JP3012580B2 - Inkjet recording sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet mainly using an aqueous ink. More specifically, the present invention relates to an ink jet recording sheet from which an excellent image can be obtained.

[0002]

2. Description of the Related Art In an ink jet recording system, fine droplets of ink are made to fly and adhere to a recording sheet such as paper according to various operating principles, thereby recording images and characters. Inkjet printers are notable for their high-speed printability and low-noise properties, great flexibility in recording patterns, and no need for development-fixing, and that they can form complex images accurately and quickly. In recent years, it has rapidly spread in various applications as a hard copy creation device for image information such as characters and various figures created by a computer. Also, by using a plurality of ink nozzles, it is easy to perform multicolor recording.
The color image formed by the multi-color ink jet method can obtain a record comparable to the multi-color printing by the plate making method and the printing by the color photographic method, and in applications where the number of copies is small, It is being widely used because it is cheaper than photographic technology.
In recent years, the fields of application of ink jet printers, which have attracted particular attention, include full color image recording such as production of color printing plates in the printing field requiring image quality close to photographs, and output of design images in the design department. Further, image information created by a computer is recorded on a transparent recording sheet by an ink jet printer, and is used as a document of an OHP (overhead projector) for a presentation in a meeting or the like.

As recording sheets used in the ink jet recording system, efforts have been made in terms of apparatuses and ink compositions so that ordinary printing or high quality paper for writing or coated paper can be used. However, as the performance of ink jet recording apparatuses has been improved and the applications thereof have been increased, such as higher speed, higher definition, and full color, recording sheets have been required to have more advanced characteristics. That is,
As the recording sheet, the density of print dots is high, the color tone is bright and vivid, the ink absorption is fast,
Even when the print dots overlap, it is required that the ink does not flow out or bleed, that the diffusion of the print dots in the horizontal direction is not unnecessarily large, and that the periphery is sharp and not blurred. In particular, in the case of color printing, not only single-color printing of yellow, magenta, cyan, and black, but also multi-color printing in which these colors are superimposed is performed, and extremely strict performance is required because the ink adhesion amount is further increased.

Further, when a conventional ink absorbing layer is used for OHP, there is a problem that even if a transparent support is used, the porous ink absorbing layer deteriorates light transmittance. Further, when the surface of the ink absorbing layer is non-porous, the light transmittance is improved, but the aqueous ink receiving ability is poor,
After the image recording and printing, the ink remains on the sheet surface for a long time, causing a problem that the ink is rubbed and stains the image when the sheet is conveyed in the printer.

[0005] In order to solve such problems, many ink jet recording sheets provided with a transparent ink absorbing layer having high ink receptivity have been proposed. For example, Japanese Patent Application Laid-Open No. 60-168651 discloses the use of a water-soluble polymer based on polyvinyl alcohol and polyacrylic acid.
Japanese Patent Application Laid-Open No. 62689/85 uses hydroxyethyl cellulose, Japanese Patent Application Laid-Open No. 61-181679 uses a mixture of carboxymethyl cellulose and polyethylene oxide, and Japanese Patent Application Laid-Open No. 61-193879 uses a mixture of water-soluble cellulose and polyvinylpyrrolidone. Showa 6
Japanese Patent Application Laid-Open No. 2-263804 proposes a receiving layer formed from an aqueous solution of gelatin having a specific pH, and Japanese Patent Application Laid-Open No. 1-146784 proposes the use of a mixture of gelatin and a surfactant.

[0006] The ink jet recording sheets described in these publications have excellent light transmittance and improved ink receptivity, but are still insufficient, and in particular, the dot reproducibility is insufficient. It could not be used as a color hard copy material for image quality.

[0007] EP-A-380133 states that
A recording medium and an image forming method using the same are described. The recording medium includes a base material and an ink receiving layer provided on the base material, and the ink receiving layer contains a reaction product of a gelling agent and a coupling agent. In the image forming method, an image is formed by applying inkjet recording to the recording medium.

[0008] European Patent Publication No. 445372 discloses that
A recording medium for inkjet recording is disclosed. The recording medium includes a polyolefin-coated substrate having an ink receiving layer formed on an upper surface thereof, and the ink receiving layer contains a mixture of gelatin and rice starch.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording sheet having excellent high quality.

As inks for ink-jet recording,
In order to prevent clogging of the ink in the conduits and nozzles in the printer head and to improve the ejection characteristics, inks mainly composed of water and polyhydric alcohol are mainly used. It is important that the ink receiving layer absorbs such inks quickly and does not diffuse them.

[0011]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by providing a specific ink receiving layer on a support, high-quality ink-jet recording has been achieved. We found what we could get for the sheet.

According to a first aspect of the present invention, in an ink jet recording sheet provided with an ink receiving layer on a support, the ink receiving layer comprises a low molecular weight gelatin having a molecular weight of 100,000 or less as a solid content of a solid content. 30% by weight or more of the total solid content, 0.1 to 1% by weight of mucochloric acid based on the gelatin content, and carboxymethyl cellulose having a molecular weight of 100,000 or less and a degree of etherification of 1% or less. An ink jet recording sheet containing the components is provided.

According to a second aspect of the present invention, in an ink jet recording sheet having an ink receiving layer provided on a support, the ink receiving layer comprises a polyoxyalkylene glycol containing an ethylene oxide chain, a polyvalent carboxylic acid,
An ink jet recording sheet containing a polymer compound obtained by reacting at least one compound selected from a polycarboxylic anhydride, a polycarboxylic lower alkyl ester and an organic polyisocyanate is provided.

Further, the present inventors have proposed an ink receiving layer surface C
IELAB (CommissionInternationale de 1 “Echair
age ”When the lightness index L and the perceived chromaticity index a and b according to the recommended L ^* a ^* b ^* color abbreviations are within a specific range,
It was found that the whiteness was excellent visually, the sharpness of the image was high, and the color reproducibility was good.

That is, according to a third aspect of the present invention, in an ink jet recording sheet provided with an ink receiving layer on at least one surface of a support, the surface of the ink receiving layer is
According to the measurement method specified in JIS-Z8722, JIS
The lightness index L and the perceived chromaticity index a and b of the surface defined by S-Z8730 are respectively 87 or more, -2 to +
2 and -3 to +3 are provided.

According to a fourth aspect of the present invention, in an ink jet recording sheet provided with an ink receiving layer on at least one surface of a support, the surface of the support on which the ink receiving layer is coated is defined by JIS-Z8722. According to the measurement method to be performed, the lightness index L defined by JIS-Z8730,
The perceived chromaticity indices a and b are respectively 90 or more, -2 to +
2 and -5 to 0 are provided.

According to a fifth aspect of the present invention, in an ink jet recording sheet provided with an ink receiving layer on at least one surface of a support, the surface of the ink receiving layer is JIS.
JIS-Z according to the measurement method specified in -Z8722
The value of the surface lightness index L and the perceived chromaticity index a and b defined by 8730 are respectively 87 or more, -2 to +2 and -3 to +3, and the ink receiving layer component is mainly non- An ink jet recording sheet comprising spherical cationic colloidal silica and a binder is provided.

First, a first aspect of the present invention will be described. As the gelatin contained in the ink receiving layer, gelatin having a molecular weight of 100,000 or less is used. If the molecular weight exceeds 100,000, the compatibility with carboxymethyl cellulose deteriorates, and the uniformity of the image density of the ink receiving layer decreases.

As the gelatin, any gelatin can be used as long as it is made of animal collagen, but gelatin made of collagen obtained from pig skin, cow skin and bovine bone is preferred. Further, the kind of gelatin is not particularly limited, but lime-treated gelatin, acid-treated gelatin, gelatin derivatives (for example, JP-B-38-4854,
JP-A-39-5514, JP-A-40-12237, JP-A-42-26345, U.S. Pat.
Nos. 753, 2594293 and 261
No. 4928, No. 2763639, No. 31
No. 18766, No. 3132945, No. 3
186,846, 3,332,553, British Patent No. 861,414, and No. 1,333,189) can be used alone or in combination.

The jelly strength of gelatin (PAGI method, Bloom-type jelly strength meter) is 150 g or more,
In particular, the weight is preferably 200 to 300 g.

The coating amount of the ink-receiving layer is not particularly limited, is preferably 3 to 50 g / m ² as solid content, more preferably from 5 to 30 g / m ^2. If the coating amount of the ink receiving layer is less than 3 g / m ² , the ink receiving property is poor, and the ink overflows from the receiving layer after printing. If it exceeds 50 g / m ² , the ink receptivity is improved, but problems such as cracking and curling of the ink receiving layer occur.

The ratio of mucochloric acid to gelatin is
Preferably, the solid content is 0.1 to 1.0% by weight.
If the proportion of mucochloric acid is less than 0.1% by weight, the coating of the receiving layer is insufficiently cured, and the receiving layer may flow out after printing. On the other hand, if it exceeds 1.0% by weight, ink receptivity is poor and dot reproducibility deteriorates.

The molecular weight of carboxymethyl cellulose is 1
Below 100,000, the degree of etherification is below 1%. Those having a molecular weight of more than 100,000 or those having a degree of etherification of more than 1% have high viscosity and deteriorate coatability.

The ratio of carboxymethylcellulose to gelatin is not particularly limited in the range constituting the present invention, but in order to improve ink receptivity and dot reproducibility, the weight ratio of carboxymethylcellulose to gelatin is from 5/95 to 70/70. It is preferably in the range of 30 and 1
More preferably, it is in the range of 0/90 to 60/40.

