JP4904389B2 - Method for producing fine paper powder and method for producing resin composition containing fine paper powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing fine paper flour capable of manufacturing the fine paper flour without applying large environmental load. <P>SOLUTION: The method for manufacturing the fine paper flour includes a first fine grinding process for grinding the coarsely ground paper flour using vertical roller mills 10 and 20 or a mortar type mill 40 to obtain the fine paper flour with an average particle size of &ge;50 and &lt;150 &mu;m and a second fine grinding process for grinding fine paper flour, wherein fine paper flour with an average particle size of &ge;25 and &lt;50 &mu;m is mixed with the fine paper flour obtained in the first fine grinding process, using the vertical roller mills or the mortar type mill to obtain the fine paper flour with the average particle size of &ge;25 and &lt;50 &mu;m. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention, fine paper powder producing method for producing fine paper powder, and a method for the production of fine paper powder-containing resin composition containing the obtained fine paper powder by this manufacturing method.

  In recent years, a large amount of waste paper has been discharged from offices, publishers, and paper manufacturers. Paper is a functional material having a structure with high added value, which has been subjected to advanced processing that makes cellulose fibers fine and soft at the processing stage from wood or the like. Therefore, waste paper is originally a functional material having a structure with high added value, and in addition, it becomes a raw material with virtually no environmental impact. Thus, it has been proposed to use a paper-containing resin composition in which crushed waste paper is mixed in a resin as a material for molding.

  For example, in Patent Document 1, composite paper having polyethylene resin on both sides or one side is shredded into shredders such as a shredder or a crusher or a crusher into small pieces, granules, and powders of about 1 mm to 5 mm square, A paper-containing resin composition in which a synthetic resin component such as polyethylene is mixed so that the shredded paper component is 50% by weight or more is disclosed.

  In Patent Document 2, recovered waste paper such as laminated paper for liquid containers is pulverized to a particle size of 0.5 mm to 2.5 mm, and a resin such as polyethylene or polypropylene is mixed so that the pulverized paper is 51% by mass or more. A paper-containing resin composition is disclosed.

  In Patent Document 3, a low-burning component mainly composed of powdered paper powder having a particle size of 50 μm or more and 200 μm or less by pulverizing waste paper or the like is more than 50% by weight and is mainly composed of a thermoplastic resin. A paper-containing resin composition for molding processing containing 30% by weight or more and less than 50% by weight of a high combustion component is disclosed.

Japanese Patent Laid-Open No. 10-138241 JP 2007-45863 A JP 2001-181511 A

  However, the paper-containing resin compositions disclosed in Patent Documents 1 and 2 contain shredded paper of about 1 mm to 5 mm square, crushed paper with a particle size of 0.5 mm to 2.5 mm, and large sized crushed paper. . When such a resin composition is used for injection molding of a complicated molded product having a fine structure, pulverized paper that does not exhibit fluidity even when heated prevents the resin composition from flowing, resulting in defects such as poor filling. Since it is easy to occur and transferability is inferior, a high quality molded product cannot be obtained with a good yield.

  Further, when a complex molded product having a fine structure is injection molded using a resin composition containing a powdery paper powder having a particle size of 50 μm or more and 200 μm or less as disclosed in Patent Document 3, The pulverized paper that does not show fluidity even when heated prevents the resin composition from flowing, and defects such as poor filling are likely to occur, and the transferability is poor. Therefore, a high-quality molded product cannot be obtained with high yield.

  If the particle size of the paper powder contained in the paper-containing resin composition is reduced to less than 50 μm by the inventors of the present invention, the transferability is excellent, and high-quality molded products can be injection-molded with high yield. all right.

  However, when paper powder is pulverized using a pulverizer such as a rod mill, ball mill, pan mill, pin mill, etc., the average particle size is about 100 μm, and even if the operation of the pulverizer is continued, the paper fibers are intertwined. It turned out to be cottony and it was found that the pulverization did not proceed.

  In addition, when paper dust is pulverized using a vertical roller mill, Yakuken type mill, or stone mill type mill, the advantage of using waste paper whose pulverization efficiency is remarkably reduced and the environmental impact is substantially zero when the particle size is about 50 μm or less. It turns out that there is a problem of fading.

