JP5483902B2 - Book paper and manufacturing method thereof - Google Patents

Description

The present invention relates to book paper, and more specifically, waste paper pulp and inorganic particles in waste paper pulp from the viewpoint of global environmental protection and effective use of resources, and pulp fibers separated from pulp fibers in the deinking process of waste paper processing equipment The present invention relates to a bulky book paper containing deinked floss as a main raw material and containing regenerated particles obtained through dehydration, drying, combustion and pulverization steps as a main paper, and a method for producing the same .

  Book paper used for comics and the like is required to have a thick paper thickness (low density) and a high whiteness with respect to US tsubo. Therefore, conventionally, it has become the design which mix | blended many bulky mechanical pulp with 60-100%. However, since mechanical pulp has lower whiteness than chemical pulp such as LBKP, whiteness is 50 to 65%, which is lower than that of coated paper or high-quality paper. It is possible to increase the whiteness by bleaching mechanical pulp, but there is a problem that the bulk is reduced by bleaching. In order to compensate for this whiteness, it is common to add an inorganic compound such as calcium carbonate. However, adding a large amount of an inorganic compound makes it difficult to produce bulk, lowers the surface strength, and causes paper peeling during printing. Since it occurs, there is a limit to the amount.

  Therefore, conventionally, the deinking floss separated from the pulp fiber is used as the main raw material in the deinking process of the used paper processing equipment, and this main raw material is filled with the regenerated particles obtained through the steps of dehydration, drying, combustion and pulverization. The book paper which mix | blended as is proposed by patent document 1 and patent document 2. FIG.

  Further, Patent Document 3 proposes a printing paper obtained by papermaking a hardwood pulp and / or paper stock containing a bulking agent for paper produced by chemical treatment and calendaring.

JP 2008-156774 A JP 2007-146351 A JP 2006-225774 A

  However, in the conventional method for producing a regenerated particle aggregate proposed in Patent Document 1 or Patent Document 2, the regenerated particle raw material turns yellow due to a high combustion temperature around 600 ° C., and the whiteness of the regenerated particle aggregate is low. Therefore, in order to increase the whiteness, it is necessary to increase the blending amount. As a result, there is a problem that the ash content in the paper is increased and the bulk is hardly generated.

  Further, according to Patent Document 3, the interfiber bonding force is reduced by adding a bulking agent, and thereby the surface strength is lowered, so that paper peeling may occur at the time of printing, which causes a problem in practice. .

Therefore, a main object is accordingly an object of the present invention is to produce a particularly suitable regeneration particles book paper, by containing the reproduction particles based paper book paper, and vice whiteness provide high bulky book paper It is to provide a manufacturing method .

The above object of the present invention consists of a base paper having LBKP as a main raw material and a mechanical pulp blending ratio measured in accordance with JIS P8120 (1998) of 30 to 50%, with a filler internally added, at least Provided is a book paper in which a water-soluble resin is applied to the surface of a base paper, the book paper including at least regenerated particles obtained by the following manufacturing steps (a) to (e) as the filler. Is achieved.
(B) Deinking floss separated from pulp fibers in the deinking process of the used paper processing equipment for producing used paper pulp is used as the main raw material, and (b) the main raw material is dehydrated to a moisture content of 40 to 90% in the dehydrating process. , (c) the dehydrated the main raw material is dried and burned at least first and second temperature of 300 ° C. to 500 ° C. in the first combustion furnace of a combustion process consisting of two stages, (d) the combustion and main raw material after it was again burned in the second combustion furnace, reproduction particles and pulverized by (e) pulverizing step.

Further , the above object of the present invention is that the regenerated particles have a whiteness of 75 to 85%, an ash content measured in accordance with JIS P8251 (2003) of 5 to 20% by mass, and a density of 0.00. It is effectively achieved by providing a book paper that is 4 to 0.7 g / cm ³ and has a whiteness of 70 to 80% in accordance with JIS P8148 (2001) .

Furthermore, the above-mentioned object of the present invention is to use LBKP as a main raw material, blend mechanical pulp so that the blending ratio of mechanical pulp measured in accordance with JIS P8120 (1998) is 30 to 50%, and contain filler. A book paper manufacturing method comprising a base paper to which a water-soluble resin is applied at least on the surface of the base paper, wherein regenerated particles contained at least as the filler are produced by the following manufacturing steps (a) to (e): This is achieved by providing a book paper manufacturing method characterized in that it is manufactured . (B) Deinking floss separated from pulp fibers in the deinking process of the used paper processing equipment for producing used paper pulp is used as the main raw material, and (b) the main raw material is dehydrated to a moisture content of 40 to 90% in the dehydrating process. (C) drying and burning the dehydrated main raw material at a temperature of 300 ° C. to 500 ° C. in a first combustion furnace of a combustion process consisting of at least first and second stages; and (d) the burned main raw material. After burning again in the second combustion furnace,
(E) Regenerated particles are obtained by pulverization in the pulverization step.

  As a result of extensive research, the present inventor used deinking floss separated from pulp fibers as the main raw material in the deinking process of the used paper processing equipment for producing used paper pulp, and this main raw material was dehydrated, dried, burned and burned. In the production process of regenerated particles that obtain regenerated particles through each step of pulverization, the combustion step recombusts the first combustion step comprising the first combustion furnace and the deinking floss burned in the first combustion furnace. And having a second combustion process comprising a second combustion furnace, and in the first combustion furnace, an in-furnace temperature of 300 ° C. to 500 ° C., which is extremely low compared to the conventional case. It has been found that the low temperature regenerated particles having the characteristics required as a filler for particularly high white and bulky book paper can be stably produced by performing the combustion treatment in the above, and the present invention has been conceived. Is a thing

  According to the present invention, recycled particles particularly suitable for book paper are manufactured, and the recycled particles are contained in the base paper of the book paper, so that a book paper with high whiteness and bulk can be obtained.

It is a manufacturing equipment flow figure of regenerated particles concerning one embodiment of the present invention. It is explanatory drawing of a 2nd combustion furnace (external heat kiln furnace), (a) is a partial cross section front view which shows an internal structure, (b) is the expanded view of the inside.

  Hereinafter, an embodiment of the book paper of the present invention in which recycled particles are internally added as a filler to a base paper will be described in detail. In addition, this invention is not necessarily limited to the following embodiment, In the range which does not deviate from a claim, it cannot be overemphasized that the structure can be changed variously.

  Here, the book paper in the present invention refers to a book paper in which a pigment coating layer is not provided on the base paper surface, that is, a book paper in which a water-soluble resin containing no pigment is applied or impregnated on the base paper surface.

  First, the positioning of the method for producing regenerated particles in the present invention will be described, and then the method for producing regenerated particles and book paper containing the regenerated particles will be described.

  In the deinking process of the used paper processing facility for producing the used paper pulp, the recycled particles in the present invention are mainly made of deinked floss separated from the pulp fiber, and are subjected to a dehydration process, a drying process, at least a first combustion process, and a first combustion process. After the combustion process is performed at 300 ° C. to 500 ° C. in the first combustion furnace (internal heat kiln furnace) in the first combustion process, the second combustion furnace (external heat kiln furnace) in the second combustion process Thus, the main raw material burned in the first combustion furnace is obtained again through a two-stage combustion process and a pulverization process.

