JP5237655B2 - Bulky paper and method for producing bulky paper - Google Patents

Description

  The present invention relates to a bulky paper and a method for producing the same. More specifically, the yield of bulking agents is improved by using resource-recycled recycled particles or recycled particle aggregates that recover, recycle and reuse papermaking inorganic chemicals from waste paper, and are bulky and highly opaque. The present invention relates to a bulky paper such as a printing paper or a newspaper and a method for manufacturing the same.

  Wastewater generated in various pulp manufacturing processes and papermaking processes including the waste paper recycling process contains a significant proportion of inorganic particles such as kaolin, clay, talc, calcium carbonate, white carbon, and titanium. As a method for treating the solid content in these wastewaters, conventionally, the solid content is separated by solid-liquid separation using precipitation or flotation, and this is dewatered to make paper sludge, and further incinerated to reduce the volume. At the same time, the remaining incineration ash was used as a raw material for cement and as a heat insulating material for the furnace, or was landfilled.

  In recent years, the use of waste paper has increased dramatically from the viewpoint of environmental protection and recycling, and COD and SS-causing substances discharged from the waste paper pulp manufacturing process are larger than other paper sludges. It has been proposed to recycle discharged paper sludge.

  In Patent Document 1, a mixture of organic matter and inorganic particles (so-called papermaking sludge) is carbonized under anoxic conditions in which the presence of oxygen-containing gas is limited, and then decarbonized under the presence of oxygen-containing gas. In addition, a filler-added paper characterized by containing 1 to 30% by mass of regenerated particles having a median diameter of 0.5 to 5 μm and having a cationized polymer added thereinto has been introduced. What should be noted in this method is that the cationized polymer is contained in the regenerated particles and added internally to the paper material, thereby further improving the filler yield and the regenerated particle aggregates by aggregating ability due to the crosslinking reaction of the cationized polymer. This suggests that the addition amount can be reduced.

  However, the cationized polymer aggregates not only the regenerated particles but also the ash contained in the recycled paper pulp when blended with raw pulp, especially recycled pulp, and when blended with mechanical pulp, Since it also reacts with the resin content, it tends to cause a decrease in whiteness and variation in the regenerated particle-added paper. As a special issue, the problem is that the density is high and the bulk is difficult to be raised, resulting in a decrease in opacity. In the case of excessive aggregation, for example, it causes printing unevenness.

  Patent Document 1 discloses that very fine regenerated particles produced in the production process of regenerated particles are agglomerated fine regenerated particles and raw pulp using a cationized polymer to improve the yield of regenerated particles and reduce paper strength. The technique which tries to improve is described.

  However, this method is a so-called “floc” agglomerate that is cross-linked and adsorbed with a cationized polymer flocculant, and can be easily made into fine particles by physical force such as a feed pump or a stirring device. Therefore, it is difficult to ensure stable, desired opacity and paper strength maintenance.

  On the other hand, Patent Document 2 uses only bleached kraft pulp as a raw material pulp, uses spindle-aggregated light calcium carbonate as a filler, and contains an AKD internal additive sizing agent and a polyhydric alcohol ester of a saturated fatty acid. A paper stock containing a bulking agent or a bleached kraft pulp as a raw material pulp, a spindle aggregation type light calcium carbonate as a filler, an AKD or ASA internal sizing agent, and a saturated fatty acid Low substitution with a substitution degree of 0.4 to 0.7 is applied to a base paper obtained by making a paper containing a bulking agent containing polyamidoamine as a component under conditions of a paper making speed of 500 m / min or more and a press linear pressure of 60 kgf / cm or less. Applying and drying carboxymethylcellulose with a degree of ash content of 20% or more yields printing paper with low density, high opacity, and internal strength. It has been described.

  However, it is a resource wasting type using calcium carbonate, a natural resource, and it is inferior in bulkiness because sufficient yield of bulking agent cannot be obtained, and high carboxymethylcellulose is coated on the paper surface and dried, so there is much equipment damage The invention lacks operational stability.

  Moreover, as the invention of Patent Document 2 is referred to, the conventional bulky paper is prepared by blending a surfactant called a bulking agent into the raw material pulp, bonding the fiber surface and the hydrophilic group of the surfactant, In this method, the surface is covered with a hydrophobic group of a surfactant and the bond between fibers due to hydrogen bonding is weakened to increase the bulk. Generally, there are two types of bulking agents, nonionic and cationic. In neutral papermaking, the cationic bulking agent has a high affinity with anionic pulp and forms a denser floc, Since the paper has a high density, there is a problem that the bulkiness effect is lowered. On the other hand, since the nonionic bulking agent is ionic neutral, it is difficult to adsorb to anionic pulp and filler, and the yield is poor.

Further, the bulking agent is mainly an organic acid or an ester compound thereof, an alcohol compound, an animal or vegetable compound derived from fat or sugar, and easily rots within the paper machine and easily causes defects. For this reason, it is necessary to improve the yield of the bulking agent as much as possible to minimize the retention inside the paper machine.However, in the conventional example, the yield of the bulking agent is low and the bulkiness effect is difficult to obtain, and the decay inside the paper machine・ There is a problem that defects are likely to occur.
Japanese Patent Laid-Open No. 2003-119692 JP 2006-265753 A

  SUMMARY OF THE INVENTION The main problem to be solved by the present invention is to provide a bulky paper that is bulky, has few foreign matter defects, and has high opacity, and has no surface penetration, and has a high surface strength, and a method for producing the same.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
A bulky paper in which a filler, a flocculant and a bulking agent are internally added to pulp,
As the filler, paper sludge mainly made from deinked floss discharged from the waste paper treatment process is obtained through dehydration, drying, firing and pulverization processes, and aggregated in the firing process, and calcium and silicon are contained in the particles. And cationic regenerated particles containing three components of aluminum are used ,
The flocculant is anionic,
The bulking agent is nonionic having a cationic group and an anionic group.
Bulky paper characterized by that.

[Invention of Claim 2]
The anionic flocculant has a charge density of −0.3 to −6.0 meq / g.
The bulky paper according to claim 1.

[Invention of Claim 3]
The bulking agent has an addition amount of 0.2 to 1.5% in terms of the absolute dry mass ratio to pulp.
The bulky paper according to claim 2.

[Invention of Claim 4 ]
The bulky paper according to any one of claims 1 to 3 , wherein the bulking agent contains a fatty acid ester as a main component.

