JP5872198B2 - Inkjet recording sheet - Google Patents

Description

  The present invention relates to an ink jet recording sheet, and more particularly to an ink jet recording sheet having a porous recording layer structure.

  Currently, various ink jet recording sheets are commercially available, but these products employ a porous recording layer structure to improve ink acceptability, so that they can interact with various surrounding substances. Can not be ignored, it can be said that there are many noticeable discoloration over time. Further, if a large design change is made to the basic structure in order to improve the discoloration, the ink jet printing characteristics may be deteriorated.

  As an example of studying measures for improving discoloration with respect to an ink jet recording sheet, for example, there are the following.

  Patent Document 1 is characterized in that, in an ink jet recording sheet having at least one ink-receiving layer on a water-resistant support, the ink-receiving layer contains vapor-phase silica and a silane coupling agent. Inkjet recording sheets are introduced. Patent Document 2 describes that, in an inkjet recording sheet having a colorant receiving layer on a support, discoloration of printing can be suppressed by introducing various defined compounds into the layer. There is.

JP 2000-233572 A JP 2003-305949 A

  However, according to the configuration described in Patent Document 1, although discoloration of the base paper is improved by protecting active hydroxyl groups on the silica surface, on the other hand, depending on the amount of silane coupling agent added, inkjet ink The affinity of is impaired. In addition, since most of the silane coupling agent is non-aqueous, there may be a problem of workability in preparing the coating liquid, and the reaction of the silane coupling agent is a dehydration polycondensation system. Depending on the reaction state, the effect may not be as good as the added amount. In addition, silane coupling agents are also more expensive than common paper industry additives, and thus suffer from economic disadvantages.

  Also, in Patent Document 2, when the compound formula described is seen, the skeleton is symmetrical, the conjugated double bond has a short distance, and the side chain is selected to have a relatively low reactivity. It can be read that the interaction with other substances is weak, but there are few ionic functional groups per unit molecular weight, and depending on the amount added, the affinity of the water-based ink is impaired. In addition, the compound formula has been subjected to a multi-step synthesis process from the amount and diversity of the molecular chain, and is easily estimated to be expensive, and it is doubtful whether it is optimal as an economic choice. In addition, although there is a description about discoloration of printing, there is no description about discoloration of base paper.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is for ink-jet recording in which discoloration that has been a problem is improved while maintaining conventional good ink-jet suitability or print quality. To provide a sheet.

  Further, other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the following description.

  As a result of intensive studies, the present inventors have obtained the inkjet recording sheet of the present application. An inkjet recording sheet according to the present application includes a sheet-like support mainly composed of pulp, a porous fine-particle inorganic pigment, a water-soluble adhesive, and a cation on one or both sides of the sheet-like support. A predetermined amount of the porous fine inorganic pigment loses surface activity contributing to discoloration of the recording layer. It is a porous fine particle inorganic pigment that has been subjected to active treatment.

  According to such a configuration, a predetermined amount of the porous fine particulate inorganic pigment used in the recording layer is obtained by deactivating the surface activity that contributes to the discoloration of the recording layer. Ink jet recording sheet can be obtained which does not decrease the color and has little discoloration over time.

  In a preferred embodiment of the present application, the deactivation treatment is located on the surface of the porous fine particle inorganic pigment, or a coating treatment in which the porous fine particle inorganic pigment surface is coated with a predetermined coating agent. In addition, a desensitization treatment may be used in which a functional group contributing to discoloration is desensitized using a predetermined desensitizer.

  According to such a configuration, since the functional group contributing to discoloration is deactivated by physical protection by coating or by desensitization by a desensitizing agent, the ink absorption state and the recording layer strength are improved. Is maintained, the discoloration preventing effect is further improved.

  Here, in a preferred embodiment of the present application, the predetermined coating agent may be various waxes. In addition, the predetermined desensitizer may include a silane coupling agent, various metal ions having a positive charge, particulate metal or metal oxide, a surfactant, an organic binder, or an inorganic binder.

  Moreover, in preferable embodiment of this application, the range of 200-334 mass parts with respect to 100 mass parts of said water-soluble adhesives may be sufficient as the compounding quantity of the said porous fine particle inorganic pigment.

