JP6687089B2 - Complex - Google Patents

Description

  The present invention relates to a sheet manufacturing apparatus and a sheet manufacturing method.

  It has long been practiced to deposit a fibrous substance and to exert a bonding force between the deposited fibers to obtain a sheet-shaped or film-shaped molded body. A typical example thereof is the production of paper by papermaking (papermaking) using water. At present, the papermaking method is widely used as one of the methods for producing paper. In the paper produced by the papermaking method, for example, cellulose fibers derived from, for example, wood are entangled with each other and partially bound to each other by a binder (paper strengthening agent (starch paste, water-soluble resin, etc.)). Many have a structure.

  According to the papermaking method, the fibers can be deposited with good uniformity, and when a paper strengthening agent or the like is used to bond the fibers, the paper strengthening agent is also uniformly distributed in the paper surface. It can be dispersed (distributed) in a good state. However, since the papermaking method is a wet method, it is necessary to use a large amount of water, and after paper is formed, it is necessary to perform dehydration / drying, etc., and energy and time consumed for that are very large. Also, the water used must be properly treated as waste water. Therefore, it has become difficult to meet the recent demands for energy saving, environmental protection and the like. Further, the apparatus used for the papermaking method often requires a large-scale utility such as water, electric power, and drainage equipment, and it is difficult to downsize it. From these viewpoints, a method called a dry method, which uses no or almost no water, is expected as a method for producing paper instead of the papermaking method.

  For example, in the technique described in Patent Document 1, in an air-laid nonwoven fabric containing a highly water-absorbent resin, an attempt to bond the fibers with a heat-fusible synthetic resin is disclosed.

JP, 2011-099172, A

  However, in the technique described in Patent Document 1, the heat-fusible resin is in the form of powder, and there is a danger of desorption from the fibers during air laying. Paragraph 0013 of the document describes that if the heat-fusible powder is too small, it will pass through the mesh conveyor (mesh belt) eyes, making it difficult to fix it between the fibers. Therefore, it is described in the same document that it is preferable to use a heat-fusible resin powder having a relatively large particle diameter (20 mesh pass, 300 mesh on).

  However, if the particle size of the resin is large, the uniformity of resin distribution in the product sheet may be impaired. Therefore, in order to uniformly disperse the resin between the fibers, it is desirable that the particle size of the resin is smaller.

  When forming a web by air laid, suction is generally performed from below the mesh belt. Then, if the particle size of the resin is made smaller than the size of the openings of the mesh belt, it is considered that the resin is easily detached from the fibers during web formation. Therefore, even if the particle size of the resin is reduced, it is necessary to devise a method that makes it difficult for the resin to be detached from between the fibers.

  One of objects of some aspects of the present invention is to provide a sheet manufacturing apparatus and a sheet manufacturing method using a heat-fusible resin that is difficult to be separated from between fibers.

  The present invention has been made to solve at least a part of the above problems, and can be realized as the following aspects or application examples.

One aspect of the sheet manufacturing apparatus according to the present invention is
A mixing section for mixing the fiber and the composite in the atmosphere,
A forming unit for depositing the mixture mixed in the mixing unit and heating to form a sheet,
Equipped with
The composite is a resin particle in which at least a part of the surface is coated with inorganic fine particles,
The absolute value of the average charge amount of the composite is 40 μC / g or more.

  According to the sheet manufacturing apparatus according to this application example, since the composite, in which at least a part of the surface is resin particles coated with inorganic fine particles, is mixed with the fiber in the air, the composite is charged during the mixing and the fiber is mixed. And the composite is less likely to detach from the fibers when the web is formed. Then, in this state, the composite and the fibers are bound (heat-bonded) to each other, so that a sheet having good strength can be manufactured.

In the sheet manufacturing apparatus according to the present invention,
The volume-based average particle diameter of the resin particles may be 25 μm or less.

  According to such a sheet manufacturing apparatus, since the composite is as small as 25 μm or less, it is easy to mix and disperse between the fibers. In addition, since the particles of the composite are small and the weight is light, the composite is less susceptible to the influence of gravity and is less likely to be detached from the web or sheet.

In the sheet manufacturing apparatus according to the present invention,
The volume-based average particle diameter of the inorganic fine particles may be 40 nm or less.

  When the inorganic fine particles have an average particle diameter of 40 nm or less, the charge amount of the composite can be further increased.

In the sheet manufacturing apparatus according to the present invention,
The composite may not be divided into the resin and the inorganic fine particles during mixing in the mixing section.

  According to such a sheet manufacturing apparatus, not only the inorganic fine particles are attached to the resin in the state of the composite, but also the composite is so integrated as not to be separated into the resin and the inorganic fine particles during mixing. , It is more difficult for the inorganic fine particles to fall off during mixing.

In the sheet manufacturing apparatus according to the present invention,
The molding unit may include a discharge unit that discharges the mixture, a mesh belt that deposits the mixture, and a suction unit that sucks a gas containing the mixture discharged through the mesh belt.

  By sucking through the mesh belt, the possibility that the composite will be detached from the fibers is increased, but according to the sheet manufacturing apparatus of this application example, the composite is detached from the fibers even if the suction unit is provided. Can be suppressed.

In the sheet manufacturing apparatus according to the present invention,
The content of the inorganic fine particles in the composite may be 0.1% by mass or more and less than 4% by mass.

  According to such a sheet manufacturing apparatus, a sufficient charging effect can be obtained even if the content of the inorganic fine particles in the composite is as small as 0.1% by mass or more and less than 4% by mass. Therefore, the amount of the inorganic fine particles used can be reduced.

In the sheet manufacturing apparatus according to the present invention,
The mixing section may include a plurality of rotating sections having rotating blades, and the fibers and the composite may be mixed by passing through the rotating section.

  According to such a sheet manufacturing apparatus, by allowing the fiber and the composite to pass through the rotating unit having the rotating blades, the composite is more likely to be charged and is more difficult to be detached from the fiber.

One aspect of the sheet manufacturing method according to the present invention is
A step of mixing the fiber, a composite of resin and inorganic fine particles, in air,
Depositing a mixture of the fibers and the composite, heating and molding,
including.

  According to such a sheet manufacturing method, since the composite which is the resin particles coated with the inorganic fine particles is mixed with the fiber in the air, the composite is easily charged during the mixing and adheres to the fiber, and the web is formed. When formed, the composite does not easily detach from the fibers, and a sheet having good uniformity in strength and the like can be manufactured.

The figure which shows the sheet manufacturing apparatus which concerns on this embodiment typically. The schematic diagram which shows some examples of the cross section of the composite_body | complex which concerns on embodiment. The schematic diagram showing an example of the suction device concerning an example of an experiment.

  Hereinafter, some embodiments of the present invention will be described. The embodiments described below describe examples of the invention. The present invention is not limited to the following embodiments, and includes various modifications that are carried out without changing the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

1. Sheet manufacturing apparatus The sheet manufacturing apparatus of the present embodiment includes a mixing unit that mixes fibers and a composite in the atmosphere, and a molding unit that deposits the mixture mixed in the mixing unit and heats it to form a sheet. , And at least a part of the surface of the composite is coated with inorganic fine particles, and the absolute value of the average charge amount of the composite is 40 μC / g or more.

1.1. Configuration First, an example of the sheet manufacturing apparatus according to the present embodiment will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a sheet manufacturing apparatus 100 according to this embodiment.

As shown in FIG. 1, the sheet manufacturing apparatus 100 includes a supply unit 10, a manufacturing unit 102, and a control unit 140. The manufacturing unit 102 manufactures a sheet. The manufacturing unit 102 includes a crushing unit 12, a defibrating unit 20, a classifying unit 30, a sorting unit 40, a first web forming unit 45, and a mixing unit 50.
The stacking unit 60, the second web forming unit 70, the sheet forming unit 80, and the cutting unit 90.

