JPH0768922A - Ink jet recording sheet - Google Patents

Abstract

PURPOSE:To enhance ink absorbability and the density or sharpness of an image by forming a support from a nonwoven fabric and forming an ink receiving layer from ultra-fine particulate inorg. pigment and a binder and specifying the Fragiel air permeability of a recording sheet. CONSTITUTION:An ink jet recording sheet is constituted by applying an ink receiving layer to a support. In this case, the support is formed from a nonwoven fabric. The ink receiving layer is formed mainly from ultra-fine particulate inorg. pigment with a primary particle size of 100nm or less and a binder. The Fragiel air permeability prescribed in JIS L1096 of the recording sheet is set to 100cm<3>/cm<2>.sec or less. The ultra-fine particulate inorg. pigment is composed of needle like or fibrous non-spherical cationic colloidal silica and the nonwoven fabric is composed of a wet nonwoven fabric. By this constitution, the ink jet recording sheet generating no exudation irregularity of ink, excellent in ink absorbability and forming an image enhanced in density or sharpness is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more specifically, it has excellent ink absorbency without uneven bleeding of ink, high density and sharpness of recorded image, and a perfect circle. The present invention relates to an ink jet recording sheet which gives a recording dot close to the above and has a unique texture.

The ink jet recording system is a system in which minute droplets of ink are ejected and adhered to a recording sheet such as paper by various operating principles to record images, characters, etc. It has features such as easy colorization, great flexibility in recording patterns, and no need for development-fixing, and is rapidly spreading in various applications as a recording device for various figures including Kanji and color images. Further, an image formed by a multicolor ink jet system can obtain a recording comparable to that of multicolor printing by a plate making system or printing by a color photographic system. Further, in applications requiring a small number of copies, it is being widely applied to the field of full-color image recording because it is cheaper than the photographic technique.

As a recording sheet used in this ink jet recording system, there is a high quality paper or a coated paper which is used for ordinary printing or writing, or those which are provided with an ink receiving layer to improve ink jet recording characteristics. .

On the other hand, in the fields of design, event, advertisement, etc., a color image recording which uses a durable and water-resistant support and is characterized by the texture of the support itself is becoming popular. In particular, for color image recording on a large screen such as a curtain used outdoors, the ink jet recording method is simple and widely used.

As an ink jet recording sheet, the density of print dots is high and the color tone is bright and vivid.
It is required that the ink does not flow out or bleed even when the print dots overlap due to the rapid ink absorption, the lateral spread of the print dots is not unnecessarily large, and the periphery is smooth and does not blur. It

However, the ink jet recording sheet using a conventional non-woven fabric as a support has not yet been satisfied with the above required characteristics.

[0007]

An object of the present invention is to provide an ink jet recording sheet having a non-woven fabric as a support, which is excellent in ink absorbency without unevenness of ink bleeding, and the density of a recorded image. It is an object of the present invention to obtain an ink jet recording sheet having high sharpness, recording dots close to a perfect circle and having a unique texture.

[0008]

Means for Solving the Problems As a result of intensive studies in view of the above, the present inventors have found that there is no ink bleeding, the ink absorbency is excellent, the density of a recorded image is high, and a recording dot close to a perfect circle is formed. The present invention has led to the invention of an ink jet recording sheet having a unique texture.

First, the ink jet recording sheet of the present invention is an ink jet recording sheet in which an ink receiving layer is coated on a support, the support is made of a non-woven fabric, and the ink receiving layer component is mainly 100 nm. It is characterized in that it is composed of an ultrafine particle inorganic pigment having the following primary particle diameter and a binder, and has a Frazier air permeability of 100 cm ³ / cm ² · sec or less defined by JIS L1096 of the recording sheet. .

Further, the ultrafine inorganic pigment is preferably non-spherical cationic colloidal silica.

Further, the non-spherical cationic colloidal silica is preferably acicular or fibrous.

In the ink jet recording sheet of the present invention, the non-woven fabric is a wet non-woven fabric.

Further, the Frazier air permeability of the support is 35.
It is characterized by being 0 cm ³ / cm ² · sec or less.

Secondly, in the ink jet recording sheet of the present invention, an ink receiving layer is coated on a support, and the support has a heating temperature of 100 to 250 ° C. and a linear pressure of 50 to 300 kg /. A non-woven fabric treated under a heat calendar condition of cm, in which the ink receiving layer component is mainly composed of ultrafine inorganic pigments having a primary particle diameter of 100 nm or less and a binder, and is defined by JIS L1096 of the recording sheet. The air permeability of fragile is 50 cm ³ / cm ² · sec or less.

The ultrafine inorganic pigment is preferably non-spherical cationic colloidal silica.

Further, the non-spherical cationic colloidal silica is preferably acicular or fibrous.

In the ink jet recording sheet of the present invention, the non-woven fabric is composed of organic synthetic fibers and heat adhesive fibers.

Further, the non-woven fabric is a wet non-woven fabric.

Further, the Frazier air permeability of the support is 10
It is characterized by being 0 cm ³ / cm ² · sec or less.

Hereinafter, the ink jet recording sheet of the present invention will be described in detail.

First, the ink jet recording sheet of the present invention has a Frazier air permeability of 100 cm ³ / cm ² · sec or less defined by JIS L1096, and thus has a texture unique to a non-woven fabric, and excellent recording. An image can be obtained.

An ink jet recording sheet having a non-woven fabric coated with an ink receiving layer on one surface has a non-woven fabric surface of 100 cm ³ / cm ² · sec or less as defined by the present invention. Since the ink receiving layer is formed as a substantially uniform coating layer, good recording characteristics can be maintained.
However, the Frazier air permeability of the recording sheet is 100 cm ³
When it exceeds / cm ² · sec, a large number of voids are formed on the surface of the coating layer of the ink-receptive layer, which is not preferable because the recorded image is uneven.

In the ink jet recording sheet of the present invention, when the ink receiving layer is provided on the surface of the non-woven fabric as the support, the non-woven fabric itself has a Frazier air permeability of 350 cm ³ / cm ^2.
・ It is preferable if it is not more than sec. This is not preferable because when the ink receiving layer is applied to the nonwoven fabric, if it exceeds 350 cm ³ / cm ² · sec, it becomes difficult to apply. However, even with a non-woven fabric having high Frazier air permeability, the recording sheet within the scope of the present invention can be obtained by applying an ink receiving layer using a pre-treated product. Even with a non-treated non-woven fabric, the recording sheet within the scope of the present invention can be obtained by controlling the coating amount of the ink receiving layer.

As the pretreatment of the non-woven fabric, for example, before coating the ink receiving layer, an undercoat layer is provided on the surface of the non-woven fabric with a pigment or the like, or the Frazier air permeability is lowered by a means such as a heat calender and the ink The coating of the receiving layer can be facilitated.

Secondly, the ink jet recording sheet of the present invention comprising an ink receiving layer coated on one side of a non-woven fabric treated under the thermal calendering conditions of a heating temperature of 100 to 250 ° C. and a linear pressure of 50 to 300 kg / cm. When the Frazier air permeability defined by JIS L1096 is 50 cm ³ / cm ² · sec or less, it has a texture unique to a nonwoven fabric and a good recorded image can be obtained.

The Frazier air permeability defined by the present invention is 5
Within the range of 0 cm ³ / cm ² · sec or less, since the ink receiving layer is formed as a substantially uniform coating layer on the surface of the nonwoven fabric, good recording characteristics can be maintained. However, when the Frazier air permeability of the recording sheet exceeds 50 cm ³ / cm ² · sec, voids are easily formed on the surface of the coating layer of the ink receiving layer,
This will affect the recorded image.

In the ink jet recording sheet of the present invention, when an ink receiving layer is provided on the surface of the non-woven fabric as a support, it is preferable that the thermal calendared non-woven fabric has a Frazier air permeability of 100 cm ³ / cm ² · sec or less. This is 100 cm when applying the ink receiving layer to the nonwoven fabric.
^If it exceeds ³ / cm ² · sec, the gap between the fibers of the formed nonwoven fabric becomes large, which is not preferable.

However, even with a non-woven fabric having a high Frazier air permeability, the recording sheet within the scope of the present invention can be obtained by applying a pre-treatment to the ink receiving layer. Even with a non-treated non-woven fabric, the recording sheet within the scope of the present invention can be obtained by controlling the coating amount of the ink receiving layer.

As the pretreatment of the non-woven fabric, for example, before the ink-receiving layer is coated, an undercoat layer is provided on the surface of the non-woven fabric with a pigment or the like to lower the Frazier air permeability, thereby facilitating the coating of the ink-receiving layer. can do.

