JP2006224455A - Inkjet recording paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inkjet recording paper which makes prevention of a feeding flaw compatible with excellent ink absorbency and also satisfies various prescribed properties of the inkjet recording paper and which exhibits excellent characteristics even in the case when recycled pulp of wastepaper is used for a paper base material in particular. <P>SOLUTION: This inkjet recording paper has an undercoat layer and an ink accepting layer provided sequentially on at least one side of the paper base made from the pulp and it is subjected to calendering. The undercoat layer contains titanium dioxide, silica in the rate of 10-50 pts.mass to 100 pts.mass of the titanium dioxide, and an adhesive. The ink accepting layer contains silica of an average secondary particle diameter of 3-11 μm, the adhesive and a cationic ink fixative. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inkjet recording paper and printed matter using the same.

  The ink jet recording system that ejects water-based ink from fine nozzles toward the surface of the recording body and forms an image on the surface of the recording body has low noise during recording, easy formation of full-color images, and high-speed recording The printer is widely used in printers, facsimiles, plotters, form printing, and the like because of the fact that it is possible and the recording cost is lower than other printing apparatuses.

Various basic characteristics such as ink absorptivity, ink fixing property, color development property of the printing portion and storage stability thereof, whiteness of white paper portion and storage stability thereof are required for the recording medium in this ink jet recording system. .
In addition, ink jet recording papers corresponding to dye ink and pigment ink have been developed so far, but ink jet recording satisfying the above-mentioned basic characteristics regardless of whether dye ink or pigment ink is used. There is an increasing demand for paper.

  On the other hand, from the viewpoints of global environmental conservation and forest resource protection, efforts to increase the rate of utilization by increasing the recycling of used paper are also required.

More recently, in order to prevent displacement of the ink jet recording paper (paper blurring) when printing on ink jet recording paper as the printing speed increases, the image quality increases, and the printing apparatus becomes smaller, etc. The load applied by the paper feed roller for fixing the position of the inkjet recording paper is increasing.
For this reason, there is a tendency for printed matter to have a problem that a trace of conveyance by the paper feed roller (hereinafter referred to as a paper feed flaw) remains, and it is very important to prevent this paper flaw. It has become like this.
As a method for preventing paper feed damage caused by the paper feed roll, a method using polyvinyl alcohol having a high polymerization degree as an adhesive (Patent Document 1) has been proposed.
JP-A-10-129112

  However, although the ink jet recording paper described in Patent Document 1 shows improvement in the effect of preventing paper feed scratches, the ink absorbability, the color developability of the printing portion and its preservability, the whiteness of the white paper portion and its preservability Was not satisfactory enough.

In order to prevent paper feed damage by the paper feed roller of the ink jet recording paper, it is considered effective to increase the coating film strength of the coating layer of the ink jet recording paper by pressurizing treatment or the like.
However, when the pressure treatment is performed, it is expected that the pigment and the like in the coating layer are crushed, and therefore the ink absorbability of the ink jet recording paper is lowered.

  The present invention has been made in view of the above circumstances, and provides an ink jet recording paper that satisfies both of the requirements of various ink jet recording papers while achieving both prevention of paper feed damage and good ink absorption. Is. In particular, the present invention provides an ink jet recording paper that exhibits excellent characteristics even when recycled paper recycled pulp is used as a paper base material.

As a result of intensive studies, the inventors have provided an undercoat layer and an ink receiving layer containing titanium dioxide and silica in a specific ratio on a paper substrate, and the above problem is solved by performing a calendar treatment. As a result, the present invention has been completed.
That is, the present invention
(1) An ink jet recording paper in which an undercoat layer and an ink receiving layer are sequentially provided on at least one surface side of a paper base on which pulp is made, and subjected to a calendar treatment, wherein the undercoat layer comprises titanium dioxide and And 10 to 50 parts by mass of silica and an adhesive with respect to 100 parts by mass of the titanium dioxide, and the ink receiving layer comprises silica having an average secondary particle diameter of 3 to 11 μm, an adhesive and a cationic property. An ink jet recording sheet containing an ink fixing agent.
(2) The inkjet recording paper according to (1), wherein a linear pressure in the calendar process is 30 to 100 kg / cm.
(3) The undercoat layer contains, as an adhesive, at least one emulsion-type adhesive selected from an acrylic polymer, an ethylene-vinyl acetate copolymer, and a vinyl acetate polymer ( The inkjet recording paper according to 1) or (2).
(4) The ink receiving layer includes at least a dicyandiamide-polyethyleneamine copolymer and an acrylamide-diallylamine copolymer as the cationic ink fixing agent. The inkjet recording paper described in 1.
(5) The ink jet recording sheet according to (4), wherein the ink receiving layer further contains zinc sulfate as the cationic ink fixing agent.
(6) The inkjet recording according to any one of (1) to (5), wherein at least a part of the silica in the ink receiving layer is a surface-treated silica whose surface is treated with a surfactant. It is paper.
(7) The inkjet recording paper according to any one of (1) to (6), wherein the ink receiving layer contains at least an acrylic polymer as an adhesive.
(8) The inkjet recording paper according to any one of (1) to (7), wherein the 60-degree specular gloss specified by JIS-Z8741 on the surface of the inkjet recording paper is 15% or less. is there.
(9) The inkjet recording paper according to any one of (1) to (8), wherein 10% by mass or more of the pulp content is recycled paper recycled pulp content.
(10) A printed matter printed on the inkjet recording paper according to any one of (1) to (9) with a dye ink.
(11) A printed matter printed on the inkjet recording paper according to any one of (1) to (9) with a pigment ink.

  According to the present invention, it is possible to provide an ink jet recording sheet that satisfies both the prevention of paper feed flaws and good ink absorbability and satisfies the required characteristics of various ink jet recording sheets. In particular, it is possible to provide an ink jet recording paper that exhibits excellent characteristics even when used paper recycled pulp is used as a paper base material.

<Inkjet recording paper>
(Layer structure)
The present invention is an inkjet recording paper in which an undercoat layer and an ink receiving layer are provided on at least one surface side of a paper substrate.
In the present invention, a similar undercoat layer and ink receiving layer may be provided on the other side of the paper substrate. In this case, the effects of the present invention can be exhibited on both sides of the inkjet recording paper.
Each of the undercoat layer and the ink receiving layer may be composed of a plurality of layers.

(Paper substrate)
As pulp used as the main component of the paper base, chemical pulp such as LBKP (hardwood bleached kraft pulp) and NBKP (softwood bleached kraft pulp), mechanical pulp such as GP (ground pulp), TMP (thermomechanical pulp), And recycled paper pulp. These may be used alone or in combination of two or more. In this, it is preferable to mix | blend LBKP as a main component in a pulp.
The beating degree is not particularly limited, but it is preferable to beat so that the freeness (freeness) is about 200 to 500 ml (CSF: JIS-P-8121). If the freeness is small, cockling tends to deteriorate when printed, and if the freeness is large, smoothness tends not to be obtained.