  The supply unit 10 supplies the raw material to the crushing unit 12. The supply unit 10 is, for example, an automatic charging unit for continuously charging the raw material into the crushing unit 12. The raw material supplied by the supply unit 10 includes fibers such as waste paper and pulp sheet.

  The crushing unit 12 cuts the raw material supplied by the supply unit 10 into pieces in the air. The shape and size of the strip are, for example, a strip of several cm square. In the illustrated example, the crushing unit 12 has a crushing blade 14, and the crushing blade 14 can cut the fed raw material. As the crushing unit 12, for example, a shredder is used. The raw material cut by the crushing unit 12 is received by the hopper 1 and then transferred (conveyed) to the defibrating unit 20 via the pipe 2.

  The defibrating unit 20 defibrates the raw material cut by the crushing unit 12. Here, "to disentangle" means to disentangle and unravel the raw material (object to be disentangled) formed by binding a plurality of fibers into each fiber. The defibrating unit 20 also has a function of separating substances such as resin particles, ink, toner, and anti-bleeding agent attached to the raw material from the fibers.

  What has passed through the defibrating unit 20 is referred to as a “defibrated material”. "Disentangled material" includes, in addition to disentangled disentangled fibers, resin particles (resin for binding a plurality of fibers) separated from the fibers when disentangled, ink, toner, etc. In some cases, the colorant, the anti-bleeding agent, the paper strength enhancer and other additives are included. The shape of the disentangled defibrated material is a string shape or a ribbon shape. The disentangled defibrated material may exist in a state not entangled with other disentangled fibers (independent state), or entangled with other disentangled defibrated material to form a lump. It may exist in a state (a state in which a so-called “damage” is formed).

  The defibration unit 20 performs defibration in the air (in the air) by a dry method. Specifically, an impeller mill is used as the defibrating unit 20. The defibrating unit 20 has a function of sucking the raw material and generating an air flow for discharging the defibrated material. As a result, the defibrating unit 20 can suck the raw material together with the airflow from the inlet 22 by the airflow generated by the defibrating unit 20, defibrate the material, and convey the material to the outlet 24. The defibrated material that has passed through the defibration unit 20 is transferred to the classification unit 30 via the tube 3.

  The classifying unit 30 classifies the defibrated material that has passed through the defibrating unit 20. Specifically, the classifying unit 30 separates and removes relatively small defibrated materials and those having a low density (resin particles, coloring agents, additives, etc.). This can increase the proportion of fibers that are relatively large or have a high density in the defibrated material.

  An airflow classifier is used as the classifying unit 30. An airflow classifier generates a swirling airflow and separates it according to the difference in centrifugal force due to the size and density of the objects to be classified, and the classification point can be adjusted by adjusting the speed and centrifugal force of the airflow. it can. Specifically, a cyclone, an elbow jet, an eddy classifier, or the like is used as the classifying unit 30. In particular, the cyclone as shown in the figure can be suitably used as the classifying unit 30 because of its simple structure.

  The classification unit 30 includes, for example, an introduction port 31, a cylindrical portion 32 to which the introduction port 31 is connected, an inverted conical portion 33 located below the cylindrical portion 32 and continuous with the cylindrical portion 32, and an inverted conical portion 33. Has a lower discharge port 34 provided at the center of the lower part of the above, and an upper discharge port 35 provided at the center of the upper part of the cylindrical portion 32.

  In the classifying unit 30, the air flow on which the defibrated material introduced from the introduction port 31 is placed changes into a circumferential motion in the cylindrical unit 32. As a result, the introduced defibrated material is subjected to a centrifugal force, and the classifying unit 30 causes the defibrated material to have a higher density (first classified material) than the resin particles or the ink particles in the defibrated material. Among them, resin particles smaller than fibers and having a low density can be separated into resin particles, coloring agents, additives and the like (second classified material). The first classified product is discharged from the lower discharge port 34 and introduced into the sorting unit 40 via the pipe 4. On the other hand, the second classified material is discharged from the upper discharge port 35 to the receiving portion 36 via the pipe 5.

  The sorting unit 40 introduces the first classified material (defibrated material defibrated by the defibrating unit 20) that has passed through the classifying unit 30 from the introduction port 42, and selects according to the length of the fiber. As the sorting unit 40, for example, a sieve is used. The sorting unit 40 has a net (filter, screen), and is included in the first classified product, and has fibers or particles smaller than the mesh opening size (those that pass through the net, the first sorted product) and the net. Fibers larger than the size of the mesh, undisentangled pieces, and lumps (those that do not pass through the net, the second sorted product) can be separated. For example, the first sorted product is received by the hopper 6 and then transferred to the mixing unit 50 via the pipe 7. The second sorted material is returned from the discharge port 44 to the defibrating unit 20 via the pipe 8. Specifically, the selection unit 40 is a cylindrical sieve that can be rotated by a motor. As the net of the selection unit 40, for example, a wire net, an expanded metal obtained by extending a notched metal plate, or a punching metal in which holes are formed in the metal plate by a pressing machine or the like is used.

  The first web forming unit 45 conveys the first sorted material that has passed through the sorting unit 40 to the mixing unit 50. The first web forming unit 45 includes a mesh belt 46, a stretching roller 47, and a suction unit (suction mechanism) 48.

  The suction unit 48 can suck the first sorted material dispersed in the air through the opening (mesh opening) of the sorting unit 40 onto the mesh belt 46. The first sorted material is deposited on the moving mesh belt 46 to form the web V. The basic configurations of the mesh belt 46, the stretching roller 47, and the suction section 48 are the same as those of the mesh belt 72, the stretching roller 74, and the suction mechanism 76 of the second web forming section 70 described later.

  The web V is formed into a soft and swelled state containing a large amount of air by passing through the sorting section 40 and the first web forming section 45. The web V deposited on the mesh belt 46 is put into the tube 7 and conveyed to the mixing section 50.

  The mixing unit 50 mixes the first sorted product that has passed through the sorting unit 40 (the first sorted product transported by the first web forming unit 45) and the additive containing resin. The mixing unit 50 includes an additive supply unit 52 that supplies an additive, a pipe 54 that conveys a selected product and the additive, and a blower 56. In the illustrated example, the additive is supplied from the additive supply unit 52 to the pipe 54 via the hopper 9. The tube 54 is continuous with the tube 7.

  In the mixing section 50, an air flow is generated by the blower 56, and the first sorted product and the additive can be transported while being mixed in the pipe 54. The mechanism for mixing the first selected product and the additive is not particularly limited, and may be a device that agitates with a blade that rotates at high speed, or a device that uses the rotation of a container such as a V-type mixer. It may be.

  As the additive supply unit 52, a screw feeder as shown in FIG. 1 or a disc feeder not shown is used. The additive supplied from the additive supply unit 52 contains a resin for binding a plurality of fibers. When the resin is supplied, the plurality of fibers are not bound. The resin melts when passing through the sheet forming unit 80 and binds the plurality of fibers.

  The resin supplied from the additive supply unit 52 is a thermoplastic resin or a thermosetting resin, for example, AS resin, ABS resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, polyethylene terephthalate, Polyphenylene ether, polybutylene terephthalate, nylon, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, polyether ether ketone, and the like. You may use these resins individually or in mixture as appropriate. The additive supplied from the additive supply unit 52 may be in the form of fiber or powder.

  In addition to the resin that binds the fiber, the additive supplied from the additive supply unit 52 may be a colorant for coloring the fiber or may prevent aggregation of the fiber depending on the type of sheet to be manufactured. In order to prevent the fibers from burning, a coagulation inhibitor for suppressing the burning may be contained. The mixture (mixture of the first classification product and the additive) that has passed through the mixing unit 50 is transferred to the deposition unit 60 via the pipe 54.