In view of the above points, the present invention provides a fine paper powder production method capable of producing fine paper powder having a particle diameter of less than 50 μm without imposing a large environmental load, and a fine paper powder containing the fine paper powder obtained by this production method. It aims at providing the manufacturing method of a paper dust containing resin composition.

  The fine paper powder manufacturing method of the present invention includes a first fine pulverization step in which coarsely pulverized paper powder is pulverized using a vertical roller mill or a Yakuken type mill to obtain fine paper powder having an average particle size of 50 μm or more and less than 150 μm. The fine paper powder obtained by mixing the fine paper powder obtained in the first fine grinding step with fine paper powder having an average particle size of 25 μm or more and less than 50 μm is pulverized using a vertical roller mill or a Yakken type mill, and the average particle size is 25 μm. And a second pulverizing step for obtaining fine paper powder of less than 50 μm.

  According to the fine paper powder manufacturing method of the present invention, in the first fine pulverization step, the coarsely pulverized paper powder is pulverized to an average particle size of 50 μm or more and less than 150 μm using a vertical roller mill or a Yakken type mill. Since the pulverization in the first fine pulverization step is pulverization within a range in which the pulverization efficiency is excellent, the environmental load is small. In the first fine pulverization step, it is also preferable to pulverize the paper powder to an average particle size of 50 μm or more and less than 100 μm.

  Further, in the second fine pulverization step, fine paper powder obtained by mixing fine paper powder having an average particle size of 25 μm or more and less than 50 μm into fine paper powder having an average particle size of 50 μm or more and less than 150 μm obtained in the first fine pulverization step, It grind | pulverizes to an average particle diameter of 25 micrometers or more and less than 50 micrometers using a type | mold roller mill or a Yakuken type mill. Since the pulverization in the second fine pulverization process is excellent in pulverization efficiency, the environmental load is small. Since fine fine paper powder having a particle size of 25 μm or more and less than 50 μm collides with coarse fine paper powder having a particle size of 50 μm or more and less than 150 μm at a high speed, and the fine fine paper powder is crushed, it is estimated that the pulverization efficiency is excellent. If the average particle size is less than 25 μm, it is not preferable because the environmental load increases.

  The vertical roller mill and the Yakuken type mill used in the first and second fine grinding steps may be separate or the same. A stone mill is not suitable for mass production because of its small grinding capacity.

  In the fine paper powder manufacturing method of the present invention, the second fine pulverization step may be provided after the second fine pulverization step, by selecting fine paper powder having a particle size of 25 μm or more and less than 50 μm and less than a predetermined particle size. In the step, it is preferable to mix fine paper powder having an average particle diameter of 25 μm or more and less than 50 μm and having the predetermined particle diameter or more.

  In this case, when the resin composition containing the obtained fine paper powder is molded and processed, since there is no paper powder having a particle size of 25 μm or more and less than 50 μm, the transferability is excellent and the quality is high. Molded products can be obtained with good yield.

The method for producing a resin composition containing fine paper powder for molding according to the present invention is a fine paper powder having an average particle size of 25 μm or more and less than 50 μm obtained by the fine paper powder production method of the present invention. At least one of polyethylene, polypropylene, olefin-based elastomer, polystyrene, acrylonitrile-styrene copolymer synthetic resin, acrylonitrile-butadiene-styrene copolymer synthetic resin, nylon, polybutylene terephthalate, and polyethylene terephthalate so as to be in the range of% by weight. It is characterized by being mixed with one kind of resin.

Schematic which shows the pulverization apparatus which concerns on embodiment of this invention. Schematic which shows the Yakuken type mill used for the fine grinding apparatus which concerns on the deformation | transformation of embodiment of this invention.

  An embodiment of a method for producing fine paper powder of the present invention will be described with reference to the drawings.

