JP2007186800A - Regenerated particle-filled paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper having high ash yield during papermaking, free from wear and deterioration of papermaking facilities and stain of printing facility, produced by cyclic usage of resources and scarcely causing breakage of paper. <P>SOLUTION: The paper is composed of pulp and filler as main component raw materials. In the paper, pulp is composed of 50-100 mass% waste paper pulp and at least filler is internally added to the pulp and regenerated particle aggregate from particles obtained without causing aggregation after dehydration, drying, calcination, pulverization of filler using deinked floss discharged from treating process of waste paper as a main raw material is used as at least filler for internal addition and the filler is contained in an amount of 4-35 mass% as paper ash in the paper, and opacity of white paper is 91-95% and hot water extract pH is 6.0-9.5 and regenerated particle aggregate contains Ca, Si and Al and the components of regenerated particles contain Ca, Si and Al in a mass ratio of (40-82): (9-30): (9-30) expressed in terms of oxide by an elementary analysis and total content of Ca, Si and Al is ≥93 mass% based on components of regenerated particles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to paper. More specifically, it is a resource-recycled paper that collects and uses raw pulp and filler, which are the main components of paper, from waste paper, and relates to paper such as newsprint, publishing paper, and book paper.

  Due to environmental problems in recent years, there has been a movement to collect waste office paper generated from offices throughout the building for the purpose of environmental protection, resource protection, and garbage reduction, and the use of recycled paper using waste paper pulp has been seen. With the increase, the ratio of used paper to paper is also increasing. In addition, from the viewpoints of resource saving, transportation cost reduction, and raw material cost reduction, the weight of each paper is increasing year by year. Furthermore, at the paper mills, the production ratio of recycled paper using recycled paper pulp and the percentage of recycled paper are increasing, and the production speed of the paper manufacturing process is increasing more and more to improve production efficiency.

  For the use of paper, not only demands for strength such as tensile strength that can withstand high-speed rotary printing, but also high-definition and good-looking printing, as the printing press speeds up, multicolors, and printing accuracy improve. The finish is strictly demanded. In particular, when solid printing is performed, the level of demand is increasing year after year for the phenomenon that the printing contour and image can be seen through from the opposite surface due to low opacity, so-called back-through and deterioration in concealment.

  However, with the widespread use of recycled paper, recently recycled paper, which is recycled paper, has been reused, that is, pulp fiber is repeatedly reused. There is a tendency for the quality to gradually decline. For this reason, the strength of the paper and the opacity are reduced, and there is a problem of the show-through and concealment during printing.

  Therefore, in order to solve the above-described problem of lowering opacity and reduce paper back-through, a method of increasing the opacity and oil absorption of the paper by increasing the filler is known. Many attempts have been made to use carbon and calcium carbonate. For example, a paper containing pulp and calcium carbonate is made by adding white carbon to make a paper, and a filler-added paper in which oil absorption, pore volume, average particle diameter, etc. of hydrated silicic acid are set within a specific range ( Patent Document 1), and newspaper paper (see Patent Document 2) in which white carbon and calcium carbonate are mainly used and the proportion of ash in the ash content is set within a specific range.

  In the filler-added paper and newsprint, white carbon is often used as a filler, and therefore, the opacity and oil absorption are certainly improved as compared with the conventional one. However, when calcium carbonate is frequently used, there arises a problem that the papermaking equipment is easily worn and deteriorated, and white carbon is expensive in the first place, leading to an increase in cost. Moreover, when white carbon is frequently used, there is a problem that paper dust is likely to be generated and printing equipment contamination is easily caused.

  On the other hand, in paper mills, the yield of fine fibers has increased due to the rapid and forced dehydration at the wire part due to the high blending of waste paper pulp with a lot of fine fibers, the weight reduction of paper, and the speedup of paper machines in recent years. The yield of ash is extremely low, and paper sludge such as drainage and dewatered sludge discharged from each paper making process is increasing.

  Furthermore, due to the increase in the production ratio of recycled paper using waste paper pulp and the high blending of waste paper pulp, a lot of waste paper pulp is required, and the amount of waste paper used is increasing. Waste paper such as newspaper and magazine waste paper contains a lot of inorganic substances derived from fillers used in uncoated paper and fillers and pigments used in coated paper. The amount of deinking floss that is separated from pulp fibers and contains a large amount of inorganic fillers and pigments is increasing.

  Paper sludges such as deinking floss discharged from waste paper processing processes that contain a large amount of inorganic fillers and pigments, and wastewater and dewatered sludge discharged from each paper manufacturing process have been conventionally burned and reduced in volume. And many have been landfilled. However, in order to continuously manufacture while maintaining and improving the quality of recycled paper that can contribute to environmental protection, resource protection, and dust reduction by the above-mentioned background technology, the paper mill can recycle and effectively use this paper sludge. Usage has become a major issue.

  Since the paper sludge contains a large amount of inorganic matter, a large amount of combustion ash (inorganic matter) remains even when burned, and the effect of volume reduction is low. Therefore, efforts such as utilizing this combustion ash as a raw material for cement and soil improvement have been made, but in these methods, combustion ash is used as an auxiliary agent and is not used in large quantities. Eventually, most of the combustion ash is landfilled.

  It is conceivable to use the combustion ash as an internal filler for paper, but the combustion ash is not suitable for use as an internal paper filler because it has low whiteness. .

  Thus, a method has been proposed in which combustion ash (incineration ash) is reburned, and slurries and wet dispersion are performed to improve whiteness to obtain a white pigment (see Patent Document 3).

  However, in the case of the method of reburning the incinerated ash, it is necessary to set the reburning temperature to 500 to 900 ° C. in order to completely burn the unburned carbon, and the whiteness of the incinerated ash is about 50%. It has been found that it is not suitable for use as a paper filler. It has also been found that when the re-combustion temperature is set to over 900 ° C., the combustion ash (inorganic material) is sintered and melted and becomes extremely hard. In addition, when reburned ash is used as a filler for paper, this reburned ash has very hard properties, so the papermaking wire wears out quickly and its life is very short. I could not.

  For such papermaking wire wear, it is conceivable to pulverize the reburned ash and reduce its particle size to reduce wear and improve smoothness, but when used as an internal filler for paper. However, there is a problem that the energy cost for pulverization becomes extremely high because the yield during paper making is low and the reburned ash itself is extremely hard.

  Also, as a method of using paper sludge, water-containing paper mill waste sludge containing organic matter from paper fibers is supplied into a reactor into which oxygen-containing gas has been injected, and is heated to about 250 to 300 ° C. and 3000 psig (psig). There has been proposed a method of regenerating the inorganic substance in the waste sludge as a papermaking pigment (inorganic filler) by oxidizing under pressure for 0.25 to 5 hours (see Patent Document 4).

  However, since the above method is based on wet air oxidation treatment of papermaking sludge, organic matter removal is not sufficient, and the obtained pigment has low whiteness and irregular particle sizes, and is used as a filler for papermaking. However, there is a problem that the reaction operation is complicated and expensive.

  In addition to the above, a method has been proposed in which papermaking sludge is baked into PS charcoal and then incinerated with a kiln to produce white clay as a papermaking raw material (see Patent Document 5).

  However, since the papermaking sludge is baked in the above-described method, there is a great demerit that not only energy cannot be effectively extracted from the papermaking sludge but also input energy is required. Furthermore, the generated white clay also has a problem that the particle size is uneven and large, and cannot be used as a papermaking filler.

  Furthermore, a method of producing a paper filler by adding a flocculant to the waste water and granulating the resulting sludge and drying, carbonizing, and firing continuously in a rotary kiln has been proposed (see Patent Document 6). ). In this method, the granulation and shaping are performed prior to firing in order to perform firing uniformly.