[Invention of Claim 5]
An organic polymer coagulant is used as a coagulant,
Bulky paper given in any 1 paragraph of Claims 1-4.
[Invention of Claim 6]
A method for producing a bulky paper by internally adding a filler , a flocculant and a bulking agent to pulp,
Paper sludge mainly made from deinked floss discharged from the waste paper treatment process is obtained through dehydration, drying, firing and pulverization processes, and is agglomerated in the firing process to obtain calcium, silicon and aluminum 3 in the particles. Cationic regenerated particles containing ingredients are used as the filler,
Papermaking in the presence of an anionic flocculant having a charge density of -0.3 to -6.0 meq / g and a nonionic bulking agent having a cationic group and an anionic group ;
A method for producing a bulky paper.
[Invention of Claim 7]
Adding a coagulant prior to adding the bulking agent to the pulp slurry, and adding the bulking agent prior to adding the filler;
A method for producing a bulky paper according to claim 6.

  According to the present invention, it is a bulky paper having a high bulk strength, having no foreign matter defects, and having a high opacity, and having no surface see-through, and having a strong surface strength.

Next, an embodiment of the present invention will be described.
(Outline of the present invention)
The bulky paper of the present invention uses a white pigment (hereinafter referred to as regenerated particles) obtained by pulverizing incineration ash obtained by incineration of papermaking sludge and deinking floss that have been incinerated or landfilled as industrial waste. It can be produced at low cost by recycling resources, and further, by using regenerated particles, the yield of the bulking agent is improved and a bulky paper is obtained. Further, when the bulking agent and the regenerated particles are made in the presence of an anionic flocculant, further bulkiness can be obtained. The reason is considered as follows.
The bulking agent is a method of increasing the bulk by weakening the bond between fibers due to hydrogen bonding, and in order to improve the bulkiness, a cationic bulking agent having a good yield to an anionic pulp fiber is preferable. In the case of the agent, a dense floc is formed with the pulp fiber, and as a result, the bulk may be lowered. Therefore, as a whole, a non-bulk bulking agent into which not only a cationic group but also an anionic group is introduced is preferably used so that the affinity with the pulp fiber does not become too high. However, the nonionic bulking agent is excellent in bulking effect, but has a low fixability to pulp fibers, and has a problem that it is easily deposited inside the paper machine and becomes a foreign matter defect.

  Furthermore, when a conventional general filler is added to the system in which the bulking agent is not sufficiently fixed to the pulp fiber, the conventional general filler has anionic property, so that only the cationic part of the bulking agent is adsorbed, and the pulp fiber There is a problem that the fixing property of the bulking agent is further reduced and not only the bulkiness is lowered, but also the occurrence of foreign matter defects due to the deposition of the bulking agent inside the paper machine. As conventional fillers, clay and calcium carbonate can be raised, but clay has a plate-like crystal structure, the plane part is anionic, and the thin section is cationic, so the part in contact with the fiber is an anionic part. It is substantially anionic, and calcium carbonate on the other hand is said to have almost no charge on the particle surface.

  In contrast, the regenerated particles of the present invention are in a form in which calcium, silicon and aluminum components are aggregated in an irregular shape, and many cationic parts are exposed on the surface of the filler, so that they appear to be cationic. Since the anionic portion of the bulking agent and the pulp fiber that is also anionic can be adsorbed suitably, the fixing property of the bulking agent to the pulp fiber can be improved. Since these effects can be imparted, these effects are combined to obtain a bulky paper.

  Furthermore, the inventors have found that a bulky paper can be obtained by defining the flocculant added to the raw material in which the pulp slurry, the bulking agent and the regenerated particles are blended. In other words, when a cationic flocculant is added as a flocculant, it is suitably fixed to the pulp fiber, so that when the paper layer is formed, it appears as if the entire paper layer has been agglomerated, and the density increases and the bulk increases. Low paper. However, when an anionic flocculant is added, the anionic pulp fiber and bulking agent do not form a dense floc, and the regenerated particles are adsorbed on the anionic part of the pulp fiber and bulking agent. Therefore, unlike the case where a cationic bulking agent is used, a dense floc is not formed. When the paper layer is formed in such a state, a bulky paper can be obtained as a result.

  As a result of intensive studies on anionic flocculants for forming a bulkier paper, the charge density is −0.3 to −6.0 meq / g, preferably −0.5 to −5. When a flocculant such as polyacrylamide or colloidal silica in the range of 0 meq / g, particularly colloidal silica is used, it is bulky without forming dense flocs with respect to a system composed of pulp fiber, bulking agent and regenerated particles. It has been found that the yield of the agent becomes good and shows high bulkiness. More specifically, when the charge density is less than −0.3, separation from the pulp fiber is not obtained, and the bulkiness is poor. On the other hand, when the charge density exceeds −6.0 meq / g, the bulking agent In addition, there is a problem that unnecessary aggregation of the regenerated particles and a problem that the fixing of the pulp fiber or the bulking agent and the regenerated particles is excessively decreased to cause a decrease in bulkiness or a foreign matter defect due to a decrease in the yield of the bulking agent.

  Since the yield of the regenerated particles is improved in proportion to the yield of the bulking agent, the opacity derived from the regenerated particles is easily imparted to the paper, and a paper with higher opacity can be obtained. In addition, when the regenerated particles are adsorbed to the pulp fiber or bulking agent, it is difficult for the regenerated particles to fall off from the paper surface. The effect which can be prevented is also acquired.

  As the coagulant, for example, organic polymer coagulants such as polyacrylamide, polyethyleneimine, and methacrylic acid, especially methacrylic acid has high affinity with the above-mentioned cationic regenerated particles and bulking agents, and anionic aggregation Combined with the yield action of the agent, the yield of the regenerated particles and the bulking agent can be improved, and a bulky paper that is even bulkier and less likely to cause defects due to the bulking agent not yielding is preferable.

(Specific embodiments of the present invention)
Next, an embodiment of the present invention will be described by taking a coated paper as an example.
〔pulp〕
The type of pulp used in the present embodiment (hereinafter also referred to as “raw pulp”) is not particularly limited. For example, chemical pulp, mechanical pulp, waste paper pulp, or other pulp can be used. One or more of them can be appropriately selected and used.

  As the chemical pulp, for example, unbleached softwood pulp (NUKP), unbleached hardwood pulp (LUKP), bleached softwood pulp (NBKP), bleached hardwood pulp (LBKP) and the like can be used as the raw material pulp.

  Examples of the mechanical pulp include stone grand pulp (SGP), pressurized stone grand pulp (PGW), refiner ground pulp (RGP), chemi-ground pulp (CGP), thermo grand pulp (TGP), ground pulp (GP), Thermo mechanical pulp (TMP), Chemi thermo mechanical pulp (CTMP), refiner mechanical pulp (RMP), etc. are mentioned.