  The deposition unit 60 introduces the mixture that has passed through the mixing unit 50 through the introduction port 62, loosens the entangled defibrated material (fibers), and disperses the defibrated material (fibers) in the air. Further, when the additive resin supplied from the additive supply unit 52 is fibrous, the deposition unit 60 loosens the entangled resin. Thereby, the deposition unit 60 can deposit the mixture on the second web forming unit 70 with good uniformity.

  As the deposition unit 60, a rotating cylindrical sieve is used. The deposition unit 60 has a net, and causes fibers or particles (those that pass through the net) contained in the mixture that has passed through the mixing unit 50 to be smaller than the size of the mesh opening. The configuration of the deposition unit 60 is the same as the configuration of the selection unit 40, for example.

  The “sieve” of the deposition unit 60 does not have to have a function of selecting a specific object. That is, the “sifter” used as the deposition unit 60 means that it is provided with a net, and the deposition unit 60 may drop all of the mixture introduced into the deposition unit 60.

  The second web forming unit 70 forms the web W by accumulating the passing matter that has passed through the accumulating unit 60. The second web forming unit 70 includes, for example, a mesh belt 72, a stretching roller 74, and a suction mechanism 76.

  While moving, the mesh belt 72 deposits the passing matter that has passed through the openings (mesh openings) of the deposition unit 60. The mesh belt 72 is stretched by a tension roller 74, and it is difficult for a passing object to pass therethrough and allows air to pass therethrough. The mesh belt 72 moves as the tension roller 74 rotates. The web W is formed on the mesh belt 72 by continuously depositing the passing objects that have passed through the deposition unit 60 while the mesh belt 72 continuously moves. The mesh belt 72 is made of, for example, metal, resin, cloth, or non-woven fabric.

  The suction mechanism 76 is provided below the mesh belt 72 (on the side opposite to the deposition unit 60 side). The suction mechanism 76 can generate a downward airflow (airflow from the deposition unit 60 toward the mesh belt 72). The suction mechanism 76 can suck the mixture dispersed in the air by the deposition unit 60 onto the mesh belt 72. As a result, the discharge speed from the deposition unit 60 can be increased. Further, the suction mechanism 76 can form a downflow in the falling path of the mixture, and can prevent the defibrated material and the additives from being entangled with each other during the falling.

  As described above, by passing through the deposition section 60 and the second web forming section 70 (web forming step), the soft and bulged web W containing a large amount of air is formed. The web W deposited on the mesh belt 72 is conveyed to the sheet forming unit 80.

  In the illustrated example, a humidity control unit 78 that controls the humidity of the web W is provided. The humidity control section 78 can add water or water vapor to the web W to adjust the amount ratio between the web W and water.

  The sheet forming unit 80 pressurizes and heats the web W accumulated on the mesh belt 72 to form the sheet S. In the sheet forming unit 80, by applying heat to the mixture of the defibrated material and the additive mixed in the web W, the plurality of fibers in the mixture are bound to each other via the additive (resin). You can

  As the sheet forming unit 80, for example, a heating roller (heater roller), a hot press molding machine, a hot plate, a warm air blower, an infrared heater, or a flash fixing device is used. In the illustrated example, the sheet forming unit 80 includes a first binding portion 82 and a second binding portion 84, and the binding portions 82 and 84 each include a pair of heating rollers 86. By configuring the binding portions 82 and 84 as the heating roller 86, the web W can be continuously conveyed as compared with the case where the binding portions 82 and 84 are configured as a plate-shaped pressing device (flat plate pressing device). The sheet S can be molded. The number of heating rollers 86 is not particularly limited.

  The cutting unit 90 cuts the sheet S formed by the sheet forming unit 80. In the illustrated example, the cutting unit 90 includes a first cutting unit 92 that cuts the sheet S in a direction intersecting the conveyance direction of the sheet S, and a second cutting unit 94 that cuts the sheet S in a direction parallel to the conveyance direction. ,have. The second cutting unit 94 cuts the sheet S that has passed through the first cutting unit 92, for example.

  As described above, a single-cut sheet S having a predetermined size is formed. The cut single-cut sheet S is discharged to the discharge unit 96.

1.2. Fiber In the sheet manufacturing apparatus 100 of the present embodiment, the raw material is not particularly limited, and a wide range of fiber materials can be used. Examples of fibers include natural fibers (animal fibers, plant fibers) and chemical fibers (organic fibers, inorganic fibers, organic-inorganic composite fibers), and more specifically, cellulose, silk, wool, cotton, hemp, kenaf, flax. , Ramie, jute, Manila hemp, sisal, conifer, hardwood, etc., fiber, rayon, lyocell, cupra, vinylon, acrylic, nylon, aramid, polyester, polyethylene, polypropylene, polyurethane, polyimide, carbon, glass, metal Examples of the fiber include fibers, which may be used alone, may be appropriately mixed and used, or may be used as a regenerated fiber which has been refined. Examples of the raw material include used paper and used cloth, and may contain at least one kind of these fibers. Further, the fiber may be dried, or may contain or be impregnated with a liquid such as water or an organic solvent. Further, various surface treatments may be performed. Further, the material of the fiber may be a pure substance or a material containing a plurality of components such as impurities, additives and other components.

  As described above, the sheet manufacturing apparatus 100 of the present embodiment can use various kinds of raw materials, but among these, used paper and pulp sheets containing cellulose fibers have relatively high hydrophilicity and are less likely to be charged, because cellulose is relatively hydrophilic. The effect of improving the adhesion between the composite and the fiber, which will be described later, becomes more remarkable than in the case of using other fibers.

The fiber used in the present embodiment has an average diameter (when the cross section is not a circle, the maximum length in the direction perpendicular to the longitudinal direction, Alternatively, the diameter (circle equivalent diameter) of the circle assuming a circle having an area equal to the area of the cross section is 1 μm or more and 1000 μm or less on average, preferably 2 μm or more and 500 μm or less, more preferably 3 μm or more and 200 μm. It is the following.

  The length of the fiber used in the sheet manufacturing apparatus 100 of the present embodiment is not particularly limited, but is one independent fiber, and the length along the longitudinal direction of the fiber is 1 μm or more and 5 mm or less, preferably, It is 2 μm or more and 3 mm or less, and more preferably 3 μm or more and 2 mm or less. When the length of the fiber is short, the strength of the sheet may be insufficient because it is difficult to bind with the composite, but a sheet having sufficient strength can be obtained within the above range.

  The average length of the fibers is 20 μm or more and 3600 μm or less, preferably 200 μm or more and 2700 μm or less, and more preferably 300 μm or more and 2300 μm or less as a length-length weighted average fiber length. Furthermore, the fiber length may have a variation (distribution), and in a distribution obtained with an n number of 100 or more for one independent fiber length, when a normal distribution is assumed, σ May be 1 μm or more and 1100 μm or less, preferably 1 μm or more and 900 μm or less, and more preferably 1 μm or more and 600 μm or less.

  The thickness and length of the fiber can be measured by various optical microscopes, scanning electron microscopes (SEM), transmission electron microscopes, fiber testers, and the like. Further, in the case of microscopic observation, pretreatment of the observation sample is appropriately performed as necessary to perform cross-sectional observation and observation in a state where both ends of one independent fiber are pulled so as not to break as necessary. It is possible to do.

  In the sheet manufacturing apparatus 100 of the present embodiment, the fiber raw material is defibrated by the defibrating unit 20, and is conveyed to the mixing unit 50 as the first selected material via the classifying unit 30 and the selecting unit 40. In addition, when the function of the classification unit 30 (removal of resin particles and ink particles from the defibrated material) can be performed on the web V by the mesh belt 46 and the suction unit (suction mechanism) 48 of the selection unit 40, classification is performed. The part 30 may be omitted. In that case, the defibrated material defibrated by the defibrating unit 20 is introduced into the selecting unit 40.

