JP2010007206A - Method for producing matte coated paper for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a matte coated paper for printing, especially a matte coated paper causing little rubbing stain and damage. <P>SOLUTION: In the method for producing a matte coated printing paper having one or more coating layers composed mainly of a pigment and an adhesive on at least one surface of a base paper, eucalyptus and/or acacia are used as 50% or more of bleached pulp used in the base paper, the bleached pulp is pulp produced by pulping the material by a kraft cooking method to dividedly add a cooking liquor and bleaching the cooked pulp by a multistage bleaching process including an ozone bleaching step, and the base paper made from a paper material containing the bleached pulp is once wound up, delivered again, coated with a coating liquid and dried to form a coating layer optionally after smoothing the coating layer, and wound up in the form of a roll by a center-drive winder. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a matte coated paper for printing.

  A matte coated paper is a coated paper that intentionally lowers the surface gloss of a white paper and gives an elegant and deep tone as a printed matter to give a high-class feeling. Such matte coated paper is widely used in high-quality art printing, high-quality posters, catalogs, calendars and the like. In general, matte coated paper is manufactured in two ways. One of them is a pigment having a large average particle size and a coarse particle (usually an average particle size of about 0.1 μm) compared to a pigment (usually an average particle size of 0.1 to 2 μm) used for ordinary glossy coated paper. A coating solution containing 4 to 10 μm) is coated on a base paper and dried to produce a product as it is, or a mild calendar process is performed to produce a product. The other is a method that uses a roughened calender roll to transfer the rough surface of the micron unit of the roll onto the surface of the pigment coating layer that has been smoothly applied to the surface of the coating layer and finish it with a matte finish. is there.

  The matte coated paper produced in this way has practical problems due to its uneven surface. In particular, as a big problem, a rust stain or shine gloss is generated by rubbing the blank paper portion, the product value is lowered, and in a severe case, a huge loss is incurred as a user complaint.

  The problem of scumming stains peculiar to the matte coated paper is that the coating layer is rough, or is roughened by passing it through a roughened calender roll. The surface has large irregularities as compared to glossy coated paper. Due to this, it is presumed that the unevenness of the blank paper portion acts like a sandpaper, causing a smudge or a partial gloss, and is recognized as a defect.

  For this reason, as a coated paper, the following method has been proposed as a means for avoiding problems such as blurring and scratches. A method of blending at least one pigment selected from kaolin, delaminated kaolin, and talc having an average particle diameter of 1.5 μm or more as a pigment, in an amount of 40% by mass or more based on the total pigment (see Patent Document 1), calendar A matte coated paper for printing, which contains 90 parts by mass or more of kaolin as a tragic pigment, and the average particle size of 5 to 15 parts by mass of kaolin out of the kaolin is 1.5 μm or more. A coating solution containing 60 to 90% by mass of kaolin and a styrene-butadiene copolymer latex having a specific particle size as an adhesive component with respect to 100% by mass of the pigment component. A method of applying a calendar process after coating and drying (see Patent Document 3) has been proposed. Further, although there is disclosure of a device for winding paper or coated so-called web in a roll shape (see Patent Document 4), the suitability of rust stains, shine gloss, scratches, etc. on matte coated paper for printing is disclosed. Therefore, further improvement is desired.

JP-A-9-31892 Japanese Patent Laid-Open No. 9-273098 Japanese Patent Laid-Open No. 10-140498 JP 2003-146499 A

  The present invention relates to a matte coated paper for printing, and in particular, to provide a method for producing a matte coated paper for printing with less occurrence of smearing and scratches.

  The present invention relates to a method for producing a matte coated paper for printing in which one or more coating layers mainly composed of a pigment and an adhesive are provided on at least one side of a base paper, and 50% of bleached pulp used for the base paper. The above is a raw material made from eucalyptus or acacia wood, and the bleached pulp is pulped by the kraft cooking method in which the cooking liquor is dividedly added, and further produced by a multistage bleaching process including an ozone bleaching stage. After the base paper made with the stock containing the bleached pulp is wound up, the coating layer is formed in the process of drawing out again and applying and drying the coating liquid, or the coating layer After smoothing is performed, the film is wound into a roll shape in the center drive format.

  Among the coating layers formed on the base paper, the pigment contained in the outermost pigment coating layer is kaolin having an average particle diameter in the range of 0.2 to 1.2 μm, and the outermost pigment coating layer. More than 60% by mass of the total pigment, and more than 5% by mass of the kaolin is preferably delaminated kaolin.

The delaminated kaolin preferably satisfies all the following conditions (a) to (c).
(A) The ratio of particles smaller than 5 μm is 90 to 100% by mass.
(B) The proportion of particles smaller than 2 μm is 70 to 90% by mass.
(C) The proportion of particles smaller than 1 μm is 30 to 70% by mass.

  In the winder process of dividing the roll wound in the center drive format, the winder is preferably a single drum winder format.

  By producing a matte coated paper for printing using a base paper using a specific pulp in the present invention and using a specific winding device, a desired effect with less occurrence of smudge and scratches can be obtained. It is done.

The present invention is described in detail below.
The raw material of the pulp used in the present invention may be hardwood, softwood, or non-wood, but 50% or more of the pulp used for paper must be made from eucalyptus or acacia. Don't be. This is because pulp made of eucalyptus wood and acacia wood has a small fiber width and is indispensable for exhibiting good white paper quality and printing quality of the present invention. Eucalyptus materials include E. camaldulensis, E. citriodora, E. deglupta, E. globulus, E. grandis, E. maculata, E. punctata, E. saligna, E. terelicornis, E. urophylla, E. camaldulensis, etc. These hybrids are mentioned, and as acacia wood, A.aulacocarpa, A.auriculiformis, A.catechu, A.crassicarpa, A.decurrens, A.holosericea, A.leptocarpa, A.maidenii, A.mangium A. mearnsii, A. melanoxylon, A. neriifolia, A. silvestris, etc. and their hybrids.

  As the cooking method for obtaining the pulp used in the present invention, known cooking methods such as kraft cooking, polysulfide cooking, soda cooking, alkali sulfite cooking, etc. can be used. It needs to be cooked. By adding the cooking liquor in a divided manner, the alkali concentration in the entire cooking can be kept low, elution of hemicellulose in the material is suppressed, and as a result, a pulp having a high hemicellulose content is obtained. The use of a high amount of pulp is one of the matters indispensable for the expression of the paper physical properties of the present invention. The cooking method is not particularly limited as long as it is a split-added cooking method, but the cooking methods such as the Lo-solids method, the Compact cooking method, the Kobudomari cooking method, etc. use a small amount of energy for cooking. It is preferably used from the standpoint of incidental effects such as good bleachability of the pulp to be produced.