  Waste paper pulp includes, for example, disaggregation / deinked waste paper pulp, disaggregation / deinking / bleached waste paper pulp, etc. produced from magazine waste paper, flyer waste paper, office waste paper, Kami white waste paper, etc., from the viewpoint of environmental protection, It is preferable to blend a large amount of these waste paper pulps.

  In addition, rag pulp, straw pulp, esparto pulp, bagasse pulp, bamboo pulp, kenaf pulp, and other auxiliary pulps such as bast pulp, etc. made from cotton, flax, hemp, jute, manila hemp, ramie, etc. are used. You may do it.

[Formulation process]
In the preparation process, various chemicals such as bulking agents are added to the pulp, processed to a predetermined quality, and sent to a paper machine.

<Freeness>
The freeness of the pulp is preferably 280 cc to 360 cc, more preferably 300 cc to 340 cc. If it is less than 280 cc, beating progresses too much and the fine fibers increase, and the yield of fine fibers deteriorates. Even if it exceeds 360 cc, the drainage is fast and the fine fibers are difficult to yield, and the inside of the paper machine is soiled and pitched. Trouble occurs easily.

<Regenerated particles>
a) Recycled particles derived from paper sludge Recycled particles derived from paper sludge (white pigment obtained by pulverizing incinerated ash obtained by incineration of paper sludge), for example, those described in JP-A-2002-167523 can do. Specifically, for example, paper sludge is extruded into a string shape having a diameter of 3 to 10 mm, cut to a length of 8 to 10 cm, and then incinerated at 500 to 1000 ° C. with a rotary kiln. A white pigment having an average particle size of 0.1 to 10 μm obtained by pulverization in the order of dry pulverization and wet pulverization can be used. As the quality of the regenerated particles derived from papermaking sludge, for example, the whiteness (powder whiteness meter (manufactured by Kett Scientific Laboratory, type C-100)) is 60% or more, and the hardness (plastic wire wear degree) (Nippon Filcon, 3 hours)) of less than 100 mg can be used.

b) Regenerated particles derived from deinking floss Regenerated particles derived from deinking floss (obtained by going through dehydration, drying, firing and pulverization processes of papermaking sludge mainly made from deinking floss discharged from the used paper processing process, As the regenerated particles that are aggregated in the firing step and contain three components of calcium, silicon, and aluminum in the particles, for example, those described in JP-A-2007-99613 and JP-A-2007-100262 are used. can do. Specifically, for example, a flocculant is added to deinked floss having a moisture content of about 95 to 98% by mass, dehydrated to about 50 to 60% by mass, and the dehydrated product is dried with hot air and classified, and then 450 to 650 ° C. In such a range, it is fired and agglomerated so that the unburned ratio becomes 10 mass% or more and less than 15 mass%. White particles obtained by pulverizing the calcined inorganic particle aggregate so that the primary particles have an average particle diameter of 0.01 to 0.1 μm and the secondary particles in which the primary particles have aggregated have an average particle diameter of 0.1 to 10 μm. Pigments can be used. As the quality of the regenerated particles derived from the deinking floss, for example, the oil absorption is 30 to 100 ml / 100 g. Moreover, the peak height of the average particle diameter in the differential curve of the particle size distribution by the Coulter counter method is adjusted to 30% or more, and furthermore, calcium, silica and aluminum in the raw material sludge are converted into oxides in an amount of 30 to 82: 9 to By adjusting the mass ratio to 35: 9 to 35, the pore volume of the inorganic particle aggregate is 0.15 to 0.60 cc / g, the pore surface area is 10 to 25 m ² / g, and the pore radius is 300 to White pigments adjusted to 1000 angstroms can also be used.

  In this embodiment, recycled particles (recycled particles derived from paper sludge and regenerated particles derived from deinking floss) are both foreign matter inside the paper machine due to the yield in the raw pulp and the flow of recycled particles into white water. The average particle size is preferably 0.1 μm or more, more preferably 0.3 μm or more from the viewpoint of prevention of conversion, and the average particle size is 10 μm or less from the viewpoint of maintaining printability and preventing clogging of the blade tip. Is preferably 8 μm or less.

  In terms of filler quality, regenerated particles derived from deinking floss are preferred over regenerated particles derived from papermaking sludge. In addition to deinking floss, papermaking sludge contains sludge and heavy foreign matter that have been processed from papermaking wastewater, so firing unevenness is likely to occur, and it cannot be uniformly fired. Increase in objects and decrease in opacity are likely to occur.

  The bulky paper of this embodiment uses the above regenerated particles as at least an internal filler. The recycled particles can be recycled by baking paper sludge or deinked floss, so there is no need to dispose of landfills as waste, reducing environmental impact and saving resources. It contributes greatly. Further, since the raw material is papermaking sludge or deinking floss generated in the used paper processing step, there is an advantage that it is inexpensive, the amount of new natural inorganic mineral used can be suppressed, and the manufacturing cost is sufficiently reduced.

c) Silica-coated regenerated particles Further, as the suitable regenerated particles internally added to the raw material pulp in this embodiment, silica-coated regenerated particles in which the surface of the regenerated particles is coated with silica can be particularly preferably used.

As silica-coated regenerated particles, for example, those described in JP-A-2007-146354 and JP-A-2007-186800 can be used. Specifically, for example, after deinking floss dehydrated to a moisture content of 95 to 98% is further dehydrated to 40% to 70%, the moisture content becomes 2 to 20 mass% with hot air at 100 to 200 ° C. To dry. The dried product is adjusted so that the particle size of 355 to 2000 μm is 70% by mass or more. The dried product is baked and agglomerated in the range of 510 to 750 ° C., and after adjusting the unburned matter, it is finely pulverized, the primary particles have an average particle diameter of 0.01 to 0.1 μm, and the primary particles are agglomerated secondary. The particles are adjusted so as to have an average particle diameter of 0.1 to 10 μm to obtain regenerated particle aggregates. In this regenerated particle aggregate, the peak height of the average particle diameter in the differential curve of the particle size distribution by the Coulter counter method is adjusted to 30% or more, and furthermore, calcium, silicon and aluminum in the deinking floss are converted into oxides. By adjusting to a mass ratio of 30 to 82: 9 to 35: 9 to 35, the pore volume of the inorganic particle aggregate is 0.15 to 0.60 cc / g, the pore surface area is 10 to 25 m ² / g, A white pigment having a pore radius adjusted to 300 to 1000 angstroms is preferred. This regenerated particle aggregate is added to and dispersed in an aqueous alkali silicate solution, and a slurry is prepared. Then, while heating and stirring, a diluted solution of mineral acid such as sulfuric acid, hydrochloric acid, nitric acid is added at a liquid temperature of 70 to 100 ° C. to produce a silica sol. By adjusting the pH of the final reaction solution to a range of 8.0 to 11.0, a white pigment obtained by generating silica sol particles having a particle diameter of 10 to 20 nm on the surface of the regenerated particle aggregate can be used. This silica-coated regenerated particles improve the oil absorption and opacity due to the silica precipitation effect by making calcium, silicon and aluminum into a mass ratio of 30 to 62:29 to 55: 9 to 35 in terms of oxides. Can do. As the quality of the silica-coated regenerated particles, for example, the oil absorption is 30 to 100 ml / 100 g, and when used as an internal additive in the paper making process, a white pigment having an average particle diameter adjusted to 0.1 to 10 μm is used. You can also.