1.3. The additive supplied from the composite additive supply unit 52 contains a resin for binding a plurality of fibers. When the resin is supplied, the plurality of fibers are not bound. The resin melts when passing through the sheet forming unit 80 and binds the plurality of fibers.

  In the present embodiment, the additive supplied from the additive supply unit 52 is a composite (particle) in which at least a part of the surface of the resin particle is covered with the inorganic fine particles. The complex may be used alone or in admixture with another substance as appropriate.

  The composite of the present embodiment is supplied from the additive supply unit 52, and undergoes a triboelectric charging action when passing through the mixing unit 50 and the deposition unit 60. Then, the charged composite adheres to the fibers and is also deposited on the mesh belt 72 together with the fibers and adheres (electrostatically adsorbs) to the fibers even when the web W is formed.

  The absolute value of the average charge amount of the composite of the present embodiment is 40 μC / g or more. The higher the absolute value of the average charge amount of the composite, the stronger or more the composite can be attached to the fiber, so that the composite is preferably 60 μC / g or more, more preferably 70 μC / g or more, further preferably 80 μC / g. g or more, particularly preferably 85 μC / g or more.

The charge amount of such a composite can be measured by frictionally charging the composites. The charge amount can be measured, for example, by stirring (mixing) a powder called a standard carrier and the composite in air and measuring the charge amount of the powder. The standard carrier is, for example, a spherical carrier surface-treated with a ferrite core, which can be purchased from the Imaging Society of Japan (standard carrier for positively charged polar or negatively charged polar toner, available as “P-01 or N-01”). Standard carriers for positively charged polar toners or negatively charged polar toners, ferrite carriers available from Powder Tech Co., Ltd., and the like can be used.

  More specifically, the absolute value of the average charge amount of the composite can be obtained as follows, for example. 80% by mass of the above carrier and 20% by mass of the complex were put into an acrylic container, the container was placed on a ball mill stand at 100 rpm for 60 seconds, and the container was rotated. ) Is mixed. The absolute value [| μC / g |] of the average charge amount is obtained by measuring the mixture of the mixed complex and the carrier with a suction type small charge amount measuring device (for example, Model 210HS-2 manufactured by Trek). be able to.

  Since the absolute value of the average charge amount of the composite is 40 μC / g or more, the charged composite adheres to the fibers and is also deposited on the mesh belt 72 together with the fibers, and the fibers become fibers even when the web W is formed. Can be attached to (electrostatically adsorbed). Such a composite body of the present embodiment is realized by the structure, material and the like described in the following paragraphs.

  The particle size of the particles of the composite (average particle size based on volume) is preferably 50 μm or less, more preferably 30 μm or less, further preferably 25 μm or less, and particularly preferably 20 μm or less. When the average particle size is small, the gravity acting on the composite becomes small, so that the separation from the fibers due to its own weight can be suppressed, and the air resistance becomes small, so that the air flow (wind flow caused by the suction mechanism 76, etc. It is possible to suppress the desorption between the fibers due to) and the desorption due to mechanical vibration. When the composite has a particle size within the above range, the average charge amount of 40 μC / g or more can sufficiently prevent the composite from being detached from the fiber.

  The mesh opening of the mesh belt 72 can be set as appropriate, but since the composite is attached to the fibers, the particle size of the composite is smaller than that of the mesh belt 72 (the size of the hole through which the object passes). Even when the size is small, passage through the mesh belt 72 is suppressed. That is, the composite of the present embodiment has a more remarkable effect when the particle size of the composite is smaller than the mesh opening of the mesh belt 72.

  The lower limit of the average particle size of the particles of the composite is not particularly limited and is, for example, 10 μm, and is arbitrary within a range that can be pulverized by a method such as pulverization. Further, the average particle size of the particles of the composite may have a distribution, and as long as the resin and the inorganic fine particles are integrated, the above-described effect of suppressing desorption from between fibers can be obtained.

  The volume average particle diameter of the particles of the composite can be measured by, for example, a particle size distribution measuring device having a laser diffraction scattering method as a measurement principle. Examples of the particle size distribution measuring device include a particle size distribution meter (for example, “Microtrac UPA” manufactured by Nikkiso Co., Ltd.) having a dynamic light scattering method as a measurement principle.

  The complex may contain other components. Other components include, for example, organic solvents, surfactants, fungicides / preservatives, antioxidants / ultraviolet absorbers, oxygen absorbers and the like.

1.3.1. Structure of Composite In the composite, at least a part of the surface of the resin particles is covered with the inorganic fine particles, and the resin particles or the inorganic fine particles from the composite are provided in the sheet manufacturing apparatus 100 and / or the web W. The inside and the sheet S are in a state of being difficult to separate (hard to separate). That is, the state in which the inorganic particles cover at least a part of the surface of the resin particles means a state in which the resin and the inorganic particles are kneaded, a state in which the inorganic particles are attached or adhered to the surface of the resin particles, a surface of the resin particles. Means that the inorganic fine particles are structurally (mechanically) fixed, and that the resin particles and the inorganic fine particles are aggregated by electrostatic force, van der Waals force, etc., in at least one state. . The state in which at least a part of the surface of the resin particles is covered with the inorganic fine particles may be a state in which the inorganic fine particles are included in the resin particles or a state in which the inorganic fine particles are attached to the resin. Further, it may be a state in which those states exist at the same time. In the present specification, a state in which at least a part of the surface of the resin particles is covered with the inorganic fine particles may be referred to as a state in which the resin and the inorganic fine particles are integrally provided.

  FIG. 2 schematically shows some aspects of a cross section of a composite body that integrally has a resin and inorganic fine particles. As an example of a specific embodiment of a composite having a resin and a wax integrally, for example, as shown in FIG. 2A, a resin re is a state in which inorganic fine particles in are kneaded and dispersed, and at least A complex co in which some of the inorganic fine particles in are exposed on the surface of the complex co can be mentioned.

  Further, as shown in FIG. 2B, the inorganic fine particles in may be arranged so as to cover the surface of the resin re. That is, as an example of a specific embodiment of a composite having a resin and a wax integrally, as shown in FIG. 2B, the inorganic fine particles in are embedded, adhered, and / or attached to the surface of the resin re. And the complex co prepared. The adhesion and / or attachment of both components in this example may be based on electrostatic forces, van der Waals forces, etc.

  In the structure of the complex co shown in FIG. 2, the inorganic fine particles in cover a part of the surface of the resin re particles, but may cover the entire surface of the resin re particles or the resin re particles. The surface of may be multiply covered. Further, a structure in which the structure shown in FIG. 2A and the structure shown in FIG. 2B are combined may be used.

  Further, in the example of FIG. 2, the outer shape of the composite and the outer shape of the inorganic fine particles are both shown to be substantially spherical, but the outer shape of the composite and the inorganic fine particle are not particularly limited, and the disk shape is not limited. It may have a shape such as a shape, a needle shape, or an amorphous shape. However, it is more preferable that the shape of the composite is as close to a spherical shape as possible because it is easily arranged between the fibers in the mixing section 50.

  Further, the composite having any structure shown in FIG. 2 is unlikely to be divided into the resin and the inorganic fine particles during the mixing in the mixing section 50. In the present application, when the composite is not divided into the resin and the inorganic fine particles, it is desirable that the composite is not divided into the total number of composite particles in the powder, but the composite is not actually divided. It's difficult to get into a state. Therefore, the undivided state means that 70% or more of the composite particles on average with respect to the total number of composite particles in the powder are not separated into the resin and the inorganic fine particles.

The structure of the complex co as shown in FIGS. 2A and 2B can be confirmed by various analysis means such as a structural analysis method such as an electron microscope. Whether or not the resin particles are coated with the inorganic fine particles can be evaluated by, for example, measuring the angle of repose. The angle of repose can be measured, for example, according to the method of “Alumina powder? Part 2: Physical property measurement method-2: angle of repose” of JIS R 9301-2-2: 1999. It can be confirmed that the angle of repose becomes smaller in the composite in which the inorganic fine particles are coated with respect to the resin particles in which the inorganic fine particles are not coated.

