JP2001001636A - Sheet for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet for ink jet recording which is free from a bleeding failure to in a printer while keeping the superb glossiness of an ink receptive layer using inorganic silica particulates and excellent printing property. SOLUTION: In the sheet for ink jet recording having at least one ink receptive layer formed on a water-resistant support, the ink receptive layer comprises a porous layer containing inorganic fine grains whose average primary particle dia. is 20 nm or less. In addition, the surface electric resistance of the ink receptive layer is 1×1011 Ω or less under conditions of 20 deg.C and 65%RH and the surface electric resistance of the back face of the water-resistant support is 1×1011 Ω or less under conditions or 20 deg.C and 65%RH.

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 which not only has excellent quick-drying properties, water resistance, ink absorbency and glossiness but also does not cause a paper passing failure in a printer.

[0002]

2. Description of the Related Art As a recording sheet used in an ink jet recording system, a pigment such as amorphous silica is coated with a water-soluble binder such as polyvinyl alcohol on a support which is usually called a paper or an ink jet recording sheet. A recording sheet provided with a porous ink absorption layer is known.

[0003] For example, Japanese Patent Application Laid-Open No. 55-51583,
Nos. 6-157, 57-107879, 57-10
No. 7880, No. 59-230787, No. 62-160
No. 277, No. 62-184879, No. 62-1833
No. 82, 64-11877, etc., a recording sheet obtained by applying a silicon-containing pigment such as silica to a paper support together with an aqueous binder has been proposed.
Since these recording sheets are made of paper as a support, there is no problem with the paper passing property in the printer, but there is no water resistance, and the image quality,
The gloss was also low.

Japanese Patent Publication No. 3-55552, Japanese Patent Application Laid-Open No. 2-18 / 1990
No. 8287 discloses a layer having a large number of voids (voids) in which an ink receiving layer absorbs and retains ink by using ultrafine silica particles synthesized by a gas phase method (hereinafter, referred to as fumed silica). Layer, porous layer)
A technique for increasing the ink absorbency of a recording sheet is disclosed. The use of these fine silica particles dramatically improved image quality and gloss, but still had a problem in water resistance.

[0005] Organic water-soluble cationic polymers for fixing a water-soluble ink to an ink receiving layer in order to improve water resistance are known. For example, Japanese Unexamined Patent Publication No. 60-49990
No. 60-83882, No. 61-58788
No. 62-174184, and the official gazette. The combined use of these organic water-soluble cationic polymers and inorganic fine particles such as silica is generally performed and known. When an organic water-soluble cationic polymer is added for the purpose of improving water resistance, it can be said that the ink does not bleed due to water or high humidity. At the present time, the strength is reduced and a problem occurs in practical use.

JP-A-6-64306, JP-A-9-32
No. 3475, JP-A-10-175365, JP-A-11-175
It has been proposed to use a water-resistant support similar to a resin-coated paper used as a photographic base paper in which both sides of a base paper are coated with a resin as described in Examples of No. -20306. When an ink-jet receiving layer containing gelatin described in JP-A-6-64306 is applied, since the resin-coated paper is used for the support, the ink-receiving layer has water resistance. It is not water resistant because it melts. JP-A-8-174992, JP-A-9
JP-A-323475, JP-A-10-100377, JP-A-10-175365, JP-A-10-193776
No., JP-A-11-20300, JP-A-11-3448
No. 1 proposes an invention in which an ink jet receiving layer containing inorganic fine particles is applied to resin-coated paper to achieve both printability and water resistance. The water resistance of the inkjet paper has been significantly improved by these combinations and has been satisfactory.However, the water-resistant support used is covered during normal handling because it is coated on both sides with an insulating polyolefin. It is easily charged due to the friction or the like. This charging easily occurs even if the ink jet receiving layer is applied to the surface. Once charged, the charge does not easily disappear and the inkjet paper and the inkjet paper are attracted electrostatically. When performing continuous printing with an inkjet printer, the paper is not sent one by one, but double feed is sent simultaneously. It is the present situation that causes a phenomenon and is a problem.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording sheet which is not only excellent in quick drying, water resistance, ink absorbency and glossiness but also does not cause a paper passing failure in an ink jet printer. To provide.

