JPH08109208A - Method for producing seed particles for emulsion polymerization and continuous multistage emulsion polymerization method - Google Patents

Abstract

(57) [Summary] [Objective] In a continuous multi-stage emulsion polymerization reaction, a means capable of generating a sufficient number of seed particles having a high polymerization rate, and further, using heel seed particles, a desired particle size distribution with a narrow particle size distribution is desired. A means by which a polymer having a polymerization rate can be obtained is provided. [Constitution] In the continuous multistage emulsion polymerization apparatus, emulsion polymerization is carried out in the first double cylindrical reactor 51 in a state where Taylor vortices are generated, and a sufficient number of seed particles having a high polymerization rate are produced. It Further, the second double cylindrical reactor 6
In 7, the emulsion polymerization is carried out with a sufficient number of seed particles as cores in a state where Taylor vortices are generated, and the desired particle size distribution is narrowed without causing separation of monomers or adhesion of aggregates. A polymer having a degree of polymerization is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to emulsion polymerization for obtaining seed particles by reacting a part of a polymer raw material containing a monomer in a pre-reaction in a continuous multi-stage emulsion polymerization in a fluidized state utilizing Taylor vortex. The present invention relates to a method for producing seed particles and a continuous multi-stage emulsion polymerization method for continuously polymerizing the seed particles together with the remaining polymer raw material to obtain final polymer particles.

[0002]

BACKGROUND OF THE INVENTION Emulsion polymerization is generally employed to produce polymer particles having a relatively small particle size. The polymer particles such as synthetic rubber latex, vinyl acetate latex, and acrylic latex are used as rubber product intermediates, paint binders, adhesives, and various control agents for controlling viscosity, surface activity, dispersibility, and the like. It's being used.

As a method for industrially producing a polymer by emulsion polymerization, a batch method and a continuous method have hitherto been known, but at present, the batch method is the mainstream. This is because the continuous method is more difficult to control the emulsified state than the batch method, which causes problems such as separation of monomers and generation of aggregates in the reaction step. Further, the continuous method has a drawback that it is difficult to obtain polymer particles having a desired particle size and degree of polymerization.

However, emulsion polymerization by the continuous method is
Compared with the batch method, there is an advantage that a large amount of polymer particles can be obtained in a short time. Therefore, if the above-mentioned drawbacks are improved, it is possible to industrially carry out the continuous polymerization method, and it is considered that its industrial merit is immeasurable.

As a continuous emulsion polymerization method, a tubular reactor,
A method using a continuous tank reactor, a loop reactor or the like has been conventionally known. Here, the continuous emulsion polymerization method using a tubular reactor, emulsion polymerization in the reaction tube while continuously flowing the polymer raw material solution containing the monomer into the reaction tube having a uniform passage cross-section and inner diameter. It is a method of making it do. A continuous emulsion polymerization method using a continuous tank type reactor is such that reaction tanks having a stirring means are connected in multiple stages in series, the polymer raw material liquid is sequentially and continuously supplied to each reaction tank, and the emulsion polymerization is sequentially performed in each reaction tank. It is a method of making it do. Further, the continuous emulsion polymerization method using a loop type reactor, a polymer raw material liquid is continuously supplied to a loop-shaped reaction tube, the emulsion polymerization is carried out while circulating the polymer raw material liquid in the reaction tube. At the same time, the reaction liquid containing the polymer is guided to the outside of the reaction tube.

[0006]

Here, in the method using the tubular reactor, the larger the tube length / tube diameter ratio (L / D ratio), the more the agglomerates adhere to the inner surface of the reactor, and especially the solid state. As soon as the fraction is high, agglomerates are generated which accumulate on the inner surface of the reactor. Therefore, bubbles are mixed in the polymer raw material liquid, and the supply of the polymer raw material liquid is hindered. Further, when a large amount of aggregates are generated, it is necessary to stop the apparatus frequently to remove the aggregates, which is wasteful. It should be noted that when the L / D ratio is reduced, the amount of aggregates is reduced, but there is a problem that the separation of the monomer is likely to occur. Furthermore, in order to secure the reaction time, the flow of the raw material liquid must be slowed down, which causes a problem that there is no great difference from the batch method.

The method using a continuous tank reactor has few agglomerates on the inner surface of the reactor, no bubbles are mixed into the polymer raw material liquid, and the polymer raw material liquid is easily stirred. However, since the raw material liquids are sequentially supplied to the respective reaction tanks to carry out the polymerization, variations in residence time of individual raw materials increase,
Therefore, although polymer particles having a small particle size can be obtained,
At the same time, polymer particles having a large particle diameter are also produced, and the particle diameter distribution or molecular weight distribution of the finally obtained polymer particles becomes wide, and it is difficult to obtain a desired degree of polymerization.

The method using a loop reactor has a problem that polymer particles having a small particle size cannot be obtained. Further, there is a problem that agglomerates are likely to be accumulated on the inner surface of the reactor, so that air bubbles are easily mixed in the raw material liquid. Further, there is a problem that it is difficult to stir the raw material liquid.

In order to solve these problems, a pre-reactor is installed, and the first-stage reaction (pre-reaction) is performed in the pre-reactor to generate seed particles (nuclear particles). After that, a continuous multistage emulsion polymerization method in which a monomer is further added to the seed particles to grow the particles (hereinafter, this is referred to as a seed polymerization method)
Is proposed. More specifically, in a general continuous polymerization, reaction raw materials such as a monomer, an emulsifier, an initiator and a chain transfer agent are supplied to a continuous reactor together with raw water,
At this time, the phenomenon that the polymerization rate, molecular weight, particle size, etc. of the emulsion liquid taken out after the reaction changes periodically with time, so-called vibration phenomenon easily occurs,
Therefore, there is a problem that uniform and stable quality polymer particles cannot be obtained. The seed polymerization method was developed in order to solve this problem.

However, the seed polymerization method is basically an effective method in which the above-mentioned vibration phenomenon can be avoided and the polymer raw material can be polymerized at a concentration of polymer particles produced as high as possible. When the degree of polymerization in the one-step reaction is low and the number of seed particles generated is small, the above effect is not sufficiently obtained. That is, in the seed polymerization method, the polymerization rate in the first-step reaction is high, and the number of seed particles that are generated is required to be sufficiently large. If this condition is not satisfied, separation of monomers and generation of aggregates are eliminated. However, the improvement effect is insufficient. Thus, all of the pre-reactors used in the conventional seed polymerization method have a problem that it is difficult to secure a sufficient number of seed particles at a high polymerization rate.

The present invention has been made in order to solve the above-mentioned conventional problems, in which a pre-reactor is installed to supply a minimum amount of raw material liquid necessary and sufficient for generating seed particles. In a multi-stage continuous emulsion polymerization method in which seed particles are generated in the first-stage reaction and most of the remaining raw material liquid is supplied to the second-stage reactor to grow the particles, a high polymerization rate and a sufficient number in the first-stage reaction are used. It is an object of the present invention to provide a means capable of obtaining seed particles of Furthermore, by using the above seed particles, a final polymer having a narrow particle size distribution and a desired degree of polymerization can be obtained without causing problems such as separation of monomers during the reaction or adhesion of aggregates to the inner surface of the reactor. The purpose is to provide means by which particles can be obtained.