The non-woven fabric as the support is made of organic synthetic fibers alone or in combination with heat-adhesive fibers. The non-woven fabric is subjected to a heat calendering treatment under the heating conditions. Temperature 100-250 ° C, linear pressure 50-30
It is 0 kg / cm.

The heating temperature and the linear pressure depend on the melting point (thermal softening point) of the organic synthetic fiber or the heat-adhesive fiber itself to be used, and at a temperature several degrees to 10 ° C. higher than the melting point of the fiber. I wish I had it. When the heat calendering treatment is performed at a heating temperature extremely higher than the melting point of the fiber, the heat calendering roll may be heat-fused, and the treatment conditions may be appropriately changed depending on the fiber used. .

The nonwoven fabric used in the present invention is roughly classified into
There are wet non-woven fabrics, dry non-woven fabrics such as stitch bond system, spun bond system, melt blow system, thermal bond system and jet bond system, or spun lace non-woven fabric using wet non-woven fabric or dry non-woven fabric.

Generally, the wetness of non-woven fabric is smaller than that of dry non-woven fabric, and the Frazier air permeability is preferable when it is used as a support of the ink jet recording sheet of the present invention.

The fibers of the non-woven fabric used in the present invention may be any fibers as long as they can form the non-woven fabric. For example, polyester-based fibers such as polyethylene terephthalate, polybutylene terephthalate, or homopolymers and copolymers of modified polymers of these polymers, and polyolefin-based fibers such as polypropylene, polyethylene, polystyrene, or homopolymers and copolymers of these modified polymers. Fibers, acrylic fibers, polyacrylonitrile fibers such as modacrylic fibers, nylon fibers such as nylon 6, nylon 66, polyvinyl alcohol fibers, urethane fibers, organic synthetic fibers such as acrylic fibers; and rayon, etc. Regenerated fibers such as regenerated cellulose fibers and fibers obtained by spinning a solution of collagen, alginic acid, chitin, etc .; semi-synthetic fibers such as acetate fibers;
Various fibers such as natural fibers such as cellulosic fibers such as hemp, cotton and pulp and protein fibers such as wool and silk; inorganic fibers such as metal fibers, glass fibers and carbon fibers; Can be used alone or in combination.

Further, these fibers may be used as a binder in combination with a polyolefin-based heat-adhesive fiber, a polyester-based heat-adhesive fiber or the like.

The fibers used in the above-mentioned non-woven fabric can be used by appropriately changing the fineness and the fiber length depending on the production method of the non-woven fabric, and are not limited.

In the first ink jet recording sheet of the present invention, the coating amount of the ink receiving layer can be appropriately changed according to the Frazier air permeability of the nonwoven fabric as the support. When the Frazier air permeability of the support is less than 150 cm ³ / cm ² · sec, the coating amount of the ink receiving layer is 1 to 1
It is about 0 g / m ² . Also, the Frazier air permeability of the support is 1
When it is in the range of 50 to 350 cm ³ / cm ² · sec, the coating amount of the ink receiving layer is about 10 to ²⁰ g / m ² .

In the second ink jet recording sheet of the present invention, the coating amount of the ink receiving layer can be appropriately changed according to the Frazier air permeability of the nonwoven fabric as the support. Frazier air permeability of the support is 50-100 cm ³ / cm ²
When the range is sec, the coating amount of the ink receiving layer is preferably about 5 to 15 g / m ² . Further, when the Frazier air permeability of the support is less than 50 cm ³ / cm ² · sec, the coating amount of the ink receiving layer is preferably about 1 to 10 g / m ² .

When an ink-receiving layer is provided using a support having a high Frazier air permeability, a support having an undercoat layer made of an inorganic or organic pigment on the surface of the support in advance,
Alternatively, it is an effective means that the coating amount of the ink receiving layer can be reduced by using a support which has been subjected to a thermal calendar treatment to reduce the voids on the surface of the support.

The ink jet recording sheet according to the present invention comprises a support surface coated with a specific ultrafine inorganic pigment and a binder, preferably an aspherical cationic colloidal silica and an ink receiving layer component mainly composed of the binder. Therefore, since the ultrafine particle inorganic pigment (the non-spherical cationic colloidal silica) has high ink absorbency, it is possible to represent a recording dot close to a perfect circle. The injected ink is an ultrafine inorganic pigment (non-spherical cationic colloidal silica) that absorbs ink instantly.
The excess ink is absorbed by and penetrates in the thickness direction of the support, which is the cross-sectional direction of the coating layer. Therefore, it is possible to obtain recorded dots without unevenness in ink bleeding.

The ink jet recording sheet of the present invention is mainly composed of a composition comprising an ultrafine particle inorganic pigment (non-spherical cationic colloidal silica) and a binder, and 100 parts by weight of the ultrafine particle inorganic pigment (the non-spherical cationic colloidal silica). Against the binder 5 to 3
An ink receiving layer is coated on a support using the ink receiving layer coating liquid prepared by mixing 0 parts by weight. Here, the amount of the binder is preferably 10 to 25 parts by weight.

If the amount of the binder in the coating liquid for the ink receiving layer is less than 5 parts by weight, the adhesiveness to the support will be poor, and if it exceeds 30 parts by weight, the binder will impair the ink absorbability. It is not preferable.

In the ink jet recording sheet of the present invention, the ink receiving layer coating liquid comprising the above composition is 4 to 25.
A coating liquid concentration of wt% is preferred. However, the coating liquid concentration may be appropriately changed depending on the method of coating on the support.

As a method of coating or impregnating the ink receiving layer on the support, various blade coaters, roll coaters,
Various devices such as an air knife coater, a bar coater, a rod coater, a gate roll coater, a curtain coater, a short dwell coater, a gravure coater, a flexogravure coater, and a size press can be used on-machine or off-machine. However, in the present invention, an air knife coater, a rod coater and a gate roll coater are particularly preferable.

The ultrafine particle inorganic pigment used in the present invention is
The primary particle size of the ultrafine inorganic pigment is 100 nm or less, preferably 50 nm or less. As these ultrafine particle inorganic pigments, those which are dispersed in water in a colloidal state while maintaining the primary particle size are used.

Examples of ultrafine particle inorganic pigments include the following. For example, silica (colloidal silica), alumina or alumina hydrate (alumina sol,
Colloidal alumina, cationic aluminum oxides or hydrates thereof, pseudo-boehmite, etc.), surface-treated cationic colloidal silica, aluminum silicate, magnesium silicate, magnesium carbonate and the like, more preferably primary particles are porous. However, it is preferable that even if it is non-porous, it aggregates at the time of preparing the coating solution or further aggregates at the time of drying the coating to form a porous coating layer surface on the surface of the support.

Among the ultrafine particle inorganic pigments, non-spherical cationic colloidal silica is preferable. As the non-spherical cationic colloidal silica, a metal oxide hydrate which is a cation modifier is used on the surface of the colloidal silica. It is coated with cation and modified with cation. The term “non-spherical” as used in the present invention means that it is not substantially spherical and has various forms such as needle-like, columnar, bead-like, rod-like, plate-like, lump-like, fibrous and spindle-like, but especially needle-like or A fibrous material is preferably used.

As the non-spherical cationic colloidal silica, colloidal silica coated with a cation modifier composed of a metal oxide hydrate such as aluminum oxide hydrate, zirconium oxide hydrate and tin oxide hydrate. Is preferably used, and in particular, cation-modified aluminum oxide hydrate is preferably used.

As a method of cation modification, US Pat.
It can be carried out by the method described in the specification of 3,007,878, Japanese Patent Publication No. 47-26959, etc.

The fiber diameter of the various fibers forming the support is several 1
With respect to the order of 0 μm, the maximum minor axis of the non-spherical cationic colloidal silica is 50 nm or less, preferably 30.
nm or less, the length of the colloidal silica is 300
nm or less, preferably 100 nm or less.

As the non-spherical cationic colloidal silica, those which are dispersed in water in a colloidal state while maintaining the primary particle size are usually used.

In the non-spherical cationic colloidal silica, the coating amount of the metal oxide hydrate as the cation modifier is useful in the range of 1 to 30% by weight in terms of metal oxide with respect to silica (in terms of SiO ₂ ). Is. If the coating amount of the cation modifier is too small (1% by weight), the water resistance of the image recorded on the ink jet recording sheet will be significantly deteriorated. On the contrary, if it is too large, the physical properties of the coating on the coated surface will be weakened. It causes cracks, which is not preferable. The coating amount is preferably 2.5 to 25% by weight, more preferably 5 to 20% by weight.

The non-spherical cationic colloidal silica dispersion may contain an acid component such as acetic acid, citric acid, sulfuric acid or phosphoric acid for the purpose of a colloid stabilizer.

