JP2000033770A - Ink receiving sheet and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ink absorbability and tearability in an OHP ink jet ink receiving sheet. SOLUTION: An ink image receiving layer is formed on at least one surface of a base sheet made of a stretched styrene resin sheet to obtain an ink image receiving sheet. The stretched styrenic resin sheet is tearable. The ink image receiving layer contains at least a hydrophilic polymer, and may further contain a particulate lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tearable ink image receiving sheet and a method for producing the same. More specifically, ink absorptivity in an inkjet recording system,
An ink receiving sheet having excellent ink fixing properties and printing properties, and which can be easily torn when shredded by a shredder or the like, and which has sufficient transparency to be used for overhead projector (OHP) sheets and the like. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Ink-jet recording systems have been rapidly spreading in recent years because they can be easily made full-color, have low noise, and have excellent print quality. In the inkjet recording, a water-based ink is mainly used in terms of safety and recording suitability, and the recording is performed by flying small ink droplets from a nozzle toward a recording sheet. Therefore, the recording sheet is required to quickly absorb the ink.
That is, in a recording sheet having a low ink absorbency, the ink remains on the surface of the recording sheet for a long time even after the recording is completed, and the recording portion may be contacted by a part of the apparatus, a contact of a handler, or a superposition of the recording sheet. Gets dirty. In the high-density image area, a large amount of supplied ink is mixed and flows without being absorbed, resulting in an unclear image.

In recent years, an overhead projector (OHP) using a plastic sheet as a recording material
However, as the price and size have been reduced, they have been introduced for presentations in all fields, and many OHP recordings have been easily created using the above-described ink jet printer. When an image is recorded on a plastic sheet, the image becomes unclear due to contact or the like even after ink absorption, so that the sheet is required to have not only rapid ink absorption but also high ink fixability.

Further, such a plastic sheet (especially, an OHP sheet) is required to have high transparency due to the method of use, and does not adhere even if the sheets are stacked before or after recording. Good handling is required.

[0005] On the other hand, with the great improvement of the recording method and the recording medium or the recording material, a large number of recording sheets are generated as printing devices such as high-quality and low-cost printers are easily available. Its disposal is a problem. In particular, when discarding a highly confidential recording sheet, a shredder such as a shredder is generally used in many cases. When using a shredding machine, if the recording material is a material that can be shredded relatively easily, such as paper, good shredding can be expected. However, recorded matter printed on a plastic sheet or the like is inferior in shredding property as compared with paper, and is expensive to dispose. In particular, when the sheet is supplied to the shredder in the form of a sheet, the sheet jams and the shredding becomes impossible.

[0006] Further, as an OHP sheet,
Although a polyester resin such as polyethylene terephthalate is used, it is difficult to shred by hand or mechanically because the sheet itself is strong.

Japanese Patent Application Laid-Open No. 9-226233 discloses polyester, polystyrene and the like as supports.
It is disclosed that an ink absorbing layer is formed on at least one side of such a support to obtain an ink jet recording sheet.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tearable ink image receiving sheet having high ink absorption and ink fixing properties, and a method of manufacturing the same.

It is another object of the present invention to provide an ink receiving sheet having high transparency and capable of suppressing blocking between sheets even when the sheets are overlapped with each other, and a method for producing the same.

[0010]

Means for Solving the Problems When the present inventors have formed an ink image receiving layer on at least one surface of a stretched styrene resin sheet, the ink absorbing property of the ink image receiving sheet can be improved.
The inventors have found that the tearability can be significantly improved while maintaining the high transparency while improving the ink fixing property and printing property, and completed the present invention.

That is, the ink image receiving sheet of the present invention comprises:
An ink image receiving layer is formed on at least one surface of a base sheet made of a stretched styrene resin sheet. The stretched styrene-based resin sheet can be torn in vertical and horizontal directions and diagonally. The ink image receiving layer may contain a hydrophilic polymer, and may further contain a particulate lubricant.

The present invention also includes a method for producing an ink image receiving sheet in which the image receiving layer is formed on at least one surface of a stretched styrene resin sheet.

In this specification, the term "hydrophilic polymer" means various polymers having an affinity for water, and is used to include a water-absorbing polymer and a water-soluble polymer. In this specification, an acrylic monomer and a methacrylic monomer are generically referred to as a (meth) acrylic monomer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The ink receiving sheet of the present invention comprises a base sheet and an ink receiving layer, and the base sheet is formed of a stretched styrene resin sheet. Such an ink image receiving sheet is useful as an ink jet recording sheet for recording with flying ink droplets.

[Substrate sheet] The stretched styrene resin sheet constituting the ink image-receiving sheet may be opaque, translucent or transparent depending on the use as long as the tearability is not impaired. When used for, for example, it is usually transparent.

The styrenic resin constituting the styrenic resin sheet can be composed of an aromatic vinyl compound alone or a copolymer, or a copolymer of an aromatic vinyl compound and a copolymerizable vinyl monomer.

Examples of the aromatic vinyl compound include styrene, alkylstyrene (for example, vinyltoluenes such as o-, m- and p-methylstyrene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, p-methylstyrene).
-T-butylstyrene, etc.), α-alkylstyrene (eg, α-methylstyrene), halostyrene (eg, o-, m- and p-chlorostyrene, p-bromostyrene, etc.). These aromatic vinyl monomers can be used alone or in combination of two or more. Preferred styrene monomers include styrene, vinyltoluene, α-methylstyrene and the like, and styrene is particularly preferred.

Examples of the copolymerizable vinyl monomer include, for example,
(Meth) acrylonitrile, alkyl (meth) acrylate, vinyl ester-based monomer (eg, vinyl acetate), hydroxyl group-containing monomer [hydroxy C ₁ such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, etc. _-4 alkyl (meth) acrylate, etc.], glycidyl group-containing monomer [glycidyl (meth) acrylate, etc.], carboxyl group-containing monomer [(meth) acrylic acid, maleic anhydride, fumaric acid, etc.], imide monomer Monomers (maleimide, N-methylmaleimide, N-phenylmaleimide, etc.). The alkyl (meth) acrylate includes methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
_C1-20 alkyl (meth) acrylates such as lauryl (meth) acrylate are included. These vinyl monomers can be used alone or in combination of two or more.