[0012]

[Means for Solving the Problem] In order to obtain a high polymerization rate and a sufficient number of seed particles in the first-step reaction, the inventors of the present invention need a reaction product in the first-step reaction and a sufficient amount. We considered that it is indispensable to make a mixed state and to generate a flow state close to the extruding flow, and we studied a method that can realize such a mixed state and a flow state.
In the process, the present inventors have come to the idea that the above conditions will be satisfied if a double cylinder having a coaxial outer cylinder and inner cylinder is used as the pre-reactor. That is, the inventors have come up with a method of utilizing a unique flow phenomenon that occurs in a fluid put between both cylinders when at least one cylinder of the double cylinder body is rotated around its axis. The flow of fluid accompanying the rotation of such a double cylinder is various, such as a laminar flow in which the entire fluid draws a circular orbit around the axis, a flow that produces a Taylor vortex, and a turbulent flow. As a result of repeating operations such as performing continuous emulsion polymerization using these various flows, the inventors can realize the mixed state and the flow state close to the extruded flow only when the flow produces a Taylor vortex. I found such a fact. The present invention has been completed based on such knowledge.

Therefore, in order to solve the above-mentioned problems, the present invention provides a coaxial polymer having an outer cylinder and an inner cylinder which share one axis extending in a direction intersecting the horizontal direction with a part of the polymer raw material liquid. A pre-reactor having a double-cylindrical structure is continuously supplied from one end side thereof, and at least one cylinder of the double-cylindrical body is rotated around an axis to generate Taylor vortices in the polymer raw material liquid while The basic characteristic is that emulsion polymerization as a one-step reaction is carried out, and a reaction liquid containing seed particles for continuous multi-step emulsion polymerization is taken out from the other end side of the double cylinder. Furthermore, the basic feature is that after this, the reaction liquid containing the seed particles is continuously polymerized with the remaining polymer raw material liquid to obtain a final polymer.

Thus, the first invention provides a coaxial double-cylindrical reactor having an outer cylinder and an inner cylinder which share one axis extending in a direction intersecting with a horizontal plane, and comprises a polymer containing a monomer. A part of the raw material liquid is continuously supplied to the annular space between the outer cylinder and the inner cylinder of the double cylindrical reactor from one end side in the axial direction, while at least one cylinder is rotated around the axis. Then, a Taylor vortex is generated in the annular space portion, and in the polymer raw material liquid in the annular space portion, an emulsion polymerization reaction is caused in a state where the Taylor vortex is generated to generate seed particles for continuous multistage emulsion polymerization. The method for producing seed particles for emulsion polymerization is characterized in that the reaction liquid containing the generated seed particles is guided to the outside from the other end side in the axial direction of the double cylindrical reactor to continuously obtain seed particles. Provide a way.

In the second invention, the Taylor number is 310 to 84.
The method for producing seed particles for emulsion polymerization according to the first invention is characterized in that the outer cylinder or the inner cylinder is rotated so as to be zero.

In a third aspect of the invention, the polymer raw material liquid is supplied from the lower end side of the double cylindrical reactor, and the reaction liquid containing seed particles is guided to the outside from the upper end side of the double cylindrical reactor. A method for producing seed particles for emulsion polymerization according to the first or second invention is provided.

In a fourth aspect of the present invention, a jacket is provided on the outer surface of the outer cylinder, and a heating medium is supplied to the jacket to control the temperature of the polymer raw material liquid in the annular space to cause an emulsion polymerization reaction. The first to
A method for producing seed particles for emulsion polymerization according to any one of the third invention is provided.

In a fifth aspect of the invention, seed particles produced by the method according to any one of the first to third aspects of the invention and a polymer raw material liquid containing a monomer are supplied to a continuous reaction apparatus. There is provided a continuous multi-stage emulsion polymerization method characterized by performing an emulsion polymerization reaction using seed particles as a core to obtain a final polymer.

A sixth aspect of the present invention uses, as a continuous reactor, a coaxial double cylinder type reactor having an outer cylinder and an inner cylinder which share one axis extending in a direction intersecting with a horizontal plane, and uses a coaxial double cylinder type reactor. The combined raw material liquid is continuously supplied to the annular space portion between the outer cylinder and the inner cylinder of the double cylindrical reactor from one end side in the axial direction, while at least one cylinder is rotated around the axis. To generate a Taylor vortex in the annular space, the seed particles and the polymer raw material liquid in the annular space, to cause an emulsion polymerization reaction in the state of Taylor vortex to produce a final polymer. The reaction solution containing the final polymer thus produced is introduced to the outside from the other end in the axial direction of the double cylindrical reactor so that the final polymer is continuously obtained. And continuous multistage emulsion polymerization method according to the fifth invention To provide.

In the double cylindrical reactor for producing seed particles, the polymer raw material liquid containing a monomer is supplied from either the upper end side or the lower end side of the double cylindrical reactor. be able to. Here, when the polymer raw material liquid is supplied from the upper end side, the reaction liquid containing seed particles is taken out from the lower end side, and when the polymer raw material liquid is supplied from the lower end side, the reaction liquid is taken out from the upper end side. In addition, when a double cylindrical reactor is used as a continuous reaction device for the second-stage reaction, the same is basically the case. In this case, from the viewpoint of minimizing the amount of aggregates, the reaction liquid containing the seed particles and the polymer raw material liquid containing the monomer are supplied from the lower end side, and the reaction liquid containing the final polymer is supplied. Is preferably guided from the upper end side to the outside.

In the double-cylindrical reactor for producing seed particles, the outer cylinder has a cylindrical inner surface, and the reaction vessel is installed so that its axis is oriented in a direction intersecting the horizontal direction, The inner cylinder has an outer surface forming a double cylinder portion coaxial with the inner surface of the outer cylinder and has a rotatable structure in which at least the bottom surface is closed, and rotation means for rotating the inner cylinder about its axis is provided, On the bottom surface of the outer cylinder (reaction vessel body), a polymer raw material liquid supply port is provided at a position corresponding to the bottom surface of the inner cylinder. It is preferable that a vortex is formed and emulsion polymerization is performed in such a state. In addition, when a double cylindrical reactor is used as a continuous reaction device for the second-stage reaction, the same is basically the case.

In the double cylinder type reactor for producing seed particles, the upper surface of the inner cylinder is also closed and the outer cylinder is closed.
The upper surface of the (reaction vessel body) is provided with an outlet for the reaction solution containing seed particles at a position corresponding to the upper surface of the inner cylinder, and a plurality of outer surfaces of the outer cylinder (reactor body) are arranged in the advancing direction of the raw material solution. It is preferable that a jacket for heating and a jacket for cooling are provided separately in the regions. In addition, when a double cylindrical reactor is used as a continuous reaction device for the second-stage reaction, the same is basically the case.

