KR101711243B1 - Method and apparatus for preparing resin powders - Google Patents

Abstract

The present invention relates to a process for producing a polymer resin powder and an apparatus for producing the polymer resin powder. According to the present invention, the surface of fine particles is treated with a nonionic emulsifier during the production of a resin powder containing fine particles by an aggregation process of polymer latex It is advantageous to improve the productivity by not only reducing the content of fine particles contained in the fine particles but also improving the powder characteristics by injecting the fine particles into a flocculation apparatus which simultaneously mixes and ages the mixture with fresh latex .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer resin powder,

The present invention relates to a method and an apparatus for producing a polymer resin powder, and more particularly, to a method and apparatus for producing a polymer resin powder which suppresses generation of fine particles and maximizes production efficiency in the production of powder of polymer latex. .

The polymer material formed by the emulsion polymerization is preferably processed into a powder to reduce the volume, various usability, and ease of handling. In order to obtain a polymer substance formed by emulsion polymerization as a powder, it is required to coagulate, aged, dehydrate and dry the latex formed by emulsion polymerization.

Flocculation of Emulsion Polymeric Polymer Latexes can be accomplished by chemical methods using various flocculants or by breaking the stability of the latex particles stabilized by the emulsifier applied during emulsion polymerization by a mechanical method using a mechanical force with a strong shearing force . In order to ensure the stability of the latex, the chemical method breaks the stability by using other coagulant depending on the type of the emulsifier used. When the stability is broken by the mechanical method, a strong shear force is applied to the latex to increase the repulsive force between the emulsifier Overcome and clump the latex particles and particles.

Rapid coagulation has been proposed as a method for preparing a polymer latex as a powder. This method rapidly injects an aqueous solution of coagulant such as inorganic salt and acid to break the stability of the emulsifier, thereby rapidly aggregating the polymer in the latex. The coalescence of the polymer particles of the latex is referred to as coagulation and the aggregation of the polymer particles is referred to as slurry. Since they are physically weakly bonded, they are easily broken by external shear force by a stirrer or the like (break-up). Thus, the agglomerated slurry is subjected to an aging process, which is a process of heating the slurry to strengthen the binding force by interpenetrating the chains. The slurry thus obtained is subjected to dehydration and drying to finally obtain a powdery phase.

Rapid agglomeration using agglomerates with excessive amounts of the agglomerates breaks the stability of the latex very quickly, so that the process of entangling the polymer latex particles occurs very quickly and disorderly. This disordered aggregation causes a problem that the apparent specific gravity is lowered and the particle size distribution of the final particles becomes very wide.

1 is a schematic flow chart of an apparatus for producing a polymer latex resin powder according to the prior art. The apparatus largely comprises a latex storage tank 1, a flocculation tank 2, an aging tank 6, a dehydrator 8 and a fluidized bed dryer 10.

Specifically, the flocculant solution (4) is put into the flocculation tank (2) and filled up to the top of the tank. Then, the steam 3 is introduced to raise the internal temperature to the coagulation temperature. After the temperature of the flocculation tank rises to the flocculation temperature, the latex is transferred from the latex storage tank 1 to the flocculation tank 2. The resulting slurry is transferred to the slurry storage tank 7 via the aging tank 6.

Then, the dehydration is continuously performed while supplying the slurry to the centrifugal dehydrator 8 by using a pump. At this time, the waste water 9 produced by the dehydration is discarded. Then, the dehydrated slurry is supplied to the fluidized bed dryer 10 together with the air. The supplied air is dried in a drier while moving the slurry up and down. When the dried particles are supplied to the cyclone 1 (11) by air, the large-sized regular particles (12) fall down and become light and small, The particles are transferred to cyclone 2 (13) and recovered (14) and air is discharged through line (15). However, the apparatus is not only difficult to agitate the slurry having a high viscosity, but also can not smoothly transfer the slurry, resulting in a reduction in the processing efficiency of the powder. Therefore, there is a limitation that it is difficult to use a slurry having a high solid content in order to increase the dewatering and drying efficiency, and there is a problem that much time, effort and energy are consumed in the subsequent dewatering and drying.

In order to improve these, multistage continuous aggregation and aging processes have been proposed. This process has the advantage of effectively aging a polymer slurry having a low solids content. However, it can not be applied to a slurry having a high solid content, and there is a problem in that it is somewhat inferior in terms of process efficiency because it must go through several steps.

Also, a slow coagulation process has been proposed which improves the powder properties of the final particles formed by controlling the coagulation rate through the partial introduction of the coagulant. This is because the coagulation takes place in the second well region where the energy barrier exists, so that the coagulation speed is slow and the particles can be rearranged, so that spherical particles can be produced by regular filling. However, the total amount of coagulant used is similar to that of the rapid aggregation, and it is merely a method of coagulation by performing a batch addition. Therefore, it is impossible to prevent the generation of waste water by the excessive flocculant. In the case of the first flocculation tank, since a small amount of flocculant is added compared to the flocculation flocculation, the viscosity of the slurry is increased, And has a high water content as compared with the rapid aggregation.

