JP5029389B2 - Resin dispersion continuous coagulation method - Google Patents

Description

  The present invention relates to a method for producing a resin coagulated granule having a size within a predetermined range by continuously coagulating a resin dispersion such as an emulsion or a suspension.

  When a resin component is taken out from a resin dispersion such as a fluorine-containing elastomer aqueous dispersion, a coagulation method in which a coagulation liquid is added to the resin dispersion and a shearing force is applied is generally employed. Such a coagulation method includes a batch method and a continuous method, and the continuous method is preferable in terms of excellent productivity. As a continuous method, for example, “a continuous coagulation method in which a rubber latex and a coagulation liquid are continuously supplied into a coagulation apparatus to coagulate the rubber latex continuously” has been proposed (for example, , See Patent Document 1).

In addition, in the past, “a process of continuously supplying a polytetrafluoroethylene aqueous dispersion to a high shearing device to form a slurry, and continuously supplying the slurry to a vertical agitator from below to granulate with stirring. And a method for continuously producing a wet powder of polytetrafluoroethylene comprising a step of taking out the wet powder from above and a step of discharging the wet powder onto a belt conveyor of a wire mesh and separating it from water (for example, , See Patent Document 2).
JP-A-57-14639 JP-A-2-239911

  However, when these methods are used, there are problems that a large amount of unaggregated components remain and wastewater treatment is required, that the particle size of the agglomerated particles is difficult to control, and that quality control is difficult. There was a problem that the processing time in the latter vertical stirrer was long and the productivity was lowered. Further, when the method of Patent Document 2 is applied to a fluorine-containing elastomer, there arises a problem that drainage is insufficient due to adhesion to the belt of the metal mesh due to the adhesion of the elastomer particles.

  An object of the present invention is to provide a resin dispersion continuous coagulation method that can completely coagulate the resin in the resin dispersion in a short time and can easily control the particle diameter of the coagulated particles obtained. It is to provide.

The resin dispersion continuous coagulation method according to the first invention includes a first shearing step and a second shearing step. In the first shearing step, a first shearing force is applied to the resin dispersion or the coagulated resin dispersion. As used herein, the term "resin dispersion" is the aqueous fluoroelastomer dispersion. In addition, a coagulation liquid may be required to coagulate the resin dispersion. In the second shearing step, a shearing force different from the first shearing force (hereinafter referred to as “first shearing force”) is applied to the coagulated resin dispersion produced from the resin dispersion in the first shearing step or the coagulated resin dispersion obtained through the first shearing step. 2 shear force) is applied. Note that a plurality of shearing steps may be provided after the second shearing step. The first shearing step is performed by a pipeline mixer (1A) driven by a first driving source, and the second shearing step is driven by a second driving source provided independently of the first driving source. It is carried out by a pipeline mixer (1B). The rotational speed of the drive shaft of the pipeline mixer (1B) is set higher than the rotational speed of the drive shaft of the pipeline mixer (1A).

  In this resin dispersion continuous coagulation method, after the first shearing force is applied to the resin dispersion in the first shearing step, the coagulated resin dispersion generated from the resin dispersion in the first shearing step in the second shearing step. A second shear force is applied to the liquid. Therefore, in this resin dispersion continuous coagulation method, a strong shear force is applied to the resin dispersion in the first shearing step to complete the coagulation of the resin dispersion in a short time, and a stronger shearing force is applied in the second shearing step. It is possible to coagulate unaggregated matter by applying. Therefore, by using this resin dispersion continuous coagulation method, it is possible to shorten the coagulation time from the resin dispersion and improve the removal rate of uncoagulated components. Further, in this resin dispersion continuous coagulation method, the resin dispersion is coagulated by applying a relatively weak shear force to the resin dispersion in the first shearing step so as to obtain coagulated particles having a particle diameter within a predetermined range. In the second shearing step, the uncoagulated component can be coagulated by applying a stronger shearing force than in the first shearing step. Therefore, if this resin dispersion continuous coagulation method is used, the particle size of coagulated particles can be easily controlled and the amount of uncoagulated components can be reduced. As a result, if this resin dispersion continuous coagulation method is used, coagulated particles with stable quality can be continuously produced.

  In the latter case, the coagulation efficiency in the first shearing process may be insufficient.

  Further, in this resin dispersion continuous coagulation method, after the first shearing force is applied to the coagulated resin dispersion in the first shearing process, the coagulated resin dispersion that has undergone the first shearing process in the second shearing process is applied. A shear force different from the first shear force is applied to the liquid. For this reason, in this resin dispersion continuous coagulation method, the amount of uncoagulated components is reduced stepwise. Therefore, if this resin dispersion continuous coagulation method is used, the coagulation time can be shortened and the removal rate of uncoagulated components can be improved.

The resin dispersion continuous coagulation method according to the second invention is the resin dispersion continuous coagulation method according to the first invention, and the second coagulation device is the same pipeline mixer as the first coagulation device. The second drive source may be the same drive source as the first drive source or a different drive source.

For this reason, if the 1st coagulation apparatus and the 2nd coagulation apparatus are set so that desired shear force may be applied to the resin dispersion liquid, this resin dispersion continuous coagulation method can be implemented.

The third resin dispersion continuous coagulation析方method according to the invention is a析方method continuous resin dispersion coagulation added stepwise different shearing force to wood fat dispersions, resin dispersion is aqueous fluoroelastomer dispersion The first shearing step is performed by the pipeline mixer (1A) driven by the first driving source, and the second shearing step is driven by the second driving source provided independently of the first driving source. The rotation speed of the drive shaft of the pipeline mixer (1B) is made higher than the rotation speed of the drive shaft of the pipeline mixer (1A).