Since the inkjet recording paper of the present invention has an undercoat layer containing a specific material, usually, recycled pulp and mechanical pulp, which are avoided to be used as pulp for inkjet recording paper, are blended into a paper base, An ink jet recording paper having excellent whiteness and storage stability can be obtained.
Of the 100% by mass of pulp used for paper-making on a paper base, it is preferable to use 10% by mass or more of recycled paper because it is possible to use resources effectively by using waste paper.
According to the present invention, even when the total amount of pulp, preferably 10 to 100% by mass, is used as recycled paper, the whiteness of the white portion of the ink jet recording paper and its preservability are good.
Examples of the waste paper used as a raw material for recycled paper pulp include newspaper waste paper, magazine waste paper, paperboard waste paper, wrapping paper waste paper, corrugated paper waste, printed waste paper, and the like, as well as loss of quality paper, coated paper, etc. generated during paper manufacture. Paper may be included.
Waste paper recycled pulp is generally used to dispose of waste paper and waste paper with a low-concentration pulper or a high-concentration pulper, a roughing and selective process using a screen or a cleaner, a deinking process using a flotation method or a water washing method, chlorine bleaching, It can be obtained by appropriately combining bleaching steps such as chlorine bleaching, sodium hypochlorite bleaching and oxygen bleaching.

In addition to the above pulp, a filler is blended in the paper base material.
The filler is blended for the purpose of adjusting the air permeability of the paper substrate, imparting opacity, etc., or adjusting the ink absorbability.
As the filler, for example, clay, kaolin, calcined kaolin, talc, calcium carbonate, magnesium carbonate, aluminum hydroxide, calcium hydroxide, silica, titanium oxide and the like can be used as appropriate. Among these, use of calcium carbonate is preferable because a paper substrate with high whiteness can be obtained.
It is preferable that a filler contains 1-35 mass parts with respect to 100 mass parts of the said whole pulp. If the amount of filler is small, not only will the whiteness decrease, but the ink absorbency will tend to decrease. If it is too much, paper stiffness (stiffness) will tend to decrease and paper strength will decrease. Incorporation into the ink causes yellowing of the ink jet recording paper surface.

Various anionic, nonionic, cationic, or amphoteric yields that have been used in the past are included in the paper stock containing the above pulp and filler during paper making of the paper base, as long as the effects of the present invention are not impaired. Various paper-adding aids such as agents, freeness improvers, paper strength enhancers, and internal sizing agents can be appropriately selected and used as necessary.
Furthermore, paper-made internal additives such as dyes, fluorescent brighteners, pH adjusters, antifoaming agents, pitch control agents, and slime control agents can be added as necessary. In the ink jet recording paper of the present invention, when a large amount of fluorescent brightening agent is blended, the storage stability of the white paper portion may deteriorate.
As a papermaking method, it can be produced using a known papermaking machine such as a long net papermaking machine, a circular netting papermaking machine, or a twin wire type papermaking machine.

The paper base material is classified into acidic paper and neutral paper depending on the pH of the papermaking raw material (stock material). As the paper base material used in the present invention, neutral paper is preferable in terms of long-term storage stability.
In addition, starch, polyvinyl alcohol, cationic resin, or the like can be coated and impregnated on the surface by a size press or the like to adjust surface smoothness, improve strength, printability, and writing ability. Furthermore, in order to improve the smoothness of the paper substrate, it is possible to perform a smoothing process by a calendar method or the like.
The basis weight of the paper substrate is not particularly limited, but is about ²⁰ to 400 g / m ² .

(Undercoat layer)
The undercoat layer in the present invention contains a pigment and an adhesive. As a pigment, titanium dioxide and silica are contained in a specific ratio.

[Pigment]
As a pigment, it is 10-50 mass parts with respect to 100 mass parts of titanium dioxide, Preferably it is used in the ratio of 15-30 mass parts.
The average secondary particle diameter of titanium dioxide is preferably 0.1 μm to 2 μm, and more preferably 0.3 μm to 1 μm. If the particle size is small, the coating film strength, ink absorbability, and color developability of the printed portion tend to decrease.If the particle size is large, the sharpness of the image tends to decrease, and the smoothness is smooth. A uniform surface may not be obtained.
Titanium dioxide has characteristics that white matter is less likely to be preserved and whiteness is higher than other pigments such as kaolin, light calcium carbonate, and talc. Titanium dioxide is classified into a rutile type and an anatase type depending on the difference in structure. In general, the rutile type is preferable because a higher whiteness is obtained, but both types are effective in the present invention.

  Moreover, the amount of adhesive (binder amount) in the undercoat layer can be reduced by using titanium dioxide as a pigment. By reducing the amount of the binder, the ink absorptivity (mainly the absorptivity of the ink solvent) in the undercoat layer is increased, and the resulting inkjet recording paper achieves high-definition image reproduction. Furthermore, reducing the binder amount can also contribute to improving the whiteness of the inkjet recording paper.

As silica, amorphous silica is preferable. The method for producing silica is not particularly limited, and may be produced by any method of an electric arc method, a dry method, and a wet method (for example, a precipitation method and a gel method). This is preferable because it is suitable for both ink jet recording paper and ink jet recording paper for dye ink.
Further, the silica preferably has an average secondary particle size (average particle size of secondary particles; hereinafter sometimes simply referred to as “average particle size”), preferably 3 to 15 μm, and more preferably 4 to 14 μm.
When the average particle diameter of silica is less than 3 μm, the ink absorption during recording with dye ink and pigment ink is hindered, and a clear image tends not to be obtained.
On the other hand, when the average particle diameter of silica exceeds 15 μm, there is a tendency that uneven absorption of ink tends to occur when recording with dye ink and pigment ink.
In addition, in this invention, the average secondary particle diameter of a silica is based on the Cole counter method, and represents the volume average particle diameter measured by using silica dispersed in distilled water for 30 seconds as a sample. It is.
Furthermore, it is preferable that the oil absorption amount according to JIS K-5101 of silica is 210-250 cm < ³ > / 100g from the point which is excellent in the color development property of the printing part at the time of recording with dye ink and pigment ink.

  The undercoat layer in the present invention contains titanium dioxide and silica as pigments in a specific ratio, thereby obtaining excellent color developability and storability of the printed portion, whiteness of the white paper portion and storability thereof. The reason why this effect can be obtained is considered as follows.