In both of the above methods, the flowability of the polymer latex slurry after agglomeration is influenced by the solid content, the particle size distribution of the slurry, and the inclusion water content of the slurry, which are most influenced by the solid content. If the solid content of the slurry is above a certain level (usually 27% or more), the flowability of the slurry rapidly deteriorates and becomes a lump, making it impossible to operate. Therefore, in order to smooth the flow of the slurry, an excess amount of water must be added to the aggregate. The excessive addition of water raises the energy cost of raising the temperature of the slurry to the agglomeration temperature and the aging temperature, and excess waste water is generated in the dehydration process to increase the post treatment cost. In addition, steam can not be used directly, but it is condensed into water, which is a medium, to transfer energy to the slurry. That is, when the agglomeration and aging are separated, a lot of energy costs and time are consumed.

Korean Unexamined Patent Publication No. 2000-0055793 discloses a technique for adjusting the interfacial tension and adjusting the pine content by adding an emulsifier to the aged slurry itself after agglomeration. However, since a large amount of an emulsifier which affects the color of the resin after the extrusion processing is used, discoloration of the resin is caused. Further, after the agglomeration and aging, a lot of bubbles are generated in the dehydration process by injecting the emulsifier, which makes it difficult to operate the continuous process.

Korean Patent Laid-Open Publication No. 2007-0035778 discloses a technique of recovering fine particles after dehydration and drying after multistage agglomeration and aging, treating them with an anionic emulsifier. However, several reactors are required for multi-stage agglomeration and aging, and a large amount of water must be added for stable operation of the process. In addition, additional water must be added to the surface of the fine particles to increase the energy cost and increase the amount of wastewater generated. In particular, the use of the anionic emulsifier necessitates the addition of the coagulant, which requires excessive energy cost.

Therefore, there is still a need to develop a technique for efficiently producing fine particles and recovering and recovering powder of polymer latex economically.

In order to solve the problems of the prior art described above, the inventors of the present invention have found that when a coagulation apparatus that simultaneously performs coagulation and aging is used, fine particles in the apparatus are agglomerated by high viscosity and mechanical force, By acting as a seed, the formation of fine particles is inhibited and surface treatment with a nonionic emulsifier induces a state in which the repulsive force due to anionic emulsifier is excluded, so that the stability of the latex is broken by the coagulant and easily participates in flocculation. As a result, The ratio can be reduced and the powder characteristics can be improved at an economical energy cost, and the present invention has been accomplished.

That is, an object of the present invention is to provide a method and an apparatus for producing a polymeric resin powder, which can efficiently produce fine particles and recover the polymeric particles and recover the polymeric latex powder economically.

According to the present invention, in the production of a resin powder containing fine particles by an aggregation process of a fresh polymer latex, fine particles among the fine particles are put into a device for both agglomeration and aging, and circulated to the above- Is subjected to classification and surface treatment, and then introduced into the above-mentioned process in the form of a mixed phase with a fresh polymer latex.

Further, according to the present invention, it is possible to provide a method for producing a fine polymer latex, which comprises a means for aggregating and aging the fresh polymer latex, a dehydrating means, a drying means, a means for recovering the polymer resin powder, a means for separating residual fine particles, And means for mixing the particle solution with the fresh polymer latex. The present invention also provides an apparatus for producing a polymer resin powder.

According to the present invention, a resin powder containing fine particles is prepared by means of coagulation and aging, and the fine particles are treated separately with a nonionic emulsifier to reduce the efficiency of the dewatering process when mixed with fresh latex, It is possible to reduce the content of fine particles as well as the content of fine particles which cause a risk of fire due to the use of the fine particles, thereby providing a resin powder having uniform powder characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart for manufacturing powder comprising a multi-stage agglomeration and aging process of a polymer latex according to the prior art.
Fig. 2 is a flow chart for preparing powder of polymer latex by surface treatment of fine particles according to the present invention, and agglomeration and aging means.
Fig. 3 is a schematic cross-sectional view of the agglomerating and aging means in Fig. 2;
Fig. 4 is a schematic cross-sectional view of a screw used in the coagulation and aging means of Fig. 2;

Hereinafter, the present invention will be described in detail with reference to the drawings.

The term "fine particles" used in the present invention refers to particles having a weight-average particle diameter of not more than 75 탆 measured by a particle size analyzer (HAVER EML 200 digital plus-test sieve shaker or the like) "Course particle " refers to a particle having a weight-average particle diameter of 1400 탆 or more unless otherwise specified.

The term "fresh polymer latex" refers to a polymer latex newly introduced into the coagulation process for coagulation, and the term "powder characteristics" refers to the content ratio of the course particles to the fine particles, and the term "fine polymer latex" When the content of the particles is all reduced, the powder properties can be improved.

Furthermore, the "agglomerating and aging unit" is an apparatus capable of simultaneously carrying out the agglomeration process and the aging process, and refers to the apparatus shown in Fig. 3 unless otherwise specified.

The method for producing the polymer resin powder of the present invention is a method for improving the powder characteristics by reducing the content of fine particles contained in the final dried particles when the resin powder containing fine particles is produced by the coagulation process of the polymer latex As a technical feature.

Specifically, the present invention relates to a process for producing a resin powder containing fine particles by an aggregation process of a polymer latex, wherein fine particles of the fine particles are put into a device for both agglomeration and aging to circulate the process, Characterized in that the particles are subjected to classification and surface treatment and then introduced into the above-mentioned process as a mixed phase with the fresh polymer latex.

As another example, the present invention relates to a process for producing a polymer latex, which comprises mixing a fresh polymer latex with a polymer latex of a fine particle surface-treated, Mixing process, and a mixing process.