  More specifically, hot air of 500 ° C. to 650 ° C. is blown so that the oxygen concentration in the first combustion furnace becomes 0.2% to 20%, combustion treatment is performed at 300 ° C. to 500 ° C., and In the 2-combustion furnace, the combustion product from the first combustion furnace is subjected to combustion treatment at a temperature of 550 ° C to 780 ° C.

  By the way, in the deinking process for producing waste paper pulp, the deinking floss separated from the pulp fiber contains inorganic fine particles as a raw material of the regenerated particles to be obtained by the present invention, and is difficult to use as waste paper pulp. Latex, which is an organic polymer frequently used in fine fibers and coated paper, contains a lot of ink components applied by printing, and in the combustion process, the deinking floss itself generates a combustion reaction (oxidation) and burns itself. There was a problem that heat generation more than the heat treatment with hot air caused excessive combustion of the raw material.

  Such excessive combustion causes yellowing of the raw material due to high-temperature combustion, leading to a decrease in whiteness, melting of the raw material tends to generate hard materials such as gehlenite, increasing the degree of wire wear in the papermaking equipment, In order to form agglomerates due to melting, the pulverization energy is increased in the subsequent pulverization process, the processing efficiency is lowered, the surface of the raw material is exposed to a high temperature, and is melted before the inside of the raw material. There is a problem that (oxidation reaction) does not proceed and organic matter (carbon) remains, resulting in a decrease in whiteness.

  As a means for solving the above problems, the present inventor paid attention to a measure for controlling excessive combustion, and as a result of intensive studies, the deinking floss as a raw material does not self-combust in the first combustion furnace. The combustion temperature of the organic component gas (oxidation) is kept at the furnace temperature of the first combustion furnace that is necessary for releasing the combustion gas (combustible gas) generated by gasification of the organic component contained in the deinking floss. It has been found that promoting only the reaction) can solve the above problems, and has led to the completion of the present invention.

  The present inventor secures an oxygen concentration of 0.2% to 20% necessary for burning combustion gas (combustible gas) in the first combustion furnace, and prevents excessive combustion of the deinking floss. In addition to supplying hot air, it has been found that measures to increase the moisture content of the deinking floss as a raw material are effective. It has also been found that securing an oxygen concentration of 0.2% to 20% in the first combustion furnace results in an in-furnace environment in which combustion is promoted, so that excessive combustion of the deinking floss is likely to occur. Has been.

  Therefore, the present inventor preferably dehydrated the deinked froth used as a raw material in a high water content state of preferably 40% to 90%, more preferably 40% to 70%, and most preferably 45% to 70%. It has been found that feeding into the first combustion furnace is suitable for preventing excessive combustion of the deinking floss. The reason is that by supplying the first combustion furnace with a high water content state, the temperature in the furnace decreases due to the evaporation of water in the first combustion furnace, the self-combustion of the deinking floss is suppressed, and the generated combustion gas ( This is because it is considered that combustion of only the combustible gas) can be promoted, and an excessive increase in the combustion temperature can be suppressed.

  On the other hand, more preferably, a spiral lifter and / or a parallel lifter parallel to the axial center is disposed on the inner wall of the second combustion furnace from one end side to the other end side thereof, so that the raw material can be evenly distributed. Combustion and uniform quality.

  According to the knowledge of the inventor described above, in the first combustion furnace, the raw material deinking floss is exposed to the combustion reaction at a low combustion temperature, and after obtaining a homogeneous first combustion furnace outlet raw material, the remaining whiteness is lowered. It is necessary to combust as much as possible the carbon component that causes the generation of raw materials, so it is necessary to combust the raw materials slowly, and in order to carry out as uniform combustion as possible continuously, the raw material conveyance in the second combustion furnace It has also been found that a method of appropriately controlling the speed is considered to be the most suitable, and as a means for that, it is possible to use a lifter facility to adjust the feed speed of the raw material. However, since a known lifter is generally manufactured from an iron material, iron is contained in the raw material as a contaminant, which causes a problem of reducing whiteness due to oxidation of iron. Therefore, the present inventor has found a technique that can produce high-quality regenerated particles such as no iron oxidation problem and no reduction in whiteness by providing a stainless steel lifter in the second combustion furnace. It was.

  As the structure of the second combustion furnace, either an external heat kiln or an internal heat kiln can be adopted as appropriate. In the external heat kiln, since the direct fire of the burner is not directly exposed to the raw material, overheating can be prevented and uniform firing quality (high whiteness) can be obtained. On the other hand, the internal heat kiln has an advantage that the refractory attached inside has heat insulation and at the same time emits far infrared rays and can be heated with a small amount of heat. The structure of the second combustion furnace can be appropriately selected in view of these conditions, but it is optimal to provide a lifter for any of the methods.

  On the other hand, conventionally, a deinking sludge is used as a raw material sludge, and a drying process for drying the sludge, and the dried deinking sludge is supplied into the furnace from the upper part of the cyclone type combustion furnace and burned while being swung down. A primary combustion process for obtaining a primary combustion product containing fuel, and a primary combustion product that communicates with the cyclone-type combustion furnace and receives unburned content from the lower end of the primary combustion product. A method for producing a white pigment or white filler from deinking sludge is known, which includes a secondary combustion step of burning until a predetermined whiteness is achieved using the combustion heat of the primary combustion step while promoting contact It is. According to this method, regenerated particles similar to those obtained by the present invention can be obtained.

  However, in this method, a cyclone type fluidized combustion furnace is used, a raw material and air of several tens to several hundreds of microns are supplied from the supply port as a swirling flow, and the raw material is effectively mixed with air by the swirling action of air. In order to burn, the fine particles contained in the raw material are discharged out of the system together with the exhaust gas, the product yield is reduced, and the burning time (heating time) of the deinking floss that is the main raw material is short, so that the unburned portion is reduced. It has been found that there are problems such as being easily generated, and the quality (particularly shape) of the finally obtained combustion product is not constant and the brightness of the combustion product varies.

  Therefore, as a result of repeated studies on means for obtaining regenerated particles with stable quality without causing excessive combustion, the present invention, as described above, includes the first combustion process and the first combustion process as the first combustion process. It has at least two stages of a second combustion process having a second combustion furnace that again burns the deinked floss burned in the combustion furnace, and in the first combustion process, combustion treatment is performed at 300 ° C. to 500 ° C. By doing so, it has been found that regenerated particles with stable quality can be produced.

