JP2018138370A - Inkjet recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording paper that has a soft resilience, a light feeling of weight, and a high print density.SOLUTION: The present invention provides an inkjet recording paper free from a coating layer containing an inorganic pigment. The inkjet recording paper contains an ink fixer and a bulking agent. The ink fixer is a cationic polymer, and has a Stockigt size degree of 20 seconds or less.SELECTED DRAWING: None

Description

  The present invention relates to an inkjet recording paper. In particular, the present invention relates to an ink jet recording paper that can be suitably used as a book paper.

  The ink jet recording system is a system in which ink droplets are ejected and deposited on recording paper to form dots and recording is performed. In recent years, recording with high print quality has become possible due to technological advances in ink jet printers, inks, and recording media.

  Inkjet printer technology has been used not only in personal printers used at home, but also in fields such as commercial printing in which variable information is digitized and printed at high speed. That is, in recent years, in the field of commercial printing, a so-called on-demand printing method is being introduced, and many ink jet printers adopting the on-demand printing method have also appeared. This on-demand printing method is suitable for printing a small number of copies because information can be directly printed on a medium such as paper without making a plate.

  In recent years, the on-demand printing method has also been adopted in the book manufacturing field (text, comics, literary works, etc.). As book paper, paper that is soft and lightweight is used from the viewpoint of ease of turning the paper. The “strain” of paper here refers to the property that paper supports its own weight, that is, resistance when bending force is applied to the paper. For example, it is also called “stiffness” or “rigidity”. is there. As the paper used as the book paper, for example, it is preferable that the paper does not easily stand up when the book is opened. Therefore, as the book paper, a paper with low (soft) stiffness is preferable. Ink-jet printers are also being introduced in on-demand printing in the book manufacturing field. As paper that can be used for this commercial inkjet printer, there are coated paper type paper having a coating layer containing an inorganic pigment, and non-coated paper type paper not having the coating layer. However, it is a non-coated paper type that does not have a coating layer containing an inorganic pigment from the viewpoint of ease of turning the paper when used as book paper, lightness, low reflection of light, and low eye burden. Paper is often used. On the other hand, as paper used in conventional offset printing, coated paper is generally used. However, there is no paper having the characteristics of non-coated paper that is easy to turn, soft, and lightweight. . In addition, when printing on an uncoated paper type book paper used in conventional offset printing with an ink jet printer, the ink fixability is poor, so ink is blurred and printing unevenness occurs, which is not practical. There was a problem. Furthermore, since the paper having a light feeling has a high specific volume and a porous surface, the ink tends to sink into the inside of the paper, so that there is a problem that the print density is low.

  As a paper suitable for a commercial ink jet printer, a printing paper using calcium carbonate having an oil absorption amount in a specific range for the coating layer of the ink jet recording paper in order to improve ink absorbability (for example, patent document) 1) and the like have been proposed. However, it is a coated paper type paper, and can be easily turned like a book paper, and can not have the characteristics of a non-coated paper that is soft and light, and is suitable as a book paper. Difficult to use for In addition, as a so-called non-coated paper type paper, an inkjet paper (for example, see Patent Document 2) in which the ink absorption is improved by limiting the type of starch that is a paper strength agent has been proposed. Despite the non-coated paper type paper, the paper is hard and heavy and difficult to use as a book paper commercially. Therefore, there is no optimum ink jet paper that is compatible with a commercial ink jet printer and that is soft and lightweight like conventional book paper.

JP 2008-238612 A JP 11-334199 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording paper having a high print density while maintaining the advantages of non-coated paper that is soft and light. In other words, it is a non-coated paper type paper, but has a good ink jet recording ability that can be applied to a commercial high speed ink jet printing machine (for example, a printing machine with a printing speed exceeding 50 m / min). An ink jet recording paper that can be suitably used as the above is provided.

  The ink jet recording paper according to the present invention is an uncoated paper type ink jet recording paper that does not have a coating layer containing an inorganic pigment, and contains an ink fixing agent and a bulking agent, and the ink fixing agent is cationic. It is a polymer and is characterized in that it has a paper sizing degree of 20 seconds or less.