Examples of highly transparent styrene resins include polystyrene, acrylonitrile styrene copolymer (AS resin), styrene- (meth) acrylic acid copolymer, styrene-maleic anhydride copolymer, styrene-
(Meth) acrylic acid ester copolymer (styrene-methyl methacrylate copolymer, etc.), styrene- (meth) acrylic acid ester- (meth) acrylic acid copolymer (styrene-methyl methacrylate- (meth) acrylic acid) Copolymers), styrene- (meth) acrylate-maleic anhydride copolymers (styrene-methyl methacrylate-maleic anhydride copolymer) and the like.

In the case of a copolymer, the form of the copolymer is not particularly limited, and may be, for example, a random, block, tapered block, graft copolymer or the like. These styrene resins can be used alone or in combination of two or more.

If necessary, the styrene resin may contain various additives such as a stabilizer such as an ultraviolet absorber or an antioxidant, a plasticizer, a filler, a slip agent, an anti-blocking agent, a nucleating agent, a crosslinking agent, and a charging agent. Inhibitors, flame retardants, light-shielding agents such as titanium oxide, coloring agents, mineral oil, etc. are added to impart various properties such as heat resistance, cold resistance, impact resistance, flame retardancy, moldability, or May be improved.

The base sheet is obtained by molding the styrene resin into a sheet or film by a conventional method. The base sheet is a stretched sheet (a uniaxially stretched sheet, a biaxially stretched sheet, or the like). Examples of the sheet forming method include an extrusion method (T-die method, inflation method, etc.), and examples of the stretching method include stretching methods such as a tenter method, a tube method, and an inflator method (uniaxial stretching method, biaxial stretching method). Etc.).

The stretching ratio of the substrate sheet is 1 to 3 times, preferably 1 to 2 times in both the longitudinal and transverse directions.
It is 5 times (for example, 1 to 2 times), usually about 1.5 to 2 times.

The sheet may be a single layer, a laminated sheet of a plurality of resin layers composed of styrene resins having different compositions, a layer composed of a styrene resin layer and another resin layer (for example, Olefin-based resin such as polyethylene and polypropylene).

Since the base sheet is made of a stretched styrene resin sheet, it can be torn in any direction, such as a vertical, horizontal, or oblique direction.

The tear strength of the base sheet is measured according to JIS.
K7128 (Tear of plastic film and sheet
Test method), 0.05 to 0.25 kgf / m
m, preferably 0.08 to 0.2 kgf / mm (for example,
About 0.1 to 0.2 kgf / mm).
It is about 0.1 to 0.16 kgf / mm. Also the thickness
100 μm polyethylene terephthalate film (1
Film (heat treated at 10 ° C for 3 minutes)
S_PET, A 130 μm thick base sheet (stretched sheet) of the present invention.
Tear strength of Styrene resin sheet)_STThen
Tear strength ratio S_ST/ S _PET= 0.01 / 1 to 0.7 / 1,
Preferably 0.05 / 1 to 0.5 / 1 (for example, 0.0
5/1 to 0.4 / 1), more preferably 0.1 / 1 to
It is about 0.3 / 1. Note that a substrate having an ink image receiving layer
The material sheet has the same tear strength and tear as the above base sheet.
The intensity ratio is shown.

The thickness of the substrate sheet can be selected according to the application, and is usually 30 to 500 μm, preferably 40 to 250 μm.
m (for example, 50 to 200 μm), and the thickness of the OHP film is usually 30 to 200 μm (for example, 50 to 200 μm).
１５０150 μm).

The base sheet may be subjected to a surface treatment such as a corona discharge treatment or an undercoat treatment, if necessary, depending on the purpose or application, in order to improve the adhesiveness with the ink image receiving layer and the adhesive described later. You may. When the corona discharge treatment is performed, when a cationic polymer containing a reactive group (particularly, an alkoxysilyl group) is used as a component of the ink image receiving layer described later, the reactivity generated on the base sheet by the corona discharge treatment Group (hydroxyl group or carboxyl group) and reactive group (alkoxysilyl group)
The adhesion between the substrate sheet and the ink image receiving layer can be greatly improved.

Since the base sheet constituting the ink image-receiving sheet of the present invention is constituted by a stretched styrene resin sheet, the total light transmittance of the sheet is about 88 to 97% (for example, 90 to 95%). It is also useful as a sheet for OHP or the like that requires high transparency.

[Ink image receiving layer] In the ink image receiving sheet of the present invention, an ink image receiving layer is formed on at least one surface of the base sheet. The ink image receiving layer can be formed of an organic or inorganic material, and preferably contains at least a hydrophilic polymer. Further, when the ink image-receiving layer is constituted by combining a cationic polymer (preferably a cationic emulsion containing a cationic polymer), the ink absorbability can be further improved.

[Hydrophilic polymer] As the hydrophilic polymer,
For example, a hydrophilic natural polymer or a derivative thereof (starch, corn starch, sodium alginate, gum arabic, gelatin, casein, dextrin, etc.), a cellulose derivative (methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate, cyanoethyl cellulose, etc.) , Vinyl alcohol-based polymers (such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer), ethylene-based polymers (such as ethylene-maleic anhydride copolymer), and vinyl acetate-based copolymers (such as vinyl acetate-methyl acrylate). Polymer), a polymer having a carboxyl group or a sulfonic acid group or a salt thereof [acrylic polymer (poly (meth) acrylic acid or a salt thereof (ammonium, Alkali metal salts such as lithium), methyl methacrylate- (meth) acrylic acid copolymer, acrylic acid-polyvinyl alcohol copolymer, etc.), vinyl ether polymers (polyvinyl alkyl ethers such as polyvinyl methyl ether and polyvinyl isobutyl ether), Methyl vinyl ether-maleic anhydride copolymer), styrene-based polymer (styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, sodium polystyrene sulfonate),
Sodium-polyvinylsulfonate], a nitrogen-containing polymer (or a cationic polymer) or a salt thereof (a quaternary ammonium salt such as polyvinylbenzyltrimethylammonium chloride and polydiallyldimethylammonium chloride), polydimethylaminoethyl (meth) acrylate hydrochloride, Polyvinyl pyridine, polyvinyl imidazole, polyethylene imine, polyamide polyamine, polyacrylamide, polyvinyl pyrrolidone, etc.). These hydrophilic polymers can be used alone or in combination of two or more.

Among these hydrophilic polymers, cellulose derivatives (especially hydroxyethyl cellulose), vinyl alcohol polymers (especially polyvinyl alcohol), vinyl ester polymers (especially vinyl acetate copolymer), polyvinyl acetate Pyrrolidone and the like are preferred.