  The silica-coated regenerated particles are preferably adjusted with a known pulverizer such as a wet pulverizer to adjust the average particle diameter to 0.1 to 10 μm, and the ratio of the particle diameter of 0.1 to 10 μm is at least 80% or more and 20 μm. More preferably, the above ratio is 0.5% or less. If the average particle diameter is less than 0.1 μm, the fixability to paper is poor, the yield is poor, and foreign matter is easily formed inside the paper machine, which is not preferable.

  The silica-coated regenerated particles can be reacted with sodium hydroxide in the used paper processing step for recycle use to contribute to the recycle use of the raw material for papermaking and regenerated particles as a buffering agent or bleaching aid. In addition, when such silica-coated regenerated particles are internally added to the raw material pulp as a filler, the paper whiteness, opacity, surface strength, and ink drying properties are further increased than when regenerated particles not coated with silica are used. In addition, the effects of ink absorption unevenness and bulkiness can be further improved.

<Fillers other than regenerated particles>
In addition to the above regenerated particles and silica-coated regenerated particles, one or more fillers generally used for papermaking can be used in combination as long as the effects of the present invention are not impaired. For example, heavy calcium carbonate, light calcium carbonate, titanium oxide, talc, silica, clay, colloidal hydrous silica (commonly called white carbon), inorganic fillers such as aluminum hydroxide, synthetic polymer fine particles such as polystyrene resin and urea formaldehyde resin A known filler such as can be used. There are no particular restrictions on the shape of these inorganic fillers, and various types such as granular, tension, spindle, plate, and amorphous can be used. Regarding the particle size, gloss, paper flexibility, paper surface, etc. Therefore, generally, talc is preferably 15 μm or less, and calcium carbonate is preferably 3 μm or less.

<Bulky agent>
The bulking agent used in this embodiment is not particularly limited, but a nonionic bulking agent is preferred to a cationic bulking agent. When a cationic bulking agent is used, it is easily combined with the anionic nature of the pulp fiber, so that it is likely to form a dense floc, and the bulkiness tends to be lowered. The use of a nonionic bulking agent is preferable because a bulky paper can be formed together with the bulking effect of the regenerated particles having a cationic property. Nonionic bulking agents include oil-based nonionic surfactants, sugar alcohol-based nonionic surfactants, sugar-based nonionic surfactants, polyhydric alcohol-type nonionic surfactants, higher alcohols, and polyhydric alcohols. Fatty acid ester compound, higher alcohol or polyoxyalkylene adduct of higher fatty acid, polyoxyalkylene adduct of higher fatty acid ester, polyoxyalkylene adduct of polyhydric alcohol and fatty acid ester compound, fatty acid polyamidoamine, etc. The bulking agent used in (1) can be used. Among these, those containing a fatty acid ester are particularly preferable because the yield effect by the coagulant and the flocculant described later is high and the bulkiness effect is high.

  In this embodiment, the addition amount of the bulking agent is not particularly limited, but is generally 0.2 to 1.5%, preferably 0.3 to 1.2%, more preferably 0.5 in terms of the absolute dry mass ratio to pulp. -1.0%. In this embodiment, recycled particles are used as the internal filler, and paper making is preferably performed in the presence of an anionic flocculant, so that a bulky effect can be obtained as described above. Therefore, the problem in the conventional form that sufficient bulkiness cannot be obtained even if the addition amount is increased only by adding the bulking agent is solved. Therefore, the addition amount of the bulking agent itself can be suppressed, and it is sufficient that the addition amount of the bulking agent is 0.2% or more. In this regard, when a general filler is used instead of regenerated particles, the bulking agent is difficult to adsorb to the pulp fiber as described above, and a dense floc is also formed as described above even in a form not using an anionic flocculant. Form and inferior in bulkiness. However, in this embodiment, since an anionic flocculant, particularly an anionic flocculant having a charge density of −0.3 to −6.0 meq / g, is used, it is possible to prevent the yield from being reduced. The minimum addition amount is 0.2%. Thus, in this embodiment, since the yield reduction of the bulking agent is prevented, the addition amount of the bulking agent is sufficient to be 1.5% or less. Even if the addition amount of the bulking agent exceeds 1.5%, the bulkiness is hardly improved, and conversely, an increase in cost, corruption in the paper machine, an increase in foreign matter defects, and the like are caused.

<Order of bulking agent addition>
In the present invention, the bulking agent is preferably added after the coagulant described later and before the filler and the flocculant. In particular, it is preferable to add a coagulant, a bulking agent, a filler, and a flocculant in this order.

  The bulking agent is preferably added after the coagulant. When the bulking agent is added before the coagulant, the anionic trash is adsorbed on the cationic group of the bulking agent, the effect of the bulking agent adsorbing to the pulp fiber is reduced, and the bulking effect cannot be obtained. Since the yield to the pulp decreases, the bulking agent accumulates inside the paper machine and causes dirt and defects, which is not preferable. In particular, fatty acid-based bulking agents having a high bulking effect are nonionic and have both cationic and anionic properties. Therefore, when anionic trash is combined with the cationicity of the bulking agent, the bulking agent becomes an anion as a whole. This is not preferable because adsorption to the pulp is inhibited. Conversely, when a bulking agent is added to the pulp fiber after adding the coagulant, the anion trash is adsorbed to the pulp fiber, so the yield of the bulking agent due to anion trash does not decrease, and the adsorptivity to the pulp is high. preferable.

  The bulking agent is preferably added before the regenerated particles. Since the regenerated particles are cationic, when they come into contact with the pulp fiber before the bulking agent, the anionic property of the pulp fiber surface is electrically neutralized by the cationic property of the regenerated particle aggregate, and the anionic property of the pulp fiber is reduced. descend. In this state, when a bulking agent, particularly a nonionic bulking agent, is added, the bulkiness agent having low ionicity is more difficult to be adsorbed to the pulp fiber, the yield of the bulking agent becomes worse, and a paper having a desired bulkiness is obtained. Not only is this not possible, but a bulking agent accumulates inside the paper machine and foreign matter defects occur, which is not preferable. Conversely, when regenerated particles are added after adding the bulking agent, the anionicity of the pulp fiber and the cationic group of the bulking agent are preferably easily combined, and the regenerated particles are sufficiently small compared to the bulking agent, The anionic property of the pulp fiber having affinity with the bulking agent can be adsorbed to the pulp fiber without being inhibited by the bulking agent, and both the bulking effect by the bulking agent and the bulking effect by the regenerated particles can be obtained. In other words, the nonionic bulking agent has a problem that the affinity for the pulp is low and the yield is poor, but by adding cationic regenerated particles, the anionicity of the pulp fiber and the anionicity of the bulking agent are improved. Further, since the regenerated particles can be combined to improve the yield of the bulking agent, the yield can be further improved and the bulkiness can be improved.

