WO2010113721A1 - Coated paper for printing - Google Patents

Coated paper for printing Download PDF

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Publication number
WO2010113721A1
WO2010113721A1 PCT/JP2010/055077 JP2010055077W WO2010113721A1 WO 2010113721 A1 WO2010113721 A1 WO 2010113721A1 JP 2010055077 W JP2010055077 W JP 2010055077W WO 2010113721 A1 WO2010113721 A1 WO 2010113721A1
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WO
WIPO (PCT)
Prior art keywords
printing
paper
coated paper
weight
monocarbonate
Prior art date
Application number
PCT/JP2010/055077
Other languages
French (fr)
Japanese (ja)
Inventor
裕介 近藤
久和 松木
正典 川島
清 畠山
治 小塚
Original Assignee
日本製紙株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2009086180A external-priority patent/JP4668327B2/en
Priority claimed from JP2009086719A external-priority patent/JP4668328B2/en
Application filed by 日本製紙株式会社 filed Critical 日本製紙株式会社
Publication of WO2010113721A1 publication Critical patent/WO2010113721A1/en

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/36—Coatings with pigments
    • D21H19/38—Coatings with pigments characterised by the pigments

Definitions

  • the present invention relates to a coated paper for printing excellent in rigidity and printing characteristics.
  • whiteness, opacity, white paper gloss, and print gloss are important qualities for printing coated paper. Furthermore, a thin coated paper with a low coating amount is required to have a quality such as a white paper surface or a print surface, and it is also important that it is difficult to see through.
  • Through-through is a phenomenon in which the printed surface can be seen through the printed surface (through-through surface). It is easy and the improvement is an important issue.
  • securing the surface strength of the printing paper is also a major technical issue. That is, if the coating amount is reduced due to weight reduction, the surface strength required at the time of printing cannot be ensured, and there may be a trouble that the surface of the coated paper or the pile is blurred at the time of printing.
  • a relatively strong tack ink is used, so that it is easy to generate piling, and it is necessary to maintain the surface strength of the coated paper for printing even if it is a low basis weight product.
  • the basis weight of the base paper there are a method of reducing the basis weight of the base paper and a method of reducing the coating amount of the coating layer. If the base paper has a low basis weight, the paper thickness will be thin, and it will be easy to see through, and the rigidity will be lowered, so that it will be easy to cause a problem with corner folding in offset rotary printing. On the other hand, if the coating layer has a low coating amount, the base paper coverage of the coating layer is deteriorated, so that the whiteness and the printing surface are deteriorated, and the surface strength is lowered.
  • an object of the present invention is to provide a coated paper for printing having excellent rigidity (rigidity) and printing quality in a coated paper for printing, particularly a thin coated paper for printing. It is.
  • an object of the present invention is to provide a coated paper for printing having high whiteness, high opacity, excellent print quality such as back-through, and high rigidity and surface strength.
  • the present inventors have determined that calcium aluminate monocarbonate having an average particle diameter of 2 to 15 ⁇ m is used as the pigment of the pigment coating layer. When blended, it was found that a coated paper for printing with high rigidity and excellent print quality was obtained, and the present invention was completed.
  • the coated paper for printing of the present invention has high rigidity and surface strength while having a low basis weight, and is excellent in printing quality such as whiteness, opacity, and back-through.
  • the present invention relates to a coated paper for printing having a base paper and a pigment coating layer, and uses calcium aluminate monocarbonate having an average particle diameter of 2 to 15 ⁇ m as a pigment constituting the pigment coating layer.
  • Coated paper for printing The coated paper for printing of the present invention can be suitably used for various printing applications. For example, it is used in printing systems such as planographic printing such as offset printing, intaglio printing such as gravure printing, and relief printing. can do.
  • the printing coated paper of the present invention can be used for various coated papers depending on the purpose, but is suitable as a low basis weight printing coated paper such as A3 coated paper because it is excellent in rigidity and back-through. It is particularly suitable as a coated paper for printing used in commercial printed materials such as leaflets and catalogs.
  • the basis weight of the coated paper for printing of the present invention is not particularly limited, but according to the present invention, high rigidity and surface strength can be obtained even at a low basis weight, and therefore 30 to 60 g / m 2 is preferable, and 30 to 50 g / m 2 is preferable. 2 is more preferable, and 40 to 50 g / m 2 is more preferable.
  • the ISO bending stiffness of the coated paper for printing of the present invention is not particularly limited, and can be determined as appropriate according to usage conditions such as a printing press and a printing speed.
  • the machine direction ( Machine Direction: bending in MD) stiffness is preferably 30 ⁇ 80 ⁇ N ⁇ m 2 / m , more preferably 50 ⁇ 80 ⁇ N ⁇ m 2 / m , more preferably 60 ⁇ 70 ⁇ N ⁇ m 2 / m .
  • the coated paper for printing of the present invention is suitable as a gravure printing paper because the superiority of the present invention, such as excellent gravure printing properties and rigidity, is obtained particularly when the basis weight is low, and the basis weight is 35 to 200 g. / M 2 is preferable, 35 to 100 g / m 2 is more preferable, 35 to 70 g / m 2 is more preferable, and not only gravure suitability but also printing workability at a low basis weight of 35 to 50 g / m 2.
  • the effect of the present invention that it is favorable can be enjoyed.
  • the coated paper for printing of the present invention has high rigidity, the paper passing property and the printing surface quality in gravure printing are improved.
  • Stiffness gravure coated printing paper of the present invention is different depending the basis weight and coating weight, as excellent low basis weight in a even printing workability, Clark stiffness in the MD direction is 20 cm 3 / 100 or more is preferable.
  • Calcium aluminate monocarbonate The coated paper for printing of the present invention contains calcium aluminate monocarbonate having an average particle diameter of 2 to 15 ⁇ m in the pigment coating layer.
  • Calcium aluminate monocarbonate (hereinafter also referred to as monocarbonate) is a crystalline substance having a composition of 3CaO ⁇ Al 2 O 3 and is obtained in a state of being hydrated with water molecules.
  • Monocarbonate has a layered structure, is composed of hexagonal plate-like primary particles similar to kaolin, and is generally synthesized from slaked lime and aluminum hydroxide.
  • the average particle size (volume basis) of the calcium aluminate monocarbonate of the present invention is 2 to 15 ⁇ m.
  • the calcium aluminate monocarbonate has excellent rigidity and surface strength, and is also suitable for printing. Excellent coated paper for printing can be obtained.
  • the average particle size of monocarbonate is less than 2 ⁇ m, the glossiness of the pigment coating layer is improved, but the rigidity and surface strength are lowered.
  • the average particle diameter of monocarbonate exceeds 15 ⁇ m, the smoothness of the pigment coating layer is lowered, and it becomes difficult to obtain a good printing surface.
  • the average particle size (volume basis) of the calcium aluminate monocarbonate of the present invention is preferably 2 to 10 ⁇ m, more preferably 5 to 10 ⁇ m.
  • the particle diameter defined in the present invention is a volume-based average particle diameter measured by a laser diffraction method, and is measured using, for example, a laser diffraction particle size distribution measuring instrument such as MALVERN® Instruments Mastersizer. be able to.
  • the particle diameter of the pigment can also be measured by a sedimentation method, and for example, Sedigraph manufactured by Micromeritics can be used.
  • the blending amount of the calcium aluminate monocarbonate of the present invention may be appropriately determined according to the use and the like, and is not particularly limited, but may be 5 parts by weight or more out of 100 parts by weight of the pigment constituting the pigment coating layer.
  • the pigment coating layer can be formed using only calcium aluminum monocarbonate as a pigment.
  • the amount of calcium aluminate monocarbonate is 10 to 50 parts by weight, more preferably 10 to 40 parts by weight. With such an amount, the coated paper for printing of the present invention having excellent rigidity and surface strength can be obtained without adversely affecting workability during pigment coating.
  • the present invention when calcium aluminate monocarbonate having an average particle size of 2 to 15 ⁇ m is blended in the pigment coating layer, a coated paper for printing having excellent rigidity and surface strength and excellent printing quality can be obtained. Details are not clear, and the present invention is not limited to this, but the calcium aluminate monocarbonate of the present invention has a lower specific gravity than pigments such as kaolin and calcium carbonate, so it contains calcium aluminate monocarbonate. Then, since a bulky pigment coating layer is formed, it is estimated that the rigidity is improved.
  • the calcium aluminate monocarbonate of the present invention has a relatively regular plate shape, and the surface strength of the coating layer is improved by blending such a pigment into the pigment coating layer. When the average particle size is 2 ⁇ m or more, it is presumed that the pigment is less likely to drop off from the pigment coating layer, and that piling and smearing during printing are reduced.
  • the calcium aluminum monocarbonate of the present invention may be a commercially available product or a synthesized product. It is known that monocarbonate is formed in a hardened cement material in the same manner as satin white (3CaO.Al 2 O 3 .3CaSO 4 ). The particle size is a hexagonal plate with monocarbonate having a layered structure, whereas satin white has a needle shape, and when used as a pigment for coated paper, it tends to be oriented flat on the paper surface.
  • Calcium aluminum monocarbonate can be synthesized by a known method, for example, a method in which anhydrous calcium aluminate is reacted with calcium carbonate in water (Damon et al., “3CaO ⁇ Al 2 O 3 —CaSO 4 ⁇ 2H 2 O -CaCO 3 —Na 2 SO 4 —H 2 O Hydrate ”,“ Inorganic Materials ”, page 196, vol.4, 1997), mechanochemically slaked lime and carbonate by grinding aluminum hydroxide Examples include a method of reacting calcium and water in the presence of water (see JP 2008-37664 A).
  • the base paper used in the present invention is not particularly limited, and general paper such as high-quality paper, medium-quality paper, and recycled paper can be used, and it may be acid paper or neutral paper.
  • the basis weight of the base paper of the present invention is not particularly limited, but the coated paper of the present invention blended with carbonate is difficult to see through and has high surface strength, and is preferably 25 to 55 g / m 2 , preferably 30 to 50 g / m 2. Is more preferable, and 35 to 45 g / m 2 is more preferable.
  • the pulp used for the base paper of the present invention is not particularly limited, but, for example, raw materials for printing paper such as mechanical pulp (MP), regenerated pulp, hardwood kraft pulp (LKP), conifer kraft pulp (NKP), etc. In general, those commonly used can be suitably used, and one or two or more of these can be used as appropriate.
  • mechanical pulp include groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemiground pulp (CGP), semi-chemical pulp (SCP), and the like.
  • non-wood pulp such as linter pulp, hemp, bagasse, kenaf, esparto grass, and straw
  • semi-synthetic fibers such as rayon and acetate
  • synthetic fibers such as polyolefin, polyamide, and polyester Etc.
  • the filler used in the base paper of the present invention is not particularly limited.
  • calcium carbonate such as heavy calcium carbonate and light calcium carbonate, titanium oxide, clay, silica, talc, kaolin, calcined kaolin, deramikaolin.
  • Magnesium carbonate, barium carbonate, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, titanium oxide, bentonite and other inorganic fillers; urea-formalin resin, polystyrene resin , Organic fillers such as melamine resin, phenol resin, and fine hollow particles can be used alone or in appropriate combination of two or more.
  • recycled fillers made from papermaking sludge, deinking floss, etc. can also be used.
  • calcium carbonate as a filler because it is inexpensive and excellent in optical properties.
  • a composite filler such as a calcium carbonate-silica composite (for example, a light calcium carbonate-silica composite described in Japanese Patent Application Laid-Open No. 2003-212539 or Japanese Patent Application Laid-Open No. 2005-219945) can also be used.
  • a filler obtained by removing acid-soluble ones from the filler used in the neutral papermaking is used, and used alone or in appropriate combination of two or more.
  • the blending amount of the filler is preferably 2 to 25% by weight based on the total weight of the base paper. In the case of gravure printing paper, the content is more preferably 3 to 15% by weight.
  • papermaking chemicals generally used for the production of base paper can be used as appropriate.