2 shows an apparatus for producing a polymer latex resin powder according to an embodiment of the present invention. Referring to FIG. 2, the apparatus for producing an agglomerated and agitated slurry in an anionic emulsion polymerization latex according to the present invention comprises a hollow reaction tube, and at least an inner side wall extending from the inner wall of the reaction tube At least one stirrer protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, wherein the at least one stirrer includes a plurality of stirrers, An agitating and agitating device in which a continuous screw is provided at the lower part of the apparatus with a supply pipe of a flocculating agent and steam; A centrifugal dehydrator for dehydrating the coagulated agglomerated slurry and separating the dehydrated slurry; A first cyclone and a second cyclone sequentially connected to air dry the dehydrated slurry to separate fine particles having a weight average particle diameter of 75 탆 or less; And an inline mixer for surface-treating the water dispersion of the fine particles separated from the second cyclone with a nonionic emulsifier to provide a surface-treated fine particle-containing solution; A stoichiometric mixer for further adsorbing a non-bonding nonionic emulsifier to the surface-treated fine particle-containing solution and discharging the obtained surface-treated fine particle-containing solution to the mixture with the anionic emulsion polymerization fresh latex; And the mixture discharged from the static mixer is introduced into the agglomerating and aging device.
A connection pipe is formed at one end and the other end of the agglomerating and aging device (2). At one end 20, a latex mixed with fresh latex, fresh latex and surface treated fine particle solution is supplied at the start of the reaction, and the agglomerated slurry is discharged at the other end. The fresh latex is supplied from the storage tank 1 of the fresh latex by a required amount through a pump or a valve (not shown). The above-mentioned fresh latex refers to a polymer latex in which an anionic emulsifier component remains, as described above.
The agglomerating and aging device 2 is provided with a coagulant inlet pipe 4 for supplying an aqueous solution of the flocculant and a steam inlet pipe 3 for introducing steam so that flocculation and aging can be smoothly performed. For example, the flocculant solution (4) is filled up to the top of the agglomerating and aging means in the agglomeration aging device (2). Steam 3 is supplied to raise the internal temperature of the coagulation aging device 2 to the coagulation temperature. When the temperature in the agglomerating device 2 is raised to the coagulation temperature, the fresh latex 19 is introduced into the agglomerating device 2 from the latex storage tank 1 by using a pump and the manufacturing process can be started have.
The coagulated slurry discharged to the other end of the coagulation aging device 2 is stored in a slurry storage tank 5 and is supplied to a dehydrator 6 for dehydrating through a pump (not shown). The dehydrator 6 may be, for example, a centrifugal dehydrator generally used. The wastewater discharged from the dehydration is discharged to the lower portion of the dehydrator 6. [
The dehydrated slurry is conveyed to the fluidized bed dryer (8). The fluidized bed dryer 8 can be dried while moving the slurry up and down by injecting air, thereby improving the drying efficiency while maintaining the physical properties of the latex.
The dry particles discharged from the fluidized bed dryer (8) are supplied to the cyclone 1 (9) for separating genuine particles having large particles together with air. The fine particles discharged to the upper portion of the cyclone 1 9 are supplied to the cyclone 2 12 for recovery and discharged through the lower portion of the cyclone 2 12.
The obtained fine particles are transferred to the fine particle mixed solution tank 14 so as to be charged with water and to be stored as a fine particle mixed solution. The fine particle mixed solution in the fine particle mixed solution tank 14 is supplied to the inline mixer 16 through a pump and a nonionic emulsifier is used in the inline mixer 16 so that an anionic emulsifier remains in the latex Lt; / RTI > Particularly, since the nonionic ionic emulsifier is continuously supplied through the nonionic emulsifier input part 17 provided in the inline mixer 16, the polymer latex powder can be continuously produced in the apparatus for producing a polymer latex powder of the present invention, Do.

The surface-treated fine particle solution discharged from the inline mixer 16 further adsorbs unbound residual nonionic emulsifier, and the obtained surface-treated fine particle-containing solution is discharged into the anion emulsion from the latex storage tank 1 And then supplied to the static mixer 18 for mixing with the polymerized fresh latex and supplied continuously to the aforementioned agglomerating and aging device 2.

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Specifically, the surface treatment of the residual fine particles includes, for example, 0.2 to 0.5 parts by weight of a nonionic surfactant based on 100 parts by weight of the solid content in the latex, 4 parts by weight or less of the fine particles, or 0.1 to 3 parts by weight, Or 0.25 to 0.5 part by weight of the surface treatment solution. The surface treatment solution may be added to the surface treatment solution in a concentration of 1 to 10 v / v%, 2.5 to 10 v / v%, or 2 to 5 v / v% Water can be supplied.

The nonionic surfactant may be, for example, a water-soluble nonionic surfactant such as a sorbitan fatty acid ester or a propylene glycol fatty acid ester, or a nonionic surfactant such as a water-insoluble ethoxylated liner alcohols, Ethoxylated alkyl phenols, fatty acid ester-based (other than water-soluble), amine or amine derivatives, alkyl polyglucosides, ethylene oxide / propylene oxide copolymers, poly Alcohol and polyalcohols and ethoxylated polyalcohols may be mixed with the water-soluble surfactant.

For reference, the nonionic surfactant is mostly adsorbed on the surface of the fine particles through the surface treatment process, and some residual surfactant remains in the unbound state in the water. When the obtained surface treated fine particle sol is continuously and uniformly mixed with the fresh polymer latex through the static mixer 22, the residual nonionic surfactant in the unbonded state is adsorbed on the latex surface again.