Further, as the ultrafine particle inorganic pigment or the inorganic pigment which can be used in combination with the non-spherical cationic colloidal silica, any conventionally known inorganic pigment can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate,
Examples thereof include synthetic amorphous silica, aluminum hydroxide, lithopone, zeolite, hydrohaloysite, magnesium hydroxide and the like.

Among these inorganic pigments, porous inorganic pigments are preferable, and examples thereof include porous synthetic amorphous silica, porous magnesium carbonate, porous alumina and the like, and particularly porous synthetic amorphous having a large pore volume. Silica is preferred.

Further, styrene plastic pigment,
Organic pigments such as acrylic plastic pigments, polyethylene, microcapsules, urea resins and melamine resins can be used together with the above ultrafine inorganic pigments (non-spherical cationic colloidal silica).

As the binder used together with the ultrafine inorganic pigment (non-spherical cationic colloidal silica), for example, polyvinyl alcohol, vinyl acetate, oxidized starch,
Etherified starch, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, soybean protein, silyl modified polyvinyl alcohol, etc .; maleic anhydride resins, styrene-butadiene copolymers, methyl methacrylate-butadiene copolymers and other conjugated dienes. -Based copolymer latex; acrylic-based polymer latex such as acrylic acid ester and methacrylic acid ester polymer or copolymer, acrylic acid and methacrylic acid polymer or copolymer; vinyl such as ethylene-vinyl acetate copolymer -Based polymer latex; or functional group-modified polymer latex with a functional group-containing monomer such as carboxyl group of these various polymers; water-based binder of thermosetting synthetic resin such as melamine resin and urea resin; polymethylmethacrylate , Poly Urethane resin, unsaturated polyester resin, vinyl chloride - vinyl acetate copolymer, polyvinyl butyral, can be mentioned synthetic resin binder such as alkyd resins, it may be used in at least 1 or more.

Further, a cationic resin added for the purpose of fixing a conventionally known dye can be used together.

Further, as other additives, pigment dispersants, thickeners, fluidity improvers, defoamers, foam suppressors, release agents,
Foaming agents, penetrants, coloring dyes, coloring pigments, optical brighteners, ultraviolet absorbers, antioxidants, preservatives, antifungal agents, waterproofing agents, wet paper strengthening agents, dry paper strengthening agents, etc. It can also be blended.

The ink jet recording ink referred to in the present invention is a water-based ink comprising the following colorant, liquid medium and other additives.

Examples of colorants include water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes and food dyes.

As the solvent for the aqueous ink, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, C1-C4 alkyl alcohols such as isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol, polypropylene glycol Polyalkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol,
Alkylene glycols having 2 to 6 alkylene groups such as thiodiglycol, hexylene glycol and diethylene glycol; polyhydric alcohols such as glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol and monomethyl ether Lower alkyl ethers and the like can be mentioned. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether are preferable.

Other additives include, for example, a pH adjusting agent, a sequestering agent, an antifungal agent, a viscosity adjusting agent, a surface tension adjusting agent, a wetting agent, a surfactant, and a rust preventive agent.

The ink jet recording sheet according to the present invention is not limited to use as an ink jet recording sheet, but may be used as any recording sheet using a liquid ink during recording. For example, for thermal transfer recording in which an ink sheet coated with a heat-melting ink containing a heat-melting substance, a dye or pigment as a main component on a non-woven fabric as a support is heated from the back side to melt and transfer the ink. Image-receiving sheet, heat-meltable ink is heated and melted to form fine droplets,
Corresponding to inkjet recording sheet for flight recording, inkjet recording sheet using ink in which oil-soluble dye is dissolved in solvent, photosensitive pressure-sensitive donor sheet using microcapsule containing photopolymerizable monomer and colorless or colored dye / pigment An image receiving sheet and the like can be mentioned.

The common point of these recording sheets is that the ink is in a liquid state at the time of recording. The liquid ink penetrates or spreads in the depth direction or the horizontal direction of the ink receiving layer of the recording sheet before being cured, solidified, or fixed. The various recording sheets described above require absorptivity according to their respective methods, and the inkjet recording sheet of the present invention may be used as the various recording sheets described above without any limitation.

Further, the ink jet recording sheet of the present invention can be used as a recording sheet for heating and fixing the toner of the electrophotographic recording system which is widely used in copying machines and printers.

[0067]

The first ink jet recording sheet of the present invention is
An inkjet recording sheet having an ink-receiving layer coated on a support, wherein the ink-receiving layer component is mainly composed of specific ultrafine particle inorganic pigment and binder, preferably non-spherical cationic colloidal silica and binder,
When the Frazier air permeability of the recording sheet specified by JIS L1096 is 100 cm ³ / cm ² · sec or less, an inkjet recording sheet having excellent recording characteristics and a unique texture can be obtained.

This is due to the use of a specific ultrafine particle inorganic pigment, preferably a specific cationic colloidal silica, as a component of the ink receiving layer, and when the ink is applied to the ink receiving layer surface of the recording sheet, By not penetrating in the surface direction but penetrating into the ink receiving layer surface and surplus ink penetrating in the thickness direction of the support, it is possible to obtain a recording dot shape close to a perfect circle. Further, it is possible to obtain an ink jet recording sheet having a recorded image with high density and sharpness.

The second ink jet recording sheet of the present invention is an ink jet recording sheet in which an ink receiving layer is coated on a support, and the support has a heating temperature of 100 to 250.
A non-woven fabric which has been treated under the condition of a temperature of 50 ° C. and a linear pressure of 50 to 300 kg / cm, and the ink receiving layer component is mainly composed of a specific ultrafine particle inorganic pigment and a binder, preferably a non-spherical cationic colloidal silica and a binder. In addition, when the recording sheet has a Frazier air permeability of 50 cm ³ / cm ² · sec or less defined by JIS L1096, an inkjet recording sheet having excellent recording characteristics and a unique texture can be obtained.

This is due to the use of a specific ultrafine particle inorganic pigment, preferably a specific cationic colloidal silica, as the ink receiving layer component, and when the ink is applied to the ink receiving layer surface of the recording sheet, By not penetrating in the surface direction but penetrating into the ink receiving layer surface and surplus ink penetrating in the thickness direction of the support, it is possible to obtain a recording dot shape close to a perfect circle. Further, it is possible to obtain an ink jet recording sheet having a recorded image with high density and sharpness.

[0071]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.
Further, “parts” and “%” shown in the examples represent parts by weight and% by weight, unless otherwise specified.

The required characteristics of the ink jet recording sheets prepared in the following Examples and Comparative Examples were evaluated. The evaluation methods shown below were evaluated, and the evaluation results are shown in Tables 1 to 1 below. They are listed in 4.

[Ink Absorption and Sharpness] The ink absorption and the sharpness of the image are determined by the boundary of the solid color solid print portion, for example,
The degree of ink bleeding at the boundary between the red print (magenta + yellow) and the green print (cyan + yellow) was visually determined. When the red printed portion and the green printed portion did not overlap and were separated, the characteristics were good, and when the overlapping was large and a black line was formed, the characteristics were bad. A substance having poor ink absorbability remarkably impairs image quality (image sharpness), so that it does not make any sense even if other properties such as image density are good. In addition, as an evaluation criterion, A indicates a good characteristic, B indicates a good practically acceptable range, C indicates a practical problem, and D indicates a poor characteristic.

[Image Density] The image density is a reflection densitometer (Macbeth RD91
8: manufactured by Macbeth). The higher the value, the higher the image density and the better, but normally, 1.20 or more is good.

[Dot shape factor] An ink jet printer (IO-720: manufactured by Sharp Corporation) is used to print a single color dot of black ink, and an image analyzer analyzes the dot perimeter L and the dot area A. Was measured, and the dot shape factor C defined by the following equation 1 was calculated. The larger the dot shape coefficient C is from 1.0, the more irregular the dot shape due to dot bleeding.

[0076]

## EQU1 ## C = L ² / (4π × A) where C is the dot shape factor, L is the perimeter of the dot, and A
Represents the area of a dot.

Example 1 [Preparation of Nonwoven Fabric] NBKP4 with Freeness of 480 mlcsf
0 parts, polyester fiber (fiber diameter 2 denier, fiber length 5
mm) 60 parts of an aqueous slurry was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by using a wet papermaking method. The non-woven fabric thus produced had a Frazier air permeability of 100 cm ³ / cm ² · sec.

[Coating of ink receiving layer] As a composition of the ink receiving layer, colloidal silica (Snowtex-Y) is used.
L, Nissan Chemical, primary particle size 50-80 nm) 100
And polyvinyl alcohol (PVA11
7, Kuraray Co., Ltd., 30 parts, as a dye fixing agent, a cationic resin (Polyfix 601, cationic charge amount 6.9 me)
q./g, manufactured by Showa High Polymer Co., Ltd.) An aqueous dispersion containing 30 parts as a main component and having a solid content concentration of 10% is applied by an air knife coater so as to have a dry solid content of 10.0 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The Frazier air permeability of the produced inkjet recording sheet was 20 cm ³ / cm ² · sec.

