JP6212458B2 - Inkjet printing paper - Google Patents

Description

  The present invention relates to an inkjet printing paper.

  The ink jet recording system is a system in which dots are formed by ejecting droplets of dye ink or pigment ink and depositing them on recording paper to perform recording. In recent years, recording with high print quality has become possible due to technological advances in inkjet printers, inks, and recording media. In fields such as commercial printing, a so-called on-demand printing method that digitizes variable information and prints at high speed is being introduced, and ink jet printers that adopt the on-demand printing method are also appearing. Such an 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. Recently, along with the expansion of applications due to remarkable progress in speeding up or high definition of equipment, there has been a demand for imparting inkjet suitability to general coated paper for printing (for example, general offset printing paper). Have been doing. In particular, recently, since the speed of the apparatus has been increased, a paper having better ink absorbability has been demanded.

  In general printing coated paper, a coating layer containing a pigment and a binder is provided. As the pigment, calcium carbonate is generally used, and in particular, light calcium carbonate is used from the viewpoint of improving the acceptability of the ink and improving the whiteness of the coating layer. Moreover, as a binder, in order to provide appropriate printing strength, it is common to use a styrene butadiene latex. However, when such a general printing coated paper is applied to an ink jet printer, the ink absorbability of the ink jet ink is remarkably worse than that of the general ink jet paper, and the image sharpness and ink absorbability can be practically used. is not. The reason for this is that the pore volume of light calcium carbonate used as a pigment in the coating layer is relatively low, and that the styrene butadiene latex used as the binder significantly reduces the pore volume of the coating layer. It is done. The ink receiving layer of the conventional ink jet paper uses a pigment having a pore volume larger than that of light calcium carbonate such as silica, alumina, or boehmite as a main component to enhance the ink absorbability of the coating layer. However, since these pigments are expensive, they are not practical for use in general printing coated paper in the commercial printing field.

  As described above, since there are various problems in applying a general printing coated paper to an ink jet printer, printing paper with various improvements has been developed. As such a printing paper, a printing paper is disclosed in which a coating layer contains a large amount of an inkjet ink fixing agent made of a cationic compound (see, for example, Patent Document 1). Further, a printing paper in which light calcium carbonate having a specific shape is contained in a coating layer is disclosed (for example, see Patent Document 2).

Japanese Patent No. 5455280 JP 2013-132854 A

  However, since the cationic compound disclosed in Patent Document 1 has a too high degree of cationization, when used in combination with the styrene butadiene latex, the coating solution for the coating layer excessively aggregates, resulting in Further, there is a problem that the coating layer strength is lowered and the printability such as normal offset printing is impaired. Further, in the case of Patent Document 2, it is difficult to desire a certain level of ink absorptivity, and the coating layer strength tends to decrease.

  The present invention has been made in view of such problems, and the object of the present invention is to provide a coating layer containing light calcium carbonate and styrene butadiene latex as in general printing coated paper. An object of the present invention is to provide an ink jet printing paper having good absorbability of the ink jet ink while having it. Another object of the present invention is to provide an inkjet printing paper having a coating layer strength suitable for general printing such as offset printing.

In order to solve the above problems, an ink jet printing paper according to the present invention is an ink jet printing paper in which an ink receiving layer containing a pigment and a binder is provided on at least one side of a base paper. Containing light calcium carbonate and silica, styrene butadiene latex as the binder , and cationic polymer, the cationic polymer having a cationization degree of 0 meq / g It is a slightly cationic polymer of more than 3.00 meq / g and the content of the slightly cationic polymer is 0.01 to 0.05 parts by mass with respect to 100 parts by mass of the pigment in the ink receiving layer. And the at least one cationic polymer is selected from a polyamine resin, a polyamide resin and a polyacrylamide resin. Characterized in that it is a one. It is possible to achieve both excellent ink absorbability and excellent coating layer strength.

  In the inkjet printing paper which concerns on this invention, it is preferable that 20-100 mass parts is light calcium carbonate among 100 mass parts of said pigments. By coexisting with a slightly cationic polymer, the ink absorbability can be further enhanced.