  In addition, due to the above effect, the yield of the regenerated particles can be improved, and the effect of improving the opacity derived from the regenerated particles can be imparted to the paper. As a result, for example, during printing, regenerated particles are taken up by the printing ink, and it is possible to suppress a white spot trouble. Therefore, a bulky paper having a higher surface strength and suitable for printing can be obtained.

  It is preferable to add a coagulant after adding a coagulant, a bulking agent, and a filler. This is because it is necessary to make the molecular weight larger than any of the above-mentioned coagulant, bulking agent, and filler because it is added for the purpose of forming a large floc so that it can be effectively drained by the wire of the paper machine. is there. If a flocculant is added before the coagulant, bulking agent, and filler, the adsorption of these chemicals to pulp fibers is not preferable because of the large molecular structure. However, in the present invention, for the same reason that the regenerated particles are added after the addition of the bulking agent, even if colloidal silica having a small molecular weight is used as the flocculant, the bulking agent molecules and the regenerated particles are not affected. Thus, it was found that colloidal silica can be favorably adsorbed to the pulp fiber, and it is easy to form agglomerated flocs, resulting in a bulky paper that is bulky and has high opacity and surface strength.

  The interval between the additions of the respective chemicals is not particularly limited, but the interval between the coagulant and the bulking agent is preferably 1 to 15 minutes, and the interval between the bulking agent and the regenerated particles is preferably 1 to 10 minutes. The interval is preferably 1 to 5 minutes.

  By adding this series of papermaking methods, that is, a coagulant, a bulking agent, regenerated particles, and colloidal silica in this order, both the bulking effect by improving the yield of the bulking agent and further the bulking effect by regenerated particles are sufficiently obtained. As a result, it has been found that a bulky paper having particularly high opacity and surface strength can be obtained.

<Coagulant>
In this embodiment, a coagulant can be added to effectively adsorb the filler and fine fibers to the pulp fibers. Examples of the coagulant include polyacrylamide (PAM), polyvinylamine (PVAm), polydiallyldimethylammonium chloride (Polydadomac, PDADMAC), polyamine (PAm), polyethyleneimine (PEI), polyethylene oxide (PEO), methacrylic acid. Examples include organic polymer coagulants such as acids, and inorganic coagulants such as sulfuric acid bands and polyaluminum chloride. Among these, methacrylic acid is preferable because it has a high affinity with the cationic regenerating filler and the bulking agent, and can improve the yield of the regenerated particles and the bulking agent in combination with the retention action of the flocculant described later.

<Flocculant>
In this embodiment, it is preferable to add an anionic flocculant after the addition of a coagulant in the pulp preparation stage and further in the pre-stage of the papermaking process following the pulp preparation stage. As the component of the anionic flocculant, either a polymer flocculant or an inorganic flocculant that has been conventionally used as a yield improver can be used. Examples of the polymer flocculant include organic polymer flocculants such as polyacrylamide (PAM), polyvinylamine (PVAm), polyamine (PAm), and polyethylene oxide (PEO). Among these, it is preferable to use at least one of PAM and PAm. Examples of the inorganic flocculant include bentonite and colloidal silica. In particular, by using anion PAM or colloidal silica, particularly colloidal silica, which has a high yield effect of regenerated particles and bulking agent, a bulky effect can be obtained effectively.

  The charge density of the flocculant is -0.3 to -6.0 meq / g, preferably -0.5 to -5.0 meq / g, more preferably -1.0 to -3.0 meq / g. desirable. If the charge density is less than −0.3 meq / g, the aggregation effect may not be sufficiently exhibited, the yield of fine fibers is reduced, and the area ratio of impurities is increased. On the other hand, if it is larger than -6.0 meq / g, the floc becomes large and the formation is destroyed, so that the surface strength and the printability are lowered, which is not preferable.

  In the case of an organic polymer flocculant, the shape of the polymer may be any of linear, network, dendrogram, or micelle. The average molecular weight of the flocculant is preferably 5 million to 20 million, more preferably 11 million to 17 million. When the average molecular weight of the anionic flocculant is less than 5 million, the effect of the flocculant is not sufficiently exhibited, and the yield of fine fibers may be reduced. It is not preferable because it becomes large and destroys the formation.

  The addition amount of the flocculant is preferably 50 ppm to 500 ppm, more preferably 300 ppm to 500 ppm as a pure component with respect to the pulp. If the addition amount is less than 50 ppm, the predetermined agglomeration effect is not sufficiently exhibited, and the yield of the bulking agent may be reduced. On the other hand, if it exceeds 500 ppm, the floc becomes large and the formation is destroyed, which is not preferable.

<Other chemicals>
In this embodiment, in addition to the above regenerated particles, bulking agent, coagulant, and flocculant, an internal sizing agent, a fixing agent, a yield improver, a cationizing agent, a paper strength enhancer, and an antifoaming agent are added as necessary. Various paper making aids such as colorants and dyes may be added.

[Bulky paper (coated paper)]
The coated paper obtained as described above preferably has an ash content of 3 to 20% in accordance with JIS P 8251 and a density in accordance with JIS P 8118 of 0.80 g / cm ³ or more. When the ash content is less than 3%, sufficient opacity cannot be obtained, and when the ash content exceeds 20%, the density increases and the paper strength decreases. The coated paper of this embodiment has a density of 0.80 to 1.00 g / cm ³ , preferably 0.86 to 0.94 g / cm ³ , more preferably 0.88 to 0.92 g / cm ³ . It is desirable to adjust so that it becomes. When the density is less than 0.8 g / cm ³ , a decrease in opacity and hand feeling are impaired, resulting in a problem that printing workability and printing appearance are lowered.

Moreover, although the generation | occurrence | production of the foreign material defect by addition of a bulking agent cannot be prevented completely by this invention, generation | occurrence | production of a defect can be suppressed. Defects can be evaluated by the foreign matter area ratio, and the foreign matter area ratio required for the printing paper, newsprint, etc. of the present invention is preferably 0.30 mm ² / m ² or less, more preferably 0. .24mm and a ² / m ² or less, more preferably 0.18 mm ² / m ² or less. If the foreign matter area ratio exceeds 0.30 mm ² / m ² , not only is the sharpness of the image area inferior, but the printed characters may not be discriminated, which is not preferable.