Example 2 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the ink-receiving layer composition of Example 1 was applied so that the dry solid content was 5.0 g / m ^2. did. The inkjet recording sheet produced had a Frazier air permeability of 45.
It was cm ³ / cm ² · sec.

Example 3 In the same manner as in Example 1 except that the ink receiving layer composition of Example 1 was used to apply a dry solid content of 2.0 g / m ² using a size press. An inkjet recording sheet was prepared. The Frazier air permeability of the manufactured inkjet recording sheet was 90 cm ³ / cm ² · sec.

Comparative Example 1 Instead of the colloidal silica used in Example 1, another colloidal silica having a large primary particle diameter (Snowtex P) was used.
ST-3, Nissan Chemical, primary particle size 300 ± 30 nm)
An inkjet recording sheet was produced in the same manner as in Example 3 except that 100 parts of was used. The inkjet recording sheet produced had a Frazier air permeability of 90 cm ³ / cm ² · sec.
Met.

Comparative Example 2 The air permeability of the Frazier prepared in Example 1 was 100 cm ³ / cm ^2.
The non-woven fabric of sec was used as an inkjet recording sheet.

Example 4 [Preparation of Nonwoven Fabric] An aqueous slurry consisting of 95 parts of glass fibers having a fiber diameter of 1 μm and 5 parts of hot water-soluble polyvinyl alcohol fibers (2 denier, fiber length 3 mm) was prepared and subjected to a wet papermaking method. A non-woven fabric having a basis weight of 60 g / m ² was produced. The non-woven fabric thus produced had a Frazier air permeability of 350 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] As the ink receiving layer composition, cationic colloidal silica (Snowtex-AK (3), manufactured by Nissan Kagaku Co., Ltd., primary particle diameter 10 to 20) is applied.
nm) 100 parts, polyvinyl alcohol (PVA 117, manufactured by Kuraray Co., Ltd.) as an adhesive agent, 30 parts, cationic resin (Sumiraz resin 1001, cationic charge amount 3.5 meq./g, manufactured by Sumitomo Chemical Co., Ltd.) as a dye fixing agent 30 parts. An aqueous dispersion containing 20% of solid content as a main component is coated with an air knife coater to a dry solid content of 20.0 g / m ² , dried, and machine calendered to form an inkjet recording sheet. It was made. The produced inkjet recording sheet had a Frazier air permeability of 100 cm ³ / cm ² · sec.

Comparative Example 3 InkJet in the same manner as in Example 4 except that the nonwoven fabric prepared in Example 4 was used to apply the ink-receiving layer composition so that the dry solid content would be 15.0 g / m ^2. A recording sheet was prepared. The Frazier air permeability of the inkjet recording sheet at this time was 150 cm ³ / cm ² · sec.

Example 5 [Preparation of Nonwoven Fabric] A 40% aqueous dispersion of 80 parts of calcined kaolin and 20 parts of styrene-butadiene latex was added to the nonwoven fabric prepared in Example 4 so that the dry solid content was 15 g / m ^2. Was coated with an air knife coater, dried, and calendered to prepare an undercoated nonwoven fabric. The produced Frazier air permeability was 140 cm ³ / cm ² · sec.

[Coating of ink receiving layer] The ink receiving layer composition of Example 4 was made into an aqueous dispersion having a solid content concentration of 10%, and the dry solid content was adjusted to 4.0 g / m ² by using an air knife coater. An inkjet recording sheet was produced in the same manner as in Example 4 except that the coating was performed as described above. The inkjet recording sheet produced had a Frazier air permeability of 100 cm ³ / cm ² · sec.
Met.

Comparative Example 4 Same as Example 5 except that the ink-receiving layer composition was coated using the undercoated non-woven fabric prepared in Example 5 so that the dry solid content was 3.0 g / m ^2. Then, an inkjet recording sheet was prepared. The Frazier air permeability of the inkjet recording sheet at this time was 125 cm ³ / cm ² · sec.

Example 6 [Production of Nonwoven Fabric] 60 parts of polyester fiber (fiber diameter 1.4 denier, fiber length 51 mm), polypropylene fiber (fiber diameter 2 to 3 denier, fiber length 38 to 51 mm) 20
Part and 10 parts of polyester-based heat-bonded composite fiber (fiber diameter 2 denier, fiber length 51 mm) were uniformly mixed to prepare a nonwoven fabric having a basis weight of 60 g / m ² by the card method. The non-woven fabric thus produced had a Frazier air permeability of 120 cm ³ / cm ² · sec. Further, the produced non-woven fabric was calendered using a thermal calender to obtain a support of Example 7. The Frazier air permeability at this time was 30 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] As an ink receiving layer composition, 100 parts of alumina hydrate (Cataloid AS-3, manufactured by Catalysts & Chemicals Industries Co., Ltd., primary particle diameter: about 10 nm), polyvinyl alcohol (PVA117 as an adhesive) were used. , Kuraray Co., Ltd.), and 30 parts of a cationic resin (Polyfix 601, cation charge amount of 6.9 meq./g, Showa High Polymer Co., Ltd.) as a dye fixing agent, and an aqueous solution having a solid content concentration of 10%. The dispersion was applied using an air knife coater to a dry solid content of 3.5 g / m ² , dried, and machine calendered to prepare an inkjet recording sheet. The Frazier air permeability of the produced inkjet recording sheet was 20 cm ³ / cm ² · sec.

Comparative Example 5 Using the non-thermal calendered nonwoven fabric prepared in Example 6, the ink receiving layer composition was dried in the same manner as in Example 6 so that the dry solid content was 3.5 g / m ^2. To prepare an ink jet recording sheet. The inkjet recording sheet thus produced had a Frazier air permeability of 115 cm ³ / cm ² · sec.

Comparative Example 6 In place of the alumina hydrate used in Example 6, 333 parts of a 30% aqueous dispersion of powder silica (Nipsil E220A, manufactured by Nippon Silica Industry Co., Ltd., average particle size 1.0 μm) was used. An inkjet recording sheet was produced in the same manner as in Example 6 except for the above. The Frazier air permeability of the produced inkjet recording sheet was 25 cm ³ / cm ² · sec.

The ink jet recording sheets prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were evaluated based on the above-mentioned evaluation method, and the results are shown in Table 1.

[0094]

[Table 1]

From the results shown in Table 1, the ink jet recording sheet of the present invention uses the ultrafine particle inorganic pigment having a particle size of 100 nm or less, and the Frazier air permeability of the recording sheet is within the range of the invention. Sex, image density,
The sharpness was good, the dot shape factor was small, and the recorded dot shape was close to a perfect circle.

In Example 3 and Comparative Example 1, colloidal silica having different particle diameters was used and the coating amount was the same, but
Comparative Example 1 was inferior in sharpness and had a large dot shape factor.

In Comparative Example 2, the nonwoven fabric itself was used as an ink jet recording sheet, but all the evaluation results were inferior.

[0098] In Example 4 and Comparative Example 3, but Frazier air permeability as a support is a case of using a 350cm ³ / cm ² · sec and high nonwoven, respectively ^{20g / m 2, 15g / m} 2 and multimers The coating amount was applied to control the Frazier air permeability of the recording sheet. Frazier air permeability of 100 cm ³ / cm ² · sec
If it is less than the above, it is good, but if it exceeds this, the ink absorbency, the sharpness, and the dot shape coefficient are poor.

Example 5 and Comparative Example 4 are examples in which the nonwoven fabric of Example 4 was subjected to the undercoating treatment with the pigment, but in Comparative Example 4 in which the coating amount was low, the Frazier air permeability of the recording sheet was low. Since it was low, the image density, sharpness and dot shape factor were poor.

In Example 6 and Comparative Example 5, the same coating amount was used.
This is a difference example of the presence or absence of the thermal calendar treatment of the non-woven fabric, but when the non-treated non-woven fabric was used, all the evaluation results were inferior because the Frazier air permeability was high.

In Example 6 and Comparative Example 6, the components of the ink receiving layer were changed, but when silica having a large particle size was used, the image density, sharpness and dot shape coefficient were poor.