A surfactant may be added to the ink receiving layer in order to improve dot reproducibility in addition to the binder. Surfactants used are anionic,
Any of a cationic type, a nonionic type, and a betaine type may be used, and a low molecular weight type or a high molecular type may be used. 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 amount of the surfactant to be added is preferably 0.001 g to 5 g, more preferably 0.01 to 3 g, based on 100 g of the binder constituting the ink receiving layer in terms of solid content.

In the ink receiving layer, in addition to the above-mentioned surfactants, inorganic pigments, coloring dyes, coloring pigments, fixing agents for ink dyes, ultraviolet absorbers, antioxidants, pigment dispersants, defoamers, Leveling agent, preservative, optical brightener, viscosity stabilizer,
Various known additives such as a pH adjuster can also be added.

As a method of applying the coating liquid for the ink receiving layer, for example, a commonly used coating method such as a slide hopper method, a curtain method, an extrusion method, an air knife method, a roll coating method, and a rod bar coating method is used. .

The ink receiving layer is provided on at least one side of the support, but may be provided on both sides of the support for the purpose of preventing curling.

The thickness of the polyester film that can be used as the support is not particularly limited, but is preferably 10 to 200 μm in view of handling properties and suitability for paper passing of a printer.
Are preferred.

The thickness of the polyolefin resin-coated paper that can be used as a support is not particularly limited, either.
50 to 3 for easy handling and printer
Those having a size of about 00 μm are preferred.

The base paper for the resin-coated paper is not particularly limited.
Generally used paper can be used, but preferably,
For example, a smooth base paper as used for a photographic support is preferable. As the pulp constituting the base paper, a natural pulp, a recycled pulp, a synthetic pulp, or the like is used alone or in combination of two or more. The base paper is blended with additives generally used in papermaking, such as a sizing agent, a paper strength enhancer, a filler, an antistatic agent, a fluorescent whitening agent, and a dye. Furthermore,
Surface sizing agent, surface paper strength agent, optical brightener, antistatic agent,
A dye, an anchoring agent or the like may be applied on the surface.

The base paper preferably has good surface smoothness, for example, by applying pressure with a calender or the like during or after papermaking, and preferably has a basis weight of 30 to 250 g / m ² .

As the polyethylene resin, low density polyethylene, medium density polyethylene, high density polyethylene or a mixture thereof can be used. The low-density polyethylene referred to here has a density of 0.915 to 0.930 g / cm ³ and is usually produced by a high-pressure method. On the other hand, high density polyethylene has a density of 0.950 g / cm
^Three or more, usually manufactured by a low-pressure method or a medium-pressure method. These polyethylene resins having various densities and melt flow rates can be used alone or in combination of two or more.

The structure of the resin layer of the resin-coated paper may be either a single layer or a multilayer of two or more layers. Also in this case, the above-mentioned polyolefin resins can be used alone or in combination of two or more. Further, the respective layers of the multilayer may have different compositions or the same composition. As a method of forming a multilayer resin layer, any of a coextrusion coating method and a sequential coating method may be adopted.

The thickness of the coating resin layer of the resin-coated paper is not particularly limited, but it is generally coated to a thickness of 5 to 50 μm on the surface only or on both the front and back surfaces.

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 and arachidic amide;
Fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, Irganox 1010, Irganox 1
076, antioxidants, blue pigments and dyes such as cobalt blue, ultramarine blue, cecilian blue, and phthalocyanine blue; magenta pigments and dyes such as cobalt violet, fast violet, and manganese purple; fluorescent brighteners; and ultraviolet absorbers. Various additives can be added in appropriate combination.

The resin-coated paper is produced by a so-called extrusion coating method in which a heated and melted polyethylene resin is cast on a running base paper. Further, in order to improve the adhesiveness between the resin and the base paper, it is preferable to perform an activation treatment such as a corona discharge treatment or a flame treatment on the base paper before coating the resin on the base paper. The surface (surface) of the support on which the ink receiving layer is applied has a glossy surface, a matte surface, and the like, and a glossy surface is particularly preferably used, depending on the use. It is not always 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, if necessary, both the front and back surfaces can be subjected to an activation treatment such as a corona discharge treatment or a flame treatment.

The support may be provided with an antistatic or curl-preventive back coat layer for improving transportability. In the back coat layer, an inorganic antistatic agent,
An organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like can be appropriately combined and added.

In the first aspect, gelatin absorbs the ink quickly and prevents the drying and fixing time from being lengthened by the ink remaining on the sheet surface for a long time. In addition, by limiting the amount of mucochloric acid to 0.1 to 1.0% by weight of solid content based on gelatin,
The degree of crosslinking of gelatin is controlled to impart appropriate water absorption and water resistance. Further, carboxymethylcellulose has an effect of preventing excess diffusion of ink dots by suppressing swelling of the gelatin film.

Next, a second aspect of the present invention will be described. One component used for producing the polymer compound contained in the ink receiving layer is polyoxyalkylene glycol. This polyoxyalkylene glycol is obtained by addition-polymerizing an alkylene oxide containing ethylene oxide to an organic active hydrogen compound having two active hydrogen groups. Specific examples of the organic active hydrogen compound include, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol,
1,4-butanediol, 1,6-hexanediol,
Neopentyl glycol, bisphenol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, butylamine, octylamine,
Laurylamine, cyclohexylamine and the like.

As the alkylene oxide used in the addition polymerization, ethylene oxide is an essential component, and in addition, propylene oxide, butylene oxide, styrene oxide and the like can be mentioned.

Specific examples of the polycarboxylic acid or its anhydride or lower alkyl ester which can be reacted with polyoxyalkylene glycol include: a) malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, Sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, itaconic acid, trimellitic acid, pyromellitic acid, dimer acid, etc. b) Monomethyl ester, dimethyl ester, monoethyl ester, diethyl ester, monopropyl ester, dipropyl ester of the above a) Propyl ester, monobutyl ester or dibutyl ester; c) anhydrides of the acids described in a) above;

Examples of the organic polyisocyanate which can be reacted with the polyoxyalkylene glycol include, for example, tolylene diisocyanate, 4,4'-methylenebis- (phenyl isocyanate), hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 4,4 4-methylenebis- (cyclohexyl isocyanate), 4,4-isopropylidene-bis- (cyclohexyl isocyanate), trimethylhexamethylene diisocyanate, and the like.

The molecular weight of the above polymer compound is 50,000
It is preferably in the range of 0 to 300,000. If the molecular weight is less than 50,000, poor water resistance,
After printing, the ink receiving layer dissolves and a clear image cannot be obtained. On the other hand, when the molecular weight exceeds 300,000, there arises a problem that the coating liquid viscosity is increased and the coating quality is deteriorated, and the coating property is lowered.

The dry coating amount of the ink receiving layer is 1 to 30 g.
/ M ² is preferred. If the coating amount of the ink receiving layer is less than 1 g / m ² , the ink receptivity is poor, so that the ink overflows from the ink receiving layer after printing, and the image is likely to be contaminated by color mixing or rubbing. On the other hand, if it exceeds 30 g / m ² , problems such as a decrease in image resolution due to sinking of ink and a curl of a recording sheet occur.

Various binders can be added to the ink-receiving layer in addition to the above-mentioned polymer compound for the purpose of improving the film strength and imparting water resistance. As the binder, starch or a modified product thereof, various gelatins, polyvinyl alcohol or a modified product thereof, water-soluble polymers such as polyvinylpyrrolidone, carboxymethylcellulose, and hydroxyethylcellulose, and latexes such as SBR latex and NBR latex are preferable.

The amount of the polymer compound is preferably 2% by weight or more based on the dry weight of the ink receiving layer.
When the amount is less than 2% by weight, the effects of the present invention are not sufficiently exhibited, and a high-quality inkjet recording sheet cannot be obtained.

A surfactant can be added to the ink receiving layer for the purpose of improving the coating property. The surfactant may be any of anionic, cationic, nonionic and amphoteric. The molecular weight of the surfactant is not particularly limited, and two or more surfactants can be added.
The amount of the surfactant added is the solid content of the ink receiving layer 100.
0.001-5 g is preferable with respect to g, More preferably, it is 0.01-3 g.

The ink receiving layer may further contain various additives described in the first aspect.

As a method of applying the coating liquid for the ink receiving layer, for example, a commonly used coating method such as a slide hopper method, a curtain method, an extrusion method, an air knife method, a roll coating method, and a rod bar coating method is used. .

The ink receiving layer is provided on at least one side of the support, but may be provided on both sides of the support for the purpose of preventing curling.

As the support, paper, metal foil, synthetic paper,
Although a cloth, a nonwoven fabric, or a composite thereof can be used, it is preferable to use a polyolefin resin-coated paper or film in terms of good image quality, gloss, smoothness, and the like. The thickness of the support is not particularly limited, but is preferably about 50 to 300 μm from the viewpoint of handling properties and suitability for paper passing of the printer.

The base paper preferably has good surface smoothness, for example, by applying a pressure with a calender or the like during or after papermaking, and preferably has a basis weight of 30 to 250 g / m ² .

The resin coating layer can be provided on one side or both sides of the base paper, but is preferably provided on both sides of the base paper from the viewpoint of preventing curling.

The resin-coated paper used as a support is produced by a so-called extrusion coating method in which a heated and melted polyolefin resin is cast on a running base paper, or by an emulsion coating method in which a resin emulsion is applied.
When the extrusion coating method is used, in order to improve the adhesiveness between the resin and the base paper, it is preferable that the base paper is subjected to an activation treatment such as a corona discharge treatment or a flame treatment before the resin is coated on the base paper. When using the emulsion coating method, it is preferable to perform a smoothing treatment such as a heat calendering treatment after the coating.