  According to such a configuration, an ink jet recording sheet having a good balance between ink absorbability and recording layer strength can be obtained.

  Moreover, in preferable embodiment of this application, the range of 5-30 mass parts may be sufficient as the compounding quantity of the said cationic ink fixing agent with respect to 100 mass parts of porous particulate inorganic pigments.

  According to such a configuration, an ink jet recording sheet having excellent effects in both print quality and ink discoloration suppression can be obtained.

Moreover, in preferable embodiment of this application, the range of 5-20 g / m < ² > per surface may be sufficient as the application quantity of the said coating liquid in a dry state.

  According to such a configuration, an inkjet recording sheet having a good balance between inkjet suitability and recording layer strength can be obtained.

  In a preferred embodiment of the present application, the porous fine particle inorganic pigment may include silica, alumina, magnesia, titania, or apatite.

  According to such a configuration, since an inorganic pigment having excellent affinity with the inkjet ink is selected, an inkjet recording sheet having excellent inkjet suitability and good image quality can be obtained.

  Further, in a preferred embodiment of the present application, when the porous particulate inorganic pigment is silica and the total amount of the particulate inorganic pigment is 100 parts by mass, the surface activity is deactivated. The predetermined amount of the inorganic pigment may be in the range of 10 to 80 parts by mass.

  According to such a configuration, an ink jet recording sheet having a good balance between ink absorptivity and discoloration preventing effect can be obtained.

  Moreover, in preferable embodiment of this application, the range of 20-60 mass parts may be sufficient as the predetermined amount of the particulate inorganic pigment in which the surface activity was deactivated.

  According to such a configuration, an ink jet recording sheet having a more excellent discoloration preventing effect can be obtained.

  In a preferred embodiment of the present application, the deactivation treatment may be a desensitization treatment using a silane coupling agent.

  According to such a configuration, an ink jet recording sheet having a better balance between ink absorptivity and discoloration prevention effect can be obtained.

  According to the ink jet recording sheet of the present invention, the predetermined amount of the porous fine-particle inorganic pigment used in the recording layer has been subjected to the deactivation treatment of the surface activity contributing to the color change of the recording layer. An ink jet recording sheet that does not deteriorate the ink jet printing quality and has little discoloration over time can be obtained.

It is a graph which shows the physical-property evaluation result of an Example and a comparative example.

  Hereinafter, an ink jet recording sheet according to the present invention will be described in detail with reference to the accompanying drawings.

  As described above, the ink jet recording sheet according to the present invention is a sheet-like support, on one side or both sides of the sheet-like support, a porous fine-particle inorganic pigment, a water-soluble adhesive, And a recording layer formed by applying a coating liquid containing a cationic ink fixing agent, and a predetermined amount of the porous fine-particle inorganic pigment contributes to discoloration of the recording layer. Is a porous fine-particle inorganic pigment that has been subjected to a deactivation treatment.

  Here, as a raw material for the support of the present invention, chemical pulp such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), and other general paper pulp such as ground pulp and deinked wastepaper pulp, etc. Pulp can be used alone or in combination of two or more. Among them, it is preferable to use pulp mainly composed of wood fibers from the viewpoint of cost and whiteness. In addition, these raw material pulps may be used in combination with one or more of various additives such as conventionally known fillers, binders, sizing agents, fixing agents, yield improvers, paper strength enhancers as required. Also good.

  The support of the ink jet recording sheet according to the present invention is mixed with one or two or more various additives as necessary to the raw material pulp, and the long net paper machine, circular net paper machine, twin wire paper machine. It can be obtained by forming a web with various paper machines such as the following and then drying it.

  The surface of the obtained support is coated with a surface paper strength enhancer using a device such as a size press, gate roll, or sizer for the purpose of imparting strength before providing a coating layer. Also good. Examples of the surface paper strength enhancer include starch, polyacrylamide, polyvinyl alcohol, and carboxymethyl cellulose.

  As described above, the recording layer provided on one side or both sides of the support according to the present application is a coating liquid containing a porous fine-particle inorganic pigment, a water-soluble adhesive, and a cationic ink fixing agent. And a predetermined amount of the porous fine-particle inorganic pigment is a porous fine-particle inorganic pigment whose surface activity contributing to discoloration of the recording layer has been deactivated.