The ink jet recording paper according to the present invention preferably has a specific volume (specific volume) of 1.30 to 1.60 cm ³ / g from the viewpoint of light weight of the paper and print density. Higher alcohol or polyhydric alcohol and fatty acid ester compound, polyoxyalkylene adduct of polyhydric alcohol and fatty acid ester compound, fatty acid polyamidoamine, saturated fatty acid polyamidopolyamine epichlorohydrin reaction product, higher alcohol ethylene It is preferable that any one or more selected from an oxide adduct, a propylene oxide adduct of a higher alcohol, a polyoxyalkylene adduct of a higher alcohol or a higher fatty acid, a polyoxyalkylene adduct of a higher fatty acid ester is used, Further, in some cases, it is preferable to further contain 0.02 to 0.15 part of a sizing agent with respect to 100 parts by mass of pulp.

  According to the present invention, it is possible to provide an ink jet recording paper which has good ink jet recording suitability, is soft and has a light feeling, and does not have a coating layer containing an inorganic pigment. Furthermore, the ink jet paper according to the present invention is suitable for use as book paper, and can be used for commercial high speed ink jet printers. Therefore, it is suitable as a book paper applied to the on-demand printing method.

  Next, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  The book paper for inkjet recording of the present invention contains pulp as a main component. Examples of the pulp used here include chemical pulp such as LBKP (hardwood bleached kraft pulp), NBKP (softwood bleached kraft pulp), GP (crushed wood pulp), PGW (pressurized groundwood pulp), RMP (refiner mechanical pulp), TMP (thermomechanical pulp), CTMP (chemithermomechanical pulp), CMP (chemimechanical pulp), mechanical pulp such as CGP (chemiground pulp), wood pulp such as DIP (deinked pulp) and kenaf, bagasse, bamboo, Non-wood pulp such as cotton. These can be used alone or in admixture at any ratio. For example, it is preferable that LBKP is mainly used and LBKP is included at 80 to 100% by mass with respect to the total mass of the pulp. Among these, it is also preferable to use chemical pulp as a main component from the viewpoint of ink jet recording suitability. Furthermore, it is desirable to blend ECF (Elemental Chlorine Free) pulp or TCF (Totally Chlorine Free) pulp with less environmental burden. Moreover, it is preferable that the pulp which comprises the base paper which concerns on this invention is made into the paper stock which has a suitable beating degree as an inkjet printing paper. Suitable beating degree is, for example, Canadian standard freeness (freeness) (JIS P 8121: 1995 “pulp freeness test method”), 350 to 650 ml CSF, for example, 350 to 500 ml CSF. From the viewpoint of printing density, 350 to 485 ml CSF is preferable. More preferably, it is 360-480 ml CSF. When the freeness is less than 350 ml CSF, the paper strain becomes hard, which is not preferable as book paper. Also, when the freeness exceeds 485 ml CSF, the print density tends to decrease. In the paper, known fillers such as heavy calcium carbonate, light calcium carbonate, magnesium carbonate, titanium oxide, synthetic silica, alumina, talc, calcined kaolin clay, kaolin clay, bentonite, zeolite, aluminum hydroxide, zinc oxide, Various papermaking chemicals such as known paper strength agents, sulfuric acid bands, yield improvers, dyes and fluorescent dyes may be used as appropriate. In the present invention, as the filler, it is preferable to contain light calcium carbonate from the viewpoint of bulkiness effect and prevention of ink bleeding, and it is added so that the ash content of the paper after paper making becomes 10 to 30% by mass. is there. More preferably, it is 12-28 mass%. More preferably, it is 14 to 26%. When the ash content is less than 10% by mass, the paper is hard and is not preferable as a book paper. Further, when the ash content exceeds 30% by mass, the printing density tends to decrease.

  The preparation method, blending method, and addition method of each papermaking chemical for each paper stock are not particularly limited as long as the effects of the present invention are not impaired. In addition, it is possible to make paper using a well-known paper machine such as a circular net paper machine, a long net paper machine, or a twin wire paper machine using a paper material. . Furthermore, as long as the effects of the present invention are not impaired, waste paper pulp can be blended as pulp. Furthermore, a known water-soluble polymer such as starch or polyacrylamide can be applied with a known size press or gate roll coater.