  For this reason, in this resin dispersion continuous coagulation method, first, a strong shearing force is applied to the resin dispersion in the first stage to complete the coagulation of the resin dispersion in a short time, and further in the stages after the second stage. Uncoagulated components can be coagulated by applying a strong shearing force. Therefore, by using this resin dispersion continuous coagulation method, it is possible to shorten the coagulation time from the resin dispersion and improve the removal rate of uncoagulated components. Further, in this resin dispersion continuous coagulation method, the resin dispersion is coagulated by applying a relatively weak shearing force to the resin dispersion in the first stage so that coagulated particles having a particle diameter within a predetermined range can be obtained. In the second and subsequent stages, the uncoagulated component can be coagulated by applying a stronger shearing force than in the first stage. Therefore, if this resin dispersion continuous coagulation method is used, the particle size of coagulated particles can be easily controlled and the amount of uncoagulated components can be reduced. As a result, if this resin dispersion continuous coagulation method is used, coagulated particles with stable quality can be continuously produced.

  In the latter case, the coagulation efficiency in the first stage may be insufficient.

The resin dispersion continuous coagulation method according to the fourth invention is the resin dispersion continuous coagulation method according to any of the first to third inventions, wherein the pipeline mixers (1A) and (1B) are stirred with the casing. The gap between the casing and the stirring rod is about 5 to 10 mm, the peripheral speed of the stirring rod is in the range of 2 to 20 m / sec, and the pipeline mixers (1A) and (1B) The polymer concentration is 3 to 20% by mass.

  In the resin dispersion continuous coagulation method according to the first invention, after the first shearing force is applied to the resin dispersion in the first shearing step, the coagulation produced from the resin dispersion in the first shearing step in the second shearing step. A second shearing force is applied to the deposited resin dispersion. Therefore, in this resin dispersion continuous coagulation method, a strong shear force is applied to the resin dispersion in the first shearing step to complete the coagulation of the resin dispersion in a short time, and a stronger shearing force is applied in the second shearing step. It is possible to coagulate unaggregated matter by applying. Therefore, by using this resin dispersion continuous coagulation method, it is possible to shorten the coagulation time from the resin dispersion and improve the removal rate of uncoagulated components. Further, in this resin dispersion continuous coagulation method, the resin dispersion is coagulated by applying a relatively weak shear force to the resin dispersion in the first shearing step so as to obtain coagulated particles having a particle diameter within a predetermined range. In the second shearing step, the uncoagulated component can be coagulated by applying a stronger shearing force than in the first shearing step. Therefore, if this resin dispersion continuous coagulation method is used, the particle size of coagulated particles can be easily controlled and the amount of uncoagulated components can be reduced. As a result, if this resin dispersion continuous coagulation method is used, coagulated particles with stable quality can be continuously produced.

  In the latter case, the coagulation efficiency in the first shearing process may be insufficient.

  Further, in this resin dispersion continuous coagulation method, after the first shearing force is applied to the coagulated resin dispersion in the first shearing process, the coagulated resin dispersion that has undergone the first shearing process in the second shearing process is applied. A shear force different from the first shear force is applied to the liquid. For this reason, in this resin dispersion continuous coagulation method, the amount of uncoagulated components is reduced stepwise. Therefore, if this resin dispersion continuous coagulation method is used, the coagulation time can be shortened and the removal rate of uncoagulated components can be improved.

If the first coagulation device and the second coagulation device are set so that a desired shear force is applied to the resin dispersion, the resin dispersion continuous coagulation method according to the first invention can be implemented.

The resin dispersion continuous coagulation method according to the first invention can be carried out only by setting the first drive source and the second drive source so that a desired shearing force is applied to the resin dispersion.

According to the resin dispersion continuous coagulation method according to the second invention, a desired shearing force can be applied to the resin dispersion by adjusting the rotational speed of the mixer. Therefore, if this resin dispersion continuous coagulation method is used, the degree of aggregation of the resin dispersion can be easily controlled.

In the resin dispersion continuous coagulation method according to the third aspect of the invention, first, a strong shearing force is applied to the resin dispersion in the first stage to complete the coagulation of the resin dispersion in a short time, and in the stages after the second stage. Further, a strong shearing force can be applied to coagulate the uncoagulated component. Therefore, by using this resin dispersion continuous coagulation method, it is possible to shorten the coagulation time from the resin dispersion and improve the removal rate of uncoagulated components. Further, in this resin dispersion continuous coagulation method, the resin dispersion is coagulated by applying a relatively weak shearing force to the resin dispersion in the first stage so that coagulated particles having a particle diameter within a predetermined range can be obtained. In the second and subsequent stages, the uncoagulated component can be coagulated by applying a stronger shearing force than in the first stage. Therefore, if this resin dispersion continuous coagulation method is used, the particle size of coagulated particles can be easily controlled and the amount of uncoagulated components can be reduced. As a result, if this resin dispersion continuous coagulation method is used, coagulated particles with stable quality can be continuously produced.

  In the latter case, the coagulation efficiency in the first stage may be insufficient.

<Coagulation target>
In the present embodiment, a fluorine-containing elastomer aqueous dispersion is selected as the resin dispersion to be coagulated. Hereinafter, details of the fluorine-containing elastomer aqueous dispersion will be described.

  As the fluorine-containing elastomer aqueous dispersion to be coagulated, one having a polymer concentration of 5 to 50% with respect to the aqueous dispersion is preferable.

  In the present embodiment, the fluorine-containing elastomer generally has 30 to 80% by mass of copolymerized units of the first monomer. Here, the “first monomer” means a monomer that constitutes a copolymer unit occupying the largest mass among all copolymer units in the molecular structure of the fluorine-containing elastomer. Examples of the first monomer include vinylidene fluoride (hereinafter referred to as “VdF”), tetrafluoroethylene (hereinafter referred to as “TFE”), perfluoro (alkyl vinyl ether) (hereinafter referred to as “PAVE”), hexafluoropropylene ( (Hereinafter referred to as “HFP”).