These adsorbed latexes meet with the coagulant in the agglomerate aging device and break their stability. At this time, the number of the fine particle sol surrounded by the nonionic emulsifier is smaller than that of the fresh latex particles, so that the fine particles are easily surrounded by the latex particles, The fine particles become seeds and become aggregated rapidly.

This principle can be used to treat fine particles with a non-ionic emulsifier and then coagulate after mixing with fresh latex to effectively remove fine particles.

The agglomerate aging means 16 is also provided with an additional amount of 50 to 70% of water added to adjust the total solid content (TSC) in the conventional flocculation tank 2 (the solid content of the slurry is 30 wt% or (When the slurry solids content is 44wt%), or when the slurry is solidified (35wt%) or when the slurry solid content is 44wt%, the effect is much larger because the latex state has high solids content (TSC standard 30wt% or more).

Because of this high solids content, the coagulation will increase the viscosity of the coagulated particles. Under such a high viscosity, the movement of the fine particles will become smaller, allowing them to coalesce with the relatively small latex particles in the vicinity.

Also, the surface-treated fine particle-containing solution to be added to the agglomeration aging step may be, for example, 3 parts by weight or 0.5 to 3 parts by weight based on 100 parts by weight of the solid content in the fresh polymer latex.

The agglomeration and agglomeration process may be carried out at a temperature of 60 to 98 ° C, or 60 to 80 ° C, for 30 seconds to 10 minutes, or 1.5 minutes to 5 minutes, with steam input.

The agglomerating and aging step is carried out by using at least one coagulant selected from hydrochloric acid, sulfuric acid, phosphoric acid, sulfate and calcium salt using 0.5 to 1.5 parts by weight, or 0.5 to 1.0 part by weight, based on 100 parts by weight of fresh polymer latex.

The water may be mixed with the coagulant in accordance with the solid content of the slurry, for example, the solid content of 30 wt%.

As a specific example, the solid content of the slurry may be 10 to 90 wt%, or 10 to 50 wt%, and the solid content of the fresh polymer latex may be 30 to 60 wt%, or 30 to 50 wt%.

Examples of the fresh polymer latex include a styrene polymer latex, a butadiene polymer latex, a styrene-butadiene copolymer latex, an alkyl acrylate polymer latex, an alkyl methacrylate polymer latex, an alkyl acrylate-acrylonitrile copolymer latex, Butadiene-styrene copolymer latex, an acrylonitrile-butadiene-styrene copolymer latex, an acrylonitrile-alkyl acrylate-styrene copolymer latex, an alkyl methacrylate-butadiene-styrene copolymer latex, and an alkyl acrylate-alkyl methacrylate Latex copolymer latex.

As a specific example, the fresh polymer latex includes a graft copolymer including a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound. The graft copolymer is prepared by polymerizing a monomer mixture of an aromatic vinyl compound and a vinyl cyan compound with a conjugated diene compound.

The conjugated diene compound may be selected from the group consisting of a butadiene rubber (BR), an ethylene-propylene-diene monomer rubber (EPDM), an ethylene-propylene rubber (EPR), a halobutyl rubber, a butyl rubber, a styrene- Butadiene rubber (SBR).

In addition, the vinyl cyan compound is selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof.

The aromatic vinyl compound is selected from the group consisting of styrene, alphamethylstyrene, alphaethylstyrene, para-methylstyrene, vinyltoluene, and derivatives thereof.

As another example, the graft copolymer may include 40 to 70 wt% of butadiene, 5 to 20 wt% of acrylonitrile, 10 to 40 wt% of styrene, and a solid content of 30 to 60 wt%.

The polymeric resin powder can be provided by the powder production method of the present invention, wherein the powder has 5 to 7 wt% of course particles and 0 to 1 wt% of fine particles, Can be excellent.

As described above, the apparatus for producing a polymer resin powder of the present invention is characterized in that it comprises means for aggregation and aging of fresh polymer latex, means for dehydrating, drying means, means for recovering polymer resin powder, means for separating residual fine particles, A surface treatment means, and a means for mixing the surface treated fine particle solution with the fresh polymer latex.

Fig. 3 specifically shows the configuration of the agglomerating and aging device 2. Referring to FIG. 3, the coagulation aging device 2 (denoted by reference numeral 100 in FIG. 3) includes a hollow reaction tube 160 through which the latex is passed, and a reaction tube 160 extending from the inner wall of the reaction tube 160 At least one stirrer 150 protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, and at least one stirrer 150 protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, Wherein at least one of the at least one stirrer 150 is a non-continuous screw 210 and the latex mixed with the fresh latex discharged from the static mixer 18 and the surface-treated fine particle solution is agglomerated and aged Is supplied to the device (2).
As shown in FIG. 3, the coagulation and aging means includes a hollow reaction tube 160 through which the latex passes, at least one reaction tube 160 extending from the inner wall of the reaction tube 160 toward the inside of the reaction tube 160 At least one stirrer protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, wherein the at least one stirrer is discontinuous And a reactor 100 (corresponding to reference numeral 2 in FIG. 2) which is a type of screw 210.

That is, at least one of the plurality of stirrers 150 is replaced with the non-continuous screw 210 to induce the turbulent flow of the latex, thereby increasing the mixing efficiency of the latex and the flocculant, reducing the water content of the slurry, The present invention is characterized in that the color of the polymer resin powder obtained by reducing the amount of the coagulant required for the coagulation process is improved and the quality improvement effect is provided . The cross section of the reaction tube 160 may be any polygonal or circular, and preferably circular.