  For example, when the kraft cooking method is used, the degree of sulfidation of the cooking liquor is 5 to 75%, preferably 15 to 45%, and the effective alkali addition rate is 5 to 30% by weight, preferably 10 to 25% by weight, based on the mass of absolutely dry wood. The cooking temperature is 130 to 170 ° C., and the cooking method may be either a continuous cooking method or a batch cooking method.

  In cooking, a known cyclic keto compound as a cooking aid in the cooking solution to be used, for example, benzoquinone, naphthoquinone, anthraquinone, anthrone, phenanthroquinone and quinone-based compounds such as alkyl, amino, or the like, or the quinone-based compound One kind selected from hydroquinone compounds such as anthrahydroquinone which is a reduced form of 9,10-diketohydroanthracene compound which is a stable compound obtained as an intermediate of anthraquinone synthesis method by Diels Alder method Or 2 or more types may be added and the addition rate is 0.001-1.0 mass% per the absolute dry mass of a material.

  In this invention, the unbleached pulp obtained by the well-known cooking method is delignified by the well-known alkaline oxygen bleaching method through a washing | cleaning, a rough selection, and a selection process. This is because delignification by the alkaline oxygen bleaching method can reduce the amount of bleaching chemicals used in the subsequent multistage bleaching step and minimize damage to the pulp quality. As the alkaline oxygen bleaching method used in the present invention, a known medium concentration method or a high concentration method can be applied as it is, but a medium concentration method which is currently used at a pulp concentration of 8 to 15% is widely used. preferable.

  In the alkali oxygen bleaching method by the medium concentration method, caustic soda or oxidized kraft white liquor can be used as the alkali, and oxygen gas is oxygen from a cryogenic separation method, from PSA (Pressure Swing Adsorption). Oxygen, oxygen from VSA (Vacuum Swing Adsorption), etc. can be used. The oxygen gas and alkali are added to a medium-concentration pulp slurry in a medium-concentration mixer. After sufficient mixing, the oxygen gas and alkali are sent to a reaction tower capable of holding a mixture of pulp, oxygen, and alkali for a certain period of time under pressure. Ligned.

  The oxygen gas addition rate is 0.5 to 3% by mass per mass of dry pulp, the alkali addition rate is 0.5 to 4% by mass, the reaction temperature is 80 to 120 ° C., the reaction time is 15 to 100 minutes, and the pulp concentration Is 8 to 15%, and other known conditions can be applied. In the present invention, in the alkaline oxygen bleaching step, it is a preferred embodiment that the alkali oxygen bleaching is continuously performed a plurality of times and delignification proceeds as much as possible.

  The pulp that has been subjected to alkaline oxygen bleaching is then sent to a washing step. After washing, the pulp is sent to a multistage bleaching process.

  In the multistage bleaching step for obtaining the bleached pulp used in the present invention, the ozone bleaching stage (Z) is always used. This is because by using the ozone bleaching stage, hexeneuronic acid contained in a large amount in the pulp from eucalyptus wood and acacia wood can be decomposed, and the color return of the pulp due to hexeneuronic acid can be suppressed. The treatment conditions of the ozone bleaching stage of the present invention are not particularly limited, but when ozone is reacted excessively, the pulp strength is impaired. It is 0.1% to 1.0%, and more preferably 0.3% to 0.7%. The treatment temperature is 10 ° C to 100 ° C, preferably 20 ° C to 70 ° C, the treatment time is 1 second to 60 minutes, preferably 10 seconds to 5 minutes, and the treatment pH is 1.5 to 7, preferably 2 to 4. . The pulp concentration in the ozone bleaching stage may be medium or high, and is not limited. If necessary, chlorine dioxide and other bleaching chemicals can be used in combination.

  The bleaching stage that can be used in the multistage bleaching process of the present invention is not particularly limited except that an ozone bleaching stage is used, and a known bleaching stage can be used. Known bleaching stages include chlorine dioxide bleaching stage (D), alkali extraction stage (E), oxygen bleaching stage (O), hydrogen peroxide bleaching stage (P), peracid bleaching stage (PA), acid washing stage (a ), Acid treatment stage (A) and the like. Examples of the multi-stage bleaching process include ZEPD, ZEDP, ZEPP, AZPEPD, and AZED. -P, A-Z-E-P-AP, a-Z-E-P-D, a-Z-E-D-P, a-Z-E-P-AP, Z / D-E-P -D, Z / D-E-D-P, Z / D-E-P-AP, AZ / D-E-P-D, AZ / D-E-D-PA-Z / D -E-P-AP, a-Z / D-E-P-D, a-Z / D-E-D-P, a-Z / D-E-P-AP, Z-EO-P-D , Z-EO-DP, Z-EO-P-AP, AZ-EO-PD, AZ-EO-DP, AZ-EO-P-AP, a-Z -EO-P-D, a-Z-EO-DP, a-Z-EO-P-AP, Z / D-EO-PD, Z / D-EO-DP, Z / D -EO-P- P, AZ / D-EO-PD, AZ / D-EO-DP, AZ / D-EO-P-AP, aZ / D-EO-PD, a-Z / D-EO-DP, aZ / D-EO-P-AP, and the like, and a washing stage may be provided in the hyphone unit. Further, a bleaching stage can be further added, or another bleaching stage can be incorporated in the bleaching stage and used together, and is not particularly limited. The pulp after multistage bleaching is sent to a beating process or a papermaking process.

  Since the specific pulp of the present invention has fine fibers, the number of fibers per unit tsubo increases, and the smoothness of the base paper improves, so that the surface of the resulting matte coated paper for printing becomes smooth, resulting in blank paper quality and In addition to improving print quality, it can also effectively prevent the occurrence of scratches.

  In addition, to the above-mentioned pulp, as long as the effects of the present invention are not impaired, mechanical pulp such as crushed wood pulp, pressurized ground wood pulp, refiner ground wood pulp, thermomechanical pulp, deinked waste paper pulp, waste paper, etc. are used as appropriate can do.

  The pulp constituting the base paper is subjected to a beating process, and then sent to a paper machine as a paper stock which is a slurry-like pulp aqueous dispersion. For this paper material, fillers, internally added sizing agents, anionic, nonionic, cationic or amphoteric retention improvers, drainage improvers, paper strength enhancers, etc. It can be added as necessary.

  Examples of the filler used for forming the base paper in the present invention include heavy calcium carbonate, light calcium carbonate, calcium sulfite, gypsum, talc, clay, calcined kaolin, white carbon, amorphous silica, delaminated kaolin, Examples include inorganic pigments such as diatomaceous earth, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, and zinc hydroxide, and organic pigments such as urea / formalin resin fine particles and fine hollow particles. Fillers contained in paper can be reused. Two or more fillers can be used in combination. The blending amount of the filler is generally added so that the paper (base paper) ash content is in the range of 3 to 20% by mass.