[0008]

The object of the present invention is to provide an ink jet recording sheet having at least one ink receiving layer on a water-resistant support, wherein the ink receiving layer has an average primary particle diameter of 20 nm or less. Wherein the ink receiving layer has a surface electric resistance of 1 × 10 ¹¹ Ω or less at 20 ° C. and 65% RH, and further comprises a back surface of the water-resistant support. Has a surface electric resistance of 1 × 10 ¹¹ Ω or less at 20 ° C. and 65% RH.

The use of inorganic fine particles for the ink receiving layer is known as described above. Particularly preferred inorganic fine particles include fumed silica or alumina hydrate. In particular, fine particles having an average primary particle size of 20 nm or less are generally used for fumed silica. Since these inorganic fine particles are fine particles, a glossy surface can be obtained, and high image quality can be obtained. On the other hand, since the surface is high gloss, the frictional resistance of the surface is large, and an ink jet printer is required.
When printing more than one sheet of paper continuously, it is necessary to perform processing such as matting the back surface to reduce the frictional resistance between the front and back surfaces in order to smoothly transport the inkjet paper to the printing unit one by one. . JP-A-6-64306, JP-A-9-64306
JP-A-323475, JP-A-10-175365, JP-A-11-20306, etc. The resin-coated paper used as a photographic base paper in which both sides of the base paper are coated with resin as described in the examples, etc. The surface of the resin layer is matted. Further, Japanese Patent Application Laid-Open No. 10-17536
As described in the example of No. 5, Tg = 65 on the back surface
Acrylic latex at 0.6 ° C. and 0.6 g of 13 μm silica matting agent are applied to further reduce frictional resistance. Although the treatment for reducing the frictional resistance between the front and back surfaces has a certain effect, it is still inadequate and an improvement is desired. The inventors of the present invention have found that not only the friction resistance of the back surface but also the surface electric resistance of the ink receiving layer and the surface on the opposite side (hereinafter referred to as the back surface) are important for the paper feeding failure in the ink jet printer. In other words, it has been found that when a sheet for ink jet recording is charged with static electricity, a sheet passing defect occurs in which two or more sheets are fed at a time when a sheet for ink jet recording is charged with static electricity. The most effective method for reducing the charging of the ink jet recording sheet is to lower the surface electric resistance as in the present invention. As described in Examples of JP-A-8-174992, aluminum oxide (aluminasol 100, manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex O, Nissan Chemical Industries, Ltd.) are used as antistatic agents on the back surface. )) Is dispersed in water at a weight ratio of 1/2 (aluminazole 100 / Snowtex O) and the weight after drying is 0.2 g / m ^2.
Although the application is performed so as to reduce the surface electric resistance of the back surface to reduce the charge, it is not sufficient.
The present inventors have studied in more detail and found that even if the surface electric resistance of only one of the ink receiving layer and the back surface is reduced, a sufficient effect is not recognized, and the ink receiving layer and the back surface can both reduce the surface electric resistance. Importantly, it has been found that this effect can provide an ink jet recording sheet that does not cause a paper passing failure in an ink jet printer. In addition,
The occurrence of paper passing failure in this ink jet printer occurs more remarkably when the ink receiving layer contains the inorganic fine particles than when the water-soluble polymer containing no inorganic fine particles is applied. Was.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The inorganic fine particles having an average primary particle diameter of 20 nm or less used in the present invention are not particularly limited, but synthetic silica or alumina hydrate can be preferably used. The average particle size of the primary particles of the inorganic fine particles used in the present invention is 20 nm.
Or less, preferably 3 to 10 nm, and a specific surface area by BET method of 200 m ² / g or more, preferably 25 m ² / g or more.
0 to 500 m ² / g. The BET method referred to in the present invention is one of the methods for measuring the surface area of a powder by a gas phase adsorption method, and is a method for determining the total surface area of 1 g of a sample, that is, the specific surface area, from an adsorption isotherm. Usually, nitrogen gas is often used as the adsorbed gas, and the method of measuring the amount of adsorption from the change in pressure or volume of the gas to be adsorbed is most often used. The most prominent to represent the isotherm for multimolecular adsorption is
This is a formula of Brunauer, Emmett, Teller, called a BET formula, which is widely used for determining the surface area. The surface area is obtained by calculating the amount of adsorption based on the BET formula and multiplying the area occupied by one adsorbed molecule on the surface.