  In a more preferred embodiment, the raw material after dehydration is dried and burned in series, and the combustion time (residence time) in the first combustion furnace by internal heat is preferably 30 minutes to 90 minutes, more preferably 40 minutes to Using a first combustion furnace of 80 minutes, most preferably 50 minutes to 70 minutes, and drying the raw material after dehydration by a preferred internal heat (direct heating) kiln furnace in which the main body is placed horizontally and rotates around the central axis The combustion time (residence time) for performing combustion and then recombusting the combustion product obtained from the first combustion furnace is preferably 60 minutes to 240 minutes, more preferably 90 minutes to 150 minutes, and most preferably 120 minutes to A preferred external heat (indirect heating) kiln furnace using a second combustion furnace with external heat of 150 minutes and rotating around the central axis in a horizontal position, particularly an external heat electric furnace that can easily adjust the combustion temperature, Also adopt the method of burning It is.

  In the embodiment described later with reference to the drawings, an internal heat kiln furnace is selected as the first combustion furnace, and an external heat kiln furnace is selected as the second combustion furnace, and a known combustion furnace is used as these kiln furnaces. it can. Moreover, it is not limited to a kiln furnace, A well-known apparatus, such as a fluidized bed furnace, a stalker furnace, a cyclone furnace, a semi-dry distillation / negative pressure combustion type furnace, can also be used.

  In a preferred aspect of the present invention, the first combustion furnace is performed with internal heat, and the subsequent second combustion furnace is performed with external heat. Furthermore, as this external heat second combustion furnace, a known combustion furnace such as an indirect heating type combustion furnace using heavy oil or the like as a heat source may be employed.

  According to the internal heat kiln furnace that can be suitably used as the first combustion furnace, drying and combustion can be performed in one furnace, and drying and combustion can be performed slowly and stably from the supply port to the discharge port. It progresses and pulverization of combustion products is suppressed. In addition, when combusted in an external heat kiln furnace that can be suitably used as the second combustion furnace, the combustible can be discharged from the end of the combustible with a predetermined residence time from the discharge port of the other end and further combusted by external heat. Since uniform heat is applied to the gas, the combustion becomes uniform and does not cause variations in combustion. Furthermore, the combustion product is gently agitated by friction caused by the rotation of the inner wall of the kiln furnace, so that it is difficult to produce fine powder. As a result, the quality and shape of the final combustion product become stable.

  In the conventional first combustion furnace, the moisture content is 40% in order to efficiently burn fine fibers in the raw material, latex that is an organic polymer frequently used for coated paper, ink components applied by printing, and the like. While the method of dehydrating and drying to less than that and combusting at a high temperature is also described in the publicly-known literature described above, the present inventor By heating at a low temperature compared to the temperature, the organic matter contained in the raw material is converted into combustion gas, and the combustion gas is combusted (oxidized), stabilizing the quality of the resulting regenerated particles, white It has been found that the contribution to the improvement of the degree is great.

  As described above, uniform and stable low-temperature regenerated particles can be obtained by performing the drying and combustion processes in an internal heat kiln furnace and an external heat kiln furnace in at least two stages of combustion furnaces.

  The internal heat or external heat kiln furnace used as a suitable combustion furnace can lift and stir the combusted material without slipping by making the internal refractory into a hexagonal or octagonal shape instead of a circumferential shape. In reality, the kiln furnace is cylindrical, and it is optimal to provide a lifter for stirring the combusted material in terms of uniform combustion of the raw material and uniform quality. This is considered to be related to the fact that the present invention intends to burn the entire raw material carefully at a low temperature in the first combustion furnace.

  Here, selection of the combustion furnace which the inventor has focused most on obtaining suitable regenerated particles will be described.

  Conventionally used combustion furnaces can be broadly classified into four types: stalker furnaces (fixed bed), fluidized bed furnaces, cyclone furnaces, and kiln furnaces. As a result of repeated studies on manufacturing, the following matters became clear.

  For the stalker furnace (fixed bed), it is difficult to adjust the degree of combustion of the deinking floss, and the combustion products are not uniform, and combustion of the deinked floss with a high ash content causes dust to fall from the clearance between the grate. Not suitable. Since air is blown up and burned under the combustion material through the grate, calcium carbonate or the like becomes fly ash and is sent to the exhaust gas facility together with the exhaust gas.

  Since the fluidized bed furnace uses a particulate fluid medium such as silica sand as the fluid medium in the furnace, there is a problem that the silica sand is mixed into the regenerated filler and the quality is deteriorated. That is, uniform stirring cannot be performed. After the cinnabar sand is mixed in a fluidized bed and combusted, the cinnabar sand and the burned material are separated, and the cinnabar sand is returned to the combustion furnace, and only the burned material is taken out. Since combustion is performed in a floating state with dredged sand, it is difficult to adjust the degree of combustion, resulting in variations in quality. Since the combustion furnace is burned while passing through the stoker (stepped shape) of the combustion furnace with a predetermined width, the ash is not sufficiently stirred and the combustion varies in the width direction. In addition, the combusted material is pulverized by friction and collision with high hardness silica sand, and the fly ash is discharged out of the system to reduce the yield.

  As for the cyclone furnace, the fixed carbon in the combustion product cannot be burned sufficiently because it passes through the furnace in an instant, leading to a decrease in whiteness.Furthermore, fine particles are not separated by the cyclone and treated with the exhaust gas. Yield decreases because it goes to the process.

  As a result of intensive investigations on the above problems, the combustion furnace is selected as the most suitable combustion means to be burned in the kiln furnace, and the first combustion which is the optimum embodiment in the present invention. It has been found that the furnace is an internal heat kiln and the subsequent second combustion furnace is an external heat kiln for the following reasons.

  In other words, the external heat kiln furnace has a configuration in which heating equipment is provided outside the kiln furnace, so the structure of the kiln furnace is complicated, and a large amount of heat source is required because the combustion products are dried and burned indirectly. Therefore, when the external heat kiln furnace is used as the first combustion furnace for the drying and combustion treatment of the raw material having a high water content after dehydration according to the present invention, the drying / combustion efficiency is lowered and the productivity is reduced. However, it is difficult to control the temperature and requires a large energy cost, and the cost effectiveness is extremely low.

  In addition, when the internal heat kiln furnace is used as a secondary combustion furnace, a large amount of diluted air is required to adjust the temperature in the furnace when the remaining carbon is burned. Since it is difficult to uniformly transmit heat into the internal heat kiln furnace, and furthermore, it is difficult to suppress fluctuations in the furnace temperature, there is a problem in that overburning of combustion products and uneven combustion are likely to occur.

  In addition, heavy oil combustion residual carbon and sulfur oxides from heavy oil burners used for normal heating cause contamination, resulting in decreased whiteness and variability at the product stage, making it difficult to equalize the quality of the resulting combustion products. Problems arise.

  Next, an example of a method for producing regenerated particles according to the present invention will be described with reference to the drawings.

  FIG. 1 is a flow chart of a production facility for regenerated particles according to an embodiment of the present invention. As will be described below, the production process of the regenerated particles includes a dehydration process, a drying / combustion process, and a pulverization process. Further, the deinking floss agglomeration process or granulation process, and a classification process between the processes. Etc. may be provided. This equipment is equipped with various sensors, and controls the state of combustibles, equipment, and processing speed.