The structure of the resin layer of the resin-coated paper may be either a single layer or a multilayer of two or more layers. In this case, a polyolefin resin can be used alone or as a mixture of two or more. Further, the respective layers of the multilayer may have different compositions or the same composition. As a method of forming a multilayer resin layer, two or more layers may be applied at one time or one layer at a time.

The thickness of the resin layer of the resin-coated paper is not particularly limited, but is generally preferably from 5 to 50 μm.

The resin of the resin-coated paper contains titanium oxide and acid.
Zinc oxide, talc, calcium carbonate, kaolin clay, etc.
White pigment, stearamide, arachidic amide, etc.
Fatty acid amide, zinc stearate, calcium stearate
Cium, aluminum stearate, mug stearate
Fatty acid metal salts such as nesium, Irganox 101
0 ^TM, Irganox 1076^TMAntioxidants such as
Blue, ultramarine, cecilian blue, phthalocyanine
Blue pigments and dyes such as blue, cobalt violet,
Magenta pigments such as ast violet and manganese purple
Various additives such as dyes, optical brighteners, and ultraviolet absorbers are appropriately used.
Can be added in combination.

As the film, either a transparent film or an opaque film may be used, but a polyester film is preferred from the viewpoint of strength and cost.

The surface (surface) of the support on which the ink receiving layer is applied has a glossy surface, a matte surface, and the like, and a glossy surface is particularly preferably used, depending on the use.

Before coating the ink receiving layer, a sub-coat layer can be provided on the support in order to improve the applicability of the ink receiving layer coating solution. Various water-soluble polymers, latexes, curing agents, surfactants, and the like can be added to the subcoat layer in an appropriate combination.

As in the case of the first aspect, the support may be coated with various back coat layers in order to impart antistatic properties, transport properties, curl preventing properties, and the like. An inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like can be added to the back coat layer in an appropriate combination.

In the second aspect, a polyoxyalkylene glycol containing an ethylene oxide chain and at least one polyoxyalkylene glycol, a polycarboxylic anhydride, a polycarboxylic lower alkyl ester, and an organic polyisocyanate. By blending a high molecular compound obtained by reacting with various types of compounds into the ink receiving layer, the ink is quickly absorbed, causing color mixing at the outline of the recorded image and rubbing during sheet conveyance in the printer. An ink jet recording sheet with good image quality free from stains can be obtained.

Next, the third aspect will be described.

As a method of quantitatively measuring and displaying the color tone of an object, JIS-Z8722 and JIS-Z873 are used.
There is a method defined as 0. According to these methods,
The color tone of the object is represented by three values of L, a, and b. Here, L represents lightness, and the larger the numerical value, the higher the lightness. A represents reddish color. A larger value indicates a stronger reddish color, and a smaller value indicates a stronger greenish color. Further, b represents yellowish color. A larger value indicates a stronger yellowish color, and a smaller value indicates a stronger blueishish color.

The value of L is 87 or more. The value of L is 87
If it is smaller, the white will be grayish and dull.

The value of a is in the range of -2 to +2.
Here, if the value of a is smaller than -2, the entire image becomes greenish, which is not preferable. If it is larger than +2, the entire image becomes reddish, which is not preferable.

Further, the value of b is in the range of -3 to +3. Here, if the value of b is smaller than -3, the entire image becomes bluish, which is not preferable. If the value of b is larger than +3, the entire image becomes yellowish, which is not preferable.

In order to make the values of L, a, and b on the surface of the ink receiving layer fall within the range of the present invention, it is achieved by adding various coloring agents to the ink receiving layer.

Examples of the coloring agent to be added include a white pigment, a blue dye, a red dye, a fluorescent dye, and the like. The amount of the coloring agent to be used is appropriately changed depending on the amount of the support or the ink receiving layer to be applied. can do.

As a support, uncoated paper such as high quality paper, medium quality paper, super calendered paper, single sided base paper, tracing paper, art paper, coated paper, lightweight coated paper, finely coated paper, cast Coated paper such as coated paper, plastic film such as polyester film and cellulose acetate film, synthetic paper such as foamed polyolefin synthetic paper, foamed polyester synthetic paper, polyolefin resin-coated paper, resin-impregnated paper, nonwoven fabric, cloth and these Complexes can be used.

In the ink receiving layer, various pigments and resins are used together with other additives in order to enhance ink absorption. Examples of the pigment added for such a purpose include silica, colloidal silica, alumina, alumina sol, magnesium carbonate, calcium carbonate, titanium oxide, and zinc oxide. Further, as the resin, starch and its modified products, gelatin and its modified products, polyvinyl alcohol and its modified products, polyvinylpyrrolidone, carboxymethylcellulose, hydroxyethylcellulose, sodium polyacrylate, sodium alginate, water-soluble resins such as polyacrylamide, Resin emulsions such as acrylic emulsion, vinyl acetate emulsion, SBR latex and NBR latex are used. Further, the ink receiving layer, if necessary, anionic, cationic, nonionic, amphoteric surfactants, dye fixing agents, ultraviolet absorbers, antioxidants, defoamers, leveling agents, preservatives, Additives such as a viscosity stabilizer and a pH adjuster may be added.

The dry coating amount of the ink receiving layer is 1 to 30 g.
/ M ² . When the coating amount of the ink receiving layer is less than 1 g / m ² , the ink receiving property is inferior, so that the ink overflows from the ink receiving layer after printing, and the image is liable to be contaminated by color mixing or rubbing. Also, 30g
If it exceeds / m ² , problems such as lowering of image resolution due to sinking of ink and curling of a recording sheet occur.

The coating method of the coating liquid for the ink receiving layer includes a rod method, a wire bar method, a slide hopper method,
General coating methods such as a curtain method, an extrusion die method, an air knife method, a roll method, and a blade method are used.

In the ink jet recording sheet of the present invention, the ink receiving layer may be a single layer or a multilayer of two or more layers. In the case of a multilayer, each layer can have a different composition or the same composition. In the case of forming a multilayer, two or more layers may be applied at a time or one layer at a time.

In the ink jet recording sheet of the present invention, the ink receiving layer is provided on at least one side of the support, but may be provided on both sides of the support for the purpose of performing double-sided printing or preventing curling. good.

In the third aspect, by setting the values of the lightness index L and the perceived chromaticity indexes a and b of the surface of the ink receiving layer within specific ranges, the image receiving layer has visually excellent whiteness, and has a high image quality. An ink jet recording sheet having high sharpness and good color reproducibility can be obtained.

Next, the fourth aspect will be described. The use of a polyolefin resin-coated paper is preferred because the support has high whiteness, gloss and smoothness and good image quality can be obtained.

The value of L is 90 or more. Here, when the value of L is smaller than 90, the ink jet recording sheet becomes grayish and the color of the image becomes dull.

The value of a is in the range of -2 to +2.
Here, if the value of a is smaller than -2, the ink jet recording sheet is undesirably greenish, and if it is larger than +2, the ink jet recording sheet is undesirably reddish.

Further, the value of b is in the range of -5 to 0.
Here, if the value of b is smaller than -5, the ink jet recording sheet is undesirably bluish, and if it is larger than 0, the ink jet recording sheet is undesirably yellowed.

In order for the values of L, a, and b on the surface of the support on which the ink receiving layer is coated to fall within the range of the present invention, various types of base paper layers, intermediate layers or resin coating layers may be used. This is achieved by adding a coloring agent. The colorant to be added is preferably one having excellent light resistance and heat resistance, and can be used by appropriately changing the addition amount according to the color tone and coating amount of the ink receiving layer. Examples of such coloring agents include titanium dioxide, zinc oxide, barium sulfate, calcium carbonate, talc, kaolin, clay, silica, alumina, and magnesium oxide in white, and cobalt blue, ultramarine, cecilian blue, and phthalocyanine blue in blue. For red, quinacridone red, anthraquinone red, bisazo red, isoindolinone red, etc., for yellow, bisazo yellow,
Pigments and dyes such as cobalt violet, fast violet, and manganese purple in purple, such as isoindolinone yellow, and fluorescent dyes such as stilbene, distilbene, benzoxazole, coumarin, imidazole, benzimidazole, and pyrazoline are used. Can be used.

The base paper for the polyolefin resin-coated paper as the support is not particularly limited, and generally used paper can be used. As the pulp constituting such base paper, natural pulp, recycled pulp, synthetic pulp or the like is used alone or in combination. In addition to the above pigments and dyes, the base paper may contain additives generally used in papermaking, such as a sizing agent, a paper strength enhancer, a fixing agent, a conductive agent, and a pH adjuster. And the base paper contains pigments, dyes, water-soluble resins, resin emulsions, sizing agents, paper strength agents,
A conductive agent, an anchoring agent or the like may be applied or impregnated. Furthermore, to improve the surface smoothness of these base papers, during or after paper making machine calendar, heat calendar, soft calendar, super calendar, etc.
It is preferable to apply pressure and heat for smoothing.

The polyolefin resin-coated paper is formed by a melt extrusion coating method of casting a heated and melted polyolefin resin on a running base paper, or by coating a polyolefin resin emulsion.
It is manufactured by a drying emulsion coating method or the like. or,
The resin coating layer can be provided on one or both surfaces of the base paper, but is preferably provided on both surfaces from the viewpoint of preventing curling. Further, when producing a polyolefin resin-coated paper, it is preferable to perform a surface activation treatment such as a corona discharge treatment, a flame treatment and an anchor layer coating on the base paper in order to improve the adhesion between the polyolefin resin and the base paper. .