  Specific examples of the internally added sizing agent used in the present invention include, for example, sizing agents such as alkyl ketene dimer, alkenyl succinic anhydride, styrene-acrylic, higher fatty acid, petroleum resin, and rosin. Is mentioned. Specific examples of yield improvers, filter pigment improvers, and paper strength enhancers include, for example, polyvalent metal compounds such as aluminum (specifically, sulfate bands, aluminum chloride, sodium aluminate, basic aluminum compounds). Etc.), various starches, polyacrylamide, urea resin, polyamide / polyamine resin, polyethyleneimine, polyamiin, polyvinyl alcohol, polyethylene oxide and the like. Moreover, it is also possible to use a bulking agent and a softening agent having a function of inhibiting the binding between pulp fibers as long as the effects of the present invention are not hindered. Specific examples of bulking agents and softeners include, for example, ester compounds of polyhydric alcohols and fatty acids, polyoxyalkylene compounds of polyhydric alcohols and fatty acid ester compounds, fatty acid polyamidoamines, polyhydric alcohol surfactants, An ionic surfactant etc. can be illustrated. The amount of the bulking agent and the softening agent is generally about 0.05 to 2.0% by mass relative to the pulp in terms of dry weight.

  There are no particular limitations on the papermaking (former) format, and twin wire formers, on-top formers, gap formers, and the like can be used. When making a base paper at a high speed exceeding 1200 m / min, it is preferable to make a paper in a gap former format that is excellent in operability and quality of the obtained base paper.

Regarding the papermaking conditions of the base paper, any system such as acidic papermaking, neutral papermaking, and weak alkali papermaking may be used. The base paper can be subjected to a normal size press treatment using an adhesive such as a starch derivative, polyvinyl alcohol, or polyacrylamide, and can also be subjected to a smoothing finishing treatment using a machine calendar, a soft calendar, or the like. As the size press apparatus, a two-roll type, a gate roll type, a film transfer type, and the like can be used. In the case of operation at a high speed of 1000 m / min or more, a film transfer type that is excellent in operability is preferable. The basis weight of the base paper made under these paper making conditions is preferably in the range of 30 to 150 g / m ² .

  In the present invention, the paper that has been made and dried in the paper making process is subjected to a size press process as necessary, and after winding the base paper, the wound base paper is fed out again to apply the coating liquid. Then, after the coating layer is dried and the coating layer is formed, or after the coating layer is formed and smoothed, the film is wound into a roll in the center drive format. This center drive roll type is less likely to cause winding scratches and uneven gloss compared to other types, and is less likely to cause air entrainment in the winding, thereby preventing winding defects. When winding the base paper, it may be wound in the center drive format.

Hereinafter, the center drive roll method will be described.
In the reel, the running paper sheet is wound around a reel spool, and wound while being pressed against the reel drum, thereby forming a winding. As a drive form in the reel, a center drive roll form is used in which a reel spool is connected to a drive system via a chuck and is responsible for rotational drive of winding.

  The material of the reel drum to which the paper sheet take-up during driving is pressed can be metallic, resin, ceramic, etc., but since it is used continuously for a long time at high speed, the reel drum main A metal object is used as the material.

  As a reel drum that rotates while being in contact with the winding surface being wound, applies a rotational driving force to the web roll being wound, or applies running tension to the web being wound on the web roll, Narrow grooves of narrow and deep grooves are spirally formed on the drum surface, and wide grooves of wide and shallow grooves are formed spirally on the narrow groove, so that air can be caught in the winding. Since it can prevent, it is a preferable form. Moreover, it is preferable that the cross-sectional shape of the said wide-width groove | channel in the roll axial direction is circular arc shape, and it continues smoothly with the flat part between adjacent wide grooves. It is preferable that both the narrow groove and the wide groove are formed as two-way spiral grooves that respectively proceed from the axial center portion of the roll toward both ends, and the narrow groove and the wide groove are These are preferably formed as one-way spiral grooves from one end to the other end of the roll, and a preferable embodiment is that the surface of the reel drum is subjected to tungsten carbide spraying.

  Further, a reel drum is used in which a rubber plate is wound around the surface of the reel drum, a belt-like protrusion is provided on the rubber surface, and the belt-like protrusion is wound around the reel drum surface in a ring shape or a spiral shape. Thus, in addition to the effect of preventing the air from being caught in the winding, it can also contribute to the prevention of winding vibration, and can be exemplified as a preferable form for the cosmetic. Moreover, in order to prevent air entrainment in winding, it is also a preferable form to perform hole processing by gun drill processing or the like.

  If the diameter of the reel drum that contacts and presses the winding is small, excessive linear pressure is likely to be applied to the winding with a large diameter, resulting in quality defects such as scrapes on the paper sheet surface. Problems occur. For this reason, the diameter of the reel drum is preferably 1100 to 1800 mm.

  The material of the reel spool that is pressed against the paper sheet take-up while traveling can be metallic, resin, ceramic, etc., but it has the strength to support the weight of the take-up. Since it is required and used repeatedly, and the conveyance is mainly handled in the automatic conveyance process, a high impact resistance is required. For this reason, a metal object is used as the main material of the reel spool.

  As the reel spool surface material, the surface of the reel spool is used to minimize the amount of defects at the winding center of the paper product to be obtained, or to prevent scratches when the reel spools come into contact with each other. It is preferable that a material such as rubber or polyurethane is wound around. Further, as the rubber or resin surface, a narrow groove of narrow and deep grooves is formed in a spiral shape, and a wide groove of a wide and shallow groove is formed in a spiral shape on the narrow groove so that winding is performed. This is a preferred mode because it can contribute to prevention of air entrainment and vibration of winding. Further, the wide groove preferably has a cross-sectional shape in the roll axis direction at the groove bottom in an arc shape and is smoothly continuous with a flat portion between adjacent wide grooves, and the narrow groove and the wide groove It is preferable that the grooves are formed as two-way spiral grooves that respectively advance from the axial center of the roll toward both ends, and the narrow groove and the wide groove are both from one end of the roll. It is preferably formed as a spiral groove in one direction toward the other end. Furthermore, in order to obtain the same effect, a preferable example is one in which a belt-like protrusion is provided on the rubber or resin surface, and the belt-like protrusion is formed in a ring shape or a spiral shape on the reel drum surface. be able to.

  In order to obtain winding corresponding to a wide and high papermaking speed, sufficient strength as a reel spool is required. For this reason, the reel spool diameter should be large, but if it is too large, the reel spool itself will increase in mass, increasing the weight of the winding and making it difficult to handle the winding. In actual operation, a reel spool having a diameter of 900 to 1500 mm is preferably used.