  ADVANTAGE OF THE INVENTION According to this invention, although it has the coating layer containing a calcium carbonate and a styrene butadiene latex like a general printing coated paper, it can be set as the inkjet printing paper with the favorable absorbability of an inkjet ink. it can. Moreover, it can be set as the inkjet printing paper which has a coating layer intensity | strength suitable for general printing, such as offset printing. And since the printing paper of this invention can maintain the manufacturing efficiency similar to the conventional general printing coated paper, it becomes possible to provide an inkjet printing paper cheaply.

  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.

In order to increase the pores of the ink receiving layer while maintaining the strength of the ink receiving layer, the present inventors have added a slightly cationic polymer in the ink receiving layer containing light calcium carbonate and styrene butadiene latex. By containing it, the ink absorptivity was successfully improved. Moreover, it discovered that it had general printing aptitudes, such as offset printing, by the said method similarly to the coating paper for general printing, and it came to this invention. That is, the ink jet printing paper according to this embodiment is an ink jet printing paper in which an ink receiving layer containing a pigment and a binder is provided on at least one side of a base paper. The ink receiving layer contains light calcium carbonate as a pigment. And no silica, styrene butadiene latex as the binder, and a cationic polymer , the cationic polymer having a degree of cationization of more than 0 meq / g and not more than 3.00 meq / g And the content of the fine cationic polymer is 0.01 to 0.05 parts by mass with respect to 100 parts by mass of the pigment in the ink receiving layer, The molecule is at least one selected from a polyamine resin, a polyamide resin, and a polyacrylamide resin .

(1) Base paper As pulp used for the base paper of the inkjet printing paper according to the present embodiment, chemical pulp such as LBKP (hardwood bleached kraft pulp) or 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) or CGP (chemiground pulp) It is possible to use wood pulp such as ink pulp) or non-wood pulp such as kenaf, bagasse, bamboo or cotton. These can be used alone or in admixture at any ratio. In addition, a synthetic fiber can be further blended within a range that does not impair the intended effect of the present invention. From the viewpoint of environmental conservation, it is more preferable to use ECF (Elemental Chlorine Free) pulp, TCF (Total Chlorine Free) pulp, waste paper pulp or pulp obtained from planted trees.

  As the filler used for the base paper, for example, light calcium carbonate, heavy calcium carbonate, talc, clay, kaolin, calcined clay, titanium dioxide, and aluminum hydroxide can be used. The filler content in the base paper is preferably 2 to 30 parts by mass with respect to 100 parts by mass of the dry mass of the pulp. More preferably, it is 3-17 mass parts. More preferably, it is 4-15 mass parts. If it is 2 parts by mass or less, effects such as whiteness improvement and opacity improvement cannot be obtained. When the amount exceeds 30 parts by mass, the strength of the paper itself is insufficient, and it cannot withstand printing and processing and cannot be used.

  For the base paper, in addition to pulp and filler, internal paper strength enhancers such as internal sizing agents and wet paper strength enhancers, bulking agents, yield improvers, drainage improvers, colored dyes, color pigments, fluorescent enhancers Various auxiliary agents such as a whitening agent, a fluorescence decoloring agent, or a pitch control agent can be appropriately blended. Various known sizing agents can be used, and are not particularly limited. For example, reinforced rosin sizing agent, acidic rosin sizing agent, weakly acidic rosin sizing agent, AKD (alkyl ketene dimer) or ASA (alkenyl succinic anhydride) ). As the internal paper strength enhancer, a conventionally known paper strength enhancer can be used, for example, starch based paper strength enhancer, polyacrylamide based paper strength enhancer or polyvinyl alcohol based paper strength enhancer. is there.

  The method of making the base paper is not particularly limited, and is a long net paper machine, a long net multi-layer paper machine, a circular net paper machine, a circular net multi-layer paper machine, a long net circular net combination multi-layer paper machine, or a twin wire paper machine. It can be manufactured by various devices such as a machine.

Further, a surface size liquid may be applied to the base paper. Examples of the surface sizing solution include, but are not particularly limited to, an aqueous solution containing a known water-soluble polymer such as starch, polyvinyl alcohol, or polyacrylamide. Although the basic weight of a base paper is not specifically limited, Usually, it is 30-400 g / m < ² >. More preferably, it is 50-350 g / m < ² >.

  There is no problem even if an under layer provided by applying a coating liquid mainly composed of a pigment and a binder is applied to one side or both sides of the base paper obtained by the above method. The coated paper after having been used can be used as the base paper of the inkjet printing paper according to the present embodiment.