The polyolefin resin constituting the resin coating layer includes ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene,
-A homopolymer or copolymer such as heptene, 1-octene and 1-nonene can be used. The resin coating layer may contain various additives such as a lubricant, an antioxidant, an ultraviolet absorber, a plasticizer, an adhesive and a curing agent, in addition to the above-mentioned polyolefin resin, pigment and dye.

The structure of the resin coating layer may be either a single layer or a multi-layer, and each layer of the multi-layer may have a different composition or the same composition. When forming a multi-layer resin coating layer, two or more layers may be applied at a time or one layer at a time. Further, the thickness of the resin coating layer is preferably at least 10 μm in order to obtain good smoothness.

Improving the adhesion between the support and the ink receiving layer;
For the purpose of improving the surface reflection characteristics of the ink jet recording sheet, an intermediate layer may be provided between the support and the ink receiving layer. In such an intermediate layer, in addition to the above pigments and dyes, a water-soluble resin, a resin emulsion, a surfactant, an ultraviolet absorber, an antioxidant, an antifoaming agent, a leveling agent, a preservative, a condensing agent, A regulator and the like can be blended.

The intermediate layer is formed on a support by a general coating method such as a rod method, a wire bar method, a slide hopper method, a curtain method, an extrusion die method, an air knife method, a roll method, and a blade method. Coated on top.

As in the third aspect, various pigments and resins are used in the ink receiving layer together with other additives to enhance the ink receptivity.

The ink receiving layer is provided on at least one side of the support, but may be provided on both sides of the support for the purpose of performing double-sided printing and preventing curling. The ink receiving layer may be a single layer or a multilayer of two or more layers. In the case of a multilayer, the layers may have different compositions or may have the same composition. Further, in the case of forming a multilayer, two or more layers may be applied at a time or one layer at a time.

The dry coating amount of the ink receiving layer is 1 to 30 g.
/ M ² . When the dry coating amount of the ink receiving layer is less than 1 g / m ² , the ink receptivity is poor, so that the ink overflows after printing, and contamination due to color mixing or rubbing of the image is likely to occur. If it exceeds 30 g / m ² , the image resolution may decrease due to sinking of the ink,
Problems such as curling of the recording sheet occur.

The ink receiving layer or the intermediate layer is formed by a rod system, a wire bar system, a slide hopper system,
Coating is performed on the support by a general coating method such as a curtain method, an extrusion die method, an air knife method, a roll method, and a blade method.

A backing layer is provided on the side of the support opposite to the ink-receiving layer for the purpose of preventing curling of the support, preventing blocking, enhancing conductivity, and imparting pencil or ballpoint pen brushability. Is also good. In such a backing layer, a pigment, a water-soluble resin, a resin emulsion, a surfactant, a conductive agent, a curing agent, an antifoaming agent, a leveling agent, a preservative, a viscosity stabilizer, a pH regulator, and the like may be blended. Can be.

Such a backing layer is supported by a general coating method such as a rod method, a wire bar method, a slide hopper method, a curtain method, an extrusion die method, an air knife method, a roll method, and a blade method. Coated on the body.

In the fourth aspect, a polyolefin resin-coated paper in which L, a, and b according to the CIELAB classification of the surface of the polyolefin resin coating layer for coating the ink receiving layer are within a specific range is used as a support. An ink jet recording sheet having visually excellent whiteness, high image sharpness, and good color reproducibility can be obtained.

Next, the fifth aspect will be described. In order to make the values of L, a, and b on the surface of the ink receiving layer fall within the range of the present invention, it is achieved by adding various coloring agents to the ink receiving layer.

Examples of the coloring agent to be added include a coloring pigment, a coloring dye, a fluorescent dye, and the like. The amount of the coloring agent may be appropriately changed according to the amount of the support or the coating amount of the ink receiving layer. it can.

As the support, those mentioned in the third aspect can be used. The ink receiving layer is mainly composed of non-spherical cationic colloidal silica and a binder in order to enhance ink absorption and improve dot reproducibility and water resistance.

The non-spherical cationic colloidal silica is obtained by coating the surface of a non-spherical colloidal silica with a hydrated metal oxide and cation-modifying the same. The non-spherical shape in the present invention means that it is not substantially spherical, and needle-like or fibrous ones are preferably used. The size is preferably such that the major axis has a size of about several nm to 500 nm.

As the hydrated metal oxide for cationically modifying the non-spherical colloidal silica, hydrated aluminum oxide, hydrated zirconium hydroxide, hydrated tin oxide and the like are used.
Particularly, those modified by cation with hydrous aluminum hydroxide are preferably used. As a method of cation modification, US Pat. No. 3,007,878, JP-B-47-2695
No. 9 and the like.

In the non-spherical cationic colloidal silica, the coating amount of the hydrated metal oxide as the cation modifier is 1 to 30 in terms of weight with respect to silica (in terms of SiO ₂ ).
% By weight is appropriate. If the coating amount of the cationic modifier is too small, the dot reproducibility and water resistance of the ink jet recording sheet are deteriorated, while if too large, the film of the ink receiving layer becomes brittle and easily cracks.
Particularly preferred is 2.5 to 25% by weight, most preferably 5 to 20% by weight. The dispersion of the non-spherical cationic colloidal silica may contain an acid component such as acetic acid, citric acid, sulfuric acid, and phosphoric acid for the purpose of a colloid stabilizer. Specific examples of such non-spherical cationic colloidal silica include ST-special modified series manufactured by Nissan Chemical Industries, Ltd.

The binders used in the ink receiving layer include the following polymers. Lime-treated gelatin, acid-treated gelatin, enzyme-treated gelatin, gelatin derivatives such as phthalic acid, maleic acid, various gelatins such as gelatin reacted with an anhydride of a dibasic acid such as fumaric acid, polyvinyl alcohol of various saponification degrees, Carboxy-modified, cationic-modified and amphoteric polyvinyl alcohol or derivatives thereof, oxidized starch, cationized starch, starches such as etherified starch, carboxymethylcellulose, cellulose derivatives such as hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylpyridium halide, Sodium polyacrylate, methacrylic acid copolymer salt, polyethylene glycol, polypropylene glycol, polyvinyl ether, alkyl vinyl ether / maleic anhydride copolymer, styrene / maleic anhydride copolymer Are salts thereof, synthetic polymers such as polyethyleneimine, styrene-butadiene copolymer, conjugated diene copolymer latex such as methyl methacrylate / butadiene copolymer, polyvinyl acetate, vinyl acetate / maleic ester copolymer, Vinyl acetate polymer latex such as vinyl acetate / acrylate copolymer, ethylene / vinyl acetate copolymer, acrylate polymer, methacrylate polymer, ethylene / acrylate copolymer, styrene / acryl Acrylic polymers or copolymer latexes such as acid ester copolymers, vinylidene chloride copolymer latexes, or functional group-modified polymers of these various polymers with functional group-containing monomers such as carboxyl groups Water such as latex, melamine resin, urea resin and other thermosetting synthetic resin Adhesives and polymethylmethacrylate, polyurethane resin, unsaturated polyester resin,
Polymers such as synthetic resin adhesives such as vinyl chloride / vinyl acetate copolymers, polyvinyl butyral, and alkyd resins can be used alone or in combination.

The amount of these polymers used is 2 to 100 parts by weight based on 100 parts by weight of the solid content of the non-spherical cationic colloidal silica in consideration of the conflicting balance between dot reproducibility with respect to the water absorption of the ink and water resistance. Parts are suitable, but 5 to 30 parts by weight are particularly preferred.

The ink receiving layer may contain various surfactants for the purpose of improving the sharpness of an image. Such a surfactant 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 may be used in combination.

Preferred examples of the surfactant include anionic surfactants such as a long-chain alkyl benzene sulfonate, a long-chain, preferably branched alkyl sulfosuccinate, and a long-chain, preferably branched alkyl. Nonionic surfactants such as group-containing phenols and polyalkylene oxide ethers, and polyalkylene oxide ethers of long-chain alkyl alcohols; fluorinated interfaces described in JP-B-47-9303, U.S. Pat. No. 3,589,906 and the like. Activators and the like can be mentioned.

The addition amount of the surfactant is preferably from 0.1 to 7% by weight, more preferably from 0.5 to 3% by weight, based on the dry solid weight of the ink receiving layer.

The ink receiving layer may contain various additives in addition to the non-spherical cationic colloidal silica, the binder and the surfactant.

For example, pigments such as silica, colloidal silica, magnesium carbonate, calcium carbonate, titanium oxide and zinc oxide, γ-aminopropyltriethoxysilane, N
A silane coupling agent such as -β (aminoethyl) γ-aminopropyltrimethoxysilane, a polymer hardener, an active halogen compound, a vinyl sulfone compound,
Aziridine compounds, epoxy compounds, acryloyl compounds, hardening agents such as isocyanate compounds, as preservatives,
P-hydroxybenzoic acid ester compounds, benzisothiazolone compounds, isothiazolone compounds described in JP-A-1-102551, JP-A-63-20425, and the like.
No. 1, JP-A-1-26637, etc., as a UV absorber, a benzotriazole compound having a hydroxy-di-alkylphenyl group at the 2-position, an antioxidant, etc. , JP
JP-A-105245, polyhindered phenol compounds and the like, as a pencil writing agent, organic or inorganic particles such as starch granules, barium sulfate, silica, etc., having a particle size of 0.2 to 5 μm; The organopolysiloxane compound described in the above, as a pH adjuster, various additives such as caustic soda, sodium carbonate, sulfuric acid, hydrochloric acid, phosphoric acid, citric acid, etc., octyl alcohol, silicon-based antifoaming agent may be appropriately combined and contained. it can.

