
Satin white, aluminum silicate, inorganic white pigments such as lithopone, porous silica, fine alumina hydrate,
Colloidal silica or the like is used. In the present invention,
Among them, synthetic amorphous silica is preferably used in terms of economy and ease of use.

Particularly, the present invention is characterized in that a pigment having an average particle diameter of 1 μm or more and less than 5 μm and a pigment having an average particle diameter of 5 μm or more are used in combination on a waterproof support. Synthetic amorphous silica having an average particle diameter of 5 μm or more has a relatively large particle diameter and is used for forming voids for absorbing ink. However, if the average particle diameter exceeds 20 μm, the smoothness of the surface of the ink receiving layer is reduced, so that synthetic silica having an average particle diameter of 5 μm or more and 20 μm or less is preferable.

Further, the pigment of the present invention having an average particle diameter of 1 μm or more and less than 5 μm absorbs ink which causes bleeding with the pigment having an average particle diameter of 5 μm or more through smaller pores, and improves printability. In this case, it is not preferable to use a pigment having an average particle diameter that is too small, since there is a problem in handling in a manufacturing process, and a gap formed by the pigment having an average particle diameter of 5 μm or more is blocked to deteriorate printability.

The composition ratio of the pigment used together has an average particle diameter of 1 μm.
It is preferable that the weight ratio of m or more and less than 5 μm / 5 or more be in the range of 1/1 to 1/10. Average particle size 1
When the number of pigments having a size of at least μm and less than 5 μm is larger than this range, the voids formed by the synthetic amorphous silica having a size of 5 μm or more are closed, and the printability deteriorates. In addition, average particle size 5μ
When the number of pigments of m or more is larger than this range, the film strength is deteriorated and the color developability due to sinking of the ink is deteriorated. More preferably, the weight ratio is 1/1 to 1/5.

Generally, synthetic amorphous silica has a certain degree of particle size distribution, and the particle diameter has a different value within a certain range. The particle diameters of all the synthetic amorphous silicas used in the present invention do not need to be included in the above-mentioned values, and the values indicated as the average particle diameters of the synthetic amorphous silicas may be included in the range. However, the range of the particle size distribution is preferably as narrow as possible.

In the present invention, the coating amount of the ink receiving layer is preferably 3 to 40 g / m ² in terms of solid content, and 5 to 25 g / m ^2.
/ M ² is more preferred. The coating amount of the ink receiving layer is 3 g /
small and becomes unsightly image will full of ink than m ^2. Further, when the coating amount of the ink receiving layer is more than 40 g / m ² , in the case of the ink receiving layer using the inorganic fine particles, the ink sinks and not only an unclear image is obtained, but also the breaking property is improved. May be deteriorated and cracks may occur during transportation by the printer. In particular, in the present invention, since the support is provided with a waterproof support, when the coating amount of the ink receiving layer is large, the adhesion between the support and the image receiving layer is deteriorated,
The strength of the film decreases. Also, at the time of drying after application of the image receiving layer or drying after printing, distortion occurs between the waterproof support and the image receiving layer, and cracks are generated.
It is preferable to set m ² or less.

In general, when the support is paper, the amount of the ink receiving layer applied does not matter so much because the ink is absorbed by the support. However, when a waterproof support is used as the support, it is necessary to absorb all of the ink absorbed by the paper in the ink absorbing layer, and a large amount of the ink absorbing layer must be applied. But,
When a large amount of pigment is coated on a waterproof support, ink absorption can be ensured, but ink sinks and deteriorates color development and film strength, resulting in cracks during application and extremely inconvenient handling. Had the disadvantage of becoming In the present invention, the combined use of pigments having different average particle diameters enhances the ink absorbency, and makes it possible to reduce the coating amount of the ink receiving layer as compared with the case where only a pigment having a single average particle diameter is used. , Printability and film strength are improved.

When the ink receiving layer is made of inorganic fine particles, a binder is added for the purpose of improving the coating strength. Gelatin, polyvinylpyrrolidone, water-soluble cellulose derivative, polyvinyl alcohol,
SBR, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, styrene-acrylic acid in addition to various water-soluble polymers such as polyvinyl alcohol derivatives, polyacrylamide, and polyacrylic acid Copolymers, polymer latexes such as acrylates, vinyl chloride, and styrene may also be used. Among these binders, polyvinyl alcohol or a polyvinyl alcohol derivative is most preferably used.