The reactor 100 includes a hollow reaction tube 160 through which the latex passes and at least one reaction tube 160 protruding from the inner wall of the reaction tube 160 toward the inside of the reaction tube 160, A plurality of barrel pins 140 projecting from the outer surface of the rotating shaft 170 toward the inner wall of the reaction tube 160, a rotating shaft 170 extending along the longitudinal center axis of the reaction tube 160, And the reaction tube 160 is connected to the latex injection line 110 and the coagulant injection line 120 and the steam injection line 130 so as to be introduced into the reaction tube 160 To supply the latex, flocculant and steam.

In one embodiment of the present invention, the non-continuous screw 210 may be provided in the reactor 100 in the range of 1 to 20, 4 to 16, or 8 to 12, (Non-condensing steam and latex) and induces turbulent flow of the latex to increase the mixing efficiency of steam, latex and flocculant. However, the present invention is not limited to this, and the non-continuous screw 210 ) Can be arranged in an appropriate number according to the length (L) of the reactor 100, as will be understood by those skilled in the art. Also, the non-continuous screw 210 may be a biaxial screw, and the non-continuous screw 210 used in the present invention is shown in more detail in FIG.

4, the discontinuous screw 210 used in the present invention includes a rotary blade 212 extending radially from the outer surface of the screw shaft 211 around a central screw shaft 211 And at least one opening (214) formed by at least a part of the opening (214) being discontinuous. The opening 214 is formed in a direction in which the latex is conveyed by the rotation of the non-continuous screw 210 in the rotation direction (counterclockwise about the screw shaft 211 in the rotation direction in FIG. 2) (The conveying direction in FIG. 2), that is, a direction extending along an axis in the longitudinal direction of the screw shaft 211 is not formed. 5A), three (FIG. 5B), or four (FIG. 5C) openings 214 and may be two as shown in FIG. 4, The present invention is not limited thereto, and a larger number of openings 214 may be formed.

A barrel pin 140 extending from the outside to the inside of the reaction tube 160 is fixed to the reactor 100 according to the present invention and the stirrer 150 and / The diaphragm screw 210 is rotatably fixed. More specifically, the reaction tube 160 of the reactor 100 includes at least one barrel fin 140 extending from the outside of the reaction tube 160 into the reaction tube 160. The stirrer 150 and / or the discontinuous screws 210 rotate between the barrel pins 140 fixed to the reaction tube 160, so that the reaction tube 160 The latex is brought into contact with the rotating blades of the stirrer 150 and / or the discontinuous screw 210 to receive a mechanical force therefrom, The latex stabilized by the emulsifier added at the time of emulsion polymerization is broken by the mechanical method and is thereby agglomerated, And is aged in the latter half of the reaction tube 160.

The shape of the barrel fin 140 may be any of circular, triangular, oblique, elliptical, rhombic, rectangular, etc., and is not particularly limited. In the case of the stirrer 150, any of paddles, screws, biaxial screws, Available.

The reactor 100 including the discontinuous screw 210 is connected to the latex obtained by the emulsion polymerization by the action of the barrel pin 140 and the internal stirrer 150 and / It is possible to control the water content by using the mechanical force by making a force.

The reactor 100 includes a polymer latex injection line 110, a coagulant injection line 120 and a steam injection line 130. An aggregation reaction takes place at a portion close to the location where the polymer latex, coagulant and steam are introduced, Aging reaction occurs in the latter half of the reactor, so that agglomeration and aging can be performed simultaneously in substantially the same reactor.

In the present invention, the surface treatment means may be a mixer type which induces mixing with a fluid through a strong shearing force such as an inline mixer, and the mixing means may be a simple mixer by changing a fluid flow line on a piping such as a static mixer, Can be used.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  One

This example corresponds to an experimental example for showing the circulation and aggregation of fine particles in the polymer resin powder according to FIG.

≪ Polymeric resin Powdery  Manufacturing>

(AN) -butadiene (BD) -styrene (SM) copolymer (AN / BD / SM) as a graft copolymer containing a vinyl cyan compound-conjugated diene compound-aromatic vinyl compound as a fresh polymer latex, 13/60/27, solid content 44 wt%) was used.

Specifically, the latex is placed in a reactor (100 - Fig. 2 (b)) comprising a total of eight noncontinuous screws (210) in a coagulation and aging unit (2) ) At a flow rate of 12 kg / hr, and 1.0 part by weight of diluted sulfuric acid (H2SO4) was used as a coagulant with respect to 100 parts by weight of the solid content in the fresh polymer latex.

Water was added to the reactor 100 so that the solid content of the slurry became 30 wt% while steam was directly fed into the reactor 100, and sulfuric acid was added to the water to be added.

The residence time of the reactor 100 was 1.5 pct on average and the agglomeration and aging temperature was 75 캜. The agglomerated slurry exits through the agitator and is transferred to the slurry storage tank 5. Thereafter, dehydration was continuously performed while supplying the slurry to the centrifugal dehydrator (6) using a pump, and the generated dehydrated wastewater (7) was discharged.

Then, the dehydrated slurry and air are supplied into the fluidized bed dryer (8). The air supplied was dried by moving the slurry up and down, and the finally dried particles were supplied to the cyclone 1 (9) by air.