The monomer used in the present invention is an ethylenically unsaturated monomer having radical polymerizability, and suitable examples thereof include unsaturated monomers such as monovinyl aromatic monomers, acrylic acid and methacrylic acid. Carboxylic acids, their ester monomers, vinyl ester monomers, vinyl ether monomers, diolefin monomers, monoolefin monomers, halogenated olefin monomers, polyvinyl monomers,
Examples thereof include polyfunctional monomers (excluding diolefin monomers and polyvinyl monomers). These may be used alone or in combination of two or more.

Examples of the monovinyl aromatic monomer include monovinyl aromatic compounds represented by the following formula (1). In the formula (1), R ¹ is a hydrogen atom, a methyl group or a halogen atom, and R ² is a hydrogen atom, a lower alkyl group (having 1 to 6 carbon atoms), a halogen atom, an alkoxy group, an amino group or a nitro group. A group, a carboxyl group or a sulfonic acid group. Further, in the formula (1), n is an integer of 1 to 5, and when n is 2 to 5, it is not necessary that each R ² be the same. Specific examples of such monovinyl aromatic compounds include styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-, m-, p-chlorostyrene, p-ethylstyrene, sodium styrenesulfonate and the like. These may be used alone or in combination of two or more.

[0025]

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As unsaturated carboxylic acids such as acrylic acid and methacrylic acid, or ester monomers thereof,
For example, an acrylic monomer represented by the following formula (2) can be given. In the formula (2), R ³ is a hydrogen atom or a methyl group, and R ⁴ is a hydrogen atom, a hydrocarbon group having 12 or less carbon atoms, a hydroxyalkyl group, a vinyl ester group, or an aminoalkyl group. Specific examples of the acrylic monomer include acrylic acid, methacrylic acid, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, and methacrylic acid. Acid-2-ethylhexyl, 2-hydroxyethyl acrylate, 3-hydroxybutyl acrylate,
4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 3-aminopropyl acrylate, 3-diethylaminopropyl acrylate and the like. These may be used alone or in combination of two or more.

[0027]

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Examples of vinyl ester monomers include vinyl esters represented by the following formula (3). In the formula (3), R ⁵ is a hydrogen atom or a lower alkyl group (having 1 to 6 carbon atoms). Specific examples of such vinyl ester are vinyl formate, vinyl acetate, vinyl propionate and the like. These are used individually,
Alternatively, they may be used in combination of two or more.

[0029]

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Examples of vinyl ether monomers include vinyl ethers represented by the following formula (4). In the formula (4), R ⁶ is a monovalent hydrocarbon group having up to 12 carbon atoms. Specific examples of such vinyl ethers include vinyl methyl ether, vinyl ethyl ether, vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like. These may be used alone or in combination of two or more.

[0031]

[Chemical 4]

Examples of diolefin monomers include the following:
Diolefins represented by the formula (5) can be mentioned.
In the formula (5), R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom, a lower alkyl group (having 1 to 6 carbon atoms) or a halogen atom. Specific examples of such diolefins are, for example, butadiene, isoprene, chloroprene and the like. These may be used independently or may be used in combination of two or more kinds.

[0033]

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Examples of the mono-olefin monomer include mono-olefins represented by the following formula (6). In the formula (6), R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a lower alkyl group (having 1 to 6 carbon atoms).
Specific examples of such mono-olefins include, for example, ethylene,
Propylene, butene-1, pentene-1, 4-methylpentene-1 and the like. These may be used alone or in combination of two or more.

[0035]

[Chemical 6]

Examples of the halogenated olefin monomer include vinyl chloride and vinylden chloride. These may be used alone or in combination of two or more.

Examples of polyvinyl monomers include divinylbenzene, diallyl phthalate and triallyl cyanurate. These may be used alone or in combination of two or more.

The above-mentioned polyfunctional monomer is a compound having two or more radically polymerizable ethylenically unsaturated groups in the molecule and is a compound other than a diolefin monomer and a polyvinyl monomer. Is. Specific examples thereof include ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate,
1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,6
-Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate,
Pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, glycerol diacrylate, glycerol dimethacrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethyl Ethane dimethacrylate, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylethane trimethacrylate, 1,1,1
-Trishydroxymethylpropane diacrylate,
Examples thereof include polymerizable unsaturated monocarboxylic acid esters of polyhydric alcohols such as 1,1,1-trishydroxymethylpropane dimethacrylate. Alternatively, a polymerizable unsaturated alcohol ester of a polybasic acid such as diallyl terephthalate, diallyl phthalate and triallyl trimellitate may be used. Furthermore, such as divinylbenzene,
Aromatic compounds substituted with two or more vinyl groups are mentioned. In addition, addition reaction products of epoxy group-containing ethylenically unsaturated monomers such as glycidyl acrylate and glycidyl methacrylate with carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid and maleic acid. And so on. These may be used alone or in combination of two or more.

In the present invention, the emulsifier used for emulsion polymerization is, for example, a nonionic surfactant, anionic surfactant, cationic surfactant, amphoteric surfactant, or the like. These may be either reactive or non-reactive. These may be used alone or in combination of two or more.

In the polymerization initiator used in the present invention, water-soluble ones include, for example, azo polymerization initiators,
Examples thereof include peroxide type polymerization initiators. Also,
Any oil-soluble substance may be used. These may be used alone or in combination of two or more.

The continuous emulsion polymerization method according to the present invention is a seed polymerization method in which seed particles for polymerization are grown. For example, seed particles for polymerization (nucleus particles) obtained by emulsion polymerization of a part of a polymer raw material in advance. ) And the polymer raw material liquid are emulsion polymerized. In particular, emulsion polymerization by the seed polymerization method has an advantage that particles can be monodispersed. That is, by using the seed polymerization method, the particle size of the final polymer is further reduced and the particle size distribution is narrowed. This is because it is possible to prevent the raw material monomer from being quickly absorbed by the seed particles, and to suppress the generation of new particles in the aqueous phase of the dispersed soot.

In the present invention, the polymer raw material liquid is prepared in an appropriate manner using the above-mentioned monomers, emulsifiers, polymerization initiators, and other chemicals used as needed in an appropriate ratio. And seed particles (seed emulsion),
It is produced by emulsion-polymerizing a part of the polymer raw material liquid in a state where Taylor vortices are generated using a double cylindrical reactor. After this, the seed polymer and the remaining polymer raw material are mixed and emulsion-polymerized to produce a final polymer. This mixing may be carried out in advance before they are fed to the continuous reactor for carrying out the second stage reaction, or they may be fed separately to the continuous reactor and carried out in the reactor.

The seed particles (seed emulsion) are, for example, an aqueous monomer solution having a monomer concentration of about 10% by weight or less,
Double cylinder of initiator solution of arbitrary concentration (if the initiator is water-soluble, its aqueous solution, if it is oil-soluble, its organic solvent solution), and (if necessary) an emulsifier for stabilizing particle formation It is prepared by feeding it to a mold reactor, raising the temperature to an appropriate initiator decomposition temperature, and emulsion polymerizing these.

Here, the seed particles are, for example, non-crosslinked polymer particles and crosslinked polymer particles obtained by emulsion polymerization. Such seed particles may be used alone or in combination of two or more. The nonvolatile content of the polymer raw material liquid is not particularly limited, but is preferably 55% by weight or less, for example. This is because it suppresses a rapid temperature rise of the reaction solution due to the heat of reaction.