  In the deinking process for producing waste paper pulp (not shown), the deinking floss separated from the pulp fiber is subjected to various operations and dehydrated by a known dehydration equipment (not shown). The raw material after dehydration is preferably in a high water content state of preferably 40% to 90%, more preferably 45% to 70%, and most preferably 50% to 60%.

  The material 10 after such dehydration is desirably pulverized to a particle size of 40 mm or less by a pulverizer (or pulverizer). The raw material 10 is cut out from the storage tank 12 and charged by a charging machine 15 from one side of the first combustion furnace 14 which is an internal heat kiln furnace in which the main body is placed horizontally and rotates around the central axis. An exhaust gas chamber 16 is provided on one side of the first combustion furnace 14, and an exhaust chamber 18 is provided on the other side. Hot air is blown from the other side of the first combustion furnace 14 through the discharge chamber 18, charged from the one side, and sequentially transferred to the other side as the first combustion furnace 14 rotates. It is designed to dry and burn.

  Here, it is desirable that the hot air blown into the first combustion furnace 14 has an oxygen concentration of 0.2% to 20%. The furnace temperature is preferably 300 ° C to 500 ° C, more preferably 400 ° C to 500 ° C, and most preferably 400 ° C to 450 ° C. Hot air is blown from a hot air generating furnace 20 provided with a burner 20A.

  From the exhaust gas chamber 16, exhaust gas subjected to drying and combustion is sent into the recombustion chamber 22. The fine powder of the combustion material contained in the exhaust gas is discharged from the lower part of the exhaust gas chamber 16 and reused. The exhaust gas is recombusted by the burner in the recombustion chamber 22, precooled by the precooler 24, passed through the heat exchanger 26, and discharged from the chimney 30 by the induction fan 28. Here, after raising the temperature of the outside air, the heat exchanger 26 is sent to the hot air generating furnace 20 and used for the hot air blown from the first combustion furnace 14 to recover the heat of the exhaust gas from the exhaust gas chamber 16. It is like that. The treatment of exhaust gas is effective for removing harmful substances contained in the exhaust gas.

  Combustion products that have undergone drying and combustion treatment in the first combustion furnace 14 are charged into a second combustion furnace 32 that is an external heat kiln furnace in which the main body is placed horizontally and rotates around the central axis. The particle size of the combusted material to be charged is preferably 40 mm or less. As a heat source in the second combustion furnace 32, it is preferable to use an electric adjustment that allows easy temperature control in the second combustion furnace 32 and easy temperature control in the longitudinal direction. Therefore, the first combustion is indirectly performed by an electric heater. It is desirable to be an external heating type combustion furnace in which the combustion product obtained from the furnace 14 is burned again.

  In the second combustion furnace 32, the oxygen concentration is preferably 5% to 20%, more preferably 10% to 20%, and most preferably by an air or oxygen supply mechanism (not shown) for adjusting the oxygen concentration. It burns so that it may become 10% -15%. As temperature, Preferably it is 550 to 780 degreeC, More preferably, it is 600 to 750 degreeC. The residence time in the second combustion furnace 32 is preferably 60 minutes to 240 minutes, more preferably 90 minutes to 150 minutes, and most preferably 120 minutes to 150 minutes, and the remaining carbon is completely burned.

  The regenerated particles that have been burned are cooled by a cooler 34, and then sorted by a particle size sorter 36 such as a vibration sieve, and the combustion is adjusted to a target particle size in a grinding process using a wet grinding machine or the like. The material is temporarily stored in the combustion product silo 38 and is sent to the application destination of the pigment or filler.

  In addition, although the case where deinking floss was used as a raw material was illustrated, even if it is a combustion thing which used as a raw material what mixed other papermaking sludges, such as papermaking sludge in a papermaking process, with deinking floss as a main raw material Good.

As mentioned above, although the outline | summary of the manufacturing process of regenerated particle was demonstrated, the detail and an application example are demonstrated below.
〔material〕
In the used paper pulp manufacturing process, in order to continuously produce used paper pulp of stable quality, used paper is selected and selected, and used paper of a certain quality is used. For this reason, the types, ratios, and amounts of inorganic substances brought into the used paper pulp manufacturing process are basically constant. Moreover, even when plastics such as vinyl and film, which cause fluctuations in unburned materials in the method for producing regenerated particles, are contained in the waste paper, these foreign matters are not before the deinking process to obtain deinking floss. Can be removed in stages. Accordingly, the deinking floss is a raw material for producing regenerated particles having extremely stable quality as compared with paper sludge generated in other processes such as a factory drainage process and a papermaking raw material preparation process.

The deinking floss referred to in the present invention refers to what is separated from pulp fibers in the deinking process for removing ink adhering to the used paper in the used paper processing process for producing the used paper pulp.
[Dehydration process]
For further dehydration of the deinking floss, known dehydration means can be used as appropriate. In one example in the present embodiment, the deinking floss is dehydrated by separating water from the deinking floss by a screen serving as a dewatering unit. In the screen, the deinking floss dehydrated to 90% to 97% is preferably sent to, for example, a screw press and further dehydrated to a predetermined moisture.

  If the moisture content of the raw material 10 after dehydration exceeds 70%, the temperature of the drying / combustion treatment in the first combustion furnace 14 will be lowered, the energy loss for heating will be great, and the non-uniform combustion of the raw material 10 will occur. It becomes easy and it becomes difficult to advance uniform combustion. Further, there are problems that the moisture in the exhaust gas to be discharged increases, the recombustion treatment efficiency is reduced in dioxin countermeasures, and the load on the exhaust gas treatment facility is increased. Moreover, when the moisture content of the raw material 10 after dehydration is as low as less than 40%, it causes excessive combustion of the deinking floss.

  As has been clarified in the above description, if dewatering of the deinking floss is performed in a multi-stage process and abrupt dewatering is avoided, the outflow of inorganic substances can be suppressed and there is no possibility that the deinking floss flock becomes too hard. In the dehydration treatment, an auxiliary agent for improving the dehydration efficiency such as an aggregating agent for aggregating the deinking floss may be added, but it is preferable to use an aggregating agent that does not contain iron. When iron is contained, it causes a problem of lowering the whiteness of the regenerated particles due to oxidation of iron.

  The deinking process of deinking floss is preferably adjacent to the process for producing regenerated particles in the present invention in terms of production efficiency, but a facility is provided in advance adjacent to the used paper pulp manufacturing process to transport the dehydrated product. It is also possible to carry it to a fixed quantity feeder by means of conveyance such as a truck or a belt conveyor, and supply it to the drying / combustion process from this fixed quantity feeder.

  In the operation of supplying the raw material 10 after dehydration to the first combustion furnace 14, the average particle size is preferably 40 mm or less, more preferably 3 mm to 30 mm, most preferably 5 mm to 20 mm by a pulverizer (or pulverizer). It is adjusted to be in the range. Furthermore, it is more desirable to grind so that the ratio of an average particle diameter of 40 mm or less may be 70% by weight or more. In order to achieve a combustion treatment that does not cause a heat change of the calcium carbonate contained in the deinking floss, it is preferable that the particle diameter of the raw material is uniform. However, if the average particle diameter is less than 3 mm, overburning easily occurs and exceeds 40 mm. This is because the average particle size has a problem that it is difficult to achieve uniform combustion up to the raw material core.