1.3.2. Functions of Composites Some embodiments of the composite integrally including the resin and the inorganic fine particles have been illustrated, but in any of the embodiments, when various treatments are performed in the sheet manufacturing apparatus 100, the web W, When molded into the sheet S, the resin and the inorganic fine particles are difficult to separate, and the composite adsorbed on the fiber is hard to be detached from the fiber.

  The inorganic fine particles have a function of improving the charge amount of the resin particles (composite) when the inorganic fine particles are arranged on the surface of the resin particles, as compared with the case where the inorganic fine particles are not provided. As the inorganic fine particles, various kinds can be used, but in the sheet manufacturing apparatus 100 of the present embodiment, since water is not used or scarcely used, the kind is disposed on the surface of the composite (a coating may be used). It is preferable to use those of

  The inorganic fine particles increase the chargeability of the composite to generate an adsorbing force (adhesive force) between the composite and the fiber. Therefore, when the web W is deposited on the mesh belt 72 of the second web forming unit 70 of the sheet manufacturing apparatus 100, it is possible to make it difficult for the composite to be detached from between the fibers. Thereby, the mechanical strength of the sheet S manufactured by the sheet manufacturing apparatus 100 can be easily made to be a predetermined value. That is, the composite of the present embodiment has a sufficient adhesive force (electrostatic binding force) to the fibers when arranged between the fibers, and thus is unlikely to separate from the fibers. Regarding the cause of obtaining such an effect, by disposing the inorganic fine particles on the surface of the resin particles, the particles are more easily triboelectrically charged, and the composite is mixed with the fibers in the atmosphere in the mixing section 50, It is thought that this is because static electricity is generated by friction and has an action of attaching the composite (resin) to the fiber.

1.3.3. The material of the composite The type of resin (component of resin particles) that is a component of the composite has already been described, but it is a thermoplastic resin or a thermosetting resin, and examples thereof include AS resin, ABS resin, polypropylene, polyethylene, Polyvinyl chloride, polystyrene, acrylic resin, polyester resin, polyethylene terephthalate, polyphenylene ether, polybutylene terephthalate, nylon, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, polyether ether ketone, and the like. You may use these resins individually or in mixture as appropriate.

  More specifically, the type of resin (component of resin particles) that is a component of the composite may be either a natural resin or a synthetic resin, and may be a thermoplastic resin or a thermosetting resin. In the sheet manufacturing apparatus 100 of the present embodiment, the resin forming the composite is preferably solid at room temperature, and the thermoplastic resin is more preferable in view of binding the fibers by the heat in the sheet forming unit 80. .

  Examples of the natural resin include rosin, dammal, mastic, copal, amber, shellac, kylin blood, sundalac, colophonium, and the like, which may be used alone or in an appropriate mixture, and may be appropriately modified. Good.

  Among the synthetic resins, examples of the thermosetting resin include thermosetting resins such as phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, and thermosetting polyimide resin.

  As the thermoplastic resin among the synthetic resins, AS resin, ABS resin, polypropylene, polyethylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, polyethylene terephthalate, polyphenylene ether, polybutylene terephthalate, nylon, polyamide, polycarbonate, Examples thereof include polyacetal, polyphenylene sulfide, polyether ether ketone, and the like.

  Further, it may be subjected to copolymerization or modification, and examples of such resins include styrene resins, acrylic resins, styrene-acrylic copolymer resins, olefin resins, vinyl chloride resins, polyester resins. Examples thereof include resins, polyamide resins, polyurethane resins, polyvinyl alcohol resins, vinyl ether resins, N-vinyl resins, styrene-butadiene resins, and the like.

  On the other hand, examples of the inorganic fine particles include fine particles made of an inorganic substance, and by disposing them on the surface of the resin particles (composite), a very excellent charging effect can be obtained.

  Specific examples of the material of the inorganic fine particles include silica (silicon oxide), titanium oxide, aluminum oxide, zinc oxide, cerium oxide, magnesium oxide, zirconium oxide, strontium titanate, barium titanate, and calcium carbonate. The inorganic fine particles arranged on the surface of the resin particles may be of one kind or of plural kinds.

  The volume-based average (primary) particle diameter (volume average particle diameter) of the inorganic fine particles is not particularly limited, but is 1 nm or more and 100 nm or less, preferably 2 nm or more and 80 nm or less, more preferably 5 nm or more and 50 nm or less, and further preferably 10 nm or more. It is 40 nm or less. Inorganic fine particles are close to the category of so-called nanoparticles, and are generally primary particles because of their small particle size, but even if a plurality of primary particles are combined to form higher-order particles. Good. The inorganic fine particles of the present embodiment have a small particle size, a large surface area ratio per weight, and accordingly a large surface when triboelectrically charged. Therefore, if the particle size of the inorganic fine particles is within the above range, a good charging effect can be obtained. Further, when the particle size of the inorganic fine particles is within the above range, the surface of the composite can be satisfactorily coated, and in this respect also, a sufficient charging effect can be stably imparted.

  The average (primary) particle diameter of the inorganic fine particles can be measured according to a standard method from the relationship between the specific surface area obtained by the BET method and the like and the density.

  When the content of the inorganic fine particles in the composite is 0.01% by mass or more and 10% by mass or less with respect to 100% by mass of the composite, the above effect can be obtained, and the effect is further enhanced, and / or From the standpoint of effectively using the inorganic fine particles (the amount of charge is less likely to increase even if the addition amount increases when the amount of the inorganic fine particles is too large), etc., preferably 0.05 mass with respect to 100 mass% of the composite. % Or more and 5 mass% or less, more preferably 0.1 mass% or more and 4 mass% or less, and further preferably 0.1 mass% or more and 3 mass% or less.

  The method for disposing (coating) the inorganic fine particles on the surface of the composite is not particularly limited, and the inorganic fine particles may be blended with the resin when forming the composite by the above-mentioned melt-kneading or the like. However, in this case, since most of the inorganic fine particles are arranged inside the composite, the charging effect with respect to the added amount of the inorganic fine particles is reduced. In view of the mechanism of charge generation, the inorganic fine particles are more preferably arranged on the surface of the composite as much as possible. Examples of the mode of arranging the inorganic fine particles on the surface of the composite include coating and coating, but the entire surface of the composite does not necessarily have to be covered. The coverage may exceed 100%, but if it is about 300% or more, the action of binding the composite and the fiber may be impaired. Therefore, an appropriate coverage may be selected according to the situation. To do.

Although various methods can be considered as a method for disposing the inorganic fine particles on the surface of the composite, the effect can be achieved by simply mixing the two and adhering them to the surface by electrostatic force or van der Waals force. The concern remains. Therefore, a method in which the composite and the inorganic fine particles are charged into a mixer rotating at high speed and uniformly mixed is preferable. As such a device, a known device can be used, and an FM mixer, a Henschel mixer, a super mixer or the like can be used. Particles of inorganic fine particles can be arranged on the surface of the composite by such a method. The inorganic fine particles arranged by such a method may be arranged in a state in which at least a part thereof erodes the surface of the composite or in a state in which it is embedded, and the inorganic fine particles can be more difficult to drop out from the composite, The charging effect can be stably exhibited. Further, by using such a method, the above arrangement can be easily realized in a system containing little or no water. Even if there are inorganic fine particles that do not bite into the composite, such an effect can be sufficiently obtained. The state in which the inorganic fine particles invade the surface of the composite or the state in which it is embedded can be confirmed by various electron microscopes.