Silica is generally known as a pigment used in ink jet recording paper.
Silica has the advantage of superior ink absorption compared to other pigments, but on the other hand, because it has high light, water, and gas permeability, for example, direct ink acceptance on a paper substrate using recycled paper. When the layer is formed, only low whiteness can be obtained, and there is a problem that the color developability of the printing portion is lowered due to low whiteness.
Therefore, even if such an undercoat layer mainly composed of silica is further formed between the paper substrate and the ink receiving layer, sufficient whiteness cannot be obtained.

  In contrast, titanium dioxide has a high light scattering ability and does not cause oxidation of the cationic ink fixing agent, which is presumed to be one of the causes of yellowing of the inkjet recording paper surface. Therefore, by using titanium dioxide as a pigment together with silica to form an undercoat layer, the whiteness of the white paper portion and its storability in the ink jet recording paper are improved, and the color developability and storability of the excellent print portion are improved. Is considered to be obtained.

〔adhesive〕
The undercoat layer in the present invention contains an adhesive.
The adhesive is not particularly limited, but at least one emulsion-type adhesive selected from acrylic polymers, ethylene-vinyl acetate copolymers and vinyl acetate polymers may be used in combination. preferable.

Examples of the acrylic polymer used in the emulsion type adhesive include polymers containing (meth) acrylic units such as acrylic acid, methacrylic acid, acrylic ester, and methacrylic ester. The acrylic polymer may be a homopolymer of (meth) acrylic units, a copolymer, or a copolymer containing other structural units. Examples of the acrylic polymer include polymethyl (meth) acrylate.
As an ethylene-vinyl acetate copolymer, ethylene and vinyl acetate are the main components, and as other monomers, for example, (meth) acrylic esters such as 2-ethylhexyl acrylate, vinyl acetate such as vinyl versatate Examples thereof include those obtained by copolymerizing monomers containing a functional group such as vinyl acid and acrylic acid.
The vinyl acetate polymer may be any polymer containing vinyl acetate units, and polyvinyl acetate is preferred.

  In general, emulsion type adhesives and water-soluble adhesives other than those described above are known as adhesives, but when conjugated diene resins such as styrene-butadiene resin and methyl methacrylate-butadiene copolymer are used for the undercoat layer, The color developability of the printed portion cannot be obtained, and the yellowing of the blank paper portion occurs with time. Also, when using a water-soluble adhesive such as starch or polyvinyl alcohol, when preparing a coating solution for the undercoat layer, it cannot be prepared to a high concentration coating solution. The whiteness of the blank paper portion, its storage stability, and the print density cannot be achieved.

  The mixing ratio of the pigment and the adhesive is about 2 to 30 parts by mass, preferably 5 to 20 parts by mass with respect to 100 parts by mass of the pigment. When the amount of the adhesive is small, the coating strength of the undercoat layer is lowered. On the other hand, when the amount of the adhesive is large, the ink absorption amount is lowered, the color developability of the printed portion is deteriorated and the whiteness tends to be lowered. .

[Other ingredients]
For the undercoat layer, for example, calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, as long as the effects of the present invention are not impaired. Inorganic pigments such as magnesium silicate, aluminum hydroxide, alumina, pseudoboehmite, lithopone, zeolite, hydrous halloysite, magnesium carbonate, and magnesium hydroxide can be blended.

  Further, the undercoat layer is not limited to the effects of the present invention, for example, proteins such as casein, soy protein, synthetic protein, various starches such as starch and oxidized starch, polyvinyl alcohol and derivatives thereof, carboxymethylcellulose, Conventionally known adhesives generally used for inkjet recording, such as cellulose derivatives such as methylcellulose, styrene-butadiene resins, and conjugated diene resins of methyl methacrylate-butadiene copolymers can be used in combination.

  Furthermore, in the undercoat layer, a thickener, an antifoaming agent, a wetting agent, a colorant, a fluorescent dye, a fluorescent pigment, an antistatic agent, which are used in general coated paper production, as long as the effects of the present invention are not impaired. Various auxiliary agents such as a light resistance auxiliary agent, an ultraviolet absorber, an antioxidant and a preservative are appropriately added.

The undercoat layer can be formed by applying an undercoat layer coating solution containing the above pigment, adhesive, and, if desired, an inorganic pigment to the surface of the paper substrate and drying it.
The coating amount (solid content) of the undercoat layer is about 3 to ²⁰ g / m ² , preferably 5 to 15 g / m ² , more preferably 7 to 13 g / m ² . If the coating amount is too small, high whiteness cannot be obtained, and yellowing tends to occur. If the coating amount is excessive, the effect is saturated and the interlayer strength tends to be weakened.

Examples of the coating apparatus for forming the undercoat layer include various known coating apparatuses such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater, and a die coater. Can be mentioned.
In addition, you may finish using calendars, such as a machine calendar, a TG calendar, a super calendar, and a soft calendar, after coating.

(Ink receiving layer)
The ink receiving layer in the present invention contains silica having a specific particle diameter as a pigment, an adhesive, and a cationic ink fixing agent.

[Pigment]
Silica is used as the pigment, and amorphous silica is preferably used.
The method for producing silica is not particularly limited, and may be produced by any method of an electric arc method, a dry method, and a wet method (for example, a precipitation method and a gel method). This is preferable because it is suitable for both ink jet recording paper and ink jet recording paper for dye ink.

Silica having an average secondary particle diameter of 3 to 11 μm is used, and 4 to 10 μm is more preferable.
When the average particle diameter of silica is less than 3 μm, when this is used for ink jet recording paper and printing with dye ink is performed, the absorbability of the dye ink is lowered and the light transmittance is increased, so that the dye ink is used. The light resistance of a printing part falls and the coating-film intensity | strength falls. In addition, when printing is performed with pigment ink using the ink jet recording paper, adverse effects such as deterioration of the fixing property of the pigment ink are caused.
On the other hand, when the average particle diameter of silica exceeds 11 μm, both when the dye ink is used for printing and when the pigment ink is used, the sharpness of the image is deteriorated due to the low printing density, and the surface roughness is conspicuous. This causes problems such as printing unevenness.
Furthermore, it is preferable that the oil absorption amount according to JIS K-5101 of silica is 210-250 cm < ³ > / 100g from the point which is excellent in the color development property of the printing part at the time of recording with dye ink and pigment ink.

In the present invention, as the silica contained in the ink receiving layer, it is preferable to use silica (surface-treated silica) whose surface is treated with a surfactant on at least a part thereof. That is, all of the silica may be surface-treated silica, or both surface-treated silica and untreated silica.
As the untreated silica, the silica used in the above-described invention can be used as it is. As the silica whose surface is treated with a surfactant, the same silica as described above is used.