  However, for example, when formed sludge having a solid content concentration of 40 to 60% (in other words, moisture content of 60 to 40%) is continuously dried, carbonized, and calcined in a rotary kiln, it depends on the dry state and carbonized state. First, the treatment of sludge particles is forced to proceed by the rotation of the kiln. Therefore, if the drying is insufficient, a large amount of unburned matter remains inside the particles, and as a result, the firing becomes incomplete and the whiteness is lowered. On the other hand, when overdried, the firing is complete but overfired and the hardness of the obtained regenerated particles is increased. Use of the recycled particles causes a problem that wire wear in a paper machine and cutter blade wear when cutting paper are likely to occur.

  For example, the biggest problem of the conventional method described in Patent Documents 3 to 6 for producing a paper filler using papermaking sludge as a raw material is that the papermaking sludge used as a raw material flows out through a wire in the papermaking process. Recovered from wastewater containing solids generated during the washing process in the pulping process, recovered and separated from solids using a solids separator that uses precipitation or flotation in the wastewater treatment process, waste paper Various sludges, such as those from which foreign substances have been removed in the treatment process, are mixed.

  Among the various sludges, for example, a paper strength agent or the like is mixed in sludge that has flowed out through the wire in the papermaking process, and the quality of the sludge varies due to changes in the papermaking process.

  In addition, flocculant is mixed in the sludge collected from the waste water, and the quality of the sludge varies greatly due to papermaking, production fluctuations, and in-process cleaning of the production equipment.

  The sludge generated from the washing process in the pulping process is mixed with substances that are not suitable for paper fillers and pigments, and the quality of the sludge varies due to fluctuations in chip moisture and pulp production conditions.

  Therefore, when various papermaking sludges are used without selection, the quality and quality of the papermaking fillers and pigments are low, and the quality is extremely variable and unstable.

  As described above, all of the conventional methods using papermaking sludge all start with the recovery of papermaking particles, and the regenerated particles from the papermaking sludge obtained by these methods have a quality as a papermaking pigment and filler. It was not suitable and lacked quality stability.

Therefore, although raw paper pulp, which is a major component of paper, is increasingly used in waste paper pulp, conventional white carbon and calcium carbonate must be used frequently as a filler, for example, effectively using unnecessary materials in the papermaking process. Thus, development of a technique capable of improving the opacity and paper strength while reducing costs and improving the wear problem of the papermaking equipment is awaited.
JP-A-9-176985 JP 2002-201590 A JP-A-11-310732 Japanese Examined Patent Publication No. 56-27638 Japanese Patent Laid-Open No. 54-14367 JP 2004-176208 A

  The present invention has been made in view of the above-described background art, and provides a paper for resource recycling that collects and uses pulp fibers, fillers and pigments, which are main components of waste paper (paper), from waste paper. For the purpose. Specifically, the main components of waste paper (paper) are recovered together with pulp fibers and fillers / pigments, and are recycled at low cost using resources, maintaining excellent paper strength and reducing paper breakage. In addition, there is little blanket stain due to paper dust, printing white spots, etc., ink absorption, excellent opacity and little show-through, and paper that can be used suitably for printing in, for example, offset printing, etc. With the goal.

  That is, the present invention is a paper having raw material pulp and filler as main constituent raw materials, wherein the raw material pulp is composed of 50 to 100% by weight of waste paper pulp, and at least the filler is deinked floss as a main raw material. Recycled particles obtained through a drying step, a firing step and a pulverization step, containing calcium, silicon and aluminum, and having a total content of calcium, silicon and aluminum of 90% by mass or more in terms of oxides by elemental analysis Relates to a paper in which is used.

  The paper of the present invention has a high ash yield at the time of paper making, is produced at low cost by recycling resources, hardly causing wear deterioration of the paper making equipment such as wire wear and printing equipment dirt, and has excellent paper strength. Not only are paper breaks maintained, but there are few blanket stains and white spots due to paper dust, ink absorption, excellent opacity, and low back-through. For example, newsprint, publishing paper, books The paper can be suitably used for offset printing such as high-speed offset color printing, particularly high-definition printing in high-speed offset printing.

  As described above, the paper of the present invention has raw pulp and filler as main constituent raw materials, and the raw pulp is composed of 50 to 100% by weight of waste paper pulp. At least as a filler, a deinking process using deinked floss as a main raw material, Recycled particles obtained through a drying step, a firing step and a pulverization step, containing calcium, silicon and aluminum and having a total content of calcium, silicon and aluminum of 90% by mass or more in terms of oxides by elemental analysis It is used.

  In addition, since pulp fibers, fillers and pigments, which are the main components of paper, are all recovered, recycled, and reused, the paper that can be provided by the present invention is compared with conventional recycled paper. , Defined as completely recycled paper.

  First, the raw material pulp used for this embodiment is demonstrated. Such raw material pulp is composed of, for example, 50 to 100% by weight of used paper pulp made from used paper such as used newspaper, magazine used paper, imitation / colored used paper, and OA used paper. Thus, in this embodiment, since used paper pulp is 50 mass% or more, it contributes greatly to the effective use of resources and can achieve cost reduction.

  There is no particular limitation on the type of used paper pulp, and examples thereof include dinking pulp (DIP) and waist pulp (WP), and these can be used alone or simultaneously.

  As the raw material pulp, pulp used for ordinary paper can be used as appropriate in addition to the waste paper pulp. Examples of raw material pulp other than waste paper pulp include Stone Grand Pulp (SGP), Pressurized Stone Grand Pulp (PGW), Refiner Grand Pulp (RGP), Chemi Grand Pulp (CGP), Thermo Grand Pulp (TGP), and ground wood. Pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), refiner mechanical pulp (RMP) and other mechanical pulp; softwood kraft pulp (NBKP), hardwood kraft pulp (LBKP) and other chemical pulp; The pulp etc. which bleached these are mention | raise | lifted and it can select and use 1 type (s) or 2 or more types from these.

  As described above, the ratio of the waste paper pulp in the raw material pulp is 50 to 100% by mass, but resource saving and cost reduction are realized, and the bulkiness is higher in maintaining cushioning and comparing the same basis weight. From the point which can acquire property, it is further 60-100 mass%, and it is preferable that it is 70-100 mass% especially.

  Next, the filler used in this embodiment will be described. As such a filler, at least regenerated particles containing deinked floss as a main raw material and containing a specific amount of calcium, silicon and aluminum obtained through a dehydration step, a drying step, a firing step and a pulverization step are used.

  One of the major features of this embodiment is that a specific amount of the regenerated particles is used as a filler, and a specific amount is internally added to the raw pulp containing 50-100% by weight of the waste paper pulp as described above. Since the recycled particles can be recycled and used by firing deinked floss, disposal such as landfill as waste is unnecessary, and greatly contributes to reduction of environment and resource saving. Is. Further, since the raw material is deinking floss generated in the waste paper processing step, there is an advantage that it is inexpensive, the amount of new inorganic particles used can be suppressed, and the manufacturing cost is sufficiently reduced. Furthermore, by using such regenerated particles, the yield of ash during paper making is high, and paper can be manufactured at low cost without causing much wear deterioration of the paper making equipment such as wire wear and printing equipment contamination. Excellent opacity and paper strength equal to or better than the same are imparted to the paper, and there are fewer breakthroughs and paper breaks.

  The regenerated particles used in the present embodiment are obtained through a dehydration step, a drying step, a firing step, and a pulverization step. Furthermore, as will be described later, a deinking floss aggregation process, a granulation process, a classification process provided between the processes, and the like may be performed. In addition, it is desirable to provide various sensors in the production facility for regenerated particles to control the state of the object to be processed and the equipment, the processing speed, and the like.