(2) Ink Receiving Layer In the ink jet printing paper according to the present embodiment, an ink receiving layer containing a pigment, a styrene butadiene latex, and a slightly cationic polymer is provided on at least one side of the base paper. In the present invention, the ink receiving layer refers to the outermost coating layer of the inkjet printing paper. The ink receiving layer contains light calcium carbonate as a pigment. By coexisting light calcium carbonate and a slightly cationic polymer in the ink receiving layer, it is considered that the pore volume of the ink receiving layer is further increased and the ink absorbability is improved. The cause is considered to be that the pore volume of the ink receiving layer increases moderately because the agglomeration effect of light calcium carbonate and the slightly cationic polymer is moderately large. By using a combination of light calcium carbonate and a slightly cationic polymer, the pore volume of the ink receiving layer can be adjusted to 0.1 to 0.5 cm ³ / g, for example. The pore volume of the ink receiving layer is more preferably 0.2 to 0.4 cm ³ / g. In the present specification, the pore volume means a pore volume measured by a nitrogen adsorption method.

  The content of the light calcium carbonate is preferably 20 to 100 parts by mass with respect to 100 parts by mass of the pigment contained in the ink receiving layer. More preferably, it is 25-85 mass parts. Here, the light calcium carbonate content is the content per one side when the ink receiving layer is provided on both sides of the base paper. By increasing the ratio of light calcium carbonate to the total pigment in the ink receiving layer, the pore volume of the ink receiving layer is further increased and the ink absorbency is improved due to the proper coagulation with the slightly cationic polymer. To do. If the amount of light calcium carbonate added is less than 20 parts by mass, ink absorbability may be insufficient.

The light calcium carbonate preferably has a 50 volume% particle diameter (D ₅₀ ) of a particle size distribution curve by a laser diffraction method of 0.8 to 10 μm, and more preferably 1.3 to 5.0 μm. The D ₅₀ in this range, it is possible to further improve the ink absorbency.

  The pigment that can be used in combination with light calcium carbonate is not particularly limited, and a known pigment used for a coating layer of a general printing coated paper can be used, for example, heavy calcium carbonate, These are fine particles of organic polymers such as kaolin (including clay), calcined clay, inorganic pigments such as zinc oxide, titanium oxide or aluminum hydroxide, or plastic pigments. Among these, one or more kinds are appropriately selected and used according to the purpose. In this embodiment, it is more preferable to use a combination of light calcium carbonate and kaolin. By using light calcium carbonate and kaolin together, ink absorbency and gloss can be improved.

  In the present embodiment, the ink receiving layer contains styrene butadiene latex as a binder. By using styrene butadiene latex as a binder for the ink receiving layer, the strength of the coating layer can be made as high as that of conventional coated paper for general printing. Moreover, since it is inexpensive, it is possible to keep the manufacturing cost low. Furthermore, the fall of a blank paper surface can be prevented by preventing the coating layer from falling off and suppressing the dirt on the calendar roll during the calendar process.

  In the present embodiment, other binders can be further used in addition to the styrene butadiene latex as the binder of the ink receiving layer. Examples of other binders that can be used in combination with styrene-butadiene latex include starches such as oxidized starch, enzyme-modified starch, esterified starch, etherified starch, cationic starch, and amphoteric starch, gelatin, casein, soy protein, and polyvinyl alcohol. Or a synthetic resin such as vinyl acetate, ethylene vinyl acetate, polyurethane resin, acrylic resin, polyester resin, or polyamide resin. Among these, one or more kinds are appropriately selected and used according to the purpose. In particular, a combination of starch and styrene butadiene latex is preferable from the viewpoint of coating layer strength of the ink receiving layer and cost reduction. However, even in the case of using the above-mentioned other binders, in order to satisfy the coating layer strength and maintain the same production efficiency as a general printing coated paper, to make an inexpensive inkjet printing paper. Further, the ratio of the styrene butadiene latex in the total amount of the binder in the ink receiving layer is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. Here, the ratio of the styrene butadiene latex is a ratio per one side when the ink receiving layer is provided on both sides of the base paper. In addition, when using together starch mentioned above and styrene butadiene latex, it is preferable to use together by the ratio of starch: styrene butadiene latex = 10: 90-40: 60 by mass ratio, More preferably, it is 15:85. 30:70. That is, it is preferable that the mass of starch is 10-40 mass parts, and it is more preferable that it is 15-30 mass parts with respect to 100 mass parts of total mass of starch and styrene butadiene latex.