The dry coating amount of the ink receiving layer was 1 to 30 g.
/ M ² . Coating amount of ink receiving layer is 1
If it is less than g / m ² , the ink receptivity is inferior, so that the ink after printing overflows from the ink receiving layer, and the image is likely to be contaminated by color mixing or rubbing. If it exceeds 30 g / m ² , problems such as lowering of image resolution due to sinking of ink and curling of the recording sheet will occur.

The coating method of the ink receiving layer coating liquid includes a rod method, a wire bar method, a slide hopper method,
General coating methods such as a curtain method, an extrusion die method, an air knife method, a roll method, and a blade method are used.

As in the third aspect, the ink receiving layer may be a single layer or a multilayer of two or more layers. In the case of a multilayer, each layer can have a different composition or the same composition. In the case of forming a multilayer, two or more layers may be applied at a time or one layer at a time.

The ink receiving layer is provided on at least one side of the support, but may be provided on both sides of the support for the purpose of performing double-sided printing or preventing curling.

In the fifth aspect, an ink receiving layer mainly composed of non-spherical colloidal silica and a binder is provided, and the values of the lightness index L and the perceived chromaticity indexes a and b of the surface of the ink receiving layer are set within the characteristic range. By doing so, an ink jet recording sheet having visually excellent whiteness, high image sharpness, good color reproducibility, and excellent dot reproducibility and water resistance can be obtained.

[0114]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples, but the contents of the present invention are not limited to the examples. In addition, "parts" means parts by weight.

Example 1 A resin composition consisting of 85 parts by weight of low-density polyethylene and 15 parts by weight of titanium dioxide was coated on the surface of a base paper of LBKP having a basis weight of 100 g / m ² at 25 g / m ² . A resin composition comprising 50 parts by weight of high-density polyethylene and 50 parts by weight of low-density polyethylene was applied at 20 g / m ² to prepare a resin-coated paper. After the surface of the resin-coated paper is subjected to corona treatment, the weight of the ink receiving layer coating liquid having the following composition after drying is 8 g.
/ M ² by an extrusion method. Immediately after cooling and setting for 10 seconds, it is passed through a drying zone where the temperature is gradually increased while controlling the temperature and humidity, and the temperature and humidity of the drying zone are controlled so that the surface wet bulb temperature becomes 20 ° C or less, and ink jet recording A sheet was prepared. (Ink receiving layer composition 1) Low molecular weight gelatin (molecular weight 95,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.3 part

Example 2 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied to the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 2) Low molecular weight gelatin (molecular weight 70,000) 30 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 70 parts Mucochloric acid 0.2 part

Example 3 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied to the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 3) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.05 part

Example 4 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied to the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 4) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 100,000, degree of etherification 1.0%) 50 parts Mucochloric acid 0.5 part

Example 5 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied to the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 5) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 100,000, degree of etherification 1.0%) 50 parts Mucochloric acid 0.3 part

Example 6 An ink receiving layer coating solution having the following composition was applied in the same manner as in Example 1 except that the resin-coated paper used as the support was changed to a polyethylene terephthalate film having a thickness of 100 μm. Thus, an inkjet image receiving sheet was produced. (Ink receiving layer formulation 6) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.3 part

Example 7 In the same manner as in Example 1, the ink receiving layer coating solution having the following composition was applied on the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 7) Low molecular weight gelatin (molecular weight 120,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 80 parts Mucochloric acid 0.3 part

Example 8 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied onto the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 8) Low molecular weight gelatin (molecular weight 70,000) 20 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 80 parts Mucochloric acid 0.1 part

Example 9 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied on the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 9) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.04 part

Example 10 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied on the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 10) Gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.6 part

Example 11 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied on the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer formulation 11) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 120,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.3 part

Example 12 In the same manner as in Example 1, an ink receiving layer coating solution having the following composition was applied on the support of Example 1 to prepare an ink jet recording sheet. (Ink receiving layer composition 12) Low molecular weight gelatin (molecular weight 70,000) 50 parts Carboxymethyl cellulose (molecular weight 80,000, degree of etherification 0.8%) 50 parts Mucochloric acid 0.3 part Each sheet obtained as described above About HEWLE
Images were recorded using a Desk Writer C inkjet printer manufactured by TT PACKARD, and the following quality tests were performed. The evaluation results are shown in Table 1.

<Image Area Unevenness> The image area was visually observed to determine the presence or absence of unevenness particularly in the supercolored area.

<Bleeding> A single color or a multicolor was continuously recorded, and it was visually determined whether or not adjacent printed portions bleed out to each other or to one side.

<Character Drawability> It was visually determined whether or not the drawability of the recorded characters was high and clear.

<Applicability> It was determined whether the application of the ink receiving layer coating liquid was difficult due to its high viscosity.

The evaluation criteria are as follows. ◎: Excellent without any problems, ：: Excellent, Δ: Usable, ×: Poor.

[Table 1]

As is clear from the results in Table 1, Examples 1 to 6
In the ink jet recording sheet of No. 5, good results were obtained in any of the evaluation items. On the other hand, when the molecular weight of gelatin is high as in Example 7, the compatibility with carboxymethylcellulose is poor, so that the ink receptivity is not uniform, the image area is uneven, and the character drawing performance is poor. Example 8
When the content of low molecular weight gelatin is small as in
In the case where the content of mucochloric acid is large as in the above, the ink receiving layer is inferior in ink receptivity, so that the bleeding of the image area is remarkable. When the content of mucochloric acid is small as in Example 9, the curing of the coating of the receiving layer is insufficient, so that the receiving layer starts to flow after printing and the character drawing property is poor. When the molecular weight of carboxymethylcellulose is high as in Example 11 or when the degree of etherification of carboxymethylcellulose is high as in Example 12, the viscosity of the coating liquid increases and the coatability deteriorates.

As described above, it is possible to obtain an ink jet recording sheet having excellent image clarity, resolution, uniformity, and ink adsorbability.

Example 13 Basis weight 1 made of LBKP (hardwood bleached kraft pulp)
A resin composition comprising 85 parts by weight of low-density polyethylene and 15 parts by weight of titanium dioxide was coated on the surface of a base paper of 00 g / m ^2.
6 g / m ^{2 was} applied, and a resin composition comprising 60 parts by weight of high-density polyethylene and 40 parts by weight of low-density polyethylene was applied on the back surface at 16 g / m ² to prepare a resin-coated paper. After the surface of the resin-coated paper is subjected to corona treatment, a polymer compound (average molecular weight of 12) is obtained by reacting an ethylene oxide adduct of dipropylene glycol with an adipic acid monoester.
(10,000) An ink receiving layer coating liquid having a solid content of 10%, prepared by adding 80 parts by weight of polyvinyl alcohol to 20 parts by weight, is applied by a bar coater so as to have a dry weight of 10 g / m ² , dried, and inkjet-recorded. A sheet was prepared.

Example 14 In the same manner as in Example 13 on the support of Example 13, 80 parts by weight of polyvinyl alcohol was added to 20 parts by weight of a polymer compound (molecular weight: 70,000) obtained from polyethylene glycol and dimethyl terephthalate. The ink receiving layer coating liquid having a solid content of 10% prepared as described above was applied to prepare an ink jet recording sheet.

Example 15 A polymer compound (average molecular weight: 170,000) obtained from the ethylene oxide adduct of polytetramethylene glycol and pyromellitic dianhydride in the same manner as in Example 13 on the support of Example 13 (20 weight%) In the part, polyvinyl alcohol 80
The ink receiving layer coating liquid having a solid content of 10% prepared by adding parts by weight was applied to prepare an ink jet recording sheet.

Example 16 In the same manner as in Example 13 on the support of Example 13, 20 parts by weight of a polymer compound (average molecular weight: 40,000) obtained from an ethylene oxide adduct of bisphenol A and succinic anhydride were added to polyvinyl alcohol. A 10% solids aqueous solution prepared by adding 80 parts by weight was applied to prepare an ink jet recording sheet.

Example 17 On the support of Example 13, 20 parts by weight of a polymer compound (average molecular weight: 320,000) obtained from polyethylene glycol and 4,4'-methylenebis- (phenylisocyanate) in the same manner as in Example 13 Then, a 10% solids aqueous solution prepared by adding 80 parts by weight of polyvinyl alcohol was applied thereto to prepare an ink jet recording sheet.

Example 18 The procedure of Example 1 was carried out on the support of Example 13 in the same manner as in Example 13.
To 3 parts by weight of the same polymer compound as used in No. 3 was added 97 parts by weight of polyvinyl alcohol to apply an ink receiving layer coating liquid having a solid content of 10% to prepare an ink jet recording sheet.

Example 19 The procedure of Example 13 was carried out on the support of Example 13 in the same manner as in Example 13.
A 10% aqueous solution of the same polymer compound as used in No. 3 was applied to prepare an ink jet recording sheet.

Example 20 The procedure of Example 13 was carried out on the support of Example 13 in the same manner as in Example 13.
To 1 part by weight of the same polymer compound as used in No. 3 was added 99 parts by weight of polyvinyl alcohol to apply a 10% solids ink-receiving layer coating solution to prepare an ink jet recording sheet.

Example 21 The same coating liquid as used in Example 13 was applied onto the support of Example 13 so that the weight after drying was 1 g / m ² , to produce an ink jet recording sheet.