The amount of the binder used together with the inorganic fine particles is not more than 50% by weight, preferably in the range of 30 to 1% by weight, based on the inorganic fine particles.

In the present invention, a surfactant may be added to the ink receiving layer in order to improve dot reproducibility in addition to the binder. The surfactant used may be any of anionic, cationic, nonionic and betaine types, and may be of low molecular weight or high molecular weight. One or two or more surfactants are added to the ink receiving layer coating liquid. When two or more surfactants are used in combination, an anionic surfactant and a cationic surfactant are used in combination. It is not preferable. The addition amount of the surfactant is preferably 0.001 g to 5 g, more preferably 0.01 to 3 g, per 100 g of the binder constituting the ink receiving layer.

In the present invention, the ink receiving layer can be hardened with an appropriate hardener for the purpose of improving water resistance and dot reproducibility. Specific examples of the hardener include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, and bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1. , 3,5 triazines, compounds having reactive halogens, divinyl sulfones, compounds having reactive olefins, N-methylol compounds, isocyanates, aziridine compounds, carbodiimide compounds, epoxy compounds, mucochloric acid and the like. There are halogen carboxaldehydes, dioxane derivatives such as dihydroxydioxane, and inorganic hardeners such as chrome alum, potassium alum, and zirconium sulfate. These can be used alone or in combination of two or more. The addition amount of the hardener is preferably 0.01 to 10 g, more preferably 0.1 to 5 g, per 100 g of the water-soluble polymer constituting the ink receiving layer.

It is known that a resin layer made of thermoplastic organic resin particles is arranged on an ink absorbing layer made of a porous pigment, and after printing, the resin layer is heated and densified to impart water resistance. However, a recording sheet in which these porous pigment layers and thermoplastic resin layers are combined does not simultaneously sufficiently satisfy resolution, gloss, and water resistance. As a result of intensive studies, the present inventors have found that in an ink jet recording sheet having an ink receiving layer on at least one surface of a waterproof support, the ink receiving layer has an average particle diameter of 1 μm.
a sheet made of a thermoplastic organic resin is provided on an upper layer of the ink jet recording sheet, which contains a pigment having a particle size of not less than 5 μm and a particle size of not more than 5 μm and a pigment having an average particle size of not less than 5 μm. It has been found out that the resolution, gloss, and water resistance are sufficiently satisfied at the same time.

In the present invention, a pigment having an average particle size of 1 μm or more and less than 5 μm and an average particle size of 5 μm
By using a pigment of m or more, the ink absorption capacity increases, and the amount of ink remaining in the thermoplastic resin particle layer decreases. As a result, high resolution, gloss, and water resistance can be obtained without adversely affecting film formation. . In addition, two particles having different particle sizes are used.
The combined use of the two types of silica reduces the amount of the ink receiving layer applied, so that the ink does not sink and the color developability after the heat fusion treatment is improved. In addition, the total coating amount decreases and the film strength increases.

In the present invention, the layer comprising the thermoplastic resin particles is preferably on the outermost surface, and after printing, the layer containing the thermoplastic resin particles is dissolved or melted by a solvent or heating to form a film, thereby providing water resistance. Is obtained.

The particle size of the thermoplastic organic resin particles in the present invention is preferably in the range of 1 μm to 20 μm.
When the particle size of the thermoplastic organic resin particles is smaller than 1 μm, the ink absorbency deteriorates, and a part of the ink remains in the thermoplastic organic resin, and has a sufficient water resistance to adversely affect the film property. I can't get it. When the particle size of the thermoplastic organic resin particles exceeds 20 μm, the ink absorbability is good, but when the thermoplastic organic resin particles are densified by heating, sufficient denseness cannot be obtained and gloss is reduced. This is not preferred because the water resistance is lowered. In order to obtain a more uniform coating, thermoplastic organic resin particles having a particle size of 3 μm to 10 μm are more preferably used.

The thickness of the thermoplastic organic resin layer in the present invention is preferably from 1 g / m ² in solid coating amount is 30 g / m ^2. When the thickness of the thermoplastic organic resin particles is less than 1 g / m ² , a film that uniformly covers the surface of the ink receiving layer cannot be obtained when the thermoplastic organic resin particles are heated and densified,
Sufficient water resistance cannot be obtained. Further, when the thickness of the thermoplastic organic resin layer exceeds 30 g / m ² , a part of the ink does not reach the ink receiving layer and remains in the thermoplastic organic resin layer, adversely affecting uniform film formation. , It is not preferable because the water resistance is lowered. More preferably, the thickness is 5 g / m ² to 15 g / m ² .