  Similarly, since the regenerated particles can be fixed to the anionic group of the bulking agent and the yield can be improved, the effect of improving the opacity derived from the regenerated particles can be imparted to the bulky paper. For this reason, the opacity can be set to 90 or more, more preferably 92 or more, and particularly 94 or more. Therefore, it is preferable that the print back-through hardly occurs and a vivid printed matter is obtained. On the other hand, if the opacity is less than 90, it is not preferable because the image line portion may show through and the printability of the printed matter is poor.

[Paper making process]
The papermaking equipment that can be used in this embodiment is not particularly limited, but in order to improve the yield of fine fibers, a wire part made of a gap former, a press part made of a straight-through type without an open draw, and a dryer made of a single deck dryer. It is preferable to combine the parts.

[Wire part (head box)]
The adjusted pulp slurry is sent to the wire part via the head box. The wire part is not particularly limited, such as a long-form former, a combination of a long-form former and an on-top former, or a twin wire former, but the paper jet ejected from the head box is immediately sandwiched between two wires. A gap-type gap former is preferable because there is little difference between the front and back because it dehydrates from both sides, the nip pressure required for dehydration can be reduced in the press part described later, and a bulky paper is obtained.

[Press part]
The paper layer in the wire part is transferred to the press part and further dewatered. The press machine can be either a straight-through type, an invar type, or a reverse type, and a combination of these can also be used, but the straight-through type with no open draw is easy to hold the paper, This is preferable because there are few operational troubles such as paper breaks. As a dehydration method, a conventional method such as a suction roll method or a grooved press method can be used. However, if a shoe press having a high dehydration property is used, the linear pressure applied to the paper can be reduced and the bulk is increased. This is preferable because paper is obtained.

[Pre-dryer part]
The wet paper that has passed through the press part is transferred to a single-deck pre-dryer part and dried. The pre-dryer part is preferably a no-open draw type single-deck dryer that has few paper breaks and can be dried efficiently without reducing the bulk. A drying method using a double deck method is also possible, but it is not preferable because it is inferior to a single deck method in terms of operability such as canvas marks, paper breaks, wrinkles, and paper splicing.

[Undercoating]
For the purpose of improving the rigidity, a water-soluble polymer can be coated on the above base paper using a roll coater. Examples of water-soluble polymers include starches such as oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch and raw starch or derivatives thereof, synthetic polymers such as polyacrylamide and polyvinyl alcohol, and water resistance and surface strength improvement. The paper strength enhancing agent described above, the externally added sizing agent for the purpose of imparting sizing properties, or those commonly used as surface treatment agents can be used alone or in combination. Of these, oxidized starch is preferable because it can improve the workability while minimizing the decrease in whiteness while improving the rigidity.

Coating amount in the case of using the oxidized starch as a water-soluble polymer is not particularly limited, preferably 0.1~1.5g per side / m ^2, more preferably 0.2~1.3g / m ^2, most preferably from 0.3 to 1.0 g / m ^2. If it is less than 0.1 g / m ² , the coverage is poor and the effect of improving the stiffness of the base paper is small. If it exceeds 1.5 g / m ² , the stiffness will improve, but the original color of starch will tend to appear on the coated paper, and not only will the whiteness decrease, but the coating liquid will increase and the coating will start from the roll surface. Since the liquid is scattered, coating mist is generated, and defects and foreign matters are easily generated, and workability is deteriorated.

  Such a water-soluble polymer is applied to, for example, a two-roll size press coater, a gate roll coater, a blade metering size press coater, a rod metering size press coater, or a film transfer type roll coater such as a shim sizer or a JF sizer. Can be applied by machine tool. A film transfer type roll coater is preferable because it has a high surface coverage and can prevent a decrease in printability due to dropping of fine fibers. Coating machines other than those described above, such as blade coaters and air knife coaters, are unfavorable because the coatability is poor at low coating amounts and non-coated parts are likely to occur, and uniform coating is required for spray coaters and curtain coaters. Is not obtained, and it is difficult to prevent the fine fibers from falling off.

[Flatening treatment (pre-calendar)]
The base paper after the undercoating is preferably subjected to a flattening process using a precalender before the topcoating (pigment coating). As the pre-calender, a soft calender having a metal roll on the upper side and an elastic roll on the lower side is preferable because of its high surface improvement. The pre-calendar can be performed in one stage or a combination of two or more stages as required. By the pre-calender treatment, the surface of the base paper after the application of the water-soluble polymer is flattened, and the subsequent calender does not require excessive flattening treatment, thereby reducing the strength of the paper without reducing the strength of the paper. Flatness can be improved, and sufficient printability and paper strength as a coated paper can be obtained. Further, by performing the flattening treatment on the surface of the base paper, it is possible to improve the coating property of the top coating, to suppress the generation of mist, and to suppress the coating unevenness of the coating liquid. The linear pressure of the pre-calender is preferably 10 to 80 KN / m, more preferably 10 to 50 KN / m. If it is less than 10 KN / m, flattening of the base paper after application of the water-soluble polymer will not proceed, and if it exceeds 80 KN / m, the base paper will be compressed more than necessary, so the paper strength and bulkiness will decrease. It is not preferable.

[Top coating (pigment coating)]
Next, a coating layer containing a pigment and an adhesive is applied to one or both sides of the base paper to provide a coating layer. Conventional pigments can be used, such as kaolin, fine kaolin, calcium carbonate, talc, satin white, calcium sulfite, gypsum, barium sulfate, white carbon, calcined kaolin, structured kaolin, diatomaceous earth, magnesium carbonate, Inorganic pigments such as titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, zinc oxide, magnesium oxide, bentonite, sericite, polystyrene resin fine particles, urea formalin resin fine particles, fine hollow particles, porous One or more of organic pigments such as fine particles may be appropriately selected and blended. Among them, calcium carbonate having a large whiteness improving effect and clay having a high white paper gloss improving effect are preferable.

  There are no particular limitations on the type of adhesive that is blended in the coating solution together with the above pigments, for example, proteins such as casein and soybean protein; styrene-butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, Conjugated diene latex such as styrene-methyl methacrylate-butadiene copolymer latex, acrylic latex such as acrylic acid ester and / or methacrylic acid ester polymer latex or copolymer latex, ethylene-vinyl acetate polymer latex, etc. Vinyl-based latex, or latexes such as alkali partially soluble or insoluble latex obtained by modifying these various copolymer latexes with a functional group-containing monomer such as a carboxyl group; polyvinyl alcohol, olefin-maleic anhydride resin , Me Synthetic resin adhesives such as min resin, urea resin, urethane resin; starches such as oxidized starch, positive starch, esterified starch, dextrin; cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, etc. Adhesives used can be mentioned, and one or two or more of these can be appropriately selected and used.