In the cyclone 1 (9), the large-particle particles 10 fall down and light and small fine particles are transferred to the cyclone 2 (12) to be recovered (13) and air is discharged.

<Circulation and aggregation of fine particles in polymer resin powder>

Then, the fine particles recovered (13) were transferred to a fine particle mixed solution tank (14) and charged with water (15) to obtain a fine particle mixed solution. 3 parts by weight (based on 100 parts by weight in total of the polymer latex) was transferred to the inline mixer 16 using a pump and 0.5 part by weight of a 1 wt% sorbitan fatty acid ester as a nonionic emulsifier 17 was added to the inline mixer 16 Based on 100 parts by weight of the solid content in the latex of the polymer) is continuously introduced and the water is not added, whereby the emulsifier is adsorbed on the surface by the shear force of the mixer, there was.

The obtained surface treated fine particle sol was supplied to the static mixer 18 between the latex storage tank 1 and the agglomerating agitator 2 (reactor 100 in FIG. 3) through a circulation line.

At this time, the latex 20 in which the fresh latex and the surface treated fine particle solution were mixed was prepared by continuously feeding the fresh polymer latex 19 from the latex storage tank 1, and the above-described processes were repeatedly performed.

The recovered resin powders were measured for particle size through a vibration process using a mesh (7 kinds) (HAVER EML 200 digital plus-test sieve shaker), the content of coarse particles having a weight average particle diameter of 1400 μm or more Was 5.1 wt%, and the content of fine particles having a weight average particle diameter of 75 탆 or less was 0.5 wt%. Bulk density can also be calculated by measuring the weight of a cup with a volume of 100 cc by dropping the powder at a constant speed from a storage space capable of continuously feeding powder at a height of 15 cm into a 1 cm diameter groove. The calculation method was calculated by dividing the measured weight by the total volume 100, and the bulk density value thus measured was 0.34 g / cc.

Example  2 to 7

In the same manner as in Example 1 except that the solid content of the polymer latex slurry in Example 1, the nonionic emulsifier content, the fine particle sol concentration, the fine particle content and the like were changed to the values shown in the following Table 1 And the polymeric resin powder was prepared. The bulk density, the content of coarse particles and the fine particles were measured in the same manner, and the results are summarized in Table 1 below.

Comparative Example  1 to 4

The procedure of Example 1 was repeated to prepare a polymer resin powder, except that the content of nonionic emulsifier and the content of fine particles in Example 1 were changed to the values shown in Table 1 below. The bulk density, the content of coarse particles and the fine particles were measured and are summarized together in Table 1 below.

Comparative Example  5

The same procedure as in Example 1 was repeated except that the nonionic emulsifier was replaced with an anionic emulsifier (Fatty soap) in Example 1 to prepare a polymer resin powder. Similarly, a bulk density, coarse particles and fine The contents of the particles were measured and are summarized together in Table 1 below.

Comparative Example  6

This comparative example corresponds to an experimental example in which circulation and aggregation of fine particles are not performed in the polymer resin powder production process of FIG.

Specifically, the same processes as in Example 1 were repeated to prepare a polymer resin powder, except that the item of &quot; circulation and aggregation of fine particles in polymer resin powder &quot; was not performed in Example 1, The bulk density, the content of coarse particles and the fine particles were measured and are summarized together in Table 1 below.

Comparative Example  7

The same procedure as in Comparative Example 6 was repeated except that the solid content of the polymer latex slurry in Comparative Example 6 was changed to the value shown in Table 1 below to prepare a polymer resin powder. The contents of coarse particles and fine particles were measured and summarized in Table 1 below.

Item Solids content
(wt%) Coagulant Content (parts by weight) Nonion
Emulsifier
Content (parts by weight) Fine particle sol concentration (%) Fine particle content
(Parts by weight) Bulk density Course particle content (%) Fine particles
content(%) Example 1 30 1.0 0.5 5 3 0.34 5.1 0.5 Example 2 35 1.0 0.5 5 3 0.36 6.3 0.1 Example 3 44 1.0 0.5 5 3 0.38 6.0 0.0 Example 4 35 1.0 0.5 5 2 0.36 6.8 0.5 Example 5 35 1.0 0.25 5 3 0.35 7.0 0.8 Example 6 35 1.0 0.5 2.5 3 0.36 6.2 0.2 Example 7 35 1.0 0.5 10 3 0.36 6.5 0.3 Comparative Example 1 35 1.0 0.5 5 5 0.34 8.6 3.3 Comparative Example 2 35 1.0 0.25 5 5 0.34 9.4 3.5 Comparative Example 3 35 1.0 0 5 3 0.33 9.5 4.1 Comparative Example 4 35 1.0 0 5 5 0.33 9.3 4.7 Comparative Example 5 30 1.0 0
(Anion 0.5) 5 3 0.33 9.3 3.9 Comparative Example 6 30 1.0 0 0 0 0.32 8.9 3.8 Comparative Example 7 35 1.0 0 0 0 0.34 9.2 3.2 Comparative Example 8 44 1.0 0 0 0 0.37 9.9 2.1

As shown in Table 1, in Examples 1 to 7 according to the present invention, resin powder having improved powder properties could be confirmed.

On the other hand, in Comparative Examples 1, 2, and 4, when the content of fine particles was large, the results were inferior to those of Comparative Example 7 in which fine particle surface treatment was not performed, to such an extent that the fine particle content increased.