The thermoplastic organic resin particles in the present invention are not particularly limited as long as they are organic substances having thermoplasticity, but polyethylene, polypropylene, polyisobutylene, polyethylene, etc. from the viewpoints of film properties, film strength, film gloss, film forming properties, etc. Waxes, polyethylene oxide, polytetrafluoroethylene, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer and other olefin homo- or copolymers or derivatives thereof, polychlorinated Vinyl, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylate copolymer, polyvinylidene chloride, styrene butadiene rubber, NBR rubber and the like are used alone or in combination.

The minimum film forming temperature (MFT) of the thermoplastic organic resin particles in the present invention is preferably in the range of 40 ° C. to 150 ° C. The minimum film forming temperature means a minimum temperature required for forming a film by bonding the thermoplastic organic resin particles. This minimum film formation temperature can be measured by the temperature gradient plate method as described in Soichi Muroi, “Chemistry of Polymer Latex” (1997). If the minimum film forming temperature of the thermoplastic organic resin particles is lower than 40 degrees, the thermoplastic organic resin particles are formed into a film in a usual ink jet recording sheet manufacturing process, and the ink absorbency is deteriorated. Further, it is difficult to produce an ink jet recording sheet at a temperature at which the thermoplastic organic resin particles do not form a film from the viewpoint of drying efficiency. Further, when the minimum film forming temperature of the thermoplastic organic resin particles exceeds 150 ° C., a sufficient amount of heat cannot be obtained by a normal heat treatment, and a uniform film is difficult to be formed. Or drop. Further, if the temperature is raised to the minimum film formation temperature or higher in order to obtain a uniform film, the waterproof support is undesirably deformed or deteriorated by heat, which is unfavorable because gloss is lowered or smoothness is lowered. Furthermore, in order to optimize the ease of film formation, the uniformity of the film, and the strength of the film, the minimum film formation temperature (MFT) of the thermoplastic organic resin particles in the present invention is 60.
More preferably, it is in the range of from 130C to 130C.

In the present invention, in the layer comprising the thermoplastic organic resin particles, in addition to the thermoplastic organic resin particles, a carnauba wax, an oculi wax, a candelilla wax, a rice wax, a wood wax, a beeswax, which is a hot-melt substance. Natural waxes and derivatives such as lanolin, whale wax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, petrolatum, and interfaces such as sorbitan stearate, propylene glycol monostearate, glycerin stearate, and polyoxyethylene stearate Activators, lauric acid, palmitic acid, myristic acid, stearic acid,
Higher fatty acids such as behenic acid, aluminum stearate, lead stearate, barium stearate, zinc stearate, zinc palmitate, methylhydroxystearate, glycerol monohydroxystearate or derivatives thereof such as metal salts, amide esters, etc. It may be appropriately added for the purpose of improving the film properties when the plastic organic resin particles are densified by heating and lowering the apparent minimum film forming temperature.

In the present invention, the layer composed of the thermoplastic organic resin particles may contain a trace amount of a water-soluble binder or a polymer latex having a low MFT (for example, 30 ° C. or lower) in order to obtain a coating property after coating. Good. Its content is about 1 to 20% by weight, preferably 1 to 10% by weight, based on the thermoplastic resin particles. An increase in the content of the binder is not preferable because the water resistance is significantly reduced. Preferred water-soluble binders include polyvinyl alcohol.

After printing, these resin layers are heated to 100 to 140 ° C.
By heating to a certain degree, the thermoplastic organic resin is heated and densified to form a transparent film, whereby an image having high gloss and excellent water resistance can be formed. Here, the type of ink used for printing may be either dye ink or pigment ink.

In the present invention, in addition to the above-mentioned inorganic pigment, colloidal silica, surfactant and hardener, a coloring dye may be further provided in the ink receiving layer and the layer comprising the thermoplastic organic resin particles.
Fixing agents for color pigments, ink dyes, UV absorbers, antioxidants, pigment dispersants, defoamers, leveling agents, preservatives,
Known various additives such as a fluorescent whitening agent, a viscosity stabilizer, and a pH adjuster can also be added.