Moreover, in this embodiment, a copolymerization unit is a part on the molecular structure of a fluorine-containing elastomer, Comprising: The part derived from a corresponding monomer is meant. For example, the VdF unit is a part of the molecular structure of the VdF copolymer and is a part derived from VdF, and is represented by — (CH ₂ —CF ₂ ) —. The “total copolymerized unit” means all the parts derived from the monomer in the molecular structure of the fluorine-containing elastomer. The content of copolymerized units can be obtained by measuring ¹⁹ F-NMR. The fluorine-containing elastomer is one in which the copolymer unit derived from a monomer other than the first monomer is derived from only one of the monomers copolymerizable with the first monomer. Alternatively, it may be derived from two or more monomers copolymerizable with the first monomer. Examples of monomers copolymerizable with the first monomer include fluorine-containing olefins, fluorine-containing vinyl ethers, and hydrocarbon olefins. Further, the fluorine-containing olefin is not particularly limited. For example, VdF, TFE, HFP, 1,2,3,3,3-pentafluoropropene, chlorotrifluoroethylene (hereinafter referred to as “CTFE”), vinyl fluoride. (Hereinafter referred to as “VF”). Moreover, as a fluorine-containing vinyl ether, perfluoro (vinyl ether) is mentioned, for example. Moreover, as perfluoro (vinyl ether), PAVE etc. are mentioned, for example.

As PAVE, for example,
Formula _{(1): CF 2 = CFO} (Rf a O) n (Rf b O) m Rf c ( wherein, Rf ^a and Rf ^b is different, 2 to 6 carbon atoms is a linear or branched of a perfluoroalkylene group, m and n are independently integers from 0, Rf ^c is a perfluoroalkyl group having 1 to 6 carbon atoms.), the compound represented by
Formula _{(2): CF 2 = CFO} (CF 2 CFXO) r Rf d (X is -F or -CF _3, r is an integer from 0 to 5, Rf ^d is 1 to carbon atoms 6 is a perfluoroalkyl group).
Formula _{(3): CF 2 = CFO} [(CF 2) u CF 2 CFZO] v in Rf ^e (wherein, Rf ^e is a perfluoroalkyl group having 1 to 6 carbon atoms, u is an integer of 0 or 1 in it, v is an integer from 0 to 5, Z is -F or -CF _3.) the compound represented by,
Formula _{(4): CF 2 = CFO} [(CF 2 CF (CF 3) O) m (CF 2 CF 2 CF 2 O) n (CF 2) y] in C _z F _{2z + 1} (wherein, m and n is an integer of 0 to 10 independently, y is an integer of 0 to 3, and z is an integer of 1 to 5 carbon atoms).
Formula (5): CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₃ O) _w C _x F _{2x + 1} (wherein, w is an integer of 1 to 5, and x is an integer of 1 to 3) And the like.

  The compound represented by the general formula (2) includes perfluoro (methyl vinyl ether) (hereinafter referred to as “PMVE”), perfluoro (ethyl vinyl ether) (hereinafter referred to as “PEVE”), perfluoro (propyl vinyl ether) ( (Hereinafter referred to as “PPVE”).

In the general formula (3), it is preferred that the Rf ^e is -C ₃ F _7, the u is 0, it is preferable that the v is 1.

  In the general formula (4), m and n are preferably independently 0 or 1, and z is preferably 1.

  In the general formula (5), x is preferably 1.

  Moreover, when a fluorine-containing elastomer has a PAVE unit, it is preferable that the PAVE unit in a fluorine-containing elastomer is 20-70 mass%. Moreover, when a fluorine-containing elastomer has a PMVE unit, it is preferable that the PMVE unit in a fluorine-containing elastomer is 30-55 mass%.

  Moreover, although it does not specifically limit as a hydrocarbon olefin, For example, although ethylene, propene, etc. are mentioned, propene is preferable.

  When the fluorine-containing elastomer which concerns on this embodiment has a hydrocarbon olefin unit, it is preferable that the hydrocarbon olefin unit in a fluorine-containing elastomer is 4-20 mass% of all the copolymer units.

  Specific examples of the fluorine-containing elastomer include a TFE / perfluoro (vinyl ether) copolymer, a VdF / HFP copolymer, a VdF / CTFE copolymer, and a VdF / HFP / TFE copolymer. And fluorine-containing copolymers such as VdF / CTFE / TFE copolymers, TFE / propylene copolymers, TFE / propylene / VdF copolymers, ethylene / HFP copolymers, etc. However, a VdF copolymer in which the first monomer is VdF or a TFE copolymer in which the first monomer is TFE is preferable.

  Examples of the TFE copolymer include a TFE / propylene copolymer and a TFE / PAVE copolymer.

Examples of the VdF copolymer include VdF / HFP copolymer, VdF / HFP / TFE copolymer, general formula: ICH ₂ CF ₂ CF ₂ O [CF (CF ₃ ) CF ₂ O] _y CF And a VdF copolymer having an iodine compound represented by = CF ₃ (y = 0 to 3) as a copolymer unit.

  Fluorine-containing elastomers are vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / hexafluoropropylene / fluorinated vinyl ether copolymer, vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, vinylidene fluoride. Ride / hexafluoropropylene / tetrafluoroethylene / fluorinated vinyl ether copolymer, vinylidene fluoride / chlorotrifluoroethylene copolymer, vinylidene fluoride / chlorotrifluoroethylene / fluorinated vinyl ether copolymer, vinylidene fluoride / chloro Trifluoroethylene / tetrafluoroethylene copolymer or vinylidene fluoride / chlorotrifluoroethylene / tetrafluoroethylene And particularly preferably a fluorine-containing vinyl ether copolymer.

  The method for polymerizing the fluorine-containing elastomer is not particularly limited, and a conventionally known method can be used. Among them, emulsion polymerization is preferable. The type and concentration of the polymerization initiator used in the polymerization, the polymerization temperature, and the polymerization pressure are not particularly limited.

<Resin dispersion continuous coagulation device>
A resin dispersion continuous coagulation apparatus 1 according to an embodiment of the present invention is an apparatus for coagulating a fluorine-containing elastomer aqueous dispersion to produce coagulated granules having a size within a predetermined range, As shown in FIG. 1, it mainly includes a first pipeline mixer 1A and a second pipeline mixer 1B. In the present embodiment, the second pipeline mixer 1B is the same pipeline mixer as the first pipeline mixer. Hereinafter, the details of the configuration of the pipeline mixers 1A and 1B will be described.

<Configuration of pipeline mixer>
The pipeline mixers 1 </ b> A and 1 </ b> B include a casing 10, a stirring rod 30, a seal mechanism 50, and a drive mechanism 70. Details of these components will be described in detail below.