Examples of the surfactant that treats the surface of silica include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. Among these, nonionic surfactants are exemplified. Agents are preferred.
Specific examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene copolymer, polyoxyethylene polyoxypropylene alkyl ether, and the like. Among these, the HLB value (hydrophilic-lipophilic balance value) is preferably 8.0 to 15.0, and more preferably 10.0 to 12.0. If the HLB value is less than 8.0, a sufficient ink absorption rate tends to be difficult to obtain, and if the HLB value exceeds 15.0, bleeding tends to occur.

As a method for treating the surface of the silica with a surfactant, for example, a method described in JP-A-9-25440 can be employed. That is, it is possible to employ a dry mixing method in which silica, for example, wet method silica, and a surfactant, for example, a multi-chain nonionic surfactant, are mixed with a mixer such as a high-speed flow mixer. In this case, the surfactant may be directly added to and mixed with silica, or the surfactant diluted with a volatile solvent such as ethanol may be added and mixed.
It is also possible to employ a wet processing method in which a predetermined amount of a surfactant, for example, a nonionic surfactant, is added to and mixed with an emulsified slurry of silica, for example, wet method silica, followed by spray drying. it can. In the case of a wet processing method, if the surfactant is poorly soluble in water, it is strongly dispersed in advance to form an emulsion, and this emulsion is added to the pigment emulsified slurry liquid and sufficiently stirred and mixed before drying. Is preferred.
Silica whose surface is treated with a surfactant by such a method is considered to be in a state where the surface is coated with the surfactant.

  The amount of surfactant added to silica is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass per 100 parts by mass of silica. Preferably, when silica coated with a surfactant in such a range is blended, the color developability of the printed portion is improved and a clear image can be obtained.

〔adhesive〕
The adhesive is not particularly limited, and is a water-soluble adhesive such as starch or polyvinyl alcohol, an acrylic polymer, an ethylene-vinyl acetate copolymer, a vinyl acetate polymer, a urethane polymer, or styrene. -Conventionally known adhesives generally used for ink jet recording, such as butadiene copolymers or emulsion type adhesives thereof. These may use only 1 type and may use 2 or more types of adhesives together.

Among the above adhesives, acrylic polymer emulsion adhesives are preferred.
Examples of the acrylic polymer include polymers containing (meth) acrylic units such as acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester.
The acrylic polymer may be a homopolymer of (meth) acrylic units, a copolymer, or a copolymer containing other structural units. Examples of the acrylic polymer include polymethyl (meth) acrylate.

In addition, it is preferable to use polyvinyl alcohol together with an acrylic polymer emulsion-type adhesive because of good adhesion to the pigment.
As the polyvinyl alcohol, polyvinyl alcohol derivatives such as silanol-modified polyvinyl alcohol and cationized polyvinyl alcohol can also be used as appropriate.
In addition, when using together an acrylic polymer and polyvinyl alcohol or its derivative (s), it is preferable to use together by the ratio of 1: 10-2: 1, and it is more preferable to use together by the ratio of 1: 5 to 1: 1.
As content of an acrylic polymer, it is preferable that it is 1-50 mass parts with respect to 100 mass parts of silica, and it is more preferable that it is 5-40 mass parts.

In general, many adhesives such as emulsion type adhesives and water-soluble adhesives are known as adhesives. However, as a result of intensive studies, when acrylic polymer emulsion type adhesives are used, printing can be performed using either dye ink or pigment ink. However, the present inventors have found that a clear image can be obtained and that the preservability of the white paper portion is also excellent.
Incidentally, all of the typical emulsion-type adhesives used in ink jet recording paper are ethylene-vinyl acetate copolymer, vinyl acetate polymer, urethane polymer, styrene-butadiene copolymer, etc. It is inferior to an acrylic polymer in terms of color developability of the printed part, and a urethane polymer and a styrene-butadiene copolymer tend to yellow the blank paper part and are inferior in storage stability of the blank paper part. There is a problem.
In addition, when only water-soluble adhesives such as starch and polyvinyl alcohol are used, sufficient coating strength cannot be obtained, and when preparing a coating solution for the ink receiving layer, a high concentration coating solution is used. There is a problem in that it cannot be prepared and when coated, the coating amount is small and a clear image cannot be obtained.

[Cationic Ink Fixing Agent]
The cationic ink fixing agent is not particularly limited,
1) Polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof,
2) an acrylic polymer having a secondary amino group, a tertiary amino group or a quaternary ammonium group,
3) polyvinylamine, polyvinylamidine, five-membered ring amidines,
4) Dicyan cationic resin represented by dicyandiamide-formalin copolymer,
5) Polyamine cationic resin represented by dicyandiamide-polyethyleneamine copolymer,
6) Dimethylamine-epichlorohydrin copolymer,
7) Diallyldimethylammonium-SO ₂ copolymer,
8) diallylamine salt-SO ₂ copolymer,
9) Dimethyl diallylammonium chloride polymer,
10) Polymer of allylamine salt,
11) Dialkylaminoethyl (meth) acrylate quaternary salt copolymer,
12) Acrylamide-diallylamine salt copolymer,
13) Aluminum salts such as polyaluminum chloride and polyaluminum acetate,
14) Commonly commercially available products such as water-soluble metal salts such as zinc sulfate can be used, and they can be used alone or in combination of two or more.

  Among these, it is preferable to use a dicyandiamide-polyethyleneamine copolymer and an acrylamide-diallylamine copolymer in combination. It is preferable to use these in combination because the color developability of the print portion when recorded with pigment ink, the color developability of the print portion when recorded with dye ink, and the storage stability thereof are excellent. Furthermore, the combined use of zinc sulfate is more preferable because the color developability of the printed portion when printed with pigment ink is greatly improved.

  As a compounding quantity of a cationic ink fixing agent, 5-60 mass parts is preferable with respect to 100 mass parts of silica, More preferably, it adjusts in the range of 20-50 mass parts. If the cationic ink fixing agent is less than 5 parts by mass, the color developability of the printed part and the storage stability of the printed part are liable to occur. Therefore, the sharpness of the image is likely to deteriorate.

For the ink-receiving layer, thickeners, antifoaming agents, wetting agents, surfactants, colorants, antistatic agents, light fastness aids, UV absorbers, antioxidants used in general coated paper production Various auxiliary agents such as preservatives and preservatives are appropriately added.
In the ink jet recording paper of the present invention, a high whiteness can be realized without substantially including a fluorescent brightening agent in the ink receiving layer, so that a good storage stability of the white paper portion can be obtained.