  In this application, it is preferable that the addition amount of the said porous particulate inorganic pigment shall be 200-334 mass parts with respect to 100 mass parts of water-soluble adhesives. When the addition amount of the porous fine-particle inorganic pigment is less than 200 parts by mass, there is a possibility that sufficient ink absorbability cannot be ensured due to the small addition amount, and the printing quality is inferior. On the other hand, if the amount of the porous fine-particle inorganic pigment added is more than 334 parts by mass, the ink absorption is excellent, but the use ratio of the water-soluble adhesive is reduced, leading to a decrease in the recording layer strength. There is a possibility that troubles may occur due to contamination of the conveyance roll of the ink jet printer or cutting paper powder in post-processing. In the case where the effect of preventing discoloration is more important, it is desirable that the amount of the porous fine-particle inorganic pigment added is small, and is 200 to 250 parts with respect to 100 parts by mass of the water-soluble adhesive. Is more preferable.

  As the porous fine particle inorganic pigment to be contained in the recording layer, inorganic pigments such as silica, alumina, magnesia, titania, and hydroxyapatite are preferable. Since these inorganic pigment particles have a hydrophilic surface, they have excellent affinity with ink-jet inks. In addition, since the particles themselves are porous, they also have excellent ink absorbability. The ink jet ink adhering to the surface of the layer is quickly absorbed, so that the image quality of the ink jet printing is improved. Among the above-described inorganic materials, fine particle silica is particularly preferable because of excellent ink absorbability and suitable ink jet aptitude.

  Further, as the porous fine particle inorganic pigment whose surface activity contributing to the discoloration of the recording layer is deactivated, those obtained by deactivating inorganic pigments such as silica, alumina, magnesia, titania, and hydroxyapatite are preferable. However, silica is preferable in terms of ink jet printing suitability. However, active functional groups (hydroxyl groups in the case of silica) on the surface of these inorganic pigments become the starting point of the reaction, which may affect various discolorations. Therefore, it is considered that an effect can be obtained in discoloration improvement of the ink jet recording sheet by deactivating this reactive functional group by some means.

  Specifically, a predetermined amount of the inorganic pigment is coated with a certain substance on the surface, or a deactivation treatment such as protecting active functional groups on the surface with chemicals leads to prevention of discoloration. It is considered a thing.

  As the deactivation treatment of the inorganic pigment surface, a coating treatment that coats the surface of the porous fine particle inorganic pigment with a predetermined coating agent, or a function that is located on the surface of the porous fine particle inorganic pigment and contributes to discoloration. A desensitization treatment in which a group is desensitized using a predetermined desensitizer is exemplified. As the coating agent, various waxes, organic binders, inorganic binders and the like are preferable, and as the desensitizer, surfactants, silane coupling agents, various metal ions having positive charge, fine metal or metal oxide, etc. However, it is not limited as long as the silica surface can be protected without impairing the ink absorbability. For example, commercially available products include Nipgel AZ360 (silica surface-treated with wax) manufactured by Tosoh Silica. The important characteristics of such surface-treated silica are that the ink absorbability is maintained in a good state, the strength of the coating layer is not reduced due to the inclusion thereof, and it contains For example, the alteration of the coating layer itself due to the reduction of the coating layer can be reduced.

  However, an inorganic pigment whose surface has been subjected to deactivation treatment can provide an effect of preventing discoloration, but on the other hand, it becomes inferior in ink jet printing suitability as compared with an inorganic pigment that has not been subjected to deactivation treatment. .

  That is, the inorganic pigment that has been subjected to the deactivation treatment and the inorganic pigment that has not been subjected to the deactivation treatment each have different merits and demerits. It is considered that an ink jet recording sheet having both excellent ink jet printing suitability can be obtained.