As described later, at least one selected from (1) polyoxyalkylene unit, (2) acetoacetyl group, (3) carboxyl group, (4) acid anhydride group and (5) amino group. Hydrophilic polymers having two functional groups are also preferred.

The vinyl ester polymer (eg, vinyl acetate copolymer) is a copolymer of a vinyl ester (eg, vinyl acetate) and another copolymerizable monomer, and is partially saponified (eg, saponified). Partially saponified product having a degree of hydrolysis of about 10 to 90%). Preferred copolymerizable monomers include a hydrophilic group (for example, a carboxyl group, a sulfonic acid group or a salt thereof, a hydroxyl group, an ether group, and the like).
In particular, a vinyl monomer having an ether group, especially an oxy C _2-4 alkylene unit, for example, the number of units (addition mole) of an alkylene oxide is 1 to 100, preferably 2 to 80 (for example, , 5
~ 80), more preferably 5 ~ 70 (e.g. 10 ~
About 50) (meth) acrylic acid esters and allyl ethers can be used.

(1) In the hydrophilic polymer having a polyoxyalkylene unit, preferred monomers having an oxyalkylene unit include (meth) acrylates, which are vinyl monomers in which the oxyalkylene unit is an oxyethylene unit, especially Oxyalkylene (meth) allyl ether (among others, polyoxyethylene allyl ether) is included.

In the vinyl acetate-based copolymer, the proportion of the copolymerizable monomer can be selected within a range that does not impair the sharpness of an image, and is, for example, 0.1 to 50 mol%, preferably 1 to 30 mol% of the whole monomer. Mol%, more preferably 2.
It is about 5 to 25 mol% (for example, 3 to 20 mol%).

A copolymer of vinyl acetate and a vinyl monomer having a polyoxyalkylene unit (modified vinyl acetate resin) is available from Nippon Synthetic Chemical Co., Ltd. under the trade name "OKS-7158G" or the like. Available.

(2) The acetoacetyl group-containing hydrophilic polymer (acetoacetyl group-modified hydrophilic polymer) contains an acetoacetyl group formed by the reaction of a hydroxyl group-containing hydrophilic polymer with an acetoacetate ester. Examples include hydrophilic polymers, for example, acetoacetyl group-modified vinyl acetate copolymers (acetoacetyl group-containing polyvinyl alcohol, acetoacetyl group-containing cellulose derivatives, and the like). The acetoacetyl group-modified vinyl acetate copolymer can be obtained, for example, from Nippon Synthetic Chemical Industry Co., Ltd.

(3) Hydrophilic polymer having carboxyl group (carboxyl group-modified hydrophilic polymer) (3a) Carboxyl group-modified polyvinyl alcohol, for example, vinyl ester (vinyl acetate, vinyl propionate, vinyl formate, etc.) and carboxyl A portion of a copolymer with a group-containing unsaturated monomer (such as a monocarboxylic acid such as (meth) acrylic acid, a dicarboxylic acid such as maleic acid, fumaric acid, and itaconic acid, or an acid anhydride or monoalkyl ester thereof). Saponified. Such a carboxyl group-modified polyvinyl alcohol can be obtained, for example, from Kuraray Co., Ltd.

The carboxyl group-modified hydrophilic polymer includes, for example, styrene- (meth) acrylic acid copolymer, (meth) acrylate- (meth) acrylic acid copolymer (methyl methacrylate- (meth) acrylic acid). Acid copolymer) and vinyl acetate- (meth) acrylic acid copolymer.

(3b) Carboxyl group-containing polysaccharides such as carboxy C _1-4 alkyl cellulose, carboxymethyl dextran, alginic acid and the like.

(4) Acid anhydride group-containing hydrophilic polymer Alkyl vinyl ether-maleic anhydride copolymer (eg, methyl vinyl ether-maleic anhydride copolymer),
Ethylene-maleic anhydride copolymer, vinyl acetate-maleic anhydride copolymer, styrene-maleic anhydride copolymer, (meth) acrylate-maleic anhydride copolymer (methyl methacrylate-maleic anhydride copolymer) (5) Amino group-containing hydrophilic polymer Polyamide-polyamine, polyvinylamine, poly (N
-Vinylformamide), amino group-containing polysaccharides (aminodextran, chitosan, etc.). A preferred ink image-receiving layer can be composed of a cationic polymer and the hydrophilic polymer. Even such an ink receiving sheet shows high ink absorbency. [Cationic polymer] The cationic monomer constituting the cationic polymer includes various monomers having a tertiary amino group or a base thereof, and a quaternary ammonium group or a quaternary ammonium group. Various monomers capable of forming an ammonium base can be used.

Examples of the cationic monomer include di C
_1-4 alkylamino-C _2-3 alkyl (meth) acrylamide or a salt thereof [dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide or these And di C _1-4 alkylamino-C _2-3
Acrylic monomer such as an alkyl (meth) acrylate or a salt thereof [dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate or a salt thereof, etc.] , Di C _1-4 alkylamino-C _2-3 alkyl group-substituted aromatic vinyl or a salt thereof [4- (2-dimethylaminoethyl) styrene, 4- (2-dimethylaminopropyl) styrene and the like, and salts thereof Etc.], a nitrogen-containing heterocyclic monomer or a salt thereof [vinylpyridine, vinylimidazole,
Vinylpyrrolidone or salts thereof]. Salts include hydrohalides (hydrochlorides, hydrobromides, etc.), sulfates, alkyl sulfates (methyl sulfate, ethyl sulfate, etc.), alkyl sulfonates, aryl sulfonates, carboxylic acids Salts (such as acetates) can be exemplified. The quaternary ammonium base may be generated by reacting an alkylating agent (epichlorohydrin, methyl chloride, benzyl chloride, etc.) with the tertiary amino group.

The cationic polymer may have a crosslinkable group. Cationic polymer having a crosslinkable group,
It may be a polymer of a monomer containing a cationic monomer and at least a crosslinkable monomer among the crosslinkable monomer and the hydrophilic monomer. A preferred cationic polymer can be composed of a monomer polymer containing at least a cationic monomer, a crosslinkable monomer, and a hydrophilic monomer.