<Pipeline mixer components>
(1) Casing As shown in FIGS. 2 and 3, the casing 10 mainly includes a main body 11, a lid 12, a resin dispersion supply pipe 13, a coagulation liquid supply pipe 14, and a resin coagulation particle discharge. It consists of a tube 15. In the casing 10, the axes of the main body 11 and the coagulated particle discharge pipe 15 are parallel to the horizontal plane (that is, the axes of the main body 11 and the coagulated particle discharge pipe 15 are perpendicular to the vertical direction) and The coagulating liquid supply pipe 14 is installed so as to face upward.

  As shown in FIGS. 2 and 3, the main body 11 is a cylindrical member, and is configured by detachably connecting three cylindrical members 11 a, 11 b, and 11 c. Hereinafter, for convenience of explanation, the cylindrical member 11a to which the lid portion 12 is attached is referred to as a “first cylindrical member”, and the cylindrical member 11b located at the center is referred to as a “second cylindrical member”, and resin coagulated particles. The cylindrical member 11c to which the body discharge pipe 15 is attached is referred to as a “third cylindrical member”. And these cylindrical members 11a, 11b, and 11c are connected by the flange 113 (refer FIG. 4). Further, the connecting portions of the cylindrical members 11a, 11b, and 11c are sealed by a seal ring 112 as shown in FIG. In the main body 11, the position corresponding to the grinding auxiliary blade 33 (described later) and the local stirring blades 36 a, 36 b, 36 c (described later) and the backflow auxiliary blade 37 in a state where the stirring rod 30 is attached to the drive shaft 71. A fixed blade 111 is formed at a position corresponding to between a later-described flow generation blade 38 (described later). As shown in FIG. 2, five sets of fixed blades 111 are formed along the axial direction of the main body 11, and four blades are prepared for each set as shown in FIG. 3. And this fixed blade | wing 111 is a flat blade | wing, Comprising: As FIG. 4 shows, the 1st surface containing the axis | shaft of the main-body part 11 and the axis | shaft orthogonal to the 1st surface including the axis | shaft of the main-body part 11 are shown. It extends from the inner peripheral surface of the main body part 11 toward the axis of the main body part 11 along the two surfaces.

  As shown in FIGS. 2 and 3, the lid 12 is a disc body having an outer diameter substantially the same as the outer diameter of the main body 11, and covers the opening at the first end of the main body 11. The lid portion 12 is formed with an insertion hole for fitting the resin dispersion supply pipe 13 substantially at the center. Moreover, the connection part of this cover part 12 and the 1st cylindrical member 11a is sealed by the seal ring 112, as FIG. 1 shows.

  As shown in FIGS. 2 and 3, the resin dispersion supply pipe 13 is welded to the lid portion 12 while being fitted in an insertion hole formed at substantially the center of the lid portion 12. In the present embodiment, the resin dispersion supply pipe 13 of the first pipeline mixer 1A is connected to a fluorine-containing elastomer aqueous dispersion tank (not shown), and the resin dispersion of the second pipeline mixer 1B. The supply pipe 13 is connected to the resin coagulated particle discharge pipe 15 of the first pipeline mixer 1A.

  As shown in FIGS. 2 and 3, the coagulating liquid supply pipe 14 is provided so as to penetrate the side wall of the end portion on the first end side of the main body portion 11. The coagulating liquid supply pipe 14 is welded to the first cylindrical member 11 a of the main body 11. In the present embodiment, the coagulation liquid supply pipe 14 of the first pipeline mixer 1A is connected to a coagulation liquid tank (not shown), and the coagulation liquid supply pipe 14 of the second pipeline mixer 1B. Is sealed. In the present embodiment, the coagulant is not particularly limited as long as it is usually used. For example, sulfuric acid, hydrochloric acid, nitric acid, aluminum sulfate, aluminum chloride, magnesium chloride, sulfuric acid Examples thereof include magnesium, calcium chloride, ammonium chloride, sodium nitrate, potassium alum, and PAC (polyaluminum chloride). Of these, aluminum sulfate is preferred.

  The resin agglomerated particle discharge pipe 15 is for discharging the resin agglomerated particles generated in the internal space SP of the casing 10 to the outside of the system. As shown in FIGS. Is provided through the side wall at a position slightly before the second end opposite to the first end. The resin coagulated particle discharge pipe 15 is perpendicular to the axis of the coagulation liquid supply pipe 14 when viewed along the axis of the main body 11. The resin coagulated particle discharge pipe 15 is welded to the third cylindrical member 11 c of the main body 11. In the present embodiment, the resin coagulated particle discharge pipe 15 of the first pipeline mixer 1A is connected to the resin dispersion supply pipe 13 of the second pipeline mixer 1B, and the second pipeline mixer 1B The resin coagulated particle discharge pipe 15 is connected to the lower end of the vertical stirrer 100 as shown in FIG.

  Note that the vertical stirring device 100 includes a stirring bar having an axis parallel to the vertical direction. The stirring bar has at least one stirrer blade. Such a vertical stirring apparatus 100 is excellent in quantitative discharge of coagulated particles. In addition, as the vertical stirring apparatus 100, the thing as described in Unexamined-Japanese-Patent No. 2-239911 is mentioned. Further, the coagulated particles can be continuously taken out from the vertical stirring apparatus 100 by an appropriate discharging means. As the discharging means, for example, a quantitative scraping method by an overflow method, a scraper method or the like can be adopted, and the overflow method is particularly preferable. The coagulated particles discharged from the vertical stirrer 100 are separated from water by a mesh or the like and are subjected to drying. In addition, a water separation process and a drying process can also be performed continuously. For example, the overflowing coagulated particle-containing liquid may be supplied onto a belt conveyor made of wire mesh and continuously fed into a dryer while separating water.