  In the present invention, the preferred blending ratio of the porous fine particulate inorganic pigment is such that when the blending amount of the whole fine particulate inorganic pigment used is 100 parts by mass, the ratio of the porous inorganic pigment subjected to the surface treatment is 10 to 10. It is preferably in the range of 80 parts by mass, and more preferably in the range of 20 to 60 parts by mass. When the blending ratio of the surface-treated porous fine-particle inorganic pigment is less than 10 parts by mass with respect to the total amount of the inorganic pigment, good ink absorbability can be obtained, but the anti-discoloration effect tends to be bad. It is. In addition, when the ink absorbency is excessive, the printing density tends to decrease. On the other hand, when the blending ratio of the surface-treated porous silica is more than 80 parts by mass, a good discoloration preventing effect can be obtained, but sufficient ink absorbability cannot be ensured and printing quality deteriorates. There is a risk.

  Examples of the water-soluble adhesive used in the recording layer of the present invention include cellulose derivatives such as polyvinyl alcohol, polyethylene vinyl acetate, hydroxyethyl cellulose, and carboxymethyl cellulose, and various latexes such as SBR, NBR, acrylic latex, and chloroprene latex. These water-soluble adhesives may be used alone or in combination of two or more. In particular, from the viewpoint of ink absorptivity, it is preferable to use a resin such as polyvinyl alcohol or polyethylene vinyl acetate, and from the viewpoint of alteration such as prevention of strength deterioration due to light or prevention of discoloration, latex and urethane are not preferable. For this reason, among the above-mentioned water-soluble adhesives, examples such as polyvinyl alcohol, polyethylene vinyl acetate, and acrylic are more preferable.

  The recording layer of the present invention contains an ink fixing agent in order to improve the fixability of the inkjet ink. Since the ink jet ink is anionic, a fixing agent having a cationic property is necessary. Without using this cationic ink fixing agent, it is difficult to increase the print density and the water resistance of the ink is also inferior. . On the other hand, if the amount of the cationic ink fixing agent used is excessive, the color development of the ink may be impaired, the ink may be deteriorated, and the durability of the ink may be increased by light or heat. To become inferior.

  Therefore, the addition amount of the cationic ink fixing agent has a preferable range in which both the print density and the color developability can be achieved. The setting of this range is influenced by factors such as the combination of the types of inkjet ink and cationic ink fixing agent to be used, the target of print density and color tone, and the quality level setting such as water resistance and light resistance. To do.

  In the inkjet recording sheet of the present invention, the addition amount of the cationic ink fixing agent contained in the coating layer is in the range of 5 to 30 parts by mass with respect to 100 parts by mass of the porous fine-particle inorganic pigment. Is preferable, and the range of 10 to 20 parts by mass is more preferable. This more preferable range is considered to be an optimum condition effective for both print quality and ink discoloration suppression.

  In the present application, generally known cationic ink fixing agents for use in the recording layer can be used, such as amine epichlorohydrin polycondensate, dimethyldiallylammonium chloride polymer, alkylamine quaternized product, dicyandiamide, acrylamide dimethylammonium. A cationic ink fixing agent such as a chloride copolymer can be used alone or in combination of two or more. As the cationic ink fixing agent, an amine-based compound is generally used, and the lower the lower in terms of preventing discoloration, the more advantageous, but the print density tends to be inferior.

  The coating liquid used for the recording layer of the present invention includes, in addition to inorganic pigments, water-soluble adhesives, and cationic ink fixing agents, coloring agents such as coloring pigments and coloring dyes, dispersants, and antifoaming as necessary. Additives for papermaking, such as additives, viscosity modifiers, crosslinking agents, mold release agents, preservatives, softeners, waxes, antistatic agents, antistatic agents, perfumes, deodorants, flameproofing agents, repellents, rust inhibitors Can be used as appropriate.

  In the present invention, regarding the coating treatment for providing the recording layer, it can be applied to a support using a known general coating machine, for example, a blade coater, a roll coater, an air knife coater, a rod coater, or the like. .

In addition, the coating amount of the coating liquid is preferably in the range of 5 to ²⁰ g / m ² per side in terms of dry coating amount. If the dry coating amount per side is less than 5 g / m ² , it is difficult for the recording layer to completely cover the support surface, and there is a possibility of being inferior in terms of inkjet suitability. On the contrary, if the dry coating amount per side exceeds 20 g / m ² , the adhesive strength between the recording layer and the support may not be practically usable, and powder may fall off during cutting. There is a possibility that the printing durability at the time of printing becomes inferior.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show the mass part and the mass%, respectively.