The synthetic silica preferably used in the present invention includes those obtained by a wet method and those obtained by a gas phase method. Usually, silica fine particles often refer to wet process silica.
As wet silica, silica sol obtained by metathesis of sodium silicate with an acid or the like through an ion exchange resin layer, or colloidal silica obtained by heating and aging this silica sol, gelling silica sol, and changing the production conditions Silicic acid such as silica gel in which primary particles of several microns to 10 microns have become siloxane-bonded three-dimensional secondary particles, and those obtained by heating and producing silica sol, sodium silicate, sodium aluminate, etc. And the like.

The fumed silica more preferably used in the present invention is also called a dry method with respect to a wet method, and is generally produced by a flame hydrolysis method. Specifically, a method of making silicon tetrachloride by burning it with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane may be used alone or in a silicon tetrachloride. And can be used in a mixed state. The fumed silica is commercially available from Nippon Aerosil Co., Ltd., Tokuyama Co., and the like, and can be obtained.

The feature of the fumed silica which is preferably used among the inorganic fine particles in the present invention is that the primary particles are connected in a network structure or a chain and are present in a secondary aggregated state. Thereby, high ink absorbency can be obtained. The state of the secondary aggregation is preferably maintained at about 50 to 500 nm, whereby high ink absorbability can be obtained without reducing gloss.

Examples of the alumina hydrate (cationic alumina hydrate) preferably used in the present invention include JP-A-60-232990 and JP-A-60-245588.
JP-B-3-24906, JP-A-6-199035
JP-A-7-82694 discloses an ink jet recording medium in which fine pseudo-boehmite alumina hydrate is coated on a support surface together with a water-soluble binder. Examples of alumina hydrate include Cataloid AS-1, Cataloid AS-2 and Cataloid AS-3.
Alumina sol 100, Alumina sol 200, Alumina sol 520 (More than Nissan Chemical Industry), M-200 (More than Mizusawa Chemical Industry), Aluminum sol 10, Aluminum sol 20, Aluminum sol 132, Aluminum sol 132S (Alumina sol) SH5, aluminum sol CSA5
5. Aluminum sol SV102 and aluminum sol SB52 (all manufactured by Kawaken Fine Chemical) are commercially available.

The alumina hydrate used in the present invention can be represented by the following general formula. Al2O3 · nH
₂ O-alumina hydrate is composed of dipsite, vialite, norstrandite, boehmite, boehmite gel (pseudo-boehmite), diaspore,
It is classified as amorphous amorphous. Among them, in the above formula, n
Is 1 when it represents a boehmite-structured alumina hydrate, when n is more than 1 and less than 3, it represents a pseudo-boehmite-structured alumina hydrate, and when n is 3 or more, it has an amorphous structure. Represents alumina hydrate. In particular, alumina hydrates preferred for the present invention are those having a pseudo-boehmite structure in which at least n is more than 1 and less than 3.

In the present invention, the amount of the inorganic fine particles contained in the ink receiving layer is preferably at least 8 g / m ² ,
The range is more preferably from 30 to 30 g / m ² .

The ink receiving layer containing the inorganic fine particles is
It is preferable to have a binder in order to maintain the properties as a film. As the binder, various known binders can be used, but a hydrophilic binder which has high transparency and can obtain higher permeability of the ink is preferably used. In the use of the hydrophilic binder, it is important that the hydrophilic binder does not swell at the initial penetration of the ink and does not close the voids.From this viewpoint, a hydrophilic binder having a relatively low swelling property at around room temperature is preferable. Used. Particularly preferred hydrophilic binders are fully or partially saponified polyvinyl alcohols or cationically modified polyvinyl alcohols.

Particularly preferred among polyvinyl alcohols are those partially or completely saponified with a saponification degree of 80 or more. Polyvinyl alcohol having an average degree of polymerization of 200 to 5000 or less is preferred.