The ratio between the average particle size and the particle size was measured using a sample solution sufficiently dispersed by a stirring type disperser. The particle diameter in each combustion process was measured with a metal plate sieve based on JIS Z8801-2: 2000.
[First combustion process] (Drying and combustion process)
The raw material 10 is cut out from the storage tank 12 and supplied to the first combustion furnace 14. The first combustion furnace 14 has an internal heat kiln furnace system in which a main body is placed horizontally and rotates around a central axis, and is charged by a charging machine 15 from one side of the first combustion furnace 14. The internal heat kiln furnace heating means sends hot air generated in the hot air generator 20 from the discharge port side of the first combustion furnace 14 so as to counter-flow with the flow of the dehydrated product. An exhaust gas chamber 16 is provided on one side of the first combustion furnace 14, and an exhaust chamber 18 is provided on the other side. The raw material 10 is passed through the discharge chamber 18, hot air is blown from the other side of the first combustion furnace 14, charged from the one side, and sequentially transferred to the other side as the first combustion furnace 14 rotates. Drying and burning are performed.

  That is, in the main drying / combustion step, the dehydrated product is dried and burned gently from the supply port to the discharge port by drying and burning in the first combustion furnace 14 whose body is horizontally placed and rotates around the central axis. Combustion of organic components can be performed, pulverization of combustibles can be suppressed, and the degree of combustion of dehydrated products having various properties such as formation of aggregates, hard and soft, and particle alignment can be stably performed. In addition, the drying can be divided into separate steps and a blow-up type dryer can be inserted.

  Here, the hot air blown into the first combustion furnace 14 has an oxygen concentration of preferably 0.2% to 20%, more preferably 1% to 17%, and most preferably 7% to 15%. Yes.

  Since the oxygen concentration is consumed by combustion (oxidation) of the raw material 10, the oxygen concentration varies depending on the state of combustion. If the oxygen concentration is excessively low, it is difficult to achieve sufficient combustion. The oxygen in the first combustion furnace 14 is consumed by the combustion of the raw material 10 and the oxygen concentration is lowered. However, by blowing or exhausting oxygen-containing gas such as air by a hot air generator for burning, etc. The oxygen concentration can be maintained and adjusted, and further, the temperature in the first combustion furnace 14 can be finely adjusted by blowing or exhausting the oxygen-containing gas, and the raw material 10 is uniformly burned uniformly. be able to.

  The furnace temperature of the first combustion furnace 14 is preferably 300 ° C to 500 ° C, more preferably 400 ° C to 500 ° C, and most preferably 400 ° C to 450 ° C. In the first combustion furnace 14, it is preferable to combust in a temperature range of 300 ° C. to 500 ° C. for the purpose of gently burning organic matter that can be easily combusted and suppressing generation of residual carbon that is difficult to combust. When the temperature is excessively low, the organic matter is not sufficiently combusted. When the temperature is excessively high, overcombustion occurs, and calcium oxide is easily generated due to decomposition of calcium carbonate. Furthermore, when the temperature of the hot air exceeds 500 ° C., the drying and combustion proceeds locally faster than the grain alignment of the burned material having various properties such as hard and soft, so that the unburned particles on the particle surface and inside are not burned. It becomes difficult to make the difference in rate small and uniform.

  Hot air is blown from a hot air generating furnace 20 provided with a burner 20A.

  From the exhaust gas chamber 16, exhaust gas subjected to drying and combustion is sent into the recombustion chamber 22. The fine powder is discharged from the lower part of the exhaust gas chamber 16 and is mixed with the raw material and reused.

  The exhaust gas is recombusted by the burner in the recombustion chamber 22, precooled by the precooler 24, passed through the heat exchanger 26, and discharged from the chimney 30 by the induction fan 28. Here, the heat exchanger 26 raises the outside air and then sends it to the hot air generating furnace 20 to be used for the hot air blown from the first combustion furnace 14 so as to recover the heat of the exhaust gas from the exhaust gas chamber 16. It has become.

  The first combustion furnace 14 burns an easily combustible organic substance contained in the deinking floss, and burns it with a residence time of 30 minutes to 90 minutes under the above conditions in order to suppress the formation of residual carbon. preferable. Moreover, 40 minutes-80 minutes are more preferable in terms of the combustion of organic matter and production efficiency, and 50 minutes-70 minutes are the most preferable from the aspect of ensuring constant quality. If the combustion time is less than 30 minutes, sufficient combustion is not performed and the proportion of remaining carbon increases. When the combustion time exceeds 90 minutes, thermal decomposition of calcium carbonate due to overcombustion of the raw material 10 occurs, and the regenerated particles obtained become extremely hard.

  In particular, it is preferable to dry and burn the unburned rate of the combustion product supplied in the second combustion step of the next step to 2 to 20% by mass, more preferably 5 to 17% by mass, and most preferably 7% by mass. % To 12% by mass.

  By setting the unburned rate to 2 mass% to 20 mass%, the combustion in the second combustion process can be efficiently performed in a short time, and the hardness is low due to the stable heating in the external heating furnace. 80% or more, and at least 70% or more of high whiteness combustion products can be obtained. If the unburned material is less than 2% by mass, the energy cost in the first combustion furnace 14 is high, and the hardness of the combustion material may be relatively high. In some cases, the quality may be degraded such as a decrease in the degree.

[Second combustion process]
The combustion product that has undergone drying and combustion processing in the first combustion furnace 14 has an external heat jacket 31 in which the main body is placed horizontally and rotates around the central axis through the transfer flow path, and is a second combustion furnace 32 that is an external heat kiln furnace. Is charged.

  In the second combustion furnace 32, the combustion material is heated by external heat, and the transfer of the raw material 10 in the furnace is controlled by a lifter provided on the inner wall of the kiln furnace, so that the combustion is performed more slowly. Burn the unburned content.

  In the combustion in the second combustion furnace 32, residual organic matter that could not be combusted in the first combustion furnace 14, for example, residual carbon, is burned, so that the particles are smaller than the particle diameter of the raw material 10 supplied in the first combustion furnace 14. It is preferable to use a combustion product adjusted to a diameter. The particle size of the burned product after the drying / combustion step is adjusted so that the average particle size is preferably 10 mm or less, more preferably 1 mm to 8 mm, and most preferably 1 mm to 5 mm.

  If the average particle diameter at the entrance of the second combustion furnace 32 is less than 1 mm, there is a risk of overcombustion, and if the average particle diameter exceeds 10 mm, the remaining carbon is difficult to burn and combustion does not proceed to the core. It causes a problem that the whiteness of the obtained regenerated particles is lowered. In order to ensure stable production in the second combustion furnace 32, it is preferable to adjust the particle diameter so that the combustion product having an average particle diameter of 1 mm to 8 mm is 70% or more. Therefore, it is beneficial in terms of the possibility of practical use in terms of uniforming the quality of the obtained regenerated particles. Furthermore, when the classification is performed after drying as in the present embodiment, the combustion product of small-diameter particles can be surely removed, and the processing efficiency is improved.