In the double cylinder type reactor for producing seed particles, the polymer raw material liquid containing the monomer is continuously supplied to the annular space between the coaxial outer cylinder and inner cylinder. It As the continuous supply method, for example, a method of supplying using various pumps, a method of supplying potential energy from a tank installed above the double cylindrical reactor, or the like is adopted. Such a double cylindrical reactor is
The central axis (axis) needs to be installed so as to extend in a direction intersecting with the horizontal direction, and normally the central axis is installed so as to extend in the vertical direction. This is because when the double cylindrical reactor is installed so that its central axis extends in the horizontal direction, Taylor vortices do not occur. The supply port of the polymer raw material liquid to the double-cylindrical reactor and the outlet of the reaction liquid from the double-cylindrical reactor are basically provided anywhere in the double-cylindrical reactor. Although good, a double-cylindrical reactor is usually provided with a supply port at one end and an extraction port at the other end. In this case, when the upper end side is the supply port, there is an advantage that the unreacted monomer and the floating aggregates can be easily removed, and when the lower end side is the supply port, the flotation and separation of the monomer are less likely to occur and the aggregates are There is an advantage that it is less likely to occur. The supply rate (flow rate) of the polymer raw material liquid, the volume of the double cylindrical reactor (volume of the annular space portion), and the polymerization time (residence time) are related to each other. Usually, the volume of a double-cylindrical reactor cannot often be changed once the double-cylindrical reactor is installed. The polymerization time is also set to an appropriate time depending on the raw material of the polymer. Therefore, it is general to appropriately set the supply rate of the polymer raw material liquid from the volume of the double cylindrical reactor and the polymerization time, but of course, the present invention is not limited to such a method.

In emulsion polymerization for producing seed particles, the lower limit of the polymerization time is usually several minutes to the upper limit of several hours, preferably 20 to 60 minutes. The polymerization temperature is usually from room temperature to about 95 ° C, and is preferably determined by the radical generation temperature of the polymerization initiator used (for example, 50 to 83 ° C). In the present invention, in the emulsion polymerization for producing seed particles, the polymer raw material liquid contained in the annular space between the outer cylinder and the inner cylinder of the double cylindrical reactor forms a Taylor vortex. Done in the state. The Taylor vortex is formed when at least one of the outer cylinder and the inner cylinder of the double cylindrical reactor is rotating around its central axis and the angular velocity of the rotation exceeds a certain critical value. To be done. Only the inner cylinder may be rotated, only the outer cylinder may be rotated, or both cylinders may be rotated. The rotation direction may be clockwise (so-called clockwise) or counterclockwise (so-called counterclockwise). In practice, since the outer cylinder often doubles as the reaction container body, it is often installed in a fixed form without rotating, and only the inner cylinder is often rotatable.

In the double cylinder type reactor for producing seed particles, the inner cylinder may have a cylindrical outer surface. For example, a cylindrical object having such a shape may be used,
The inside may be a void. If the inside is a void,
Facilities for performing thermal treatment (for example, heating and cooling) can be provided in the space inside thereof. Since no Taylor vortex is generated inside the inner cylinder, at least the bottom surface of the inner cylinder is preferably closed so that the polymer raw material liquid does not enter the inner cylinder. The upper end surface of the inner cylinder may be closed if necessary. For example, when the liquid level is designed to come only below the upper end of the inner cylinder (that is, when the outlet of the double cylindrical reactor is provided to some extent below the upper end of the inner cylinder). ), Or when the reaction liquid enters the inside of the inner cylinder and is taken out to the outside, it is not inconvenient even if the upper end surface of the inner cylinder is open. If the outer cylinder extends above the inner cylinder and a reaction solution outlet is provided at that location, the upper end surface of the inner cylinder is also blocked so that the reaction solution does not enter the internal space of the inner cylinder. Is preferable. The material forming the inner cylinder is preferably a material that does not allow or hardly penetrates a substance, such as metal, glass, or ceramic. When the inner cylinder is rotated about its central axis, it is preferable to provide the rotating shaft integrally with the inner cylinder. The rotating shaft is rotatably supported by bearings on the upper and lower surfaces of the outer cylinder fixedly installed,
It is preferably attached to rotating means such as a motor. The rotating shaft of the motor may be integrated with the inner cylinder.

The inner cylinder and the outer cylinder may be cylinders in a mathematically strict sense, but the cylinders are not limited to these and may be cylinders with an accuracy of a degree usually used in the industrial field. The outer cylinder need only have a cylindrical inner surface and need not be cylindrical on the outside. The outer cylinder usually doubles as the inner surface of the reactor body, and the lower end surface (bottom surface) is closed so that the polymer raw material liquid can be put inside, and the polymer raw material liquid supply port is provided on this bottom surface. Is provided. In this case, the supply port is preferably provided at a position corresponding to the bottom surface of the inner cylinder on the bottom surface of the outer cylinder. In this way, the polymer raw material liquid can be continuously supplied from the supply port so as to contact the bottom surface of the inner cylinder, and the polymer raw material liquid can be supplied without breaking Taylor vortices generated between the both cylinders. be able to. In order to obtain such an effect, the supply port is preferably provided at a position within the radius of the inner cylinder from the center of the bottom face of the outer cylinder, and more preferably at the center of the bottom face of the outer cylinder. The material forming the outer cylinder is preferably a material that is completely impermeable to substances, such as metal, glass, or ceramic. From the viewpoint of taking out the reaction liquid without breaking the Taylor vortex, it is preferable that the take-out port is provided so as to face the upper end surface (upper surface) of the outer cylinder to the upper surface of the inner cylinder.

The condition for producing the Taylor vortex is expressed using the value of the dimensionless number Ta called the Taylor number as an index. The Ta condition for producing the Taylor vortex is preferably Tacr (laminar flow region) ≦ Ta ≦ 2000, and more preferably 30 ≦ Ta ≦ 800. Further, 310 ≦ Ta ≦ 840 is particularly preferable for producing seed particles. Here, Tacr is the critical Taylor number, which is the lower limit of the Taylor vortex in a homogeneous system. If Ta is smaller than Tacr, Taylor vortex may not be generated, and if it is smaller than 30, sufficient agitation that may prevent separation of monomers may not be performed. When Ta exceeds 2000, Taylor vortex is disturbed and it is no different from the stirring tank. In the case where the double-cylindrical reactor is installed so that its central axis faces the vertical direction, the outer cylinder is fixed without rotating, and the inner cylinder rotates, Ta is represented by the following formula. Be done. _{Ta = (ω · R 1 ·} b / ν) · (b / R 1) 1/2 , however, b: radius difference between both cylinders of the double cylinder type reactor
[cm] R ₁ : radius of inner cylinder [cm] ν: kinematic viscosity [cm ² / sec] ω: angular velocity of inner cylinder [1 / sec] where b, R ₁ , ν and ω in the above equation The values are appropriately set independently of each other as long as the value of Ta falls within the above numerical range, and there is no particular limitation. However, b / R ₁ is preferably 0.4 to 0.8, more preferably 0.55 to 0.6.
It is 5.