  • sizing agents such as rosin-based sizing agents, synthetic sizing agents, petroleum resin-based sizing agents, and neutral sizing agents can be used as the internal sizing agent in the present invention.
  • An internal additive for papermaking such as a slime control agent can be appropriately added depending on the purpose.
  • a pigment coating layer described later can be provided.
  • the preliminary coating can be performed using an apparatus such as a size press, a gate roll coater, or a pre-metering size press.
  • the pigment coating layer of the present invention comprises a pigment and a binder, and can be provided on the base paper by a known method.
  • the pigment coating layer of the present invention is provided on one side or both sides of the base paper, and may be a single layer or two or more layers.
  • the coating amount of the pigment coating layer is not particularly limited, but since the carbonate of the present invention can exert its effect even at a low coating amount, it should be 2 to 10 g / m 2 per side. It is preferably 2 to 8 g / m 2 , more preferably 3 to 6 g / m 2 . In the case of gravure printing paper, it is preferably 2 to 35 g / m 2 per side, more preferably 3 to 20 g / m 2 , and further preferably 3 to 10 g / m 2 .
  • the coated paper for printing of the present invention may contain other pigments as long as carbonate having an average particle diameter of 2 to 15 ⁇ m is contained in the pigment coating layer.
  • the pigment used in the coating layer of the present invention include, but are not limited to, kaolin, clay, delaminated clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, calcium sulfate, and oxidation.
  • Inorganic pigments such as zinc, silicic acid, silicate, colloidal silica, and satin white can be used in combination with monocarbonate.
  • various binders are used in the pigment coating layer in addition to the pigment, but various binders can also be used in the present invention.
  • the adhesive used in the coating layer of the present invention include, for example, various copolymers such as styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, vinyl acetate / butyl acrylate, Or synthetic adhesives such as polyvinyl alcohol, maleic anhydride copolymer, acrylic acid / methyl methacrylate copolymer, proteins such as casein, soy protein, synthetic protein, oxidized starch, cationized starch, urea phosphate esterification
  • binders such as starches, starches such as hydroxyethyl etherified starch, and cellulose derivatives such as carboxymethyl cellulose, hydroxymeter cellulose, and hydroxyethyl cellulose.
  • the adhesive used for the pigment coating layer is preferably formulated with less than 5 parts by weight of starch with respect to 100 parts by weight of pigment from the viewpoint of printability.
  • starch By blending starch, the strength of the coating layer is increased.
  • the coating layer becomes stiff and the cushioning property is lowered, so that the gravure printing suitability is poor.
  • the adhesive use of a copolymer latex having a glass transition temperature of ⁇ 50 ° C. to 0 ° C. is particularly preferable because cushioning properties suitable for gravure printing can be imparted to the pigment coating layer.
  • the pigment coating layer of the present invention contains various auxiliary agents that are generally blended in pigment coating liquids, such as dispersants, thickeners, water retention agents, antifoaming agents, colorants, and printability improvers. It can be used as appropriate.
  • the apparatus for providing the coating layer on the base paper is not particularly limited.
  • a film such as a 2-roll size press coater, a gate roll coater, a blade metering size press coater, a rod metering size press coater, or a shim sizer.
  • transfer type roll coater hradette nip / blade coater, jet fountain / blade coater, and short dwell time applicator type coater, rod metering coater and curtain coater using grooved rod, plain rod, etc. instead of blade
  • a known coater such as a die coater. It is also possible to use an on-line coater to increase operational efficiency.
  • a general dryer can be used to dry the coating layer applied by the coater, and various types of dryers such as a heated hot air dryer, a heating cylinder, a gas heater dryer, an electric heater dryer, and an infrared heater dryer can be used. These can be used alone or in combination. Since the dry state affects the curl of the paper, it is preferable to use an apparatus capable of controlling the dry balance between the front and back sides in the present invention.
  • the pigment coating layer of the coated paper thus obtained can be surface-treated in order to increase the smoothness and the like.
  • the calendar process may be performed using a super calendar, a gloss calendar, a soft calendar, or the like that is usually used for smoothing the coated paper, or these may be used in combination. From the viewpoint of improving the balance between the printing surface quality and the printing workability, it is particularly preferable to perform a high temperature hot soft calendering treatment.
  • part and % are based on weight unless otherwise specified, and “part by weight” and “% by weight” respectively represent “part by weight” and “% by weight”.
  • Example 1 coated paper for printing
  • monocarbonate monocarbonate (manufactured by Kotegawa Sangyo Co., Ltd.) having an average particle diameter by laser method of 8.1 ⁇ m and 1.0 ⁇ m was used.
  • Monocarbonate having an average particle size of 8.1 ⁇ m is obtained by grinding aluminum hydroxide as described in Japanese Patent Application Laid-Open No. 2008-37664 and reacting mechanochemically with slaked lime and calcium carbonate in the presence of water. However, the grinding time of aluminum hydroxide was shortened and the time until completion of the reaction was lengthened.
  • Monocarbonate having an average particle size of 1.0 ⁇ m was synthesized by the method described in JP-A-2008-37664.
  • the pulp composition constituting the base paper was KP 40% by weight, GP 10% by weight, TMP 10% by weight and DIP 42% by weight, containing 11% by weight of light calcium carbonate (average particle size: 2.2 ⁇ m) internally added, and polyacrylamide
  • a paper stock was prepared by adding 0.03% by weight of a paper strength agent and 0.8% by weight of a sulfuric acid band as a fixing agent.
  • This stock was made at 1200 m / min with a twin wire paper machine to obtain a base paper having a basis weight of 41 g / m 2 .
  • a pigment composed of 30 parts by weight of monocarbonate having a particle size of 8.1 ⁇ m and 10 parts by weight of rutile type titanium dioxide was added to water mixed with 0.2 parts by weight of a polyacrylic acid soda dispersant, and dispersed with a scheme mixer.
  • ⁇ Preparation of coated paper> Apply the above coating solution on both sides of the base paper using a short duel type blade coater at a coating speed of 1200 m / min so that the coating amount per side becomes 3.5 g / m 2. After passing through a scuff dryer, the paper was dried with a cylinder dryer so that the moisture in the paper was 5.5%.
  • ⁇ Calendar processing> surface treatment was performed using an online soft nip calender to produce a coated paper for printing.
  • the soft calender was subjected to surface treatment under the conditions of a metal roll temperature of 150 ° C., an elastic roll with a Shore D hardness of 85, a paper feed speed of 1200 m / min, a linear pressure of 200 kN / m, and a calender nip number of 4 nips.
  • Comparative Example 1 A coated paper for printing was obtained in the same manner as in Example 1 except that 30 parts by weight of monocarbonate having an average particle diameter of 1.0 ⁇ m was used instead of monocarbonate having an average particle diameter of 8.1 ⁇ m.
  • Comparative Example 2 A coated coated paper for printing was obtained in the same manner as in Example 1 except that monocarbonate having an average particle size of 8.1 ⁇ m was not blended and fine kaolin was increased by 30 parts by weight.
  • Example 1 is the same as Example 1 except that monocarbonate having an average particle size of 8.1 ⁇ m is not blended and secondary kaolin (average particle size by laser method: 1.50 ⁇ m, manufactured by KCS / Imerys) is blended by 30 parts by weight. Thus, a coated paper for printing was obtained.
  • monocarbonate having an average particle size of 8.1 ⁇ m is not blended and secondary kaolin (average particle size by laser method: 1.50 ⁇ m, manufactured by KCS / Imerys) is blended by 30 parts by weight.
  • secondary kaolin average particle size by laser method: 1.50 ⁇ m, manufactured by KCS / Imerys
  • Comparative Example 4 A coated paper for printing was obtained in the same manner as in Example 1, except that monocarbonate having an average particle size of 8.1 ⁇ m was not blended and engineered kaolin (Contour 1500, manufactured by Imerys) was added in an amount of 30 parts by weight.
  • monocarbonate having an average particle size of 8.1 ⁇ m was not blended and engineered kaolin (Contour 1500, manufactured by Imerys) was added in an amount of 30 parts by weight.
  • Table 1 shows the evaluation results. As is apparent from Table 1, the coated paper of the present invention of Example 1 is excellent in all aspects such as opacity, stiffness (bending stiffness), back-through, dry pick strength, whiteness, and printing gloss. As a result, it was confirmed to be good as a coated paper for printing such as offset printing.
  • Example 1 (average particle size: 8.1 ⁇ m) using carbonates having different particle sizes was compared with Comparative Example 1 (average particle size: 1.0 ⁇ m), Example 1 was glossy as compared with Comparative Example 1. Although it is slightly inferior, it is confirmed that the bending stiffness and the dry pick strength are significantly high, and the coated paper for printing of the present invention is less likely to bend or pile during printing.
  • the coated coated paper of Example 1 is particularly resistant to bending stiffness (stiffness), back-through, and dry pick strength (surface) as compared to Comparative Examples 2 and 3 using kaolin, which is the same plate-like pigment as carbonate. Strength). As described above, it was confirmed that by using the carbonate having a relatively large particle diameter according to the present invention as a pigment, the rigidity and back-through of the coated paper for printing and the surface strength of the pigment coated layer can be improved.
  • Example 1 ⁇ Synthesis of monocarbonate> Similarly to Experimental Example 1, monocarbonates (manufactured by Kotegawa Sangyo Co., Ltd.) having an average particle size of 8.1 ⁇ m and 1.0 ⁇ m were used as monocarbonates. Monocarbonate having an average particle size of 8.1 ⁇ m is obtained by grinding aluminum hydroxide as described in Japanese Patent Application Laid-Open No. 2008-37664 and reacting mechanochemically with slaked lime and calcium carbonate in the presence of water. However, the grinding time of aluminum hydroxide was shortened and the time until completion of the reaction was lengthened. Monocarbonate having an average particle size of 1.0 ⁇ m was synthesized by the method described in JP-A-2008-37664.
  • ⁇ Coating Base Paper> a medium quality paper having a basis weight of 35 g / m 2 was used.
  • the pulp composition of the coated base paper is LBKP 36% by weight, NBKP 32% by weight, NTMP 22% by weight, DIP 10% by weight, light calcium carbonate (average particle size: 2.2 ⁇ m) is used as a filler, and the base paper ash content is 10 per base paper weight. % Was adjusted.
  • ⁇ Preparation of coating solution> Consisting of 30 parts by weight of calcium aluminate monocarbonate P (average particle size 8.1 ⁇ m, manufactured by Kotegawa Sangyo) and 70 parts by weight of engineered kaolin (CapimDG, average particle size 1.19 ⁇ m, manufactured by IMERYS)
  • the pigment was dispersed in water with a variety mixer to prepare an inorganic pigment slurry.
  • 10 parts of styrene / butadiene copolymer latex (glass transition temperature ⁇ 40 ° C.) is added, 0.4 part of an acrylic synthetic water retention agent and water are added, and the coating liquid has a solid content concentration of 65%.
  • styrene / butadiene copolymer latex glass transition temperature ⁇ 40 ° C.
  • ⁇ Surface Treatment> Further, soft nip calendering was performed to obtain a coated paper for gravure printing.
  • the calendar conditions were a metal roll temperature of 160 ° C., an elastic roll Shore D hardness of 85, a paper feed speed of 600 m / min, a linear pressure of 40 kg / cm, and a calendar nip number of 4 nips.
  • Example 2 coated paper was obtained in the same manner as in Example 1 except that calcium aluminate monocarbonate P was 70 parts by weight, engineered kaolin was 30 parts by weight, and the solid content concentration was 50%. .
  • Comparative Example 1 A gravure-coated paper was obtained in the same manner as in Example 1 except that calcium aluminate monocarbonate was not blended and the amount of engineered kaolin was 100 parts by weight.
  • Comparative Example 2 Except that calcium aluminate monocarbonate (V3, manufactured by Kotegawa Sangyo) with an average particle size of 1.0 ⁇ m was used instead of calcium aluminate monocarbonate (P, manufactured by Kotegawa Sangyo) with an average particle size of 8.1 ⁇ m. In the same manner as in Example 1, a coated paper for gravure printing was obtained.
  • V3 calcium aluminate monocarbonate
  • P manufactured by Kotegawa Sangyo
  • Table 2 shows the test results of the coated paper obtained in Examples and Comparative Examples.
  • the coated paper of the present invention has both high rigidity, high Clark rigidity, low missing dots, and good gravure printing suitability in both Examples 1 and 2, despite being lightweight. It was excellent.
  • the coated paper of Comparative Example 1 had low rigidity and poor gravure printing suitability. Further, the coated paper of Comparative Example 2 was inferior in printing workability due to insufficient rigidity.