  Although the compounding quantity of the binder in an ink receiving layer is not specifically limited, It is preferable to set it as 3-50 mass parts with respect to 100 mass parts of pigments in an ink receiving layer, and it is more preferable to set it as 5-40 mass parts. If the blending amount is less than 3 parts by mass, the coating layer may fall off and the coating layer strength may be impaired. If it exceeds 50 parts by mass, the ink absorbability may not be satisfied.

  In this embodiment, the ink receiving layer contains a slightly cationic polymer. In the present invention, the slightly cationic polymer refers to a polymer having a degree of cationization of more than 0 meq / g and not more than 3.00 meq / g. The degree of cationization of the cationic ink fixing agent used for ink jet printing paper usually exceeds 3.00 meq / g. The cationic ink fixing agent is, for example, a cationic compound disclosed in Patent Document 1. While the cationic ink fixing agent used in general inkjet printing papers directly affects the improvement of ink fixability, the slightly cationic polymer has an ink aggregating action with light calcium carbonate. Increasing the pore volume of the layer serves to improve the ink absorbency of the ink receiving layer. Further, the slightly cationic polymer is appropriately aggregated with the styrene butadiene latex. That is, by including a slightly cationic polymer in the ink receiving layer, the pore volume of the coating layer is appropriately increased in the drying step of the ink receiving layer, and the ink absorbability is improved. By using a slightly cationic polymer, the coating solution for the ink-receiving layer is not excessively aggregated even when light calcium carbonate is used as the pigment and styrene butadiene latex is used as the binder. In addition, an ink receiving layer having excellent coating layer strength can be obtained.

  As a method for incorporating a slightly cationic polymer in the ink receiving layer, a coating liquid containing light calcium carbonate, styrene butadiene latex and a slightly cationic polymer (hereinafter referred to as an ink receiving layer coating liquid). Before applying the coating surface, after coating the base paper with a coating solution containing light calcium carbonate as a pigment and styrene butadiene latex as a binder and not containing a slightly cationic polymer. The method of apply | coating the coating liquid containing a slightly cationic polymer to the surface etc. is mentioned. Among these, a method of applying a coating solution for an ink receiving layer containing light calcium carbonate, styrene butadiene latex and a slightly cationic polymer to a base paper is more preferable. The fine cationic polymer, light calcium carbonate, and styrene butadiene latex can be appropriately aggregated over the entire depth direction of the coating layer. As a result, the ink absorbability can be further improved.

  The degree of cationization of the slightly cationic polymer is more preferably 0.05 to 3.00 meq / g from the viewpoint of maintaining high ink absorbability and coating layer strength. If it is less than 0.05 meq / g, the ink absorbability may be inferior. When it exceeds 3.00 meq / g, the cationic polymer excessively aggregates with light calcium carbonate and styrene butadiene latex, a smooth coating surface cannot be obtained, and the coating layer strength of the ink receiving layer is inferior. The degree of cationization of the slightly cationic polymer is particularly preferably 0.10 to 2.50 meq / g. The degree of cationization can be measured by a colloid titration method.

  The content of the slightly cationic polymer in the ink receiving layer is preferably 0.01 to 3.00 parts by mass with respect to 100 parts by mass of the pigment in the ink receiving layer. Here, the content of the slightly cationic polymer in the ink receiving layer is the content per one side when the ink receiving layer is provided on both sides of the base paper. If it is less than 0.01 parts by mass, the ink absorbability may be lowered. If it exceeds 3.00 parts by mass, the coating layer strength of the ink receiving layer may be inferior. The content of the slightly cationic polymer is more preferably 0.05 to 2.00 parts by mass with respect to 100 parts by mass of the pigment in the ink receiving layer.