In addition, in the case of Comparative Example 3, when only fine particles were added without adding any nonionic surfactant, it was confirmed that the particle size was increased to not only the fine particles but also the fine particles as compared with Comparative Example 7. The reason for this is that when fine particles are added without additional nonionic emulsifier, relatively large fine particles compared with latex particles are partially surrounded by anions remaining in the aqueous phase, This is because the size of the particles is so large that the movement of the particles is smaller than that of the latex particles under the agglomeration temperature, so that the agglomeration process due to the collision can not be performed.

Also, it was confirmed that the powder properties of Comparative Example 5, which was changed to an anionic emulsifier instead of the nonionic emulsifier and the same amount, were worsened as compared with Comparative Example 7.

In particular, when the amount of the fine particles is excessively increased as in Comparative Example 1, the distribution of the fine particles in the fresh latex is increased, the concentration of the latex around the fine particles decreases, and the amount of aggregation of the fine particles with the fine particles decreases, The possibility of existence of fine particles is increased and powder properties are not improved.

In addition, when the content of fine particles increases, the surface area of the fine particles to be surface treated with a nonionic emulsifier rapidly increases. As a result, the surface treatment of the fine particles is not completely performed and the powder characteristics are deteriorated.

Comparative Example  9

This comparative example corresponds to an experimental example in which the polymer resin powder was prepared by the multi-stage agglomeration and aging process of Fig.

Using the fresh polymer latex used in Example 1, the latex was introduced into a flocculation tank 2 as shown in Fig. 1 at a flow rate of 12 kg / hr, and the diluted sulfuric acid (H2SO4) 2.3 parts by weight were used based on 100 parts by weight of the solid content in the latex.

Water was added to the flocculation tank (2) directly with water, mixed with sulfuric acid in accordance with the solid content of the slurry, and then added in a large amount to adjust the solid content of the polymer latex slurry to 19 wt%.

The retention time in the flocculation tank 2 was 10 minutes on average, the flocculation temperature was 75 ° C, the residence time in the aging tank 6 was 30 minutes, and the aging temperature agglomerated to 85 ° C. The coagulated slurry flows over the chute above the tank 6 and moves to the slurry storage tank 7. The agglomerated and aged slurry was subjected to dehydration (8) and drying (9) to recover the polymer resin powder.

The bulk density, the content of coarse particles and fine particles were measured in the same manner as in Example 1, and the results are summarized in Table 2 below.

Comparative Example  10

The polymer resin powder was recovered in the same manner as in Example 2, except that the apparatus of Fig. 2 used in the production of the polymer resin powder in Example 2 was replaced by the apparatus of Fig.

The bulk density, the content of coarse particles and the fine particles were measured in the same manner as in Example 2, and the results are summarized in Table 2 below.

Comparative Example  11

The polymeric resin powder was recovered in the same manner as in Comparative Example 10, except that 5 parts by weight of the fine particles added in Comparative Example 10 was replaced by 3 parts by weight.

The bulk density and the content of coarse particles and fine particles were measured in the same manner as in Comparative Example 10, and are summarized in Table 2 below.

Comparative Example  12

The polymeric resin powder was recovered in the same manner as in Comparative Example 10, except that the water content in the coagulation tank 2 was reduced and the solid content in the coagulation tank 2 was adjusted from 19 wt% to 30 wt% .

As a result, the viscosity of the agglomerated tank increased sharply, and the agglomerated slurry became a lump, and the viscosity increased sharply, which made the state impossible to transport. As a result, it could not be aged and the polymer resin powder could not be recovered.

Item Solids content
(wt%) Coagulant Content (parts by weight) Nonionic emulsifier content (parts by weight) Fine particles
Sol concentration
(%) Fine particle content (parts by weight) Bulk density Course particle content (%) Fine particle content (%) Comparative Example 9 19 2.3 0 0 0 0.29 16.8 6.2 Comparative Example 10 19 2.3 0.5 5 3 0.30 15.3 5.5 Comparative Example 11 19 2.3 0.5 5 5 0.29 16.7 5.3 Comparative Example 12 30 2.3 0.5 5 3 No cohesion - Viscosity increase

As shown in Table 2, Comparative Example 9, in which a resin powder was separately prepared through agglomeration and aging processes through a multi-tank agglomeration process of an existing tank, was compared with Comparative Example 6 of Table 1 It was confirmed that the comparative powder characteristics were poor. Since the water content in the flocculation tank 2 is large and the latex particle distance in the same condition is far away, the probability of collision between the latex particles is greatly lowered, and the concentration distribution of the flocculant in the tank is not uniform, Respectively.

In addition, when the temperature in the tank was increased through the steam, the temperature distribution was widened, and it was confirmed that the powder had a high solid content and a poor powder characteristic as compared with that passing through the agglomeration aging device used in the present invention.

In order to overcome this, the water content in Comparative Example 11 was adjusted in the same manner as in Comparative Example 6, and as a result, the viscosity in the flocculation tank 2 rapidly increased and the operation was impossible. In the case of the agglomerating and aging apparatus 100 shown in FIG. 3, which simultaneously exhibits agglomeration and aging in a high solid content state, the pin in the barrel and the agitator in the barrel can crush and transport a slurry having a high viscosity, In the case of tank aggregation, the agitation force is remarkably reduced when the viscosity is increased.