In the present invention, it is essential that the paper contains a cationic polymer as an ink fixing agent and a bulking agent. As a method for incorporating the cationic polymer and the bulking agent as the ink fixing agent into the paper, they may be added to the paper stock, or may be applied to the paper web with a size press or a gate roll coater. In the case of coating, an ink fixing agent and / or a bulking agent may be added to the size press solution or the gate roll coater coating solution. Among these methods, the bulking agent is preferably added to the stock because it is easy to adjust the specific volume appropriately. In addition, since it is easy to obtain optimum ink fixing properties, the cationic polymer is preferably added to the size press solution or the gate roll coater coating solution. For example, a size press solution containing 1 to 7% by mass of the cationic polymer as an ink fixing agent to a size press solution containing 2 to 7% by mass of starch such as oxidized starch as a size press solution is dried on both sides or one side. A coating amount of 1.0 to 3.0 g / m ² can be applied per both sides.

Examples of the bulking agent used in the present invention include higher alcohols or polyhydric alcohol and fatty acid ester compounds, polyoxyalkylene adducts of polyhydric alcohol and fatty acid ester compounds, fatty acid polyamidoamines, and epichloroforms of saturated fatty acid polyamidopolyamines. Known bulking agents such as hydrin reactant, higher alcohol ethylene oxide adduct, higher alcohol propylene oxide adduct, higher alcohol or higher fatty acid polyoxyalkylene adduct, higher fatty acid ester polyoxyalkylene adduct, etc. It is possible to use. These may be used alone or in combination of two or more. In this embodiment, it is preferable that a bulking agent contains 0.01-2.0 mass parts with respect to 100 mass parts of pulp. For example, 0.05 to 1.5 parts by mass and 0.2 to 0.9 parts by mass are contained. When the content of the bulking agent is less than 0.01 parts by mass, the bulking effect cannot be obtained satisfactorily, and the specific volume of the inkjet paper is lowered. When the amount exceeds 2.0 parts by mass, the bulk density effect can be obtained, but the printing density may decrease. More preferably, the bulking agent is contained in an amount of 0.02 to 1.5 parts by mass with respect to 100 parts by mass of the pulp. More preferably, the bulking agent is contained in an amount of 0.05 to 0.9 parts by mass, for example, 0.05 to 0.6 parts by mass with respect to 100 parts by mass of the pulp. Moreover, in this invention, it is preferable to adjust the specific volume of an inkjet recording paper to 1.30-1.60cm < ³ > / g by containing the said bulking agent. If the specific volume is less than 1.30 cm ³ / g, the book paper may become stiff, and if the specific volume exceeds 1.60 cm ³ / g, there are too many voids in the paper and printing Concentration may decrease. In the present invention, the specific volume of the ink jet recording paper is more preferably 1.35 to 1.55 cm ³ / g. The specific volume (cm ³ / g) referred to in the present invention is a numerical value obtained by dividing the thickness (μm) of the inkjet recording paper by the basis weight (g / m ² ).

  In the present invention, it is essential that the degree of sizing of the inkjet recording paper is 20 seconds or less. When the Steecht sizing degree exceeds 20 seconds, the print density decreases. Preferably it is 15 seconds or less. More preferably, it is 13 seconds or less. Although a minimum is not limited, It is preferable that it is 1 second or more. The degree of sizing human sizing can be adjusted by the presence or absence of a sizing agent and its content. Usually, the print density tends to be higher as the ink easily stays on the surface of the paper, but the reverse tendency is exhibited in the ink jet recording paper of the present invention. The reason for this is not clear, but is presumed as follows. That is, the ink jet recording paper of the present invention contains a bulking agent, has a relatively high specific volume, and has a structure in which the paper surface is porous and has a large gap. In general, a high sizing degree makes it difficult for the pulp fibers to absorb the ink, so the ink tends to stay on the paper surface. However, the pulp fibers absorb the ink in a paper having a porous surface and a large gap. When it becomes difficult, the ink easily enters the gaps on the surface of the paper, and as a result, the ink does not stay on the surface of the paper but easily falls inside. Therefore, in the present invention, the value of the paper sizing degree is adjusted to a relatively small value so that the pulp fibers on the paper surface can easily absorb ink. As a result, it is assumed that the ink is more easily fixed on the pulp fiber on the paper surface, and the printing density is improved. Note that these assumptions may seem to contradict the principle of measuring the Steecht sizing degree, but considering that the droplets of ink ejected by inkjet recording are relatively small, they are not necessarily in conflict. It seems that it cannot be said to be the principle to do. Further, the method for measuring the degree of Steecht sizing is in accordance with JIS P8122: 2004 “Paper and paperboard—Sizing test method—Steecht method”.