The crosslinkable monomers include various monomers having a self-crosslinkable or reactive functional group, for example, epoxy group-containing monomers [glycidyl (meth) acrylate, (meth) allyl glycidyl ether, 1-allyloxy-3,4-epoxybutane, 1- (3-butenyloxy) -2,3-
Epoxy propane, 4-vinyl-1-cyclohexene-
1,2-epoxide and the like], a methylol group-containing monomer or a derivative thereof [N-methylol (meth) acrylamide, N-C _1-4 alkoxymethyl (meth) acrylamide such as N-methoxymethyl (meth) acrylamide,
N-butyrol (meth) acrylamide, etc.], a monomer containing a hydrolyzable condensable group such as a silyl group [vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethoxydimethylsilane, vinylethoxydimethylsilane, vinyl Isobutoxydimethylsilane, vinyldimethoxymethylsilane, vinyldiethoxymethylsilane, vinyltris (β-methoxyethoxy) silane, vinyldiphenylethoxysilane, vinyltriphenoxysilane, γ- (vinylphenylaminopropyl) trimethoxysilane, γ- ( (Vinylbenzylaminopropyl) trimethoxysilane, γ- (vinylphenylaminopropyl) triethoxysilane, γ- (vinylbenzylaminopropyl) triethoxysilane, divinyldimethoxysilane , Divinyldiethoxysilane, divinyldi (β-methoxyethoxy) silane, vinyldiacetoxymethylsilane, vinyltriacetoxysilane,
Vinylbis (dimethylamino) methylsilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyltrichlorosilane, vinylmethylphenylchlorosilane, allyltriethoxysilane, 3-allylaminopropyltrimethoxysilane, allyldiacetoxymethylsilane, allyltriacetoxysilane, Allylbis (dimethylamino) methylsilane, allylmethyldichlorosilane, allyldimethylchlorosilane, allyltrichlorosilane, methallylphenyldichlorosilane, β- (meth) acryloxyethyltrimethoxysilane, β- (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ-
(Meth) acryloxypropyltriethoxysilane, γ
-(Meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldichlorosilane, γ- (meth) acryloxypropyltris (β
-Methoxyethoxy) silane, etc.], aziridinyl group-containing monomer [2- (1-aziridinyl) ethyl (meth) acrylate, 2- (1-aziridinyl) propyl (meth) acrylate, 3- (meth) acrylic acid 3- (1-aziridinyl) propyl and the like]. These crosslinkable monomers can be used alone or in combination of two or more.

Preferred crosslinkable monomers have a hydrolytic condensable group, especially an alkoxysilyl group (C _1-4 alkoxysilyl group such as methoxysilyl group and ethoxysilyl group).

The hydrophilic monomers include, for example, carboxyl group-containing monomers [(meth) acrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid and other free carboxyl groups or acid anhydrides. Monomer having a functional group,
And salts thereof (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.)], unsaturated polycarboxylic acids or acid anhydrides thereof, and linear or branched alcohols having about 1 to 20 carbon atoms. [Monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, mono-2-ethylhexyl maleate, etc.], hydroxyl group-containing monomer [2-hydroxyethyl (meth) acrylate, (meth) 2-hydroxypropyl acrylate, 3- (meth) acrylate
Hydroxypropyl, (meth) acrylic acid hydroxy C _2-6 alkyl ester such as 4-hydroxybutyl (meth) acrylate], amide group-containing monomer [(meth)
Acrylamide, α-ethyl (meth) acrylamide,
N-methyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone (meth) acrylamide, etc.], sulfonic acid group-containing monomers [styrene sulfonic acid, vinyl sulfonic acid, etc.], ether group-containing monomers [ Vinyl methyl ether, vinyl ethyl ether,
Vinyl ethers such as vinyl isobutyl ether],
Examples thereof include copolymerizable monomers having a hydrophilic group such as polyoxyalkylene group-containing monomers [diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, etc.). These hydrophilic monomers can be used alone or in combination of two or more.

Preferred hydrophilic monomers include a carboxyl group-containing monomer [(meth) acrylic acid or a salt thereof (eg, sodium salt, potassium salt, etc.)] and a hydroxyl group-containing monomer [(meth) 2-hydroxyethyl acrylate, hydroxypropyl (meth) acrylate), a monomer having a polyoxyalkylene unit [diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate] Etc.] are included.

These monomers are usually used in combination with a nonionic monomer in order to adjust film formability and film properties.

Nonionic monomers include, for example, alkyl esters [eg, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, (meth)
T-butyl acrylate, hexyl (meth) acrylate,
Octyl (meth) acrylate, 2- (meth) acrylate
(Meth) acrylic acid C such as ethylhexyl, lauryl me (meth) acrylate, stearyl (meth) acrylate
_1-18 alkyl esters, etc.], cycloalkyl esters [cyclohexyl (meth) acrylate, etc.], aryl esters [phenyl (meth) acrylate, etc.], aralkyl esters [benzyl (meth) acrylate, etc.], aromatic vinyls [ Styrene, vinyltoluene, α-methylstyrene, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [allyl acetate, etc.], halogen-containing monomers [vinylidene chloride, vinyl chloride, etc.] ], Vinyl cyanide [such as (meth) acrylonitrile], and olefins [such as ethylene and propylene].

These nonionic monomers can be used alone or in combination of two or more.

Examples of the nonionic monomer include C _1-18 alkyl (meth) acrylate [particularly C _2-10 alkyl acrylate and C _1-6 alkyl methacrylate] and aromatic vinyls. [Especially styrene] and vinyl esters [especially vinyl acetate] are used.

The amount of the cationic monomer, the crosslinkable monomer and the hydrophilic monomer can be selected within a range that does not impair the ink absorbency, the ink fixing property, and the like. 0.1 to 50% by mole of the whole monomer (for example, 1 to 45% by mole), preferably 0.5 to 40% by mole
(For example, 2 to 35 mol%), and more preferably 1 to 3
It is about 0 mol% (for example, 3 to 25 mol%), and usually about 2 to 25 mol%. The amount of the crosslinkable monomer is, for example, 0.1 to 25 mol%, preferably 0.2 to 20 mol%, more preferably 0.5 to 25 mol% of the whole monomer.
It is about 15 mol%, usually about 0.3 to 10 mol%.

The amount of the hydrophilic monomer used is, for example,
0 to 50 mol%, preferably 0 to 45 mol% (0.5 to 45 mol%), more preferably 0 to 40 mol% of the whole monomer
Mol% (1 to 35 mol%), usually 1 to 20 mol%.
It is about mol%. Usually, the remainder of the monomer is composed of the nonionic monomer.