In the present invention, the ratio (weight ratio) of the ink receiving layer and the layer composed of thermoplastic organic resin particles is 5 parts by weight of the layer composed of ink receiving layer / thermoplastic organic resin particles.
/ 1 to 1/1 is preferred.

The coating method of the ink receiving layer coating liquid in the present invention may be a commonly used coating method (eg, slide lip method, curtain method, extrusion method, air knife method, roll coating method, rod bar coating method, etc.). ) Is used, but when a layer composed of the ink receiving layer and the thermoplastic organic resin particles is sequentially applied, the layer composed of the thermoplastic organic resin particles is preferably applied by an air knife method. In addition, a slide lip system and a curtain system are preferably used because a layer composed of an ink receiving layer and thermoplastic organic resin particles can be provided at a time.

In the present invention, the ink recording sheet has a two-layer structure including an ink receiving layer and a layer composed of thermoplastic organic resin particles, but the ink receiving layer in the present invention may have a further multilayer structure. In general, the ink receiving layer has a multi-layered structure by arranging layers having functions such as an ink absorbing layer, an ink fixing layer, a water resistant layer, and an ink transmitting layer as needed. Examples of the multilayer structure of the ink absorbing layer include JP-A-57-89954 and JP-A-60-224.
No. 578 and No. 61-12388.

As the waterproof support used in the present invention, either a transparent support or an opaque support can be used. As the transparent support, any conventionally known ones can be used, for example, polyester resin, diacetate resin, triacetate resin, acrylic resin, polycarbonate resin, polyvinyl chloride, polyimide resin, cellophane, film or plate of celluloid and the like and A glass plate and the like are exemplified, and among these, a film made of polyethylene terephthalate is most preferably used.

The thickness of such a transparent waterproof support is preferably about 10 to 200 μm.

As the opaque waterproof support, synthetic paper,
Conventionally known materials such as resin-coated paper, opaque film containing pigment, and foamed film can be used. From the viewpoint of gloss and smoothness, resin-coated paper and various films are more preferable,
Films made of resin-coated paper similar to a photographic support from the feeling of touch and high quality and a polyethylene terephthalate containing a pigment having high whiteness and strength are more preferably used.

The base paper constituting the resin-coated paper as the waterproof support preferably used in the present invention is not particularly limited, and generally used paper can be used. More preferably, the base paper is used, for example, for a photographic support. Smooth base paper is preferred. As the pulp constituting the base paper, natural pulp, recycled pulp, synthetic pulp or the like may be used alone or in combination of two or more. The base paper is blended with additives generally used in papermaking, such as a sizing agent, a paper strength enhancer, a filler, an antistatic agent, a fluorescent whitening agent, and a dye.

Further, a surface sizing agent, a surface paper strengthening agent, a fluorescent whitening agent, an antistatic agent, a dye, an anchoring agent and the like may be coated on the surface.

The thickness of the base paper is not particularly limited, but preferably has good surface smoothness, for example, by applying pressure by using a calender or the like during or after paper making, and the basis weight is 30 to 250 g / m ² is preferred.

As the resin of the resin-coated paper, a polyolefin resin or a resin curable by an electron beam can be used.
Examples of the polyolefin resin are low-density polyethylene, high-density polyethylene, polypropylene, polybutene, a homopolymer of an olefin such as polypentene or a copolymer of two or more olefins such as an ethylene-propylene copolymer and a mixture thereof, Those having various densities and melt viscosity indices (melt index) can be used alone or in combination.

In the resin of the resin-coated paper, white pigments such as titanium oxide, zinc oxide, talc and calcium carbonate, fatty acid amides such as stearamide, arachidic amide, zinc stearate, calcium stearate, stearic acid Aluminum, fatty acid metal salts such as magnesium stearate, antioxidants such as Irganox 1010 and Irganox 1076, blue pigments and dyes such as cobalt blue, ultramarine blue, cecilian blue, and phthalocyanine blue, cobalt violet, fast violet, and manganese purple It is preferable to add various additives such as magenta pigments and dyes, fluorescent brighteners and ultraviolet absorbers in an appropriate combination.