(2) Stirring bar As shown in FIG. 5, the stirring bar 30 mainly includes a shaft 31, a crushing blade 32, a crushing auxiliary blade 33, three fluid conveying blades 34 a, 34 b, 34 c, a shear blade 35, It comprises local stirring blades 36a, 36b, 36c, a backflow auxiliary blade 37 and a backflow generating blade 38. Hereinafter, for convenience of explanation, the fluid conveyance blade 34a on the pulverization blade side is referred to as “first fluid conveyance blade”, the fluid conveyance blade 34b located in the center is referred to as “second fluid conveyance blade”, and the fluid on the backflow generation blade side is referred to. The conveying blade 34c is referred to as a “third fluid conveying blade”, the local stirring blade 36a on the pulverization blade side is referred to as a “first local stirring blade”, and the local stirring blade 36b located in the center is referred to as a “second local stirring blade”. The local stirring blade 36c on the backflow generating blade side is referred to as a “third local stirring blade”.

  As shown in FIG. 5, the shaft 31 is a cylindrical bar. The shaft 31 is formed with a pin receiving hole (not shown) for connecting to the drive shaft 71 of the drive mechanism 70 at the end on the first end side.

  As shown in FIG. 6, the pulverization blade 32 includes four blades 321. And these blade | wings 321 are flat blade | wings, and go to the 1st end from the outer periphery of the part of the 2nd end side opposite to the 1st end of the shaft 31 from the 2nd end of the shaft 31 as a base point. It extends toward the outer circumferential direction as it goes in the opposite direction. In addition, as shown in FIG. 6, these blades 321 are evenly arranged along the outer periphery of the shaft 31 when viewed along the axis of the shaft 31, and the 21st including the axis of the shaft 31. The surface and the axis of the shaft 31 are formed so as to be inclined by 90 ° with respect to the 22nd surface orthogonal to the 21st surface.

  As shown in FIG. 7, the auxiliary grinding blade 33 is composed of four blades 331. The blade 331 is a flat blade, and extends outward from the outer peripheral surface of the shaft 31 along a thirty-first surface including the axis of the shaft 31 and a thirty-second surface including the axis of the shaft 31 and orthogonal to the thirty-first surface. It extends. Further, the blade 331 is formed so as to protrude toward the first end side in the axial direction of the shaft 31. Further, the auxiliary grinding blade 33 is provided adjacent to the grinding blade 32 as shown in FIG.

  As shown in FIG. 5, the fluid conveying blades 34a, 34b, and 34c are arranged at equal intervals along the axial direction of the shaft 31 in the second end side region from the center of the shaft 31, and are shown in FIG. As shown in the figure, each of the blades 341 is composed of three blades 341. The blades 341 are flat blades that intersect at an angle of 45 ° with respect to the axis of the shaft 31 as shown in FIG. 5, and are evenly distributed along the outer periphery of the shaft 31 as shown in FIG. 8. Has been placed.

  As shown in FIG. 5, the shear blade 35 is positioned near the third local stirring blade 36 c between the third local stirring blade 36 c and the backflow auxiliary blade 37, and as shown in FIG. It is composed of a single blade 351. As shown in FIG. 9, the blade 351 is a flat blade, and includes a shaft 51 along a 51st surface including the axis of the shaft 31 and a 52nd surface including the axis of the shaft 31 and orthogonal to the 51st surface. It extends toward the outside from the outer peripheral surface.

  As shown in FIG. 5, the local agitating blades 36a, 36b, 36c are provided between the first fluid conveying blade 34a and the second fluid conveying blade 34b, and between the second fluid conveying blade 34b and the third fluid conveying blade 34c. And between the third fluid conveying blade 34c and the shear blade 35, each of which is composed of four blades 361 as shown in FIG. As shown in FIG. 10, the blade 361 faces outward from the outer peripheral surface of the shaft 31 along a 61st surface including the axis of the shaft 31 and a 62nd surface including the axis of the shaft 31 and orthogonal to the 61st surface. It extends. The blade 361 has a length shorter than that of the fluid conveying blades 34a, 34b, 34c. The 61st surface is a surface that matches the 51st surface, and the 62nd surface is a surface that matches the 52nd surface.

  As shown in FIG. 5, the backflow auxiliary blade 37 is located near the backflow generating blade 38 between the shear blade 35 and the backflow generating blade 38, and as shown in FIG. And a baffle plate 372. As shown in FIG. 11, the blade 371 is a flat blade, and the shaft 31 extends along a 71st surface including the axis of the shaft 31 and a 72nd surface including the axis of the shaft 31 and orthogonal to the 71st surface. It extends toward the outside from the outer peripheral surface. The 71st surface is a surface that matches the 51st surface, and the 72nd surface is a surface that matches the 52nd surface. As shown in FIG. 11, the baffle plate 372 is an annular plate and extends from the outer peripheral surface of the shaft 31 to the central portion of the blade 371. Further, as shown in FIG. 5, the baffle plate 372 is formed so as to intersect the central portion of the blade 371 when viewed along a direction orthogonal to the axis of the shaft 31.

  The reverse flow generating blade 38 is a blade that creates a fluid flow in a direction opposite to that of the fluid conveying blades 34a, 34b, and 34c, and is located at the end portion on the first end side of the shaft 31 as shown in FIG. . And this backflow generation | occurrence | production blade | wing 38 is comprised from the two blade | wing 381, as FIG.12 and FIG.13 shows. As shown in FIG. 13, the blade 381 is a blade that curves as it goes outward from the outer periphery of the shaft 31, and is formed so as to oppose the shaft 31.

  As shown in FIG. 2, the stirring rod 30 is accommodated in the casing 10 such that the axis of the shaft 31 coincides with the axis of the main body 11 of the casing 10, and Connected to the drive shaft 71. In the state where the stirring rod 30 is accommodated in the casing 10 as described above, the internal space SP in which the pulverization blade 32 is accommodated is referred to as a “pulverization space SPc”. The internal space SP in which the blade 35 and the local stirring blades 36a, 36b, and 36c are accommodated is referred to as “shear space SPs”, and the internal space SP between the shear blade 35 and the backflow auxiliary blade 37 is referred to as “discharge space SPe”. The internal space that houses the backflow auxiliary blade 37 and the backflow generation blade 38 is referred to as a “backflow space SPr”.

(3) Seal mechanism The seal mechanism 50 separates the internal space SP from the drive mechanism 70 so that the liquid flowing into the internal space SP of the casing 10 does not enter the drive mechanism 70 through the drive shaft 71. The seal mechanism 50 is provided with a coagulation liquid passage on the side of the drive shaft 71, and the coagulation liquid flowing in the coagulation liquid passage is sent to the discharge space SPe by the backflow generating blade 38.