Example 22 The same coating liquid as used in Example 13 was applied on the support of Example 13 so that the weight after drying was 30 g / m ² , to produce an ink jet recording sheet.

Example 23 An ink jet recording sheet was prepared by applying the same coating liquid as used in Example 13 on the support of Example 13 so that the weight after drying was 0.5 g / m ² .

Example 24 The same coating liquid as used in Example 13 was applied on the support of Example 13 so that the weight after drying was 40 g / m ² , to produce an ink jet recording sheet.

Example 25 An ink jet recording sheet was prepared in the same manner as in Example 13, except that the resin-coated paper used as the support was changed to a polyethylene terephthalate film having a thickness of 100 μm.

Example 26 A 10% aqueous solution of polyvinyl alcohol was applied on the support of Example 13 in the same manner as in Example 13 to prepare an ink jet recording sheet.

Example 27 An ink jet recording sheet was prepared in the same manner as in Example 26 except that the resin-coated paper used as the support was changed to a polyethylene terephthalate film having a thickness of 100 μm.

Each of the ink jet recording sheets obtained as described above was subjected to HEWLETT PACKARD.
Images were recorded using a Desk Writer 550C color inkjet printer manufactured by the company, and the following quality tests were performed. The evaluation results are shown in Table 2.

<Clearness of Image> A single color or a multi-color was continuously recorded, and it was visually determined whether or not adjacent print portions bleed out to each other or to one side.

<Dryability> The solid color printing portion immediately after printing was observed, and the dried state of the ink was visually determined.

<Applicability> The surface of the ink receiving layer was observed, and the state of bar streaks and uneven gloss was visually determined. The evaluation criteria are as follows. ◎: very good, ：: excellent, Δ: not hindered in use, ×: defective and cannot be used.

[Table 2]

As is clear from the results in Table 2, Examples 13 to
Good results were obtained for all the evaluation items of the 25 inkjet recording sheets.

On the other hand, when no specific polymer compound was used as in Examples 26 and 27, the ink absorption and drying were insufficient, and clear images could not be obtained.

As described above, it is possible to obtain an ink jet recording sheet with a clear image and excellent ink drying properties.

Example 28 The coating liquid of the ink receiving layer having the following composition was dried on the surface of a high-quality paper made of 70% LBKP and 30% NBKP (hardwood bleached kraft pulp) having a basis weight of 100 g / m ² using an air knife coater. Coating was performed so that the coating amount was 10 g / m ² , and the coating was dried to prepare an ink jet recording sheet.

<Ink Receiving Layer Coating Liquid Formulation 1> Silica (Carplex FPS-2 ^™ , Shionogi & Co., Ltd.) 100 parts Colloidal silica (Snowtex C ^™ , Nissan Chemical) 20 parts Polyvinyl alcohol (Kuraray, PVA110) 30 parts Dye fixing agent (BASF Japan, Catiofast PL ^™ ) 5 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Japan 1 part Kaycoll BUL ^™ manufactured by Soda, 0.01 part surfactant (trax K-40 ^™ manufactured by NOF Corporation)

Example 29 The coating weight of the ink-receiving layer of Example 28 was dried to 10 g / m ² on the surface of a coated paper having a basis weight of 84.9 g / m ² using an air knife coater. It was coated and dried as described above to produce an ink jet recording sheet.

Example 30 A 100 μm-thick white polyethylene terephthalate film was coated on a surface thereof with a wire bar coater so as to have a dry coating amount of 8 g / m ² with the following ink-receiving layer coating solution.
After drying, an ink jet recording sheet was prepared.

<Ink Receiving Layer Coating Liquid Formulation 2> Colloidal Silica (Snowtex C ^™ , manufactured by Nissan Chemical) 100 parts Carboxymethylcellulose (Daiichi Kogyo Seiyaku, Cellogen BSH-12) 100 parts Blue dye (manufactured by BASF Japan, blue) 16L ^™ ) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL) 0.5 parts Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0.02 parts

Example 31 The coating liquid of the ink receiving layer of Example 30 was dried on a surface of a polyethylene laminated paper having a basis weight of 142.5 g / m ² using a wire bar coater to a dry coating amount of 8 g / m ² . It was coated and dried as described above to produce an ink jet recording sheet.

Example 32 An ink jet recording sheet was prepared in the same manner as in Example 28, except that the coating composition for the ink receiving layer was changed to the following composition. <Ink-receiving layer coating liquid formulation 3> Silica (Carplex FPS-2 ^™ , Shionogi & Co., Ltd.) 100 parts Colloidal silica (Nissan Chemical, Snowtex C ^™ ) 20 parts Polyvinyl alcohol (Kuraray, PVA110) 30 parts Dye 5 parts of fixing agent (manufactured by BASF Japan, Kachiofast PL ^™ ) 5 parts of surfactant (manufactured by NOF CORPORATION, TRAX K-40 ^™ ) 0.01 part

Example 33 An ink jet recording sheet was prepared in the same manner as in Example 28 except that the coating composition for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 4> Silica (manufactured by Shionogi & Co., Inc., Carplex FPS-2 ^™ ) 100 parts Colloidal silica (manufactured by Nissan Chemical Industries, Snowtex C ^™ ) 20 parts Polyvinyl alcohol (manufactured by Kuraray, PVA110) 30 parts Dye Fixing agent (BASF Japan, Kachiofast PL ^™ ) 5 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fats, Trucks) K-40 ^™ ) 0.01 parts

Example 34 An ink jet recording sheet was prepared in the same manner as in Example 28 except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink receiving layer coating solution formulation 5> Silica (Carplex FPS-2 ^™ , Shionogi & Co., Ltd.) 100 parts Colloidal silica (Nissan Chemical, Snowtex C ^™ ) 20 parts Polyvinyl alcohol (Kuraray, PVA110) 30 parts Dye Fixing agent (BASF Japan, Kachiofast PL ^™ ) 5 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.01 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (TRAX K-40 ^™ manufactured by NOF 0.01 parts)

Example 35 An ink jet recording sheet was prepared in the same manner as in Example 28 except that the coating composition for the ink receiving layer was changed to the following composition. <Ink receiving layer coating solution formulation 6> Silica (Carplex FPS-2 ^™ , Shionogi & Co., Ltd.) 100 parts Colloidal silica (Nissan Chemical, Snowtex C ^™ ) 20 parts Polyvinyl alcohol (Kuraray, PVA110) 30 parts Dye Fixing agent (BASF Japan, Kachiofast PL ^™ ) 5 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Yushi, Trax K-40 ^™ ) 0.01 parts

Example 36 An ink jet recording sheet was prepared in the same manner as in Example 28 except that the coating composition for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 7> Silica (manufactured by Shionogi & Co., Carplex FPS-2 ^™ ) 100 parts Colloidal silica (manufactured by Nissan Chemical Industries, Snowtex C ^™ ) 20 parts Polyvinyl alcohol (manufactured by Kuraray, PVA110) 30 parts Dye Fixing agent (BASF Japan, Kachiofast PL ^™ ) 5 parts Blue dye (BASF Japan, Blue 16L) 0.01 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (TRAX K-40 ^™ manufactured by NOF 0.01 parts)

The values of the lightness index L and the perceived chromaticity indexes a and b of the ink jet recording sheet obtained as described above were measured with a Minolta colorimeter CR-100, and are shown together with the visual evaluation results in Table 1. Indicated.

[Table 3]

As is clear from the results in Table 3, Examples 28 to
The No. 31 ink jet recording sheet had visually excellent whiteness and good color reproducibility of the image.

On the other hand, in the ink jet recording sheet of Example 32, since the blue dye, the red dye and the fluorescent dye were not added, the value of L decreased, the gray color became strong, and the yellow color became strong. In the ink jet recording sheet of Example 33, since the red dye was not added, the value of a decreased and the green color became strong. In the ink jet recording sheet of Example 34, since a large amount of the red dye was added, the value of a increased and the reddish color became strong. In the ink jet recording sheet of Example 35, since the blue dye was not added, the value of b increased and the yellow color became strong. In the ink jet recording sheet of Example 36, since a large amount of the blue dye was added, the value of b was lowered and the bluish color became strong.

As described above, when the values of the lightness index L and the perceived chromaticity indexes a and b on the surface of the ink receiving layer are in specific ranges, the ink receiving layer has visually excellent whiteness and sharpness of the image. And an ink jet recording sheet having high color reproducibility can be obtained.