  Furthermore, in the present embodiment, silica-coated regenerated particles in which the surfaces of the particles obtained through the above-described steps are coated with silica can be particularly suitably used as the regenerated particles internally added to the raw material pulp.

  By further precipitating silica on the surface of the regenerated particles to form silica-coated regenerated particles, in the used paper processing step in the circulation use, it is reacted with sodium hydroxide to react with sodium hydroxide as a buffering agent or a bleaching aid. It can also contribute to recycling. Further, when such silica-coated regenerated particles are internally added to the raw material pulp as a filler, the paper whiteness, opacity, surface strength, ink drying property, and more than when using regenerated particles not coated with silica, Each effect such as ink absorption unevenness and bulkiness can be improved.

  The deinking floss produced in the used paper processing step used in the present embodiment has a tendency to increase the content of calcium carbonate with the recent neutral paper making, and the ratio of calcium in the obtained regenerated particles is also high. Tend to be. When regenerated particles with a high calcium content are added to the raw material pulp in this way, the opacity of the paper may be slightly reduced, but the silica-coated regenerated particles with silica precipitated on the surface are used as regenerated particles for papermaking. The opacity of the paper obtained by internally adding the silica-coated regenerated particles to the raw pulp is remarkably improved.

  The silica covering the surface of the regenerated particles can be used without particular limitation as long as it is not naturally produced silica but synthetic silica by some chemical reaction. Specific examples include colloidal silica, silica gel, and anhydrous silica. These synthetic silicas make use of excellent properties such as high specific surface area, high gas adsorbing capacity, fineness, permeability to pores and large adsorbing power, high adhesion, and high oil absorption. It is used in a wide range of fields. Among these, colloidal silica has a shape such as a spherical shape, a chain shape, and an amorphous shape, in which impurities are removed from a silicic acid compound to form an anhydrous silicic acid sol, and the sol is stabilized by adjusting pH and concentration. Amorphous silica. Silica gel is hydrous silicic acid obtained by decomposing sodium silicate with an inorganic acid. Anhydrous silica is obtained by hydrolysis of silicon tetrachloride.

  The method for depositing silica on the surface of the regenerated particles to obtain silica-coated regenerated particles is not particularly limited. For example, the following method can be suitably employed. First, regenerated particles are added to and dispersed in an alkali silicate solution, and after preparing a slurry, the temperature of the liquid is maintained at about 70 to 100 ° C., more preferably at a predetermined pressure in a sealed container, while heating and stirring. Add to produce silica sol. Subsequently, silica can be deposited on the surface of the regenerated particles by adjusting the pH of the final reaction solution to a range of 8-11. Silica precipitated on the surface of the regenerated particles in this way, using alkali silicate (for example, sodium silicate: water glass) as a raw material, reacts with a dilute solution of mineral acid such as sulfuric acid, hydrochloric acid, nitric acid at high temperature, Silica sol particles having a particle size of about 10 to 20 nm, obtained by hydrolysis reaction and polymerization of silicic acid.

  In addition, silica sol fine particles having a particle size of about several nanometers, which are generated by adding an acid such as dilute sulfuric acid to an alkali silicate solution such as a sodium silicate solution, cover the entire porous surface of the regenerated particles. The silica is deposited on the surface of the regenerated particles by the bond between the silica sol fine particles on the surface of the inorganic fine particles and the silicon, calcium, or aluminum included in the regenerated particles accompanying the crystal growth of the silica sol fine particles. You can also. In this case, the pH when adding the acid to the alkali silicate solution is in a neutral to weakly alkaline range, and the pH is preferably adjusted in the range of 8-11. This is because if the acid is added until the pH reaches an acidic condition of less than 7, white carbon may be generated instead of silica sol particles.

The type of the alkali silicate solution is not particularly limited, but a sodium silicate solution (No. 3 water glass) is particularly desirable from the viewpoint of easy availability. The concentration of the alkali silicate solution is such that the silica component in the regenerated particles is reduced and the silica content (SiO ₂ equivalent) in the solution is 3 so that silica does not easily precipitate on the surface of the regenerated particles. The silica deposited on the surface of the regenerated particles is preferably white carbon from the form of the silica sol, impairing the porosity of the regenerated particles and insufficiently improving the opacity and toner fixability. In order to eliminate the risk of becoming, it is preferable that the silicic acid content is 10% by mass or less.

  In order to make the particle size of the regenerated particles uniform in each step, classification is preferably performed, and the quality can be further stabilized by feeding back coarse particles and fine particles to the previous step.

  In addition, it is preferable to granulate the deinked floss that has been dehydrated in the previous stage of the drying process, and more preferably to classify the granulated product uniformly so that coarse or fine particles are formed. The quality can be further stabilized by feeding back the grains to the previous process. In granulation, ordinary granulation equipment can be used, and equipment such as a rotary type, a stirring type, and an extrusion type is preferable.

  It is preferable to remove foreign substances other than regenerated particles in the production facility. For example, it is possible to remove foreign substances such as sand, plastic, metal, etc. with a pulper, screen, cleaner, etc. before reaching the deinking process of the used paper pulp manufacturing process. From the viewpoint of removal efficiency. In particular, the iron content is preferably removed by avoiding the mixing of iron content, since it causes the whiteness of the regenerated particles to be reduced due to oxidation. Therefore, each process is designed or lined with materials other than iron to prevent iron from being mixed into the system due to abrasion, etc., and a high-magnetic material such as a magnet is installed in the drying / classifying equipment, etc. In particular, it is preferable to remove iron.

In the present embodiment, in the drying step, the firing step, and the classification step as necessary, the particles having a particle size of 40 μm or less are preliminarily processed to 90% by mass or more before the pulverization step. Is preferred. Accordingly, a single-stage pulverization process by wet pulverization can be performed without performing a multistage pulverization process such as pulverization of coarse particles by dry pulverization and fine particle formation by wet pulverization. Thereby, the peak height of the average particle diameter in the differential curve of the particle size distribution by the Coulter counter method can be set to 30% or more. Furthermore, by adjusting calcium, silicon, and aluminum in the deinking floss as a raw material in advance to a mass ratio described below, for example, the pore volume of the regenerated particles is 0.15 to 0.60 cc / g, the pore surface area Can be ¹⁰ to 25 m ² / g, and the pore radius can be 30 to 100 nm.

  The regenerated particles thus obtained contain calcium, silicon and aluminum. The ratio of these calcium, silicon, and aluminum in the regenerated particles is analyzed by elemental analysis using an X-ray microanalyzer (model number: E-MAX S-2150, manufactured by Hitachi, Ltd./Horiba, Ltd.) and oxidized. Calcium: silicon: aluminum 30-82: 9-35: 9-35, 40-82: 9-30: 9-30, especially 60-82: 9-20: 9-20 A ratio is preferred. In particular, when the regenerated particles are silica-coated regenerated particles, the ratio of calcium, silicon and aluminum is 30 to 62:29 to 55: 9 to 35 in terms of oxides: calcium: silicon: aluminum. It is preferable. At the same time, the total content in terms of oxides in the elemental analysis of calcium, silicon and aluminum is 90% by mass or more, preferably 93% by mass or more.

  Thus, for example, when regenerated particles containing calcium in an amount of 30% by mass or more in terms of oxide are internally added to the raw material pulp as a filler, the whiteness of the obtained paper can be improved.

  In order to adjust the ratio of calcium, silicon, and aluminum in the regenerated particles within the above range, for example, in terms of oxide, it is originally preferable to adjust the raw material composition in the deinking floss. If necessary, in the classification step, it is also possible to adopt a method in which a coating floss with a clear origin or a preparation step floss is contained by spraying or a method in which incinerator scrubber lime is contained.