(4) Drive mechanism The drive mechanism 70 is an electric motor and rotates the drive shaft 71.

<Manufacture of resin coagulated particles using a resin dispersion continuous coagulator>
(1) Coagulation conditions The pipeline mixers 1A and 1B are operated under conditions that allow the aqueous fluoroelastomer dispersion to be aggregated in the internal space SP. This condition is determined by the number of rotations of the drive motor. When the gap between the casing 10 and the stirring rod 30 is about 5 to 10 mm, the peripheral speed of the stirring rod 30 is 2 to 20 m / sec, preferably 3 A range of ˜15 m / sec is preferable from the viewpoint of providing a uniform high shear force. The polymer concentration in the pipeline mixers 1A and 1B is preferably adjusted to 3 to 20% by mass, preferably 4 to 15% by mass.

(2) Coagulation step First, the drive shaft 71 is rotated by the drive mechanism 70 of the first pipeline mixer 1A and the second pipeline mixer 1B, and the stirring rod 30 of the first pipeline mixer 1A and the second pipeline mixer 1B. Rotate each. At this time, the first pipeline mixer 1A rotates the drive shaft 71 at a relatively high speed, and the second pipeline mixer 1B rotates the drive shaft 71 at a higher speed. Then, the fluorine-containing elastomer aqueous dispersion (usually at a temperature of 5 to 70 ° C. and a polymer concentration of 5 to 20 mass%, preferably 6 to 6) at a predetermined flow rate in the resin dispersion supply pipe 13 of the first pipeline mixer 1A. Then, the resin dispersion liquid and the coagulation liquid flowing in by the pulverization blade 32 are stirred and mixed and simultaneously generated by the stirring and mixing of the resin dispersion liquid and the coagulation liquid in the pulverization space SPc. The coagulated material is pulverized by the pulverization blade 32. As a result, coagulated particles having a size within a predetermined range are continuously produced in the pulverization space SPc. The fluid flow generated by the fluid conveying blades 34a, 34b, and 34c (hereinafter referred to as “carrying direction flow”) is sent to the shearing space SPs, where the coagulated particles and the unaggregated matter are contained in the shearing space SPs. , Carrying While flowing in the directional flow to the discharge space SPe, a shearing force is applied by the fluid conveying blades 34a, 34b, 34c, the local stirring blades 36a, 36b, 36c, and the fixed blade 111. As a result, the unaggregated fraction is reduced. At the same time, the shape of the coagulated particles is adjusted, and the coagulated particles that have reached the discharge space SPe by riding on the flow in the conveying direction are generated in the counterflow space SPr by the flow in the conveying direction and the counterflow generating blades 38. The water containing the coagulated particles and the non-coagulated components is pushed through the resin dispersion supply pipe 13 of the second pipeline mixer 1B by the flow in the reverse conveyance direction. The water containing the coagulated particles and the non-coagulated components is guided to the internal space of the second pipeline mixer 1B, and flows from the crushing space SPc to the shearing space SPs along the flow in the conveying direction. Then, in the shear space SPs, the unaggregated component flows on the flow in the conveyance direction and flows into the discharge space SPe, while the fluid conveyance blades 34a, 34b, 34c, the local stirring blades 36a, 36b, 36c, and the fixed blade 111. As a result, the unaggregated content is further reduced, and the aggregated particles that have reached the discharge space SPe by riding in the transport direction flow are flown by the transport direction flow and the backflow generation blade 38. It is pushed out to the resin coagulated particle discharge pipe 15 by the flow in the reverse conveying direction generated in the reverse flow space SPr and delivered to the vertical stirring device 100.

<Features of continuous coagulation equipment for resin dispersion>
(1)
In the resin dispersion continuous coagulation apparatus 1 according to the embodiment of the present invention, the fluorine-containing elastomer aqueous dispersion is subjected to a shearing force in the shear space SPs in the first pipeline mixer 1A, and then the second pipeline mixer. A shearing force larger than the previous shearing force is applied in the shearing space SPs in 1B. For this reason, if this resin dispersion continuous coagulation apparatus 1 is employ | adopted, coagulation time can be shortened from the resin dispersion, and the removal rate of a non-coagulated part can be improved. Therefore, if this resin dispersion continuous coagulation device 1 is employed, uncoagulated components will not accumulate in the vertical stirring device 100. As a result, if this resin dispersion continuous coagulation apparatus 1 is employed, excellent productivity can be realized.

  In addition, if the resin dispersion continuous coagulation apparatus according to the present invention is used, coagulated particles having an average particle diameter of 2 to 15 mm and more precisely 4 to 7 mm can be obtained. Moreover, if the resin dispersion continuous coagulation apparatus according to the present invention is used, the amount of uncoagulated water in the discharged wastewater is 0 to 100 ppm with respect to the wastewater, and more precisely controlled to 0 to 30 ppm. Can do.

(2)
In the resin dispersion continuous coagulation apparatus 1 according to the embodiment of the present invention, the first pipeline mixer 1A and the second pipeline mixer 1B are the same pipeline mixer. For this reason, in this resin dispersion continuous coagulation apparatus 1, different shearing forces can be generated in the first pipeline mixer 1 </ b> A and the second pipeline mixer 1 </ b> B only by changing the rotational speed of the drive shaft 71.

<Modification>
(A)
In the previous embodiment, the coagulation target is a fluorine-containing elastomer aqueous dispersion, but a resin dispersion other than the fluorine-containing elastomer aqueous dispersion, such as rubber latex, may be coagulated.

(B)
In the resin dispersion continuous coagulation apparatus 1 according to the previous embodiment, the second pipeline mixer 1B is provided with the pulverization blade 32 and the pulverization auxiliary blade 33. However, the pulverization blade 32 and the pulverization auxiliary are provided from the second pipeline mixer 1B. The wing 33 may be removed.