Example 37 Using a Fourdrinier paper machine, a base paper having the following composition and a basis weight of 100 g / m ² was prepared. <Base paper composition 1> 100 parts of LBKP Cationized starch (CATO 302 ^™ manufactured by Oji National) 10 parts Polyacrylamide (manufactured by Himo, Himoloc KL-86 ^™ ) 0.2 parts Alkyl ketene dimer (Dick Hercules, Harcon 601 ^™) 0.5) Polyamide epichlorohydrin resin (manufactured by Dick Hercules, Caimen 2064 ^™ ) 0.5 part Blue dye (Nippon Kayaku, Blue B) 0.5 part Red dye (Nippon Kayaku, Red B) 5 copies

Next, using a size press, the base paper was impregnated with an impregnating solution having the following composition so that the dry weight was 2.0 g / m ² . <Impregnating liquid formulation 1> Polyvinyl alcohol (Kuraray, PVA110) 2 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 0.2 parts Conductive agent (Sanyo Chemical Industries, Chemistat 6120 ^™ ) 1 part

After performing a corona discharge treatment on the back surface of the base paper, a thickness of 20 μm was applied by a melt extrusion coating method.
A backside resin coating layer having the following composition was provided. <Backside resin coating layer composition 1> Low density polyethylene (density 0.92 g / cm ³ ) 30 parts High density polyethylene (density 0.96 g / cm ³ ) 70 parts

Further, after the surface of the base paper was subjected to a corona discharge treatment, a surface resin coating layer having the following composition was provided by a melt extrusion coating method so as to have a thickness of 20 μm, thereby producing a support. <Surface resin coating layer composition 1> Low density polyethylene (density 0.92 g / cm ³ ) 74 parts High density polyethylene (density 0.97 g / cm ³ ) 15 parts White pigment (anatase type titanium dioxide) 10 parts Blue pigment (Ultra blue) 0.5 parts zinc stearate 0.5 parts

After subjecting the surface of the support to corona discharge treatment, an intermediate layer coating solution having the following composition was applied using an air knife coater so that the dry coating amount was 0.1 g / m ^2. Worked and dried. <Intermediate layer coating liquid formulation 1> Gelatin 100 parts Hardener (Nagase Kasei Kogyo, Denacol EX-810 ^™ ) 1 part Surfactant (Nippon Oil & Fats, Rapisol B-30 ^™ ) 0.05 part

After subjecting the back surface of the support to corona discharge treatment, a back coat layer coating solution having the following composition was applied using a wire bar coater so that the dry coating amount was 5 g / m ^2. Coated and dried. <Coating composition of back coating layer 1> Gelatin 100 parts Silica (Carplex FPS-2 ^™ manufactured by Shionogi & Co., Ltd.) 10 parts Hardening agent (Danacol EX-810 ^™ manufactured by Nagase Kasei Kogyo) 1 part Conductive agent (Sanyo Chemical Industries, Ltd.) Chemistat 6120 ^™ ) 1 part Surfactant (Nippon Oil & Fats Co., Ltd., Lapisol B-30 ^™ ) 0.05 part

Further, an ink receiving layer coating liquid having the following composition was applied on the intermediate layer using an air knife coater so that the dry coating amount was 10 g / m ² , and dried to form an ink jet recording sheet. Was prepared. <Ink receiving layer coating liquid composition 8> Silica (Carplex FPS-2 ^™ manufactured by Shionogi & Co., Ltd.) 100 parts Colloidal silica (Nissan Chemical; Snowtex C ^™ ) 20 parts Polyvinyl alcohol (Kuraray manufactured, PVA110) 30 parts Dye 5 parts of fixing agent (manufactured by BASF Japan, Kachiofast PL ^™ ) 5 parts of surfactant (manufactured by NOF CORPORATION, TRAX K-40 ^™ ) 0.01 part

Example 38 A surface resin coating layer having the following composition was provided on the surface of the base paper of Example 37 using an air knife coater so that the dry weight was 20 g / m ² . <Surface resin coating layer composition 2> Polyethylene emulsion (manufactured by Iron and Steel Chemical, Seixen-A ^™ ) 100 parts White pigment (barium sulfate) 50 parts Blue dye (Nippon Kayaku, Blue B) 0.1 part Red dye (Nippon Kagaku) Pharmaceutical, Red B) 0.1 part

A backside resin coating layer having the following composition was provided on the backside using an air knife coater so that the dry weight was 20 g / m ² , to produce a support. <Backside resin coating layer composition 2> 100 parts of polyethylene emulsion (manufactured by Iron and Steel Chemical Co., Ltd., Seixen-A ^™ )

Then, an ink-receiving layer having the following composition was applied to the surface of the support using a wire bar coater so that the dry coating amount was 8 g / m ² , followed by drying. Was prepared. <Ink receiving layer coating liquid composition 9> Gelatin 10 parts Polyvinyl alcohol (Kuraray, PVA110) 30 parts Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0.01 part

Example 39 Example 37 was carried out except that the composition of the impregnating liquid in Example 37 was changed to the following composition.
In the same manner as in the above, an ink jet recording sheet was produced. <Impregnating liquid formulation 2> Polyvinyl alcohol (Kuraray, PVA110) 2 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 0.05 parts Conductive agent (Sanyo Chemical Industries, Chemistat 6120 ^™ ) 1 part

Example 40 An ink jet recording sheet was produced in the same manner as in Example 37 except that the composition of the base paper in Example 37 was changed to the following composition. <Base paper composition 2> LBKP 100 parts Cationized starch (CATO 302 ^™ , manufactured by Oji National) 10 parts Polyacrylamide (Himo, Himoloc KL-86 ^™ ) 0.2 parts Alkyl ketene dimer (Dick Hercules, Harcon 601 ^™) 0.5) Polyamide epichlorohydrin resin (manufactured by Dick Hercules, Caimen 2064 ^™ ) 0.5 part Blue dye (Nippon Kayaku, Blue B) 0.5 part Red dye (Nippon Kayaku, Red B) 2 copies

Example 41 An ink jet recording sheet was produced in the same manner as in Example 37 except that the composition of the base paper in Example 37 was changed to the following composition. <Base paper mix 3> LBKP 100 parts Cationized starch (manufactured by Oji National, CATO ^™ 302) 10 parts Polyacrylamide (manufactured by Himo, Himoloc KL-86 ^™ ) 0.2 parts Alkyl ketene dimer (manufactured by Dick Hercules, Harcon 601 ^™) 0.5) Polyamide epichlorohydrin resin (manufactured by Dick Hercules, Caimen 2064 ^™ ) 0.5 part Blue dye (Nippon Kayaku, Blue B) 0.2 part Red dye (Nippon Kayaku, Red B) 5 copies

Example 42 An ink jet recording sheet was prepared in the same manner as in Example 37 except that the composition of the surface resin coating layer was changed to the following composition. <Surface resin coating layer composition 3> Low density polyethylene (density 0.92 g / cm ³ ) 70 parts High density polyethylene (density 0.97 g / cm ³ ) 15 parts White pigment (anatase type titanium dioxide) 5 parts Blue pigment (Ultra blue) 0.5 parts zinc stearate 0.5 parts

Example 43 An ink jet recording sheet was produced in the same manner as in Example 37 except that the composition of the base paper was changed to the following composition. <Base paper composition 4> LBKP 100 parts Cationized starch (CATO 302 ^™ , manufactured by Oji National) 10 parts Polyacrylamide (Himo, Hymoloc KL-86 ^™ ) 0.2 parts Alkyl ketene dimer (Dick Hercules, Harcon 601 ^™) 0.5 part polyamide epichlorohydrin resin (manufactured by Dick Hercules, Caimen 2064 ^™ ) 0.5 part Blue dye (Nippon Kayaku, Blue B) 0.5 part

Example 44 An ink jet recording sheet was produced in the same manner as in Example 37 except that the composition of the base paper was changed to the following composition. <Base paper composition 5> 100 parts of LBKP Cationized starch (CATO 302 ^™ manufactured by Oji National) 10 parts Polyacrylamide (manufactured by Himo, Himoloc KL-86 ^™ ) 0.2 parts Alkyl ketene dimer (manufactured by Dick Hercules, Harcon 601 ^™) 0.5) Polyamide epichlorohydrin resin (manufactured by Dick Hercules, Caimen 2064 ^™ ) 0.5 part Blue dye (Nippon Kayaku, Blue B) 0.5 part Red dye (Nippon Kayaku, Red B) 0 copies

Example 45 An ink jet recording sheet was prepared in the same manner as in Example 37 except that the composition of the surface resin coating layer was changed to the following composition. <Surface resin coating layer composition 4> Low density polyethylene (density 0.92 g / cm ³ ) 70 parts High density polyethylene (density 0.97 g / cm ³ ) 15 parts White pigment (anatase type titanium dioxide) 10 parts Stearic acid 0.5 parts of zinc

Example 46 An ink jet recording sheet was produced in the same manner as in Example 37 except that the composition of the surface resin coating layer was changed to the following composition. <Surface resin coating layer composition 5> Low density polyethylene (density 0.92 g / cm ³ ) 70 parts High density polyethylene (density 0.97 g / cm ³ ) 15 parts White pigment (anatase type titanium dioxide) 10 parts Blue pigment (Gunblue) 1 part Zinc stearate 0.5 part

The values of L, a, and b of the surface of the support obtained as described above, which receives the ink receiving layer, were measured with a color difference meter CR-100 manufactured by Minolta, and the ink jet image was obtained by coating the ink receiving layer. Table 4 shows the results together with the visual evaluation results of the sheets.

[Table 4]

As is clear from the results in Table 4, the ink jet recording sheets of Examples 37 to 41 according to the present invention had visually excellent whiteness and good color reproducibility of images. On the other hand, in the ink jet recording sheet of Example 42, since the amount of the white pigment added to the surface resin coating layer of the support was small, the values of L and b were reduced, and the grayish and yellowish colors became strong. In the ink jet recording sheet of Example 43, since the red dye was not added to the base paper, the value of a was lowered and the green color became strong. In the ink jet recording sheet of Example 44, since a large amount of the red dye was added to the base paper, the value of a increased and the reddish color became strong. In the ink jet recording sheet of Example 45, since the blue pigment was not added to the surface resin coating layer, the value of b increased and the yellow color became strong. In the ink jet recording sheet of Example 46, since a large amount of the blue pigment was added to the surface resin coating layer, the value of b was reduced and the bluish color became strong.

As described above, an ink jet recording sheet having visually excellent whiteness, high image sharpness, and good color reproducibility can be obtained.