In the present invention, the ink jet recording paper further contains a cationic polymer as an ink fixing agent. By containing the cationic polymer, it is possible to further suppress ink bleeding and printing unevenness even though it is an inkjet recording paper containing a bulking agent and having a high specific volume and no coating layer. Examples of the cationic polymer as the ink fixing agent used in the present invention include polyethyleneimine, epichlorohydrin-modified polyalkylamine, polyamine, polyamine polyamide epichlorohydrin, dimethylamine ammonia epichlorohydrin, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide. , Polydimethylaminoethyl methacrylate hydrochloride, polyvinylpyridium halide, cationic polyacrylamide, cationic polystyrene copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride sulfur dioxide copolymer, diallyldimethylammonium chloride amide copolymer , Dicyandiamide formalin polycondensate, dicyandia Dodiethylenetriamine polycondensate, polyallylamine, polydiallylamine, polyallylamine hydrochloride, polyacrylamide resin, polyamide epoxy resin, melamine resin acid colloid, urea resin, cation-modified polyvinyl alcohol, amino acid type amphoteric surfactant, betaine type compound , Polyamidine compounds, other quaternary ammonium salts, and cation-modified polyurethane resins. These may be used alone or in combination of two or more. In the present embodiment, the content into the paper of the cationic polymer is preferably 0.1 to 5.0 g / ^{m 2,} more preferably be 0.2~4.0g / ^{m 2} For example, it is 0.2-1.8 g / m < ² >. When the content of the cationic polymer is less than 0.1 g / m ² , the ink tends to bleed, and when it exceeds 5.0 g / m ² , uneven printing tends to occur.

The inkjet paper according to the present invention preferably has a specific volume (specific volume) of 1.30 to 1.60 cm ³ / g from the viewpoint of the light weight of the paper. Further, the basis weight is preferably 50 to 100 g / m ² from the viewpoint of lightness and strain. More preferably, it is 60-95 g / m < ² >. When the basis weight is less than 50 g / m ² , show-through or show-through after ink jet printing occurs, and when it exceeds 100 g / m ² , the lightness is inferior.

  Further, in the present invention, an appropriate amount of sizing agent may be contained in order to adjust the squeecht sizing degree of the ink jet recording paper to 20 seconds or less. The content of the sizing agent internally added to the paper stock is preferably 0 part to 0.15 part with respect to 100 parts of pulp, for example, 0.02 to 0.15 part, and more preferably 0 part. ~ 0.13 parts. The sizing agent used here is a known sizing agent such as alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), styrene / acrylic copolymer, styrene / methacrylic copolymer, rosin sizing agent, and the like. . These may be used alone or in combination of two or more. Further, as long as the effects of the present invention are not inhibited, a combination with a cationic sizing agent, a nonionic sizing agent, and an anionic sizing agent is possible. Furthermore, from the viewpoint of printing density, it is preferable not to add the surface sizing agent to a size press solution or a gate roll coater coating solution applied by a size press or a gate roll coater. That is, the inkjet recording paper of the present invention may not contain a sizing agent.

  In the production method of the present invention, the pulp is beaten to a Canadian standard freeness of 350 to 485 ml CSF, and as a bulking agent, for example, fatty acid polyamidoamine is 0.01 to 100 parts by mass of the pulp. 2.0 parts by weight, as an internally added sizing agent, for example, after making a paper stock containing 0 to 0.15 parts by weight of alkenyl succinic anhydride (ASA) with a long paper machine, It is preferable to apply an aqueous solution containing starch and a cationic polymer to the web and then dry it. In the present invention, a calendar process such as a machine calendar, a soft calendar, and a super calendar can be performed and a smoothing process can also be performed, and the final size of the ink jet recording paper is set to 20 seconds or less. In addition, a known wet paper strength agent such as urea formaldehyde resin, melamine formaldehyde resin, polyamide polyamine epichlorohydrin, polyvinylamine, etc. can be added to the stock.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “parts” and “%” represent “parts by mass” and “mass%”, respectively, unless otherwise specified. The number of added parts is a value in terms of solid content.