Example 7 [Production of Nonwoven Fabric] NBKP4 with Freeness of 480 mlcsf
0 parts, polyester fiber (fiber diameter 2 denier, fiber length 5
mm) 60 parts of an aqueous slurry was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by using a wet papermaking method. The non-woven fabric thus produced had a Frazier air permeability of 100 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] As a composition of the ink receiving layer, acicular needle-like colloidal silica is added to silica (SiO 2).
₂ equivalent) to Al ₂ O ₃ modified with aluminum oxide hydrate about 6.2 wt% in terms of acicular 10% aqueous dispersion of cation-modified colloidal silica (particle size: width 10 to 20
nm × length 50 to 200 nm) 1000 parts, 10% aqueous solution of polyvinyl alcohol as an adhesive (PVA11
7, Kuraray Co., Ltd.) 50 parts, and a 60% aqueous solution of a cationic resin as a dye fixing agent (Polyfix 601, cation charge 6.9 meq./g, Showa Polymer Co., Ltd.) 16.7 parts An aqueous dispersion having a solid content of 10% is applied onto the non-woven fabric prepared above using an air knife coater so as to have a dry solid content of 10.0 g / m ² , dried, and machine calendered to form an inkjet. A recording sheet was prepared. The Frazier air permeability of the produced inkjet recording sheet was 15 cm ³ / cm ² · sec.

Example 8 An ink jet recording sheet was prepared in the same manner as in Example 7 except that the ink receiving layer composition of Example 7 was applied to give a dry solid content of 5.0 g / m ^2. did. The inkjet recording sheet produced had a Frazier air permeability of 85.
It was cm ³ / cm ² · sec.

Example 9 In the same manner as in Example 7 except that the ink-receiving layer composition of Example 7 was used and coated using a size press so that the dry solid content was 2.0 g / m ^2. An inkjet recording sheet was prepared. The Frazier air permeability of the produced inkjet recording sheet was 85 cm ³ / cm ² · sec.

Example 10 Instead of the needle-shaped cationic colloidal silica used in Example 7, a 10% aqueous dispersion of needle-shaped colloidal silica (particle size; width 10-20 nm × length 50-200 coagulation) was used. An inkjet recording sheet was produced in the same manner as in Example 8 except that 1000 parts of the assembly) was used and the dry solid content was set to 8.0 g / m ² as the ink receiving layer. The inkjet recording sheet produced had a Frazier air permeability of 80.
It was cm ³ / cm ² · sec.

Example 11 [Preparation of Nonwoven Fabric] An aqueous slurry consisting of 95 parts of glass fiber having a fiber diameter of 1 μm and 5 parts of hot water-soluble polyvinyl alcohol fiber (2 denier, fiber length 3 mm) was prepared and subjected to a wet papermaking method. A non-woven fabric having a basis weight of 60 g / m ² was produced. The non-woven fabric thus produced had a Frazier air permeability of 350 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] Same as Example 7 except that the composition of the ink receiving layer of Example 7 was coated so that the amount of dry solid matter was 20.0 g / m ^2. Then, an inkjet recording sheet was prepared. The inkjet recording sheet produced had a Frazier air permeability of 100 cm ³ / cm ² · s.
It was ec.

Comparative Example 7 InkJet in the same manner as in Example 11 except that the nonwoven fabric prepared in Example 11 was used to apply the ink-receiving layer composition so that the dry solid content would be 15.0 g / m ^2. A recording sheet was prepared. The Frazier air permeability of the inkjet recording sheet at this time was 180 cm ³ / cm ² · sec.

Example 12 [Preparation of Nonwoven Fabric] A 40% aqueous dispersion of 80 parts of calcined kaolin and 20 parts of styrene-butadiene latex was added to the nonwoven fabric prepared in Example 11 so that the dry solid content was 15 g / m ^2. Was coated with an air knife coater, dried, and calendered to prepare an undercoated nonwoven fabric. The produced Frazier air permeability was 140 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] In the same manner as in Example 7 except that the composition of the ink receiving layer of Example 7 was coated so that the dry solid content was 4.0 g / m ^2. An inkjet recording sheet was prepared. The Frazier air permeability of the produced inkjet recording sheet was 95 cm ³ / cm ² · sec.

Comparative Example 8 Same as Example 7 except that the ink-receiving layer composition was coated using the undercoated non-woven fabric prepared in Example 12 so that the dry solid content was 3.0 g / m ^2. Then, an inkjet recording sheet was prepared. The Frazier air permeability of the inkjet recording sheet at this time was 120 cm ³ / cm ² · sec.

Example 13 Instead of the coating liquid for the ink-receiving layer of Example 7, a 10% aqueous dispersion of columnar cationic colloidal silica (particle size; width 40) was used.
nm x length 100 to 300 nm) 1000 parts, 10% aqueous solution of polyvinyl alcohol as an adhesive (PVA11
7, Kuraray Co., Ltd.) and 60% aqueous solution of a cationic resin as a dye fixing agent (Polyfix 601, cation charge amount 6.9 meq./g, Showa Polymer Co., Ltd.) 16.7 parts An aqueous dispersion having a solid content of 15% was coated on the undercoated non-woven fabric prepared in Example 12 using an air knife coater so that the dry solid content was 8 g / m ² , dried, and machine calendered. An ink jet recording sheet was prepared by finishing. The Frazier air permeability of the produced inkjet recording sheet was 25 cm ³ / cm ² · sec.

Example 14 Instead of the columnar cationic colloidal silica used in Example 13, 30 globular cationic colloidal silica was used.
An ink jet recording sheet was produced in the same manner as in Example 13 except that 333 parts by weight of the aqueous dispersion (primary particle diameter 80 nm) was used. The Frazier air permeability of the produced inkjet recording sheet was 28 cm ³ / cm ² · sec.

Comparative Example 9 Instead of the columnar cationic colloidal silica used in Example 13, a 30% aqueous dispersion of powder silica (Nipsil E220A, manufactured by Nippon Silica Industry Co., Ltd., average particle size 1.0 μm) was used.
An inkjet recording sheet was produced in the same manner as in Example 13 except that 333 parts of m) was used. The inkjet recording sheet produced had a Frazier air permeability of 35 cm ³ / c.
It was m ² · sec.

Comparative Example 10 Frazier air permeability of 350 cm ³ / cm ² prepared in Example 11
The non-woven fabric of sec was used as an inkjet recording sheet.

Example 15 [Preparation of Nonwoven Fabric] 60 parts of polyester fiber (fiber diameter 1.4 denier, fiber length 51 mm), polypropylene fiber (fiber diameter 2 to 3 denier, fiber length 38 to 51 mm) 20
Part and 10 parts of polyester-based heat-bonded composite fiber (fiber diameter 2 denier, fiber length 51 mm) were uniformly mixed to prepare a nonwoven fabric having a basis weight of 60 g / m ² by the card method. The non-woven fabric thus produced had a Frazier air permeability of 120 cm ³ / cm ² · sec. Further, the produced non-woven fabric was calendered using a thermal calender to obtain a support of Example 15. The Frazier air permeability at this time was 30 cm ³ / cm ² · sec.

[Coating of Ink Receiving Layer] In the same manner as in Example 9 except that the composition of the ink receiving layer of Example 9 was coated so that the dry solid content was 2.5 g / m ^2. An inkjet recording sheet was prepared. The Frazier air permeability of the produced inkjet recording sheet was 15 cm ³ / cm ² · sec.

Comparative Example 11 The non-woven fabric prepared in Example 15 before thermal calendering was used to prepare an ink-receiving layer composition in the same manner as in Example 15 so that the dry solid content was 2.5 g / m ^2. To prepare an ink jet recording sheet. The inkjet recording sheet produced had a Frazier air permeability of 115 cm ³ / cm ² · sec.
Met.

The above Examples 7 to 15 and Comparative Examples 7 to 11
The inkjet recording sheet prepared in 1 above was evaluated based on the above-described evaluation method, and the results are shown in Table 2.

[0121]

[Table 2]

From the results shown in Table 2, the ink jet recording sheet of the present invention uses an ultrafine particle inorganic pigment, particularly a non-spherical cationic colloidal silica, and the Frazier air permeability of the recording sheet falls within the range of the invention. Therefore, the ink absorptivity, the image density, and the sharpness were good, and the dot shape coefficient was small and the recording dot shape was close to a perfect circle.

[0123] In Example 11 and Comparative Example 7, but Frazier air permeability as a support is a case of using a 350cm ³ / cm ² · sec and high nonwoven, respectively ^{20g / m 2, 15g / m} 2
And a large coating amount was applied to control the Frazier air permeability of the recording sheet. Frazier air permeability of 100 cm ³ / cm ² · s
If it is ec or less, it is good, but if it exceeds this, both the sharpness and the dot shape coefficient are poor.

Example 12 and Comparative Example 8 are examples in which the nonwoven fabric of Example 11 was used with the undercoating treatment with a pigment. In Comparative Example 8 having a low coating amount, the Frazier air permeability of the recording sheet was low. Since it was low, the image density, sharpness and dot shape factor were poor.

Examples 13 to 14 and Comparative Example 9 are examples in which the ink-receiving layer components were changed with the same coating amount, but in Comparative Example 9, the image density was low and the dot shape factor and sharpness were also high. inferior.