Example 47 A basis weight of 100 g consisting of 70% LBKP and 30% NBKP
/ M ² of high-quality paper, the dry coating amount of the ink receiving layer coating liquid having the following formulation was 10 g using an air knife coater.
/ M ² and dried to produce an ink jet recording sheet.

The non-spherical cationic colloidal silica in the following ink-receiving layer coating composition was cationized with hydrous aluminum hydroxide, and the amount of the silica was changed to silica (SiO ₂
It is 11.7% by weight based on (converted). <Ink receiving layer coating liquid formulation 10> Non-spherical cationic colloidal silica (Nissan Chemical, Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0 .01 copies

Example 48 The coating liquid of the ink receiving layer of Example 47 was dried on the surface of a coated paper having a basis weight of 84.9 g / m ² using an air knife coater to a dry coating weight of 10 g / m ² . It was coated and dried as described above to produce an ink jet recording sheet.

Example 49 Using a wire bar coater on the surface of a 100 μm-thick white polyethylene terephthalate film, Example 4 was used.
The ink receiving layer coating liquid of No. 7 was applied so as to have a dry coating amount of 20 g / m ² and dried to prepare an ink jet recording sheet.

Example 50 Using a wire bar coater, the coating liquid of the ink receiving layer of Example 47 was applied to a surface of a polyethylene laminated paper having a basis weight of 142.5 g / m ² to a dry coating amount of 20 g / m ² . Coating and drying were performed to prepare an ink jet recording sheet.

Example 51 An ink jet recording sheet was prepared in the same manner as in Example 47 except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink-receiving layer coating liquid formulation 11> Non-spherical cationic colloidal silica (Nissan Chemical Co., Ltd., Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Surfactant (Nippon Oil & Fat Co., Ltd.) , Trax K-40 ^™ ) 0.01 parts

Example 52 An ink jet recording sheet was prepared in the same manner as in Example 47, except that the coating composition for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 11> Non-spherical cationic colloidal silica (Nissan Chemical, Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Fluorescent dye (manufactured by Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (manufactured by NOF CORPORATION, Trax K-40 ^™ ) 0.01 part

Example 53 An ink jet recording sheet was prepared in the same manner as in Example 47, except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 12> Non-spherical cationic colloidal silica (manufactured by Nissan Chemical Industries, Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (manufactured by Kuraray, PVA117) 30 parts Blue dye (manufactured by BASF Japan) Blue 16L) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.01 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0 .01 copies

Example 54 An ink jet recording sheet was prepared in the same manner as in Example 47 except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 13> Non-spherical cationic colloidal silica (Nissan Chemical, Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Red dye (Nippon Kayaku) , Red G) 0.002 parts Fluorescent dye (manufactured by Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (manufactured by NOF CORPORATION, Trax K-40 ^™ ) 0.01 part

Example 55 An ink jet recording sheet was prepared in the same manner as in Example 47, except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 14> Non-spherical cationic colloidal silica (manufactured by Nissan Chemical Industries, Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (manufactured by Kuraray, PVA117) 30 parts Blue dye (manufactured by BASF Japan) Blue 16L) 0.01 part Red dye (Nippon Kayaku, Red G) 0.002 part Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fat, Trax K-40 ^™ ) 0 .01 copies

Example 56 An ink jet recording sheet was prepared in the same manner as in Example 47, except that the coating composition for the ink receiving layer was changed to the following composition. <Ink receiving layer coating solution formulation 15> Non-spherical cationic colloidal silica (Nissan Chemical Co., Snowtex-UP-AK (1) ^™ ) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Blue dye (BASF Japan, Blue 16L) 0.002 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0 .01 copies

Example 57 An ink jet recording sheet was prepared in the same manner as in Example 47, except that the coating liquid for the ink receiving layer was changed to the following composition. <Ink receiving layer coating liquid formulation 16> Non-spherical cationic colloidal silica (Snowtex-AK ^™ manufactured by Nissan Chemical) 100 parts Polyvinyl alcohol (Kuraray, PVA117) 30 parts Blue dye (BASF Japan, Blue 16L) 0. 002 parts Red dye (Nippon Kayaku, Red G) 0.002 parts Fluorescent dye (Nippon Soda, Kaycoll BUL ^™ ) 1 part Surfactant (Nippon Oil & Fats, Trax K-40 ^™ ) 0.01 part

The values of the lightness index L and the perceived chromaticity indices a and b of the ink jet recording sheet obtained as described above were measured using a color difference meter CR-100 manufactured by Minolta.
Visual evaluation was also performed. Furthermore, HEWLETT PAC
Images were recorded using a KARD Desk Writer C inkjet printer, and the following quality tests were performed. Table 5 summarizes the above results.

<Dot Reproducibility> The ink jet recorded image was observed with a microscope, and the diameter and shape of the dot were visually determined. Here, the evaluation criteria were ○ for good and x for poor.

<Water resistance> 30 minutes after ink-jet recording of the image, the ink-jet recording sheet was pooled, immersed in water for 5 minutes, pulled up from the water and dried, and the residual state of the image and the bleeding state of the image were visually judged. . Here, the evaluation criteria were ○ for good and x for poor.

[Table 5]

As is clear from the results in Table 5, Examples 47 to
The 50 ink jet recording sheets had visually excellent whiteness, and also had good color reproducibility of images, dot reproducibility, and water resistance.

On the other hand, in the ink jet recording sheet of Example 51, since the blue dye, the red dye and the fluorescent dye were not added, the value of L was lowered, the gray color became strong, and the yellow color became strong. In the ink jet recording sheet of Example 52, since the red dye was not added, the value of a was lowered and the green color became strong. In the ink jet recording sheet of Example 53, since a large amount of the red dye was added, the value of a increased and the reddish color became strong. In the ink jet recording sheet of Example 54, since the blue dye was not added, the value of b increased and the yellow color became strong. In the ink jet recording sheet of Example 55, since a large amount of the blue dye was added, the value of b was lowered and the bluish color became strong. The non-spherical non-spherical colloidal silica used in the ink jet recording sheet of Example 56 was inferior in dot reproducibility and water resistance. The ink jet recording sheet of Example 57 was excellent in water resistance because cationized spherical colloidal silica was used, but resulted in poor dot reproducibility.

As described above, an ink jet recording sheet having visually excellent whiteness, high image sharpness, good color reproducibility and good water resistance can be obtained.

[0210]

Industrial Applicability Since an excellent image can be obtained by using the ink jet recording sheet of the present invention, the recording sheet can be used in various fields such as design image output.

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 5-158345 (32) Priority date June 29, 1993 (June 29, 1993) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 5-172991 (32) Priority date July 13, 1993 (July 13, 1993) (33) Country claiming priority Japan (JP) (72) Inventor Yasushi Yoshida Mine 3-4-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Paper Mills Co., Ltd. (56) References JP-A-62-162588 (JP, A) JP-A-62-271783 (JP, A) JP-A-2-150389 (JP, A) JP-A-1-115687 (JP, A) JP-A-1-206095 (JP, A) JP-A-60-219084 (JP, A) JP-A-2-274587 (JP, A) JP-A-61-188183 (JP, A) JP-A-61-32787 (JP, A) JP-A-61-181679 (JP, A) JP-A-62-8598 0 (JP, A) JP-A-59-222381 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00

Claims (11)

(57) [Claims] 1. An ink jet recording sheet provided with an ink receiving layer on at least one surface of a support, wherein the surface of the ink receiving layer is specified by JIS-Z8730 according to a measurement method specified by JIS-Z8722. An ink jet recording sheet having a lightness index L and a perceived chromaticity index a and b of -87 and -2 to +2 and -3 to +3, respectively. 2. In an ink jet recording sheet provided with an ink receiving layer on at least one surface of a support, the surface of the support on which the ink receiving layer is coated is JIS-Z872.
According to the measurement method specified in 2, the lightness index L of the surface and the perceived chromaticity index a and b specified in JIS-Z8730
Are 90 or more, -2 to +2, and -5 to 0, respectively. 3. The ink jet recording sheet according to claim 1, wherein said ink receiving layer component is mainly composed of non-spherical cationic colloidal silica and a binder. 4. An ink-receiving layer comprising a low-molecular-weight gelatin having a molecular weight of 100,000 or less in a solid content of 30% by weight or more of the total solid content constituting the ink-receiving layer, and mucochloric acid in a solid content of 0% based on the gelatin content. 4. The ink jet recording sheet according to claim 1, comprising a component consisting of carboxymethyl cellulose having a molecular weight of 100,000 or less and a degree of etherification of 1% or less. 5. The ink receiving layer is selected from the group consisting of a polyoxyalkylene glycol containing an ethylene oxide chain, a polycarboxylic acid, a polycarboxylic anhydride, a polycarboxylic lower alkyl ester and an organic polyisocyanate. 4. The ink jet recording sheet according to claim 1, wherein the ink jet recording sheet comprises a polymer compound obtained by reacting at least one compound obtained. 6. The method according to claim 1, wherein the polymer compound is 50,000 to 30.
The ink jet recording sheet according to claim 5, which has a molecular weight of 000. 7. The ink jet recording sheet according to claim 5, wherein the ink receiving layer contains a polymer compound of 2% by weight or more as a dry solid content. 8. The ink receiving layer has a dry coating amount of 1 to 30.
g / m ² in the ink-jet recording sheet according to claim 1, wherein. 9. The ink jet recording sheet according to claim 1, wherein the support is a polyolefin resin coated paper. 10. The ink jet recording sheet according to claim 1, wherein the support is a polyester film. 11. The ink jet recording sheet according to claim 9, wherein the polyolefin resin is a polyethylene resin.