  This fine paper powder manufacturing method pulverizes waste paper as a raw material to fine paper powder having an average particle size of 25 μm or more and less than 50 μm, and has a coarse pulverization step and a fine pulverization step. Waste paper includes waste newspaper, magazine waste, printed waste paper, packaging waste paper, corrugated waste paper, OA waste paper and other waste paper, broken paper and waste paper generated during the manufacture of virgin paper, magazine waste, and abrasive powder. , Shredder scraps and the like. Waste paper is discharged in large quantities from offices, publishers, paper manufacturers, etc., and it is evaluated that the environmental impact is virtually zero. In addition, the average particle diameter of paper powder shall be measured with a laser diffraction type particle size distribution measuring apparatus (manufactured by Marvern Instruments Ltd., Mastersizer S type).

  In the coarse pulverization step, the waste paper is pulverized into a piece of paper of about several mm to several tens mm, preferably 2 mm to 4 mm square, using a coarse pulverizer such as a roll crusher, a hammer crusher, or a cutter mill. When the waste paper is made of roll-like or sheet-like broken paper or broken paper, a cutter or a cutting machine may be used as the coarse pulverizer. In addition, when the waste paper is several mm or less, such as polishing powder obtained by polishing a book or shredder waste, a coarse pulverization step is not required.

  The fine pulverization step is a step of finely pulverizing the paper powder pulverized in the coarse pulverization step to obtain fine paper powder having an average particle size of 25 μm or more and less than 50 μm, and includes a first fine pulverization step and a second fine pulverization step. . Here, as shown in FIG. 1, the fine pulverization step is performed using a fine pulverizer in which two vertical roller mills 10 and 20 are connected in series.

  In the first fine pulverization step, the coarse paper powder pulverized in the coarse pulverization step is finely pulverized to an average particle size of 50 μm or more and less than 150 μm using the vertical roller mill 10.

  The vertical roller mill 10 represents a roller mill, and is a roller type pulverizer that is also simply called a “roller mill”. Although not shown in detail, the saddle type roller mill 10 includes a rotary table that is rotationally driven by a motor inside a cylindrical crushing chamber (housing) 11 and a plurality of scissors arranged with a gap in the rotational direction of the rotary table. And a mold-shaped crushing roller. The crushing roller is a free roller configured so that a load is applied to the rotary table by hydraulic pressure, a spring, or the like, and rotates following the rotation of the rotary table. Along with the rotation of the rotary table, paper powder is caught between the land of the crushing roller and the inner wall of the crushing chamber and pulverized. Instead of the rotary table that rotates while supporting the lower part of the grinding roller, a suspension member that rotates while supporting the upper part of the grinding roller (suspending the grinding roller) may be used. A concave groove may be formed on the inner wall of the pulverization chamber, but it is preferable that the inner surface of the pulverization chamber is smooth because paper dust may accumulate in the concave groove and the pulverization effect may be reduced.

  The paper powder pulverized in the coarse pulverization step is supplied from the supply hopper (raw material supply port) 12 into the pulverization chamber 11 via the supply screw 13 and moves to the outer periphery of the rotary table by the centrifugal force of the rotary table. Is mainly pulverized by being caught between the pulverizing roller and the pulverizing roller. Air is introduced from the outside into the crushing chamber 11, and the finely pulverized paper powder is blown up to the upper part 14 of the crushing chamber 11 by the air blown up by the vanes. Fine paper powder having an average particle size of 50 μm or more and less than 150 μm is discharged from a supply pipe (supply duct) 15 through a classifier (rotary blade separator) (not shown) installed in the upper part 14 of the crushing chamber 11. Is done. The particle size of the fine paper powder discharged from the supply pipe 15 can be adjusted by the number of rotations of the rotating blades of the classifier. Although not shown, it is preferable to quantitatively supply the coarse paper powder into the crushing chamber 11 using a rotary bubble, a screw feeder or the like.

  In this manner, the 2 mm to 4 mm square coarse paper powder is finely pulverized by the vertical roller mill 10 to an average particle size of 50 μm or more and less than 150 μm. Paper powder having a particle size of 150 μm or more is hit by a rotating blade, falls due to its own weight, and is pulverized again.