Abstract

Disclosed is coated paper for printing, which has excellent stiffness and printing characteristics. Printing paper having excellent stiffness and printing characteristics can be obtained by blending calcium aluminate monocarbonate particles, which have an average particle diameter of 2-15 μm, in a pigment coating layer.

Description

印刷用塗工紙Coated paper for printing
　本発明は、剛度および印刷特性に優れた印刷用塗工紙に関する。 The present invention relates to a coated paper for printing excellent in rigidity and printing characteristics.
　近年、印刷用紙は、チラシ、カタログ、パンフレット、ダイレクトメールなどの広告・宣伝を目的とした商業印刷分野での需要が年々高まっており、その生産量が着実に伸びている。このような商業印刷分野においては、消費者に内容を視覚的に強く伝達できるよう、写真や図案が多用され、さらにカラー印刷されることが多いため、印刷品質に優れた塗工紙が要望される。 In recent years, the demand for printing paper in the commercial printing field for the purpose of advertising and promotion such as flyers, catalogs, pamphlets, and direct mails has been increasing year by year, and the production volume has been steadily increasing. In such a commercial printing field, photographs and designs are frequently used and color printing is often performed so that the contents can be transmitted visually and strongly to consumers. Therefore, coated paper with excellent print quality is desired. The
　一方で、省資源、輸送および郵送コストなどの点からコストダウンを図るため、紙のユーザーからは、印刷用塗工紙の軽量化、特に低坪量品への強い要望がある。また、商業印刷分野においては、商品情報が消費者に伝達されれば宣伝・広告媒体としての目的が達せられるため、印刷用紙自体は安価であることが求められる。 On the other hand, there is a strong demand from paper users to reduce the weight of coated paper for printing, especially for low basis weight products, in order to reduce costs in terms of resource saving, transportation and mailing costs. Also, in the commercial printing field, if product information is transmitted to consumers, the purpose as an advertising / advertisement medium can be achieved, so that the printing paper itself is required to be inexpensive.
　このような状況の中、近年、薄物コート紙や徴塗工紙の生産量の伸び率が大きい。しかし、優れた印刷品質と軽量化という二つの要望は相反するものであり、原紙坪量および塗工量を多くすると優れた印刷品質が得られるものの、高価となり、軽量・低価格の要望にそぐわない。そこで、低坪量、低塗工量のいわゆる低級グレードの塗工紙において、より上位グレードの印刷品質を備える塗工紙を実現する技術が求められていた。 Under such circumstances, the growth rate of the production volume of thin coated paper and coated paper has been large in recent years. However, the two demands of excellent print quality and light weight are contradictory. Increasing the base paper weight and coating weight provides excellent print quality, but it is expensive and does not meet the demand for light weight and low price. . Therefore, there has been a demand for a technique for realizing a coated paper having a higher grade printing quality in a so-called lower grade coated paper having a low basis weight and a low coating weight.
　一般に印刷用塗工紙に重要な品質として、白色度、不透明度、白紙光沢度、印刷光沢度がある。さらに、低塗工量の薄物塗工紙では、白紙面感や印刷面感といった品質が求められ、また、裏抜けしにくいことも重要である。裏抜け（print through）とは、印刷面の裏面（裏抜け面）に印刷面が透けて見える現象をいい、低塗工量の薄物塗工紙では、不透明度が低下するために裏抜けし易く、その改善が重要課題である。 Generally, whiteness, opacity, white paper gloss, and print gloss are important qualities for printing coated paper. Furthermore, a thin coated paper with a low coating amount is required to have a quality such as a white paper surface or a print surface, and it is also important that it is difficult to see through. Through-through (print 現象 through) is a phenomenon in which the printed surface can be seen through the printed surface (through-through surface). It is easy and the improvement is an important issue.
　また、軽量化によって印刷用紙の剛度が低下すると、印刷時に用紙の角が折れ曲がる耳折れ（ドッグイヤー）といった問題が発生することがある。耳折れが起きると印刷速度を落とさざるを得ず、印刷の作業効率が著しく低下するため、耳折れを防止することも印刷用塗工紙に強く求められる。したがって、低坪量の印刷用塗工紙において、剛度を維持することは非常に重要である。 In addition, when the stiffness of the printing paper decreases due to weight reduction, there may be a problem such as an ear fold (dog ear) in which the corner of the paper bends during printing. When the ear break occurs, the printing speed must be reduced, and the printing work efficiency is remarkably lowered. Therefore, prevention of the ear break is also strongly required for the coated paper for printing. Therefore, it is very important to maintain rigidity in the low basis weight printing coated paper.
　さらに、低坪量の印刷用塗工紙においては、印刷用紙の表面強度を確保することも大きな技術課題である。すなわち、軽量化によって塗工量が少なくなると、印刷時に必要な表面強度が確保できず、印刷時にパイリングや塗工紙表面がムケるトラブルなどが生じることがある。特にオフセット印刷では、比較的タックの強いインキが使用されるのでパイリングが生じやすく、低坪量品であっても印刷用塗工紙の表面強度を維持する必要がある。 Furthermore, for low-basis weight coated paper for printing, securing the surface strength of the printing paper is also a major technical issue. That is, if the coating amount is reduced due to weight reduction, the surface strength required at the time of printing cannot be ensured, and there may be a trouble that the surface of the coated paper or the pile is blurred at the time of printing. In offset printing, in particular, a relatively strong tack ink is used, so that it is easy to generate piling, and it is necessary to maintain the surface strength of the coated paper for printing even if it is a low basis weight product.
　一般に、塗工紙を軽量化する場合、原紙を低坪量化する方法と、塗工層を低塗工量化する方法がある。原紙を低坪量とすれば、紙厚が薄くなるため裏抜けしやくなり、剛度が低下するためオフセット輪転印刷などにおいて耳折れトラブルが発生しやすくなる。一方、塗工層を低塗工量とすれば、塗工層の原紙被覆性が悪化するために白色度や印刷面感などが悪化し、また、表面強度が低下するといった課題がある。 Generally, when reducing the weight of coated paper, there are a method of reducing the basis weight of the base paper and a method of reducing the coating amount of the coating layer. If the base paper has a low basis weight, the paper thickness will be thin, and it will be easy to see through, and the rigidity will be lowered, so that it will be easy to cause a problem with corner folding in offset rotary printing. On the other hand, if the coating layer has a low coating amount, the base paper coverage of the coating layer is deteriorated, so that the whiteness and the printing surface are deteriorated, and the surface strength is lowered.
　また、薄物塗工紙を、１０００ｍ／分以上などの高速の操業速度で製造する場合、原紙坪量を低くすると断紙が発生し、操業性が大きく低下することがある。そのため、例えば坪量５０ｇ／ｍ2以下の薄物塗工紙では、断紙を防ぐために塗工量を低くする必要が生じ、片面あたり３～７ｇ／ｍ2の薄い塗工層を設ける場合が多い。しかし、上述したように塗工量を少なくすると、白色度や印刷面感が低下してしまい、商業印刷物として十分な品質を確保することが難しくなる。 Further, when producing thin coated paper at a high operation speed such as 1000 m / min or more, if the base paper basis weight is lowered, paper breakage may occur and the operability may be greatly reduced. For this reason, for example, in the case of a thin coated paper having a basis weight of 50 g / m 2 or less, it is necessary to reduce the coating amount in order to prevent paper breakage, and a thin coating layer of 3 to 7 g / m 2 is often provided on one side. . However, as described above, when the coating amount is reduced, the whiteness and the printing surface feeling are lowered, and it becomes difficult to ensure sufficient quality as a commercial printed matter.
　このような状況の中、優れた品質を備えた軽量印刷用塗工紙を実現するため、パルプ、填料、顔料、それらの組み合わせといった材料面、操業条件などの操業面、抄紙装置や塗工装置などの装置面などから、様々な検討が加えられている。近年、カルシウムアルミネートモノカーボネート（３ＣａＯ・Ａｌ2Ｏ3・１１Ｈ2Ｏ）の安価な合成法が開発され、新規な塗工紙用顔料として、粒子径が０．５～１．５μｍのカルシウムアルミネートモノカーボネートをＡ２グレードの塗工紙に用いると、白色度および不透明度が向上することが報告されている（特許文献１）。 Under these circumstances, in order to realize lightweight coated paper with excellent quality, operational aspects such as materials such as pulp, filler, pigment, combinations thereof, operating conditions, paper making equipment and coating equipment Various studies have been made from the aspect of equipment. In recent years, an inexpensive synthesis method of calcium aluminate monocarbonate (3CaO.Al 2 O 3 .11H 2 O) has been developed, and calcium aluminum having a particle size of 0.5 to 1.5 μm is used as a new pigment for coated paper. It has been reported that whiteness and opacity are improved when Nate monocarbonate is used for A2 grade coated paper (Patent Document 1).
特開２００８－１９６０５６号公報JP 2008-196056 A
　上述したように、優れた印刷品質を有する印刷用塗工紙を開発すべく、様々な面から検討が行われ、種々の材料が提案されている。しかし、顔料塗工層を構成する顔料について白色度や不透明度に関する検討はされるものの、顔料塗工層を構成する顔料によって薄物塗工紙の剛度や表面強度を維持することに関する検討はあまりない。 As described above, various materials have been studied and various materials have been proposed in order to develop a coated paper having excellent printing quality. However, although the whiteness and opacity of the pigment constituting the pigment coating layer are studied, there are not many studies on maintaining the rigidity and surface strength of the thin coated paper by the pigment constituting the pigment coating layer. .
　このような状況に鑑み、本発明の課題は、印刷用塗工紙、特に薄物の印刷用塗工紙において、優れた剛度（こわさ）と印刷品質を備えた印刷用塗工紙を提供することである。特に本発明の課題は、高白色でありながら不透明度が高く、裏抜け等の印刷品質に優れ、また、剛度や表面強度が高い印刷用塗工紙を提供することである。 In view of such a situation, an object of the present invention is to provide a coated paper for printing having excellent rigidity (rigidity) and printing quality in a coated paper for printing, particularly a thin coated paper for printing. It is. In particular, an object of the present invention is to provide a coated paper for printing having high whiteness, high opacity, excellent print quality such as back-through, and high rigidity and surface strength.
　本発明者らは、上記課題を解決するために顔料塗工層を構成する顔料について種々検討を行った結果、平均粒子径が２～１５μｍのカルシウムアルミネートモノカーボネートを顔料塗工層の顔料として配合すると、剛度が高く、印刷品質に優れた印刷用塗工紙が得られることを見出し、本発明を完成させた。 As a result of various studies on the pigments constituting the pigment coating layer in order to solve the above problems, the present inventors have determined that calcium aluminate monocarbonate having an average particle diameter of 2 to 15 μm is used as the pigment of the pigment coating layer. When blended, it was found that a coated paper for printing with high rigidity and excellent print quality was obtained, and the present invention was completed.
　本発明は、これに限定されるものではないが、以下の発明に関する。
（１）原紙と顔料塗工層を有する印刷用塗工紙であって、顔料塗工層が、平均粒子径が２～１５μｍであるカルシウムアルミネートモノカーボネートを含んでなる、上記印刷用塗工紙。
（２）　前記カルシウムアルミネートモノカーボネートの平均粒子径が２～１０μｍである、（１）に記載の塗工紙。
（３）　坪量が３０～６０ｇ／ｍ2である、（１）または（２）に記載の塗工紙。
（４）　グラビア印刷用である、（１）または（２）に記載の塗工紙。 Although this invention is not limited to this, It is related with the following invention.
(1) A printing coated paper having a base paper and a pigment coating layer, wherein the pigment coating layer comprises calcium aluminate monocarbonate having an average particle diameter of 2 to 15 μm. paper.
(2) The coated paper according to (1), wherein the calcium aluminate monocarbonate has an average particle size of 2 to 10 μm.
(3) The coated paper according to (1) or (2), wherein the basis weight is 30 to 60 g / m 2 .
(4) The coated paper according to (1) or (2), which is for gravure printing.