As the cation-modified polyvinyl alcohol, for example, as described in JP-A-61-10483, a primary to tertiary amino group or a quaternary ammonium group is added to the main chain or side chain of polyvinyl alcohol. It is a polyvinyl alcohol contained therein.

Further, other hydrophilic binders can be used in combination, but the content is preferably 20% by weight or less based on polyvinyl alcohol. The amount of the hydrophilic binder used together with the inorganic fine particles is 50% by weight or less, preferably 30 to 10% by weight, based on the inorganic fine particles.

In the present invention, the ink receiving layer containing the inorganic fine particles may be further coated with a conventionally known cationic polymer other than this polymer, for example, a polydiallylamine derivative cationic polymer, a dicyandiamide derivative, a polyalkylene polyamine derivative, a polyamine derivative or the like. By including a cationic polymer having a degree of grading of 30% or more, preferably 50% or more, the water resistance (for example, high humidity bleeding) of the ink receiving layer can be further improved. The molecular weight of the cationic polymer is preferably 5,000 or more, more preferably about 5,000 to 100,000. Further, a water-soluble metal salt can be contained for the purpose of improving the water resistance of the ink receiving layer. Examples of these water-soluble metal salts include water-soluble aluminum compounds, water-soluble zirconium compounds, and water-soluble titanium compounds. These water-soluble metal salts can be used in combination with the above cationic polymer.

The ink receiving layer in the present invention preferably contains various oil droplets in order to improve the brittleness of the film. Such oil droplets have a solubility in water at room temperature of 0.01% by weight. Polymerization of the following hydrophobic high-boiling organic solvents (eg, liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, etc.) and polymer particles (eg, styrene, butyl acrylate, divinylbenzene, butyl methacrylate, hydroxyethyl methacrylate, etc.) Particles obtained by polymerizing one or more reactive monomers). Such oil droplets are preferably 10 to 50% by weight with respect to the hydrophilic binder.
Can be used.

In the present invention, a surfactant can be added to the ink receiving layer. 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 solution. 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 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. 3,3,5 triazine, a compound having a reactive halogen as described in U.S. Pat. No. 3,288,775; divinyl sulfone; a compound having a reactive olefin as described in U.S. Pat. No. 3,635,718; N-methylol compounds as described in Japanese Patent No. 2,732,316, U.S. Pat. No. 3,103,43
No. 7, isocyanates described in US Pat.
Aziridine compounds as described in US Pat. Nos. 7,280 and 2,983,611; carbodiimide-based compounds as described in US Pat. No. 3,100,704; US Pat.
1,537, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, and inorganic hardeners such as chrome alum, boric acid and borate. It can be used in combination of more than one kind.
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.

In the present invention, in addition to the surfactant and the hardener, the ink receiving layer further comprises a coloring dye, a coloring pigment, a fixing agent for the ink dye, an ultraviolet absorber, an antioxidant, a dispersant for the pigment, Antifoaming agent, leveling agent, preservative, optical brightener,
Various known additives such as a viscosity stabilizer and a pH adjuster can also be added.

In the present invention, the coating method is not particularly limited, and a known coating method can be used. For example,
There are a slide lip method, a curtain method, an extrusion method, an air knife method, a roll coating method, a ked bar coating method and the like.

In the present invention, one ink receiving layer is provided on the support, but an ink absorbing layer, an ink fixing layer, an intermediate layer, a protective layer and the like may be further provided.

Examples of the water-resistant support used in the present invention include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride, polyimide resins, cellophane, and the like. Examples include a resin film such as celluloid, a support in which paper is coated (laminated) with a polyolefin resin such as polyethylene or polypropylene, and a glass plate.

These supports may be transparent or opaque. The thickness of the water-resistant support used in the present invention is preferably about 50 to 200 μm.

A preferred support in the present invention is a paper coated with polyethylene terephthalate or polyolefin resin. Hereinafter, the polyolefin resin coating will be described in detail.