  In the second fine pulverization step, the fine paper powder pulverized in the first fine pulverization step is finely pulverized to a mean particle size of 25 μm or more and less than 50 μm using the vertical roller mill 20. The configuration of the vertical roller mill 20 is the same as that of the vertical roller mill 10.

  The coarse fine paper powder finely pulverized to a mean particle size of 50 μm or more and less than 150 μm by the vertical roller mill 10 is supplied from the supply pipe 15 into the pulverization chamber 21 of the vertical roller mill 20. Specifically, coarse fine paper powder is supplied from the supply pipe 15 into the pulverization chamber 21 through a dust collector 16, a rotary valve 17, a screw feeder (not shown), a supply hopper (raw material supply port) 22, and a supply screw 23. Is done. Further, fine fine paper powder having an average particle size of 25 μm or more and less than 50 μm is supplied from the supply hopper (chute) 22 into the grinding chamber 21 by an operator. Thereby, coarse fine paper powder and fine fine paper powder are mixed in the crushing chamber 21.

  The fine paper powder moves to the outer periphery of the rotary table by the centrifugal force of the rotary table, and is pulverized by being caught between the land of the pulverizing roller and the inner wall of the pulverizing chamber 21, and swirls as the rotary table rotates. Due to the air current, the coarse fine paper powder collides with the fine fine paper powder, and the coarse fine paper powder is crushed. Air is introduced into the crushing chamber 21 from the outside, and fine paper powder that has been crushed and made fine by the air blown up by the vanes blows up to the upper portion 24 of the crushing chamber 21. Fine fine paper powder having an average particle size of 25 μm or more and less than 50 μm is supplied from a supply pipe (supply duct) 25 through a classifier (rotary blade separator) (not shown) installed in the upper part 24 of the crushing chamber 21. Discharged.

  In this way, coarse fine paper powder having an average particle size of 50 μm or more and less than 150 μm is finely pulverized by the vertical roller mill 20 to an average particle size of 25 μm or more and less than 50 μm. Paper powder having a particle size of 50 μm or more is hit by a rotating blade, falls due to its own weight, and is pulverized again. Note that it is not preferable to finely pulverize to an average particle size of less than 25 μm because the environmental load required for fine pulverization increases and the advantage of using waste paper that has substantially no environmental load is reduced.

  Fine fine paper powder having an average particle size of 25 μm or more and less than 50 μm supplied to the supply pipe 25 is collected in the collection box 31 via the dust collector 26 and the rotary valve 27.

  By performing the fine pulverization step as described above, fine paper powder having an average particle size of 25 μm or more and less than 50 μm can be obtained with excellent pulverization efficiency. The reason why the grinding efficiency is excellent is that in the second fine grinding step, fine fine paper powder having a particle size of 25 μm or more and less than 50 μm collides with coarse fine paper powder having a particle size of 50 μm or more and less than 150 μm, and the fiber This is presumed to be caused by cutting and coarse fine paper powder. It is difficult to further pulverize only with fine paper powder of the same size, and the pulverization efficiency is very poor.

  Carbon dioxide emissions from resource collection to fine paper dust production calculated by life cycle assessment support software (JEMAI-LCA Pro Ver. 212, manufactured by Japan Association for Industrial Environment Management) is 0.7 kg / paper dust It is preferably 1 kg or less. According to the present embodiment, the carbon dioxide emission amount in the production process until the fine paper powder having an average particle diameter of 45 μm was obtained from the cutting waste paper of the magazine as a raw material was 0.3 kg / paper powder 1 kg. The power consumption required for producing 1 kg of fine paper powder having an average particle size of 40 μm was 1.75 kwh.

  Depending on the type of waste paper used as a raw material and the operating conditions of the vertical roller mills 10, 20, for example, the operating time, the rotation speed of the rotary table, the amount and ratio of fine fine paper powder to be input to the vertical roller mill 20, etc. The average particle size and processing capacity of the fine paper powder to be produced are determined. Therefore, the operating conditions suitable for the required average particle size of fine paper powder, processing capacity, etc. may be determined as appropriate through experiments.