(C)
Although not particularly mentioned in the previous embodiment, a plurality of pipeline mixers similar to the second pipeline mixer 1B may be connected in series after the second pipeline mixer 1B. In such a case, it is necessary to make the rotational speed of the stirring rod of the pipeline mixer higher than the rotational speed of the stirring rod 30 of the second pipeline mixer 1B. In this way, the removal rate of uncoagulated components can be further improved.

(D)
Although not particularly mentioned in the previous embodiment, a coagulation liquid tank may be connected to the coagulation liquid supply pipe 14 of the second pipeline mixer 1B.

(E)
In the pipeline mixers 1 </ b> A and 1 </ b> B according to the previous embodiment, the drive motor is employed as the drive mechanism 70 that rotationally drives the stirring rod 30, but an engine or the like may be employed as the drive mechanism 70.

(F)
Although not particularly mentioned in the previous embodiment, concentration adjusting water or the like may be appropriately added to the pipeline mixers 1A and 1B.

(G)
In the resin dispersion continuous coagulation apparatus 1 according to the previous embodiment, the first pipeline mixer 1A rotates the drive shaft 71 at a relatively high speed, and the second pipeline mixer 1B rotates the drive shaft 71 at a higher speed. Was rotated to shorten the coagulation time from the resin dispersion and to improve the removal rate of uncoagulated components. However, in the first pipeline mixer 1A, the drive shaft 71 is rotated at a relatively low speed, and in the second pipeline mixer 1B, the drive shaft 71 is rotated at a relatively high speed to control the particle diameter of the coagulated particles. However, the removal rate of uncoagulated components may be improved. Therefore, if the resin dispersion continuous coagulation apparatus 1 is set in this way, coagulated particles with stable quality can be continuously produced. In such a case, the coagulation efficiency in the first pipeline mixer 1A may be insufficient.

(H)
In the resin dispersion continuous coagulation apparatus 1 according to the previous embodiment, the pipeline mixers 1A and 1B are employed. However, a pipeline mill may be employed instead of the pipeline mixers 1A and 1B. The thing which can apply a uniform high shear force instantaneously may be employ | adopted.

(I)
In the pipeline mixers 1A and 1B according to the previous embodiment, the stirring rod 30 as shown in FIG. 5 is adopted, but instead of this, even if the stirring rod 30A as shown in FIG. 14 is adopted. Good. The stirring bar 30A is the same as the stirring bar 30 according to the previous embodiment except for the pulverizing blade 32A. Further, the pulverizing blade 32A according to this modification is the same as the pulverizing blade 32 according to the previous embodiment, except that the blade 321A has an L-shaped shape.

(J)
In the previous embodiment, the number of blades in the pulverization blade 32, the pulverization auxiliary blade 33, the fluid conveyance blades 34a, 34b, 34c, the shear blade 35, the local stirring blades 36a, 36b, 36c, the backflow auxiliary blade 37, and the backflow generation blade 38. However, in the present invention, the number of blades of these blades is not particularly limited, and may be appropriately changed according to conditions. For example, the number of blades 321 of the crushing blade 32 may be six, or the number of blades 341 of the fluid conveying blade 34 may be four.

<Example>
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

  In each example and comparative example, each value was measured by the following method.

(1) Measurement of the amount of unaggregated matter in the waste water As a method for measuring the amount of unaggregated matter, a sedimentation method was used.

  The coagulated particle-containing liquid flowing out from the vertical stirrer outlet is supplied onto a nylon mesh having an opening of 100 μm, and the coagulated particles in the coagulated particle-containing liquid are captured by the nylon mesh. The waste water was collected in a 2 L beaker (mass: W1) placed under a nylon mesh.

  Then, the total mass (hereinafter abbreviated as “W2”) of about 2 L of waste water and beaker was measured. Next, 100 g of an aqueous aluminum sulfate solution having a concentration of 27% was added to the waste water and stirred to disperse the aluminum sulfate as a whole, and then the waste water was allowed to stand for 12 hours or more.

  A membrane filter (mass: W3) (47 mm, hydrophilic PTFE) having an opening of 1 μm, which was previously dried at 150 ° C. for 12 hours, allowed to cool in a desiccator, and weighed, was set in a vacuum filtration device, and the drained water left still. The polymer precipitated at the bottom of the beaker was passed through a vacuum filtration device to collect the precipitated polymer. Next, the beaker was washed with 50 g of pure water and filtered in the same manner. Subsequently, washing of the beaker was further repeated 5 times to recover all the polymer in the beaker. Finally, the polymer collected on the membrane filter was washed with 200 g of pure water. Further, the membrane filter is collected together with the polymer from the vacuum filtration device, the membrane filter and the polymer are put in a petri dish to prevent external contamination, and the membrane filter and the polymer are dried for 8 hours using a hot air dryer at 150 ° C. It was. Then, after sufficiently cooling in a desiccator, the combined mass (W4) of the polymer and the membrane filter was measured.

  The following formula was used as a formula for calculating the amount of uncoagulated.

Uncoagulated amount (ppm) = (W4-W3) / (W2-W1) × 10 ⁶
(2) Measurement of average particle diameter In order to prevent adhesion of coagulated particles, the coagulated particles were sampled in a petri dish together with water. And the major axis and the minor axis of all the coagulated particles in the petri dish were measured using calipers, and the average particle size was calculated.

Resin dispersion continuous coagulation device 1 and vertical stirrer 100 (inner diameter 340 mm, high) composed of first pipeline mixer 1A (inner diameter 125 mm, length 650 mm) and second pipeline mixer 1B (inner diameter 125 mm, length 650 mm) In a coagulation particle processing apparatus (see FIG. 1) consisting of 700 mm), a fluorine-containing aqueous dispersion (temperature 40 ° C.) in which particles of a VdF / HFP copolymer having a polymer concentration of 25% by mass are dispersed is 900 liters per hour. Is supplied to the first pipeline mixer 1A through the resin dispersion supply pipe 13 of the first pipeline mixer 1A, and a 0.1% by mass aluminum sulfate (Al ₂ (SO ₄ ) ₃ ) aqueous solution (as a coagulant) The temperature is 40.degree. C. at a rate of 2700 liters per hour through the coagulation liquid supply pipe 14 of the first pipeline mixer 1A. The fluorine-containing aqueous dispersion consecutively coagulation coagulation 析粒 body was continuously prepared by supplying to the type line mixer 1A. At this time, the rotation speed of the drive motor of the first pipeline mixer 1A is set to 1800 rpm, the rotation speed of the drive motor of the second pipeline mixer 1B is set to 2000 rpm, and the drive mora of the vertical agitator 100 is set. The number of revolutions was set to 360 rpm. And the coagulated particle containing liquid discharged | emitted from the vertical stirring apparatus 100 was isolate | separated into coagulated particle | grains and waste_water | drain with the mesh made from resin of 100 micron opening, and each property was measured. The results are shown in Tables 1 and 2.