  For example, neutral papermaking wastewater sludge and coated paper manufacturing wastewater sludge are used to adjust calcium in recycled particles, and newspaper manufacturing systems that are added in large quantities as opacity improvers are used to adjust silicon. For the adjustment of aluminum, a papermaking drainage sludge using an acid papermaking sulfuric acid band or the like, and a drainage sludge from a high quality papermaking process in which a large amount of clay is used can be appropriately used.

  Moreover, in order to adjust the total content of calcium, silicon and aluminum to 90% by mass or more in terms of oxides, for example, means for using a flocculant containing no iron in the agglomeration treatment of drainage sludge, and manufacturing equipment processes other than iron Designed or lined with other materials to prevent iron from being mixed into the system due to wear, etc., and further adopting means to remove iron by installing high magnetic materials such as magnets in the drying and classification equipment Is possible. In particular, iron content is preferably a causative substance that lowers the whiteness by oxidation, and thus is preferably removed selectively.

  By the way, calcium carbonate has homogeneous images such as hexagonal calcite crystals (calcite) and orthorhombic aragonite crystals (aragonite). Most limestones produced in nature are calcite crystals, and shellfish contain aragonite crystals in addition to calcite crystals. Furthermore, although not natural, calcium carbonate also has vaterite crystals. There are various kinds of calcium obtained from the deinking floss, but it becomes a substantially uniform calcium carbonate property by calcination and aggregation. Accordingly, such calcium contributes to the quality stability of the regenerated particles themselves, and the regenerated particles exhibit stable properties while being aggregates composed of different components such as calcium, silicon, and aluminum.

  Further, the regenerated particles contain silicon, but the silica primary particles are fine, so that the optical refractive index is high. Therefore, for example, when regenerated particles containing silicon in an amount of 9% by mass or more in terms of oxide are internally added to the raw material pulp as a filler, the opacity of the obtained paper can be improved.

  Furthermore, since the regenerated particles used in this embodiment have a soft and porous property in which fine particles are secondarily aggregated, they contribute to the formation of a bulky paper layer, and the regenerated particles are internally added to the raw pulp as a filler. The resulting paper has a low density and a good stiffness for handling.

  The particle size of the regenerated particles used in the present embodiment is, for example, secondary particles obtained by agglomerating primary particles, from the viewpoint of yield in raw pulp and prevention of loss of regenerated particles into white water. The average particle size is preferably 0.05 μm or more, more preferably 0.1 μm or more as measured by a counter particle size distribution measuring apparatus (TA-II type, manufactured by COULTER ELECTRONICS). From the viewpoint of preventing clogging, the average particle size is preferably 16 μm or less, and more preferably 15 μm or less.

  When the content of the regenerated particles is too small, for example, in a calendar process in a paper machine, a smoothing effect is hardly expressed, and the opacity after printing is reduced due to a decrease in paper opacity. Further, since the rigidity of the paper is increased and the running property on the rotary press may be lowered, it is preferably 4% by mass or more, more preferably 5% by mass or more with respect to the raw material pulp. On the other hand, if the content of regenerated particles is too high, it is desirable in terms of surface properties and rigidity, but ash tends to fall off during transport in the printing press, resulting in reduced surface strength, peeling, Since printing white spots and paper dust may occur, the content is preferably 35% by mass or less, more preferably 20% by mass or less, based on the raw material pulp.

  In the present embodiment, the regenerated particles can be used alone as a filler, but in addition to this, for example, calcium carbonate such as heavy calcium carbonate and light calcium carbonate, talc, kaolin, etc. Use at least one filler selected from clay such as clay and delaminated clay, inorganic filler such as titanium dioxide, synthetic silica and aluminum hydroxide, synthetic polymer fine particles such as polystyrene resin and urea formaldehyde resin, etc. You can also.

  In addition, when the addition rate of the filler containing regenerated particles is too small, the effect of using the filler is not sufficiently expressed, and conversely, when too large, there is a possibility that the paper strength may be reduced. The paper ash content is preferably 4 to 35% by mass, more preferably 2 to 25% by mass.

  In addition, as additives to be added to the paper slurry obtained from raw pulp and filler, those added to ordinary paper can be used, such as starches, vegetable gums, aqueous cellulose derivatives, sodium silicate, etc. Paper strength enhancers: rosin, starch, CMC (carboxyl methylcellulose), polyvinyl alcohol, alkyl ketene dimer, ASA (alkenyl succinic anhydride), neutral rosin and other internal sizing agents; polyacrylamide and copolymers thereof, silica Examples thereof include a yield improving agent such as sodium acid.

  Furthermore, in this embodiment, after preparing a paper slurry from raw material pulp and making paper, a surface treatment agent containing, as a component, a polymer material such as starch, modified starch, PVA (polyvinyl alcohol), or polyacrylamide is formed on the surface. You may apply | coat or add colorants, such as dye and a pigment, to paper stock slurry.

  The modified starch is not particularly limited, and ordinary starch raw materials are used. Examples thereof include starch obtained by subjecting corn, potato, tapioca, wheat, rice, etc. to oxidation treatment, enzyme treatment, and the like. When the modified starch is used, the amount in the surface treatment agent is preferably adjusted to be 40% by weight or more in the total solid content in order to obtain a desired effect.

  As the surface treatment agent, other adhesives as appropriate, for example, latexes such as styrene-butadiene copolymer, polyvinyl alcohol and polyacrylamide, and pigments such as kaolin and calcium carbonate, antifoaming agents, water-resistant agents, surface Various auxiliaries such as sizing agents and preservatives can also be added. Moreover, the solid content concentration of the surface treatment agent is not particularly limited, and is preferably adjusted to, for example, about 2 to 25% by mass according to the coating apparatus and the coating amount.

  If the surface treatment agent is used in an excessively large amount, not only the cost is increased, but also the adhesiveness of the paper surface called “Nepari” property tends to be expressed when the paper surface is wet. If this sharpness increases, it may increase blanket piling, especially in non-image areas, or the paper surface may stick to the blanket during printing, resulting in running problems such as wrinkles and paper breaks. , Not very preferable. Further, when the amount of the surface treatment agent used is increased, the transparency of the target paper is increased, that is, the opacity is decreased, and the drying property of the ink may be deteriorated. Of these surface treatments, starch and polyacrylamide are widely used because of their relatively low nepariness, but they are both highly soluble in water, so that they can be easily eluted in dampening water during printing. At the same time, it is deposited on the blanket and blanket piling is likely to occur. Also, the eluted surface treatment agent is transferred to and accumulated on the printing plate via the blanket, so that the non-image area of the printing plate becomes sensitized, and ink stains on the non-image area, that is, paper contamination called background contamination, is induced. Therefore, it is not preferable to use a large amount.

  The surface treatment agent is a coating apparatus commonly used in the papermaking field, such as a size press, a blade metering size press, a rod metalling size press, a gate roll coater, a blade coater, a bar coater, a rod coater, an air knife coater, etc. And apply.

The coating amount of the surface treatment agent is preferably adjusted to 0.7 g / m ² or more in terms of dry weight in order to sufficiently improve the surface strength of the paper. In order not to cause a decrease in ink drying property, it is preferable to adjust the dry weight to 2.0 g / m ² or less.

  Thus, the stock prepared from the stock slurry and, if necessary, the additive can be made by a known paper machine, and further passed through a calender device as necessary, followed by pressurization and smoothing treatment. Can be finished into paper. As the calendering device, it is possible to smoothen the paper layer without strongly pressing by using a soft calender with a combination of a metal roll / resin roll rather than a machine calender with a combination of a normal metal roll / metal roll. It is more preferable because the paper layer strength can be sufficiently suppressed.