  Moreover, the fine paper powder manufacturing method of the present invention is not limited to this embodiment. For example, in the present embodiment, in the second fine pulverization step, an operator supplies fine fine paper powder having an average particle diameter of 25 μm or more and less than 50 μm from the supply hopper 22 into the pulverization chamber 21. However, it is not limited to this. For example, a branch pipe may be provided in the supply pipe 25, and a part of fine fine paper powder flowing in the supply pipe 25 may be supplied from the supply hopper 22 into the crushing chamber 21 and refluxed. Thereby, automatic driving | operation becomes possible.

  It is also preferable to provide the dust collector 26 with a sorting device for sorting fine paper powder having a particle size of 25 μm or more and less than 50 μm, for example, less than 40 μm. A sorting process for sorting fine paper powder of less than 40 μm is performed using a sorting device, and only the fine paper powder of less than 40 μm sorted in the sorting process is collected in the collection box 31. Then, fine particles having an average particle size of 25 μm or more and less than 50 μm and a particle size of 40 μm or more are introduced into the crushing chamber 21 from the supply hopper 22. Thereby, the pulverization efficiency is improved, and fine fine paper powder having a particle size of less than 40 μm can be obtained.

  Further, in the vertical roller mills 10 and 20, the case where the supply ports to the crushing chambers 11 and 21 of the supply hoppers 12 and 22 and the supply pipe 15 are provided on the side of the rotary table is illustrated. Any or all of them may be provided above the rotary table.

  Further, different vertical roller mills 10 and 20 are used in the first and second fine grinding steps, but the same vertical roller mill may be used in common. This simplifies the equipment.

  Further, instead of the saddle type roller mills 10 and 20, a Yakuken type mill 40 as shown in FIG. 2 may be used. The Yakken mill 40 is a pulverizer that mainly performs airflow pulverization. Although not shown in detail, the Yakken-type mill 40 is supported by the main shaft 42 and a main shaft 42 that is rotationally driven by a motor inside an outer cylindrical housing 41 having a V-shaped groove 41a at the bottom. And a plurality of disk-shaped rotating rollers 43 that are vertically rotatable. The rotation roller 43 is disposed with a clearance (clearance) between the rotation roller 43 and the groove 41 a, and the interval can be adjusted by the adjustment handle 44.

  The paper dust is supplied into the crushing chamber (housing) 41 from the raw material input port (hopper) 45 and is accumulated in the groove 41 a due to the bottom shape of the crushing chamber 41. The paper dust accumulated in the groove 41a is sheared and crushed by a rotating roller 43 that rotates as the main shaft 42 rotates. Furthermore, the entangled coarse fine paper powder is centrifuged and loosened by the airflow swirling as the main shaft 42 rotates, and the coarse fine paper powder is crushed by the collision of the fine paper powder.

  When the Yakken type mill 40 is used only for the first fine pulverization step, the coarsely pulverized paper powder is introduced from the raw material inlet 45. Then, the coarse fine paper powder finely pulverized to a mean particle size of 50 μm or more and less than 150 μm by the Yakken mill 40 is pulverized from the supply hopper 22 by the vertical roller mill 20 together with the fine fine paper powder having an average particle size of 25 μm or more and less than 50 μm. An operator enters the chamber 21.

  On the other hand, when the Yakken type mill 40 is used only for the second fine pulverization step, the coarse fine paper powder finely pulverized by the vertical roller mill 10 to an average particle size of 50 μm or more and less than 150 μm is fine with an average particle size of 25 μm or more and less than 50 μm. Along with the fine paper powder, an operator enters the crushing chamber 41 of the Yakken type mill 10 from the raw material supply port 45. In this case, the power consumption required to produce 1 kg of fine paper powder having an average particle size of 40 μm was 1.5 kwh or less.

  Further, the Yakken type mill 40 may be used in the first and second pulverizing steps. In this case, different ones may be used in each step, or a common one may be used. Since the internal temperature of the Yakken type mill 40 does not increase so much by operation, it can be operated continuously for a long time.

  Hereinafter, embodiments of the resin composition containing fine paper powder of the present invention will be described.