  A sufficient charging effect can be obtained when the ratio of the inorganic fine particles coated on the surface of the composite (area ratio: this may be referred to as a coverage in this specification) is 20% or more and 100% or less. . The coverage can be adjusted by charging a device such as an FM mixer. Further, if the specific surface area of the inorganic fine particles and the composite is known, it can be adjusted by the mass (weight) of each component at the time of charging. The coverage can also be measured with various electron microscopes. It should be noted that when the inorganic fine particles are arranged in such a manner that they do not easily drop out of the composite, it can be said that the inorganic fine particles are integrally contained in the composite.

  Further, the inorganic fine particles may be surface-modified. Specifically, the surface of the inorganic fine particles may be chemically treated with a silane compound to modify the surface and then used. Examples of such silane compounds include alkylsilanes such as trimethylsilane, dimethylsilane, triethylsilane, triisopropylsilane, and triisobutylsilane, and silane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane. it can.

  Since the composite has the inorganic fine particles, the composite easily adheres electrostatically to the fibers, and it is possible to prevent the composite from coming off from the fiber and from coming off from the web and the sheet. Also, the composite and the fibers can be mixed very well by air flow or stirring by a mixer. The reason is that when the inorganic fine particles are arranged on the surface of the composite, the composite tends to be charged with static electricity, and the static electricity makes the composite easily attached to the fiber. Further, the composite adhered to the fibers due to the static electricity does not easily detach from the fibers even when a mechanical shock or the like occurs. Therefore, even if no special means other than the mixing of the fiber and the composite is used, the fibers are quickly mixed and the dropout is sufficiently suppressed. Further, after the mixture was formed, the adhesion of the composite to the fiber was stable, and the phenomenon of desorption of the composite was not observed.

  It is considered that the composite particles are more strongly attached to the fibers by the electrostatic force than the case where the particles are made of the resin alone. Further, it has been found that the effect of the inorganic fine particles is not impaired even when the resin particles contain a pigment. Furthermore, in general, static electricity is less likely to accumulate when the humidity is high, but for example, even if some moisture is contained in the case where the fiber is cellulose, the adhesion of the composite to the fiber is improved by the presence of the inorganic fine particles.

1.3.5. Other components In addition, it is stated that the composite may contain a colorant for coloring the fibers and a flame retardant for making the fibers difficult to burn, but in the case of containing at least one of these, Can be more easily obtained by blending these with a resin by melt-kneading. The inorganic fine particles can be blended by forming such a resin powder and then mixing the resin powder and the inorganic fine particle powder with a high-speed mixer or the like.

The fibers and the composite are mixed in the mixing section 50, and the mixing ratio thereof can be appropriately adjusted depending on the strength of the sheet S to be manufactured, the application, and the like. When the produced sheet S is for office use such as copy paper, the ratio of the composite to the fiber is 5% by mass or more and 70% by mass or less, and the viewpoint of obtaining good mixing in the mixing section 50, and the mixture sheet From the viewpoint of making it more difficult for the composite to be detached by gravity when molded into a shape, the content is preferably 5% by mass or more and 50% by mass or less.

1.4. Mixing Unit The mixing unit 50 provided in the sheet manufacturing apparatus 100 of the present embodiment has a function of mixing the fiber and the composite. In the mixing section 50, at least the fiber and the composite are mixed. In the mixing section 50, components other than the fiber and the composite may be mixed. As used herein, "mixing fibers and composites" is defined as positioning the composites between fibers in a space (system) of constant volume.

  The mixing process in the mixing section 50 of the present embodiment is a method (dry method) of introducing the fibers and the composite into the air flow and diffusing them into each other in the air flow, and is a hydrodynamic mixing process. The "dry type" in mixing means a state of mixing in air rather than in water. That is, the mixing unit 50 may function in a dry state, or may function in a state in which a liquid existing as an impurity or a liquid intentionally added exists. When the liquid is intentionally added, it is preferable to add the liquid in a subsequent step to such an extent that energy or time for removing the liquid by heating or the like does not become too large. In the case of such a method, it is more preferable that the air flow in the pipe 54 or the like is a turbulent flow because the mixing efficiency may be improved.

  The processing capacity of the mixing unit 50 is not particularly limited as long as the fibers (fiber material) and the composite can be mixed, and can be appropriately designed and adjusted according to the manufacturing capacity (throughput) of the sheet manufacturing apparatus 100. . The processing capacity of the mixing section 50 can be adjusted by changing the flow rate of gas for transferring the fibers and the composite in the tube 54, the amount of material introduced, the amount of material transferred, and the like.

  The mixture mixed by the mixing unit 50 may be further mixed by another configuration such as a sheet forming unit. Further, in the example of FIG. 1, the mixing section 50 has the blower 56 provided in the tube 54, but may further have a blower not shown.

  The blower is a mechanism for mixing the fibers and the composite, and has a rotating portion having rotating blades. The rotation of such blades causes the fibers and / or composites to be rubbed by or impinged on the blades. Further, when the blade rotates, the airflow formed by the blade causes the fibers to come into contact with each other, the fibers to the composite, and / or the composite to come into friction with each other.

  It is considered that such a collision or a friction causes at least the composite to be charged (charged with static electricity), and an adhesive force (electrostatic force) for attaching the composite to the fiber is generated. The strength of such adhesion depends on the properties of the fiber and the composite, and the structure of the blower (the shape of the rotating blade, etc.). Even if one blower 56 is provided as shown in FIG. 1, a sufficient adhesive force can be obtained, but by providing another blower on the downstream side of the additive supply unit 52, a stronger adhesive force can be obtained. May be able to get. The number of blowers to be added is not particularly limited. Further, when a plurality of blowers are provided, a main function may be shared by each blower, for example, by providing a blower having a large air supply force and a blower having a larger stirring force (chargeability). In this case, the adhesion of the composite to the fibers may be increased in some cases, and the detachment of the composite from the fibers can be further suppressed when the web W is formed.

1.5. In the sheet manufacturing apparatus 100 of the present embodiment, when the composite material mixed with the fibers in the mixing section 50 is the one in which the inorganic particles cover at least a part of the surface of the resin particles, the web is formed. , The composite is difficult to detach from between the fibers. Then, since the composite and the fibers are bound in the sheet forming unit 80, it is possible to manufacture a sheet having good resin dispersibility and good uniformity in strength and the like.

  The composite used in the sheet manufacturing apparatus 100 of the present embodiment has a very excellent adhesive force with fibers. The inorganic particles are added to the resin as a unit, and due to the property of the inorganic particles to be easily charged with static electricity, the composite particles tend to be charged with static electricity, resulting in an increase in the charge amount of the composite and adhesion to the fiber. Is improved.

  Further, the sheet manufacturing apparatus of the present embodiment has a mesh belt 72 that forms the web W and a suction mechanism 76 in the second web forming unit 70, and the suction mechanism 76 interposes the mesh belt 72. It can be said to be a suction unit that sucks the mixture discharged by the deposition unit 60. Such a suction unit sucks the deposit through the mesh belt to increase the possibility that the composite is detached from the fiber. However, according to the sheet manufacturing apparatus of the present embodiment, the suction unit is provided. Nevertheless, the detachment of the composite from the fiber can be sufficiently suppressed.

2. Sheet production method The sheet production method of the present embodiment is a mixture of fibers, a composite of resin and inorganic fine particles integrated in air, and a mixture of the fibers and the composite. Depositing, heating and shaping. The fibers, resins, inorganic fine particles, and composites are the same as those described in the above-mentioned sheet manufacturing apparatus, so detailed description will be omitted.