The base paper constituting the polyolefin resin-coated paper is not particularly limited, and generally used paper can be used, and more preferably, a smooth base paper used for a photographic support, for example, is preferable. 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. This base paper contains sizing agents, paper strength agents,
Additives such as fillers, antistatic agents, optical brighteners, dyes, etc. are compounded.

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. However, it is preferable that the base paper has good surface smoothness such as by compressing the paper by applying a pressure with a calender or the like during or after papermaking. ~250g / 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.
The polyolefin resin is a 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, the both surfaces 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 resin coating 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.

The ink jet recording sheet of the present invention has a surface electric resistance of the ink receiving layer of 20 ° C. and 65%.
The resistance is 1 × 10 ¹¹ Ω or less under the condition of RH, and the surface electric resistance of the back surface is 1 × 10 ¹¹ under the condition of 20 ° C. and 65% RH.
¹¹ Ω or less. Specifically, the ink jet recording sheet of the present invention is left for 2 hours or more under conditions of 20 ° C. and 65% RH to adjust the humidity, and then a commercially available surface electric resistance measuring instrument, for example, a high resistivity meter manufactured by Mitsubishi Chemical Corporation The measurement is performed using Heiresta IP or the like.

The surface electric resistance of the ink receiving layer of the ink jet recording sheet according to the present invention is 20 ° C., 65% RH.
Salt in the ink receiving layer as a way to below 1 × 10 ¹¹ Ω under the conditions of, potassium chloride, lithium chloride, or contain a water-soluble inorganic salts such as magnesium chloride, polymer with antistatic properties, for example, Sanyo Kasei Although a cationic polymer and an anionic polymer are commercially available from Kogyo Co., Ltd. under the name of Chemistat, a desired surface electric resistance can be obtained by including these polymers having antistatic performance. In the present invention, more preferably, the surface electric resistance value of the ink receiving layer is set to 1 × 10 ¹⁰ Ω or less.

The method for reducing the surface electric resistance of the back surface of the ink jet recording sheet to 1 × 10 ¹¹ Ω or less under the conditions of 20 ° C. and 65% RH in the present invention is as follows. Is preferably used. The backcoat layer may contain a water-soluble inorganic salt such as salt, potassium chloride, lithium chloride, and magnesium chloride as an antistatic agent, or a polymer having antistatic performance, such as a cationic polymer and an anionic polymer from Sanyo Chemical Industries, Ltd. Is commercially available under the name of Chemistat, but a desired surface resistance can be obtained by adding these polymers having antistatic properties. A binder or a pigment can be appropriately added to the back coat layer in addition to the antistatic agent. Further, as a method of lowering the surface electric resistance of the back surface, besides the method of providing the back coat layer, a method of directly kneading a polymer having antistatic performance into the resin forming the back surface in the case of resin-coated paper is also possible. is there. In the present invention, more preferably, the surface electric resistance of the back surface is set to 1 × 10 ¹⁰ Ω or less.

[0041]

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.

Example 1 As a support, LBKP (50 parts) and LBSP (50 parts) were used.
Part) of a pulp blend of 120 g / m ² , and a resin composition composed of low-density polyethylene (70 parts), high-density polyethylene (20 parts) and titanium oxide (10 parts) applied to the surface at 25 g / m ^2. And high-density polyethylene (5
0 parts) and a low-density polyethylene (50 parts) resin coating paper prepared by applying 25 g / m ² .

An ink receiving layer and a back coat layer having the following compositions were applied to the above support and dried to prepare a recording sheet. The coating amount of the fine silica in the ink receiving layer was 15 g / solid content.
It was m ^2. The ink receiving layer coating solution is prepared by dispersing fumed silica (10% by weight of the total) in a water: ethyl alcohol = 20: 1 dispersion medium with a high-pressure homogenizer, and then adding boric acid, polyvinyl alcohol and a surfactant. Thus, a coating solution (total solid content concentration of 10% by weight) was prepared. The coating solution was applied after being left for 2 hours. The solid coating amount of the back coat layer was 1 g / m ² in each case. In addition, a part means a solid content weight part.