When the polymer raw material liquid is polymerized in a fluid state forming a Taylor vortex, heating and / or heating from either or both of the outer cylinder and the inner cylinder of the double cylinder type reactor.
Alternatively, cooling may be performed appropriately. Thereby, the efficiency of heat exchange is increased, and the double cylindrical reactor can be made compact and / or the throughput can be improved. For example, when heating is performed from the outer cylinder, a jacket for heating or cooling is installed outside the outer cylinder. This jacket is installed in multiple areas in the direction that intersects the horizontal direction, and each can be used for heating and cooling as needed.
It may be a cooling jacket. When jackets are installed in a plurality of areas, the jackets in each stage may be used independently of each other.

In the present invention, "continuous" is not limited to the meaning of "continuously and gradually", but also includes the meaning of "intermittent". In the case of intermittent supply, it is preferable to supply the raw material liquid corresponding to one donut-shaped flow described later.

The above description of the double cylindrical reactor for producing seed particles is basically applied to the case where the double cylindrical reactor is used as the continuous reactor for the second stage reaction. apply.

[0053]

[Operation] A Taylor vortex is generated in the polymer raw material liquid continuously supplied to the annular space between both cylinders of the double cylinder type reactor for generating seed particles, so that a complete mixing flow and an extrusion flow are generated. Both happen. As shown in FIG.
The polymer raw material liquid 9 flows in the annular space between the outer cylinder 1 and the inner cylinder 2 in the shape of a stack of donuts surrounding the inner cylinder 2. This flow has the same rotation direction around the central axis 6, but in each donut, when viewed in a cross section including the central axis 6 (both ends in FIG. 3), the donuts are vertically opposite to each other. It also has such a rotation (arrow R). This is a perfect mixing flow. This allows
The polymer raw material liquid is sufficiently agitated to suppress the separation and floating of the monomer, and to prevent or suppress the generation of aggregates and their adhesion / accumulation on the reactor wall.

By continuously supplying the polymer raw material liquid 9 to the annular space between both cylinders of the double cylinder type reactor from one end side thereof, the flow of the original donut stacked form is not disturbed. As it is, it shifts to the other end of the double cylindrical reactor. This is the extrusion flow (arrow M or N). A new donut-shaped flow occurs at one end of the supply side. Due to such a phenomenon, the polymerization conditions in the double cylindrical reactor become more uniform than those in the conventional reactor. Due to the characteristics of both these perfectly mixed and extruded flows,
The amount of treatment can be increased and / or the apparatus can be made compact as compared with the conventional reaction in a stirring tank.

Thus, according to the first aspect of the present invention, in the double cylindrical reactor for producing seed particles, a state where Taylor vortices are generated, that is, a state where a perfect mixed flow and an extruded flow are generated. Then, emulsion polymerization of the polymer raw material liquid containing the monomer is performed, and the raw material liquid containing the seed particles is generated.

According to the second invention, basically the same operation as that of the first invention occurs. Further, the rotation speed of the outer cylinder or the inner cylinder of the double cylinder type reactor for generating seed particles is adjusted, and the Taylor number is set within the range of 310 to 840.

According to the third invention, basically the same operation as that of the first or second invention occurs. Furthermore, a polymer raw material liquid containing a monomer is supplied from the lower end side of the double cylinder type reactor for generating seed particles, and a reaction liquid containing the seed particles generated in the double cylinder type reactor. Is taken out from the upper end side.

According to the fourth invention, basically the same operation as that of the first to third inventions occurs. Furthermore, the reaction temperature of the emulsion polymerization reaction is preferably controlled by adjusting the type, temperature or flow rate of the heat medium supplied to the jacket.

According to the fifth invention, in the continuous reactor,
With a sufficient number of seed particles having a high polymerization rate, the emulsion polymerization reaction using the seed particles as a core is performed to obtain a final polymer.

According to the sixth invention, basically the same action as that of the fifth invention occurs. Further, in the double cylindrical reactor, an emulsion polymerization reaction with seed particles as nuclei is performed in a state where Taylor vortices are generated, and a final polymer is obtained.

[0061]

EXAMPLES Hereinafter, with reference to FIGS. 3 to 10, a general structure of a double-cylindrical reactor which can be used as a continuous reactor for producing seed particles or for a second stage reaction. However, it goes without saying that the double cylindrical reactor used in the present invention is not limited to the one shown in FIGS. 3 to 10.

FIG. 4 shows an example of a double cylinder type reactor. This double-cylindrical reactor comprises a reaction container body 1 (outer cylinder 1), an inner cylinder 2, a motor 3 as a rotating means, a raw material liquid supply means 4 and a reaction liquid take-out means 5. The reaction container body 1 has a cylindrical inner surface, and its virtual central axis 6
Is installed so that it faces the vertical direction. Inner cylinder 2
Comprises a stainless cylindrical body having an outer surface forming a double cylindrical body coaxial with the inner surface of the main body 1, the lower end surface (bottom surface) and the upper end surface (upper surface) of the cylindrical body being respectively , The bottom plate 2a and the upper plate 2b made of the same material are closed by welding. That is, the inner cylinder 2 has a columnar appearance. The bottom plate 2a and the upper plate 2b of the inner cylinder 2 are fixed by welding to a rotary shaft 15 that is rotationally driven by a motor 3. That is, the inner cylinder 2 is rotatable around the central axis 6 by the motor 3. The bottom surface of the reaction container body 1 is formed in a circular shape so as to face the bottom plate 2a of the inner cylinder 2. A bottom plate 1a is attached to the cylindrical bottom surface of the main body 1, and a supply port 1c for supplying the polymer raw material liquid 9 is provided in the bottom plate 1a so as to open toward the inner cylindrical bottom plate 2a. The raw material liquid supply means 4 comprises a tank 7 for preparing a polymer raw material liquid as an emulsion, and a pipe line 8 extending from the bottom surface of the tank 7 to the supply port 1c. In conduit 8,
A valve 18 for adjusting the flow rate is provided as needed. The tank 7 is installed so that its bottom surface is higher than the upper plate 1b of the main body 1. A monomer or the like is appropriately supplied to the tank 7 from a dropping funnel 13 and the agitator 2 for agitating the raw material liquid 9 is provided.
1 is provided. The outlet 1d is provided in the upper plate 1b that closes the cylindrical upper surface of the main body 1. The reaction liquid take-out means 5 is composed of a pipe line 11 extending from the take-out port 1d to the reaction liquid reservoir tank 30, a cooler 12 and a rotary pump 13 provided in the middle of the pipe line 11. A heating / cooling jacket 14 is attached to the outside of the main body 1. Warm water 16 is added to the heating / cooling jacket 14.
The polymerization temperature in the main body 1 is controlled by passing through.