The weight ratio of the monomers is such that the crosslinkable monomer is 1 to 50 parts by weight, preferably about 5 to 20 parts by weight, based on 100 parts by weight of the cationic monomer. The amount of the monomer is about 0 to 300 parts by weight, preferably about 10 to 200 parts by weight, and the amount of the nonionic monomer is about 100 to 1000 parts by weight, preferably about 150 to 500 parts by weight.

The glass transition temperature of the cationic polymer can be selected within a range that does not impair the film-forming properties when measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC). -20 ° C to 50 ° C, preferably -10 ° C to
It is 40 ° C, more preferably about 0 ° C to 30 ° C. The polymer having such a glass transition temperature is obtained by appropriately combining the cationic monomer and the crosslinkable monomer with a hydrophilic monomer and / or a nonionic monomer as required. Can be prepared.

The monomer is usually a hard monomer [for example, a monomer which forms a homopolymer having a glass transition temperature of about 80 to 120 ° C. (particularly 90 to 105 ° C.) such as methyl (meth) acrylate, styrene or the like. Isomers), soft monomers [monomers that form homopolymers having a glass transition temperature of about −85 ° C. to ₋₁₀ ° C. (particularly −85 ° C. to −20 ° C.) such as C _2-10 alkyl acrylate], and the like. In many cases, a copolymer is constituted by combining with a nonionic monomer.

The ratio of the hard monomer to the soft monomer is, for example, the former / the latter = 5/95 to 95/5 (weight ratio), preferably 20/80 to 80/20 (weight ratio), and more preferably 30/80. / 70 to 70/30 (for example, 40/60 to 60/40) (weight ratio).

When the above monomers are combined, the ratio of each monomer can be selected, for example, from the following range.

(A) 1 to 40% by weight (preferably 3 to 35% by weight, particularly 5 to 5% by weight) of a cationic monomer
(B) crosslinkable monomer 0.5 to 20% by weight (preferably 1 to 15% by weight, particularly 2% by weight)
(C) hydrophilic monomer 0 to 50% by weight (preferably 2 to 45% by weight, particularly 5 to 4% by weight)
0% by weight) (d) Hard monomer 10 to 60% by weight (preferably 20 to 55% by weight, especially 25 to 50% by weight) (e) Soft monomer 10 to 60% by weight (preferably 15 to 50% by weight, especially (20 to 45% by weight) The average particle diameter of the polymer particles in the cationic emulsion containing the cationic polymer is, for example, about 1 to 200 nm, preferably about 3 to 100 nm, and more preferably about 5 to 50 nm.

The cationic emulsion containing such a cationic polymer is emulsion-polymerized with a conventional method, for example, an emulsion polymerization system containing a nonionic surfactant and / or a cationic surfactant. The method can be obtained by, for example, a method, a method of forming an aqueous emulsion by forming a tertiary amine salt or a quaternary ammonium salt after polymerizing the monomer.

Depending on the reactive functional group of the cationic polymer (for example, an epoxy group such as a glycidyl group, an alkoxysilyl group, etc.), the hydrophilic polymer having a functional group that reacts with the functional group may be selected. Such a hydrophilic polymer can be, for example, in the following combination depending on the type of a reactive group (particularly a crosslinkable group) of the cationic polymer.

Cationic polymer: epoxy group such as glycidyl group Hydrophilic polymer: carboxyl group, acid anhydride group, amino group Cationic polymer: methylol group Hydrophilic polymer: hydroxyl group, carboxyl group, acid anhydride Group Cationic polymer: Hydrolytic condensation group such as alkoxysilane group Hydrophilic polymer: hydroxyl group, carboxyl group Cationic polymer: aziridinyl group Hydrophilic polymer: hydroxyl group, carboxyl group, amino group Such combination In this case, the cationic polymer and the hydrophilic polymer are bonded or cross-linked to form an ink image-receiving layer having high ink absorbency, ink fixability and printability.

Preferred hydrophilic polymers having reactivity with the cationic polymer include a self-crosslinkable hydrophilic polymer having a functional group reactive with the reactive functional group of the cationic polymer. Examples of the polymer include hydrophilic polymers such as the above-mentioned acetoacetyl group-modified hydrophilic polymer, carboxyl group-modified hydrophilic polymer, acid anhydride group-containing hydrophilic polymer, and amino group-containing hydrophilic polymer. .

The ratio between the cationic polymer and the hydrophilic polymer does not impair the ink absorbency or ink fixing property depending on the type of the cationic polymer or hydrophilic polymer, the concentration of the crosslinkable group, and the like. Range, for example, in terms of solids, the former / the latter = 5/95 to 95/5 (% by weight), preferably 10/9
0 to 90/10 (% by weight), more preferably 20/8
It can be selected from a range of about 0 to 80/20 (% by weight), and is usually 10/90 to 50/50 (% by weight), particularly 20/8.
It is about 0 to 40/60 (% by weight).

[0066] Contrary to the above, the hydrophilic polymer may have a reactive group having reactivity with the reactive functional group of the cationic polymer. For example, when the hydrophilic polymer is an epoxy group-containing polymer, the cationic polymer may have a carboxyl group or an amino group. Epoxy group-containing polymers include, for example, hydrolysis of a copolymer of an epoxy group-containing monomer (such as glycidyl (meth) acrylate or allyl glycidyl ether) and a vinyl ester (such as vinyl acetate), active hydrogen atoms (such as , A hydroxyl group, an amino group, a carboxyl group, etc.) and an epoxy group-containing polyvinyl alcohol having an epoxy group formed by the reaction of epichlorohydrin with the hydrophilic polymer having the epoxy group, or copolymerization of the epoxy group-containing monomer with vinylpyrrolidone. The resulting epoxy group-containing polyvinylpyrrolidone is included. The content of the epoxy group is 0.01 to 5 mol%, preferably 0.1 to 5 mol%, based on the whole monomer.
It is about 1 to 3 mol% (for example, 0.2 to 2.5 mol%), particularly about 0.2 to 2 mol%.