<Recording sheet 1> Composition of ink receiving layer 100 parts of fumed silica (trade name: Aerosil 380, manufactured by Nippon Aerosil Co., Ltd., average primary particle size: 7 nm, specific surface area by BET method: 380 m ² / g) Boric acid (Special grade reagent) 3 parts Polyvinyl alcohol 20 parts (trade name: PVA235, manufactured by Kuraray Co., Ltd., degree of saponification 88%, average degree of polymerization 3500) Amphoteric surfactant 0.3 part (trade name: SWAM AM-2150) , Made by Nippon Surfactant) Sodium chloride (special grade reagent) 0.5 parts

Composition of back coat 99.5 parts of anionic polymer type antistatic agent (trade name: Chemistat 6120 manufactured by Sanyo Chemical Industries) 0.5 part of anionic surfactant (sodium di-2-ethylhexyl sulfosuccinate)

<Recording Sheet 2> A recording sheet 2 was prepared in the same manner except that the blending amount of sodium chloride in the recording sheet 1 was changed to 2 parts.

<Recording Sheet 3> A recording sheet 3 was prepared in the same manner except that the amount of sodium chloride in the recording sheet 1 was changed to 5 parts.

<Recording Sheet 4> A recording sheet 4 was prepared in the same manner as above except that sodium chloride was replaced by potassium chloride.

<Recording Sheet 5> A recording sheet 1 was prepared in the same manner except that the sodium chloride of the recording sheet 1 was replaced by 5 parts of an anionic polymer type antistatic agent (trade name: Chemistat 6120, manufactured by Sanyo Chemical Industries, Ltd.).

<Recording Sheet 6> A recording sheet 6 was prepared in the same manner except that the sodium chloride of the recording sheet 1 was replaced with 5 parts of a cationic polymer type antistatic agent (trade name: Chemistat 6300, manufactured by Sanyo Chemical Industries, Ltd.).

<Recording Sheet 7> A resin-coated paper used as the water-resistant support of the recording sheet 1 was prepared in the same manner except that a white polyethylene terephthalate film (manufactured by DuPont, 100 μm double-sided, easily adhered) was used.

<Recording Sheet 8> A resin-coated paper used as the water-resistant support of the recording sheet 1 was prepared in the same manner except that a transparent polyethylene terephthalate film (manufactured by DuPont, 100 μm double-sided, easily adhered) was used.

<Recording sheet 9> The fumed silica (trade name: Aerosil 380, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 7 nm, specific surface area 380 m ² / g by BET method) of the recording sheet 1 was converted to Aerosil 50. (Normal Aerosil Co., Ltd., average primary particle size 30 nm, specific surface area by BET method 50 m ² / g) The same procedure was carried out except for changing to 50 m ² / g.

<Recording Sheet 10> The fumed silica (trade name: Aerosil 380, manufactured by Nippon Aerosil Co., Ltd., average primary particle size 7 nm, specific surface area 380 m ² / g by BET method) of the recording sheet 1 was wet-processed. Silica (Tokuyama X-6
0, average particle diameter 6 μm).

<Recording Sheet 11> A recording sheet 11 was prepared in the same manner except that the amount of sodium chloride in the ink receiving layer of the recording sheet 1 was changed to 0.1 part.

<Recording Sheet 12> A recording sheet 12 was prepared in the same manner as above except that the sodium chloride in the ink image receiving layer was removed.

<Recording Sheet 13> A recording sheet 13 was prepared in the same manner except that the solid content of the anionic polymer type antistatic agent in the back coat layer of the recording sheet 2 was changed to 0.05 g / m ² .

<Recording Sheet 14> A recording sheet 14 was prepared in the same manner as above except that the back coat layer was removed.

The following evaluations were made on the ink jet recording sheets coated with the above 13 ink receiving layers. The ink jet recording was performed using a PM-770C color printer manufactured by Seiko Epson Corporation.
The printing and paper-passing properties were evaluated under the conditions of 65 ° C. and 65% RH. Table 1 shows the results.

<Measurement of Surface Electric Resistance> An unprinted ink jet recording sheet was subjected to the following tests at 20 ° C. and 65% RH.
After leaving it for 4 hours to adjust the humidity, the surface electrical resistance of the front and back surfaces of the ink jet recording sheet was measured using a high resistivity meter Hiresta IP manufactured by Mitsubishi Chemical Corporation.