  In the center drive system, it is necessary to support the self-weight of the winding by the spool at the center of the winding, but due to the large diameter and widening of the winding, there is a tendency for the mass that the spool cannot support to increase. For this reason, when the spool alone is supported, the load on the spool and the member connected to the spool may be too large. In order to avoid this, a belt roll formed in a loop with a belt, preferably a belt with no joint, is arranged in contact with or support the winding between the two rolls at or near the lower part of the winding. Is also possible.

  In order to adjust the winding hardness of the winding, the nip pressure is adjusted by adjusting the nip pressure by adjusting the pressing pressure between the winding and the reel drum, or by adjusting the pressing pressure by the arm such as the belt roll described above. The method of adjusting is mentioned. In addition, in order to adjust the nip pressure with respect to the reel drum, together with a driving device connected to the reel spool via a chuck or the like so that the distance between the reel drum and the reel spool can be continuously changed as the winding diameter increases. A reel drum / reel spool distance adjustment mechanism that can move the reel spool horizontally downstream, or a mechanism that enables the reel spool to move in an arc shape, or both of these mechanisms are provided. Is a preferred form.

  After a predetermined amount of paper sheet has been wound on the reel spool, winding of the next reel spool is started.

  After the paper sheet is wound on the spool by a predetermined amount, winding is started on the new spool. From the viewpoint of improving productivity and operability, the new spool is automatically It is preferable that an automatic frame changing device capable of starting winding is installed. In this automatic frame change, a new spool is moved from a spool placement location, supported by a chuck connected to a drive device, moved to a specified position, and after the spool starts rotating, the traveling paper sheet is moved. This means that a series of operations for cutting and starting winding of a running sheet on a new spool is automatically performed in a predetermined sequence.

  When starting winding on a new spool, the surface of the new spool is rotated in order to improve the winding form without deteriorating operability, such as by reducing the speed of the traveling paper sheet. A reel spool is driven by a center drive system on a support mechanism called a primary arm, and the speed is brought into contact with a running paper sheet after being synchronized with the running speed of the paper sheet to form a nip with the reel drum. Later, the running paper sheet is cut and started to be wound on a new spool.

  In addition, in order to start winding on a new spool, it is necessary to cut the running paper sheet once. As a method adopted from the cutting of the running paper sheet to the winding process to the new spool, flying Examples thereof include a cutter method, a method of creating a slit by a spot knife and blowing air, a method of only air blowing, a water jet method, or a combination thereof.

  In an air blowing method, which is one form of means for cutting a traveling paper sheet, the paper sheet is cut by the pressure of air sprayed on the traveling paper sheet. The pressure of the air to be blown, the time, and the blowing pressure profile in the width direction can be controlled, and the air blowing pressure is also changed corresponding to the basis weight change of the paper sheet. A single air blowing nozzle may be used, but it will start the process of reliably cutting the running sheet and starting to be surely wound on a new spool after cutting, as well as for the piece of paper that may occur at the time of cutting. A plurality of them may be used for the purpose of preventing scattering. When a plurality of nozzles are used, different air blowing pressures, lengths, positions, moving speeds, moving ranges, etc. may be used as necessary.

  In the water jet system, a running paper sheet is cut by high-pressure water ejected from the nozzle tip. The number of nozzles may be one, but it is preferable to have two or more nozzles in order to improve efficiency. In addition, it is preferable that the nozzles be movable at least in the width direction because the number of nozzles used can be reduced. When a plurality of water jet nozzles are used, different water jet spraying pressures, lengths, positions, moving speeds, moving ranges, etc. may be used as necessary.

  In order to cut a wide and high-speed paper sheet, a combination of a water jet method and an air blowing method is most preferable from the viewpoint of operability and prevention of scattering of paper pieces to the periphery.

  The cut traveling paper sheet starts to be wound around a new spool. As a means for starting the winding, there is a method in which the leading end of the cut traveling sheet is wound around the spool by an air jet. It is done. Further, in order to ensure winding around a new spool, it is also preferable to spray an adhesive or a liquid containing an adhesive on the downstream end of the cut traveling sheet and then wind it around the spool with an air jet. Take as an example.

  After the winding of the paper sheet onto the reel spool is started by being supported by the primary arm, the primary arm moves to keep the distance between the reel spool and the reel drum optimally until a predetermined winding diameter is reached. The reel spool continues to be supported by the primary arm. After the winding has reached a predetermined diameter, the reel spool support is transferred to the secondary arm, but when transferring the reel spool support from the primary arm to the secondary arm, to prevent paper breakage and winding form failure, The nip pressure between the primary arm and the reel drum is decreased continuously or stepwise, and the nip pressure between the secondary arm and the roll drum is increased continuously or stepwise. After the transition from the primary arm of the reel spool support to the secondary arm is completed, winding of a desired diameter can be obtained with the reel spool finally supported by the secondary arm. The obtained winding is sent to the next stroke, but in order to improve operability, a mechanism for automatically conveying the winding on the secondary arm to the next stroke is provided when transporting to the next stroke. It is preferable.

  In the production of the specific pulp used in the present invention and the roll-up by the center drive roll method, the average particle diameter is 0.2 to 0.2 as the pigment contained in the outermost pigment coating layer formed in the coating process. It is preferable to contain kaolin in the range of 1.2 μm in an amount exceeding 60% by mass of the total pigment in the outermost pigment coating layer because an effect of greatly reducing the cosmetic stain can be obtained. Furthermore, by containing at least 5% by mass or more of the delaminated kaolin among the kaolins, the scumming appearance is greatly reduced while having a matte appearance, and the print quality (print smoothness) It is more preferable because an excellent effect can be obtained. The average particle size referred to here is the measurement of X-ray transmission particle size distribution by subjecting each pigment to ultrasonic dispersion treatment so that the dispersion concentration of kaolin to be measured is 8% by mass in a 0.1% aqueous solution of sodium pyrophosphate. It is a particle diameter corresponding to a 50% value from weight cumulative distribution data measured with an apparatus (model name: Cedigraph-5100, manufactured by Micromeritics, USA).

  The kaolin used as the outermost pigment coating layer pigment of the present invention is kaolin that is usually used for printing coated paper, and includes delaminated kaolin and structured kaolin with a processed particle shape. And in this invention, the kaolin of a specific average particle diameter and a compounding quantity are selected in the said kaolin, and the kind and compounding quantity of a kaolin are selected and used. It should be noted that calcined kaolin obtained by high-temperature treatment of kaolin is not preferable because there is a risk of worsening the cosmetic stain.

  The delaminated kaolin contained in the outermost pigment coating layer contains 5% by mass or more in the kaolin contained in the outermost pigment coating layer, preferably 10% by mass or more, and 20 The mass% or more is more preferable. It is also possible to use delaminated kaolin for all pigments in the outermost pigment coating layer.