　本発明によれば、優れた剛度と印刷品質を備えた印刷用塗工紙を得ることができる。特に本発明の印刷用塗工紙は、低坪量でありながら、剛度や表面強度が高く、白色度、不透明度、裏抜けなどの印刷品質に優れる。 According to the present invention, a coated paper for printing having excellent rigidity and printing quality can be obtained. In particular, the coated paper for printing of the present invention has high rigidity and surface strength while having a low basis weight, and is excellent in printing quality such as whiteness, opacity, and back-through.
　本発明は、原紙と顔料塗工層を有する印刷用塗工紙に関し、顔料塗工層を構成する顔料として平均粒子径が２～１５μｍのカルシウムアルミネートモノカーボネートを用いる。 The present invention relates to a coated paper for printing having a base paper and a pigment coating layer, and uses calcium aluminate monocarbonate having an average particle diameter of 2 to 15 μm as a pigment constituting the pigment coating layer.
　印刷用塗工紙
　本発明の印刷用塗工紙は、各種印刷用途に好適に用いることができ、例えば、オフセット印刷などの平版印刷、グラビア印刷などの凹版印刷、凸版印刷などの印刷方式で使用することができる。本発明の印刷用塗工紙は、目的に応じて、各種の塗工紙に用いることができるが、剛度や裏抜けに優れるため、Ａ３コート紙などの低坪量印刷用塗工紙として好適であり、チラシ、カタログなどの商業印刷物に用いられる印刷用塗工紙として特に好適である。 Coated paper for printing The coated paper for printing of the present invention can be suitably used for various printing applications. For example, it is used in printing systems such as planographic printing such as offset printing, intaglio printing such as gravure printing, and relief printing. can do. The printing coated paper of the present invention can be used for various coated papers depending on the purpose, but is suitable as a low basis weight printing coated paper such as A3 coated paper because it is excellent in rigidity and back-through. It is particularly suitable as a coated paper for printing used in commercial printed materials such as leaflets and catalogs.
　本発明の印刷用塗工紙の坪量は特に限定されないが、本発明によれば低坪量でも高い剛度と表面強度が得られるため、３０～６０ｇ／ｍ2が好ましく、３０～５０ｇ／ｍ2がより好ましく、４０～５０ｇ／ｍ2がさらに好ましい。また、本発明の印刷用塗工紙のＩＳＯ曲げこわさは、特に限定されず、印刷機や印刷速度などの使用状況などに応じて適宜決定することができるが、１つの態様として、マシン方向（Machine Direction：ＭＤ）における曲げこわさは、３０～８０μＮ・ｍ2／ｍが好ましく、５０～８０μＮ・ｍ2／ｍがより好ましく、６０～７０μＮ・ｍ2／ｍがさらに好ましい。 The basis weight of the coated paper for printing of the present invention is not particularly limited, but according to the present invention, high rigidity and surface strength can be obtained even at a low basis weight, and therefore 30 to 60 g / m 2 is preferable, and 30 to 50 g / m 2 is preferable. 2 is more preferable, and 40 to 50 g / m 2 is more preferable. Moreover, the ISO bending stiffness of the coated paper for printing of the present invention is not particularly limited, and can be determined as appropriate according to usage conditions such as a printing press and a printing speed. As one aspect, the machine direction ( Machine Direction: bending in MD) stiffness is preferably 30 ~ 80μN · m 2 / m , more preferably 50 ~ 80μN · m 2 / m , more preferably 60 ~ 70μN · m 2 / m .
　本発明の印刷用塗工紙は、特に低坪量の場合に、優れたグラビア印刷特性や剛度といった本発明の優位性が高くなるため、グラビア印刷用紙として好適であり、坪量が３５～２００ｇ／ｍ2であることが好ましく、３５～１００ｇ／ｍ2がより好ましく、３５～７０ｇ／ｍ2がさらに好ましく、３５～５０ｇ／ｍ2いう低坪量においてもグラビア適性のみならず印刷作業性が良好であるという本発明の効果を享受することができる。また、本発明の印刷用塗工紙は剛度が高いため、グラビア印刷における通紙性及び印面品質が良好になる。本発明のグラビア印刷用塗工紙の剛度は、坪量や塗工量によって様々であるが、低坪量であっても印刷作業性等に優れるように、ＭＤ方向のクラークこわさが２０ｃｍ3／１００以上とすることが好ましい。 The coated paper for printing of the present invention is suitable as a gravure printing paper because the superiority of the present invention, such as excellent gravure printing properties and rigidity, is obtained particularly when the basis weight is low, and the basis weight is 35 to 200 g. / M 2 is preferable, 35 to 100 g / m 2 is more preferable, 35 to 70 g / m 2 is more preferable, and not only gravure suitability but also printing workability at a low basis weight of 35 to 50 g / m 2. The effect of the present invention that it is favorable can be enjoyed. Moreover, since the coated paper for printing of the present invention has high rigidity, the paper passing property and the printing surface quality in gravure printing are improved. Stiffness gravure coated printing paper of the present invention is different depending the basis weight and coating weight, as excellent low basis weight in a even printing workability, Clark stiffness in the MD direction is 20 cm 3 / 100 or more is preferable.
　カルシウムアルミネートモノカーボネート
　本発明の印刷用塗工紙は、平均粒子径が２～１５μｍのカルシウムアルミネートモノカーボネートを顔料塗工層に含む。カルシウムアルミネートモノカーボネート（以下、モノカーボネートともいう）は、３ＣａＯ・Ａｌ2Ｏ3の組成を有する結晶性物質であり、水分子と水和した状態で得られる。モノカーボネートは、層状構造を有し、カオリンなどと同様の六角板状の一次粒子からなり、一般に消石灰と水酸化アルミニウムから合成される。 Calcium aluminate monocarbonate The coated paper for printing of the present invention contains calcium aluminate monocarbonate having an average particle diameter of 2 to 15 μm in the pigment coating layer. Calcium aluminate monocarbonate (hereinafter also referred to as monocarbonate) is a crystalline substance having a composition of 3CaO · Al 2 O 3 and is obtained in a state of being hydrated with water molecules. Monocarbonate has a layered structure, is composed of hexagonal plate-like primary particles similar to kaolin, and is generally synthesized from slaked lime and aluminum hydroxide.
　本発明のカルシウムアルミネートモノカーボネートの平均粒径（体積基準）は２～１５μｍであり、このような粒径のモノカーボネートを用いることによって、優れた剛度と表面強度を有し、印刷適性にも優れた印刷用塗工紙を得ることができる。モノカーボネートの平均粒径が２μｍ未満であると、顔料塗工層の光沢性は良化するものの、剛度や表面強度が低下する。一方、モノカーボネートの平均粒径が１５μｍを超えると、顔料塗工層の平滑性が低下し、良好な印刷面を得ることが難しくなる。白紙光沢度や印刷光沢度を考慮すると、本発明のカルシウムアルミネートモノカーボネートの平均粒径（体積基準）は２～１０μｍが好ましく、５～１０μｍがより好ましい。ここで、本発明で規定する粒径とは、レーザー回折法によって測定した体積基準の平均粒子径であり、例えば、MALVERN Instruments社のMastersizerなどのレーザー回折式粒度分布測定器などを用いて測定することができる。その他、顔料の粒径は、沈降法によって測定することもでき、例えば、Micromeritics社のSedigraphなどを用いることができる。 The average particle size (volume basis) of the calcium aluminate monocarbonate of the present invention is 2 to 15 μm. By using a monocarbonate having such a particle size, the calcium aluminate monocarbonate has excellent rigidity and surface strength, and is also suitable for printing. Excellent coated paper for printing can be obtained. When the average particle size of monocarbonate is less than 2 μm, the glossiness of the pigment coating layer is improved, but the rigidity and surface strength are lowered. On the other hand, when the average particle diameter of monocarbonate exceeds 15 μm, the smoothness of the pigment coating layer is lowered, and it becomes difficult to obtain a good printing surface. In consideration of blank paper gloss and printing gloss, the average particle size (volume basis) of the calcium aluminate monocarbonate of the present invention is preferably 2 to 10 μm, more preferably 5 to 10 μm. Here, the particle diameter defined in the present invention is a volume-based average particle diameter measured by a laser diffraction method, and is measured using, for example, a laser diffraction particle size distribution measuring instrument such as MALVERN® Instruments Mastersizer. be able to. In addition, the particle diameter of the pigment can also be measured by a sedimentation method, and for example, Sedigraph manufactured by Micromeritics can be used.
　本発明のカルシウムアルミネートモノカーボネートの配合量は、用途などに応じて適宜決定すればよく、特に制限されないが、顔料塗工層を構成する顔料１００重量部のうち５重量部以上であることが好ましく、カルシウムアルミニウムモノカーボネートのみを顔料として用いて顔料塗工層を形成させることもできる。好ましい態様において、カルシウムアルミネートモノカーボネートの配合量は１０～５０重量部であり、より好ましくは１０～４０重量部である。このような量であると顔料塗工時の作業性などに悪影響を与えることなく、剛度や表面強度などに優れた本発明の印刷用塗工紙を得ることができる。 The blending amount of the calcium aluminate monocarbonate of the present invention may be appropriately determined according to the use and the like, and is not particularly limited, but may be 5 parts by weight or more out of 100 parts by weight of the pigment constituting the pigment coating layer. Preferably, the pigment coating layer can be formed using only calcium aluminum monocarbonate as a pigment. In a preferred embodiment, the amount of calcium aluminate monocarbonate is 10 to 50 parts by weight, more preferably 10 to 40 parts by weight. With such an amount, the coated paper for printing of the present invention having excellent rigidity and surface strength can be obtained without adversely affecting workability during pigment coating.
　本発明において平均粒子径が２～１５μｍのカルシウムアルミネートモノカーボネートを顔料塗工層に配合すると、優れた剛度や表面強度を有し、印刷品質に優れた印刷用塗工紙が得られる理由の詳細は明らかでなく、本発明はこれに拘束されるものではないが、本発明のカルシウムアルミネートモノカーボネートはカオリンや炭酸カルシウムなどの顔料と比べて比重が低いため、カルシウムアルミネートモノカーボネートを配合すると嵩高な顔料塗工層が形成されるため、剛度が向上するものと推測される。また、本発明のカルシウムアルミネートモノカーボネートは比較的規則的な板状形状を有しており、このような顔料を顔料塗工層に配合することによって塗工層の表面強度が向上し、また、平均粒子径を２μｍ以上とすることによって顔料塗工層から顔料が脱落しにくくなり、印刷時のパイリングやムケが少なくなるものと推測される。 In the present invention, when calcium aluminate monocarbonate having an average particle size of 2 to 15 μm is blended in the pigment coating layer, a coated paper for printing having excellent rigidity and surface strength and excellent printing quality can be obtained. Details are not clear, and the present invention is not limited to this, but the calcium aluminate monocarbonate of the present invention has a lower specific gravity than pigments such as kaolin and calcium carbonate, so it contains calcium aluminate monocarbonate. Then, since a bulky pigment coating layer is formed, it is estimated that the rigidity is improved. The calcium aluminate monocarbonate of the present invention has a relatively regular plate shape, and the surface strength of the coating layer is improved by blending such a pigment into the pigment coating layer. When the average particle size is 2 μm or more, it is presumed that the pigment is less likely to drop off from the pigment coating layer, and that piling and smearing during printing are reduced.
　本発明のカルシウムアルミニウムモノカーボネートは、市販品を用いても、合成したものを用いてもよい。モノカーボネートは、サチンホワイト（３ＣａＯ・Ａｌ2Ｏ3・３ＣａＳＯ4）と同様にセメント硬化物中に生成することが知られている。粒径形状は、モノカーボネートが層状構造を有する六角板状であるのに対し、サチンホワイトは針状であり、塗工紙用顔料として用いると紙面上で平坦に配向しやすいとされる。カルシウムアルミニウムモノカーボネートの合成は、公知の方法により行うことができ、例えば、無水カルシウムアルミネートを水中で炭酸カルシウムと反応させる方法（大門他、「3CaO・Al2O3-CaSO4・2H2O-CaCO3-Na2SO4-H2O系水和物の合成」『無機マテリアル』１９６頁、vol.4、１９９７年）、水酸化アルミニウムを摩砕処理などによりメカノケミカル的に消石灰および炭酸カルシウムと水の存在下で反応させる方法（特開２００８－３７６６４号公報参照）などを挙げることができる。なお、本発明に用いられる粒子径２μｍ～１５μｍのモノカーボネートは、特開２００８－３７６６４号公報記載の方法で合成する場合、水酸化アルミニウムの摩砕時間を短くし反応終了までの時間を長くすることによって合成することができる。 The calcium aluminum monocarbonate of the present invention may be a commercially available product or a synthesized product. It is known that monocarbonate is formed in a hardened cement material in the same manner as satin white (3CaO.Al 2 O 3 .3CaSO 4 ). The particle size is a hexagonal plate with monocarbonate having a layered structure, whereas satin white has a needle shape, and when used as a pigment for coated paper, it tends to be oriented flat on the paper surface. Calcium aluminum monocarbonate can be synthesized by a known method, for example, a method in which anhydrous calcium aluminate is reacted with calcium carbonate in water (Damon et al., “3CaO · Al 2 O 3 —CaSO 4 · 2H 2 O -CaCO 3 —Na 2 SO 4 —H 2 O Hydrate ”,“ Inorganic Materials ”, page 196, vol.4, 1997), mechanochemically slaked lime and carbonate by grinding aluminum hydroxide Examples include a method of reacting calcium and water in the presence of water (see JP 2008-37664 A). When the monocarbonate having a particle size of 2 μm to 15 μm used in the present invention is synthesized by the method described in Japanese Patent Application Laid-Open No. 2008-37664, the grinding time of aluminum hydroxide is shortened and the time until completion of the reaction is lengthened. Can be synthesized.
