JP2019147389A - Ink jet recording paper - Google Patents

Abstract

To provide ink jet recording paper which has good ink jet recording suitability and can be suitably used as book paper.SOLUTION: Ink jet recording paper having no coating layer containing an inorganic pigment, contains an ink fixing agent and a bulking agent, wherein the ink fixing agent is a cationic polymer, and wherein elongation in water in the lateral direction of the paper is 3.0% or less.SELECTED DRAWING: None

Description

  The present invention relates to an inkjet recording paper. In particular, the present invention relates to an inkjet 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. Paper that can be used for this commercial inkjet printing machine includes coated paper type paper having a coating layer containing an inorganic pigment, and non-coated paper type paper having no coating layer containing an inorganic pigment. Paper is present, but it is uncoated without a coating layer containing an inorganic pigment from the standpoints of ease of turning the paper when used as book paper, lightness, low light reflection, and low eye strain. In many cases, paper of the paper type is used. On the other hand, as paper used in conventional offset printing, coated paper is generally used, but uncoated paper that is easy to turn like non-coated paper, is soft and has a light weight feeling. There is no paper with features. 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. Further, for example, there is a problem that wrinkles are likely to occur in a portion where a large amount of ink has landed, such as a solid portion. If wrinkles are significant, improvement is difficult even if the printing conditions are adjusted.

  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)), etc., but it is a coated paper type paper that is easy to turn, like a conventional non-coated paper type book paper, is soft and has a light weight. Cannot be suitably used as book paper. 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. This is hard and heavy, and is difficult to use as book paper. Therefore, there is no suitable inkjet paper that is compatible with commercial inkjet printers 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 that is soft and lightweight, has good ink fixing properties, and does not easily bleed or cause printing unevenness. In particular, it is an object of the present invention to provide an ink jet recording paper that generates less wrinkles during ink jet printing as described above. In other words, it has non-coated paper type paper, but has ink jet recording suitability for commercial high speed ink jet printing machines (for example, printing machines with printing speeds exceeding 50 m / min), and is suitable as book paper. An ink jet recording paper that can be used in the present invention is provided.

The ink jet recording paper according to the present invention is an ink jet recording paper that does not have a coating layer containing an inorganic pigment, contains an ink fixing agent and a bulking agent, and the ink fixing agent is a cationic polymer, Further, the underwater elongation in the transverse direction of the paper is 3.0% or less. Further, in order to give the paper a light feeling, the specific volume (specific volume) of the ink jet recording paper according to the present invention may be 1.25 to 2.00 cm ³ / g.

  Furthermore, the present invention provides a paper stock containing 350 to 485 ml CSF pulp and a fatty acid polyamidoamine as a bulking agent at a Canadian standard freeness (JIS P 8121: 1995 “Pulp Freeness Test Method”). The present invention relates to a method for producing an ink jet recording paper, comprising: making a paper sheet, obtaining a paper sheet, applying an aqueous solution containing a cationic polymer as an ink fixing agent to the paper sheet, and then drying. If it is the said method, the inkjet recording paper which can be used as book paper can be provided.

  According to the present invention, it is possible to provide an ink jet recording paper that is soft and has a light feeling, is less likely to bleed ink, and is less likely to cause printing unevenness. In particular, it is possible to provide an ink jet recording paper that generates less wrinkles during ink jet printing. Furthermore, the inkjet paper according to the present invention is suitable for inkjet recording that is compatible with commercial high-speed inkjet printers (for example, printers with printing speeds exceeding 50 m / min) while being uncoated paper type paper. And suitable for use as book paper.