  The sheet manufacturing method of the present embodiment includes a step of cutting a pulp sheet or a waste paper as a raw material in the air, a defibrating step of unraveling the raw material into a fibrous state in the air, and impurities (toner or toner from the defibrated defibrated material). Classifying process of classifying fibers shortened by paper strength enhancer or defibration (short fibers) in air, long fibers (long fibers) or undefibrated pieces that have not been sufficiently defibrated from the defibrated material to air A sorting step of sorting in, a dispersing step of dispersing the mixture while dispersing it in the air, a molding step of depositing the descending mixture in the air to form a web shape, and a drying step of drying the sheet if necessary. It may include at least one step selected from the group consisting of a winding step of winding the formed sheet into a roll, a cutting step of cutting the formed sheet, and a packaging step of packaging the manufactured sheet. . Since the details of these steps are the same as those described in the section of the sheet manufacturing apparatus, detailed description thereof will be omitted.

3. Sheet The sheet S manufactured by the sheet manufacturing apparatus 100 or the sheet manufacturing method of the present embodiment mainly refers to a sheet formed from at least the above fiber as a raw material. However, the shape is not limited to the sheet shape, and may be a board shape, a web shape, or a shape having irregularities. The sheet in this specification can be classified into paper and non-woven fabric. The paper includes, for example, a mode in which a pulp or waste paper is used as a raw material and formed into a sheet shape, and includes recording paper for the purpose of writing and printing, wallpaper, wrapping paper, colored paper, drawing paper, Kent paper, and the like. Nonwoven fabrics are thicker than paper and have low strength, and include general non-woven fabrics, fiber boards, tissue papers, kitchen papers, cleaners, filters, liquid absorbents, sound absorbers, cushioning materials, mats, and the like.

  In the case of a non-woven fabric, the distance between the fibers is wide (the density of the sheet is small). In contrast, paper has a narrow fiber-to-fiber spacing (high sheet density). Therefore, when the sheet S manufactured by the sheet manufacturing apparatus 100 of the present embodiment or the sheet manufacturing method is paper, it is possible to suppress the detachment of the composite from the fibers and to obtain an effect such as strength uniformity when formed into a sheet. , The function can be more remarkably expressed.

4. Storage Container The storage container of the present embodiment is used by being mixed with fibers and stores the above-described composite body in which a resin and inorganic fine particles are integrated.

  The composite of the present embodiment is supplied to the mixing section 50 by opening and closing a feeder and a valve. The composite of the present embodiment is supplied in a powder state in appearance. Therefore, for example, after the composite is manufactured, the device can be configured to be directly supplied to the mixing unit 50 through a pipe or the like. However, depending on the installation location of the device, the composite may be put on the distribution channel as a product, and the composite may be transported or stored after being manufactured.

  The storage container of the present embodiment has a storage chamber that stores the complex, and the complex can be stored in the storage chamber. That is, the container of the present embodiment can be called a complex cartridge, and the complex can be easily transported and stored.

  The shape of the storage container is not particularly limited, and may be the shape of a cartridge suitable for the sheet manufacturing apparatus 100. The accommodating container can be formed of, for example, a general polymer material. Further, the storage container may have a box-like rigid form or a film (bag) -like flexible form. The material forming the container is preferably a material having a higher glass transition temperature or melting point than the material of the complex to be contained.

  The accommodation chamber for accommodating the complex is not particularly limited as long as it can accommodate and retain the complex. The storage chamber can be formed of a film, a molded body, or the like. When the accommodating chamber is formed of a film, the accommodating container may be formed to include a molded body (housing) that accommodates the film forming the accommodating chamber. Further, the accommodation chamber may be formed by a relatively robust molded body.

  The film or molded body forming the storage chamber is composed of a polymer, a metal vapor deposition film, or the like, and may have a multilayer structure. When the storage container is formed of a plurality of members such as a film or a molded body, a welded portion or an adhesive portion may be formed. Further, when the contained complex (powder) is affected by alteration or the like due to contact with the atmosphere, the film or molded body is preferably formed of a material having a low gas permeability. Among the materials of the film and the molded body forming the accommodation chamber, the material of the portion in contact with the accommodated complex is preferably stable with respect to the complex.

  The shape and volume of the storage chamber are not particularly limited. Although the complex is accommodated in the accommodating chamber, a solid or gas inert to the complex may be accommodated together with the complex. The volume of the complex housed in the housing chamber is also not particularly limited.

  The accommodating chamber may have a flow port that allows the inside of the accommodating chamber to communicate with the outside of the accommodating container and allows the complex to be taken out of the accommodating container. Further, in the storage chamber, a flow passage other than the circulation port may be formed. As such another flow passage, for example, an open valve or the like may be used. When the release valve is provided in the storage chamber, the position where the release valve is placed is not particularly limited, but it is placed on the opposite side to the direction in which gravity acts in the normal posture during transfer, transportation and use. In some cases, when pressure or the like is generated in the storage chamber, it is difficult to discharge the composite when releasing the pressure to the atmosphere, which is preferable.

5. Other matters As described above, the sheet manufacturing apparatus and the sheet manufacturing method of the present embodiment use water at all or only slightly, but if necessary, by spraying or the like, as appropriate for the purpose of humidity control or the like. It is also possible to add water to produce the sheet.

  As water in such a case, it is preferable to use pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water. In particular, water obtained by sterilizing these waters by irradiating ultraviolet rays or adding hydrogen peroxide is preferable because it can suppress the generation of mold and bacteria for a long period of time.

  In the present specification, the term “homogeneous” means the relative presence of one component with respect to another component in an object in which two or more components or two or more components can be defined, in the case of homogeneous dispersion and mixing. The positions are uniform throughout the system or the same or substantially equal to each other in each part of the system. Further, the uniformity of coloring and the uniformity of color tone indicate that the sheet has a uniform density with no shade when the sheet is viewed in a plan view.

  In the present specification, terms such as “uniform”, “same”, “equal spacing”, etc. are used which mean that density, distance, size, etc. are equal. It is desirable that they are equal, but it is difficult to make them completely equal. Therefore, it is assumed that the values do not become equal due to the accumulation of errors and variations, and deviate.

6. Experimental Examples The present invention will be further described below with reference to experimental examples, but the present invention is not limited to the following examples.

6.1. Preparation of composite (1) Styrene maleic acid resin (Tg: 74 ° C, molecular weight 6600): 1.5 kg
(2) Polyester resin (Tg: 56 ° C., molecular weight 10000): 8.0 kg
(3) Copper phthalocyanine pigment (PigmentGreen36): 0.5 kg
After the above materials were mixed in the hopper, they were put into a twin-screw kneading extruder and melt-kneaded at 90 ° C to 135 ° C. It was extruded with a die into a strand and cut into a length of about 5 mm to obtain a pellet.

  The pellets obtained above were treated with a high speed mill for 30 seconds to coarsely crush the pellets into granules, which were then put into a jet mill to obtain a powder having a particle size range of 1 μm to 40 μm.

  The powder obtained by the jet mill was subjected to a classifier to obtain powder resin particles (A1) composed of particles having a volume-based average particle diameter of 12 μm and a particle diameter range of 5 μm to 23 μm.

6.2. Experimental example 1
(1) Resin particles (A1): 100 g
(2) Inorganic fine particles (M1): 1.5 g
The inorganic fine particles (M1) were coated on the surface of the resin particles (A1) by introducing the above materials into a desktop blender and stirring at a blade tip speed of 30 m / s for 80 seconds. The presence or absence of coating was confirmed by observing the particle surface by SEM. Furthermore, confirmation was made by changing the angle of repose. This was judged from the fact that the angle of repose decreases when a coating (coating with inorganic fine particles) is formed. As the inorganic fine particles (M1), titanium dioxide having a volume-primary particle size of 14 nm whose surface was hydrophobized with alkylsilane was used.

6.3. Experimental example 2
Fine particles of silicon dioxide having a volume-based primary particle diameter of 12 nm whose surface is modified with trimethylsilane are used as inorganic fine particles (M2). The procedure was the same as in Experimental Example 1 except that the inorganic fine particles (M2) were used instead of the inorganic fine particles (M1) used in Experimental Example 1.