　原紙
　本発明に使用する原紙は特に制限されず、上質紙や中質紙、再生紙等の一般的な用紙を使用することができ、酸性紙であっても中性紙であってもよい。本発明の原紙の坪量は特に制限されないが、カーボネートを配合した本発明の塗工紙は裏抜けしにくく、表面強度も高いため、２５～５５ｇ／ｍ2が好ましく、３０～５０ｇ／ｍ2がより好ましく、３５～４５ｇ／ｍ2がさらに好ましい。 Base Paper The base paper used in the present invention is not particularly limited, and general paper such as high-quality paper, medium-quality paper, and recycled paper can be used, and it may be acid paper or neutral paper. The basis weight of the base paper of the present invention is not particularly limited, but the coated paper of the present invention blended with carbonate is difficult to see through and has high surface strength, and is preferably 25 to 55 g / m 2 , preferably 30 to 50 g / m 2. Is more preferable, and 35 to 45 g / m 2 is more preferable.
　本発明の原紙に使用するパルプは、特に限定されるものではないが、例えば、機械パルプ(ＭＰ)、再生パルプ、広葉樹クラフトパルプ（ＬＫＰ）、針葉樹クラフトパルプ（ＮＫＰ）など、印刷用紙の抄紙原料として一般的に使用されているものを好適に使用することができ、適宜、これらの１種類または２種類以上を配合して使用される。機械パルプとしては、砕木パルプ(ＧＰ)、リファイナー砕木パルプ(ＲＧＰ)、サーモメカニカルパルプ(ＴＭＰ)、ケミサーモメカニカルパルプ(ＣＴＭＰ)、ケミグランドパルプ(ＣＧＰ)、セミケミカルパルプ(ＳＣＰ)などが挙げられる。その他にも、一般的な木材パルプに加えて、リンターパルプ、麻、バガス、ケナフ、エスパルト草、ワラなどの非木材パルプ、レーヨン、アセテートなどの半合成繊維、ポリオレフィン、ポリアミド、ポリエステルなどの合成繊維などを使用することができる。 The pulp used for the base paper of the present invention is not particularly limited, but, for example, raw materials for printing paper such as mechanical pulp (MP), regenerated pulp, hardwood kraft pulp (LKP), conifer kraft pulp (NKP), etc. In general, those commonly used can be suitably used, and one or two or more of these can be used as appropriate. Examples of the mechanical pulp include groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemiground pulp (CGP), semi-chemical pulp (SCP), and the like. . In addition to general wood pulp, non-wood pulp such as linter pulp, hemp, bagasse, kenaf, esparto grass, and straw, semi-synthetic fibers such as rayon and acetate, synthetic fibers such as polyolefin, polyamide, and polyester Etc. can be used.
　本発明の原紙に使用する填料は、特に限定されるものではないが、例えば、重質炭酸カルシウムや軽質炭酸カルシウムなどの炭酸カルシウム、酸化チタン、クレー、シリカ、タルク、カオリン、焼成カオリン、デラミカオリン、炭酸マグネシウム、炭酸バリウム、酸化亜鉛、酸化珪素、非晶質シリカ、水酸化アルミニウム、水酸化カルシウム、水酸化マグネシウム、水酸化亜鉛、酸化チタン、ベントナイトなどの無機填料；尿素－ホルマリン樹脂、ポリスチレン樹脂、メラミン樹脂、フェノール樹脂、微小中空粒子等の有機填料；を単独または適宜２種類以上を組み合わせて使用することができる。また、製紙スラッジや脱墨フロス等を原料とした再生填料も使用することができる。特に、本発明においては、安価でかつ光学特性に優れていることから、炭酸カルシウムを填料として使用することが好ましい。また、炭酸カルシウム－シリカ複合物（例えば、特開２００３－２１２５３９号公報あるいは特開２００５－２１９９４５号公報等に記載の軽質炭酸カルシウム－シリカ複合物）などの複合填料も使用可能である。酸性抄紙では、前記中性抄紙で使用する填料から、酸溶解性のものを除いた填料が使用され、その単独または適宜２種類以上を組み合わせて使用される。填料の配合量としては、原紙総重量あたり、２～２５重量％含有することが好ましい。グラビア印刷用紙の場合は、３～１５重量％含有することがより好ましい。 The filler used in the base paper of the present invention is not particularly limited. For example, calcium carbonate such as heavy calcium carbonate and light calcium carbonate, titanium oxide, clay, silica, talc, kaolin, calcined kaolin, deramikaolin. , Magnesium carbonate, barium carbonate, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, titanium oxide, bentonite and other inorganic fillers; urea-formalin resin, polystyrene resin , Organic fillers such as melamine resin, phenol resin, and fine hollow particles can be used alone or in appropriate combination of two or more. In addition, recycled fillers made from papermaking sludge, deinking floss, etc. can also be used. In particular, in the present invention, it is preferable to use calcium carbonate as a filler because it is inexpensive and excellent in optical properties. A composite filler such as a calcium carbonate-silica composite (for example, a light calcium carbonate-silica composite described in Japanese Patent Application Laid-Open No. 2003-212539 or Japanese Patent Application Laid-Open No. 2005-219945) can also be used. In acidic papermaking, a filler obtained by removing acid-soluble ones from the filler used in the neutral papermaking is used, and used alone or in appropriate combination of two or more. The blending amount of the filler is preferably 2 to 25% by weight based on the total weight of the base paper. In the case of gravure printing paper, the content is more preferably 3 to 15% by weight.
　本発明においては、パルプ、填料の他に、原紙の製造に一般的に使用される製紙用薬品を適宜使用することができる。例えば、本発明において内添サイズ剤として、ロジン系サイズ剤、合成サイズ剤、石油樹脂系サイズ剤、中性サイズ剤などのサイズ剤を使用することができる。その他にも、紙力増強剤、歩留剤、濾水性向上剤、凝結剤、硫酸バンド、ベントナイト、シリカ、染料、ｐＨ制御剤、消泡剤、ピッチコントロール剤、紫外線防止剤、退色防止剤、スライムコントロール剤などの抄紙用内添薬品を、目的に応じて適宜添加することができる。 In the present invention, in addition to pulp and filler, papermaking chemicals generally used for the production of base paper can be used as appropriate. For example, sizing agents such as rosin-based sizing agents, synthetic sizing agents, petroleum resin-based sizing agents, and neutral sizing agents can be used as the internal sizing agent in the present invention. In addition, paper strength enhancer, retention agent, freeness improver, coagulant, sulfuric acid band, bentonite, silica, dye, pH control agent, antifoaming agent, pitch control agent, UV inhibitor, anti-fading agent, An internal additive for papermaking such as a slime control agent can be appropriately added depending on the purpose.
　また、原紙上に、澱粉やポリビニルアルコール（ＰＶＡ）、ポリアクリルアミド（ＰＡＭ）などの接着剤を予備塗工してから、後述の顔料塗工層を設けることもできる。予備塗工は、例えば、サイズプレス、ゲートロールコーター、プレメタリングサイズプレスなどの装置を用いて行うことができる。 Further, after applying an adhesive such as starch, polyvinyl alcohol (PVA) or polyacrylamide (PAM) on the base paper, a pigment coating layer described later can be provided. The preliminary coating can be performed using an apparatus such as a size press, a gate roll coater, or a pre-metering size press.
　顔料塗工層
　本発明の印刷用塗工紙は、原紙上に顔料塗工層を備える。本発明の顔料塗工層は、顔料とバインダーを含んでなり、公知の方法により原紙上に設けることができる。本発明の顔料塗工層は、原紙の片面または両面に設けられ、単層であっても２層以上設けてもよい。 Pigment coating layer The coated paper for printing of the present invention comprises a pigment coating layer on a base paper. The pigment coating layer of the present invention comprises a pigment and a binder, and can be provided on the base paper by a known method. The pigment coating layer of the present invention is provided on one side or both sides of the base paper, and may be a single layer or two or more layers.
　本発明において、顔料塗工層の塗工量は特に制限されないが、本発明のカーボネートは低塗工量においてもその効果を発揮することができるため、片面あたり２～１０ｇ／ｍ2であることが好ましく、２～８ｇ／ｍ2であることがより好ましく、３～６ｇ／ｍ2であることがさらに好ましい。またグラビア印刷用紙の場合は、片面あたり２～３５ｇ／ｍ2であることが好ましく、３～２０ｇ／ｍ2であることがより好ましく、３～１０ｇ／ｍ2であることがさらに好ましい。 In the present invention, the coating amount of the pigment coating layer is not particularly limited, but since the carbonate of the present invention can exert its effect even at a low coating amount, it should be 2 to 10 g / m 2 per side. It is preferably 2 to 8 g / m 2 , more preferably 3 to 6 g / m 2 . In the case of gravure printing paper, it is preferably 2 to 35 g / m 2 per side, more preferably 3 to 20 g / m 2 , and further preferably 3 to 10 g / m 2 .
　本発明の印刷用塗工紙は、平均粒子径が２～１５μｍのカーボネートが顔料塗工層に含まれていれば、他の顔料を含んでいてもよい。本発明の塗工層に用いる顔料としては、これに限定されないが、例えば、カオリン、クレー、デラミネーテッドクレー、重質炭酸カルシウム、軽質炭酸カルシウム、タルク、二酸化チタン、硫酸バリウム、硫酸カルシウム、酸化亜鉛、ケイ酸、ケイ酸塩、コロイダルシリカ、サチンホワイト等の無機顔料を、モノカーボネートと併用することができる。 The coated paper for printing of the present invention may contain other pigments as long as carbonate having an average particle diameter of 2 to 15 μm is contained in the pigment coating layer. Examples of the pigment used in the coating layer of the present invention include, but are not limited to, kaolin, clay, delaminated clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, calcium sulfate, and oxidation. Inorganic pigments such as zinc, silicic acid, silicate, colloidal silica, and satin white can be used in combination with monocarbonate.
　一般に顔料塗工層には、顔料の他に各種バインダーが使用されるが、本発明においても種々のバインダーを使用することができる。本発明の塗工層に用いる接着剤としては、例えば、スチレン・ブタジェン系、スチレン・アクリル系、エチレン・酢酸ビニル系、ブタジェン・メチルメタクリレート系、酢酸ビニル・ブチルアクリレート系等の各種共重合体、あるいはポリビニルアルコール、無水マレイン酸共重合体、アクリル酸・メチルメタクリレート系共重合体等の合成接着剤、カゼイン、大豆タンパク、合成タンパクなどのタンパク質類、酸化澱粉、カチオン化澱粉、尿素リン酸エステル化澱粉、ヒドロキシェチルェーテル化澱粉などの澱粉類、カルボキシメチルセルロース、ヒドロキシメテルセルロース、ヒドロキシェチルセルロース等のセルロース誘導体などのバインダーから、１種以上を適宜選択して使用することができる。接着剤の配合量としては、顔料１００重量部に対して５～５０重量部程度であり、好ましくは１０～３０重量部である。 Generally, various binders are used in the pigment coating layer in addition to the pigment, but various binders can also be used in the present invention. Examples of the adhesive used in the coating layer of the present invention include, for example, various copolymers such as styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, vinyl acetate / butyl acrylate, Or synthetic adhesives such as polyvinyl alcohol, maleic anhydride copolymer, acrylic acid / methyl methacrylate copolymer, proteins such as casein, soy protein, synthetic protein, oxidized starch, cationized starch, urea phosphate esterification One or more types can be appropriately selected and used from binders such as starches, starches such as hydroxyethyl etherified starch, and cellulose derivatives such as carboxymethyl cellulose, hydroxymeter cellulose, and hydroxyethyl cellulose. The blending amount of the adhesive is about 5 to 50 parts by weight, preferably 10 to 30 parts by weight with respect to 100 parts by weight of the pigment.
　グラビア印刷用塗工紙の場合、顔料塗工層に用いる接着剤としては、印刷適性の点から、顔料１００重量部に対して５重量部未満の澱粉を配合することが好ましい。澱粉を配合することによって塗工層の強度は増すが、顔料１００重量部に対して５重量部以上配合した場合、塗工層が堅くなりクッション性が低下するため、グラビア印刷適性は劣る。また、接着剤としては、ガラス転移温度が－５０℃～０℃の共重合体ラテックスを使用すると、グラビア印刷に適したクッション性を顔料塗工層に付与することができ、特に好適である。 In the case of coated paper for gravure printing, the adhesive used for the pigment coating layer is preferably formulated with less than 5 parts by weight of starch with respect to 100 parts by weight of pigment from the viewpoint of printability. By blending starch, the strength of the coating layer is increased. However, when blending 5 parts by weight or more with respect to 100 parts by weight of the pigment, the coating layer becomes stiff and the cushioning property is lowered, so that the gravure printing suitability is poor. As the adhesive, use of a copolymer latex having a glass transition temperature of −50 ° C. to 0 ° C. is particularly preferable because cushioning properties suitable for gravure printing can be imparted to the pigment coating layer.