  The pH at the time of papermaking is such that when calcium carbonate is contained in the filler, for example, the calcium carbonate dissolves to reduce the yield and cause a stain in the papermaking process. From the viewpoint of stability and pH adjustment due to high pH of the papermaking system accompanying high blending, it is preferable to adjust to about 5 to 8.

  The addition of regenerated particles can be performed at any conventional stage, but is preferably performed between the raw material blending chest and the inlet. By adding in the meantime, the regenerated particles are easily dispersed and the fixability to the pulp fiber is improved. As a result, the yield of the filler is improved. Further, since the regenerated particles do not inhibit the binding between the pulp fibers, the stiffness of the paper is not lowered. In order to more uniformly disperse the regenerated particles and improve the fixability to the pulp fiber, it is particularly preferable to add the regenerated particles in the vicinity of the inlet as much as possible.

  The paper thus obtained has a hot water extraction pH of 6.0 or more, more preferably 6.1 or more as measured in accordance with “Test method for pH of paper, paperboard and pulp-water extract” described in JIS P 8133. It is preferably 9.5 or less, more preferably 9.0 or less. When the hot water extraction pH is in such a range, the elution of calcium carbonate contained in the regenerated particles is prevented, the shape of the regenerated particles is stabilized, and the formation of calcium hydroxide is prevented. The generation of paper stains and scales can be suppressed, and paper deterioration can be suppressed and resources can be recycled. In addition, the ink drying property of paper can be improved, the ink absorption unevenness can be reduced, the deterioration can be sufficiently suppressed, and the storage stability and the fixing property of the auxiliary agent can be further improved.

Furthermore, the basis weight of the paper according to the present embodiment is based on the “basis weight measurement method” described in JIS P 8124 from the viewpoint of weight reduction, for example, ensuring the paper quality strength in high-speed rotary printing, and ensuring the printing opacity. Measured, it is preferably 38 g / m ² or more, more preferably 40 g / m ² or more. From the viewpoint of weight reduction, the basis weight is 46 g / m ² or less, and further 44 g / m ² or less. It is preferable. Is less than 38 g / m ^2, for example, ensuring strength in a high-speed offset rotary printing machine is difficult, in the 46 g / m ² or more, recent weight reduction, and thus runs counter to the resource saving.

  The whiteness of the paper varies depending on the application, but in consideration of the appearance as a printed matter, the whiteness of the paper is at least 50% as measured in accordance with “Testing Method for Hunter Whiteness of Paper and Pulp” described in JIS P 8123. The above is preferable, and taking newspaper paper as an example, the whiteness is preferably 52 to 56%, more preferably 53 to 55%.

  The white paper opacity is required to have high opacity from the point of being difficult to see through during printing. However, taking newspaper paper as an example, “Paper Opacity Test Method” described in JIS P 8138 is used. Is preferably 91 to 95%, more preferably 92 to 94%.

The density of the paper is measured in accordance with “Paper and paperboard—Test method of thickness and density” described in JIS P 8118 from the viewpoint of maintaining the strength associated with the recent reduction in weight and weight. It is preferably 55 to 0.60 g / cm ³ , more preferably 0.56 to 0.59 g / cm ³ .

Further, although the stiffness in the MD direction of the paper varies depending on the application, for example, from the viewpoint of imparting a waist suitable for high-speed rotary printing, a “stiffness test method using a paper Clark stiffness tester” described in JIS P 8143. and measured according to, 36.0~39cm ^3/100, preferably further is 36.5~39cm ^3/100.

  Furthermore, considering the paper quality strength in high-speed rotary printing, the surface strength of the paper is preferably at least grade 3 or higher as measured by an RI tester (manufactured by Akira Seisakusho Co., Ltd.) described later.

  As described above, the paper according to the present embodiment is a raw material pulp containing 50% by mass or more of waste paper pulp, the main material is deinking floss generated in the waste paper processing step, and a total of 90% by mass of calcium, silicon and aluminum. The above-mentioned regenerated particles are added and used as a filler. Therefore, the paper according to the present embodiment has a high ash yield at the time of papermaking, is produced at low cost by recycling resources without causing almost any wear deterioration of papermaking equipment such as wire wear and printing equipment contamination, and is excellent. The paper strength is maintained and there is no paper breakage, and there is no blanket stain due to paper dust, clogging of the sword, color misalignment, etc. Moreover, the paper according to the present embodiment is excellent in various characteristics during printing, particularly color printing, and can be suitably used for high-speed offset color printing such as about 1 to 170,000 copies / hour.

  Next, although the paper of this invention is demonstrated still in detail based on the following Examples, this invention is not limited only to these Examples.

Production Examples 1 to 22 and Comparative Production Examples 1 to 4 (Production of regenerated particles)
As shown in Tables 1 and 2, as a raw material, deinking floss (deinking floss obtained from a used paper processing process for producing used paper pulp, Production Examples 1 to 22) or paper sludge (mainly discharged from the papermaking process) Using dewatered / dehydrated sludge and comparative production examples 1 to 4), a dehydration step, a drying step and a firing step were performed under the conditions shown in Tables 1 and 2, and wet pulverization was performed to obtain regenerated particles.

  Furthermore, in Production Examples 15 to 17, after adding regenerated particles to a sodium silicate solution (water glass) and dispersing to prepare a slurry, the liquid temperature is kept at about 85 ° C. while heating and stirring, and dilute sulfuric acid is added. Thus, a silica sol was produced. Next, the pH of the reaction solution was adjusted to 8 to 11, and silica was precipitated on the surface of the regenerated particles to obtain silica-coated regenerated particles.

  About the obtained reproduction | regeneration particle | grains and a silica covering reproduction | regeneration particle | grain, content of calcium, silicon, and aluminum was calculated | required in oxide conversion, respectively, and the total content rate of calcium, silicon, and aluminum was computed. The results are shown in Tables 3-4. The average particle diameter is also shown in Tables 3-4. In addition, wire wear, productivity, quality stability and appearance were also examined. These results are also shown in Tables 3 to 4.

  In addition, the various measured values shown to Tables 1-4 were measured with the following method.

(A) Average particle diameter of dried product after drying process (firing process inlet) X-ray microanalyzer (model number: EMAX2770, Hitachi, Ltd./Horiba, Ltd.) at an acceleration voltage of 15 kV, black and white polaroid film Twenty X-ray images of the X-ray microanalyzer display were taken and measured at Polaroid (8.5 cm × 10.8 cm).

(A) Ratio of particles having a particle size of 355 to 2000 μm after the drying step (calcination step inlet) The mass ratio of dry matter particles having a particle size of more than 2000 μm is obtained with a 42 mesh sieve. The mass ratio was measured assuming a mass ratio of dried particles having a particle diameter of less than 355 μm.

(C) Content of calcium, silicon and aluminum in regenerated particles (as oxide)
Elemental analysis was performed with an X-ray microanalyzer (model number: E-MAX · S-2150, Hitachi, Ltd./Horiba, Ltd.).

(D) Average particle diameter of regenerated particles 10 mg of a regenerated particle sample was added to 8 mL of a methanol solution and dispersed with an ultrasonic disperser (output: 80 W) for 3 minutes. This solution was measured with a Coulter counter particle size distribution measuring apparatus (TA-II type, manufactured by COULTER ELECTRONICS) using an aperture of 50 μm. However, for a 50 μm aperture that cannot be measured, a 200 μm aperture was used. Moreover, ISOTON II (trade name, manufactured by COULTER ELECTRONICS, 0.7% high-purity NaCl aqueous solution) was used as the electrolytic solution.

(E) Degree of wire wear Using a wear degree test apparatus (manufactured by Nippon Filcon Co., Ltd.), the degree of wear of the plastic wire was measured for 3 hours at a slurry concentration of 2% by mass.