  Examples of the slightly cationic polymer that can be used in this embodiment include polyethyleneimine, epichlorohydrin-modified polyalkylamine, polyamine, polyamine polyamide epichlorohydrin, dimethylamine ammonia epichlorohydrin, polyvinylbenzyltrimethylammonium halide, polydiacryldimethylammonium halide, polydimethyl. Aminoethyl methacrylate hydrochloride, polyvinylpyridium halide, cationic polyacrylamide, cationic polystyrene copolymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride sulfur dioxide copolymer, diallyldimethylammonium chloride amide copolymer, dicyandiamide Formalin polycondensate, dicyandiamide diethylene Triamine 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, Among the polyamidine compounds, modified polyamine resins, modified polyamide resins, other quaternary ammonium salts, and cationic modified polyurethane resins, those are slightly cationic. When contained in the ink receiving layer coating liquid described above, it is preferably in the form of an aqueous solution or an emulsion. A slightly cationic polymer may be used individually by 1 type, or may use 2 or more types together. In this embodiment, it is more preferable that the slightly cationic polymer is at least one selected from a polyamine resin, a polyamide resin, and a polyacrylamide resin.

  Moreover, you may mix | blend various adjuvants suitably with an ink receiving layer as needed. The various auxiliary agents include, for example, viscosity modifiers, softeners, gloss imparting agents, dispersants, flow modifiers, UV absorbers, stabilizers, antistatic agents, fluorescent brighteners, colorants, pH adjusters, extinction agents. A foam, plasticizer or preservative.

(3) Coating system The ink jet printing paper according to the present embodiment can be obtained, for example, by coating the surface of the base paper with an ink receiving layer coating liquid and drying it. In addition, the inkjet printing paper according to the present embodiment forms a coated surface by applying a coating liquid containing light calcium carbonate and styrene butadiene latex and not containing a slightly cationic polymer to the surface of the base paper. In addition, while the coated surface is in a wet state, a coating solution containing a slightly cationic polymer may be coated on the coated surface and dried. The coating method of the ink receiving layer coating liquid or various coating liquids is not particularly limited, and a commonly used known coating apparatus is used. Coating equipment includes, for example, air knife coaters, blade coaters, gravure coaters, rod blade coaters, roll coaters, reverse roll coaters, bar coaters, curtain coaters, die slot coaters, Champlex coaters, metering blade type size press coaters Short dwell coater, spray coater, gate roll coater or lip coater.

The coating amount of the ink receiving layer is not particularly limited, but is preferably ² to 40 g / m ^{2 in} terms of solid content per one side of the base paper. More preferably, it is 5-30 g / m < ² >, More preferably, it is 8-20 g / m < ² >. If the coating amount is less than 2 g / m ² , it may be difficult to obtain a desired white paper gloss. If it exceeds 40 g / m ² , it may be disadvantageous in terms of cost.

(4) Calendar process The inkjet printing paper according to the present embodiment may be given a gloss by performing a calendar process in the same manner as a general coated paper for printing. It is preferable to perform a calendering treatment after coating the ink-receiving layer coating material on the base paper and drying it. As the calendar processing apparatus, a normal super calendar, gloss calendar, shoe nip calendar, soft calendar or the like is used. Processing conditions such as the pressure device configuration, the number of pressing nips, or temperature conditions during the calendar processing can be adjusted as appropriate.

  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
(Preparation of base paper)
Canadian Standard Freeness 480mlcsf hardwood bleached kraft pulp 100 parts, light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.) 8 parts, cationized starch (trade name: Neotac 30T, manufactured by Nippon Food Processing Co., Ltd.) Part, neutral rosin size (trade name: CC167, manufactured by Seiko PMC Co., Ltd.) 0.18 part, water is added to prepare a stock, and basis weight is 67.5 g / m ² using a long mesh multi-cylinder paper machine. A base paper was prepared. The base paper is coated with oxidized starch (trade name: MS3800, manufactured by Nippon Shokuhin Kako Co., Ltd.) on this base paper so that the dry coating amount per side is 2.5 g / m ² and dried to obtain a base paper. It was.

(Preparation of ink receiving layer coating solution)
50 parts of kaolin (trade name: Contour 1500, manufactured by Imeris) and 50 parts of light calcium carbonate (trade name: TP-121MS, average particle diameter of 1.7 μm, manufactured by Okutama Kogyo Co., Ltd.) (-50, manufactured by Toa Gosei Co., Ltd.) 0.25 part was added, and the mixture was added with water and dispersed in water using a Coreless disperser to prepare a pigment slurry. To this pigment slurry, 2 parts of phosphate esterified starch (trade name: MS4600, manufactured by Nippon Food Processing Co., Ltd.) and 9 parts of styrene butadiene latex (trade name: PA0372, manufactured by Nippon A & L Co., Ltd.) as a binder, a slightly cationic polymer As a modified polyamine-based resin (trade name: PA629, cationization degree 0.05 meq / g, manufactured by Seiko PMC Co., Ltd.) 0.05 parts, water is further added and dispersed to form an ink receiving layer having a solid content concentration of 55%. A coating solution was prepared.