　また、本発明の顔料塗工層には、分散剤、増粘剤、保水剤、消泡剤、着色剤、印刷適性向上剤など、顔料塗工液に一般的に配合される各種助剤を適宜使用することができる。 In addition, the pigment coating layer of the present invention contains various auxiliary agents that are generally blended in pigment coating liquids, such as dispersants, thickeners, water retention agents, antifoaming agents, colorants, and printability improvers. It can be used as appropriate.
　本発明において、原紙上に塗工層を設ける装置は特に制限されず、例えば、２ロールサイズプレスコータやゲートロールコータ及びブレードメタリングサイズプレスコータ、ロッドメタリングサイズプレスコータ、及びシムサイザー等のフィルム転写型ロールコータ、フラデットニップ／ブレードコータ、ジェットファウンテン／ブレードコータ、及びショートドウェルタイムアプルケート式コータの他、ブレードの替わりにグルーブドロッド、プレーンロッド等を用いたロッドメタリングコータ、カーテンコータ、及びダイコータ等の公知のコータを用いて塗工することができる。また、操業効率を高めるため、オンラインのコーターを用いることも可能である。 In the present invention, the apparatus for providing the coating layer on the base paper is not particularly limited. For example, a film such as a 2-roll size press coater, a gate roll coater, a blade metering size press coater, a rod metering size press coater, or a shim sizer. In addition to transfer type roll coater, hradette nip / blade coater, jet fountain / blade coater, and short dwell time applicator type coater, rod metering coater and curtain coater using grooved rod, plain rod, etc. instead of blade , And a known coater such as a die coater. It is also possible to use an on-line coater to increase operational efficiency.
　コーターによって塗工された塗工層の乾燥には、一般的なドライヤを用いることができ、加熱熱風エアドライヤ、加熱シリンダ、ガスヒータードライヤ、電気ヒータードライヤ、赤外線ヒータードライヤ等、各種の方式のドライヤを、単独であるいは組み合せて用いることができる。乾燥状態が用紙のカールに影響を及ぼすため、本発明においては表裏の乾燥バランスをコントロールすることのできる装置を用いることが好ましい。 A general dryer can be used to dry the coating layer applied by the coater, and various types of dryers such as a heated hot air dryer, a heating cylinder, a gas heater dryer, an electric heater dryer, and an infrared heater dryer can be used. These can be used alone or in combination. Since the dry state affects the curl of the paper, it is preferable to use an apparatus capable of controlling the dry balance between the front and back sides in the present invention.
　本発明においては、このようにして得られた塗工紙の顔料塗工層を、平滑度などを高めるため表面処理することも可能である。カレンダー処理は、コート紙の平滑化処理に通常使用されるスーパーカレンダー、グロスカレンダー、ソフトカレンダー等を用いて行なえばよく、また、これらを併用してもよい。印面品質及び印刷作業性のバランスを良好にする観点から、特に高温ホットソフトカレンダー処理することが好ましい。 In the present invention, the pigment coating layer of the coated paper thus obtained can be surface-treated in order to increase the smoothness and the like. The calendar process may be performed using a super calendar, a gloss calendar, a soft calendar, or the like that is usually used for smoothing the coated paper, or these may be used in combination. From the viewpoint of improving the balance between the printing surface quality and the printing workability, it is particularly preferable to perform a high temperature hot soft calendering treatment.
　以下に実施例をあげて、本発明をより具体的に説明するが、本発明はこれらによって限定されるものではない。なお、本明細書において部および％は、特記しない限り重量基準であり、重量部および重量％は、それぞれ固形分重量部および固形分重量％を示す。 Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the present specification, “part” and “%” are based on weight unless otherwise specified, and “part by weight” and “% by weight” respectively represent “part by weight” and “% by weight”.
　評価方法
　本発明における各種評価方法の詳細は以下のとおりである。
（１）平均粒子径
　Mastersizer2000（MALVERN Instruments社製、レーザー法）及びSedigraph（Micromeritics社製、沈降法）により測定した。
（２）坪量・紙厚
　坪量はJIS P8124に準じて測定し、紙厚はJIS P8118に準じて測定した。
（３）ＩＳＯ曲げこわさ
　ISO 2493に準じて、L&W Bending Tester（Lorentzen＆Wettre社製）で、曲げ角度が１５度の曲げこわさを測定した。
（４）ＩＳＯ白色度
　拡散照明方式によるＩＳＯ白色度（JIS P8148）を測定した。
（５）ＩＳＯ不透明度
　ＩＳＯ不透明度（JIS P8149）を測定した。
（６）印刷光沢度
　ローランド枚葉印刷機（４色）を用いて、枚葉印刷用インキ（東洋インキ製）を使用して印刷速度８０００枚／時で墨→藍→紅→黄の順で印刷し、得られた印刷物（藍単色、藍紅２色、藍紅黄３色ベタ印刷部）の表面をＪＩＳ　Ｐ－８１４２に従い角度７５度にてそれぞれ印刷光沢度を測定し、その平均値を算出した。
（７）裏抜け
　ローランド枚葉印刷機（４色）を用いて、枚葉印刷用インキ（東洋インキ製）を使用して印刷速度８０００枚／時で墨→藍→紅→黄の順で印刷し、得られた印刷物の裏抜け具合を目視評価した。評価基準は以下のとおりである。
◎＝非常に良好、○＝良好、△＝やや劣る、×＝劣る
（８）ドライピック表面強度評価
　ローランド社製の枚葉印刷機Ｒ２０２にてＡ３サイズのサンプルに藍色インキを単色ベタ印刷後、表面に現れるパルプ繊維の剥離数を目視で評価した。評価基準は以下のとおりである。
・○：パルプ繊維剥離の発生がほとんど認められなかった
・△：パルプ繊維剥離が少量発生していた
・×：パルプ繊維剥離が多く発生していた Evaluation Method Details of various evaluation methods in the present invention are as follows.
(1) Average particle diameter It measured by Mastersizer2000 (the product made by MALVERN Instruments, the laser method) and Sedigraph (the product made by Micromeritics, the precipitation method).
(2) Basis weight / paper thickness Basis weight was measured according to JIS P8124, and paper thickness was measured according to JIS P8118.
(3) ISO bending stiffness According to ISO 2493, a bending stiffness with a bending angle of 15 degrees was measured with an L & W Bending Tester (manufactured by Lorentzen & Wettre).
(4) ISO whiteness ISO whiteness (JIS P8148) by a diffuse illumination method was measured.
(5) ISO opacity ISO opacity (JIS P8149) was measured.
(6) Glossiness of printing Using a Roland sheet-fed printing press (4 colors) and using a sheet-fed printing ink (manufactured by Toyo Ink) at a printing speed of 8000 sheets / hour in the order of black, indigo, red, yellow Print and measure the surface gloss of the resulting printed material (indigo single color, indigo red 2 color, indigo red 3 color solid print part) according to JIS P-8142 at an angle of 75 degrees. Calculated.
(7) Back-through Using a Roland sheet-fed printing press (4 colors), printing is performed in the order of ink, indigo, red, yellow using a sheet-fed printing ink (manufactured by Toyo Ink) at a printing speed of 8000 sheets / hour. Then, the degree of through-through of the obtained printed matter was visually evaluated. The evaluation criteria are as follows.
◎ = Very good, ○ = Good, Δ = Slightly inferior, X = Inferior (8) Evaluation of dry pick surface strength After single-color solid printing of indigo ink on A3-sized sample on a sheet-fed printing press R202 manufactured by Roland The number of peeled pulp fibers appearing on the surface was visually evaluated. The evaluation criteria are as follows.
・ ○: Almost no pulp fiber peeling occurred. Δ: A little pulp fiber peeling occurred. ×: Many pulp fiber peeling occurred.
　［実験例１：印刷用塗工紙］
　実施例１
　＜モノカーボネートの合成＞
　モノカーボネートとして、レーザー法による平均粒子径が８．１μｍと１．０μｍのモノカーボネート（古手川産業製）を使用した。平均粒子径８．１μｍのモノカーボネートは、特開２００８－３７６６４号公報に記載されたように水酸化アルミニウムを摩砕処理し、メカノケミカル的に消石灰および炭酸カルシウムと水の存在下で反応させることによって合成したが、水酸化アルミニウムの摩砕時間を短くし、反応終了までの時間を長くした。平均粒子径１．０μｍのモノカーボネートは特開２００８－３７６６４号公報記載の方法で合成された。 [Experimental example 1: coated paper for printing]
Example 1
<Synthesis of monocarbonate>
As the monocarbonate, monocarbonate (manufactured by Kotegawa Sangyo Co., Ltd.) having an average particle diameter by laser method of 8.1 μm and 1.0 μm was used. Monocarbonate having an average particle size of 8.1 μm is obtained by grinding aluminum hydroxide as described in Japanese Patent Application Laid-Open No. 2008-37664 and reacting mechanochemically with slaked lime and calcium carbonate in the presence of water. However, the grinding time of aluminum hydroxide was shortened and the time until completion of the reaction was lengthened. Monocarbonate having an average particle size of 1.0 μm was synthesized by the method described in JP-A-2008-37664.
　＜原紙の製造＞
　原紙を構成するパルプ組成を、ＫＰ４０重量％、ＧＰ１０重量％、ＴＭＰ１０重量％及びＤＩＰ４２重量％とし、内添の軽質炭酸カルシウム（平均粒子径：２．２μｍ）を１１重量％含有させて、ポリアクリルアミド系紙力剤０．０３重量％、及び定着剤として硫酸バンド０．８重量％を添加して、紙料を調成した。 <Manufacture of base paper>
The pulp composition constituting the base paper was KP 40% by weight, GP 10% by weight, TMP 10% by weight and DIP 42% by weight, containing 11% by weight of light calcium carbonate (average particle size: 2.2 μm) internally added, and polyacrylamide A paper stock was prepared by adding 0.03% by weight of a paper strength agent and 0.8% by weight of a sulfuric acid band as a fixing agent.
　この紙料をツインワイヤー抄紙機にて１２００ｍ／分で抄造し、坪量４１ｇ／ｍ2の原紙を得た。 This stock was made at 1200 m / min with a twin wire paper machine to obtain a base paper having a basis weight of 41 g / m 2 .
　＜塗工液の調製＞
　微粒カオリン（レーザー法による平均粒子径０．２２μｍ、ハイドラグロス・Imerys社製）３０重量部、エンジニアードカオリン（レーザー法による平均粒子径３．５６μｍ、、Contour1500・Imerys社製）３０重量部、平均粒子径８．１μｍのモノカーボネート３０重量部、及びルチル型の二酸化チタン１０重量部からなる顔料を、ポリアクリル酸ソーダ分散剤０．２重量部を配合した水に加えてセリエミキサーで分散して、固形分濃度が５５重量％の顔料スラリーを調整した。この顔料スラリーに、スチレン・ブタジェン共重合体ラテックス（Ｌｘ：NP100B・JSR社製など）を９重量部、ヒドロキシェチルェーテル化デンプン（Ｍ２１０：隅田化学製）を７．５重量部、印刷適性向上剤（ＳＰＩ１０６Ｎ：星光ＰＭＣ社製）を０．５重量部、滑材（ＳＮ２３１ＳＰ：サンノプコ社製）を０．５重量部、黒色染料（ＳＡブラックＡ０３５：御国色素製）を１５０ｐｐｍ加え、さらに水を加えて固形分濃度が５５重量％の顔料塗工液を得た。 <Preparation of coating solution>
30 parts by weight of fine kaolin (average particle size 0.22 μm by laser method, Hydragros / Imerys), 30 parts by weight of engineered kaolin (average particle size 3.56 μm by laser method, manufactured by Contour1500 / Imerys), average A pigment composed of 30 parts by weight of monocarbonate having a particle size of 8.1 μm and 10 parts by weight of rutile type titanium dioxide was added to water mixed with 0.2 parts by weight of a polyacrylic acid soda dispersant, and dispersed with a serie mixer. A pigment slurry having a solid content concentration of 55% by weight was prepared. To this pigment slurry, 9 parts by weight of styrene / butadiene copolymer latex (Lx: NP100B, manufactured by JSR, etc.) and 7.5 parts by weight of hydroxyethyl etherified starch (M210: Sumida Chemical) are printed. Add 0.5 parts by weight of suitability improver (SPI106N: manufactured by Seiko PMC), 0.5 parts by weight of lubricant (SN231SP: manufactured by San Nopco), 150 ppm of black dye (SA Black A035: manufactured by Gokoku Dye), Water was added to obtain a pigment coating solution having a solid concentration of 55% by weight.
　＜塗工紙の調製＞
　前記した原紙の両面に、片面あたりの塗工量が３．５ｇ／ｍ2になるように、それぞれ１２００ｍ／分の塗工速度でショートデュエル型のブレードコータを用いて上記の塗工液を塗工し、スキャッフドライヤーを通過させた後、シリンダードライヤーにて紙中水分が５．５％になるように乾燥した。 <Preparation of coated paper>
Apply the above coating solution on both sides of the base paper using a short duel type blade coater at a coating speed of 1200 m / min so that the coating amount per side becomes 3.5 g / m 2. After passing through a scuff dryer, the paper was dried with a cylinder dryer so that the moisture in the paper was 5.5%.
