JP5089957B2 - Aqueous dispersion manufacturing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing an aqueous dispersion which can stably produce an aqueous dispersion having a small average particle diameter and a small amount of an unemulsified material. <P>SOLUTION: The apparatus for producing an aqueous dispersion has a twin-screw extruder 10 in which two screws 12a are disposed in a barrel 11, a cooling means 20 provided on the forward end side of the barrel 11 of the twin-screw extruder 10, and a flow passage 30 which connects the forward end of the twin-screw extruder 10 with the cooling means 20, and part of the flow path 30 is constituted of a connecting pipe 32 and the diameter D (mm) of the screw 12a of the twin-screw extruder 10, the bore diameter d (mm) of the connecting pipe 32, and the length L (mm) of the flow path 30 meet the relationship of equation (1): 2&le;ä(D<SP>3</SP>&times;L)/d<SP>4</SP>}&le;300. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an aqueous dispersion production apparatus for continuously producing an aqueous dispersion of a thermoplastic resin.

An aqueous dispersion in which a thermoplastic resin is dispersed in an aqueous medium may be used as a raw material for adhesives, paints, resin modifiers, and the like.
As a method for producing an aqueous dispersion, for example, a method utilizing a phase inversion phenomenon using an extruder (hereinafter referred to as an extrusion phase inversion method) is known. In the method for producing an aqueous dispersion by the extrusion phase inversion method, the thermoplastic resin is phase-inverted in the presence of a small amount of water of up to 25% by mass to form an apparently solid “phase inversion body”. The phase inversion body is diluted with water or warm water to obtain an aqueous dispersion having an arbitrary solid content concentration (see, for example, Patent Document 1).
When the aqueous dispersion is continuously produced by the method, for example, a twin-screw extruder, cooling means provided on the tip side of the twin-screw extruder, barrel tip and cooling means of the twin-screw extruder And an aqueous dispersion manufacturing apparatus in which a part of the flow path is a connecting pipe. In order to produce an aqueous dispersion using this production apparatus, for example, a polyolefin, an acid-modified polyolefin and an emulsifier are melt-kneaded by a twin screw extruder, and water or an aqueous solution of a basic substance is added to the twin screw extruder. After feeding and mixing these, the phase inversion is sent to the cooling means through the flow path, cooled to a temperature lower than the boiling point of water, and further dispersed in water by addition of water to form an aqueous dispersion. Get the body. (For example, refer to Patent Document 2).
Japanese Patent Publication No. 7-8933 Japanese Examined Patent Publication No. 7-96647

Usually, the aqueous dispersion is required to have a small average particle size. However, when the production apparatuses described in Patent Documents 1 and 2 are used, an aqueous dispersion having a small average particle size may not be produced stably.
Furthermore, the aqueous dispersion is required to have a small amount of non-emulsified product. This is because when the amount of the non-emulsified material is large, not only the non-emulsified material but also a part of the aqueous dispersion adhering to the non-emulsified material is removed when the aqueous dispersion is filtered. This is because the yield decreases. Usually, the aqueous dispersion is diluted in a diluting tank. However, if the amount of unemulsified material is large, the apparent fluidity tends to decrease during dilution, or air entrainment tends to increase. This is because it takes a long time to complete the process and the productivity is lowered.
This invention is made | formed in view of the said situation, and it aims at providing the manufacturing apparatus of the aqueous dispersion which can manufacture stably the aqueous dispersion with a small average particle diameter and little unemulsified amount. .