  In the particle size distribution of the delaminated kaolin, (a) the proportion of particles smaller than 5 μm is 90-100% by mass, (b) the proportion of particles smaller than 2 μm is 70-90% by mass, (c) from 1 μm The proportion of small particles is preferably 30 to 70% by mass. By using the delaminated kaolin having the above particle size distribution, it is possible to obtain a matte coated paper for printing having the properties of good white paper quality, printing quality and suitability for smearing. The particle size distribution was ultrasonically dispersed in a 0.1% aqueous solution of sodium pyrophosphate so that the dispersion concentration of the delaminated kaolin to be measured was 8% by mass, and an X-ray transmission particle size distribution measuring device (model) Name: Cedigraph-5100, manufactured by Micromeritics, USA).

  In the present invention, the pigment used in the outermost pigment coating layer is not particularly limited in addition to the specific pigment, and examples thereof include various kaolins, talc, heavy calcium carbonate (ground calcium carbonate), and the like. Refined natural mineral pigments, light calcium carbonate (synthetic calcium carbonate), composite synthetic pigments of calcium carbonate and other hydrophilic organic compounds, satin white, lithopone, titanium dioxide, silica, alumina, aluminum hydroxide, zinc oxide, Magnesium carbonate, calcined kaolin, hollow organic pigment, dense organic pigment, plastic pigment, binder pigment, plastic bead, microcapsule, and the like can be appropriately mixed and used as long as the effects of the present invention are not impaired.

  The binder used in the coating layer includes starch purified from natural plants, hydroxyethylated starch, oxidized starch, etherified starch, phosphate esterified starch, enzyme-modified starch and cold water soluble starch obtained by flash drying them. Natural polysaccharides such as dextrin, mannan, chitosan, arabinogalactan, glycogen, inulin, pectin, hyaluronic acid, carboxymethylcellulose, hydroxyethylcellulose, and oligomers thereof, and modified forms thereof. Furthermore, natural polymers such as casein, gelatin, soybean protein, and collagen, and modified products thereof, and synthetic polymers and oligomers such as polylactic acid and peptides can be mentioned. In addition, copolymer latex such as styrene butadiene, acrylic, polyvinyl acetate, ethylene vinyl acetate, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, modified polyvinyl pyrrolidone, sodium polyacrylate, polyethylene oxide, polyacrylamide, urea Alternatively, water-soluble synthetic compounds such as melamine / formalin resin, polyethyleneimine, polyamide / polyamine / epichlorohydrin, and the like can be given. One or more of these can be used. In addition, the use of a known natural or synthetic organic compound is not particularly limited.

  The thickeners used in the coating solution include water-soluble polymers such as carboxymethylcellulose, carboxypropylcellulose, sodium alginate, methylcellulose, hydroxymethylcellulose, casein, sodium polyacrylate, polyacrylate, styrene maleic acid. Examples thereof include synthetic polymers such as anhydrous copolymers and inorganic polymers such as silicates.

  Furthermore, various auxiliary agents that are usually used, such as dispersants, fluidity modifiers, antifoaming agents, water resistance agents, printability improvers, preservatives, slime control agents, colorants, and the like, if necessary, Those obtained by cationizing these various auxiliaries are preferably used.

  In addition, when there are two or more pigment coating layers, the pigment coating layer formed under the outermost pigment coating layer is coated with an aqueous coating liquid mainly composed of a pigment and an adhesive and dried. Thus, a pigment coating layer is formed.

  The pigment used in the aqueous coating liquid for the pigment coating layer formed under the outermost pigment coating layer is not particularly limited. For example, various kaolins, talc, heavy calcium carbonate (pulverized carbonate) Refined natural mineral pigments such as calcium), light calcium carbonate (synthetic calcium carbonate), composite synthetic pigments of calcium carbonate and other hydrophilic organic compounds, satin white, lithopone, titanium dioxide, silica, alumina, aluminum hydroxide, Zinc oxide, magnesium carbonate, calcined kaolin, hollow organic pigment, solid organic pigment, plastic pigment, binder pigment, plastic bead, microcapsule and the like can be appropriately mixed and used as long as the effects of the present invention are not impaired. Of course, it is not limited to these.

  The binder, thickener, and other auxiliaries used for the pigment coating layer formed under the outermost pigment coating layer are the same as those exemplified as those used for the outermost pigment coating layer. Can be used.

The solid content concentration of the coating material for forming the pigment coating layer is generally adjusted in the range of 20 to 75% by mass. Incidentally, when the coating weight is blank quality coated paper obtained, print quality, and considering the coated suitability, approximately per side 3~40g / ^{m 2,} it is adjusted preferably at about 3 to 30 g / ^{m 2} .

  The coating method for forming the coating layer is not particularly limited. For example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a slot die coater, a gravure coater, and a Chanplex. A coater, a brush coater, a two-roll or rod metalling or blade metalling type size press coater, a bill blade coater, a short dwell coater, a gate roll coater, a spray coater and the like are appropriately used. Of course, these devices may be on-machine or off-machine.

  As a method of drying the coated paint, various heating drying methods such as hot air drying, gas heater drying, high-frequency drying, electric heater drying, infrared heater drying, laser drying, and electron beam drying, which have been publicly known, have been used as appropriate. The

  In the production of the coated paper for printing of the present invention, it is possible to carry out a smoothing treatment with various calendar devices after the formation of the coating layer. Examples of such calendar devices include super calenders and soft calenders. Commonly used calendar devices such as a gloss calendar, a compact calendar, a mat super calendar, a mat calendar, and a roughening calendar can be used as appropriate. As the calender finishing conditions, the temperature of the rigid roll, the calender pressure, the number of nips, the roll speed, the paper moisture before the calender, and the like are appropriately selected according to the required quality. Furthermore, the calendar device includes an off type that is different from the coater and an on type that is integrated with the coater, but can be used in either case. As the roll material of the calendar device to be used, a rigid roll is a metal or a roll whose surface is mirror-finished with hard chrome plating, etc., and an elastic roll is a urethane resin, epoxy resin, polyamide resin, phenol resin, polyacrylate resin, etc. A roll obtained by molding a resin roll, cotton, nylon, asbestos, aramid fiber or the like is appropriately used. In addition, it is also possible to use a suitable combination of a water coating device, an electrostatic humidifier, a steam humidifier, and the like for humidity control and humidification of the coated paper before and after finishing by a calendar.

In the present invention, from the viewpoint of preventing scratches, in the winder step of dividing the winding wound after forming the coating layer on the base paper or after performing the smoothing treatment after forming the coating layer, A single drum winder type is preferred. By using a single drum winder, damage due to the nip pressure applied to the surface of the coating layer can be minimized, and as a result, the occurrence of scratches can be prevented.
Hereinafter, the winder will be described in detail.