  Although there is no limitation in particular in the ratio of the pigment in a coating agent, and an adhesive agent, Preferably an adhesive agent is 3-17 mass parts by solid content ratio with respect to 100 mass parts of pigments, More preferably, it is 5-15. Part by mass. If the amount of the adhesive is less than 3 parts by mass, the strength of the coating layer is lowered, and the coating layer is easily taken up by the printing ink at the time of printing, so that it is easy to cause troubles that are not printed (white spots). . On the other hand, if it exceeds 17 parts by mass, the effect of improving the surface strength reaches its peak and the economic efficiency deteriorates.

  Furthermore, for example, various commonly used auxiliaries such as a fluorescent brightening agent, a fluorescent brightening agent fixing agent, an antifoaming agent, a release agent, a coloring agent, and a water retention agent are appropriately blended in the coating liquid. You can also

  The coating of the top coat layer (pigment coating layer) on the base paper is preferably performed, for example, in a coater part between dryer parts which is performed in a plurality of stages, usually two stages of a pre-dryer part and an after-dryer part. . In this coater part, as in the case of undercoat coating, for example, a film transfer type roll such as a 2-roll size press coater, a gate roll coater, a blade metering size press coater, a rod metering size press coater, or a shim sizer or JF sizer. It can apply | coat with coating machines, such as a coater. The film transfer type roll coater is preferable because it has a high surface coverage even at a low coating amount and a coated paper having a high surface strength can be easily obtained. Coating machines other than the above, such as blade coaters and air knife coaters, are not preferred because they cannot be applied at low coating amounts, and spray coaters and curtain coaters can be applied at low coating amounts but are uniform. Since a coated surface cannot be obtained, surface coverage and surface strength tend to be low, which is not preferable.

  In addition, when using an on-machine coater that is integrated with the paper machine, the coating device can produce products in a shorter time than an off-machine coater, so that moisture unevenness in the width direction and flow direction can be reduced. It is preferable because more uniform coating can be achieved and uniform surface strength can be obtained. In addition, as a drying method in the dryer part, for example, various heating drying methods such as hot air heating, gas heater heating, and infrared heater heating can be appropriately employed.

The coating amount of the coating liquid into the base paper is per side, preferably ^{3g / m 2 ~10g / m 2} , more preferably ^{5g / m 2 ~9g / m 2} . If the amount of the coating liquid is less than 3 g / m ² per side, an uncoated part is likely to occur on the paper surface, and a part having a low surface strength may be generated. If the coating exceeds 10 g / m ² per side, cracks are likely to occur in the coating layer, and not only the printability but also the cosmetic properties of the coated paper itself are not preferred.

[Calendar part]
For the purpose of imparting glossiness, flatness, and printability to the coating layer, a pair of rolls, at least one of which is a hot roll, preferably a paper is passed between an elastic roll and a metal roll to perform a flattening treatment. it can. The linear pressure of the calendar is preferably 100 to 600 KN / m, and more preferably 100 to 400 KN / m. If it is less than 100 KN / m, the pigment coating layer will not be flattened, and if it exceeds 600 KN / m, the base paper will be compressed more than necessary, and the paper strength and bulkiness will be reduced, which is not preferable. 100-300 degreeC is preferable and the temperature of a metal roll has more preferable 100-200 degreeC. If the temperature is less than 100 ° C, the pigment coating layer does not flatten. If the temperature exceeds 300 ° C, fiber burns may occur or the coated paper itself may turn yellow due to heat and pressure. Is not preferable.

  As the calendar facility, a flattening facility such as a super calendar or a soft calendar can be used. Among them, a multi-nip calender, more desirably a 6-, 8-, or 10-stage multi-nip calender is optimal because it easily adjusts the nip pressure, easily adjusts the stiffness and white paper gloss, and is excellent in bulkiness. Moreover, as an installation place of a calendar, an on-machine type integrated with a paper machine and a coating machine is preferable. In the on-machine type, flattening can be performed immediately after coating with a high paper surface temperature, so it is easy to improve the glossiness of the blank paper, and the linear pressure required to obtain the desired coated paper is low. This is preferable because of a small decrease in property.

  Next, the bulky paper of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  First, as a raw material pulp, LBKP and NBKP are mixed at a ratio (mass ratio) of 80:20, and each 100 parts by mass (absolutely dry amount) of the pulp is a cationized starch (product number: amylofax). T-2600, manufactured by Abebe Japan Co., Ltd.) 1% by mass, and as shown in Table 1, bulking agent, filler (2% by mass), coagulant (0.1% by mass), flocculant (0.1% by mass) Was added to obtain a pulp slurry. The types of fillers, bulking agents, coagulants, and flocculants are as follows.

・ Filler <Recycled particles>
a) Regenerated particles derived from paper sludge (regenerated particles)
It manufactured by adjusting the particle size by the manufacturing method of Unexamined-Japanese-Patent No. 2002-167523, Test Example 8. Specifically, paper sludge obtained by dehydrating to 55-65% with a DIP floater floss or dewatering equipment is cut into a string of 4.5 mm in diameter and 8-10 cm in length, and then incinerated. Regenerated particles having a secondary particle diameter of 3 μm were produced by incineration at 1000 ° C. in a furnace.

b) Regenerated particles derived from deinked floss (regenerated particle aggregates)
It manufactured by adjusting the particle size by the manufacturing method of Unexamined-Japanese-Patent No. 2007-146354 and Example 3. FIG. Specifically, the deinking floss discharged from the waste paper treatment process is dehydrated to a moisture content of 60% (dehydration process), dried at 120 ° C. (drying process), and the moisture content at the firing process inlet becomes 3%. In the first firing step, the unburned portion is 7% so that the unburned portion is 12% by weight (baking step), and the particle size is 500 μm. Grinding (grinding step) produced regenerated particle aggregates.

<Silica-coated regenerated particles (silica composite)>
It manufactured by adjusting the particle size by the manufacturing method of Unexamined-Japanese-Patent No. 2007-146354 and Example 15. Specifically, deinked floss discharged from the waste paper processing process is dehydrated to a moisture content of 50% (dehydration process), dried at 130 ° C. (drying process), and the moisture content at the firing process inlet becomes 3%. In the first firing step, the unburned portion is 7% so that the unburned portion is 12% by weight (baking step), and the particle size is 500 μm. By pulverizing (pulverizing step), a silica-coated regenerated particle aggregate in which silica was deposited on the surface of the regenerated particle aggregate was produced.