The resin-coated paper, which is preferably used in the present invention, is produced by a so-called extrusion coating method in which, in the case of a polyolefin resin, a heat-melted resin is cast on a running base paper, both sides of which are made of resin. Coated. In the case of a resin that is cured by an electron beam, the resin is applied by a commonly used coater such as a gravure coater or a blade coater, and then irradiated with an electron beam to cure and coat the resin. Further, before coating the resin on the base paper, the base paper is preferably subjected to an activation treatment such as a corona discharge treatment or a flame treatment. The surface (surface) of the support on which the ink receiving layer is applied has a glossy surface, a matte surface, and the like, depending on the application, and the glossy surface is used particularly advantageously. It is not necessary to coat the back surface with a resin, but it is preferable to coat the resin from the viewpoint of curling prevention. The back surface is usually a matte surface, and the front surface or both front and back surfaces can be subjected to an activation treatment such as a corona discharge treatment or a flame treatment as required. The thickness of the coating resin layer is not particularly limited, but is generally 5 to 50 μm thick on the surface or on both sides.

The support in the present invention may be coated with various back coat layers for antistatic properties, transport properties, curling prevention properties, and the like. The back coat layer can contain an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like in an appropriate combination.

In the present invention, an ink jet image forming method for obtaining an ink jet image by heating and densifying thermoplastic organic particles by heating the ink jet recording sheet may be carried out at a temperature not lower than the minimum film forming temperature of the thermoplastic organic particles. The heating means is not particularly limited. Specifically, a ferromagnetic iron that directly applies hot air, applies an iron, passes through a heating roll such as a laminator, which is often used for post-processing of large-format printer output images, and adheres to a heated mirror drum used for drying photographs, etc. For example, a method using a type dryer may be used. Among these methods, a method using a laminator that can be heated and densified by passing between pressurized rolls is more preferable because a large-sized sheet can be uniformly heat-treated.

[0047]

EXAMPLES The present invention will be described below in detail with reference to examples, but the contents of the present invention are not limited to the examples. In addition, "parts" means parts by weight.

Example 1 <Recording sheet 1 of the present invention> A bar coater was applied on a resin-coated paper support shown below so that the coating amount of the ink-receiving layer shown below was 18 g / m ² on a solid basis. Apply using
The temperature and humidity of the drying zone were controlled so that the surface wet bulb temperature was 70 ° C. or lower, and the ink was dried to prepare an ink jet recording sheet of the present invention.

Resin-coated paper; LBKP (50 parts) and LBS
A resin composition comprising low-density polyethylene (70 parts), high-density polyethylene (20 parts), and titanium oxide (10 parts) was coated on a surface of a 120 g / m ² base paper comprising a pulp blend of P (50 parts) at 25 g / m ^2. m ² was coated, the back surface dense polyethylene (50 parts) and low-density polyethylene resin coated paper a resin composition formed by 25 g / m ² coating consisting of (50 parts).

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size: 6 μm) 70 parts manufactured by Tokuyama Co., Ltd. Silica Fine Seal X-30 (particle size: 3 μm) 30 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVAR -1130 Kuraray Co., Ltd. 20 parts Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Co., Ltd. 20 parts

<Recording Sheet 2 of the Present Invention> A recording sheet was prepared in the same manner as the recording sheet 1 except that the composition of the ink receiving layer coating solution was as described below.

Liquid composition of ink receiving layer: Silica Mizukasil P-78D (particle size 8 μm) 70 parts manufactured by Mizusawa Chemical Co., Ltd. Silica Fine Seal X-30 (particle size 3 μm) 30 parts manufactured by Tokuyama Corporation PVA 235 (type) ) Kuraray 20 parts Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Co., Ltd. 20 parts

<Recording Sheet 3 of the Present Invention> A recording sheet was prepared in the same manner as the recording sheet 1 except that the coating liquid composition of the ink receiving layer was as follows.

Liquid composition of ink receiving layer: Silica Mizukasil P-78F (particle size 13 μm) 70 parts manufactured by Mizusawa Chemical Co., Ltd. Silica Fine Seal X-45 (particle size 4.5 μm) 30 parts manufactured by Tokuyama Co., Ltd. Silanol modified PVA R-1130 Kuraray Co., Ltd. 20 parts Cation fixing agent Sumireze Resin 1001 Sumitomo Chemical Co., Ltd. 20 parts

<Recording Sheet 4 of the Present Invention> A recording sheet was prepared in the same manner as the recording sheet 1 except that the coating liquid composition of the ink receiving layer was as described below.