(Comparative Example 1)
The coagulated particles containing liquid discharged from the vertical stirrer in the same manner as in Example 1 except that the second pipeline mixer was not used was coagulated using a resin mesh having an opening of 100 microns. Separated into body and drainage, the properties of each were measured. The results are shown in Table 1.

(Comparative Example 2)
The coagulated particle-containing liquid discharged from the vertical stirring apparatus is opened in the same manner as in Example 1 except that the second pipeline mixer is not used and the residence time in the vertical stirring apparatus is 150 seconds. Using a 100-micron resin mesh, it was separated into coagulated particles and waste water, and the properties of each were measured. The results are shown in Table 2.

<Comparison of uncoagulated amount due to difference in the number of coagulators installed>
When the residence time in the vertical stirrer was fixed at 30 seconds, in Example 1, the amount of unaggregated water in the wastewater could be reduced to about 1/10 compared to Comparative Example 1. Since most of the granule production in Example 1 is performed in the internal space of the first pipeline mixer, the addition of the second pipeline mixer has little effect on the particle size.

また、竪型撹拌装置での滞留時間を固定しない場合、実施例２では、比較例２に比べ、竪型撹拌装置での滞留時間を１／５以下とすることができ、排水中の未凝析分も低減することができた。

In addition, in the case where the residence time in the vertical stirring apparatus is not fixed, in Example 2, the residence time in the vertical stirring apparatus can be reduced to 1/5 or less, compared with Comparative Example 2, and the unaggregation in the waste water is reduced. The amount of analysis could also be reduced.

  The resin dispersion continuous coagulation method according to the present invention is characterized in that the particle diameter of coagulated particles can be easily controlled and the amount of uncoagulated particles can be reduced, and a fluorine-containing elastomer aqueous dispersion It can utilize suitably, when manufacturing a coagulation granule from resin dispersion liquids, such as.

It is a schematic diagram which shows the apparatus structure of the coagulation particle processing apparatus which consists of a resin dispersion continuous coagulation apparatus and a vertical stirring apparatus which concern on one embodiment of this invention. It is a plane fragmentary sectional view of the pipeline mixer which concerns on one embodiment of this invention. It is a side view of the pipeline mixer which concerns on one embodiment of this invention. In the pipeline mixer which concerns on one embodiment of this invention, it is the figure which piled up the sectional view of the stirring rod, the sectional view of the main-body part of a casing, the front view of a flange, and the longitudinal cross-sectional view of a resin coagulation particle discharge pipe is there. It is a side view of the stirring rod of the pipeline mixer which concerns on one embodiment of this invention. It is a rear view of the crushing wing | blade of the pipeline mixer which concerns on one embodiment of this invention. It is AA sectional drawing of the grinding auxiliary blade of the pipeline mixer which concerns on one embodiment of this invention. It is a front view of the fluid conveyance wing | blade of the pipeline mixer which concerns on one embodiment of this invention. It is BB sectional drawing of the shearing blade of the pipeline mixer which concerns on one embodiment of this invention. It is CC sectional drawing of the local stirring blade of the pipeline mixer which concerns on one embodiment of this invention. It is DD sectional drawing of the backflow auxiliary blade of the pipeline mixer which concerns on one embodiment of this invention. It is a front view of the backflow generation | occurrence | production blade of the pipeline mixer which concerns on one embodiment of this invention. It is EE sectional drawing of the backflow generation | occurrence | production blade of the pipeline mixer which concerns on one embodiment of this invention. It is a side view of the stirring rod which concerns on modification (I).

1A 1st pipeline mixer (1st coagulation device)
1B Second pipeline mixer (second coagulation device)

Claims (4)

A first shearing step of applying a first shearing force to the resin dispersion or the coagulated resin dispersion;
A second shearing step of applying a shearing force different from the first shearing force to the coagulated resin dispersion generated from the resin dispersion in the first shearing step or the coagulated resin dispersion subjected to the first shearing step. A resin dispersion continuous coagulation method comprising :
The resin dispersion is a fluorine-containing elastomer aqueous dispersion,
The first shearing step is performed by a pipeline mixer (1A) driven by a first driving source, and the second shearing step is driven by a second driving source provided independently of the first driving source. Pipeline mixer (1B)
The resin dispersion continuous coagulation method , wherein the rotational speed of the drive shaft of the pipeline mixer (1B) is higher than the rotational speed of the drive shaft of the pipeline mixer (1A) . The resin dispersion continuous coagulation method according to claim 1 , wherein the second coagulation device is the same pipeline mixer as the first coagulation device. A resin dispersion continuous coagulation method in which different shearing forces are applied stepwise to the resin dispersion ,
The resin dispersion is a fluorine-containing elastomer aqueous dispersion,
The first shearing step is performed by a pipeline mixer (1A) driven by a first driving source, and the second shearing step is driven by a second driving source provided independently of the first driving source. Pipeline mixer (1B)
The resin dispersion continuous coagulation method , wherein the rotational speed of the drive shaft of the pipeline mixer (1B) is higher than the rotational speed of the drive shaft of the pipeline mixer (1A) .   The pipeline mixers (1A) and (1B) have a casing and a stirring rod, the gap between the casing and the stirring rod is about 5 to 10 mm, and the peripheral speed of the stirring rod is 2 to 20 m / sec. The polymer dispersion continuous coagulation method according to any one of claims 1 to 3, wherein the polymer concentration in the pipeline mixers (1A) and (1B) is 3 to 20% by mass. .

Images