  This resin composition containing fine paper powder is such that the weight ratio of fine paper powder having an average particle size of 25 μm or more and less than 50 μm obtained by the fine paper powder production method of the above embodiment is in the range of 50 wt% to 60 wt%. It is obtained by mixing with a resin and can be suitably used as a material for molding. In addition, a weight ratio means the ratio with respect to the total weight of a fine paper powder containing resin composition.

  When the fine paper powder content is less than 50% by weight, functions such as strain absorbability at the time of molding based on the flexible structure of the paper powder are suppressed, and environmental performance is also lowered. On the other hand, when the fine paper powder content exceeds 60% by weight, the paper powder that does not exhibit dissolution fluidity at the molding temperature hinders the fluidity of the resin, increases the possibility of molding failure, and increases the molding pressure. Energy consumption increases and environmental performance decreases.

  The resin is polyethylene, polypropylene, olefin elastomer, polystyrene, AS resin (acrylonitrile-styrene copolymer synthetic resin), ABS resin (acrylonitrile-butadiene-styrene copolymer synthetic resin), nylon, PBT (polybutylene terephthalate), PET ( Polyethylene terephthalate), and the weight ratio is 40% by weight or more and less than 50% by weight.

It contains a surface modifying agent in order to enhance the kneading of the fine paper powder and the resin, to facilities to surface modification treatment. Surface modifiers include various silane coupling agents, higher fatty acids such as stearic acid, various higher fatty acid esters, higher fatty acid amides, ethylene oligomers, polyethylene wax, maleic acid modified wax and maleic ester modified wax, low molecular weight crystalline polyolefin Ru der any one or two or more of. The silane coupling agent enhances the interaction between the inorganic particles and the resin and improves the kneadability with the resin by adsorbing to the inorganic pigment contained in the paper powder. Other surface modifiers improve kneadability by enhancing the interaction between paper dust and resin.

The surface modifier, it contains in the range of 5 wt% or less than 0.1 wt%. If the addition amount of the surface modifier is less than 0.1% by weight, a sufficient kneadability improving effect cannot be obtained, and if it exceeds 5% by weight, there is a high possibility that adverse effects such as an exudation phenomenon on the surface of the molded product will occur.

  Moreover, it is preferable to contain a resin modifier. The resin modifier is preferably one or two of maleic acid-modified polyolefin, olefin-maleic anhydride copolymer, maleic acid-modified wax and maleic ester-modified wax. These resin modifiers are mixed with a resin, particularly an olefin resin, to introduce a polar group, enhance the interaction with paper dust, and improve kneadability.

  The resin modifier is preferably contained in the range of 0.5 wt% to 10 wt%. If the addition amount of the resin modifier is less than 0.5% by weight, the modification effect is poor, and if it exceeds 10% by weight, the inherent properties of the resin such as rigidity and strength may be impaired.

  The fine paper powder-containing composition can be produced using an extruder. Fine paper powder and resin, as well as a surface modifier and a resin modifier, are introduced as necessary from an inlet (hopper) provided at the rear end of the extruder. The inside of the extruder is heated, and the fine paper powder and the resin are kneaded by the rotating screw to form a molten mixture in which the fine paper powder is dispersed substantially uniformly in the resin. This molten mixture is extruded from a die (die) provided at the front end of the extruder to produce a fine paper powder-containing resin composition having a predetermined cross-sectional shape. Depending on the lip shape of the die, the fine paper powder-containing resin composition is formed into a pellet shape, a plate shape, a sheet shape, or the like. The pellet-like fine paper powder-containing resin composition can be suitably used as a material for molding such as injection molding, blow molding, inflation molding, vacuum molding, melt compression molding, press molding and the like.

Thus, since it contains fine paper powder having an average particle size of 25 μm or more and less than 50 μm, if it is molded using this fine paper powder-containing resin composition, transferability is excellent, so high-quality molded products can be obtained with high yield. Obtainable. In addition, since waste paper is used as a raw material, resources are effectively used, and the environmental load in the waste paper crushing process is small, so that environmental performance is excellent. Furthermore, since the size of the fine paper powder contained is as fine as an average particle size of 25 μm or more and less than 50 μm, the molded product exhibits excellent properties of paper such as flexibility and high strain absorption .