The present inventors examined a method for stably producing an aqueous dispersion having a small average particle size and a small amount of non-emulsified material in the extrusion phase inversion method. As a result, when the screw diameter of the twin screw extruder, the hole diameter of the connecting pipe, and the length of the flow path from the twin screw extruder to the cooling means have a specific relationship, the average particle diameter is small and not yet It has been found that an aqueous dispersion with a small amount of emulsion can be obtained. And based on the knowledge, it further examined and invented the manufacturing apparatus of the following aqueous dispersion.
That is, the manufacturing apparatus of the aqueous dispersion of the present invention includes a twin screw extruder in which two screws are provided in a barrel, a cooling means provided on the tip side of the twin screw extruder, and a twin screw extruder. comprising a flow path that connects the barrel tip and the cooling means, Ri part of the channel Do from the connecting pipe, the manufacturing apparatus of an aqueous dispersion that is used in preparing the aqueous dispersion of the following thermoplastic resin Because
The screw diameter D (mm) of the twin screw extruder, the hole diameter d (mm) of the connecting pipe, and the length L (mm) of the flow path satisfy the relationship of the following formula (1).
Formula (1) 2 ≦ {(D ³ · L) / d ⁴ } ≦ 300
Thermoplastic resin: Polymer obtained by polymerizing at least α-olefin, random copolymer or block copolymer of styrene and butadiene or hydrogenated product of these copolymers, random copolymer or block copolymer of styrene and isoprene Hydrogenated product of copolymers or copolymers thereof

  According to the aqueous dispersion production apparatus of the present invention, an aqueous dispersion having a small average particle size and a small amount of non-emulsified material can be produced stably.

An embodiment of an apparatus for producing an aqueous dispersion of the present invention (hereinafter abbreviated as a production apparatus) will be described.
FIG. 1 shows a manufacturing apparatus according to this embodiment. The manufacturing apparatus 1 includes a twin screw extruder 10 in which two screws 12a and 12b are disposed in a heatable barrel 11, a cooling means 20 provided on the tip 10a side of the twin screw extruder 10, and two A flow path 30 that connects the tip of the barrel 11 of the axial extruder 10 and the cooling means 20 in an airtight state, a first supply means 40 that supplies thermoplastic resin, acid-modified polyolefin, and an emulsifier to the end 11a side of the barrel 11; And a second supply means 50 for supplying an aqueous medium to an intermediate portion of the barrel 11.

The twin-screw extruder 10 constituting the production apparatus 1 is used to invert the phases after adding an aqueous medium to a thermoplastic resin. The phase inversion here means that the state is changed from a state in which the aqueous medium is dispersed in the thermoplastic resin to a state in which the thermoplastic resin is dispersed in the aqueous medium.
The rotation directions of the two screws 12a and 12b of the twin-screw extruder 10 may be the same direction or different directions.

  The cooling means 20 in the present embodiment is a jacketed static mixer and is used to cool the product obtained by the twin screw extruder 10.

The flow path 30 is for transferring the phase inversion body obtained by the twin-screw extruder 10 to the cooling means 20.
As shown in FIG. 2, the flow path 30 in the present embodiment is more specifically, the hole 31 on the tip end side of the barrel 11 of the twin-screw extruder 10 and the hole of the connecting tube 32 connected to the hole 31. It consists of a portion 32 a and a hole 33 formed on the end side of the cooling means 20. That is, the length L of the flow path 30 is the length from the screw tip 12 c of the twin-screw extruder 10 to the cooling means 20.

Specifically, the hole 31 is a hole of an adapter attached to the tip of the barrel 11.
The connecting pipe 32 is a metal pipe such as stainless steel. The connecting pipe 32 is preferably provided with an external heater, a temperature sensor, a temperature controller, and, if necessary, a heat insulating material, a cooling mechanism of air cooling or water cooling, so that the temperature of the outer wall of the pipe can be controlled. By controlling the temperature of the outer wall of the tube, it is possible to stably produce an aqueous dispersion having a smaller average particle diameter and a smaller amount of non-emulsified material.

As the 1st supply means 40, the fixed_quantity | feed_rate feeder generally used with an extruder can be used, for example. If a quantitative feeder is used, an aqueous dispersion having a desired average particle diameter can be easily produced, and the amount of non-emulsified material in the aqueous dispersion can be reduced.
As the second supply means 50, for example, a container 51 filled with an aqueous medium, a pump 52 for feeding the aqueous medium in the container 51 to the twin-screw extruder 10, and a supply in which the pump 52 and the twin-screw extruder 10 are connected to each other. For example, a liquid supply means including the pipe 53 may be used. As the pump 52, for example, a diaphragm pump, a plunger pump, or the like can be used.
The aqueous dispersion discharged from the cooling means 20 can be diluted to an arbitrary concentration in a tank having a stirrer, and warm water is preferably used for dilution.