　＜カレンダー処理＞
　次いで、オンラインのソフトニップカレンダを用いて表面処理を行い、印刷用塗工紙を製造した。ソフトカレンダーは、金属ロール温度が１５０℃、弾性ロールのショアーＤ硬度が８５、通紙速度が１２００ｍ／分、線圧が２００ｋＮ／ｍ、カレンダーニップ数が４ニップの条件で表面処理を行った。 <Calendar processing>
Subsequently, surface treatment was performed using an online soft nip calender to produce a coated paper for printing. The soft calender was subjected to surface treatment under the conditions of a metal roll temperature of 150 ° C., an elastic roll with a Shore D hardness of 85, a paper feed speed of 1200 m / min, a linear pressure of 200 kN / m, and a calender nip number of 4 nips.
　比較例１
　平均粒子径が８．１μｍのモノカーボネートに代えて、平均粒子径が１．０μｍのモノカーボネートを３０重量部用いた以外は、実施例１と同様にして印刷用塗工紙を得た。 Comparative Example 1
A coated paper for printing was obtained in the same manner as in Example 1 except that 30 parts by weight of monocarbonate having an average particle diameter of 1.0 μm was used instead of monocarbonate having an average particle diameter of 8.1 μm.
　比較例２
　平均粒子径が８．１μｍのモノカーボネートを配合せず、微粒カオリンを３０重量部増配とした以外は、実施例１と同様にして印刷用塗工紙を得た。 Comparative Example 2
A coated coated paper for printing was obtained in the same manner as in Example 1 except that monocarbonate having an average particle size of 8.1 μm was not blended and fine kaolin was increased by 30 parts by weight.
　比較例３
　平均粒子径が８．１μｍのモノカーボネートを配合せず、２級カオリン（レーザー法による平均粒子径１．５０μｍ、KCS・Imerys社製）を３０重量部配合した以外は、実施例１と同様にして印刷用塗工紙を得た。 Comparative Example 3
Example 1 is the same as Example 1 except that monocarbonate having an average particle size of 8.1 μm is not blended and secondary kaolin (average particle size by laser method: 1.50 μm, manufactured by KCS / Imerys) is blended by 30 parts by weight. Thus, a coated paper for printing was obtained.
　比較例４
　平均粒子径が８．１μｍのモノカーボネートを配合せず、エンジニアードカオリン（Contour1500・Imerys社製）を３０重量部増配した以外は、実施例１と同様にして印刷用塗工紙を得た。 Comparative Example 4
A coated paper for printing was obtained in the same manner as in Example 1, except that monocarbonate having an average particle size of 8.1 μm was not blended and engineered kaolin (Contour 1500, manufactured by Imerys) was added in an amount of 30 parts by weight.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に評価結果を示す。表１から明らかなように、実施例１の本発明の塗工紙は、不透明度、剛度（曲げこわさ）、裏抜け、ドライピック強度、白色度、印刷光沢度など、すべの面で優れており、オフセット印刷などの印刷用塗工紙として良好であることが確認された。 Table 1 shows the evaluation results. As is apparent from Table 1, the coated paper of the present invention of Example 1 is excellent in all aspects such as opacity, stiffness (bending stiffness), back-through, dry pick strength, whiteness, and printing gloss. As a result, it was confirmed to be good as a coated paper for printing such as offset printing.
　粒径の異なるカーボネートを用いた実施例１（平均粒径：８．１μｍ）と比較例１（平均粒径：１．０μｍ）を比較すると、実施例１は、比較例１と比較して光沢が若干劣るものの、曲げこわさやドライピック強度が有意に高いことが確認され、本発明の印刷用塗工紙は印刷時の耳折れやパイリングが生じにくい。 When Example 1 (average particle size: 8.1 μm) using carbonates having different particle sizes was compared with Comparative Example 1 (average particle size: 1.0 μm), Example 1 was glossy as compared with Comparative Example 1. Although it is slightly inferior, it is confirmed that the bending stiffness and the dry pick strength are significantly high, and the coated paper for printing of the present invention is less likely to bend or pile during printing.
　また、実施例１の印刷用塗工紙は、カーボネートと同じ板状顔料であるカオリンを用いた比較例２・３と比較して、特に曲げこわさ（剛度）、裏抜け、ドライピック強度（表面強度）に優れていた。このように、本発明の比較的粒径の大きいカーボネートを顔料として用いることによって、印刷用塗工紙の剛度や裏抜け、顔料塗工層の表面強度を改善できることが確認された。 In addition, the coated coated paper of Example 1 is particularly resistant to bending stiffness (stiffness), back-through, and dry pick strength (surface) as compared to Comparative Examples 2 and 3 using kaolin, which is the same plate-like pigment as carbonate. Strength). As described above, it was confirmed that by using the carbonate having a relatively large particle diameter according to the present invention as a pigment, the rigidity and back-through of the coated paper for printing and the surface strength of the pigment coated layer can be improved.
　［実験例２：グラビア印刷用塗工紙］
　評価方法
　本発明における各種評価方法の詳細は以下のとおりである。
（１）坪量　坪量はJIS P8124に準じて測定した。
（２）クラークこわさ
　JIS P8143に準じてマシン方向（ＭＤ）のクラークこわさを測定した。
（３）ミッシングドット
　大蔵省式グラビア印刷機（熊谷理器工業製）を用いて、印刷速度４００ｍ／分、印圧１０ｋｇｆ／ｃｍで印刷し、得られた印刷物についてミッシングドットの発生状況を目視により評価した。評価基準は以下の通りである。◎：非常に良好、○：良好、△：やや劣る、×：劣る。 [Experimental Example 2: Coated paper for gravure]
Evaluation Method Details of various evaluation methods in the present invention are as follows.
(1) Basis weight Basis weight was measured according to JIS P8124.
(2) Clark stiffness The stiffness of the machine direction (MD) was measured according to JIS P8143.
(3) Missing dots Using a Ministry of Finance gravure printing machine (manufactured by Kumagai Riki Kogyo), printing was performed at a printing speed of 400 m / min and a printing pressure of 10 kgf / cm, and the occurrence of missing dots was evaluated visually. did. The evaluation criteria are as follows. A: Very good, B: Good, B: Slightly inferior, X: Inferior
　実施例１
　＜モノカーボネートの合成＞
　実験例１と同様に、モノカーボネートとして、平均粒子径が８．１μｍと１．０μｍのモノカーボネート（古手川産業製）を使用した。平均粒子径８．１μｍのモノカーボネートは、特開２００８－３７６６４号公報に記載されたように水酸化アルミニウムを摩砕処理し、メカノケミカル的に消石灰および炭酸カルシウムと水の存在下で反応させることによって合成したが、水酸化アルミニウムの摩砕時間を短くし、反応終了までの時間を長くした。平均粒子径１．０μｍのモノカーボネートは特開２００８－３７６６４号公報記載の方法で合成された。 Example 1
<Synthesis of monocarbonate>
Similarly to Experimental Example 1, monocarbonates (manufactured by Kotegawa Sangyo Co., Ltd.) having an average particle size of 8.1 μm and 1.0 μm were used as monocarbonates. Monocarbonate having an average particle size of 8.1 μm is obtained by grinding aluminum hydroxide as described in Japanese Patent Application Laid-Open No. 2008-37664 and reacting mechanochemically with slaked lime and calcium carbonate in the presence of water. However, the grinding time of aluminum hydroxide was shortened and the time until completion of the reaction was lengthened. Monocarbonate having an average particle size of 1.0 μm was synthesized by the method described in JP-A-2008-37664.
　＜塗工原紙＞　塗工原紙として、坪量３５ｇ／ｍ2の中質紙を用いた。塗工原紙のパルプ配合は、ＬＢＫＰ３６重量％、ＮＢＫＰ３２重量％、ＮＴＭＰ２２重量％、ＤＩＰ１０重量％であり、填料として軽質炭酸カルシウム（平均粒子径：２．２μｍ）を用い、原紙灰分が原紙重量あたり１０％となるように調整した。 <Coating Base Paper> As the coating base paper, a medium quality paper having a basis weight of 35 g / m 2 was used. The pulp composition of the coated base paper is LBKP 36% by weight, NBKP 32% by weight, NTMP 22% by weight, DIP 10% by weight, light calcium carbonate (average particle size: 2.2 μm) is used as a filler, and the base paper ash content is 10 per base paper weight. % Was adjusted.
　＜塗工液の調製＞　カルシウムアルミネートモノカーボネートＰ（平均粒子径８．１μｍ、古手川産業製）３０重量部、エンジニアードカオリン（ＣａｐｉｍＤＧ、平均粒子径１．１９μｍ、ＩＭＥＲＹＳ製）７０重量部からなる顔料をセリエミキサーで水中に分散し、無機顔料スラリーを調製した。調製した顔料スラリーに、スチレン・ブタジエン共重合体ラテックス（ガラス転移温度－４０℃）１０部を加え、アクリル系合成保水剤０．４部と水を加えて、固形分濃度６５％の塗工液を得た。 <Preparation of coating solution> Consisting of 30 parts by weight of calcium aluminate monocarbonate P (average particle size 8.1 μm, manufactured by Kotegawa Sangyo) and 70 parts by weight of engineered kaolin (CapimDG, average particle size 1.19 μm, manufactured by IMERYS) The pigment was dispersed in water with a serie mixer to prepare an inorganic pigment slurry. To the prepared pigment slurry, 10 parts of styrene / butadiene copolymer latex (glass transition temperature −40 ° C.) is added, 0.4 part of an acrylic synthetic water retention agent and water are added, and the coating liquid has a solid content concentration of 65%. Got.
　＜塗工紙の調製＞　前記した原紙の両面に、片面あたりの塗工量が７ｇ／ｍ2になるように、５００ｍ／分の塗工速度でブレードコータを用いて上記塗工液を両面に塗工した。塗工後、スキャッフドライヤーを通過させ、シリンダードライヤーにて紙中水分が５．５％になるように乾燥した。 <Preparation of coated paper> On both sides of the above-mentioned base paper, apply the above coating solution on both sides using a blade coater at a coating speed of 500 m / min so that the coating amount per side is 7 g / m 2. Coated. After coating, it was passed through a scuff dryer and dried with a cylinder dryer so that the moisture in the paper was 5.5%.
　＜表面処理＞　さらにソフトニップカレンダー処理を行い、グラビア印刷用塗工紙を得た。カレンダー条件は、金属ロール温度１６０℃、弾性ロールのショアーＤ硬度８５、通紙速度６００ｍ／分、線圧４０ｋｇ／ｃｍとし、カレンダーニップ数を４ニップとした。 <Surface Treatment> Further, soft nip calendering was performed to obtain a coated paper for gravure printing. The calendar conditions were a metal roll temperature of 160 ° C., an elastic roll Shore D hardness of 85, a paper feed speed of 600 m / min, a linear pressure of 40 kg / cm, and a calendar nip number of 4 nips.
　実施例２
　実施例１に関して、カルシウムアルミネートモノカーボネートＰを７０重量部、エンジニアードカオリン３０重量部とし、固形分濃度を５０％とした以外は、実施例１と同様の方法にて塗工紙を得た。 Example 2
Regarding Example 1, coated paper was obtained in the same manner as in Example 1 except that calcium aluminate monocarbonate P was 70 parts by weight, engineered kaolin was 30 parts by weight, and the solid content concentration was 50%. .
　比較例１
　カルシウムアルミネートモノカーボネートを配合せず、エンジニアードカオリンの配合量を１００重量部とした以外は、実施例１と同様にしてグラビア印刷用塗工紙を得た。 Comparative Example 1
A gravure-coated paper was obtained in the same manner as in Example 1 except that calcium aluminate monocarbonate was not blended and the amount of engineered kaolin was 100 parts by weight.
　比較例２
　平均粒子径が８．１μｍのカルシウムアルミネートモノカーボネート（Ｐ、古手川産業製）に代えて平均粒子径が１．０μｍのカルシウムアルミネートモノカーボネート（Ｖ３、古手川産業製）を使用した以外は、実施例１と同様にしてグラビア印刷用塗工紙を得た。 Comparative Example 2
Except that calcium aluminate monocarbonate (V3, manufactured by Kotegawa Sangyo) with an average particle size of 1.0 μm was used instead of calcium aluminate monocarbonate (P, manufactured by Kotegawa Sangyo) with an average particle size of 8.1 μm. In the same manner as in Example 1, a coated paper for gravure printing was obtained.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に、実施例および比較例で得られた塗工紙の試験結果を示す。表１から明らかなように、本発明の塗工紙は、実施例１、実施例２ともに、軽量にも関わらず、剛度が高く維持され、クラーク剛度が高く、ミッシングドットが少なくグラビア印刷適性が優れていた。一方、比較例１の塗工紙は、剛度が低く、グラビア印刷適性が劣っていた。また、比較例２の塗工紙は、剛度が不足するために印刷作業性が劣っていた。 Table 2 shows the test results of the coated paper obtained in Examples and Comparative Examples. As is clear from Table 1, the coated paper of the present invention has both high rigidity, high Clark rigidity, low missing dots, and good gravure printing suitability in both Examples 1 and 2, despite being lightweight. It was excellent. On the other hand, the coated paper of Comparative Example 1 had low rigidity and poor gravure printing suitability. Further, the coated paper of Comparative Example 2 was inferior in printing workability due to insufficient rigidity.