<Light calcium carbonate>
Product number: TP121-6S, a light calcium carbonate manufactured by Okutama Kogyo Co., Ltd. was used.

<Clay>
Product No .: TSK-30, filler clay manufactured by Sabae City Riko Co., Ltd. was used.

・ Bulking agent <Nonionic bulking agent>
A fatty acid ester (product number: KB210, manufactured by Kao Corporation) or a polyhydric alcohol (prototype, manufactured by Kao Corporation) was used.

<Cationic bulking agent>
A cationic special surfactant (product number: BAL-1001, manufactured by Nisshin Chemical Laboratory) was used.

-Coagulant Methacrylic acid (product number: Hymo Lock NR-783, manufactured by Hymo Co., Ltd.) or polyethyleneimine (product number: Catiofast SF, manufactured by BASF) was used.

-Flocculant Colloidal silica (product number: NP442, manufactured by Eka Chemicals Co., Ltd.), anion PAM (product number: FA-230, manufactured by Hymo Co., Ltd.), or cationic PAM (product number: DR-8500, manufactured by Hymo Co., Ltd.) used.

Next, after a paper web was manufactured through a wire part, a press part, and a pre-dryer part, a starch coating solution was applied on both sides with a coating amount of 0.5 g / m ² per side. After this undercoating, the film was dried by an after dryer part and flattened by a pre-calender part at a linear pressure of 100 kN / m. Next, in the coater part, 30 parts by mass of fine kaolin clay (product number: AMAZON, manufactured by Kadam) as a pigment, 70 parts by mass of wet heavy calcium carbonate (product number: ESCALON # 90, manufactured by Sankyo Flour Milling Co., Ltd.), adhesive As a coating liquid containing 10 parts by mass of styrene-butadiene latex (Part No .: PA5036, manufactured by Nippon A & L Co., Ltd.), both sides of the base paper were coated so that the coating amount was 8.0 g / m ² . . Next, the base paper with the coating layer formed on both sides was used in an after dryer part to dry the coating layer, and the calendar part was subjected to planarization treatment at a linear pressure of 150 kN / m and a temperature of 200 ° C. Then, it was used for the reel part and the winder part to obtain coated paper.

  Paper was made using a gap former for the wire part, a straight-through type without an open draw for the press part, and a single deck dryer for the dryer part. In the coater part, after undercoating with a film transfer type roll coater, it was flattened with a pre-calender and overcoated with a blade coater. In the calendar part, a flattening process was performed using a multi-nip calendar.

The weight of the coated paper obtained was 105 g / m ^{2 as} measured according to JIS P 8124. The coated paper was evaluated as follows. The results are shown in Table 1.

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

(B) Opacity Measured according to JIS P 8149 “Paper and paperboard—Opacity test method (backing of paper) —diffuse illumination method”.

(C) Contaminant area ratio Contaminant measuring device (manufactured by ESK Create Co., Ltd., scanner: EPSON ES-2000, optical resolution: 1600 DPI, cutoff: 0.001 mm ² , measurement area: A4 size, threshold setting range: black and white 256 levels, threshold value: 75% from the black part among 256 levels).

(D) Printability Using an offset printing machine (model number: Lithopia L-BT3-1100, manufactured by Mitsubishi Heavy Industries, Ltd.), color 4 (color: product number: ADVAN, manufactured by Dainippon Ink & Chemicals, Inc.) 5000 copies of color printing were performed. About this printing surface, the printing nonuniformity of the printed matter was observed visually and with a magnifying glass (10 times), and the degree thereof was evaluated based on the following evaluation criteria.
○: There is no show-through, excellent printability, and practical use.
Δ: Some show-through occurs and printability is slightly inferior, but it can be used in practice.
X: Back-through occurs, printability is poor, and actual use is impossible.

(E) Surface strength With respect to the printed surface, the occurrence of a tray on the paper surface (a trouble that a part of the paper surface is taken up by a blanket of a printing press and printing is lost) visually and with a magnifying glass (10 times). The degree was evaluated based on the following evaluation criteria.
○: No omission, excellent printability, and practical use.
Δ: Some omission occurs and printability is somewhat inferior, but it can be used in practice.
X: Omission occurs, the printability is inferior, and actual use is impossible.

  Since each of the coated papers of the examples contains regenerated particles and a bulking agent, the coated paper has low density and high bulkiness, high opacity, low contamination area ratio, and excellent printability and surface strength. It is craft paper.

  On the other hand, since the coated paper of the comparative example does not use the predetermined regenerated particles and bulking agent as in the examples, the density (bulk), opacity, area ratio of impurities, printability, surface strength Either of these is bad coated paper.

  The present invention is a printing paper, a newspaper paper, etc., in which a bulking agent is also added to a recycled paper internal paper of resource circulation type that recovers, recycles, and reuses a filler that is a main component of recycled particles from waste paper. It can be applied as a bulky paper and its manufacturing method.

Claims (7)

A bulky paper in which a filler, a flocculant and a bulking agent are internally added to pulp,
As the filler, paper sludge mainly made from deinked floss discharged from the waste paper treatment process is obtained through dehydration, drying, firing and pulverization processes, and aggregated in the firing process, and calcium and silicon are contained in the particles. And cationic regenerated particles containing three components of aluminum are used ,
The flocculant is anionic,
The bulking agent is nonionic having a cationic group and an anionic group.
Bulky paper characterized by that. The anionic flocculant has a charge density of −0.3 to −6.0 meq / g.
The bulky paper according to claim 1. The bulking agent has an addition amount of 0.2 to 1.5% in terms of the absolute dry mass ratio to pulp.
The bulky paper according to claim 2. The bulky paper according to any one of claims 1 to 3 , wherein the bulking agent contains a fatty acid ester as a main component. An organic polymer coagulant is used as a coagulant,
Bulky paper given in any 1 paragraph of Claims 1-4. A method for producing a bulky paper by internally adding a filler , a flocculant and a bulking agent to pulp,
Paper sludge mainly made from deinked floss discharged from the waste paper treatment process is obtained through dehydration, drying, firing and pulverization processes, and is agglomerated in the firing process to obtain calcium, silicon and aluminum 3 in the particles. Cationic regenerated particles containing ingredients are used as the filler,
Papermaking in the presence of an anionic flocculant having a charge density of -0.3 to -6.0 meq / g and a nonionic bulking agent having a cationic group and an anionic group ;
A method for producing a bulky paper. Adding a coagulant prior to adding the bulking agent to the pulp slurry, and adding the bulking agent prior to adding the filler;
A method for producing a bulky paper according to claim 6.