Example 1
0.25 parts starch (Neotac 30T: manufactured by Nippon Food Processing Co., Ltd.), nonionic rosin sizing agent (Size Pine NT-78: Arakawa Chemical Industries, Ltd.) per 100 parts of hardwood bleached kraft pulp (Canada standard freeness 470 ml CSF) 0.10 parts, light calcium carbonate (Tamapearl TP-121S, manufactured by Okutama Kogyo Co., Ltd.), the amount of which was adjusted so that the ash content of the paper after paper making was 18%, and fatty acid polyamidoamine (masked as a bulking agent) 0.4 parts of K300 (manufactured by Nikka Chemical Co., Ltd.) was blended to obtain a paper material. Using this paper stock, paper was made with a long paper machine to obtain a paper sheet (single-layer paper making). Then, 5% oxidized starch (MS # 3800: manufactured by Nippon Food & Chemical Co., Ltd.) and 3% polyamine resin (DK6853: manufactured by Seiko PMC) as an ink fixing agent were mixed as a size press solution. The aqueous solution was applied to both sides of the paper web with a size press so that the dry coating amount was 2.0 g / m ² per both sides, and dried with a cylinder dryer, and the basis weight was 64 g / m ² and the thickness was 96 μm (specific volume). 1.50 cm ³ / g) inkjet recording paper was produced. At this time, the Steecht sizing degree was 10 seconds.

(Example 2)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the addition amount of fatty acid polyamidoamine (Maskote K300: manufactured by Nikka Chemical Co., Ltd.), which is a bulking agent, was changed to 0.05 parts by mass. The basis weight of the obtained paper was 64 g / m ² and the thickness was 83 μm (specific volume 1.30 cm ³ / g). At this time, the Steecht sizing degree was 9 seconds.

(Example 3)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the addition amount of fatty acid polyamidoamine (Mascut K300: manufactured by Nikka Chemical Co., Ltd.), which is a bulking agent, was changed to 0.8 parts by mass. The obtained paper had a basis weight of 64 g / m ² and a thickness of 102 μm (specific volume 1.60 cm ³ / g). At this time, the Steecht sizing degree was 11 seconds.

(Example 4)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the addition amount of fatty acid polyamidoamine (Maskote K300: manufactured by Nikka Chemical Co., Ltd.), which is a bulking agent, was changed to 0.50 parts by mass. The obtained paper had a basis weight of 64 g / m ² and a thickness of 99 μm (specific volume 1.55 cm ³ / g). At this time, the Steecht sizing degree was 10 seconds.

(Example 5)
Inkjet recording paper was prepared in the same manner as in Example 1, except that the amount of nonionic rosin sizing agent (Size Pine NT-78: manufactured by Arakawa Chemical Industries, Ltd.) was changed to 0.15 part. The obtained paper had a basis weight of 64 g / m ² and a thickness of 96 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 15 seconds.

(Example 6)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the amount of nonionic rosin sizing agent (Size Pine NT-78: manufactured by Arakawa Chemical Industries, Ltd.) was changed to 0.02 part. The obtained paper had a basis weight of 64 g / m ² and a thickness of 96 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 2 seconds.

(Example 7)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the amount of nonionic rosin sizing agent (Size Pine NT-78: manufactured by Arakawa Chemical Industries, Ltd.) was changed to 0 part. The obtained paper had a basis weight of 64 g / m ² and a thickness of 96 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 0.4 seconds.

(Example 8)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the basis weight of the paper was adjusted to 100 g / m ² in Example 1. The obtained paper had a basis weight of 100 g / m ² and a thickness of 150 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 20 seconds.

Example 9
An ink jet recording paper was prepared in the same manner as in Example 1 except that the basis weight of the paper was adjusted to 90 g / m ² in Example 1. The basis weight of the obtained paper was 90 g / m ² and the thickness was 135 μm (specific volume 1.50 cm ³ / g). At this time, the Steecht sizing degree was 15 seconds.