<Paper-passing property> A set of 20 A4-size ink jet recording sheets was set on a paper tray of an ink jet printer, and a total of 5 sets (10 in total) were set.
(0 sheets) was continuously subjected to a printing test under the conditions of 20 ° C. and 30% RH, and the frequency of occurrence of paper feeding failure was counted.
The reason why the conditions were set at 20 ° C. and 30% RH is that the difference can be more clearly compared at low humidity.

<Glossiness> The glossiness of the surface of the unprinted ink jet recording sheet was visually determined. ：: High gloss and good. Δ: The gloss is slightly inferior to ○. ×: Low gloss.

<Printability> Solid printing of each color of red, blue, and green was performed, and printing defects such as ink overflow, mottling, and banding in the printing portion were evaluated according to the following criteria. ：: No defect at all. Δ: Some defects are observed. X: The defect is remarkable.

[0064]

[Table 1] ──────────────────────────────────── Sample Ink receiving layer Back side Glossiness Properties Printability Remarks Surface electric resistance Surface electric resistance 記録 Recording sheet 1 5.1 × 10 ¹⁰ 1.1 × 10 ⁸ 3 ○ ○ Recording sheet 2 of the present invention 2.3 × 10 ⁹ 1.1 × 10 ⁸ 1 ○ ○ Recording sheet 3 of the present invention 1.7 × 10 ⁸ 1.1 × 10 ⁸ ○ ○ Recording sheet 4 of the present invention 5.1 × 10 ⁸ 1.1 × 10 ⁸ 0 ○ ○ Recording sheet of the present invention 5 3.5 × 10 ⁹ 1.1 × 10 ⁸ ○ ○ Recording sheet of the present invention 6 2.5 × 10 ⁸ 1.1 × 10 ⁸ 0 ○ ○ Recording sheet of the present invention 7 2.3 × 10 ⁸ 1.3 × 10 ⁸ 0 ○ ○ Recording sheet of the present invention 8 2.3 × 10 ⁸ 1.3 × 10 ⁸ ○ ○ Recording sheet 9 of the present invention 3.1 × 10 ⁸ 1.1 × 10 ⁸⁰ × △ Comparative example Recording sheet 10 5.4 × 10 ⁸ 1.1 × 10 ⁸ 0 × × Comparative example recording sheet ^{11 5.2 × 10 11 1.1 × 10} 8 30 ○ Comparative Example recording sheet ^{12 3.3 × 10 12 1.1 × 10} 8 55 ○ ○ Comparative Example recording sheet ^{13 2.3 × 10 9 3.1 × 10} 11 41 ○ ○ Comparative Example recording sheet ^{14 2.3 × 10 9 5.1 × 10} 12 72 ○ ○ Comparative Example ────────────────────────────────────

As is evident from the above results, the ink jet recording sheet of the present invention not only has excellent printability and glossiness, but also can satisfy any of the performances without occurrence of a paper passing failure in an ink jet printer.

[0066]

According to the present invention, it is possible to provide an ink jet recording sheet which not only has excellent printability and glossiness but also does not cause a paper passing failure in an ink jet printer.

Claims (3)

[Claims] 1. An ink jet recording sheet having at least one ink receiving layer on a water-resistant support, wherein the ink receiving layer is formed of a porous layer containing inorganic fine particles having an average primary particle diameter of 20 nm or less. And the surface electric resistance of the ink receiving layer is 1 × 10 ¹¹ Ω or less under the conditions of 20 ° C. and 65% RH, and the surface electric resistance of the back surface of the water-resistant support is 20 ° C. and 65% RH. 1 × under the condition of
An ink jet recording sheet having a resistivity of 10 ¹¹ Ω or less. 2. The ink jet recording sheet according to claim 1, wherein the inorganic fine particles are fumed silica or alumina hydrate. 3. The ink jet recording sheet according to claim 1, wherein the water-resistant support is a resin-coated paper coated on both sides with a polyolefin resin or a transparent or opaque film made of polyethylene terephthalate resin.