  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. 350 to 485 ml CSF is preferable in order to make the elongation in water of the side of the paper 3.0% or less. 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. Further, when the freeness exceeds 485 ml CSF, the underwater elongation may be excessively large, and wrinkles are likely to occur during ink jet printing. 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, light calcium carbonate is preferable from the viewpoint of bulkiness effect and prevention of ink bleeding. In order to make the elongation in water of the side of the paper 3.0% or less, the preferable amount of filler is to add 10 to 30% by mass of the ash content of the paper after paper making. 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. Moreover, when the ash content exceeds 30% by mass, wrinkles are likely to occur during ink jet printing. 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 and a bulking agent as an ink fixing agent. As a method for inclusion in the paper, it may be added to the paper material, or may be added to a size press solution or a gate roll coater coating solution applied by a size press or a gate roll coater. The bulking agent is preferably added to the stock. It becomes easy to adjust the specific volume appropriately. Furthermore, the cationic polymer is preferably added to the size press solution or the gate roll coater coating solution. It is easy to obtain better ink fixability. For example, the cationic polymer can be added to a size press liquid containing 2 to 7% by mass of starch.

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. This is because it is easy to adjust the underwater elongation in the transverse direction of the paper to an appropriate range. If 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 ink jet recording paper is lowered. When the amount exceeds 2.0 parts by mass, the bulkiness effect is obtained, but the paper layer strength is lowered and it is easily broken. More preferably, the bulking agent is contained in an amount of 0.05 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 0.2 to 0.9 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 1.25-2.00 cm < ³ > / g by containing the said bulking agent. When the specific volume is less than 1.25 cm ³ / g, the strain tends to be hard and may be difficult to apply to book paper. When the specific volume exceeds 2.00 cm ³ / g, there are too many voids in the paper, and unevenness of the solid portion during ink jet printing tends to occur, and the strength of the paper layer is lowered and easily broken. In the present invention, the specific volume of the ink jet recording paper is more preferably 1.30 to 1.95 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 ink jet recording sheet has an underwater elongation of 3.0% or less after 5 minutes in the horizontal direction of the paper. When the elongation in water exceeds 3.0%, wrinkles occur during ink jet printing. Preferably it is 2.9% or less. More preferably, it is 2.8% or less. Further, the measuring method of the paper underwater elongation is JAPAN TAPPI No. 27 According to “Testing method for paper and board immersion rate” (measurement time is 5 minutes). The method for controlling the elongation in water in the direction of the transverse direction of the paper is not particularly limited, and a conventionally known method may be used. Since the elongation in water tends to increase as the paper becomes bulky, that is, the specific volume increases, the elongation in water can be controlled by adjusting the content of the above-described bulking agent in the inkjet recording paper of the present invention. can do. In addition, as described above, it is possible to control by Canadian standard freeness and ash content. Moreover, by including polyvinyl alcohol, the underwater elongation in the horizontal direction of the paper can be reduced. The polyvinyl alcohol is preferably polyvinyl alcohol having a saponification degree of 85 to 100 mol%. As a method for inclusion in paper, it may be added to the stock, or may be added to a size press solution or a gate roll coater coating solution applied by a size press or a gate roll coater. Preferably the content into the paper of the polyvinyl alcohol is 0.01 to 2.0 g / ^{m 2,} more preferably from 0.02~1.5g / ^{m 2.} By setting it as such a range, the underwater elongation of the horizontal direction of paper can be made small. In addition, when the content of polyvinyl alcohol is less than 0.01 g / m ^2, the effect of reducing the elongation in water is poor. On the other hand, if it exceeds 2.0 g / m ² , ink permeation into the paper is excessively suppressed, and problems relating to printing quality such as bleeding and unevenness tend to occur.

In the present invention, the ink jet recording paper further contains a cationic polymer as an ink fixing agent. By containing a cationic polymer, it is possible to further suppress ink bleeding and printing unevenness even though it is an inkjet recording paper that contains a bulking agent, has a high specific volume, and does not have a coating layer. Because. 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 at 0.2~4.0g / ^{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 1.25 to 2.00 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 60-90 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.