The ink receiving layer is coated on the surface of the undercoat layer formed on the paper substrate with an ink receiving layer coating solution containing silica, an adhesive, a cationic ink fixing agent, and optionally an auxiliary agent, and dried. Can be formed.
The coating amount of the ink receiving layer is not particularly limited, but is preferably ² to 30 g / m ^{2 and} more preferably 5 to ²⁰ g / m ² .
If the coating amount is less than the above lower limit, the ink absorbency, image sharpness, and storability of the printed part are likely to be lowered.If the coating amount is larger than the upper limit, the coating strength and the image sharpness are lowered. easy.
As described above, the ink receiving layer may be composed of a plurality of layers, and in this case, the ink receiving layer composition may be different between the layers.

  The ink receiving layer can be formed by various known coating apparatuses such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater, and a die coater.

(Calendar processing)
The inkjet recording paper of the present invention has been subjected to a calendar process.
Thereby, when feeding ink jet recording paper by the ink jet recording method, it is possible to prevent a paper feed flaw that is a conveyance trace by the paper feed roller. This is considered to be due to the fact that the coating film strength of the coating layer is increased by the calendering process, so that it is difficult to damage the paper feed.
The ink-jet recording paper of the present invention does not lose ink absorbency despite being subjected to a calendar process. This is because, by using titanium dioxide and silica in a specific ratio in the undercoat layer, the silica in the undercoat layer is less likely to be crushed by coexistence with titanium dioxide even when pressure is applied by calendering. ) Is maintained.
As a method of the calendar process, a pressurizing device such as a machine calendar, a super calendar, a soft calendar is used.

The linear pressure in the calendar process is preferably 30 to 100 kg / cm, and more preferably 40 to 70 kg / cm.
By setting the linear pressure of the calendar process to 30 kg / cm or more, the coating film strength of the coating layer is increased, and paper feed damage can be prevented.
By setting the linear pressure of the calendar process to 100 kg / cm or less, better ink absorbability can be obtained. Further, it is possible to suppress the gloss of the high density printed portion that is easily developed when printing with the pigment ink and to prevent the deterioration of the texture.

  Further, as for the glossiness of the surface of the ink jet recording paper, the 60 ° specular glossiness defined in JIS-Z8741 is preferably 15% or less. As a result, a clearer image can be obtained and the texture can be improved.

<Printed matter>
The printed matter of the present invention can be produced by printing on the inkjet recording paper of the present invention with a dye ink or pigment ink using a printer such as a printer.
At this time, paper feed scratches caused by the paper feed roller when feeding the ink jet recording paper by the ink jet recording method are prevented, and good ink absorbability and sufficient color development of the printed part can be achieved using either dye ink or pigment ink. Sex is achieved.
Furthermore, regardless of whether dye ink or pigment ink is used, the storability of the printed part (for example, light resistance, ozone resistance, water resistance) and the storability of the blank paper part (for example, heat resistance, light resistance, ozone resistance) ) Is obtained, and this printed material is suitable for a wide range of uses, for example, for outdoor display.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Moreover, unless otherwise indicated, the part and% in an example are solid content except water, and show a mass part and mass%, respectively. Hereinafter, “secondary particle diameter” means an average secondary particle diameter.

Example 1
[Paper Base A]
Add 20 parts of light calcium carbonate into a slurry of 100 parts of hardwood bleached kraft pulp (freezing degree 400 ml CSF), add 1 part of cationic starch, 0.2 part of alkenyl succinic anhydride neutral sizing agent, Mix and use as a papermaking raw material, dry up to 10% water using a long mesh multi-cylinder paper machine, apply a 7% solution of oxidized starch at 4 g / m ² on both sides with a size press, dry, and 7% water To a paper base A of 200 g / m ² .

[Undercoat layer coating liquid A]
Titanium dioxide (trade name: R-21, secondary particle diameter 0.5 μm, rutile type) 100 parts as pigment and wet silica (trade name: Fine Seal X-60, secondary particle, manufactured by Tokuyama Co., Ltd.), secondary particles diameter 6.2 .mu.m, oil absorption 240 cm ^3/100 g) 20 parts, the acrylic polymer as an adhesive (manufactured by Rohm and Haas, product name: Primal P-376, an emulsion type adhesive) 10 parts of oxidized starch (Oji cornstarch 5 parts (trade name: Ace A, water-soluble adhesive) manufactured by the company were dispersed in water to obtain an undercoat layer coating liquid A.

[Ink-receiving layer coating solution A]
Wet silica as a pigment (manufactured by Tokuyama Corp., trade name: Fine Seal X-60, secondary particle diameter 6.2 .mu.m, oil absorption 240cm ³ / 100g) 100 parts of the silyl-modified polyvinyl alcohol (Kuraray Co. Ltd. as an adhesive, trade name : R-1130) 20 parts and acrylic polymer (Rohm and Haas, trade name: Primal P-376, emulsion type adhesive) 20 parts, acrylamide-diallylamine copolymer (manufactured by Sumitomo Chemical Co., Ltd.) as an ink fixing agent , Trade name: SR1001) 15 parts and dicyandiamide-polyethyleneamine copolymer (manufactured by Nikka Chemical Co., Ltd., trade name: Neofix IJ-117) and zinc sulfate aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd .: zinc sulfate 7 water) Dissolve the Japanese product in water and use it as 5%. Molecular weight 287.56) 10 parts are dispersed in water, and the ink receiving layer is applied. A working liquid A was obtained.

[Preparation of inkjet recording paper]
After coating and drying the undercoat layer coating solution A on the paper substrate A so that the coating amount is 10 g / m ² , the ink receiving layer coating solution A is applied with a coating amount of 10 g / m ² . It was coated and dried.
Thereafter, calendar treatment was performed at a linear pressure of 50 kg / cm to produce an ink jet recording paper.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 2)
[Paper Base B]
20 parts of light calcium carbonate is added to a mixed slurry of 70 parts of hardwood bleached kraft pulp (freeness 400 ml CSF) and 30 parts of deinked pulp (freeness 250 ml CSF), 1 part of cationic starch, anhydrous Add 0.2 part of alkenyl succinic acid neutral sizing agent, mix thoroughly to make papermaking raw material, dry the water to 10% using a long mesh multi-cylinder paper machine, % Solution was applied and dried at 4 g / m ² on both sides, and the moisture was dried to 7% to produce a paper base B having a weight of 200 g / m ² .

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 1 except that the paper base A in Example 1 was changed to the paper base B.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 3)
[Undercoat layer coating solution B]
Titanium dioxide (trade name: R-21, secondary particle diameter 0.5 μm, rutile type) 100 parts as pigment and wet silica (trade name: Fine Seal X-60, secondary particle, manufactured by Tokuyama Co., Ltd.), secondary particles diameter 6.2 .mu.m, oil absorption 240 cm ^3/100 g) 10 parts of the acrylic polymer as an adhesive (manufactured by Rohm and Haas, product name: Primal P-376, an emulsion type adhesive) 10 parts of oxidized starch (Oji cornstarch 5 parts (trade name: Ace A, water-soluble adhesive) manufactured by the company were dispersed in water to obtain an undercoat layer coating solution B.