[0067] A particulate lubricant may be added to the ink image receiving layer. By adding the particulate lubricant, blocking can be prevented and the slipperiness of the sheet can be improved. Also, after the image is formed, even if it comes into contact, the image can be prevented from falling off, writing can be performed, and even when the ink receiving sheet is overlaid,
Adhesion between sheets can be prevented. [Lubricant] As the lubricant, a particulate inorganic lubricant, organic lubricant and the like can be used. Inorganic lubricants include silica, alumina, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, magnesium aluminosilicate, kaolin, clay, talc, diatomaceous earth, wollastonite, calcined siliceous earth, etc. Mineral particles such as sericite; carbonaceous particles such as white carbon; zinc oxide;
Metal oxides such as titanium oxide, magnesium oxide, calcium oxide and barium oxide; carbonates of metals such as calcium carbonate, magnesium carbonate, barium carbonate and zinc carbonate; sulfates of metals such as magnesium sulfate, calcium sulfate and barium sulfate; Metal hydroxides such as aluminum hydroxide, calcium hydroxide, and magnesium hydroxide; zeolites (such as synthetic zeolites);

In cases where high transparency is required, such as for OHP sheets, organic lubricants are preferred. Examples of organic lubricants include amino resins, polyethylene resins, polystyrene resins, acrylic resins (such as (meth) acrylates such as methyl methacrylate), urea resins, melamine resins, polyamide resins, benzoguanamine resins, silicone resins, and fluorine resins. And organic particles such as fine hollow particles and the like. One or more of these powders may be appropriately selected and used together.

The shape of the lubricant is not particularly limited, and may be spherical, polygonal or irregular.

The average particle size of the lubricant can be selected according to the intended use of the sheet. However, when a highly transparent ink image-receiving sheet is obtained, the average particle size is about 0.1 to 50 μm, preferably 0.2 to 50 μm.
５０50 μm (for example, 0.25 to 40 μm), and usually 0.25 to 30 μm (for example, 0.25 to 2 μm).
5 μm).

The ratio of the particulate lubricant is about 0.1 to 10 parts by weight (for example, 0.2 to 8 parts by weight), preferably 0.5 to 0.5 parts by weight, based on 100 parts by weight of the total components of the ink image receiving layer.
About 5 parts by weight (for example, 0.5 to 2 parts by weight).
If the proportion of the particulate lubricant is less than 0.1 part by weight, the effect of improving the blocking resistance is small, and if it exceeds 10 parts by weight, the strength of the ink image-receiving layer tends to decrease.

When a lubricant is combined with a polymer having an alkoxysilyl group as a cationic polymer (a cationic polymer using an alkoxysilyl group-containing crosslinkable monomer), the reactivity of the alkoxysilyl group is utilized. Thus, the bonding with the lubricant can be enhanced, and the lubricant can be effectively prevented from falling off. The ratio of the lubricant is 10 to 15 parts by weight per 100 parts by weight of the alkoxysilyl group-containing polymer (in terms of monomer).
0 parts by weight, preferably 20 to 120 parts by weight, more preferably about 40 to 100 parts by weight.

A curing agent (curing catalyst or curing accelerator) may be added to the ink image-receiving layer, if necessary, to accelerate the curing reaction. Examples of the curing agent include an organic tin compound, an organic aluminum compound, an organic titanium compound, an organic zirconium compound, an acidic compound, an acidic phosphate, and a mixture or a reaction product of the acidic phosphate and an amine. These curing agents can be used alone or in combination of two or more.

The amount of the curing agent used is within a range capable of promoting the curability, for example, 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the hydrophilic polymer in terms of solid content.
It is about parts by weight.

Further, in order to improve the fixability of the colorant (dye), it is advantageous to use a dye fixing agent, especially a high molecular dye fixing agent. The dye fixing agent (polymer dye fixing agent)
Usually, a cationic group (particularly, guanidyl group or
Quaternary ammonium salt type strong cation group).
The dye fixative may be water-soluble.

Examples of the dye fixing agent include dicyan fixing agents (eg, dicyandiamide-formalin polycondensate), polyamine fixing agents [for example, aliphatic polyamines such as diethylenetriamine, triethylenetetramine, dipropylenetriamine and polyallylamine, and phenylenediamine]. Such as aromatic polyamines, condensates of dicyandiamide and (poly) C _2-4 alkylene polyamine (eg, dicyandiamide-diethylenetriamine polycondensate), and polycationic fixing agents. Examples of the polycationic fixing agent include, for example, epichlorohydrin-di C
_1-4 alkylamine addition polymer (epichlorohydrin-
Dimethylamine addition polymer, etc.), polymer of allylamine or a salt thereof (polymer of polyallylamine or a hydrochloride thereof, for example, Nitto Boseki Co., Ltd., PAA-10C, PAA-HCl-3L,
PAA-HCl-10L, etc.), a polymer of diallyl C _1-4 alkylamine or a salt thereof (a polymer of diallylmethylamine or a hydrochloride thereof, for example, Nitto Boseki Co., Ltd., PAS-M-1), diallyldiamine Polymers of C _1-4 alkyl ammonium salts (polymers of diallyl dimethyl ammonium chloride, such as Nitto Boseki Co., Ltd., PAS-H-5L, PAS-H-10L, etc.), and diallylamine or a salt thereof with sulfur dioxide Copolymer (diallylamine hydrochloride-sulfur dioxide copolymer, such as Nitto Boseki Co., Ltd., PAS-92), diallyl di C _1-4 alkylammonium salt-sulfur dioxide copolymer (diallyldimethylammonium chloride-sulfur dioxide) Copolymers, for example, Nitto Boseki Co., Ltd., PAS-A-1,
PAS-A-5, PAS-A-120L, PAS-A-120A, etc.), copolymer of diallyldi C _1-4 alkylammonium salt and diallylamine or a salt or derivative thereof (diallyldimethylammonium chloride-diallylamine hydrochloride derivative) Copolymer, for example, Nitto Boseki Co., Ltd., PAS-880),
Diallyl di C _1-4 alkyl ammonium salt polymer, di C
Polymer of _1-4 alkylaminoethyl (meth) acrylate quaternary salt, diallyldi C _1-4 alkylammonium salt-
Acrylamide copolymer (diallyldimethylammonium chloride-acrylamide copolymer, for example, Nitto Boseki Co., Ltd., PAS-J-81), amine-carboxylic acid copolymer (for example, Nitto Boseki Co., Ltd., PAS-410) Etc.) can be exemplified. These dye fixing agents may be used alone or in combination of two or more.

The amount of the dye fixing agent used is within a range in which the fixing property can be improved, for example, in terms of solid content, 0.1 to 100 parts by weight of the resin composition composed of the cationic polymer and the hydrophilic polymer. It can be selected from a range of about 40 to 40 parts by weight, preferably about 1 to 30 parts by weight, more preferably about 2 to 20 parts by weight.