(Preparation of inkjet printing paper)
The ink receiving layer coating solution was applied to both sides of the base paper obtained above using a blade coater so that the dry coating amount per side was 10 g / m ² and dried. Then, the calendar process was performed and the inkjet printing paper whose basic weight is 90 g / m < ² > was produced.

(Example 2)
In Example 1, a slightly cationic polymer was changed from 0.05 part of a modified polyamine resin (trade name: PA629, cationization degree 0.05 meq / g, manufactured by Seiko PMC) to a polyacrylamide resin (trade name: Flock). Inkjet printing paper was prepared in the same manner as in Example 1 except that it was changed to 0.05 parts (star ESC51, cationization degree 1.2 meq / g, manufactured by Sanki Co., Ltd.).

(Example 3)
In Example 1, the slightly cationic polymer was changed from 0.05 part of a modified polyamine resin (trade name: PA629, cationization degree 0.05 meq / g, manufactured by Seiko PMC) to a modified polyamine resin (trade name: (Sumirez Resin SPI-102A, cationization degree 1.9 meq / g, manufactured by Taoka Chemical Co., Ltd.) An ink jet printing paper was prepared in the same manner as in Example 1 except that the amount was changed to 0.05 part.

Example 4
In Example 1, a slightly cationic polymer was changed from 0.05 part of a modified polyamine resin (trade name: PA629, cationization degree 0.05 meq / g, manufactured by Seiko PMC) to a modified polyamide resin (trade name: (Sumirez Resin SPI-203 (50) H, cationization degree 3.0 meq / g, manufactured by Taoka Chemical Co., Ltd.) An ink jet printing paper was prepared in the same manner as in Example 1 except that it was changed to 0.05 part.

(Example 5)
Inkjet printing paper was prepared in the same manner as in Example 1 except that the amount of the slightly cationic polymer added was 0.01 parts in Example 1.

( Reference Example 6)
Inkjet printing paper was prepared in the same manner as in Example 1 except that the amount of the slightly cationic polymer added was 1.0 part in Example 1.

( Reference Example 7)
Inkjet printing paper was prepared in the same manner as in Example 1 except that the amount of the slightly cationic polymer added was 3.0 parts in Example 1.

(Example 8)
In the preparation of the ink receiving layer coating liquid of Example 1, the amount of kaolin (trade name: Contour 1500, manufactured by Imeris) was 90 parts, and light calcium carbonate (trade name: TP-121MS, Okutama Kogyo Co., Ltd.). An ink jet printing paper was prepared in the same manner as in Example 1 except that the amount of addition was 10 parts.

Example 9
In the preparation of the ink receiving layer coating solution of Example 1, the amount of kaolin (trade name: Contour 1500, manufactured by Imeris) was 80 parts, and light calcium carbonate (trade name: TP-121MS, Okutama Kogyo Co., Ltd.). An ink jet printing paper was prepared in the same manner as in Example 1 except that the amount of addition was 20 parts.

(Example 10)
In the preparation of the ink receiving layer coating liquid of Example 1, the amount of kaolin (trade name: Contour 1500, manufactured by Imeris) was 20 parts, and light calcium carbonate (trade name: TP-121MS, Okutama Kogyo Co., Ltd.). An ink jet printing paper was prepared in the same manner as in Example 1 except that the amount of addition was 80 parts.

(Example 11)
In the preparation of the ink receiving layer coating liquid of Example 1, kaolin (trade name: Contour 1500, manufactured by Imeris) was not added, and light calcium carbonate (trade name: TP-121MS, manufactured by Okutama Kogyo Co., Ltd.) was used. An ink jet printing paper was prepared in the same manner as in Example 1 except that the addition amount was 100 parts.