As a result, as shown in Tables 1 and 2, when the fine particle sol treated with the non-ionic emulsifier on the fine particle surface was mixed with the fresh polymer latex, The amount of the nonionic emulsifier is preferably 0.2 to 0.5 parts by weight based on 100 parts by weight of the total amount of the polymer latex. On the other hand, it was confirmed that the amount of water introduced into the fine particle mixed solution was very small as compared with the water content in the whole latex during agglomeration.

&Lt; 1 >
1: latex storage tank 2: flocculation tank
3: steam 4: coagulant aqueous solution
5: latex transfer line 6: aging tank
7: Slurry storage tank 9: Dehydrator
11, 13: Cyclone
2 and 3,
Aggregation combined aging device (2: corresponding to reactor 100 in FIG. 3)
Fresh latex (19)
Slurry storage tanks (5)
Centrifugal dehydrators (6)
Waste water (7)
Fluid bed dryer (8)
Cyclone 1 (9)
Genuine particle (10)
Cyclone 2 (12)
The fine particle recovery line (13)
The fine particle mixed solution tank (14)
Inline Mixer (16)
Nonionic emulsifiers (17)
Static Mixer (18)
The latex 20, in which the surface-treated fine particle solution is mixed,

Claims (13)

Anion emulsion polymerized fresh latex comprising a hollow reaction tube, at least one barrel pin protruding from the inner wall of the reaction tube toward the inside of the reaction tube, a rotation axis extending along the longitudinal center axis of the reaction tube, And at least one stirrer protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, wherein the at least one stirrer is a non-continuous screw, and the coagulant supply pipe and the steam supply pipe are provided at a lower portion of the device, To produce a coagulated aged slurry,
Dehydrating the coagulated aged slurry through a centrifugal dehydrator,
Air-drying the slurry dewatered in the centrifugal dehydrator while sequentially passing the slurry through the first cyclone and the second cyclone, and separating fine particles having a weight average particle diameter of 75 μm or less;
Passing the aqueous dispersion of the separated fine particles through an inline mixer and continuously treating the surface with a nonionic emulsifier in the inline mixer to prepare a surface treated fine particle containing solution,
And discharging the surface-treated fine particle-containing solution as a mixture with the anionic emulsion polymerization fresh latex through a static mixer,
And the discharged mixture is introduced into the agglomerating and aging apparatus. delete The method according to claim 1,
The step of preparing the surface-treated fine particle-containing solution is characterized in that a sol type solution is obtained by using 0.2 to 0.5 part by weight of a nonionic surfactant based on 100 parts by weight of the anionic emulsion polymerization fresh latex (Method for producing polymeric resin powder). The method according to claim 1,
Wherein the mixture to be fed to the aggregation and aging apparatus is not more than 4 parts by weight of the surface-treated fine particle-containing solution based on 100 parts by weight of the anionic emulsion polymerization fresh latex. The method according to claim 1,
Wherein the step of preparing the agglomerated aged slurry is carried out at a temperature of 60 to 98 DEG C for a retention time of 30 seconds to 5 minutes under a steam load. The method according to claim 1,
The step of preparing the agglomerated aged slurry is performed by using 0.5 to 1.5 parts by weight of at least one flocculant selected from hydrochloric acid, sulfuric acid, phosphoric acid, sulfate and calcium salt based on 100 parts by weight of anionic emulsion polymerization fresh latex By weight of the polymer resin powder. The method according to claim 1,
Wherein the solid content of the anionic emulsion polymerization fresh latex is 30 to 60 wt%. The method according to claim 1,
The anionic emulsion polymerization fresh latex may be prepared by reacting an anionic emulsion polymerization latex, an alkyl acrylate-acrylonitrile copolymer latex, an acrylonitrile-butadiene copolymer latex, a styrene-butadiene copolymer latex, an alkyl acrylate polymer latex, an alkyl methacrylate polymer latex, Butadiene-styrene copolymer latex, an acrylonitrile-butadiene-styrene copolymer latex, an acrylonitrile-alkyl acrylate-styrene copolymer latex, an alkyl methacrylate-butadiene-styrene copolymer latex, and an alkyl acrylate-alkyl methacrylate A copolymer latex, and a copolymer latex. delete An apparatus for producing a coagulated aged slurry in an anionic emulsion polymerization fresh latex, comprising: a hollow reaction tube; at least one barrel pin protruding from the inner wall of the reaction tube toward the inside of the reaction tube; And at least one stirrer protruding from the outer surface of the rotating shaft toward the inner wall of the reaction tube, wherein the at least one stirrer is a non-continuous screw, and the coagulant and the steam An agglomerating and aging device equipped with a supply pipe;
A centrifugal dehydrator for dehydrating the coagulated agglomerated slurry and separating the dehydrated slurry;
A first cyclone and a second cyclone for air-drying the dehydrated slurry to separate fine particles having a weight average particle diameter of 75 탆 or less; And
An inline mixer for surface-treating the aqueous dispersion of fine particles separated from the second cyclone with a nonionic emulsifier to provide a surface-treated fine particle-containing solution;
A stoichiometric mixer for discharging the surface treated fine particle containing solution as a mixture with the anionic emulsion polymerization fresh latex; Lt; / RTI &gt;
And the mixture discharged from the stemic mixer is introduced into the agglomerating and aging device. delete 11. The method of claim 10,
And an agglomerated slurry storage tank is provided between the agglomeration aging device and the centrifugal dehydrator. 11. The method of claim 10,
And a fine particle mixed solution storage tank is provided between the second cyclone and the inline mixer.

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