In the ink image receiving layer, if necessary, other components, for example, an aqueous emulsion containing polymer particles (for example, an acrylic resin emulsion, an ethylene-vinyl acetate copolymer emulsion, a vinyl acetate emulsion, etc.). You may make it contain.

The ink image-receiving layer may further contain a conventional additive such as an antifoaming agent, a coating improver,
Thickeners, stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), antistatic agents and the like may be added.

The thickness of the ink image receiving layer can be selected according to the intended use, for example, 1 to 50 μm (for example, 5 to 30 μm),
It is preferably about 10 to 30 μm, usually 5 to 30 μm.
It is about μm.

Since the ink receiving sheet of the present invention is provided with the ink receiving layer, the ink absorbing property and the ink fixing property are high, and the printing property is remarkably improved. Further, since the ink image-receiving sheet uses a stretched styrene resin sheet as a base material, it has high transparency, and its visible light transmittance is 85 to 95%, usually about 88 to 90%.

[Production Method] The ink image-receiving sheet of the present invention can be produced by forming an ink image-receiving layer containing at least the above-mentioned components on at least one surface of the base sheet.

The ink image receiving layer is formed by applying a coating solution prepared using an appropriate solvent (water, a hydrophilic solvent which may be water-soluble, a hydrophobic solvent or a mixed solvent thereof) to a support. it can. When the ink image receiving layer is composed of a hydrophilic polymer and a cationic polymer, and the cationic polymer is in the form of an aqueous emulsion, an aqueous coating solution is used. The coating solution is formed by a conventional casting or coating method, such as a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater, a comma coater, a gravure coater, a silk screen coater method, or the like. Is cast or applied.

The ink image-receiving layer can be formed by applying a coating solution containing the above-mentioned components and the like to at least one surface of the substrate and drying. Further, if necessary, after applying the coating liquid, the ink image-receiving layer may be formed by heating at an appropriate temperature selected from the range of about 50 to 150 ° C. and cross-linked by the cross-linkable group.

A porous layer, an anti-blocking layer, a lubricating layer, an antistatic layer and the like may be formed on the ink receiving layer, if necessary.

The ink image receiving sheet of the present invention is useful as an ink image receiving sheet of an ink jet system for recording by flying small ink droplets, but it is a sheet for printing such as offset printing and flexographic printing (particularly a sheet for aqueous ink). It can also be used as such.

[0087]

According to the present invention, an ink image-receiving layer composed of at least a hydrophilic polymer is formed on at least one surface of a stretched styrene resin sheet.
Ink fixability and printability can be improved to a high degree, and even a plastic sheet can be easily torn (shredded) by a shredder or the like. Further, it can be advantageously used for applications requiring high transparency, such as for overhead projectors (OHP). Further, when the ink image-receiving layer contains a particulate lubricant, it is difficult for the image to fall off due to contact between sheets or the contact with the user's hand or clothes (especially for the image immediately after printing). Also, blocking between sheets can be prevented.

[0088]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the examples, "parts" indicates parts by weight.

The base sheet, hydrophilic polymer, cationic polymer, and lubricant used in Examples, Comparative Examples and Reference Examples are as follows.

1. Base sheet (a-1): Stretched polystyrene sheet (manufactured by Daicel Chemical Industries, Ltd., OPS sheet G90, thickness 130 μm) (a-2): Polyethylene terephthalate film (manufactured by Diafoil Hoechst Co., Ltd., T-100) , Thickness 100
μm) 2. Hydrophilic polymer (b-1): polyoxyalkylene-modified polyvinyl alcohol (OKS-7158, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
G) 3. Cationic polymer (c-1): Cationic acrylic copolymer emulsion 1 Isopropyl alcohol (IPA) 219 was placed in a 2000 ml reaction vessel equipped with a stirrer, reflux condenser, dropping funnel, nitrogen inlet tube and thermometer. And 1.23 parts of azoisobutyronitrile (AIBN), and stir to dissolve.
Warmed to ° C.

As copolymerization components, 93.7 parts of methyl methacrylate (MMA) and n-butyl acrylate (B
A) 98.7 parts, diethylaminoethyl methacrylate (DEAEMA) 49.3 parts and trimethoxysilane propyl methacrylate (Nihon Unicar Co., Ltd., A
-174, hereinafter sometimes simply referred to as A-174)
4.93 parts were mixed and dropped into the flask over about 4 hours. After the addition, AIBN 0.25 was added as an additional catalyst.
And a solution of 25 parts of IPA was added dropwise, and the reaction was further continued for 2 hours to complete the polymerization.

After completion of the polymerization, acetic acid 16
Then, 705 parts of water was added dropwise over about 2 hours to emulsify. After emulsification, IPA was evaporated using a rotary evaporator to obtain a cationic acrylic copolymer emulsion (c-1) (solid content: 34.7%).

(C-2): Cationic acrylic copolymer emulsion 2 As copolymer components, 71.6 parts of MMA, 71.6 parts of BA
Parts, 49.3 parts of DEAEMA, polyethylene glycol methacrylate (Blenmer PEG manufactured by NOF Corporation)
-200, hereinafter simply referred to as PEG-200) in the same manner as (c-1) except that 49.3 parts and 4.9 parts of "A-174" were used. 2) was obtained (solids concentration: 31.9).
%).

4. Lubricant (d-1): polymethyl methacrylate particles (Techpolymer MBX-20, manufactured by Sekisui Chemical Co., Ltd., particle size 20 μm)
m) (d-2): Silica particles (FK-3, manufactured by Degusa)
(10, particle size: 0.3 μm) The evaluation methods of various characteristics of the ink image-receiving sheets obtained in Examples, Comparative Examples and Reference Examples are as follows.

(Tear strength) Width 50 mm, length 150 m
In the film of m, a slit of 75 mm was formed in the length direction from the center in the width direction to obtain a test piece.

The test piece was subjected to JIS K7128
The tear strength was measured at a test speed of 200 mm / min using a universal tensile tester in accordance with Method A (Trouser tear method) of a tear test method for plastic films and sheets.

Using an ink jet printer (manufactured by Canon Inc., BJC-420J), each color of cyan, yellow, magenta, and black was printed solidly on the ink receiving sheets obtained in Examples and Comparative Examples. A recorded image was formed.

(Ink Absorption) After printing, place a PPC copy sheet on the print unit at regular intervals, press down on the copy sheet with a finger for 5 seconds, peel off the copy sheet, and check for ink set-off. Was visually determined, and the ink absorbency was evaluated by the time until set-off was not observed.