The polymer raw material liquid 9 prepared as an emulsion in the tank 7 enters the main body 1 from the supply port 1c through the pipe line 8 by the action of gravity. At this time, the polymer raw material liquid 9
Does not directly enter the annular space between the two cylinders, but once hits the bottom plate 2a of the inner cylinder so as to spread laterally and moves into the annular space. Thereby, the polymer raw material liquid 9 can be continuously supplied without disturbing the Taylor vortex generated in the annular space between both cylinders. Emulsion polymerization is carried out by rotating the inner cylinder 2 by the motor 3 to generate a Taylor vortex in the polymer raw material liquid 9 in the annular space between both cylinders (Fig. 3
reference). At this time, heating and / or cooling is performed as needed. During this period, the polymer raw material liquid 9 is continuously supplied. This causes the Taylor vortex to gradually move upward, and a new Taylor vortex is generated on the lower side. If the thermometer 17 is installed in the main body 1, it is easy to control the temperature. The polymer raw material liquid 9 that has moved upward is a reaction liquid in which polymer particles have become emulsified due to the progress of polymerization, and this is taken out by the rotary pump 13. If necessary, cooling is performed by the cooler 12 in the middle of the pipeline 11. The removed reaction solution is
It is stored in the reaction solution storage tank 30. Polymer particles are obtained by filtering this reaction solution.

FIG. 5 shows another example of the double cylindrical reactor. In this apparatus, the supply of the raw material liquid 9 is performed from the upper side of the double cylindrical reactor, that is, the upper plate 10b of the reaction container body 10.
Is carried out from the supply port 10c provided at the bottom of the double cylindrical reactor by gravity, that is, the take-out port 1 provided at the bottom plate 10a of the reaction vessel body 10.
It is similar to the device shown in FIG. 4 except that it is performed at 0d. In the case of the apparatus shown in FIG. 5, a pre-heater 20 may be installed so that heating can be performed before the raw material liquid is charged into the reaction apparatus main body 10. In the apparatus of FIG. 5, both supply and withdrawal of the polymer raw material liquid 9 are performed by gravity. The flow rate can be adjusted by, for example, the valve 19 provided in the pipeline on the downstream side of the outlet 10d.

6 to 10 show examples of specific shapes or dimensions of each member of the double cylindrical reactor. However, the shape or size of the double-cylindrical reactor used to actually generate the seed particles or the double-cylindrical reactor used as the continuous reaction device for the second stage reaction depends on the kind of raw material, the treatment Needless to say, it should be preferably set according to the amount, the polymerization reaction conditions and the like. 3 to 10, the same members are designated by the same reference numerals. Also, the unit of the numerical value showing the dimension in the figure is
mm.

The configuration or dimensions of each part of the apparatus shown in FIGS. 6 to 10 are set as follows, for example. Reaction vessel body 1: glass (heat-resistant glass) tube having a thickness of 2.4 mm, an inner diameter of 95.2 mm, and a length of 405 mm, a thickness of 5 mm, and a diameter of 1
Top plate made of 20mm glass plate, thickness 5mm, diameter 95.
A bottom plate made of a 2 mm glass plate that is integrated by welding.

Supply port: A through hole having a diameter of 15 mm provided 20 mm away from the center of the bottom plate toward the outside (provided on the upper plate in the apparatus shown in FIG. 5) (see FIGS. 8 and 9). . Outlet: A through hole having a diameter of 15 mm provided 20 mm away from the center of the top plate toward the outside (provided in the bottom plate in the device shown in FIG. 5) (see FIGS. 8 and 9). Bearing: A donut-shaped bearing plate made of tetrafluoroethylene resin with an outer diameter of 18 mm and a through hole 32 with an inner diameter of 8 mm in a through hole 33 with a radius of 18 mm from the center of the top plate and the bottom plate (thickness: 5 mm)
The one in which 31 is fitted (see FIGS. 8 to 10). Inner cylinder 2: thickness 3.8 mm, outer diameter 60.5 mm, length 400 m
An upper plate made of a stainless steel plate having a thickness of 2 mm and a diameter of 52.9 mm and a bottom plate made of a stainless steel plate having a thickness of 2 mm and a diameter of 52.9 mm are integrally welded to a stainless steel pipe of m.
Practical reaction tank volume (volume of space between double cylinder formed by main body 1 and inner cylinder 2): 1700 cm ³ . Rotating shaft 15: A stainless steel rod having a length of 645 mm and a diameter of 8 mm is welded to the upper plate and the bottom plate of the inner cylinder 2 and rotatably supported on the upper plate and the bottom plate of the main body 1. Heating jacket 14: A jacket made of glass (heat-resistant glass) having a thickness of 3 mm, an outer diameter of 150 mm, and a length of 345 mm is attached so as to cover 30 mm from both ends of the main body 1.

Hereinafter, a specific method for producing seed particles and a continuous multistage emulsion polymerization method using the seed particles will be described with reference to FIGS. 1 and 2. FIG. 1 is a system configuration diagram of a pre-reactor for producing seed particles for continuous multistage emulsion polymerization. As shown in FIG. 1, the pre-reactor 50 is provided with a first double cylindrical reactor 51. The first double cylindrical reactor 51 is provided with an outer cylinder 53 and an inner cylinder 54 that share an axis (center axis) extending in the vertical direction. Here, the outer cylinder 53 is of a fixed type, and a heating / cooling jacket 55 is attached to the outer peripheral portion of the outer cylinder 53. The reaction temperature can be controlled by adjusting the type, temperature, flow rate, etc. of the heat medium supplied to the heating / cooling jacket 55. On the other hand, the inner cylinder 54 has a structure rotatable about the above-mentioned axis and is rotationally driven by a motor 56. The motor 56 can adjust the rotation speed of the inner cylinder 54.

The raw material liquid supply port 57 and the reaction liquid take-out port 58 are arranged at the lower end side and the upper end side of the first double cylindrical reactor 51, respectively. Further, the raw materials in the first to third raw material tanks 59 to 61 are respectively fed to the first through the raw material liquid supply ports 57 by the first to third constant amount pumps 62 to 64, respectively.
It is adapted to be supplied to the double cylindrical reactor 51.
Here, each of the first to third metering pumps 62 to 64 can adjust the supply amount of the corresponding raw material.

Thus, in the pre-reactor 50,
The raw materials in the first to third raw material tanks 59 to 61 are supplied to the first double cylindrical reactor 51 at a predetermined supply rate, and Taylor vortices are generated in the first double cylindrical reactor 51. Emulsion polymerization is carried out in this state to produce seed particles for continuous multistage emulsion polymerization. Then, the reaction liquid containing the seed particles is taken out from the reaction liquid taking-out port 58.

FIG. 2 is a system configuration diagram of a continuous multi-stage emulsion polymerization apparatus in which, in addition to the pre-reaction apparatus 50 shown in FIG. 1, a continuous reaction apparatus 66 for performing a second-stage reaction is further provided. Since the structure of the pre-reactor 50 is the same as that in the case of FIG. 1, each member constituting the pre-reactor 50 is given the same number as that in FIG. 1 and its description is omitted. Figure 2
As shown in FIG. 5, the continuous reaction device 66 is provided with a second double cylindrical reactor 67. The second double cylindrical reactor 67 is provided with an outer cylinder 68 and an inner cylinder 69 that share an axis (center axis) extending in the vertical direction. Here, the outer cylinder 68 is of a fixed type, and a heating / cooling jacket 70 is attached to the outer peripheral portion of the outer cylinder 68. The reaction temperature can be controlled by adjusting the type, temperature, flow rate, etc. of the heat medium supplied to the heating / cooling jacket 70. On the other hand, the inner cylinder 69 has a structure rotatable about the above-mentioned axis and is rotationally driven by a motor 71. The motor 71 can adjust the rotation speed of the inner cylinder 69.