[Preparation of inkjet recording paper]
An ink jet recording sheet was prepared in the same manner as in Example 2 except that the undercoat layer coating solution A was changed to the undercoat layer coating solution B.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

Example 4
[Undercoat layer coating solution C]
Titanium dioxide (trade name: R-21, secondary particle diameter 0.5 μm, rutile type) 100 parts as pigment and wet silica (trade name: Fine Seal X-60, secondary particle, manufactured by Tokuyama Co., Ltd.), secondary particles diameter 6.2 .mu.m, oil absorption 240 cm ^3/100 g) 50 parts, the acrylic polymer as an adhesive (manufactured by Rohm and Haas, product name: Primal P-376, an emulsion type adhesive) 10 parts of oxidized starch (Oji cornstarch 5 parts (trade name: Ace A, water-soluble adhesive) manufactured by the company were dispersed in water to obtain an undercoat layer coating solution C.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the undercoat layer coating solution A was changed to the undercoat layer coating solution C.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 5)
[Preparation of surface-treated silica]
Wet silica: suspending (manufactured by Tokuyama Corp., trade name Finesil X-60, secondary particle diameter 6.2 .mu.m, oil absorption 240 cm ^3/100 g) to 900g of water, slurry (about 10-15%), and this To the slurry, 100 g of an aqueous suspension of polyoxyethylene lauryl ether (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Neugen ET-102, HLB 10.8) as a surfactant was added and mixed with stirring for 1 hour. Subsequently, it was spray-dried and pulverized and classified to obtain surface-treated silica.
The average secondary particle diameter of the obtained surface-treated silica was 6 μm.

[Ink-receiving layer coating solution B]
Wet silica as a pigment: and (Tokuyama Corp., trade name Finesil X-60, secondary particle diameter 6.2 .mu.m, oil absorption 240cm ³ / 100g) 80 parts of surface-treated silica 20 parts obtained in the above, as the adhesive As 20 parts of silyl-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: R-1130) and 20 parts of an acrylic polymer (trade name: Primal P-376, emulsion type adhesive), ink fixing agent Acrylamide-diallylamine copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: SR1001) 15 parts, dicyandiamide-polyethyleneamine copolymer (manufactured by Nikka Chemical Co., Ltd., trade name: Neofix IJ-117) and zinc sulfate aqueous solution ( Wako Pure Chemical Industries, Ltd .: Zinc sulfate heptahydrate dissolved in water and used as 5%, molecular weight 287.56) 10 Parts were dispersed in water to obtain an ink receiving layer coating solution B.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the ink receiving layer coating liquid A in Example 2 was changed to the ink receiving layer coating liquid B.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 6)
[Ink-receiving layer coating solution C]
Wet silica as a pigment (manufactured by Tokuyama Corp., trade name: Fine Seal X-60, secondary particle diameter 6.2 .mu.m, oil absorption 240cm ³ / 100g) 100 parts of the silyl-modified polyvinyl alcohol (Kuraray Co. Ltd. as an adhesive, trade name : R-1130) 20 parts and acrylic polymer (Rohm and Haas, trade name: Primal P-376, emulsion type adhesive) 20 parts, acrylamide-diallylamine copolymer (manufactured by Sumitomo Chemical Co., Ltd.) as an ink fixing agent , Trade name: SR1001) and 15 parts of dicyandiamide-polyethyleneamine copolymer (manufactured by Nikka Chemical Co., Ltd., trade name: Neofix IJ-117) were dispersed in water to obtain an ink receiving layer coating liquid C. .

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the ink receiving layer coating liquid A in Example 2 was changed to the ink receiving layer coating liquid C.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 7)
[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the linear pressure of the calendar process in Example 2 was changed to 30 kg / cm.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Example 8)
[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the linear pressure of the calendar process in Example 2 was changed to 100 kg / cm.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

Example 9
[Preparation of inkjet recording paper]
Inkjet recording paper was prepared in the same manner as in Example 4 except that the linear pressure of the calendar process in Example 4 was changed to 150 kg / cm.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 4%.

(Comparative Example 1)
[Preparation of inkjet recording paper]
On the paper substrate B, the ink receiving layer coating solution A is applied and dried so that the coating amount is 10 g / m ^2, and then calendered at a linear pressure of 50 kg / cm to provide an undercoat layer. Inkjet recording paper was prepared.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Comparative Example 2)
[Undercoat layer coating solution D]
Titanium dioxide as a pigment (manufactured by Sakai Chemical Co., Ltd., trade name: R-21, secondary particle size 0.5 μm, rutile type) 100 parts, acrylic polymer (made by Rohm and Haas, trade name: Primal P as an adhesive) -376, emulsion-type adhesive) 10 parts and oxidized starch (manufactured by Oji Cornstarch Co., Ltd., trade name: Ace A, water-soluble adhesive) were dispersed in water to obtain an undercoat layer coating liquid D.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the undercoat layer coating solution A was changed to the undercoat layer coating solution D.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Comparative Example 3)
[Undercoat layer coating solution E]
Titanium dioxide (trade name: R-21, secondary particle diameter 0.5 μm, rutile type) 100 parts as pigment and wet silica (trade name: Fine Seal X-60, secondary particle, manufactured by Tokuyama Co., Ltd.), secondary particles diameter 6.2 .mu.m, oil absorption 240 cm ^3/100 g) 80 parts of the acrylic polymer as an adhesive (manufactured by Rohm and Haas, product name: Primal P-376, an emulsion type adhesive) 10 parts of oxidized starch (Oji cornstarch 5 parts (trade name: Ace A, water-soluble adhesive) manufactured by the company were dispersed in water to obtain an undercoat layer coating solution E.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the undercoat layer coating solution A was changed to the undercoat layer coating solution E.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

(Comparative Example 4)
[Ink-receiving layer coating solution D]
Wet silica as a pigment (manufactured by Tokuyama Corp., trade name: Fine Seal F80, secondary particle diameter 1.8 .mu.m, oil absorption 240cm ³ / 100g) 100 parts of the silyl-modified polyvinyl alcohol (Kuraray Co. Ltd. as an adhesive, trade name: R -1130) 20 parts and acrylic polymer (Rohm and Haas, product name: Primal P-376, emulsion type adhesive) 20 parts, acrylamide-diallylamine copolymer (manufactured by Sumitomo Chemical Co., Ltd., product) as an ink fixing agent Name: SR1001) 15 parts and dicyandiamide-polyethyleneamine copolymer (manufactured by Nikka Chemical Co., Ltd., trade name: Neofix IJ-117) and zinc sulfate aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd .: zinc sulfate heptahydrate) Dissolved in water and used as 5%, molecular weight 287.56) 10 parts dispersed in water, ink receiving layer coating Liquid D was obtained.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the ink receiving layer coating liquid A in Example 2 was changed to the ink receiving layer coating liquid D.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 4%.