Furthermore, in the present invention, it is preferable to contain a cationic sizing agent in the inkjet recording paper. The ink jet recording paper of the present invention does not have a coating layer containing an inorganic pigment, has a relatively high specific volume, and may contain a bulking agent, and the ink easily soaks into the paper when printed by the ink jet recording method. It has become. However, by incorporating a cationic sizing agent, it is possible to prevent ink from penetrating into the paper. Examples of the cationic sizing agent used herein include known sizing agents such as alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), styrene / acrylic copolymer, styrene / methacrylic copolymer, and rosin sizing agent. In addition, it is preferable that the ionicity is cationic. These may be used alone or in combination of two or more. Since the ink is anionic, by containing a cationic sizing agent, it is possible to moderately improve ink fixability and suppress ink bleeding and printing unevenness while suppressing ink penetration into the paper. It becomes possible. In the present invention, the content of the cationic sizing agent in the paper is preferably 0.001 to 0.1 g / m ² , more preferably 0.005 to 0.05 g / m ² . When the content of the cationic sizing agent is less than 0.001 g / m ² , the ink can not be sufficiently soaked into the paper, and the ink may be spread. If it exceeds 0.1 g / m ² , ink soaking into the paper is excessively suppressed, and printing unevenness is likely to occur. Further, as long as the effects of the present invention are not inhibited, a combination with a nonionic sizing agent and an anionic sizing agent is also possible.

  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. It is preferable to make a paper stock containing 2.0 parts by mass with a long paper machine to obtain a paper stock, and then apply an aqueous solution containing starch and a cationic polymer to the paper stock and then dry it. In the present invention, it is possible to perform a smoothing process by performing a calendar process such as a machine calendar, a soft calendar, a super calendar, etc., and the ink jet recording paper as the final product has an underwater elongation of 3 in the horizontal direction of the paper. 0.0% or less.

  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
For 100 parts hardwood bleached kraft pulp (Canadian standard freeness 420 ml CSF), 0.3 part starch (Neotac 30T: manufactured by Nippon Food Processing Co., Ltd.), 0.2 part nonionic rosin sizing agent (CC167: Seiko PMC), Light calcium carbonate (PC-700: manufactured by Shiraishi Kogyo Co., Ltd.), the amount of which was adjusted so that the ash content of the paper after papermaking was 18%, and fatty acid polyamidoamine as a bulking agent (Maskate K300: manufactured by Nikka Chemical Co., Ltd.) 0.5 part was blended to obtain a paper stock. Using this paper stock, paper was made with a long paper machine to obtain a paper sheet (single-layer paper making). Thereafter, as a size press solution, 2% oxidized starch (MS # 3800: manufactured by Nippon Shokuhin Kako Co., Ltd.), 3% polyamine resin (DK6810: manufactured by Seiko PMC) as a cationic polymer, cationic An aqueous solution in which 0.05% of a cationic alkyl ketene dimer (SE2360: manufactured by Seiko PMC), which is a sizing agent, is mixed so that the dry coating amount is 2.0 g / m ^{2 on} both sides of the paper sheet. The ink was applied with a size press and dried with a cylinder dryer to prepare an inkjet recording paper having a basis weight of 60 g / m ² and a thickness of 90 μm (specific volume: 1.50 cm ³ / g).

(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 60 g / m ² and the thickness was 76 μm (specific volume 1.27 cm ³ / g).

(Example 3)
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 2.0 parts by mass. The obtained paper had a basis weight of 60 g / m ² and a thickness of 120 μm (specific volume: 2.00 cm ³ / g).

(Example 4)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 485 ml CSF. The obtained paper had a basis weight of 60 g / m ² and a thickness of 96 μm (specific volume 1.60 cm ³ / g).

(Example 5)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 350 ml CSF. The basis weight of the obtained paper was 60 g / m ² and the thickness was 78 μm (specific volume 1.30 cm ³ / g).