The raw material liquid supply port 72 and the reaction liquid take-out port 73 are arranged at the lower end side and the upper end side of the second double cylindrical reactor 67, respectively. Further, the raw materials in the fourth to fifth raw material tanks 74 to 75 are supplied to the continuous emulsifying machine 78 by the fourth to fifth constant amount pumps 76 to 77, respectively. Further, the reaction liquid containing the seed particles taken out from the first double cylindrical reactor 51 is also cooled by the cooling pipe 79 and then supplied to the continuous emulsifying machine 78. Then, in the continuous emulsifying machine 78, the raw material liquid (polymer raw material liquid) supplied from the fourth to fifth raw material tanks 74 to 75
And the reaction liquid containing the seed particles supplied from the first double cylindrical reactor 51 are mixed and emulsified, and this mixture is supplied to the second double cylindrical reactor 67 through the raw material liquid supply port 72. To be done.

Thus, in the continuous reaction device 66,
In a state where Taylor vortices are generated in the second double-cylindrical reactor 67, emulsion polymerization using seed particles as nuclei is performed, and a final polymer is produced. Then, the reaction liquid containing the final polymer is taken out from the reaction liquid taking-out port 73.

Example 1 A pre-reactor 50 shown in FIG.
In the first to third raw material tanks 59 to 61, styrene, an aqueous solution of potassium persulfate, and an aqueous solution of sodium dodecylbenzenesulfonate were respectively held, and then 100 g / l of styrene was supplied by the first to third constant amount pumps 62 to 64. −wate
r, potassium persulfate, and sodium dodecylbenzenesulfonate were continuously supplied to the first double cylindrical reactor 61 at the supply rates of 1.25 g / l-water and 6.25 g / l-water, respectively. Average residence time of reaction solution is 20 minutes, Taylor number is 310,
Polymerization was continuously carried out at a reaction temperature of 50 ° C., and the reaction liquid was continuously taken out from the first double cylindrical reactor 51. The resulting seed particle dispersion had a polymerization rate of 28.7% and the number of polymer particles produced was 2.6 × 10 ¹⁴ particles / cc, showing a high polymer particle generation efficiency (seed particle generation rate).

(Examples 2 to 4) Using the same composition and apparatus as in Example 1, the Taylor numbers were set to 480 and 62, respectively.
A seed emulsion (seed particles) was synthesized under the same operating conditions except that the number was changed to 0 and 840. The generation efficiency of these polymer particles is shown in Table 1. As is clear from Table 1, in each of these examples, a high seed particle generation rate was obtained.

[0076]

[Table 1]

(Example 5) To 1000 parts of the seed emulsion obtained in Example 2, 300 parts of styrene and 3 parts of potassium persulfate were added and stirred with a homodisper under a nitrogen stream to prepare a suspension. The suspension was supplied to a vertically long cylindrical stirring tank reactor as a reaction device to carry out emulsion polymerization. A propeller-type stirring blade was provided on the central shaft of the stirring tank reactor, and the suspension was supplied from the lower portion of the tank reactor and taken out from the upper portion. Emulsion polymerization has an average residence time of 60 minutes and stirring of 50 r.p.
m., reaction temperature 81-83 ° C. The fluctuation of the polymerization rate was stable in the range of 89% to 92%. During the continuous polymerization operation, neither aggregates nor coarse particles were generated, and no monomer separation was observed.

(Comparative Example 1) With the same composition as in Example 2,
A seed emulsion (seed particles) was synthesized by replacing the pre-reactor with a stirred tank reactor. Average retention time of reaction solution 20
Min, stirring 50 rpm, reaction temperature 50 ° C., the polymerization rate of the seed particle dispersion liquid obtained was 21.8%, the number of polymer particles produced was 1.4 × 10 ¹⁴ particles / cc, and the polymer particle generation efficiency was It was low. To 1000 parts of the obtained seed emulsion, 300 parts of styrene and 3 parts of potassium persulfate were added and stirred with a homodisper under a nitrogen stream to prepare a suspension.
This suspension was continuously supplied to a stirred tank reactor, the average residence time was 60 minutes, the stirring number was 50 rpm, and the reaction temperature was 81 to 83.
Emulsion polymerization was continuously carried out at 0 ° C., and the reaction liquid was continuously taken out from the main body. When the produced emulsion was sampled every 30 minutes and the polymerization rate was measured, the numerical value periodically fluctuated within the range of 78% to 89% and was unstable. Aggregates were observed to be generated during the continuous polymerization operation.

Example 6 Continuous emulsion polymerization was carried out by means of a double Taylor apparatus (continuous multistage emulsion polymerization apparatus) shown in FIG. In the pre-reactor 50, a seed emulsion (seed particles) was produced under the same conditions as in Example 2. After this suspension was cooled by a cooling pipe, it was emulsified with a styrene and an aqueous solution of an initiator in a continuous emulsifier 78 at 2000 rpm and continuously supplied to a Taylor apparatus. Styrene is 300g / l-wa
The ter and the initiator are supplied at 3 g / l-water, and the average residence time is 6
Emulsion polymerization was continuously performed for 0 minutes at a Taylor number of 480 and a reaction temperature of 81 to 83 ° C., and the reaction liquid was continuously taken out from the main body. When the produced emulsion was sampled every 30 minutes and the polymerization rate was measured, it was stable in the range of 91 to 92% with almost no numerical fluctuation. During the continuous polymerization operation, neither aggregates nor coarse particles were generated, and no monomer separation was observed.

Comparative Example 2 400 parts of styrene was added to a solution of 6.25 parts of sodium dodecylbenzenesulfonate and 4.25 parts of potassium persulfate in 1000 parts of deionized water, and the mixture was stirred with a homodisper under a nitrogen stream. To produce a suspension. This suspension was continuously fed directly to the Taylor apparatus without using a pre-reactor, with an average residence time of 60
Min, Taylor number 480, reaction temperature 81 to 83 ° C., emulsion polymerization was continuously carried out, and the reaction liquid was continuously taken out from the main body. When the emulsion was sampled every 30 minutes and the polymerization rate was measured, it was stable in the range of 85-88% with almost no numerical fluctuation, but monomer separation was observed and lumpy deposits were observed at the top of the reactor. It was

As described above, according to the method of the present invention, a sufficient number of seed particles having a high polymerization rate can be obtained, and further, during the reaction, separation of the monomer or adhesion of aggregates on the inner surface of the reactor can be caused. A polymer having a desired degree of polymerization with a narrow particle size distribution can be obtained without causing any problems.

[0082]

According to the first aspect of the present invention, in the double cylindrical reactor for producing seed particles, a state in which Taylor vortices are generated, that is, a state in which a perfect mixed flow and an extruded flow are generated. Then, emulsion polymerization of the polymer raw material liquid containing the monomer is performed, and the raw material liquid containing the seed particles is generated. Therefore, a large number of seed particles are generated at a high polymerization rate.