  As an external heat source in the second combustion furnace 32, an electric heating type electric furnace in which temperature control in the second combustion furnace 32 is easy and temperature control in the longitudinal direction is easy is suitable. The combustion furnace 32 is desirable.

  By using electricity for the external heat, it becomes possible to finely adjust the temperature and control the internal temperature uniformly, control the degree of combustion of dehydrated products with various properties such as formation of aggregates, hard and soft, and granulation Alignment can be performed stably.

  Furthermore, the electric furnace can be provided with a temperature gradient arbitrarily by providing a plurality of electric heaters in the flow direction of the furnace, and can maintain the temperature of the combustion product for a certain period of time. Residual organic components in the combustion product that has passed through the first combustion furnace 14, particularly residual carbon, can be brought to zero as much as possible without causing uncombusted carbon dioxide to decompose in the second combustion furnace 32. Thus, regenerated particles with high whiteness can be obtained.

  In the second combustion furnace 32, the oxygen concentration is preferably set to 5% to 20%, more preferably 10% to 20%, and most preferably 10% to 15%. The oxygen concentration can be determined by controlling the amount of oxygen or air input to the second firing furnace (external heat kiln furnace) 32 by an appropriate means (illustration of a specific embodiment is omitted).

  If the oxygen concentration in the second combustion furnace 32 is less than 5%, there arises a problem that the combustion of the remaining carbon that is difficult to burn does not proceed.

  As temperature, Preferably it is 550 to 780 degreeC, More preferably, it is 600 to 750 degreeC.

  As described above, the second combustion furnace 32 needs to burn the residual organic matter that could not be burned in the first combustion furnace 14, particularly the remaining carbon, so that it is burned at a higher temperature than the first combustion furnace 14. When the combustion temperature is less than 550 ° C., it is difficult to sufficiently burn the residual organic matter. When the combustion temperature exceeds 780 ° C., the oxidation of calcium carbonate in the combustion product proceeds and the particles are hard. Problem arises.

  The residence time is preferably 60 minutes to 240 minutes, more preferably 90 minutes to 150 minutes, and most preferably 120 minutes to 150 minutes. In particular, the remaining carbon must be burned slowly at a high temperature that does not cause the decomposition of calcium carbonate as much as possible. If the residence time is less than 60 minutes, the remaining carbon is burnt in a short time, and 240 minutes. If it exceeds 1, the problem of decomposition of calcium carbonate occurs.

  Furthermore, it is preferable that combustion be performed in a residence time of 60 minutes or more in order to prevent overcombustion and ensure production in 240 minutes or less in stable production of combustion products.

  The average particle diameter of the combustion product discharged from the second combustion furnace 32 is preferably adjusted to 10 mm or less, more preferably 1 mm to 8 mm, and most preferably 1 mm to 5 mm.

  The regenerated particles whose combustion has been completed are preferably aggregates (regenerated particle aggregates), and after being cooled by the cooler 34, those having a target particle size are combusted by a particle size sorter 36 such as a vibration sieve. It is temporarily stored in the silo 38 and sent to the application destination of the pigment and filler.

In addition, although the case where the deinking froth was used as the raw material 10 was illustrated, it may be a combustion product obtained by appropriately mixing other papermaking sludge such as papermaking sludge in the papermaking process with the deinking floss as the main raw material.
[Crushing process]
In the method for producing regenerated particles based on the present embodiment, if necessary, a known dispersion / pulverization step is further provided, and a pigment for coating and a filler for internal addition are prepared by appropriately finely pulverizing to a necessary particle size. Can be used as

  In one example, the particles obtained after combustion are pulverized using a dry pulverizer such as a jet mill or a high-speed rotary mill, or a wet pulverizer such as an attritor, a sand grinder, or a ball mill. Regarding the optimum particle size for fillers, pigment applications, etc., the regenerated particles of this embodiment preferably have an average particle size of 2 to 5 μm.

  This is considered to be because the bulky effect is improved because the average particle size is larger than that of conventional calcium carbonate. Talc and clay have an average particle size larger than that of recycled filler and can be expected to have a bulky effect.

The particle size of the regenerated particles after the pulverization step was measured by a volume average particle size using a particle size distribution measuring device (laser type microtrack particle size analyzer: manufactured by Nikkiso Co., Ltd.).
[Attached process]
In this production facility, in order to obtain more stable quality, it is preferable to classify the particle size of the regenerated particles uniformly in each step, and feed back coarse and fine particles to the previous step. The quality can be further stabilized.

  In addition, it is preferable to granulate the deinked floss that has been subjected to dehydration in the previous stage of the drying process, and it is more preferable to classify the granulated product so that the particle diameter is uniform, The quality can be further stabilized by feeding back the fine granulated particles to the previous process. In granulation, a known granulation facility can be used, and facilities such as a rotary type, a stirring type and an extrusion type are suitable.

  As the raw material 10 of this production method, it is preferable to remove in advance other than what can be a raw material of regenerated particles, for example, sand with a pulper, a screen, a cleaner, etc. in the previous stage leading to the deinking process of the used paper pulp manufacturing process, It is preferable in terms of removal efficiency to remove plastic foreign substances, metals and the like. In particular, iron contamination is a causative agent for reducing the whiteness of fine particles due to oxidation, so it is recommended to avoid iron contamination and selectively remove it. Design or lining each process with materials other than iron, It is preferable to prevent iron from being mixed into the system due to abrasion or the like, and to further remove iron selectively by installing a high magnetic material such as a magnet in the drying / classifying equipment.

  Furthermore, the regenerated particles produced by the method for producing regenerated particles according to the present embodiment preferably have a ratio of calcium, silica and aluminum in terms of oxides of 30 to 82: 9 to 35 in elemental analysis of fine particles using an X-ray microanalyzer. : 9-35, more preferably 40-82: 9-30: 9-30, most preferably 60-82: 9-20: 9-20.

  By including calcium, silica, and aluminum in a mass ratio of 30 to 82: 9 to 35: 9 to 35 in terms of oxides, the specific gravity is light and excessive aqueous solution absorption is suppressed, so that dehydration in the dehydration process is good. Thus, it is possible to reduce the ratio of unburned matter in the drying / combustion process and the risk of excessive hardness due to sintering in the combustion process.

  As a method for adjusting the ratio of the present embodiment, the main point is to adjust the raw material composition in the deinking floss, but in the drying / combustion process and the combustion process, the coating floss and preparation process with a clear origin It is also possible to adjust by means of containing floss in the process by spraying or the like, or means of containing incinerator scrubber lime.