<Creation of base paper>
A pulp slurry of 100 parts of LBKP (Canadian Standard Freeness: CSF = 500 ml) was made with a long net paper machine to obtain a base paper having a basis weight of 180 g / m ² .
<Preparation of coating solution for coating layer>
40 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 7 μm as an inorganic pigment not subjected to deactivation treatment, and an average particle diameter as an inorganic pigment subjected to deactivation treatment 60 parts of 3.5 μm synthetic amorphous silica (trade name: Nipgel AZ360 (porous synthetic silica surface-treated with wax), manufactured by Tosoh Silica Co., Ltd.), water, and 0.5 parts of acetic acid as a pH adjuster And a 28% pigment slurry was prepared in a cowless disperser. To this pigment slurry, 15 parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) and 25 parts of polyethylene vinyl acetate binder (trade name: Sumikaflex 450) as a water-soluble adhesive, and a cationic ink fixing agent 10 Parts (trade name: Papiogen P-105, manufactured by Senka) were added and stirred, and water was further added to obtain a coating solution having a solid concentration of 25%.
<Formation of recording layer>
The obtained coating solution was applied on one side of the support with an air knife coater so that the dry coating amount was 10 g / m ^2, and dried with hot air using an air dryer.

  In Example 1, the amount of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison), which is an inorganic pigment that has not been deactivated, is 80 parts, The blending amount of synthetic amorphous silica (trade name: Nipgel AZ360, manufactured by Tosoh Silica Co., Ltd.), which is an inorganic pigment with an average particle size of 3.5 μm, was changed to 20 parts.

  In Example 1, the amount of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison), which is an inorganic pigment that has not been deactivated, is 20 parts. The blend amount of synthetic amorphous silica (trade name: Nipgel AZ360, manufactured by Tosoh Silica Co., Ltd.), which is an inorganic pigment with an average particle size of 3.5 μm, was changed to 80 parts.

  In Example 1, the amount of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison), which is an inorganic pigment that has not been deactivated, is 90 parts. The amount of synthetic amorphous silica (trade name: Nipgel AZ360, manufactured by Tosoh Silica Co., Ltd.), which is an inorganic pigment with an average particle size of 3.5 μm, was changed to 10 parts.

Comparative Example 1

  In Example 1, the inorganic pigment used was changed to 100 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison), which is an inorganic pigment that has not been deactivated, and has an average particle diameter of 7 μm.

Comparative Example 2

  In Example 1, 40 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 7 μm, which is an inorganic pigment that has not been subjected to a deactivation treatment, is used as the inorganic pigment to be used. Was changed to 60 parts of aluminum hydroxide (trade name: Hygielite H-42M, Showa Denko KK) of 2.0% or less and 98%.

Comparative Example 3

  In Example 1, 80 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 7 μm, which is an inorganic pigment that has not been deactivated, is used as the inorganic pigment to be used. Of which is 2.0 μm or less was changed to 20 parts of 98% aluminum hydroxide (trade name: Heidilite H-42M, Showa Denko KK).

Comparative Example 4

  In Example 1, 40 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 7 μm, which is an inorganic pigment that has not been deactivated, is used as the inorganic pigment to be used Of the baked clay (trade name: Ansilex 93, manufactured by BASF) having a particle size of 0.5 μm or less was changed to 86 parts.

Comparative Example 5

  In Example 1, 80 parts of synthetic amorphous silica (trade name: Silojet P407, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 7 μm, which is an inorganic pigment that has not been deactivated, is used as the inorganic pigment to be used. Of the baked clay (trade name: Ansilex 93, manufactured by BASF) having a particle size of 0.5 μm or less was changed to 86 parts.

<Discoloration evaluation 1>
The discoloration test of the obtained sample was performed as follows.
First, a 1% by weight solution in which 4,4-methylenebis-2,6-di-tert-butylphenol was dissolved in isopropanol was prepared. 20 μL of the solution was dropped onto the coated surface with a microsyringe. Thereafter, the sample was stored so as not to be exposed to light under the conditions of 23 ° C.-50% RH and drying conditions of 90 ° C., and the hue of the dripping part and the non-dropping part was measured with a color difference meter (trade name: trade name: CR-300, manufactured by Minolta). From the results, ΔE was calculated according to the following defining formula.
ΔE = √ ((L−L *) 2+ (a−a *) 2+ (b−b *) 2)
L, a, b: Dripping part Hue L *, a *, b *: Non-dropping part Hue That is, the smaller the ΔE, the smaller the hue change and the less the color change.