  When surface treatment is performed with a multi-nip calender, or when multi-nip calender processing is not performed, winding after coating with a coating device, or coating with a coating device is not performed with a paper machine Winding that has undergone papermaking, drying, and size pressing is processed by a winder as necessary. The winder has a winding unit installed in the unwinding unit (hereinafter, the winding unit installed in the unwinding unit is referred to as an original winding unit), and a paper or resin hollow roll (hereinafter referred to as a winding unit) disposed in the winding unit. The cutting process is arranged before reaching the paper tube of the winding unit so that the winding length or width of the original winding is the desired length and width. Is used for the purpose of winding on a paper tube (hereinafter referred to as finishing winding). For this purpose, the winder is also provided with a cutting means called a slitter, which can cut to any desired paper width.

  In a two-drum winder, which is a form of winder, the finish winding that is wound around a new paper tube in the winder section is held and finished on two drums. Problems such as occurrence of wrinkles in winding, uneven end face due to shift in the winding position in the width direction, and limitation of the maximum diameter of finish winding are likely to occur. A single drum winder is preferably used as the winder in order to cope with the recent increase in winder processing speed or increase in the diameter of finish winding. In particular, it is preferable to use a single drum winder from the viewpoint of preventing scratches on the surface of the finished paper product.

  An example of the single drum winder is a rider roll support type. Examples of the rider roll support type include a configuration example in which the rider roll and the rear drum are in contact with the finish winding. In the rider roll support type, the finish winding is supported by the rider roll and the rear drum (hereinafter, a combination of the finish winding including the paper tube and / or the paper tube, the rear roll, and the rider roll is referred to as a winder portion). Unlike the two-drum winder, the pressing pressure of the rider roll and the rear drum can be arbitrarily adjusted. Therefore, the nip pressure can be adjusted freely, and the problem that occurs in the two-drum winder hardly occurs, which is preferable.

  As a rider roll, a loop is formed by a single roll type in which only a single roll is in contact with the finish winding, and a belt, preferably a seamless belt, between the two rolls. The belt type etc. which a belt contacts can be illustrated. The rider roll is placed only in one direction, such as the horizontal or vertical direction, with respect to the center of the paper tube, and the rider roll position is held at a fixed angle with respect to the vertical direction of the finish winding center. The rider roll can move in an arc shape, and the distance and angle from the rider roll and the finish winding center can be changed in a desired manner in response to changes in the finish winding diameter. Therefore, it is possible to improve the operability.

  The roll material used for the single roll type of rider roll can be made of metal, resin, ceramic, etc., and different materials such as resin and rubber should be placed on the rider roll surface as necessary. However, it is preferable that the surface of the rider roll is made of rubber in order to prevent scratches in finishing winding. Furthermore, narrow grooves with narrow and deep grooves are spirally formed on the rider roll surface, and wide grooves with wide shallow grooves are formed in a spiral shape overlapping the narrow groove, or rubber is placed on the rider roll surface. In addition, by providing a belt-like protrusion on the rubber surface and winding the belt-like protrusion on the surface of the rider roll in a ring shape or a spiral shape, the effect of preventing air entrainment in the finish winding and the finish winding Since it can contribute also to vibration prevention, it can illustrate as a preferable form.

  As a rider roll, a belt is formed between two rolls by a belt, preferably a belt without joints, and the belt type in contact with this belt for the final winding is the roll type in the single roll type. Since the belt comes into contact with the contact with the belt, the contact area is widened, and the linear pressure at the place of contact can be kept low compared to the single roll type with the same operability. It can be said that this is a preferable form from the viewpoint of preventing surface scratches. As the belt, it is preferable to use a material having air permeability in order to prevent air from being caught in the finish winding.

  A rear roll constituting the winder together with the rider roll is disposed downstream of the finish winding and supports the finish winding. Although it is possible to use a single roll as the rear roll, it is preferable to use a plurality of rolls in order to divide the finish winding in the width direction. As a method of arranging a plurality of rear rolls, a method of arranging in a winder so that the number of combinations of rider rolls and rear rolls is plural, or arranging a plurality of rear rolls continuously in the width direction on the same shaft, Each rear roll can be rotated in any rotation direction, or can be exemplified by a configuration in which the rotation direction can be reversed between the odd and even numbers from the end.

  As the material of the winder rear roll, it is preferable that at least the rear roll surface is rubber because the roll is in direct contact with the finish winding. In addition, from the viewpoint of preventing air entrainment in the finish winding, the rubber surface of the rear roll surface is formed in a narrow narrow groove with a narrow narrow groove, and the wide shallow shallow groove overlaps the narrow groove. Preferably, a belt-like protrusion is provided, a belt-like protrusion is provided, and the belt-like protrusion is wound around the surface of the rear roll in a ring shape or a spiral shape, or is subjected to hole processing. . Moreover, as a roll diameter of a rear roll, it is common to use a thing with a diameter of 600-1500 mm.

  In the winder unit, the paper tube is driven by a driving device connected to the paper tube via a chuck or the like, and the paper can be taken up by this driving force. Further, when the original winding is divided into a plurality of desired numbers in the width direction with a desired width, each of the desired number of paper tubes is held by the chuck so that all the plurality of paper tubes have the same speed. Driven. Moreover, the distance from the center of the paper tube to the rear roll has a paper tube / rear roll distance adjustment mechanism that is continuously changed as the finish winding diameter increases, so that the nip pressure fluctuation of the winding by the rear roll can be changed. This is a preferable mode. Examples of the distance adjusting mechanism include a configuration in which the chuck unit that is connected to the driving device and holds the paper tube is movable in the horizontal direction so that the distance from the rear roll is increased as the winding diameter increases. it can.

  Besides the driving by the driving device connected to the chuck portion holding the paper tube, it is also possible to drive the rear roll and / or the rider roll to obtain the finish winding, all of which are driven. It is also possible to use what has been done. When a plurality of drive systems are present in the winder, it is preferable to perform control so that the respective drive speeds are the same in order to improve the finish winding state.

  When splitting the original winding into multiple finish windings, it is physically impossible to place multiple winder parts on a straight line from the finish winding end to the odd and even finish windings. Therefore, it is necessary to adjust the winder position. For example, when a single rear roll is used, a winder portion corresponding to the even-numbered finish winding is provided upstream from the end when the winder portion corresponding to the odd-numbered finish winding is viewed from the original winding. A method of alternately installing on the downstream side can be exemplified. Moreover, it can also be set as the form which uses a some rear roll, for example, when using two rear rolls, the winder part containing the 1st rear roll corresponding to odd-numbered finish winding from an edge part is used as the origin. A method of alternately installing a winder unit including a second rear roll corresponding to the even-numbered finish winding on the upstream side when viewed from the winding, or further downstream of the first rear roll A method of arranging the second rear roll on the side and adjusting the distance between the two rear rolls and the corresponding winder position can be exemplified.