(Example 10)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 400 ml CSF. The obtained paper had a basis weight of 64 g / m ² and a thickness of 93 μm (specific volume: 1.45 cm ³ / g). At this time, the Steecht sizing degree was 10 seconds.

(Comparative Example 1)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the amount of nonionic rosin sizing agent (Size Pine NT-78: manufactured by Arakawa Chemical Industries, Ltd.) was changed to 0.40 part. The obtained paper had a basis weight of 64 g / m ² and a thickness of 96 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 40 seconds.

(Comparative Example 2)
Inkjet recording paper was prepared in the same manner as in Example 1 except that polyamine resin (DK6853: manufactured by Seiko PMC) as a cationic polymer as an ink fixing agent was not added. The obtained paper had a basis weight of 64 g / m ² and a thickness of 96 μm (specific volume: 1.50 cm ³ / g). At this time, the Steecht sizing degree was 10 seconds.

The obtained inkjet recording paper was subjected to the following evaluation, and the results are shown in Table 1. The specific volume (cm ³ / g) referred to in the present invention is a numerical value obtained by dividing the thickness (μm) of the inkjet recording paper by the basis weight (g / m ² ).

(1) Measurement of squeecht size:
The degree of sizing of paper was measured according to JIS P8122: 2004 “Paper and paperboard—Testing method of sizing—Steechtman method”.

(2) Character bleeding:
Using a commercial inkjet printer (HP T300 Color InkjetPress: Hewlett Packard), characters were printed on the obtained inkjet recording paper in black, cyan, magenta, and yellow at a printing speed of 122 m / min. The degree of bleeding of the printed characters was judged by visual observation and evaluated in the following four stages.
(Double-circle): A character does not blur at all and it can be used practically.
○: Characters are slightly blurred but practical.
Δ: Characters are blurred and impractical.
X: Characters are significantly blurred and impractical.

(3) Print density:
Using a commercial inkjet printer (HP T300 Color InkjetPress: manufactured by Hewlett Packard), solids were printed on the obtained inkjet recording paper in black, cyan, magenta, and yellow at a printing speed of 122 m / min. The print density of the printed solid part was visually determined and evaluated in the following four stages.
A: The print density is very high, the color developability is extremely excellent, and it can be practically used.
○: High print density, excellent color development, and practical use.
Δ: Print density is low, color developability is inferior, and impractical.
X: Print density is extremely low, color developability is extremely inferior, and impractical.

  As is clear from Table 1, the ink jet recording papers obtained in Examples 1 to 10 were excellent in ink jet recording suitability. In addition, any of the ink jet recording papers is easy to turn, has a soft squeeze, and feels lightweight, and is suitable for use as a book paper.

  On the other hand, the ink jet recording paper obtained in Comparative Example 1 had a remarkable decrease in print density because the Steecht degree exceeded 20 seconds. Further, since the ink jet recording paper obtained in Comparative Example 2 did not contain a cationic polymer, the print density was remarkably lowered, and the letter bleeding was not very good.

Claims (5)

  An ink jet recording paper having no coating layer containing an inorganic pigment, comprising an ink fixing agent and a bulking agent, the ink fixing agent being a cationic polymer, and a Steecht sizing degree of 20 seconds or less An inkjet recording paper characterized by the above. 2. The inkjet recording paper according to claim 1, wherein a specific volume of the inkjet recording paper is 1.30 to 1.60 cm ³ / g.   Higher alcohol or polyhydric alcohol and fatty acid ester compound, polyoxyalkylene adduct of polyhydric alcohol and fatty acid ester compound, fatty acid polyamidoamine, saturated fatty acid polyamidopolyamine epichlorohydrin reaction product, higher alcohol ethylene One or more selected from an oxide adduct, a propylene oxide adduct of a higher alcohol, a polyoxyalkylene adduct of a higher alcohol or a higher fatty acid, or a polyoxyalkylene adduct of a higher fatty acid ester is used. The inkjet recording paper according to claim 1 or 2.   The inkjet recording paper as described in any one of Claims 1-3 which further contains 0.02-0.15 part sizing agent with respect to 100 mass parts of pulp.   The inkjet recording paper according to any one of claims 1 to 4, which is a book paper for printing by an on-demand printing method.