(Example 6)
In Example 1, an ink jet recording paper was prepared in the same manner as in Example 1 except that the amount of light calcium carbonate (PC-700: manufactured by Shiroishi Kogyo Co., Ltd.) was adjusted so that the ash content of the paper after papermaking was 10%. Produced. The obtained paper had a basis weight of 60 g / m ² and a thickness of 84 μm (specific volume: 1.40 cm ³ / g).

(Example 7)
In Example 1, an ink jet recording paper was prepared in the same manner as in Example 1 except that the amount of light calcium carbonate (PC-700: manufactured by Shiroishi Kogyo Co., Ltd.) was adjusted so that the ash content of the paper after papermaking was 30%. Produced. The obtained paper had a basis weight of 60 g / m ² and a thickness of 96 μm (specific volume 1.60 cm ³ / g).

(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).

Example 9
In Example 1, an ink jet recording paper was prepared in the same manner as in Example 1 except that the amount of light calcium carbonate (PC-700: manufactured by Shiroishi Kogyo Co., Ltd.) was adjusted so that the ash content of the paper after papermaking was 12%. Produced. The obtained paper had a basis weight of 60 g / m ² and a thickness of 87 μm (specific volume: 1.45 cm ³ / g).

(Example 10)
In Example 1, an ink jet recording paper was prepared in the same manner as in Example 1 except that the amount of light calcium carbonate (PC-700: manufactured by Shiroishi Kogyo Co., Ltd.) was adjusted so that the ash content of the paper after papermaking was 28%. Produced. The basis weight of the obtained paper was 60 g / m ² , and the thickness was 93 μm (specific volume 1.55 cm ³ / g).

(Example 11)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 460 ml CSF. The basis weight of the obtained paper was 60 g / m ² , and the thickness was 93 μm (specific volume 1.55 cm ³ / g).

(Example 12)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 370 ml CSF. The obtained paper had a basis weight of 60 g / m ² and a thickness of 81 μm (specific volume: 1.35 cm ³ / g).

(Example 13)
In Example 1, as a size press solution, 2% oxidized starch (MS # 3800: manufactured by Nippon Shokuhin Kako Co., Ltd.), 3% polyamine resin (DK6810: manufactured by Seiko PMC) as a cationic polymer as an ink fixing agent Except that an aqueous solution of a cationic alkyl ketene dimer (SE2360: manufactured by Seiko PMC) 0.05% and a polyvinyl alcohol (PVA117: manufactured by Kuraray) 1% having a saponification degree of 99 mol%, which is a cationic sizing agent, was used. Inkjet recording paper was prepared in the same manner as in Example 1. The basis weight of the obtained paper was 60 g / m ² and thickness 90 μm (specific volume 1.50 cm ³ / g).

(Example 14)
In Example 3, as a size press solution, 2% oxidized starch (MS # 3800: manufactured by Nippon Shokuhin Kako Co., Ltd.), 3% of polyamine resin (DK6810: manufactured by Seiko PMC) as a cationic polymer as an ink fixing agent Except that an aqueous solution of a cationic alkyl ketene dimer (SE2360: manufactured by Seiko PMC) 0.05% and a polyvinyl alcohol (PVA117: manufactured by Kuraray) 1% having a saponification degree of 99 mol%, which is a cationic sizing agent, was used. Inkjet recording paper was prepared in the same manner as Example 3. The basis weight of the obtained paper was 60 g / m ² and thickness 120 μm (specific volume 2.00 cm ³ / g).

(Example 15)
In Example 10, as a size press solution, 2% oxidized starch (MS # 3800: manufactured by Nippon Shokuhin Kako Co., Ltd.), 3% polyamine resin (DK6810: manufactured by Seiko PMC) as a cationic polymer as an ink fixing agent Except that an aqueous solution of a cationic alkyl ketene dimer (SE2360: manufactured by Seiko PMC) 0.05% and a polyvinyl alcohol (PVA117: manufactured by Kuraray) 1% having a saponification degree of 99 mol%, which is a cationic sizing agent, was used. Inkjet recording paper was prepared in the same manner as Example 10. The basis weight of the obtained paper was 60 g / m ² and a thickness of 93 μm (specific volume 1.55 cm ³ / g).