<Discoloration evaluation 2>
The discoloration test of the obtained sample was performed as follows.
A cellophane tape (trade name: CT-15, manufactured by Nichiban Co., Ltd.) is applied to one side of a copy paper (trade name: Maricopy, 64 g / m ² , manufactured by Hokuetsu Kishu Paper Co., Ltd.), and the obtained sample is applied to the other side The copy paper and the sample were placed in contact with each other so that the recording surface was in contact with each other, and stored for 24 hours under dry conditions at 70 ° C. Since the adhesive component of the cellophane tape affixed to the copy paper was transferred to the recording surface of the sample obtained by passing through the copy paper, the discoloration due to the transfer was visually confirmed and evaluated.
Judgment criteria:
A: Very good (the degree of discoloration is very small)
B: Good (less discoloration, practical range)
C: Slightly defective (the degree of discoloration is slightly large)
D: Defect (the degree of discoloration is large)

<Inkjet printing suitability>
The obtained sample was printed with an ink jet printer (trade name: PM-A900, manufactured by EPSON), and the applicability of the ink jet was evaluated by visually evaluating the bleeding of the image area and the uniformity of the solid area.
Judgment criteria:
A: Very good (both ink bleeding and solid uniformity are good)
B: Good (There is a slight problem with either ink bleeding or solid uniformity,
(Practical range)
C: Slightly poor (Both ink bleeding and solid part uniformity are poor)
D: Defect (Both ink bleeding and solid uniformity are both poor)

  The results of the physical property evaluation of the ink jet recording sheets obtained in the examples and comparative examples are shown in FIG. As is clear from the results of FIG. 1, the ink jet recording sheets obtained in Examples 1 to 4 according to the present invention have little discoloration, and the ink jet suitability is comparable to the conventional products. It was.

  On the other hand, none of the ink jet recording sheets obtained in Comparative Examples 1 to 4 was sufficiently inferior in discoloration prevention ability, and was particularly inferior in the results of discoloration experiments at high temperatures.

  According to the ink jet recording sheet of the present invention, there can be obtained an ink jet recording sheet that does not deteriorate ink jet printing quality, has little discoloration with time, and has an effect of suppressing discoloration of ink.

Claims (7)

A sheet-like support mainly composed of pulp;
And a recording layer formed on one side or both sides of the sheet-like support and coated with a coating liquid containing a porous fine-particle inorganic pigment, a water-soluble adhesive, and a cationic ink fixing agent. and wherein 10 to 80 parts by weight of the porous particulate inorganic pigment 100 parts by weight, the surface contributes surface active discoloration of the recording layer by being coated with various waxes is deactivated porous Is a fine particle inorganic pigment,
An ink jet recording sheet characterized by the above.   The inkjet recording sheet according to claim 1, wherein the porous fine-particle inorganic pigment includes silica, alumina, magnesia, titania, or apatite.   2. The inkjet recording sheet according to claim 1, wherein the amount of the porous particulate inorganic pigment is in the range of 200 to 334 parts by mass with respect to 100 parts by mass of the water-soluble adhesive. .   2. The inkjet recording according to claim 1, wherein the amount of the cationic ink fixing agent is in the range of 5 to 30 parts by mass with respect to 100 parts by mass of the porous particulate inorganic pigment. Sheet. ^2. The ink jet recording sheet according to claim 1, wherein the coating amount of the coating liquid is in a range of 5 to ²⁰ g / m < ² > per side in a dry state. The porous fine particle inorganic pigment whose surface activity contributing to the discoloration is deactivated is 20 to 60 parts by mass out of 100 parts by mass of the total fine particle inorganic pigment. Inkjet recording sheet. 2. The inkjet according to claim 1, wherein the porous particulate inorganic pigment whose surface activity contributing to discoloration is deactivated is particulate silica whose surface is coated with various waxes. Recording sheet.

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