In Comparative Example 10, the nonwoven fabric of Example 11 was used as it was as an ink jet recording sheet, but all the properties were poor. In particular, the dot shape factor could not be measured.

In Example 15 and Comparative Example 11, a dry non-woven fabric was used. In Example 15, a non-woven fabric obtained by thermal calendering was used. In Comparative Example 11, an untreated non-woven fabric was used to apply the same coating amount. It was set up. In Example 15, all evaluations were good, but in Comparative Example 11, it was poor because of high Frazier air permeability.

Example 16 [Preparation of support] 60 parts of polyester fiber (fiber diameter: 0.5 denier, fiber length: 5 mm), NB having a freeness of 480 ml
An aqueous slurry composed of 40 parts of KP was prepared and a nonwoven fabric having a basis weight of 50 g / m ² was prepared by using a wet papermaking method. The Frazier air permeability of the produced non-woven fabric was 45 cm ³ / cm ² · sec. Subsequently, this non-woven fabric is heated at a heating temperature of 250 ° C. and a linear pressure of 30.
A heat calendar treatment was performed under the condition of 0 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 13 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] As an ink receiving layer composition, alumina hydrate (Cataloid A) was used.
S-3, manufactured by Catalysts & Chemicals Industry Co., Ltd., primary particle diameter of about 10 nm) 1
00 parts, polyvinyl alcohol (PVA1 as an adhesive
17, Kuraray Co., Ltd., 30 parts, cationic resin (Polyfix 601, cationic charge amount 6.9) as a dye fixing agent.
Meq./g, manufactured by Showa Highpolymer Co., Ltd.) An aqueous dispersion containing 30 parts as the main component and having a solid content concentration of 10% is applied to a dry solid content of 2.0 g / m ² using a roll coater and dried. Then, it was machine calendered to prepare an inkjet recording sheet. The Frazier air permeability of the manufactured inkjet recording sheet was 8 cm ³ / cm ² · sec.

Comparative Example 12 [Preparation of Support] The nonwoven fabric prepared in Example 16 was used for thermal calendering under the conditions of a heating temperature of 260 ° C. and a linear pressure of 320 kg / cm. Since both were too high in the range of the present invention, they adhered to the hot roll during the thermal calendering process and could not be properly treated as a support. Therefore, the ink receiving layer could not be coated, and the inkjet recording sheet was not produced.

Comparative Example 13 [Preparation of Support] 75 parts of polyester fiber (fiber diameter: 2 denier, fiber length: 5 mm), NBK having a freeness of 480 ml
An aqueous slurry containing 25 parts of P was prepared and a non-woven fabric having a basis weight of 50 g / m ² was prepared using a wet papermaking method. The Frazier air permeability of the produced nonwoven fabric was 175 cm ³ / cm ² · sec. This non-woven fabric was not subjected to thermal calender treatment and was used as it was as a support for an inkjet recording sheet.

[Preparation of Inkjet Recording Sheet] The non-thermocalendered nonwoven fabric was coated with the coating liquid for the ink-receiving layer used in Example 16 in a dry solid content of 2.0 g / m ² as in Example 16. Was coated, dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet thus produced had a Frazier air permeability of 170 cm ³ / cm ² · sec.

Example 17 [Preparation of support] 90 parts of polyester fiber (fiber diameter 0.5 denier, fiber length 5 mm), polypropylene-ethylene vinyl acetate composite fiber (fiber diameter 2
An aqueous slurry consisting of 10 parts of denier, fiber length 5 mm, melting point 97 ° C.) was prepared, and the basis weight was 50 g /
A m ² non-woven fabric was prepared. The non-woven fabric thus produced had a Frazier air permeability of 65 cm ³ / cm ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 100 ° C. and a linear pressure of 50 kg / cm to obtain a support for an inkjet recording sheet. Frazier air permeability of the support is 30 cm ³ / cm ²
・ It was sec.

[Preparation of Inkjet Recording Sheet] As the composition of the ink receiving layer, colloidal silica (Snowtex-YL, manufactured by Nissan Kagaku Co., Ltd., primary particle size: 50 to 80 n)
m) 100 parts, polyvinyl alcohol (P
VA117, manufactured by Kuraray Co., Ltd., 30 parts, and 30 parts of a cationic resin (Polyfix 601, cation charge amount of 6.9 meq./g, Showa Polymer Co., Ltd.) as a dye fixing agent, with a solid content of 10%. The aqueous dispersion was coated on the above support using a size press so that the dry solid content was 1.5 g / m ² , dried, and machine-calendered to produce an inkjet recording sheet. The Frazier air permeability of the produced inkjet recording sheet was 26 cm ³ / cm ² · sec.

Comparative Example 14 [Production of Support] The nonwoven fabric produced in Example 17 was subjected to thermal calendaring under the conditions of a heating temperature of 90 ° C. and a linear pressure of 40 kg / cm to obtain a support for an ink jet recording sheet. The Frazier air permeability of the support was 60 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 17 in the same manner as in Example 17 so that the dry solid content was 1.5 g / m ^2. An ink jet recording sheet was prepared by working, drying and machine calendering. The inkjet recording sheet produced had a Frazier air permeability of 55 cm ³ / cm ² · sec.
Met.

Example 18 [Preparation of support] 80 parts of polyester fibers (fiber diameter: 1.4 denier, fiber length: 51 mm), polypropylene fibers (fiber diameter: 3 denier, fiber length: 38 to 5) as heat-bonding fibers
20 parts of 1 mm and a melting point of 153 ° C.) were uniformly mixed and a nonwoven fabric having a basis weight of 60 g / m ² was prepared by the card method. The non-woven fabric thus produced had a Frazier air permeability of 126 cm ³ / cm ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 170 ° C. and a linear pressure of 250 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 34 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 17 using a roll coater so that the dry solid content would be 4.0 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet produced had a Frazier air permeability of 12 cm ³ / cm ² · sec.
Met.

Comparative Example 15 [Preparation of Inkjet Recording Sheet] Using the support prepared in Example 18, a 30% aqueous dispersion of powder silica (Nipsil E220A, manufactured by Nippon Silica Industry Co., Ltd.) was used as an ink receiving layer composition. 333 parts of average particle diameter 1.0 μm, 30 parts of polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd.) as an adhesive, cationic resin (Polyfix 601, cationic charge amount of 6.9 meq./g, Showa High) as a dye fixing agent. (Molecular Co., Ltd.) 10% solid concentration with 30 parts as the main component
Dry solid content of the aqueous dispersion of
An inkjet recording sheet was prepared by coating and drying so as to be g / m ² and finishing by machine calendering. The inkjet recording sheet produced had a Frazier air permeability of 22.
It was cm ³ / cm ² · sec.

Example 19 [Preparation of support] 85 parts of polyester fiber (fiber diameter 2 denier, fiber length 5 mm), low-melting point polyester fiber (fiber diameter 4 denier, fiber length 5 mm) as a heat-bonding fiber,
An aqueous slurry consisting of 15 parts of a melting point of 110 ° C.),
A non-woven fabric having a basis weight of 50 g / m ² was prepared using a wet papermaking method.
The non-woven fabric produced has a Frazier air permeability of 145 cm ³ / cm ²
・ It was sec. Subsequently, the nonwoven fabric is heated to a heating temperature of 125.
Thermal calendering is performed under the conditions of ℃ and linear pressure of 50 kg / cm.
It was used as a support for an inkjet recording sheet. The Frazier air permeability of the support was 68 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 17 using an air knife coater so that the dry solid content would be 5.0 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet produced had a Frazier air permeability of 46 cm ³ / cm ²
・ It was sec.

Comparative Example 16 [Preparation of Inkjet Recording Sheet] The support prepared in Example 19 was used, and as the ink-receiving layer composition, instead of the colloidal silica used in Example 19, another primary particle size was used. Large colloidal silica (Snowtex PS
An inkjet recording sheet was produced in the same manner as in Example 19 except that 100 parts of T-3, manufactured by Nissan Kagaku Co., Ltd., and having a primary particle diameter of 300 ± 30 nm) were used. The inkjet recording sheet produced had a Frazier air permeability of 58 cm ³ / cm ² · s.
It was ec.