(Example 16)
In Example 11, as a size press solution, 2% oxidized starch (MS # 3800: manufactured by Nippon Shokuhin Kako Co., Ltd.), 3% polyamine resin (DK6810: manufactured by Seiko PMC) as a cationic polymer as an ink fixing agent Except that an aqueous solution of a cationic alkyl ketene dimer (SE2360: manufactured by Seiko PMC) 0.05% and a polyvinyl alcohol (PVA117: manufactured by Kuraray) 1% having a saponification degree of 99 mol%, which is a cationic sizing agent, was used. Inkjet recording paper was prepared in the same manner as in Example 11. The basis weight of the obtained paper was 60 g / m ² and a thickness of 93 μm (specific volume 1.55 cm ³ / g).

(Comparative Example 1)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the cationic polymer as an ink fixing agent was not added to the size press solution. The obtained paper had a basis weight of 60 g / m ² and a thickness of 90 μm (specific volume: 1.50 cm ³ / g).

(Comparative Example 2)
Inkjet recording paper was prepared in the same manner as in Example 1 except that the Canadian standard freeness of pulp was changed to 600 ml CSF. The basis weight of the obtained paper was 60 g / m ² , and the thickness was 126 μm (specific volume 2.10 cm ³ / g).

The obtained inkjet recording paper was subjected to the following evaluation, and the results are shown in Tables 1, 2, and 3. 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 elongation in water:
The elongation in water in the direction of the width of the paper is measured according to JAPAN TAPPI No. 27 Measured according to “Testing method for water and paper board elongation”. The measurement time was 5 minutes.

(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) Solid part unevenness:
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 unevenness of the printed solid part was visually determined and evaluated in the following four stages.
A: There is no unevenness and it can be used practically.
○: Although there is slight unevenness, it can be practically used.
Δ: Uneven and impractical.
X: Unevenness is marked and impractical.

(4) Wrinkle evaluation:
Using a commercial inkjet printer (HP T300 Color InkjetPress: manufactured by Hewlett-Packard Company), a black solid of 100 cm ² was printed on the obtained inkjet recording paper at a printing speed of 122 m / min. Whether or not wrinkles were generated in the printed solid portion was determined by visual observation, and evaluated in the following four stages.
(Double-circle): There is no wrinkle at all and it can be used practically.
○: There are slight wrinkles, but it is hardly visible to the naked eye and can be used practically.
Δ: Wrinkled and not practical.
X: Wrinkles are remarkable and impractical.

  As is clear from Tables 1, 2, and 3, the ink jet recording paper obtained in Examples 1 to 16 was 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. Furthermore, the occurrence of wrinkles during ink jet printing was suppressed, and the printability was excellent.

  On the other hand, since the ink jet recording paper obtained in Comparative Example 1 did not contain a cationic polymer, the ink oozed significantly and the solid portion was significantly uneven. The ink jet recording paper obtained in Comparative Example 2 was wrinkled during ink jet printing because the underwater elongation of the side of the paper exceeded 3.0%.

Claims (3)

  An ink jet recording paper that does not have a coating layer containing an inorganic pigment, contains an ink fixing agent and a bulking agent, the ink fixing agent is a cationic polymer, and has an elongation in water in the transverse direction of the paper. An inkjet recording paper, characterized by being 3.0% or less. 2. The inkjet recording paper according to claim 1, wherein the specific volume is 1.25 to 2.00 cm ³ / g.   A paper stock containing 350 to 485 ml CSF pulp and fatty acid polyamidoamine as a bulking agent was made in accordance with Canadian standard freeness (JIS P 8121: 1995 “Testing method for freeness of pulp”). 3. The method for producing an ink jet recording paper according to claim 1, wherein an aqueous solution containing a cationic polymer as an ink fixing agent is applied to the web after being obtained, and then dried.