(Comparative Example 5)
[Ink-receiving layer coating solution E]
Wet silica as a pigment (manufactured by Mizusawa Industrial Chemicals, Ltd., trade name: Mizukasil P-78F, secondary particle diameter 12.5 .mu.m, oil absorption 230cm ³ / 100g) 100 parts of the silyl-modified polyvinyl alcohol (Kuraray Co. Ltd. as an adhesive, trade name : R-1130) 20 parts and acrylic polymer (Rohm and Haas, trade name: Primal P-376, emulsion type adhesive) 20 parts, acrylamide-diallylamine copolymer (manufactured by Sumitomo Chemical Co., Ltd.) as an ink fixing agent , Trade name: SR1001) 15 parts and dicyandiamide-polyethyleneamine copolymer (manufactured by Nikka Chemical Co., Ltd., trade name: Neofix IJ-117) and zinc sulfate aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd .: zinc sulfate 7 water) Dissolve the Japanese product in water and use it as 5%. Molecular weight 287.56) 10 parts are dispersed in water, and the ink receiving layer is applied. A working fluid E was obtained.

[Preparation of inkjet recording paper]
An ink jet recording paper was prepared in the same manner as in Example 2 except that the ink receiving layer coating liquid A in Example 2 was changed to the ink receiving layer coating liquid E.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 4%.

(Comparative Example 6)
[Preparation of inkjet recording paper]
Inkjet recording paper was prepared in the same manner as in Example 2 except that the calendar process in Example 2 was changed to uncalendered.
The 60 ° specular glossiness defined by JIS-Z8741 in the white paper portion of the ink receiving layer surface of the obtained ink jet recording paper was 3%.

<Evaluation>
About the ink jet recording paper obtained in each Example and Comparative Example, paper feed scratch prevention, ink absorption, ink fixing, printing portion glossiness, printing density, printing portion storability (light resistance, ozone resistance) Properties, water resistance), whiteness of the white paper portion, and storage stability of the white paper portion (prevention of thermal yellowing, prevention of light yellowing, prevention of ozone yellowing) were evaluated by the following methods.
Here, the color developability of the print portion was evaluated by the print density.
In the evaluation, printing on inkjet recording paper was performed using commercially available dye inkjet printers (manufactured by EPSON, trade name: PM-G800, printing mode: photomat paper / high definition), commercially available pigment inkjet printers (manufactured by EPSON). , Trade name: PX-G900, print mode: photo matte paper / high definition, commercially available pigment ink jet printer (manufactured by EPSON, trade name: PM-4000PX, ink: matte black used, print mode: photomat paper / high Fine) and a commercially available pigment inkjet printer (manufactured by EPSON, trade name: PX-6000, print mode: photomat paper / clean).

[Prevention of paper feed scratches]
Among the print density evaluations described above, the highest black tone portion of the recorded matter printed by a commercially available pigment ink jet printer (manufactured by EPSON, trade name: PX-6000, print mode: photomat paper / clean), The presence or absence of paper feed scratches generated by the paper feed roller was observed and evaluated according to the following criteria.
○: Paper feed scratches by the paper feed roller are not recognized in the printing section.
Δ: Slightly damaged paper feed due to paper feed roller is observed in the printing section.
X: Paper feed damage by the paper feed roller is observed in the printing section.

[Ink absorbency]
Among the print density evaluations described above, the highest black tone portion of the recorded matter printed by a commercially available dye inkjet printer (manufactured by EPSON, trade name: PM-G800, print mode: photomat paper / high definition) Observed and evaluated according to the following criteria.
○: No ink overflow, blurring or unevenness.
Δ: In some cases, ink overflow, blurring, and unevenness are present, but there is no practical problem.
X: The ink overflows and unevenness occurs.

[Ink fixability]
Among the print density evaluations described above, the recorded matter printed with a commercially available pigment inkjet printer (manufactured by EPSON, trade name: PM-4000PX, ink: matte black used, print mode: photomat paper / high definition) The highest color tone portion of black was rubbed with a finger one day after printing and evaluated according to the following criteria.
○: There is no change in the printed part even when rubbing with a finger.
X: The printed part peels off when rubbed with a finger.

[Glossiness of printed part]
85 degree gloss specified by JIS-Z8741 of the highest density black portion printed by a commercially available pigment inkjet printer (manufactured by EPSON, trade name: PM-4000PX, ink: matte black used, print mode: photomat paper / clean) The degree was measured.
○: Glossiness is less than 20% △: Glossiness is 20% or more and less than 25% ×: Glossiness is 25% or more

[Print density]
An image issued by the Japanese Standards Association ("High-definition color digital standard image XYZ / JIS-SCID", identification symbol: S6, image name: color chart) is printed on each of the above four models, and the highest color tone of black The print density of each part was measured with RD-914 manufactured by GretagMacbeth.

[Preservation of printed part (light resistance)]
Using a commercially available dye ink jet printer (manufactured by EPSON, trade name: PM-G800, print mode: photomat paper / high definition), a recorded matter printed at a magenta print density of 1.0 is printed at 24 ° C. In a 60% RH (humidity) environment, a fluorescent lamp with an illuminance of 70 Klux was irradiated for 500 hours, and the print density was measured. However, 2 mm thick glass was placed on the recorded material.
The storage stability (light resistance) of the printed part at this time was evaluated according to the following criteria.
A: Density change is less than 15% B: Density change is 15% or more and less than 20% B: Density change is 20% or more and less than 30% X: Density change is 30% or more

[Preservation of printed part (ozone resistance)]
Using a commercially available dye ink jet printer (manufactured by EPSON, trade name: PM-G800, print mode: photomat paper / high definition), a recorded matter printed at a magenta print density of 1.0 is printed at 24 ° C. In a 60% RH (humidity) environment, it was left in an atmosphere with an ozone concentration of 10 ppm for 24 hours, and the printing density was measured.
The storage stability (ozone resistance) of the printed part at this time was evaluated according to the following criteria.
○: Concentration change is less than 15% △: Concentration change is 15% or more and less than 30% ×: Concentration change is 30% or more

[Preservation of printed part (water resistance)]
Using a commercially available dye ink jet printer (manufactured by EPSON, trade name: PM-G800, printing mode: photomat paper / high definition), 30-point characters are printed at the highest black density, and water drops are dropped on it. Naturally dry.
The storage stability (water resistance) of the printed portion at this time was evaluated according to the following criteria.
○: Slight bleeding occurs but there is no problem in character discrimination.
×: Bleeding occurs, and there is a problem in character discrimination.