(F) Productivity Each of the raw material dewatering efficiency, productivity, and power required for pulverization was evaluated in five stages, and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: All were highly evaluated and the balance was the best.
○: The evaluation may be averaged.
(Triangle | delta): There existed a problem in either the dehydration efficiency, productivity, and the electric power required for a grinding | pulverization.
X: Actual operation was difficult.

(G) Quality stability The degree of variation was measured for each item of whiteness, particle size, and production volume at a fixed time interval, ranked in ascending order of variation, and evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: Up to the top 10 ○: 11-22nd △: 23-25th ×: 26th or lower

(H) Appearance The color of the regenerated particles was visually observed and divided into white and gray.

  From the results shown in Tables 3 to 4, it can be seen that the regenerated particles of Production Examples 1 to 22 each have a low degree of wire wear and are excellent in productivity and quality stability. On the other hand, it can be seen that the regenerated particles of Comparative Production Examples 1 to 4 have a high degree of wire wear and are inferior in productivity and quality stability.

Examples 1-22 and Comparative Examples 1-7 (Preparation of Newspaper)
Dinking pulp (DIP), pressurized stone ground pulp (PGW), and softwood kraft pulp (NBKP) were blended in the proportions shown in Tables 5-6, and the freeness was 120 mL with a refiner. S. A pulp slurry adjusted to F (based on JIS P 8121) was obtained. To this pulp slurry, 0.5 parts by mass of cationized starch is added per 100 parts by mass of absolutely dry pulp, and the regenerated particles obtained in Production Examples 1 to 22 and Comparative Production Examples 1 to 4 are used as fillers in Table 5. After adding at a ratio shown in -6 and adjusting pH with a sulfuric acid band, newspaper papers having a basis weight shown in Tables 5-6 were made with a twin wire paper machine. Further, 1 g / m ² of oxidized starch was applied on both sides as a surface sizing agent.

  Various physical properties of the obtained newspaper were examined. These results are shown in Tables 5-6. Moreover, commercially available newsprint was prepared as test papers A to C, and various physical properties were examined in the same manner as the newsprints of Examples 1 to 22 and Comparative Examples 1 to 4. The results are shown in Table 6 together as Comparative Examples 5 to 7.

  In addition, the various measured values shown to Tables 5-6 were measured with the following method.

(A) The ratio of each pulp in raw material pulp It measured based on the "fiber composition test method" of JISP8120.

(B) Basis weight It measured based on the "basis weight measuring method" as described in JISP8124.

(C) Density Measured according to “Paper and paperboard—Test method for thickness and density” described in JIS P 8118.

(D) Hot water extraction pH
It was measured according to “Test method for pH of paper, paperboard and pulp-water extract” described in JIS P 8133.

(E) Whiteness The whiteness was measured in accordance with “Hunter whiteness test method for paper and pulp” described in JIS P 8123.

(F) White paper opacity It was measured in accordance with “Paper Opacity Test Method” described in JIS P 8138.

(G) Stiffness (MD direction)
It was measured in accordance with “A stiffness test method using a paper Clark stiffness tester” described in JIS P 8143.

(H) Surface strength After passing a paper sample twice through a calendar made of a metal roll in a laboratory at a linear pressure of 40 kg / cm, the surface of the paper sample was subjected to RI tester (manufactured by Akira Seisakusho). Printing was performed using Ink Tack 6 (manufactured by Toyo Ink Manufacturing Co., Ltd.). The state where the fibers per 10 cm ² were peeled off was visually observed and evaluated based on the following evaluation criteria (grade).
(Evaluation criteria)
1: There is considerable peeling of the fiber 2: There is peeling of the fiber 3: Some peeling of the fiber 4: Little peeling of the fiber 5: Little peeling of the fiber In practice, it is grade 3 at the minimum.

  Next, each characteristic was investigated about the newsprint of Examples 1-22 and Comparative Examples 1-7 based on the following test examples 1-9. The results are shown in Tables 7-8.

Test Example 1 (Still standing)
Using an RI printing suitability tester (manufactured by Akira Seisakusho Co., Ltd.), the newspaper paper surface was repeatedly printed five times with the rubber roll not applied with the test ink. Using a loupe, the surface of the paper web was visually observed in the range of 100 mm × 100 mm, and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Very little standing
○: Little standing.
(Triangle | delta): There is a little bit of standing.
×: There are very many standing spots.

Test example 2 (ink absorption unevenness)
Using an offset color printer (model number: SYSTEM C-20, manufactured by Komori Corporation), four-color printing was performed in the order of indigo, red, yellow, and black at a printing speed of 160,000 copies / hour. The ink density unevenness of the deep blue / red color portion was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Ink density unevenness is not recognized at all, and the image is uniform and clear.
○: Ink density unevenness is hardly recognized, and the image is uniform.
Δ: Ink density unevenness is recognized and the image is slightly non-uniform.
X: Ink density unevenness is obvious and the image is non-uniform.

Test Example 3 (Paper powder accumulation on blanket)
(1) Using the same offset color printer as in Test Example 2, four-color printing was performed in the order of indigo, red, yellow, and black at the same printing speed. After printing 10,000 copies, the degree of paper powder accumulation on the blanket non-image area was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Generation of paper dust is not recognized.
○: Slight generation of paper dust is observed, but there is no practical problem.
Δ: The occurrence of paper dust is clearly recognized.
X: A lot of paper dust is accumulated on the blanket, and the blanket is white.

(2) Using a web offset press (Toshiba web offset press, manufactured by Toshiba Corp.), black monochrome printing was performed at a printing speed of 900 rpm. After printing 60,000 copies, the paper dust deposited on the blanket was scraped off, and the weight was measured and expressed in weight per 100 cm ² . The film thickness of the fountain solution was 0.9 μm.

Test Example 4 (Opacity after printing)
Using the same RI printing suitability testing machine as in Test Example 1, printing was performed while changing the ink amount of black ink. The back surface reflectance after printing with respect to the back surface reflectance before printing (opposite surface of the printing surface) when the reflectance of the printing surface was 9% was determined. A spectral whiteness colorimeter (manufactured by Suga Test Instruments Co., Ltd.) was used for the reflectance measurement.

Test Example 5 (Printed white spot)
The same offset color printing machine as in Test Example 2 was used, and single-color printing of offset rotary printing ink (black) was performed at a dot area ratio of 30 to 100%. About a solid part with a halftone dot area ratio of 100%, the degree of white spots on the printed surface was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Almost no white spots are observed.
○: Little white spots are observed.
Δ: White spots are observed.
X: White spots are remarkable.

Test Example 6 (Nepari property)
Two newspaper paper samples were cut to a suitable size and immersed in water for 10 seconds, and then the two sheets were quickly brought into close contact and passed through a calendar at a linear pressure of 100 kg / cm. After drying at room temperature for 24 hours, the peel strength of the two sheets was measured using a tensile tester (model number: Autograph AGS-500NG, manufactured by Shimadzu Corporation). In addition, the larger the numerical value, the higher the Nepari property (adhesiveness).

Test Example 7 (Ink drying property)
Using the same offset color printing machine as in Test Example 2, four-color printing was performed in the order of indigo, red, yellow, and black with newspaper printing ink having a vegetable oil content of 45% at the same printing speed. Overlap the 500 copies of the printed material so that the printed surface and the white paper surface overlap, and leave it for 1 day under a load of 5 kgf (about 49 N), and then visually observe the degree of dirt on the white paper surface based on the following evaluation criteria: And evaluated.
(Evaluation criteria)
(Double-circle): Dirt is hardly recognized.
○: Only a small amount of dirt is observed.
Δ: Dirt is observed.
X: Dirt is remarkable.