Example 1
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Next, the first fine pulverization step was performed using a vertical roller mill, and the second fine pulverization step was performed using a Yakken type mill, and these steps were connected to obtain fine paper powder having an average particle size of 45 μm. The amount of carbon dioxide emitted from the fine paper powder production was 0.3 kg / kg of paper powder.

Add 5 g of silane coupling agent (Shin-Etsu Chemical Co., Ltd., KBM-502) and 1 L of water to 5 kg of this fine paper powder, mix the emulsified liquid stirred at high speed with a mixer uniformly with a Henschel mixer, and circulate hot air Dried overnight in a formula drier. Next, 50 parts by weight of the dried fine paper powder and 5 parts by weight of low molecular weight low density polyethylene (Novatec LD LJ902, manufactured by Nippon Polyethylene Co., Ltd.) are uniformly mixed with a Henschel mixer, and a polypropylene homopolymer ( 45 parts by weight (manufactured by Nippon Polyethylene Co., Ltd., Novatec PP MA3AQ) were introduced into the twin-screw extruder through the second inlet and pelletized. By using the raw material, it was possible to stably pelletize the strand without breaking the strand in the pellet manufacturing process. This pellet was used for injection molding to obtain a bowl-shaped molded product. This molded product showed a good appearance without spots due to poor dispersion of fine paper powder. A box-shaped molded product was also injection molded, but it was good with little molding warpage .

(Example 2)
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Next, the first fine pulverization step was performed using a vertical roller mill, and the second fine pulverization step was performed using a Yakken type mill, and these steps were connected to obtain fine paper powder having an average particle size of 45 μm. The amount of carbon dioxide emitted from the fine paper powder production was 0.3 kg / kg of paper powder.

To 5 kg of this fine paper powder, 25 g of stearic acid (Wako Pure Chemical Industries, Ltd., reagent grade 1) was added and mixed uniformly with a Henschel mixer. The stearic acid content fine paper powder 50 parts by weight of poly profile propylene homopolymer (Nippon Polyethylene Co., Novatec PP MA3AQ) 45 parts by weight and the acid-modified polypropylene (Mitsui Chemicals, Inc., Admer QE800) and 5 parts by weight of a Henschel mixer Mixed and pelletized using a twin screw extruder. By using the raw material, it was possible to stably pelletize the strand without breaking the strand in the pellet manufacturing process. This pellet was used for injection molding to obtain a bowl-shaped molded product. This molded product showed a good appearance without spots due to poor dispersion of paper powder. A box-shaped molded product was also injection molded, but it was good with little molding warpage .

Example 3
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Next, the first fine pulverization step was performed using a vertical roller mill, and the second fine pulverization step was performed using a Yakken type mill, and these steps were connected to obtain fine paper powder having an average particle size of 45 μm. The amount of carbon dioxide emitted from the fine paper powder production was 0.3 kg / kg of paper powder.

50 parts by weight of this fine paper powder, 2.5 parts by weight of olefin oligomer (Mitsui Chemicals, EXELEX 30200B) and 7.5 parts by weight of low molecular weight low density polyethylene (Nippon Polyethylene Co., Ltd., Novatec LD LJ902) are mixed with a Henschel mixer. from the first input port and uniformly mixed, poly profile propylene homopolymer was introduced into (manufactured by Japan polyethylene Corporation, Novatec PP MA3AQ) respectively 40 parts by weight from the second input port tandem extruder and pelletized. By using the raw material, it was possible to stably pelletize the strand without breaking the strand in the pellet manufacturing process. This pellet was used for injection molding to obtain a bowl-shaped molded product. This molded product showed a good appearance without spots due to poor dispersion of paper powder. A box-shaped molded product was also injection molded, but it was good with little molding warpage .

Example 4
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Next, the first and second fine pulverization steps were performed by connecting these steps using a vertical roller mill to obtain fine paper powder having an average particle size of 45 μm. The amount of carbon dioxide emitted from the production of fine paper powder was 0.167 kg / kg of paper powder.