Example 12
In the preparation of the ink receiving layer coating solution of Example 1, 50 parts of light calcium carbonate (trade name: TP-121MS, manufactured by Okutama Kogyo Co., Ltd.) were mixed with light calcium carbonate (trade name: TP-121, average particle size 2). 0.6 μm, manufactured by Okutama Kogyo Co., Ltd.) Inkjet printing paper was prepared in the same manner as in Example 1 except that the amount was changed to 50 parts.

(Comparative Example 1)
Inkjet printing paper was prepared in the same manner as in Example 1 except that the slightly cationic polymer was not added.

(Comparative Example 2)
In Example 1, instead of a slightly cationic polymer, a cationic polyamidine resin (trade name: Himax SC-700L, cationization degree 4.5 meq / g, manufactured by Hymo Co., Ltd.), which is a fixing agent for inkjet ink, 0 An inkjet printing paper was prepared in the same manner as in Example 1 except that .05 parts was added.

(Comparative Example 3)
In the preparation of the ink-receiving layer coating liquid of Example 1, 50 parts of light calcium carbonate (trade name: TP-121MS, manufactured by Okutama Kogyo Co., Ltd.) was replaced with 50 parts of heavy calcium carbonate (Carbillax, manufactured by Imeris Co., Ltd.). An ink jet printing paper was prepared in the same manner as in Example 1 except for the change.

  The obtained inkjet printing paper was evaluated by the following method. The obtained results are shown in Tables 1 and 2.

(1) Ink absorbability evaluation Using the following two types of ink jet printers on the obtained ink jet printing paper, printing is performed by creating a pattern in which mixed color solid parts having different hues are arranged next to each other, and the border blur of each solid part is produced. The condition was evaluated visually as follows. If the ink absorptivity is poor, the boundary tends to blur.
Printer A: CM8060 Color MFP (manufactured by Hewlett-Packard) (for on-demand printing)
Printer B: PX-101 (manufactured by EPSON) (for personal use)
(Double-circle): There is no bleeding and it can be used practically. Pass.
○: Slight bleeding occurs but can be used practically. Pass.
(Triangle | delta): A bleeding generate | occur | produces and it cannot use. failure.
X: Significant bleeding occurs, impractical. failure.

(2) Strength of ink receiving layer Offset printing was performed on the obtained ink jet printing paper, and blanket contamination after printing was evaluated. The lower the coating layer strength, the easier the blanket gets dirty.
(Double-circle): There is no blanket dirt and it can be used practically. Pass.
○: Slight blanket stains are generated, but can be used practically. Pass.
Δ: Blanket stains occur and impractical. failure.
X: Blanket stains occur remarkably and are not practical. failure.

As is clear from Tables 1 and 2, the inkjet printing papers obtained in Examples 1 to 5 and 8 to 11 have good absorbability of inkjet ink and excellent coating layer strength of the ink receiving layer. there were. Therefore, it is expected that the ink-jet printing paper has good printability with an ink-jet printer and is suitable for general printing such as offset printing.

  On the other hand, the ink jet printing paper obtained in Comparative Example 1 was inferior in ink absorptivity because the fine cationic polymer was not contained in the ink receiving layer. The inkjet printing paper obtained in Comparative Example 2 was inferior in the coating layer strength because it was not a slightly cationic polymer but contained a high cationization degree fixing agent for inkjet ink in the ink receiving layer. The ink jet printing paper obtained in Comparative Example 3 was inferior in ink absorbability because light calcium carbonate was not contained in the ink receiving layer.

  The ink jet printing paper according to the present embodiment has good printability with an ink jet printer and is suitable for general printing such as offset printing. The ink jet printing paper according to the present embodiment can be used as an on-demand ink jet printing paper.

Claims (2)

In an inkjet printing paper provided with an ink receiving layer containing a pigment and a binder on at least one side of the base paper,
The ink-receiving layer contains light calcium carbonate as the pigment, does not contain silica, contains a styrene butadiene latex as the binder, and contains a cationic polymer, A slightly cationic polymer having a degree of cationization of more than 0 meq / g and not more than 3.00 meq / g,
The content of the slightly cationic polymer is 0.01 to 0.05 parts by weight with respect to 100 parts by weight of the pigment in the ink receiving layer, and the slightly cationic polymer is a polyamine resin or a polyamide resin. And at least one selected from polyacrylamide-based resins .   The inkjet printing paper according to claim 1, wherein 20 to 100 parts by mass of light pigments of 100 parts by mass of the pigment is light calcium carbonate.