  For example, using deinked floss as the main raw material, neutral papermaking drainage sludge and wastewater sludge from the coated paper manufacturing process are used to adjust calcium in the regenerated particles, and opacity improvers are used to adjust silica. Newspaper manufacturing wastewater sludge with a large amount of white carbon added, papermaking wastewater sludge that uses an acid papermaking system and other sulfuric acid bands to adjust aluminum, and high-quality papermaking process that uses a lot of clay Drainage sludge in can be used.

In addition, the regenerated particles obtained by this production method have a weight loss (rate) of 50% or more in the decomposition (change to calcium oxide) of calcium carbonate that occurs in the vicinity of 700 ° C. in the differential thermal analysis using the differential thermal thermogravimetric simultaneous measurement device. As described above, it is preferable to control the combustion of the deinking froth based on the present embodiment, since the progress of the oxidation of the calcium component can be suppressed more accurately and the particles can be prevented from becoming hard.
[About the lifter of the second combustion furnace (external heat kiln furnace)]
As described above together with the reason for adoption, parallel to the inner wall of the secondary combustion furnace (external heat kiln furnace) 32 parallel to the spiral lifter and / or the axis from one end side to the other end side. By disposing the lifter, it is possible to achieve uniform combustion of the raw material 10 and uniform quality.

  For this secondary combustion furnace (external heat kiln furnace) 32, a known rotary combustion apparatus as shown in FIG. 2 (a) with its internal structure and FIG. Used for.

  That is, the secondary combustion furnace (external heat kiln furnace) 32 is configured to be rotationally driven by a rotational drive means (not shown), and has a charging part 32a at one end and a discharge part at the other end. (Not shown) is provided, and the other end is provided with a combustion burner 20A (not shown) for introducing combustion gas into the cylindrical main body 32b. The inner surface of the fireproof wall 32c on the side of the insertion portion 32a of the cylindrical main body 32b has a plurality of spirals (eight in the illustrated example) that are inclined at an inclination angle of 45 ° to 70 ° with respect to the axis of the cylindrical main body 32b. A cylindrical lifter 32d protrudes at equal intervals through a bracket 32e, and a parallel lifter 32f of an appropriate length parallel to the axial center of the cylindrical main body 32b is provided at the other end side in the circumferential direction. A plurality (eight in the illustrated example) are provided at intervals, and a plurality of rows (eight in the illustrated example) bracket 32g are provided in the axial direction.

  The fireproof wall 32c is preferably made of fireproof castable or fireproof brick, and the helical lifter 32d and the parallel lifter 32f are made of metal such as a stainless steel plate having heat resistance, for example. Therefore, durability and strength can be sufficiently secured without using an expensive heat-resistant material, and heat transfer efficiency is higher than that of a refractory lifter, so that the heat efficiency can be further improved. In particular, it is desirable that the spiral lifter 32d and the parallel lifter 32f are arranged in this order from the combusted material input portion 32a side to the discharge side as described above.

  According to the secondary combustion furnace (external heat kiln furnace) 32 configured as described above, the content charged from the charging portion 32a is first appropriately amounted toward the other end side by the spiral lifter 32d. While being lifted and dropped each time, the organic components resulting from the raw material 10 efficiently come into contact with the combustion gas (combustible gas) generated by gasification, and then lifted and dropped by the parallel lifter 32f. By repeating the operation to perform efficient contact with the combustion gas (combustible gas), the contents can be combusted with high heat exchange efficiency. In particular, by controlling the amount of the content fed into the parallel lifter 32f by the spiral lifter 32d, the content can be properly lifted and dropped at the parallel lifter 32f, and the content can be burned uniformly and efficiently. Can be done automatically. Further, since there is no fear of damage to the refractory, there is no decrease in the purity of the fired product, and its production capacity can be improved.

  In the above-described embodiment, the spiral lifter 32d and the parallel lifter 32f are provided side by side, but only one of them may be provided as necessary.

  The regenerated particles obtained as described above have a whiteness of preferably 75 to 85%, more preferably 80 to 85%, and there is little variation in whiteness. In addition, when the regenerated particles obtained by the production method described above are used for the book paper, the whiteness is high and the bulk is high as compared with the case of using conventionally known regenerated particles and commercially available calcium carbonate. Yes, it is possible to obtain book paper that does not peel off during printing.

  The regenerated particles obtained by the production method according to the present invention have an average particle size larger than the average particle size (1 to 2 μm) of conventionally known calcium carbonate, and the regenerated particles are fixed between the fibers so that the bulky effect is obtained. In addition, since the aluminum of the reclaimed filler is cationic, it has a strong fixability to the fiber and can reduce the blending amount compared to calcium carbonate, so the ash content can be lowered, and the bulk effect and surface strength are improved. As a result, it is considered that paper peeling at the time of printing can be reduced.

  In the book paper, the content of aluminum oxide is preferably 10 to 35% by mass, more preferably 15 to 25% by mass, out of all inorganics including the inorganics brought from the recycled particles. When the aluminum content is less than 10%, the improvement in fixability is reduced. On the other hand, if the aluminum content exceeds 35%, the cationicity becomes too strong and reacts with the papermaking chemicals, which may cause agglomerates and black foreign matters such as pitch, which is not desirable.

  In this embodiment, the regenerated particles as described above can be used alone, or such regenerated particles and heavy calcium carbonate, light calcium carbonate, talc, clay, kaolin, titanium dioxide, which are usually used as internal fillers. In addition, at least one filler selected from inorganic fillers such as synthetic silica and aluminum hydroxide, and synthetic polymer fine particles such as polystyrene resin and urea formaldehyde resin can be used in combination. Of course, these two or more types can be used in combination.

  The content of recycled particles in the base paper (relative to the base paper) is preferably 5 to 20% by mass, more preferably 10 to 15% by mass. When the content exceeds 20% by mass, the density is lowered and the bulk is not increased. When the content is less than 5% by mass, the whiteness decreases.

  As a raw material pulp used for the book paper in this embodiment, LBKP is used as a main raw material, and 30-50 mass% of mechanical pulp is mix | blended in all the pulp. Mechanical pulp is bulky but has low whiteness. On the other hand, LBKP has high whiteness but low bulk. In order to balance whiteness and bulk, it is optimal to blend 50% by mass or more of LBKP and 30 to 50% by mass of mechanical pulp.

  There is no restriction | limiting in particular about the manufacturing method of LBKP, A conventionally well-known means can be used.

  Moreover, although there is no restriction | limiting in particular in mechanical pulp, Since coniferous tree comes out rather than hardwood, it is suitable. There is no restriction | limiting in particular also about the manufacturing method of mechanical pulp, The groundwood pulp (GP), refiner pulp groundwood pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemiground pulp which are mechanically ground. Either mechanical pulping methods such as (CGP) and semi-chemical pulp (SCP) may be used.

  Moreover, there is no restriction | limiting in particular also about the bleaching method of mechanical pulp, A conventionally well-known means can be used. In addition, conventionally known waste paper pulp, NBPK, etc. may be blended.

  Examples of the used paper for the used paper pulp include newspaper used paper, upper white used paper, Kent used paper, imitation used paper, and OA used paper.