[Whiteness of blank page]
The whiteness of the white paper portion on the ink receiving layer side of the ink jet recording paper was measured according to the method defined in JIS-P8123.

[Preservation of blank paper part (prevents thermal yellowing)]
The ink jet recording paper was allowed to stand for 1 week in an environment of 80 ° C. and 50% RH (humidity). Before and after standing, the hue b * value of the white paper portion on the ink receiving layer side of the inkjet recording paper was measured. For the measurement, 938 Spectrodensti manufactured by X-rite
ometer was used.
Next, Δb * value was calculated according to the following equation.
Δb * value = | b * value after standing |-| b * value before standing |
The storage stability (prevention of thermal yellowing) of the blank paper portion was evaluated according to the following criteria.
◯: Δb * value is less than 3 and hardly yellowed.
Δ: Δb * value is 3 or more and less than 6, and yellowing occurs.
X: Δb * value is 6 or more, and it is very yellowed.

[Preservation of blank paper part (prevents light yellowing)]
The ink jet recording paper was irradiated with a xenon lamp (100,000 lux) for 3 days in an environment of 60 ° C. and 50% RH (humidity).
Before and after irradiation, the hue b * value of the white paper portion on the ink receiving layer side of the inkjet recording paper was measured. For the measurement, a 938 spectrodensimeter manufactured by X-rite was used.
Next, Δb * value was calculated according to the following equation.
Δb * value = | b * value after irradiation |-| b * value before irradiation |
The storage stability (prevention of light yellowing) of the blank paper portion was evaluated according to the following criteria.
◯: Δb * value is less than 3 and hardly yellowed.
Δ: Δb * value is 3 or more and less than 6, and yellowing occurs.
X: Δb * value is 6 or more, and it is very yellowed.

[Preservation of white paper part (prevention of ozone yellowing)]
The inkjet recording paper was left in an atmosphere of ozone concentration 10 ppm for 24 hours in an environment of 24 ° C. and 60% RH (humidity).
The hue b * value of the white paper portion on the ink receiving layer side of the inkjet recording paper was measured before and after being left. For the measurement, a 938 spectrodensimeter manufactured by X-rite was used.
Next, Δb * value was calculated according to the following equation.
Δb * value = | b * value after irradiation |-| b * value before irradiation |
The preservability (prevention of ozone yellowing) of the blank paper portion was evaluated according to the following criteria.
◯: Δb * value is less than 3 and hardly yellowed.
Δ: Δb * value is 3 or more and less than 6, and yellowing occurs.
X: Δb * value is 6 or more, and it is very yellowed.

From the results shown in Table 1, it was found that Examples 1 to 9 are both excellent in the required characteristics of the ink jet recording paper, with both prevention of paper feeding flaws and ink absorption.
In particular, in Examples 1 to 8 in which the linear pressure of the calendar process was in the range of 30 to 100 kg / cm, it was found that the gloss of the printed portion was not too high.
Further, as the cationic ink fixing agent, Example 2 in which zinc sulfate was further used in combination with dicyandiamide-polyethyleneamine copolymer and acrylamide-diallylamine copolymer, compared with Example 6 in which zinc sulfate was not used in combination, the printing density. As a result, the color development of the printed portion was further improved.
Further, Example 5 in which the surface-treated silica whose surface was treated with a surfactant was used in combination with the silica in the ink receiving layer had a higher print density than in Example 2 in which the surface-treated silica was not used in combination. It was found that the color development of the part was further improved.
From Example 2 in which the pulp obtained by deinking the newspaper waste paper was blended with the paper base material and Example 1 in which the pulp was not blended, it was found that the performance of the ink jet recording paper was maintained even when used paper recycled pulp was used. .
On the other hand, in Comparative Example 1 having no undercoat layer, it was found that the print density was low, and the whiteness of the white paper portion and its storage stability were poor.
It was found that Comparative Example 2 in which no silica was contained in the undercoat layer had poor ink absorbability, and Comparative Example 3 in which the content of silica in the undercoat layer was excessive was inferior in storage stability of the blank paper portion.
In Comparative Example 4 in which the average secondary particle diameter of silica in the ink receiving layer is 1.8 μm, both the prevention of paper feed flaws and the ink absorbency are both poor, the print density is too high, and the gloss of the printed part Unevenness) occurred, and the storability of the printed part was found to be poor.
It was found that Comparative Example 5 in which the average secondary particle diameter of silica in the ink receiving layer was 12.5 μm had a low printing density and was inferior in the color developability of the printing portion.
Further, it was found that Comparative Example 6 that was not subjected to the calendar process was poor in preventing paper feed damage.

Claims (11)

  An ink jet recording paper in which an undercoat layer and an ink receiving layer are sequentially provided on at least one surface side of a paper substrate on which pulp is made, and subjected to a calendar treatment, wherein the undercoat layer comprises titanium dioxide and the carbon dioxide. It contains 10 to 50 parts by mass of silica with respect to 100 parts by mass of titanium and an adhesive, and the ink receiving layer comprises silica having an average secondary particle diameter of 3 to 11 μm, an adhesive, and a cationic ink fixing agent. And an ink jet recording paper.   2. The ink jet recording paper according to claim 1, wherein a linear pressure in the calendar process is 30 to 100 kg / cm.   The undercoat layer contains at least one emulsion-type adhesive selected from an acrylic polymer, an ethylene-vinyl acetate copolymer, and a vinyl acetate polymer as an adhesive. 2. Inkjet recording paper according to item 2.   The ink receiving layer contains at least dicyandiamide-polyethyleneamine copolymer and acrylamide-diallylamine copolymer as the cationic ink fixing agent. Inkjet recording paper.   The inkjet recording paper according to claim 4, wherein the ink receiving layer further contains zinc sulfate as the cationic ink fixing agent.   The inkjet recording paper according to any one of claims 1 to 5, wherein at least a part of the silica in the ink receiving layer is surface-treated silica whose surface is treated with a surfactant.   The ink jet recording sheet according to claim 1, wherein the ink receiving layer contains at least an acrylic polymer as an adhesive.   The inkjet recording paper according to any one of claims 1 to 7, wherein the 60-degree specular gloss specified by JIS-Z8741 on the surface of the inkjet recording paper is 15% or less.   The inkjet recording paper according to any one of claims 1 to 8, wherein 10% by mass or more of the pulp content is recycled paper recycled pulp content.   The printed matter printed on the inkjet recording paper as described in any one of Claims 1-9 with dye ink.   The printed matter printed on the inkjet recording paper as described in any one of Claims 1-9 with the pigment ink.