50 parts by weight of this fine paper powder was fed into the twin screw extruder from the first inlet, and 50 parts by weight of polypropylene homopolymer (Novatec PP MA3AQ, manufactured by Nippon Polyethylene Co., Ltd.) from each of the second inlets, and pelletized. By using the raw material, it was possible to stably pelletize the strand without breaking the strand in the pellet manufacturing process. This pellet was used for injection molding to obtain a bowl-shaped molded product. This molded product showed a good appearance without spots due to poor dispersion of fine paper powder. A box-shaped molded product was also injection molded, but it was good with little molding warpage .

(Comparative Example 1)
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Subsequently, the first fine pulverization step was performed using a vertical roller mill, and the second fine pulverization step was performed using a Yakken type mill, and these steps were connected to obtain fine paper powder having an average particle diameter of 20 μm. Carbon dioxide emissions in the production of fine paper powder are 2.1 kg / 1 kg of paper powder, and the advantage of using waste paper, whose environmental impact is substantially zero, as a raw material has been reduced .

(Comparative Example 2)
The waste paper from cutting the paperboard was coarsely pulverized to 2 mm square with a cutter mill. Subsequently, it was pulverized to obtain a paper powder having an average particle size of 300 μm. The amount of carbon dioxide emitted from the production of paper powder was 0.08 kg / paper powder 1 kg.

Add 5g of silane coupling agent (Shin-Etsu Chemical Co., Ltd., KBM-502) and 1L of water to 5kg of this paper powder, and uniformly mix the emulsified liquid stirred at high speed with a Henschel mixer. Dried overnight in a dryer. Then, the dried low-molecular weight polyethylene in fine paper powder 50 parts by weight (manufactured by Japan Polyethylene Corporation, Novatec LD LJ902) 5 parts by weight were uniformly mixed by a Henschel mixer first inlet, poly-flop Ropirenhomo 45 parts by weight of a polymer (manufactured by Nippon Polyethylene Co., Ltd., Novatec PP MA3AQ) was charged into a twin screw extruder through the second charging port, and pelletized. Pellets could be stably formed without strand breakage. This pellet was used for injection molding to obtain a comb-shaped product. However, the tip portion of the comb teeth became insufficiently filled, and if sufficient filling was attempted, burrs were generated, resulting in poor molding and reduced productivity.

  DESCRIPTION OF SYMBOLS 10,20 ... Vertical roller mill, 11, 21 ... Crushing chamber, 12, 22 ... Supply hopper, 15, 25 ... Supply pipe, 16, 26 ... Dust collector, 31 ... Accumulation box, 40 ... Yakuken type mill, 41 ... Crush chamber 41a ... groove, 42 ... main shaft, 43 ... rotating roller, 45 ... raw material inlet.

Claims (3)

A first finely pulverizing step of pulverizing the coarsely pulverized paper powder using a vertical roller mill or a Yakken type mill to obtain fine paper powder having an average particle size of 50 μm or more and less than 150 μm;
Fine paper powder in which fine paper powder having an average particle size of 25 μm or more and less than 50 μm is mixed with the fine paper powder obtained in the first fine pulverization step is pulverized using a vertical roller mill or a Yakuken type mill, and the average particle size is 25 μm or more. And a second finely pulverizing step for obtaining fine paper powder of less than 50 μm. After the second fine pulverization step, comprising a selection step of obtaining fine paper powder having a particle size of 25 μm or more and less than 50 μm and less than a predetermined particle size,
2. The fine paper powder manufacturing method according to claim 1, wherein in the second pulverization step, fine paper powder having an average particle diameter of 25 μm or more and less than 50 μm and the predetermined particle diameter or more is mixed.   A fine paper powder having an average particle size of 25 μm or more and less than 50 μm obtained by the method for producing fine paper powder according to claim 1 or 2, so that the weight ratio is in the range of 50 wt% to 60 wt%. Molding characterized by being mixed with at least one resin selected from the group consisting of elastomer, polystyrene, acrylonitrile-styrene copolymer synthetic resin, acrylonitrile-butadiene-styrene copolymer synthetic resin, nylon, polybutylene terephthalate, and polyethylene terephthalate A process for producing a fine paper powder-containing resin composition for processing.

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