According to the second invention, basically the same effect as the first invention can be obtained. Furthermore, since the rotation speed of the outer cylinder or the inner cylinder of the double cylindrical reactor for generating seed particles is adjusted to set the Taylor number within the range of 310 to 840, the polymerization rate is further increased. A large number of seed particles are generated.

According to the third invention, basically the same effect as that of the first or second invention can be obtained. Furthermore, a polymer raw material liquid containing a monomer is supplied from the lower end side of the double cylinder type reactor for generating seed particles, and a reaction liquid containing the seed particles generated in the double cylinder type reactor. Is taken out from the upper end side, it is difficult for the monomer to float or separate, and the generation of aggregates is prevented or suppressed.

According to the fourth invention, basically the same effect as that of any one of the first to third inventions can be obtained. Furthermore, since the reaction temperature of the emulsion polymerization reaction is preferably controlled by adjusting the type, temperature or flow rate of the heat medium supplied to the jacket, the reaction temperature is stabilized,
The emulsion polymerization reaction is stabilized.

According to the fifth invention, in the continuous reactor,
Since a large number of seed particles having a high polymerization rate are used to perform the emulsion polymerization reaction with the seed particles as the core, a polymer having a narrow particle size distribution and a desired degree of polymerization can be obtained. In addition, the production efficiency is significantly improved as compared with the batch method.

According to the sixth invention, basically the same effect as that of the fifth invention can be obtained. Furthermore, since the emulsion polymerization, which is the second-stage reaction, is continuously carried out using the Taylor vortex, there is no problem such as separation of monomers during the reaction or adhesion of agglomerates on the inner surface of the reactor. A polymer having a narrow distribution and a desired degree of polymerization can be obtained.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a pre-reactor.

FIG. 2 is a system configuration diagram of a continuous multistage emulsion polymerization apparatus.

FIG. 3 is an explanatory diagram of a Taylor vortex.

FIG. 4 is a diagram showing an example of a double cylindrical reactor.

FIG. 5 is a diagram showing another example of a double cylindrical reactor.

FIG. 6 is an explanatory view showing a heating / cooling jacket and a reactor main body partially broken away.

FIG. 7 is a sectional view of an inner cylinder.

FIG. 8 is an enlarged side view of a main body and a bottom plate.

FIG. 9 is an enlarged plan view of a main body and a bottom plate.

FIG. 10 is an enlarged explanatory view of a bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reaction container main body 1c ... Supply port 1d ... Outlet port 2 ... Inner cylinder 2a ... Inner cylinder bottom plate 3 ... Rotating means motor 4 ... Raw material liquid supply means 5 ... Reaction liquid takeout means 6 ... Central shaft 10 ... Reaction Container main body 10c ... Supply port 10d ... Outlet port 14 ... Heating / cooling jacket 15 ... Rotating shaft 50 ... Pre-reactor 51 ... First double cylindrical reactor 53 ... Outer cylinder 54 ... Inner cylinder 55 ... Heating / cooling Jacket 57 ... Raw material liquid supply port 58 ... Reaction liquid outlet 66 ... Continuous reaction device 67 ... Second double cylindrical reactor 68 ... Outer cylinder 69 ... Inner cylinder

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[Procedure amendment]

[Submission date] November 22, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0078

[Correction method] Change

[Correction content]

(Comparative Example 1) With the same composition as in Example 2,
A seed emulsion (seed particles) was synthesized by replacing the pre-reactor with a stirred tank reactor. Average retention time of reaction solution 20
Min, stirring 500 rpm, reaction temperature 50 ° C., the polymerization rate of the seed particle dispersion obtained was 21.8%, the number of polymer particles produced was 1.4 × 10 ¹⁴ particles / cc, and the polymer particle generation efficiency was It was low. To 1000 parts of the obtained seed emulsion, 300 parts of styrene and 3 parts of potassium persulfate were added and stirred with a homodisper under a nitrogen stream to prepare a suspension. This suspension was continuously supplied to a stirred tank reactor, the average residence time was 60 minutes, the stirring number was 500 rpm, and the reaction temperature was 81.
Emulsion polymerization was continuously carried out at ˜83 ° C., and the reaction liquid was continuously taken out from the main body. The produced emulsion was sampled every 30 minutes and the polymerization rate was measured to be 78% to 89%.
The numerical value fluctuated periodically within the range of and was unstable.
Aggregates were observed to be generated during the continuous polymerization operation.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Keizo Ishii 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Paint Co., Ltd.

Claims (6)

[Claims] 1. A coaxial double-cylindrical reactor provided with an outer cylinder and an inner cylinder that share one axis extending in a direction intersecting with a horizontal plane is provided, and a part of a polymer raw material liquid containing a monomer is provided. , While continuously supplying to the annular space portion between the outer cylinder and the inner cylinder of the double cylindrical reactor from one end side in the axial direction, at least one of the cylinders is rotated around the axis line in the annular space portion. A Taylor vortex is generated in the polymer material liquid in the annular space, and an emulsion polymerization reaction is generated in the state where the Taylor vortex is generated to generate seed particles for continuous multistage emulsion polymerization. A method for producing seed particles for emulsion polymerization, characterized in that the reaction liquid containing the above is introduced to the outside from the other end side in the axial direction of the double cylindrical reactor to continuously obtain seed particles. 2. The method for producing seed particles for emulsion polymerization according to claim 1, wherein the outer cylinder or the inner cylinder is rotated so that the Taylor number becomes 310 to 840. 3. The polymer raw material liquid is supplied from the lower end side of the double cylindrical reactor, and the reaction liquid containing seed particles is guided to the outside from the upper end side of the double cylindrical reactor. The method for producing seed particles for emulsion polymerization according to claim 1 or 2. 4. A jacket is provided on the outer surface of the outer cylinder, and a heating medium is supplied to the jacket to control the temperature of the polymer raw material liquid in the annular space to cause an emulsion polymerization reaction. Claims 1 to 3 characterized by
1. The method for producing seed particles for emulsion polymerization according to any one of 1. 5. The seed particles produced by the method according to any one of claims 1 to 4 and a polymer raw material liquid containing a monomer are supplied to a continuous reaction device to form seed particles as a nucleus. The continuous multistage emulsion polymerization method is characterized in that the final polymer is obtained by carrying out an emulsion polymerization reaction. 6. A coaxial double cylindrical reactor provided with an outer cylinder and an inner cylinder sharing one axis extending in a direction intersecting a horizontal plane is used as a continuous reaction device, and seed particles and a polymer raw material liquid are used. Is continuously supplied to the annular space portion between the outer cylinder and the inner cylinder of the double-cylindrical reactor from one end side in the axial direction, while rotating at least one cylinder around the axial line to form the annular space. A Taylor vortex is generated in the part, and an emulsion polymerization reaction is caused in the seed particles and the polymer raw material liquid in the annular space part in a state where the Taylor vortex is generated to generate a final polymer. 6. The reaction solution containing the final polymer is introduced to the outside from the other end side in the axial direction of the double cylindrical reactor so as to continuously obtain the final polymer. The continuous multistage emulsion polymerization method described in.