Test Example 8 (Number of paper breaks)
Using an offset rotary press (Toshiba offset rotary press, manufactured by Toshiba Corporation), black monochrome printing was performed at a printing speed of 900 rpm, and the number of occurrences of sheet breakage was measured during 60,000 copies.

Test Example 9 (Back-through)
Using the same web offset press as in Test Example 8, black single color printing was performed at the same printing speed. After printing 60,000 copies, the black solid surface was visually observed from the back side and evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Almost no see-through is observed.
○: Only a small amount of strikethrough is recognized.
(Triangle | delta): See-through is recognized.
X: The showthrough is remarkable.

  From the results shown in Tables 7 to 8, the newsprints of Examples 1 to 22 contain 50% or more of calcium, silicon, and aluminum. Since it is made by adding paper to the raw material pulp containing more than mass%, it is not only obtained at low cost by recycling resources, but also has an appropriate basis weight, density and hot water extraction pH, whiteness, rigidity It has a surface strength and also has excellent opacity and paper strength. Moreover, the newspapers of Examples 1 to 22 have no or little fluffing, ink absorption unevenness, accumulation of paper dust on the blanket and paper breakage, and high opacity after printing. It can be seen that it has characteristics that are very suitable for high-speed offset printing, for example, because there is no or little.

  On the other hand, the newspapers of Comparative Examples 1 to 4 are not deinked floss, but regenerated particles made from paper sludge are used as fillers, and the amount of used paper pulp is small as raw material pulp. Therefore, resource saving and cost reduction are not achieved, and in addition to eruption, ink absorption unevenness, paper powder accumulation on the blanket, and paper breakage, most of opacity after printing, white spots on prints and back-through are bad. As a result, it is understood that the characteristics suitable for high-speed offset printing are not provided.

  In addition, as in Comparative Examples 1 to 4, the commercially available newsprint papers of Comparative Examples 5 to 7 were also used for opacity after printing, printing blank areas, in addition to fluffing, ink absorption unevenness, paper powder accumulation on blankets, and paper breakage. It can be seen that most of the images and the show-through are bad, and the characteristics are not suitable for high-speed offset printing.

The paper of the present invention can be used as, for example, newsprint paper, publishing paper, book paper, and the like particularly suitable for high-speed offset color printing in a satellite type or tower press type offset color printing machine.

That is, the present invention
As a raw material, a paper for the filler and pulp as the main constituent raw material,
Before Kipa Help is composed of 50 to 100% by mass of waste paper pulp,
Paper with at least the above-mentioned filler added internally,
The filler is a regenerated particle agglomerate obtained through a dehydration step, a drying step, a firing step and a pulverization step using deinked floss discharged from a waste paper processing step as a main raw material, and having the following composition:
At least the regenerated particle aggregate is used as a filler for internal addition, and is contained in the paper in an amount of 4 to 35% by weight as a paper ash.
Recycled particle internal paper characterized by
As composition of recycled particle aggregate
The regenerated particle aggregate is
Containing at least calcium, silicon and aluminum in the regenerated particles ,
And the component of the regenerative particles contains calcium, silicon and aluminum in terms of oxides in a mass ratio of 40 to 82: 9 to 30: 9 to 30 by elemental analysis ,
Calcium, total content of silicon and aluminum, is at least 93 mass% in the constituent component of the reproduced particles, Playback particles internally added paper.

Play particles internally added paper of the present invention has a high ash content yield during papermaking, without causing little wear deterioration and printing facilities dirt papermaking equipment wire wear, etc., it is manufactured at low cost by recycling of resources, excellent Paper strength is maintained and there are few paper breaks, blanket stains due to paper dust, printed white spots, etc. are also low, and ink absorbency is excellent, opacity is low and there are few showthroughs. As publishing paper, book paper, etc., it can be suitably used for offset printing such as high-speed offset color printing, particularly high-definition printing in high-speed offset printing.

Play particles internally added paper of the present invention, as described above, as a raw material, a filler and pulp as a main construction material, 該Pa pulp is made 50 to 100 wt% waste paper pulp was internally added at least the filler It is a paper, and the filler is a regenerated particle agglomerate obtained through a dehydration step, a drying step, a firing step and a pulverization step using a deinking floss discharged from a used paper processing step as a main raw material, and having the following composition: At least the regenerated particle aggregate is used as a filler for internal addition, and the paper ash content is contained in paper in an amount of 4 to 35% by mass. calcium at least during playback particles containing silicon and aluminum, and components of the reproduction particles, by elemental analysis, calcium, silicon and aluminum, in terms of oxide 40 to 82: 30: contains at a mass ratio of 9 to 30, calcium, total content of silicon and aluminum, Ru der least 93 mass% in the constituent component of the reproduced particles.

In addition, when the addition rate of the filler containing regenerated particles is too small, the effect of using the filler is not sufficiently expressed, and conversely, when too large, there is a possibility that the paper strength may be reduced. The paper ash content is preferably 4 to 35% by mass, and more preferably 4 to 25% by mass.

Thus, playback particles internally added paper according to the present embodiment, the raw material pulp and waste paper pulp containing more than 50 wt%, the deinking froth discharged from waste paper treatment process as a main raw material, during playback particles It is a regenerated particle aggregate that contains calcium, silicon, and aluminum in a specific mass ratio in terms of oxides, and that the total content of these calcium, silicon, and aluminum is a specific ratio or more in the constituents of the regenerated particles. The additive filler is internally added in a quantity of 4 to 35% by mass as paper ash in paper . Therefore, the reproduction particles internally added paper according to the present embodiment has a high ash content yield during papermaking, without causing little wear deterioration and printing facilities dirt papermaking equipment wire wear, etc., at low cost by recycling the resources Manufactured and maintained excellent paper strength, without paper breaks, no blanket stains due to paper dust, clogging of swords, color misalignment, etc. Moreover playback particles internally added paper according to the present embodiment, when printing, particularly excellent in various characteristics in color printing, can be suitably used for high-speed offset color printing, e.g. 12-170000 parts / about hr .

Production Examples 1 to 20 and Comparative Production Examples 1 to 4 (Production of regenerated particles)
As shown in Tables 1 and 2, as a raw material, deinking floss (deinking floss obtained from a used paper processing process for producing used paper pulp, Production Examples 1 to 20 ) or papermaking sludge (mainly discharged from the papermaking process) Using dewatered / dehydrated sludge and comparative production examples 1 to 4), a dehydration step, a drying step and a firing step were performed under the conditions shown in Tables 1 and 2, and wet pulverization was performed to obtain regenerated particles.

Further, in Production Examples 13 to 15 , after the regenerated particles were added and dispersed in a sodium silicate solution (water glass) to prepare a slurry, the liquid temperature was maintained at about 85 ° C. while heating and stirring, and dilute sulfuric acid was added. Thus, a silica sol was produced. Next, the pH of the reaction solution was adjusted to 8 to 11, and silica was precipitated on the surface of the regenerated particles to obtain silica-coated regenerated particles.

From the results shown in Tables 3 to 4, it can be seen that the regenerated particles of Production Examples 1 to 20 each have a low degree of wire wear and are excellent in productivity and quality stability. On the other hand, it can be seen that the regenerated particles of Comparative Production Examples 1 to 4 have a high degree of wire wear and are inferior in productivity and quality stability.