  Moreover, in order to make it more bulky, a conventionally known bulking agent can also be used. The type and blending amount of the bulking agent are not particularly limited. However, increasing the blending amount lowers the surface strength and may cause paper peeling during printing. Therefore, it is desirable to keep the amount to the minimum necessary amount.

  As additives to be added to the paper slurry, known ones can be used. For example, starch, vegetable gum, aqueous cellulose derivative and the like are used as a paper strength enhancer, and rosin, starch and CMC (carboxyl are used as sizing agents. Methyl cellulose), polyvinyl alcohol, alkyl ketene dimer, ASA (alkenyl succinic anhydride), neutral rosin and the like, and polyacrylamide and copolymers as the yield improver. Furthermore, you may add colorants, such as dye and a pigment, as needed.

  Further, conventionally known flocculants, coagulants, and sulfuric acid bands can be added to fix the filler to the pulp, and are not particularly limited.

  In order to improve whiteness and whiteness for viewing, conventionally known fluorescent dyes, coloring dyes, and coloring pigments can be arbitrarily selected.

  Next, examples of the present invention will be described.

  Various factors in the production process of regenerated particles were changed as shown in Tables 1 and 2 to obtain regenerated particles, and the quality of these various regenerated particles was examined. The results are shown in the right column of Table 2. In addition, the unburned rate after the 1st combustion process of Table 1 and the evaluation of the quality of Table 2 were performed as follows.

  (Unburnt rate): The crucible containing the sample was placed in an electric muffle furnace preheated to 600 ° C., burned, and after complete combustion, the unburned content was calculated from the change in weight before and after burning.

  (Wire abrasion degree): It measured by plastic wire abrasion degree (Nippon Filcon Co., Ltd. 3 hours) and slurry concentration 2 weight%.

  (Productivity): Raw material dewatering efficiency, productivity, and power required for crushing are evaluated in 4 stages. The most efficient condition is ◎, the best is 〇, water efficiency, productivity, pulverization Those that found problems were marked with △, and those that were difficult to operate were marked with ×.

  (Quality stability): For each item of fineness obtained by a predetermined method, whiteness, particle diameter, and production amount at a fixed time interval, the degree of variation is measured and ranked in the order of small variation. ◎ from place to place, ◯ from 7th to 16th place, △ from 17th to 28th place, and x from below.

  (Appearance): The color of the regenerated particles was visually judged and classified into white and gray.

表２に示すように、本発明に係る製造方法により得た低温再生粒子(実施例１〜２８)は、（比較例１〜３の場合に較べ）品質面で優れていることが分かる。

As shown in Table 2, it can be seen that the low temperature regenerated particles (Examples 1 to 28) obtained by the production method according to the present invention are superior in quality (compared to Comparative Examples 1 to 3).

Next, in order to confirm the effect of the book paper according to the present invention, the raw material adjustment conditions were changed as shown in Table 3, and as a solid content to the raw material pulp, a coagulant 200 ppm (manufactured by Eka Chemicals, model number PL1410), After adding 100 ppm of a flocculant (manufactured by Eka Chemicals, model number NP320), the raw material slurry was subjected to a paper machine. Moreover, in the paper machine, the oxidized starch was coated on both sides with a gate roll coater at 0.5 g / m ² to obtain a book paper sample with a US basis weight of 70 g / m ² , and various evaluations were performed as follows. went.

  (Ash content): Measured in accordance with JIS P 8251.

  (Aluminum oxide content): The content of aluminum oxide in the inorganic material of the non-coated type inkjet recording paper was measured by elemental analysis using an X-ray microanalyzer.

  (Product whiteness): Measured according to JIS P 8148.

(Paper peeling): The obtained sample is cut into a flat size and printed on a Roland flat printing machine at 10,000 printing speeds per minute to determine the degree of paper peeling from white spots on the paper. evaluated.
○: Almost no white spots Δ: Slight white spots but no problem in practical use ×: White spots are conspicuous and cannot be used

表３の右欄から分かるように、本発明に係る低温再生粒子を填料として含有させ、書籍用紙を製造すれば、白色度が高く、嵩高な書籍用紙を得ることができる。(実施例１０１〜１１５参照)

As can be seen from the right column of Table 3, when a book paper is produced by containing the low temperature regenerated particles according to the present invention as a filler, a book paper with high whiteness and bulk can be obtained. (See Examples 101-115)

  The present invention contains deinked floss separated from pulp fibers in a deinking process of waste paper processing equipment as a main material, and the main material contains regenerated particles obtained through dehydration, drying, combustion, and pulverization processes in a base paper. It can be applied as book paper.

10 Material 12 Reservoir 14 First Combustion Furnace (Internal Heat Kiln Furnace)
15 Charging machine 16 Exhaust gas chamber 18 Exhaust chamber 20 Hot air generating furnace 22 Recombustion chamber 24 Precooler 26 Heat exchanger 31 External heat jacket 32 Second combustion furnace (external heat kiln furnace)
32b Tubular body 32c Fire wall 32d Spiral lifter 32f Parallel lifter 34 Cooler 36 Particle size sorter 38 Combustion furnace silo

Claims (3)

LBKP is the main raw material, and the blending ratio of mechanical pulp measured in accordance with JIS P8120 (1998) is 30 to 50%. A book paper coated with a resin, comprising at least regenerated particles obtained by the following production steps (A) to (E) as the filler.
(B) Deinking floss separated from pulp fibers in the deinking process of the used paper processing equipment for producing used paper pulp is used as the main raw material, and (b) the main raw material is dehydrated to a moisture content of 40 to 90% in the dehydrating process. , (c) the dehydrated the main raw material is dried and burned at least first and second temperature of 300 ℃ ~500 ℃ in the first combustion furnace of a combustion step consisting of two stages, (d) the combustion and main raw material after it was again burned in the second combustion furnace, reproduction particles and pulverized by (e) pulverizing step. The whiteness of the regenerated particles is 75 to 85%, the ash content measured according to JIS P8251 (2003) is 5 to 20% by mass, and the density is 0.4 to 0.7 g / cm ³ . The book paper according to claim 1, wherein the whiteness according to JIS P8148 (2001) is 70 to 80%.   It consists of a base paper containing LBKP as a main raw material, blended with mechanical pulp so that the blending ratio of mechanical pulp measured in accordance with JIS P8120 (1998) is 30 to 50%, and internally added with a filler. A book paper manufacturing method in which a water-soluble resin is applied to the surface of paper, wherein regenerated particles included at least as the filler are manufactured by the following manufacturing processes (a) to (e). Production method.
(B) Deinking floss separated from pulp fibers in the deinking process of the used paper processing equipment for producing used paper pulp is used as the main raw material, and (b) the main raw material is dehydrated to a moisture content of 40 to 90% in the dehydrating process. (C) drying and burning the dehydrated main raw material at a temperature of 300 ° C. to 500 ° C. in a first combustion furnace of a combustion process consisting of at least first and second stages; and (d) the burned main raw material. After being burned again in the second combustion furnace, (e) pulverization is performed in a pulverization step to obtain regenerated particles.

Images