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size: 6 μm) 30 parts manufactured by Tokuyama Co., Ltd. Silica Fine Seal X-30 (particle size: 3 μm) 70 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVAR -1130 Kuraray Co., Ltd. 20 parts Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Co., Ltd. 20 parts

<Recording sheet 5 of the present invention> The recording sheet 1 described above, except that a white polyethylene terephthalate film (97 μm, manufactured by ICI Melinex) was used as a support.
A recording sheet was produced in the same manner as described above.

Comparative Example 1 A recording sheet was prepared in the same manner as the recording sheet 1 except that the composition of the ink receiving layer was changed as follows.

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size: 6 μm) 100 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVA R-1130 20 parts manufactured by Kuraray Co., Ltd. Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Industrial Co., Ltd. 20 parts

Comparative Example 2 A recording sheet was prepared in the same manner as in the recording sheet 1 except that the composition of the ink receiving layer was changed as follows.

Liquid composition of ink receiving layer: Silica Fine Seal X-30 (particle size: 3 μm) 100 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVA R-1130 20 parts manufactured by Kuraray Co., Ltd. Cation fixing agent Sumirezu Resin 1001 Sumitomo Chemical Industrial Co., Ltd. 20 parts

Comparative Example 3 A recording sheet was prepared in the same manner as in the recording sheet 1 except that the coating liquid composition of the ink receiving layer was as described below.

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size: 6 μm) 70 parts manufactured by Tokuyama Co., Ltd. Silica Cataloid S-30L (particle size: 0.01 to 0.02 μm) 30 parts manufactured by Catalyst Chemicals, Inc. Silanol-modified PVA R-1130 20 parts manufactured by Kuraray Co., Ltd. Cationic fixing agent Sumirezu Resin 1001 20 parts manufactured by Sumitomo Chemical Co., Ltd.

Comparative Example 4 A recording sheet was prepared in the same manner as in Comparative Example 1, except that the coating amount of the ink receiving layer was adjusted such that the coating amount of the solid content was 25 g / m ² . .

For each sheet obtained as described above, an evaluation image was printed on a Novajet PRO (manufactured by ENCAD) ink jet large format printer using a pigment ink (GO ink).

Color development: Y, M, C, R, G, B, and K colors are output at a density of 100% to a size of 3 cm × 5 cm, the image portion is visually observed, and the vividness of each color in the printing portion is obtained. Was determined. It is one of the indexes indicating the sharpness of an image. The evaluation criteria are as follows.

A: Very vivid color development. ：: Vivid color development. Δ: The color is slightly dull, but it can be used. ×: The color is dull and cannot be used.

Bleeding: A single color or a multicolor was continuously recorded, and it was visually determined whether or not adjacent print portions flowed out to each other or to one side. It is one of the indices indicating the sharpness and resolution of an image. The evaluation criteria are as follows.

A: Excellent without any problem. ：: Excellent. Δ: Can be used. X: Poor.

Film strength: A tape was adhered to the ink jet recording sheet, and the degree of peeling of the film after peeling was visually judged. The evaluation criteria are as follows.

A: The surface does not change at all. ：: Part of the surface was peeled off, but there was no problem in practical use. Δ: The surface is peeled off, but at a practically usable level. X: This is a level at which the film is completely peeled off and the image collapses and cannot be used practically.

[0072]

[Table 1]

As is clear from the above results, the ink jet recording sheet of the present invention showed good results in any of the evaluation items.

Example 2 <Recording Sheet 6 of the Present Invention> On the resin-coated paper support shown in Example 1, the following layers composed of an ink receiving layer coating solution and thermoplastic organic resin particles were sequentially applied. The ink receiving layer was applied using a bar coater so that the applied amount of the solid content was 18 g / m ² , and dried by controlling the temperature and humidity in the drying zone so that the surface wet bulb temperature was 70 ° C. or less. The upper layer is coated with an air knife method so that the solid content of the layer made of thermoplastic organic resin particles is 10 g / m ^2, and then the temperature and humidity of the drying zone are controlled so that the surface wet bulb temperature is 60 ° C. or less. Thus, an ink jet recording sheet of the present invention was produced.