6.4. Experimental example 3
Fine particles of silicon dioxide having a volume-based primary particle diameter of 20 nm whose surface is modified with trimethylsilane are used as inorganic fine particles (M3). The procedure was the same as in Experimental Example 1 except that the inorganic fine particles (M3) were used instead of the inorganic fine particles (M1) used in Experimental Example 1.

6.5. Experimental example 4
Fine particles of silicon dioxide having a volume-based primary particle diameter of 20 nm, the surface of which has been modified with trimethylsilane, are referred to as inorganic fine particles (M4). The procedure was the same as in Experimental Example 1 except that the inorganic fine particles (M4) were used instead of the inorganic fine particles (M1) used in Experimental Example 1.

6.6. Experimental example 5
Resin particles (A1) having no surface coated were used.

6.7. Measurement of charge amount (1) Standard carrier N-01 (obtained from Japan Imaging Society): 4.85 g
(2) Powder of each experimental example (composite or resin particle): 0.15 g
The above was weighed and put into an acrylic container, the container was placed on a ball mill stand at 100 rpm1 for 180 seconds, and the container was rotated to mix the carrier and particles (powder). The absolute value [| [mu] C / g |] of the average charge amount of the mixed powder and carrier mixture was calculated by a suction type small charge amount measuring device (Model 210HS-2, manufactured by Trek) and listed in Table 1.

6.8. Evaluation of retention rate of particles to fibers (1) Bleached softwood kraft pulp (NBKP): 16 g
(2) Composite particles (Experimental Examples 1 to 4) or resin particles (Experimental Example 5): 4 g
(3) Particle content rate: 4 g / (16 g + 4 g) = 20% by mass
The above mass is weighed and put in a transparent polyethylene bag of 520 mm x 600 mm x 0.030 mm, air is blown in with an air gun, and the pulp and the composite or resin particles are agitated with an air flow to produce pulp and composite or pulp and resin. A mixture of particles (powder of each experimental example) was mixed.

  5.0 g of the mixture of each experimental example was taken out and gently spread evenly on a 140-mesh standard sieve with tweezers. Then, the same sieve was covered on the upper side of the sieve and set on the suction device. FIG. 3 shows a schematic diagram of the suction device 200. The suction device 200 used is self-made, and has a configuration as shown in FIG. 3, and includes a funnel-shaped funnel portion 220 for setting the sieve 210, an exhaust device 230, and an exhaust filter 240. In this device, when the sieve 210 on which nothing was placed was installed, the exhaust speed of the exhaust device 230 was adjusted so that the wind speed on the mesh surface of the sieve 210 was 25 ± 1 m / s. It should be noted that the form of the device does not necessarily have to be as shown in FIG. 3 as long as this wind speed condition is satisfied. The sieve 210 was set in the suction device 200 in a state where each mixture was sandwiched by the sieve 210, suction was performed for 30 seconds, and the value when the mass of each remaining mixture was measured was defined as X (g). .

Here, the particle retention rate RV (%) is
RV = (5 × 0.2− (5-X)) / (5 × 0.2) × 100 = (X−4) × 100
It is calculated according to the following formula. The higher the particle retention rate is, the more the mixture is held between the fibers of the pulp. If RV = 100%, the particles of the mixture do not pass through the sieve 210 by suction, which is an ideal state. I can say. The particle retention rate of each experimental example is shown in Table 1.

  In each experimental example, the weight of the mixture sandwiched between the sieves 210 was 5.0 g, but this mass may be appropriately adjusted depending on the test efficiency and the like. However, in each sieve 210 used in the measurement, a mixture having a volume capable of covering the entire surface of the sieve is sandwiched. When the mass of the mixture satisfying this condition is selected, the obtained RV value tends to be independent of the mass of the mixture.

6.9. Evaluation Results Table 1 summarizes the properties of the samples and the particle retention rate for each experimental example.

  As shown in Table 1 above, it was found that the charge amount of the obtained powder can be controlled by changing the coating state of the resin particles with the inorganic fine particles. It was also found that the particle retention rate on pulp fibers can be controlled by controlling the charge amount. The larger the charge amount of the particles (composite), the higher the particle retention rate tends to be. The higher particle retention means that the resin particles of the composite adhere firmly to the pulp fibers (cellulose), and It is considered to be in a state of not being detached.

  Further, from Table 1, it was found that when the absolute value of the average charge amount is 40 μC / g or more, the particle retention rate becomes about 80% or more, which is a level that does not hinder actual sheet production. . Further, it was found that when the absolute value of the average charge amount is 80 μC / g or more, the particle retention rate becomes 95% or more, and the detachment of the resin particles (composite) from the fiber is very small, which is even better. .

  When the composite having the charge amount in the range as in Experimental Examples 1 to 4 is used, it is difficult for the resin component to be detached from the fiber when the sheet is manufactured by the dry method, and as a result, the tough sheet as designed is manufactured. It turned out to be possible.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (configurations that have the same functions, methods and results, or configurations that have the same objects and effects). Further, the invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. In addition, the invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes configurations in which known techniques are added to the configurations described in the embodiments.

1 ... Hopper, 2, 3, 4, 5 ... Tube, 6 ... Hopper, 7, 8 ... Tube, 9 ... Hopper, 10 ... Supply section, 12 ... Coarse crushing section, 14 ... Coarse crushing blade, 20 ... Disentangle section , 22 ... Inlet port, 24 ... Outlet port, 30 ... Classifying part, 31 ... Inlet port, 32 ... Cylindrical part, 33 ... Inverse conical part, 34 ... Lower outlet port, 35 ... Upper outlet port, 36 ... Receiving part, 40 ... Sorting unit, 42 ... Inlet port, 44 ... Discharge port, 45 ... First web forming unit, 46 ... Mesh belt, 47 ... Stretching roller, 48 ... Suction unit, 50 ... Mixing unit, 52 ... Additive supply unit, 54 ... Tube, 56 ... Blower, 60 ... Accumulation part, 62 ... Inlet port, 70 ... Second web forming part, 72 ... Mesh belt, 74 ... Stretching roller, 76 ... Suction mechanism, 78 ... Humidity adjusting part, 80 ... Sheet forming portion, 82 ... First binding portion, 84 ... Second binding portion, 86 ... Heating roller, 87a, 87 ... Cooling roller, 90 ... Cutting section, 92 ... First cutting section, 94 ... Second cutting section, 96 ... Ejection section, 100 ... Sheet manufacturing apparatus, 102 ... Manufacturing section, 140 ... Control section, S ... Sheet, V ... Web, W ... Web, re ... Resin, in ... Inorganic fine particles, co ... Composite, 200 ... Suction device, 210 ... Sieve, 220 ... Funnel part, 230 ... Exhaust device, 240 ... Exhaust filter

Claims (6)

A composite which is mixed with fibers to bind a plurality of said fibers together,
The composite is a resin particle in which at least a part of the surface is coated with inorganic fine particles,
Absolute value of the average charge quantity of the conjugate state, and are 75 [mu] C / g or more,
The absolute value of the average charge amount, were mixed and the standard carrier, and the complex, and wherein the value der Rukoto measured by the suction type small charge measuring device, complex.   The composite according to claim 1, wherein the volume-based average particle diameter of the resin particles is 25 μm or less.   The volume-based average particle size of the inorganic fine particles is 40 nm or less, and the composite according to claim 1 or claim 2.   The composite according to any one of claims 1 to 3, wherein a component of the resin particles is a thermoplastic resin or a thermosetting resin.   The composite material according to any one of claims 1 to 4, wherein the material of the inorganic fine particles is silica.   Content of the said inorganic fine particle in the said composite_body is 0.1 mass% or more and less than 4 mass%, The composite_body | complex of any one of Claim 1 thru | or 5 characterized by the above-mentioned.

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