Examples 1-20 and Comparative Examples 1-7 (Preparation of Newspaper)
Dinking pulp (DIP), pressurized stone ground pulp (PGW), and softwood kraft pulp (NBKP) were blended in the proportions shown in Tables 5-6, and the freeness was 120 mL with a refiner. S. A pulp slurry adjusted to F (based on JIS P 8121) was obtained. To this pulp slurry, 0.5 part by mass of cationized starch is added per 100 parts by mass of absolutely dry pulp, and the regenerated particles obtained in Production Examples 1 to 20 and Comparative Production Examples 1 to 4 are used as fillers in Table 5. After adding at a ratio shown in -6 and adjusting pH with a sulfuric acid band, newspaper papers having a basis weight shown in Tables 5-6 were made with a twin wire paper machine. Further, 1 g / m ² of oxidized starch was applied on both sides as a surface sizing agent.

Various physical properties of the obtained newspaper were examined. These results are shown in Tables 5-6. Moreover, commercial newsprint was prepared as test papers A to C, and various physical properties were examined in the same manner as the newsprints of Examples 1 to 20 and Comparative Examples 1 to 4. The results are shown in Table 6 together as Comparative Examples 5 to 7.

Next, each characteristic was investigated about the newsprint of Examples 1-20 and Comparative Examples 1-7 based on the following test examples 1-9. The results are shown in Tables 7-8.

From the results shown in Tables 7 to 8, the newsprints of Examples 1 to 20 include regenerated particles whose deinking froth is a raw material, each containing calcium, silicon, and aluminum in specific proportions and a total of 93 % by mass or more. As a filler, it is a paper pulp that is internally added to a raw pulp containing 50% by weight or more of recycled paper pulp, so that not only can it be obtained at low cost by recycling resources, but also a moderate basis weight, density and hot water It can be seen that it has extraction pH, whiteness, stiffness, and surface strength, and has both excellent opacity and paper strength. In addition, the newspapers of Examples 1 to 20 have no or little fluffing, ink absorption unevenness, accumulation of paper dust on the blanket and paper breakage, high opacity after printing, and printing whiteout and showthrough. It can be seen that it has characteristics that are very suitable for high-speed offset printing, for example, because there is no or little.

That is, the present invention
As a raw material, a paper having pulp and filler as main constituent raw materials,
The pulp comprises 50-100% by weight of waste paper pulp,
A paper in which at least the filler is internally added to the pulp ;
The filler is obtained through a dehydration process, a drying process, a baking process, and a pulverization process using deinked floss discharged from the waste paper processing process as a main raw material, and without adding a process of agglomerating particles after the pulverization process. Regenerated particle aggregates adjusted to have a composition,
At least the regenerated particle aggregate is used as a filler for internal addition, and the paper ash content is contained in the paper as 4 to 35% by mass ,
Blank paper opacity according to JIS P 8138 is 91-95%,
Hot water extraction pH conforming to JIS P 8133 is Ru der 6.0 to 9.5,
Recycled particle internal paper characterized by
As the composition of the regenerated particle aggregate, the regenerated particle aggregate is:
Containing at least calcium, silicon and aluminum in the regenerated particle aggregate ,
And the component of the regenerated particle aggregate contains calcium, silicon, and aluminum at a mass ratio of 40 to 82: 9 to 30: 9 to 30 in terms of oxide by elemental analysis,
The present invention relates to a regenerated particle-containing paper in which the total content of calcium, silicon and aluminum is 93% by mass or more in the constituents of the regenerated particle aggregate .

As described above, the recycled particle-containing paper according to the present invention includes, as raw materials, pulp and filler as main constituent raw materials, and the pulp is composed of 50 to 100% by weight of waste paper pulp, and at least the filler is contained in the pulp . A step of agglomerating particles after the pulverization step , wherein the filler is obtained through a dehydration step, a drying step, a firing step and a pulverization step using deinking floss discharged from the waste paper processing step as a main raw material. It is a regenerated particle aggregate adjusted to have the following composition without addition , and at least the regenerated particle aggregate is used as a filler for internal addition, and is contained in the paper in an amount of 4 to 35% by mass as paper ash , JIS blank opacity conforming to P 8138 is 91% and 95%, hot water extraction pH conforming to JIS P 8133 are characterized by a 6.0 to 9.5 der Rukoto, the composition of the reproduction particle aggregate The regenerated particle aggregate contains at least calcium, silicon and aluminum in the regenerated particle aggregate , and the component of the regenerated particle aggregate is converted to oxide by converting elemental analysis into calcium, silicon and aluminum. The total content of calcium, silicon, and aluminum is 93% by mass or more in the constituents of the regenerated particle aggregate .

The constituents of the regenerated particle aggregate thus obtained contain calcium, silicon and aluminum. The ratio of these calcium, silicon, and aluminum in the constituents of the regenerated particle aggregate is determined with an X-ray microanalyzer (model number: E-MAX S-2150, Hitachi, Ltd./Horiba, Ltd.). Analysis is performed, and calcium: silicon: aluminum is 40 to 82: 9 to 30: 9 to 30 in terms of oxides , and a mass ratio of 60 to 82: 9 to 20: 9 to 20 is particularly preferable. . In particular, when the regenerated particle aggregate is a silica-coated regenerated particle aggregate , the ratio of calcium, silicon, and aluminum is 30 to 62:29 to 55: 9 of calcium: silicon: aluminum in terms of oxide. It is preferable that it is -35. At the same time, these calcium, total content ratio of the oxide equivalent in the elemental analysis of the silicon and aluminum is 9 3 mass% or more.

Moreover, in order to adjust the total content of calcium, silicon and aluminum to 93 % by mass or more in terms of oxides, for example, means for using a flocculant containing no iron in the agglomeration treatment of drainage sludge, and manufacturing equipment processes other than iron Designed or lined with other materials to prevent iron from being mixed into the system due to wear, etc., and further adopt a means to remove iron by installing high magnetic materials such as magnets in the drying and classification equipment Is possible. In particular, iron is preferably a causative substance that lowers the whiteness by oxidation, and thus is preferably removed selectively.

Thus playback particles internally added paper obtained is according to JIS P 8133 - hot water extraction pH, as measured in accordance with "paper, paperboard and pulp water extract pH test method" is 6.0 or more, 9. It is preferably 5 or less, more preferably 6.1 or more and 9.0 or less. When the hot water extraction pH is in such a range, the elution of calcium carbonate present in the regenerated particle aggregate is prevented, the shape of the regenerated particles is stabilized, and the formation of calcium hydroxide is prevented. suppressing the occurrence of dirt or scale in the system, it is possible to degradation control and resource recycling in the reproduction particles added paper. Further, to improve ink drying of the reproduced particles internally added paper, or fewer ink absorption irregularities, and sufficiently suppress the deterioration, it is also possible to further improve the fixability of storage stability and aids.

Blank opacity of reproduction particle internally added paper, but strike through at the time of printing are required to have a high opacity terms unlikely to occur, according to JIS P 8138 Taking newsprint Examples "paper not It is 91 to 95% as measured in accordance with “Transparency test method” , and more preferably 92 to 94%.

Claims (5)

A paper mainly composed of raw pulp and filler,
The raw pulp consists of 50-100% by weight of waste paper pulp,
At least as the filler, it is obtained through dehydration process, drying process, firing process and pulverization process using deinked floss as a main raw material, contains calcium, silicon and aluminum, and by elemental analysis, calcium, silicon and Paper made of recycled particles having a total aluminum content of 90% by mass or more.   The paper according to claim 1, wherein the regenerated particles are silica-coated regenerated particles whose surfaces are coated with silica.   The paper of Claim 1 or 2 which contains 4-35 mass% of regenerated particles as a filler with respect to raw material pulp.   The paper according to claim 1, 2 or 3, wherein the hot water extraction pH according to JIS P 8133 is 6.0 to 9.5. Basis weight conforming to JIS P 8124 is a 38~46g / m ^2, paper of claim 1, 2, 3 or 4.