Example 20 [Preparation of support] 60 parts of polyester fiber (fiber diameter 0.5 denier, fiber length 5 mm), low melting point polyester fiber (fiber diameter 2 denier, fiber length 5 m) as a heat-bonding fiber
m, melting point 110 ° C.) 40 parts of an aqueous slurry was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by a wet papermaking method. The non-woven fabric produced has a Frazier air permeability of 82 cm ³ / c.
It was m ² · sec. Then, the nonwoven fabric is heated to a heating temperature of 120.
Thermal calendering was carried out under the conditions of ° C and a linear pressure of 100 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 15 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] 100 parts of cationic colloidal silica (Snowtex-AK (3), Nissan Chemical Co., primary particle size 10 to 20 nm) as an ink receiving layer composition, polyvinyl alcohol as an adhesive. (PVA 117, manufactured by Kuraray Co., Ltd.) 30 parts, a cationic resin (Smiley's resin 10 as a dye fixing agent
01, cation charge amount 3.5 meq./g, Sumitomo Chemical Co., Ltd.) 3
An aqueous dispersion containing 0 parts as a main component and having a solid content concentration of 10% was coated on the above-mentioned support using a roll coater so that the dry solid content was 2.0 g / m ² , dried, and machine calendered. An ink jet recording sheet was prepared by finishing. The inkjet recording sheet produced has a Frazier air permeability of 4 cm.
^{It was 3} / cm ² · sec.

Example 21 [Preparation of support] 70 parts of polyester fiber (fiber diameter: 0.5 denier, fiber length: 5 mm), polyester-nylon 6 composite fiber (fiber diameter: 4 denier, as a heat-bonding fiber)
An aqueous slurry consisting of 30 parts of a fiber length of 5 mm and a melting point of 190 ° C. was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by a wet papermaking method. The Frazier air permeability of the produced non-woven fabric is
It was 98 cm ³ / cm ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 200 ° C. and a linear pressure of 150 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 30 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 20 in the same manner as in Example 20 so that the dry solid content was 2.5 g / m ^2. An ink jet recording sheet was prepared by working, drying and machine calendering. The inkjet recording sheet produced had a Frazier air permeability of 23 cm ³ / cm ² · sec.
Met.

The above Examples 16 to 21 and Comparative Examples 13 to
The inkjet recording sheet prepared in 16 was evaluated according to the above-described evaluation method, and the results are shown in Table 3.

[0148]

[Table 3]

From the results shown in Table 3, the ink jet recording sheets of the present invention shown in Examples 16 to 21 use ultrafine inorganic pigments having a particle size of 100 nm or less, and the Frazier air permeability of the recording sheets falls within the range of the invention. Since it was within the range, the ink absorbency, the image density, and the sharpness were good, and the dot shape coefficient was small and the recording dot shape was close to a perfect circle.

Comparative Example 12 was not listed in Table 3 because the ink jet recording sheet could not be prepared as described above.

Comparative Example 13 is an inkjet recording sheet prepared by using the nonwoven fabric prepared in Example 16 as a support without thermal calendering. The recording sheet had a Frazier air permeability of 170 cm ³ / It was as high as cm ² · sec, the recorded image lacked in clarity, and the dot shape factor was inferior.

In Example 17 and Comparative Example 14, the same non-woven fabric was used and the heat calendering treatment conditions were changed, but in Comparative Example 14 the treatment conditions were low, and Since the Frazier air permeability was out of the range of the present invention, the recorded image lacked sharpness and the dot shape factor was inferior.

In Example 18 and Comparative Example 15, the same support was used and the material of the ink receiving layer composition was changed, but Comparative Example 15 uses silica having a large particle size. However, the image density and dot shape coefficient were poor.

In Example 19 and Comparative Example 16, the same support was used and the material of the ink receiving layer composition was changed, but Comparative Example 16 is outside the scope of the present invention and has a large particle size colloidal. Due to the use of silica, the inkjet recording sheet produced had a Frazier air permeability of 58 cm ³
/ Cm ² · sec, which is outside the scope of the present invention, lacked in sharpness in characteristics, and had a large dot shape coefficient.

Example 22 [Preparation of support] 60 parts of polyester fiber (fiber diameter 0.5 denier, fiber length 5 mm), NB with freeness 480 ml
An aqueous slurry composed of 40 parts of KP was prepared and a nonwoven fabric having a basis weight of 50 g / m ² was prepared by using a wet papermaking method. The Frazier air permeability of the produced non-woven fabric was 45 cm ³ / cm ² · sec. Subsequently, this non-woven fabric is heated at a heating temperature of 250 ° C. and a linear pressure of 30.
A heat calendar treatment was performed under the condition of 0 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 13 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] A 10% aqueous dispersion of columnar cationic colloidal silica (particle size; width 40 nm × length 100) was used as the ink receiving layer composition.
~ 300 nm) 1000 parts, 10% aqueous solution of polyvinyl alcohol as an adhesive (PVA 117, manufactured by Kuraray Co., Ltd.)
100 parts, 60% aqueous solution of cationic resin as a dye fixing agent (Polyfix 601, cationic charge amount 6.9 me
q./g, manufactured by Showa Highpolymer Co., Ltd.) An aqueous dispersion containing 16.7 parts as a main component and having a solid content concentration of 15% was applied to a dry solid content of 3.0 g / m ² using a roll coater. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet thus produced had a Frazier air permeability of 5 cm ³ / cm ² · sec.

Comparative Example 17 [Preparation of support] 75 parts of polyester fiber (fiber diameter: 2 denier, fiber length: 5 mm), NBK having a freeness of 480 ml
An aqueous slurry containing 25 parts of P was prepared and a non-woven fabric having a basis weight of 50 g / m ² was prepared using a wet papermaking method. The Frazier air permeability of the produced nonwoven fabric was 175 cm ³ / cm ² · sec. This non-woven fabric was not subjected to thermal calender treatment and was used as it was as a support for an inkjet recording sheet.

[Preparation of Inkjet Recording Sheet] A non-thermocalendered non-woven fabric was coated with the ink receiving layer coating solution used in Example 22 in a dry solid content of 3.0 g / m ² as in Example 22. Was coated, dried and machine-calendered to prepare an inkjet recording sheet. The Frazier air permeability of the manufactured inkjet recording sheet was 166 cm ³ / cm ² · sec.

Example 23 [Preparation of support] 90 parts of polyester fiber (fiber diameter 0.5 denier, fiber length 5 mm), polypropylene-ethylene vinyl acetate composite fiber (fiber diameter 2
An aqueous slurry consisting of 10 parts of denier, fiber length 5 mm, melting point 97 ° C.) was prepared, and the basis weight was 50 g /
A m ² non-woven fabric was prepared. The non-woven fabric thus produced had a Frazier air permeability of 65 cm ³ / cm ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 100 ° C. and a linear pressure of 50 kg / cm to obtain a support for an inkjet recording sheet. Frazier air permeability of the support is 30 cm ³ / cm ²
・ It was sec.

[Preparation of Inkjet Recording Sheet] As a composition of the ink receiving layer, about 6.2% by weight of aluminum oxide hydrate of acicular acicular colloidal silica in terms of Al ₂ O ₃ relative to silica (in terms of SiO ₂ ). 10% aqueous dispersion of acicular cation-modified colloidal silica modified by (particle size;
Width 10 to 20 nm x length 50 to 200 nm) 1000
Parts, 50 parts of a 10% aqueous solution of polyvinyl alcohol (PVA 117, manufactured by Kuraray Co., Ltd.) as an adhesive, and a 60% aqueous solution of a cationic resin as a dye fixing agent (Polyfix 60).
1, cation charge 6.9 meq./g, Showa High Polymer Co., Ltd.) 1
An aqueous dispersion containing 6.7 parts as a main component and having a solid content concentration of 10% was coated on the above-mentioned support using a size press so as to have a dry solid content of 1.0 g / m ^2, and dried, An ink jet recording sheet was prepared by machine calendering. The Frazier air permeability of the manufactured inkjet recording sheet is
It was 28 cm ³ / cm ² · sec.

Comparative Example 18 [Production of Support] The nonwoven fabric produced in Example 23 was subjected to thermal calendaring under the conditions of a heating temperature of 90 ° C. and a linear pressure of 40 kg / cm to obtain a support for an ink jet recording sheet. The Frazier air permeability of the support was 60 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 23 in the same manner as in Example 23 so that the dry solid content was 1.0 g / m ^2. An ink jet recording sheet was prepared by working, drying and machine calendering. The inkjet recording sheet produced had a Frazier air permeability of 57 cm ³ / cm ² · sec.
Met.

Example 24 [Preparation of support] 80 parts of polyester fiber (fiber diameter 1.4 denier, fiber length 51 mm), polypropylene fiber (fiber diameter 3 denier, fiber length 38 to 5) as a heat-bonding fiber
20 parts of 1 mm and a melting point of 153 ° C.) were uniformly mixed to prepare a nonwoven fabric by the card method. The non-woven fabric thus produced had a Frazier air permeability of 126 cm ³ / cm ² · sec. continue,
This non-woven fabric was subjected to thermal calendaring under the conditions of a heating temperature of 170 ° C. and a linear pressure of 250 Kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 34 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 23 using a roll coater so that the dry solid content was 3.0 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet produced had a Frazier air permeability of 15 cm ³ / cm ² · sec.
Met.