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size 6 μm) 70 parts manufactured by Tokuyama Co., Ltd. Silica Fine Seal X-30 (particle size 3 μm) 30 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVAR -1130 Kuraray Co., Ltd. 20 parts Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Co., Ltd. 20 parts

Liquid composition of layer composed of thermoplastic organic resin particles; polyethylene emulsion (10% aqueous dispersion) 100 parts Chemipearl M-200, particle size 6 μm, PVA117 (10% aqueous solution) manufactured by Mitsui Chemicals, Inc. Kuraray 8 parts Colloidal silica Snowtex XL, Nissan Chemical 8 parts

<Recording Sheet 7 of the Present Invention> Except that the thermoplastic resin particles in the thermoplastic resin layer were ethylene-vinyl acetate copolymer (Chemipearl V-200, particle size 7 μm, manufactured by Mitsui Chemicals, Inc.) The recording sheet 7 was produced in the same manner as the recording sheet 6.

Comparative Example 5 A recording sheet was prepared in the same manner as the recording sheet 6 except that the composition of the ink receiving layer was changed as follows.

Liquid composition of ink receiving layer: Silica Fine Seal X-60 (particle size: 6 μm) 100 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVA R-1130 20 parts manufactured by Kuraray Co., Ltd. Cationic fixing agent Sumirezu Resin 1001 Sumitomo Chemical Industrial Co., Ltd. 20 parts

Comparative Example 6 A recording sheet was prepared in the same manner as the recording sheet 6 except that the composition of the ink receiving layer was changed as follows.

Liquid composition of ink receiving layer: Silica Fine Seal X-30 (particle size: 3 μm) 100 parts manufactured by Tokuyama Co., Ltd. Silanol-modified PVA R-1130 20 parts manufactured by Kuraray Co., Ltd. Cation fixing agent Sumirezu Resin 1001 Sumitomo Chemical Industrial Co., Ltd. 20 parts

Comparative Example 7 A recording sheet was prepared in the same manner as in Comparative Example 5, except that the solid content of the ink receiving layer in Comparative Example 5 was changed to 28 g / m ² .

With respect to the ink jet sheet of Example 2, a printed matter was prepared in the same manner as in Example 1, dried sufficiently, and then printed with a polyester film using a large-size laminator (M-36 manufactured by Fuji Film Co., Ltd.). Heat densification treatment was performed by passing two heating rollers (temperature: 120 ° C.) while sandwiching. In addition to the evaluation items of Example 1 for the sample subjected to the heat densification treatment,
A water resistance quality test was performed, and the results shown in Table 2 were obtained.

Gloss: The gloss of the surface of the ink jet recording paper sheet subjected to the heat densification treatment was measured at 60 degrees, and the average value was calculated. The higher the numerical value, the higher the gloss and the more preferable.

Water resistance: The ink jet recording paper sheet subjected to the printing of the evaluation image and the heat densification treatment was exposed to water at room temperature for 24 hours.
The image was immersed for a period of time, and the image was visually judged for bleeding and concentration reduction due to dissolution into water. The evaluation criteria are as follows.

：: No bleeding, no decrease in density, no change in image. Δ: The density was slightly lowered, but the image was kept. X: Ink melted out and the image collapsed.

[0087]

[Table 2]

As is clear from the results in Table 2, the present invention has high gloss, excellent water resistance and excellent film strength.

Continued on the front page F-term (reference) 2C056 EA04 EA13 FC06 HA46 2H086 BA05 BA15 BA31 BA33 BA45 4F100 AA20B AA21 AJ04 AK01C AK04 AK05 AK06 AR00A AR00B BA02 BA03 BA07 BA10A BA10C CA13B DE01B DE01C DG10E06 J05 EB10 J02 EB10 J462

Claims (4)

[Claims] 1. An ink jet recording sheet having an ink receiving layer on at least one surface of a waterproof support,
An ink jet recording sheet, wherein the ink receiving layer contains a pigment having an average particle diameter of 1 μm or more and less than 5 μm and a pigment having an average particle diameter of 5 μm or more. 2. The ink jet recording sheet according to claim 1, wherein the pigment of the ink receiving layer is synthetic amorphous silica. 3. The ink jet recording sheet according to claim 1, wherein a layer made of thermoplastic organic resin particles is provided on the ink receiving layer. 4. An image forming method using the ink jet recording sheet according to claim 3, wherein after printing on the ink jet recording sheet, the thermoplastic resin particles are heated by heating the ink jet recording sheet. An ink-jet image forming method, comprising heating and densifying.