  Further, even in a form in which the paper tube is not held by the chuck connected to the drive system, the winding in the winder portion is possible, and the paper tube can be held and wound only by the rear roll and the rider roll. In this case, since the positioning accuracy of the paper tube at the start of winding tends to be reduced with a single roll type as the rider roll, it is preferable to use a belt type rider roll.

  Division into a desired width in the winder can be performed by cutting with a slitter. For the cutting with a slitter, a shear cutting method using upper and lower rotary blades is often employed, but the invention is not limited to this. The material of the slitter knife used in the cutting process is made of metal such as alloy tool steel (SKD), high speed steel (SKH), silicon carbide (SiC), silicon nitride (Si3N4), alumina (Al2O3) And ceramics such as zirconia (Y-TZP, PSZ), and ceramic composites (for example, zirconia-alumina composite: ZrO2-Al2O3). The upper blade and the lower blade may be made of the same material or different materials. For example, an example of using a metal blade as the upper blade and a ceramic blade or a ceramic composite blade as the lower blade can be exemplified. .

  In a winder, the original winding is set to a finish winding with a shorter length, and once the finishing winding is finished, a frame change operation for replacing the paper tube occurs. Decrease or stop. For this reason, it is necessary to use a plurality of winders for one series of paper machines and coating apparatuses, or to increase the processing speed of the winder preferably from that of the paper machines and coating apparatuses from the viewpoint of equipment installation. For this reason, a winder having a maximum processing speed of 2000 to 3000 m / min is preferably used.

  Since the frame changing work that occurs in the winder part frequently occurs in actual production, the production efficiency is reduced by human response. For this reason, in order to improve production efficiency, part of automatic paper splicing device for original winding, change of paper tube, tape application at the time of unwinding to the paper tube, tape application of tail part of finish winding, Alternatively, a winder equipped with an automatic frame changing device that can perform all the operations automatically is preferable.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these ranges. In the examples, “parts” and “%” indicate “parts by mass (solid component)” and “mass%” unless otherwise specified.

(Pulp average fiber length and average fiber width)
Using a fiber laboratory (Metso Automation Co., Ltd.), the length weighted average fiber length and the average fiber width of the pulp were measured.

(Blank gloss)
Using a gloss meter (model: GM-26D, manufactured by Murakami Color Research Laboratory Co., Ltd.), according to ISO 8254-1 (1999), the result of measurement under the condition of an incident angle / reflection angle of 75 degrees is a blank paper gloss level. It was.

(Print smoothness)
Using a RI printer, printing was performed once on white paper using 0.6 cc of printing ink (trade name: Varius G ink S type, manufactured by Dainippon Ink Co., Ltd.) to obtain a printed matter. This printed matter was left to dry for 48 hours in an atmosphere having a temperature of 23 ° C. and a relative humidity of 50%. Thereafter, the smoothness of the printed surface was visually evaluated according to the evaluation criteria of 5 (excellent) to 1 (inferior). Evaluations of 2 or less have practical problems.

(Cosmetic dirt suitability)
Using a RI printer, printing was performed once on white paper using 0.4 cc of printing ink (trade name: Varius G ink S type, manufactured by Dainippon Ink, Inc.) to obtain a printed matter. This printed matter was left to dry for 24 hours in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. Then, using a friction fastness tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the printing surface of each printing paper and the surface of the white paper coating layer are stacked facing each other, and a reciprocating friction of 4.9N is applied. The density of the ink stain transferred from the printing surface to the surface of the white paper coating layer was visually evaluated according to the evaluation criteria of 5 (excellent) to 1 (inferior). Evaluations of 2 or less have practical problems.

(Evaluation of cosmetic gloss and cosmetic scratches)
White paper was collected from the windings divided by the winder, and the appearance of the cosmetic gloss and the scratch on the white paper of 10 m ² was evaluated visually according to the evaluation criteria of 5 (excellent) to 1 (inferior). Those with an evaluation of 2 or less are problematic in practice.

Example 1
(Preparation of base paper)
Using a Lo-solids digester (manufactured by Andritz Co., Ltd.), hardwood chips composed of Acacia mangum: eucalyptus grandis = 30: 70 (mass ratio) were kraft-cooked by the Lo-solids cooking method. White liquor with a sulfidity of 28% is prepared, and the white liquor addition rate is 10% per chip dry weight with respect to the chip supply system, 8% in the cooking zone, and 2% in the washing zone as active alkali. The cooking temperature was 146 ° C. After digesting the chips after cooking, unbleached pulp was obtained through a washing process, a screen process, and a washing process again.

  To the unbleached pulp, 1.7% of caustic soda and 1.8% of oxygen per weight of dry pulp were added, and two-stage alkaline oxygen bleaching was performed under the conditions of a pulp concentration of 10% and 98 ° C. for 50 minutes. Caustic soda was added all at once in the first stage, and oxygen gas was added in 1.0% in the first stage and 0.8% in the second stage. The pulp after alkaline oxygen bleaching was washed in the washing step.

  After 1.2% sulfuric acid was added to the pulp after the alkali oxygen bleaching and the pulp concentration was 10%, 60 ° C. and 60 minutes, the pulp was washed in the washing step. Next, after adding 0.5% ozone and 0.5% chlorine dioxide per weight of dry pulp, medium concentration ozone / chlorine dioxide bleaching was performed under the conditions of pulp concentration 10%, 58 ° C., 60 minutes, then washed. It was washed in the process. Next, 1.0% caustic soda and 0.1% hydrogen peroxide per weight of dry pulp are added, and after alkali extraction under conditions of pulp concentration 10%, 60 ° C, 90 minutes, washing treatment is performed in the washing step. did. Finally, 0.2% chlorine dioxide is added per weight of dry pulp, and chlorine dioxide bleaching is performed under conditions of 10% pulp concentration, 70 ° C. and 120 minutes, and then washed in the washing step to obtain bleached pulp A. Got. The resulting bleached pulp A had an ISO whiteness of 90.1%, a length-weighted average fiber length of 0.68 mm, and an average fiber width of 16.0 μm.

After adding light calcium carbonate (trade name: Tama Pearl TP-121, manufactured by Okutama Kogyo Co., Ltd.) as a filler to 100% of the bleached pulp A slurry, the total solid content of the pulp slurry is 10%. On the other hand, aluminum sulfate 0.5%, cationic starch (trade name: Ace K100, manufactured by Oji Corn Starch Co., Ltd.) 0.5%, alkyl ketene dimer sizing agent (trade name: Size Pine K-287, manufactured by Arakawa Chemical Industries) 0 0.1% polyacrylamide (trade name: Polystron 851, manufactured by Arakawa Chemical Industries, Ltd.) 0.2% was sequentially added to prepare a paper stock. Forming a paper layer by a gap former of this stock in operating machine speed 1500 m / min, after dewatering in a shoe press 2 group, and dried in a multi-cylinder dryer, once the base paper basis weight 53 g / m ² Winded up.