Example 25 [Preparation of support] 85 parts of polyester fiber (fiber diameter: 2 denier, fiber length: 5 mm), low melting point polyester fiber (fiber diameter: 4 denier, fiber length: 5 mm) as a heat-bonding fiber
An aqueous slurry consisting of 15 parts of a melting point of 110 ° C.),
A non-woven fabric having a basis weight of 50 g / m ² was prepared using a wet papermaking method.
Frazier air permeability of the produced non-woven fabric is 145 cm ³ / c
It was m ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 125 ° C. and a linear pressure of 50 kg / cm to obtain a support for an inkjet recording sheet.
The Frazier air permeability of the support was 68 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink-receiving layer used in Example 23 using an air knife coater so that the dry solid content would be 5.0 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The inkjet recording sheet produced had a Frazier air permeability of 32 cm ³ / cm ²
・ It was sec.

Example 26 [Preparation of Inkjet Recording Sheet] The support prepared in Example 25 was used, and as the ink receiving layer composition, the needle-like cation-modified colloidal silica used in Example 25 was replaced by needles. Of 10% aqueous colloidal silica dispersion (particle size; aggregate having a width of 10 to 20 nm and a length of 50 to 200 nm) is used in an amount of 1000 parts, and a dry solid content of 8.0 g / m ² is applied. An inkjet recording sheet was produced in the same manner as in Example 25 except that the above was performed. The inkjet recording sheet produced had a Frazier air permeability of 25 cm ³ / cm ² · sec.
Met.

Example 27 [Preparation of support] 60 parts of polyester fiber (fiber diameter 0.5 denier, fiber length 5 mm), low melting point polyester fiber (fiber diameter 2 denier, fiber length 5 m) as a heat-adhesive fiber
m, melting point 110 ° C.) 40 parts of an aqueous slurry was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by a wet papermaking method. The non-woven fabric produced has a Frazier air permeability of 82 cm ³ / c.
It was m2 · sec. Then, the nonwoven fabric is heated to a heating temperature of 120.
Thermal calendering was carried out under the conditions of ° C and a linear pressure of 100 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 15 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] As an ink-receiving layer composition, the ink-receiving layer coating liquid used in Example 25 was applied by a roll coater to a dry solid content of 1.5 g / m ^2. Then, it was dried and machine-calendered to prepare an inkjet recording sheet. The produced inkjet recording sheet has a Frazier air permeability of 6 cm ³ / c.
It was m ² · sec.

Example 28 [Preparation of Inkjet Recording Sheet] The support prepared in Example 27 was used, and the acicular cation-modified colloidal silica used in Example 27 was used instead of the acicular cation-modified colloidal silica used in Example 27 as an ink receiving layer composition. 30% of cationic colloidal silica
Using 333 parts of an aqueous dispersion (primary particle size; 80 nm),
An inkjet recording sheet was produced in the same manner as in Example 27 except that the dry solid content was 7.5 g / m ² . The Frazier air permeability of the produced inkjet recording sheet was 10 cm ³ / cm ² · sec.

Example 29 [Preparation of support] 70 parts of polyester fiber (fiber diameter: 0.5 denier, fiber length: 5 mm), polyester-nylon 6 composite fiber (fiber diameter: 4 denier, as a heat-adhesive fiber)
An aqueous slurry consisting of 30 parts of a fiber length of 5 mm and a melting point of 190 ° C. was prepared, and a non-woven fabric having a basis weight of 50 g / m ² was prepared by a wet papermaking method. The Frazier air permeability of the produced non-woven fabric is
It was 98 cm ³ / cm ² · sec. Subsequently, this non-woven fabric was subjected to a heat calendar treatment under the conditions of a heating temperature of 200 ° C. and a linear pressure of 150 kg / cm to prepare a support for an inkjet recording sheet. The Frazier air permeability of the support was 30 cm ³ / cm ² · sec.

[Preparation of Inkjet Recording Sheet] The above support was coated with the coating liquid for the ink receiving layer used in Example 27 in the same manner as in Example 27 so that the dry solid content was 2.0 g / m ^2. An ink jet recording sheet was prepared by working, drying and machine calendering. The inkjet recording sheet produced had a Frazier air permeability of 20 cm ³ / cm ² · sec.
Met.

The above Examples 22 to 29 and Comparative Examples 17 to
The inkjet recording sheet prepared in 18 was evaluated based on the evaluation method described above, and the results are shown in Table 4.

[0174]

[Table 4]

From the results shown in Table 4, the ink jet recording sheets of the present invention shown in Examples 22 to 29 use specific ultrafine inorganic pigments, especially non-spherical cationic colloidal silica, and have a Frazier air permeability of the recording sheets. Since it was within the range of the invention, the ink absorbency, the image density, and the sharpness were good, the dot shape coefficient was small, and the recording dot shape was close to a perfect circle.

In Comparative Example 17, the nonwoven fabric prepared in Example 22 was used as a support without thermal calendering, and an ink jet recording sheet was prepared. The Frazier air permeability of the recording sheet was 166 cm ³ / It was as high as cm ² · sec, the recorded image lacked in clarity, and the dot shape factor was inferior.

In Example 23 and Comparative Example 18, the same non-woven fabric was used and the heat calendering treatment conditions were changed, but in Comparative Example 17, the treatment conditions were low, and Since the Frazier air permeability was out of the range of the present invention, the recorded image lacked sharpness and the dot shape factor was inferior.

In Example 25 and Example 26, the same support was used and the material of the ink receiving layer composition was changed. However, since Example 26 uses acicular colloidal silica, The sharpness of the recorded image was slightly low, and the dot shape factor was also relatively large.

In Example 27 and Example 28, the same support was used and the material of the ink receiving layer composition was changed, but since Example 28 uses spherical colloidal silica, The dot shape factor was rather large.

[0180]

The ink jet recording sheet of the present invention is
A non-woven fabric or a non-woven fabric treated under specific heat calendering conditions is used as a support, and an ink-receiving layer component mainly composed of a specific ultrafine particle inorganic pigment, particularly non-spherical cationic colloidal silica and a binder is used, An inkjet recording sheet having a Frazier air permeability within a specific range, excellent in ink absorption without uneven bleeding of ink, high density and sharpness of a recorded image,
It is an inkjet recording sheet that can obtain a recording dot close to a perfect circle.

Continuation of front page (31) Priority claim number Japanese Patent Application No. 5-147522 (32) Priority date Hei 5 (1993) June 18 (33) Country of priority claim Japan (JP)

Claims (11)

[Claims] 1. An ink jet recording sheet comprising an ink-receiving layer coated on a support, wherein the support is made of a non-woven fabric, and the ink-receiving layer component is mainly 100 nm.
The recording sheet according to JIS L109, which is composed of an ultrafine inorganic pigment having the following primary particle diameter and a binder,
Frazier air permeability specified in 6 is 100 cm ³ / cm ² · sec
An inkjet recording sheet characterized by the following: 2. The ink jet recording sheet according to claim 1, wherein the ultrafine particle inorganic pigment is a non-spherical cationic colloidal silica. 3. The non-spherical cationic colloidal silica comprises:
A needle-shaped or fibrous material.
The inkjet recording sheet described. 4. The inkjet recording sheet according to claim 1, wherein the non-woven fabric is a wet non-woven fabric. 5. The support has a Frazier air permeability of 350 cm.
^{It is 3} / cm ² · sec or less, 1 or 4 characterized by the above-mentioned.
The inkjet recording sheet described. 6. An ink-jet recording sheet comprising an ink-receiving layer coated on a support, the support being treated under a thermal calendar condition of a heating temperature of 100 to 250 ° C. and a linear pressure of 50 to 300 kg / cm. The ink receiving layer component is mainly composed of an ultrafine particle inorganic pigment having a primary particle diameter of 100 nm or less and a binder, and the Frazier air permeability of the recording sheet defined by JIS L1096 is 50 cm ³ / cm ² ·. An inkjet recording sheet characterized by having a length of sec or less. 7. The ink jet recording sheet according to claim 6, wherein the ultrafine particle inorganic pigment is a non-spherical cationic colloidal silica. 8. The non-spherical cationic colloidal silica comprises:
The needle-shaped or fiber-shaped material.
The inkjet recording sheet described. 9. The ink jet recording sheet according to claim 6, wherein the non-woven fabric is composed of an organic synthetic fiber and a heat adhesive fiber. 10. The inkjet recording sheet according to claim 6, wherein the non-woven fabric is a wet non-woven fabric. 11. The support has a Frazier air permeability of 100.
cm ³ / cm ² · sec or less, claim 1,
9. The inkjet recording sheet according to any one of 9 and 10.