Claims (4)

  1. 　原紙と顔料塗工層を有する印刷用塗工紙であって、
    　顔料塗工層が、平均粒子径が２～１５μｍであるカルシウムアルミネートモノカーボネートを含んでなる、上記印刷用塗工紙。     A printing paper having a base paper and a pigment coating layer,
    The above-mentioned coated paper for printing, wherein the pigment coating layer comprises calcium aluminate monocarbonate having an average particle diameter of 2 to 15 μm.
  2. 　前記カルシウムアルミネートモノカーボネートの平均粒子径が２～１０μｍである、請求項１に記載の塗工紙。 The coated paper according to claim 1, wherein the calcium aluminate monocarbonate has an average particle diameter of 2 to 10 µm.
  3. 　坪量が３０～６０ｇ／ｍ2である、請求項１または２に記載の塗工紙。 The coated paper according to claim 1 or 2, wherein the basis weight is 30 to 60 g / m 2 .
  4. 　グラビア印刷用である、請求項１または２に記載の塗工紙。 The coated paper according to claim 1 or 2, which is for gravure printing.
PCT/JP2010/055077 2009-03-31 2010-03-24 Coated paper for printing WO2010113721A1 (en)

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JP2009-086719 2009-03-31
JP2009086180A JP4668327B2 (en) 2009-03-31 2009-03-31 Coated paper for printing
JP2009-086180 2009-03-31
JP2009086719A JP4668328B2 (en) 2009-03-31 2009-03-31 Coated paper for gravure printing

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007100227A (en) * 2005-09-30 2007-04-19 Daio Paper Corp Newsprint paper
JP2008037664A (en) * 2006-08-01 2008-02-21 Kotegawa Sangyo Kk Method for producing calcium aluminate monocarbonate
JP2008196056A (en) * 2007-02-08 2008-08-28 Kotegawa Sangyo Kk Coated paper using calcium aluminate compound

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007100227A (en) * 2005-09-30 2007-04-19 Daio Paper Corp Newsprint paper
JP2008037664A (en) * 2006-08-01 2008-02-21 Kotegawa Sangyo Kk Method for producing calcium aluminate monocarbonate
JP2008196056A (en) * 2007-02-08 2008-08-28 Kotegawa Sangyo Kk Coated paper using calcium aluminate compound

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