(Printing condition) The printing condition was visually evaluated based on the following criteria.

○ The printed area is printed uniformly. △ Some unevenness is observed in the printed area. X Significant unevenness is observed in the printed area. The swab was rubbed 5 times with a swab and the ink fixing property (image detachment) was evaluated according to the following criteria.

○ The image is hardly dropped. × The image is easily dropped. Examples 1 and 2 According to the combination shown in Table 1, 30 parts of a solid content of a cationic polymer and 700 parts of a 10% by weight aqueous solution of a hydrophilic polymer ( (Solid content 70 parts) and 1 part by weight of the particulate lubricant (d-1) were mixed to obtain an aqueous coating liquid.

A base sheet having a thickness of 130 μm (a-1)
To form an ink image receiving layer having a thickness of 15 μm by applying the aqueous coating liquid and drying at 100 ° C. for 3 minutes.
An ink receiving sheet was obtained. The obtained sheet was evaluated for tear strength, ink absorbency, printing state, and ink fixability as described above. Table 1 shows the results.

Examples 3 and 4 Sheets were prepared and evaluated in the same manner as in Example 1 except that 3 parts by weight of silica particles (d-2) were used as the particulate lubricant. Table 1 shows the results.

Example 5 A sheet was prepared in the same manner as in Example 1 except that the cationic polymer was not used and 1000 parts (solid content: 100 parts) of a 10% by weight aqueous solution of a hydrophilic polymer was used. An evaluation was performed. Table 1 shows the results.

Comparative Examples 1 and 2 Example 1 except that a polyethylene terephthalate film (a-2) having a thickness of 100 μm was used as a base sheet.
A sheet was prepared in the same manner as in Examples 2 and 3, and the same evaluation was performed.
Table 1 shows the results.

Comparative Example 3 A sheet was prepared in the same manner as in Comparative Example 1 except that the cationic polymer was not used and 1000 parts (solid content: 100 parts) of a 10% by weight aqueous solution of a hydrophilic polymer was used. An evaluation was performed. Table 1 shows the results.

Comparative Example 4 A sheet was prepared and evaluated in the same manner as in Comparative Example 1 except that no particulate lubricant was used. Table 1 shows the results.

Reference Example 1 The same evaluation as in Example 1 was performed three times for the base sheet (a-1) alone, and the average of the three measurements was calculated to determine the tear strength. Table 1 shows the results.

Reference Example 2 The substrate sheet (a-2) was heat-treated at 100 ° C. for 3 minutes.
Evaluation was performed in the same manner as in Reference Example 1. Table 1 shows the results.

[0111]

[Table 1]

As is evident from Table 1, the ink receiving sheets obtained in the examples were higher in ink absorbability and printability than the comparative examples. In addition, the tear strength was small, and shredding with a shredder was easy. In the case of the polyethylene terephthalate film of the comparative example, the film was jammed and could not be shredded even when subjected to a shredder. In Comparative Example 4 in which no lubricant was added, the ink absorbency was reduced. Furthermore, the ink receiving sheet of the example had good writability with water-based magic, and the image was less likely to fall off than the polyethylene terephthalate film even when the image portion was touched by hand after writing.

Claims (18)

[Claims] 1. An image receiving sheet having an ink image receiving layer formed on at least one surface of a substrate sheet, wherein the substrate sheet is composed of a stretched styrene resin sheet. 2. The ink image-receiving sheet according to claim 1, wherein the stretched styrene-based resin sheet is tearable. 3. The tear strength of the substrate sheet is 0.05 to 0.05.
2. The ink image receiving sheet according to claim 1, wherein the value is 0.25 kgf / mm. 4. A stretched styrene resin sheet having a thickness of 130 μm.
Tear strength S _STIs a 100μm thick polyethylene
Tear strength S of terephthalate film_{PE T}Against
And the tear strength ratio S_ST/ S_PET= 0.01 / 1 to 0.7
2. The ink image-receiving sheet according to claim 1, wherein 5. The ink image-receiving sheet according to claim 1, wherein the stretch ratio of the stretched styrene resin sheet is 1.5 to 3 times in the machine direction and 1.5 to 3 times in the transverse direction. 6. The stretched styrene resin sheet has a thickness of 30.
The ink image-receiving sheet according to claim 1, which has a thickness of from about 500 m to about 500 m. 7. The ink image receiving sheet according to claim 1, wherein the ink image receiving layer contains at least a hydrophilic polymer. 8. The ink image-receiving sheet according to claim 1, wherein the ink image-receiving layer comprises a cationic polymer and a hydrophilic polymer. 9. The ink image receiving sheet according to claim 1, wherein the ink image receiving layer comprises a cationic polymer having a crosslinkable group and a hydrophilic polymer. 10. The ink image-receiving sheet according to claim 9, wherein the cationic polymer is a polymer composed of a cationic monomer and a crosslinkable monomer having an alkoxysilyl group. 11. The ink image-receiving sheet according to claim 10, wherein the cationic polymer is a polymer further composed of a hydrophilic monomer. 12. The ink image receiving sheet according to claim 11, wherein the hydrophilic monomer is a (meth) acrylate having a polyoxyalkylene unit. 13. The ink image-receiving sheet according to claim 1, wherein the ink image-receiving layer further contains a particulate lubricant. 14. The ink receiving sheet according to claim 13, wherein the lubricant has an average particle size of 0.1 to 50 μm. 15. The ink image-receiving sheet according to claim 13, wherein the ink image-receiving layer contains 0.1 to 10 parts by weight of a lubricant based on 100 parts by weight of the total components of the ink image-receiving layer. 16. The ink image-receiving layer contains 10 to 150 parts by weight of a lubricant based on 100 parts by weight (in terms of monomer) of a cationic polymer having an alkoxysilyl group.
3. The ink receiving sheet according to item 3. 17. The tear strength of the substrate sheet is 0.08 to
0.2 kgf / mm, wherein the ink image-receiving layer is an ink image-receiving sheet comprising a cationic polymer, a hydrophilic polymer and a particulate lubricant, wherein the lubricant has an average particle size of 0.2
The ink image-receiving sheet according to claim 1, wherein the ratio of the lubricant is 0.2 to 8 parts by weight based on 100 parts by weight of the total amount of the components of the ink image-receiving layer. 18. A method for producing an ink image receiving sheet, wherein an ink image receiving layer is formed on at least one surface of a stretched styrene resin sheet.