(Preparation of pigment coating solution for undercoat layer)
8 parts of starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) as an adhesive to 100 parts of pigment in a pigment slurry made of heavy calcium carbonate (trade name: Hydrocurve 60, manufactured by Bihoku Flour Industries) Then, 4 parts of styrene-butadiene copolymer latex (trade name: OJ-2000, manufactured by JSR) is added, an antifoaming agent and a dye are sequentially added as auxiliary agents, and water is finally added to finally add solid content. A pigment coating solution for an undercoat coating layer having a concentration of 63% was prepared.

(Preparation of pigment coating solution 1 for top coating layer)
In a pigment slurry made of heavy calcium carbonate (trade name: Hydrocurve 90, manufactured by Bihoku Flour & Chemical Co., Ltd.), 100 parts of pigment, 10 parts of starch (trade name: Ace A, supra), styrene -Add 3 parts of butadiene copolymer latex (trade name: OJ-2000, supra), add antifoaming agent and dye sequentially as an auxiliary agent, and add water to make the final solid concentration 63% A pigment coating solution for the top coating layer was prepared.

(Create coated paper for printing)
Using the blade coater for supplying the coating liquid for the undercoat coating layer obtained above to the base paper (basis weight 53 g / m ² ) obtained above by the jet fountain method, Coating and drying were performed so that the dry coating amount was 8 g / m ^2, and an undercoat layer was formed on both sides of the base paper. Next, using a blade coater that supplies the coating liquid 1 for the top coating layer obtained above to the undercoating layer by a jet fountain method, the dry coating amount per side is 8 g / After coating and drying to m ^2, and providing an overcoat layer on both sides, multi-nip calendering is performed, and two pigment coating layers per side with a basis weight of 85 g / m ^{2 in} the center drive method A roll of matte coated paper for printing was obtained. The obtained roll-shaped printing coated paper was divided into small windings with a two-drum winder type winder to obtain a matte coated paper for printing.

Example 2
Matte coated paper for printing is obtained in the same manner as in Example 1 except that the pigment coating solution 1 for the topcoat layer of Example 1 is changed to the pigment coating solution 2 for the topcoat layer described below. It was.

(Preparation of pigment coating solution 2 for top coating layer)
Sodium kaleacrylate (trade name: Aron T-50, manufactured by Toa Gosei Co., Ltd.) as a dispersant is added to an aqueous solution in which 0.1 part is added to the kaolin to be dispersed. 20 parts in diameter 0.24 μm, manufactured by Huber), 10 parts delaminated kaolin (trade name: kao white, average particle diameter 0.76 μm, manufactured by Seal), heavy calcium carbonate (trade name: Hydrocurve 90, Bihoku) 70 parts) (manufactured by Powdered Industries Co., Ltd.) was added and dispersed with a Coreless disperser to prepare a pigment slurry. In this pigment slurry, 4 parts of oxidized starch (trade name: Oji Ace A, supra), 8 parts of styrene-butadiene copolymer latex (trade name: OJ-2000, supra), and 100 parts of pigment, A defoaming agent and a dye were sequentially added as auxiliary agents, and water was further added to finally prepare a pigment coating solution for an upper coating layer having a solid content concentration of 63%.
The particle size distribution of kao white was as follows.
(A) 95% by mass of particles smaller than 5 μm.
(B) Particles smaller than 2 μm 76.2% by mass.
(C) Particles smaller than 1 μm 57.8% by mass.

Example 3
The pigment in the pigment coating solution 2 for the top coat layer of Example 2 is 30 parts fine kaolin (trade name: Hydra Gloss 90, supra), delaminated kaolin (trade name: kao white, supra) 40. Matte coated paper for printing was obtained in the same manner as in Example 2 except that the amount was changed to 30 parts by weight and heavy calcium carbonate (trade name: Hydrocurve 90, supra).

Example 4
Matte coated paper for printing was obtained in the same manner as in Example 1 except that the winder format after the multi-nip calendering process in Example 3 was changed from the two-drum winder format to the single-drum winder format.

Comparative Example 1
In Example 1, the same operation as in Example 1 was performed except that hardwood chip acacia mangum: Eucalyptus grandis = 30: 70 (mass ratio) was changed to birch = 100 and the cooking temperature was changed to 157 ° C. Bleached pulp B was obtained. The resulting bleached pulp B had an ISO whiteness of 89.2%, a length-weighted average fiber length of 0.76 mm, and an average fiber width of 20.2 μm. Further, a matte coated paper for printing was obtained in the same manner as in Example 1 except that bleached pulp A was changed to bleached pulp B in Example 1.

Comparative Example 2
Matte coated paper for printing was obtained in the same manner as in Example 1 except that the reel type in Example 1 was changed from the center drive type to the surface winder type.

  Table 1 shows the evaluation results of the matte coated paper for printing obtained in the examples and comparative examples.

  As is apparent from Table 1, according to the present invention, a coated paper with less generation of scumming stains and shine gloss and no scratches can be obtained as a matte coated paper for printing.

Claims (4)

  In a method for producing a matte coated paper for printing in which at least one surface of a base paper is provided with at least one coating layer mainly composed of a pigment and an adhesive, 50% or more of bleached pulp used for the base paper is eucalyptus. The pulp is made from wood and / or acacia, and the bleached pulp is pulped by a kraft cooking method in which a cooking liquor is added in portions, and further produced in a multistage bleaching process including an ozone bleaching stage. And once the base paper made with the stock containing the bleached pulp is wound up, the coating layer is formed in the process of drawing out again and coating and drying the coating liquid, or the coating layer is formed. Then, after smoothing is performed, it is wound up in a roll shape in the form of a center drive, and a method for producing matte coated paper for printing.   Among the coating layers formed on the base paper, the pigment contained in the outermost pigment coating layer is kaolin having an average particle diameter in the range of 0.2 to 1.2 μm, and the outermost pigment coating layer. 2. The production of matte coated paper for printing according to claim 1, comprising more than 60% by mass of the total pigment, and 5% by mass or more of the kaolin being delaminated kaolin. Method. The method for producing matte coated paper for printing according to claim 2, wherein the delaminated kaolin satisfies all the following conditions (a) to (c).
(A) The ratio of particles smaller than 5 μm is 90 to 100% by mass.
(B) The proportion of particles smaller than 2 μm is 70 to 90% by mass.
(C) The proportion of particles smaller than 1 μm is 30 to 70% by mass.   The matte coating for printing according to any one of claims 1 to 3, wherein in the winder step of dividing the roll wound in the center drive format, the winder is in a single drum winder format. Paper manufacturing method.