In the manufacturing apparatus 1, the diameter D of the screws 12 a and 12 b of the twin-screw extruder 10, the hole diameter d of the connection pipe 32, and the length L of the flow path 30 satisfy the relationship of the following formula (1).
Formula (1) 2 ≦ {(D ³ · L) / d ⁴ } ≦ 300
If the hole diameter of the connecting pipe 32 is small or the length of the flow path 30 is long and {(D ³ · L) / d ⁴ } exceeds 300, the resin pressure at the tip of the twin screw extruder 10 increases. As a result, the phase inversion body and the leakage of water vapor are concerned. Once the water vapor begins to leak, an aqueous dispersion cannot be obtained, and production must be stopped, making continuous operation impossible.
On the other hand, when the pore diameter of the connecting pipe 32 is large and {(D ³ · L) / d ⁴ } is less than 2, an aqueous dispersion having a small average particle diameter and a small amount of non-emulsified material cannot be obtained. .
Moreover, it is more preferable that the diameter D of the screws 12a and 12b of the twin screw extruder 10, the hole diameter d of the connecting pipe 32, and the length L of the flow path 30 satisfy the relationship of the following formula (2).
Formula (2) 10 ≦ {(D ³ · L) / d ⁴ } ≦ 300
When {(D ³ · L) / d ⁴ } is 10 or more, the average particle diameter can be made smaller and the amount of non-emulsified product can be made smaller.
Since the flow path 30 includes the holes 31 and 33, in the above formula (1) or (2), not only the length of the hole 32 a of the connection pipe 32 but also the length of the holes 31 and 33 is not obtained. The impact is also taken into account.

In addition, when the flow path 30 is bent, the length of the flow path 30 is measured at the center position. Further, when the hole diameter of the flow path 30 is not constant, the flow path 30 is divided into n portions that can be approximated to a constant tube diameter in the length direction, and {(D _n ³ · L _n ) / d _n ⁴ } is obtained, and {(D _n ³ · L _n ) / d _n ⁴ } for all the minute portions is summed. Then, and their sum ^{{(D 3 · L) /} d 4}.

The manufacturing method (henceforth a manufacturing method) of the aqueous dispersion using the manufacturing apparatus 1 mentioned above is demonstrated.
In the manufacturing method of the present embodiment, first, the thermoplastic resin, the acid-modified polyolefin, and the emulsifier are put into the end of the barrel 11 while rotating the two screws 12 a and 12 b of the twin-screw extruder 10 heated in the barrel 11. These are continuously fed to the 11a side and melt kneaded.
The supply amount of the thermoplastic resin is preferably selected as appropriate according to the scale of the twin-screw extruder 10 (specifically, the diameter of the screw).
The supply amount of the emulsifier is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin. If the supply amount of the emulsifier is 1 part by mass or more with respect to 100 parts by mass of the thermoplastic resin, the thermoplastic resin can be easily dispersed in the aqueous medium, and if it is 20 parts by mass or less, the aqueous dispersion Can prevent foaming.

  The temperature inside the barrel 11 of the twin screw extruder 10 is preferably adjusted to 100 to 250 ° C. If the temperature in the barrel 11 of the twin screw extruder 10 is 100 ° C. or more and 250 ° C. or less, the aqueous dispersion can be easily produced.

Next, the aqueous medium is continuously supplied to the middle part of the barrel 11 by the second supply means 50, and melt-kneaded and phase-inverted to prepare a phase inversion body.
It is preferable that the supply amount of an aqueous medium is 1-35 mass parts with respect to 100 mass parts of thermoplastic resins. If the supply amount of the aqueous medium is 1 part by mass or more with respect to 100 parts by mass of the thermoplastic resin, the aqueous dispersion can be easily produced, and if it is 35 parts by mass or less, the thermoplastic resin can be easily made into fine particles. .
It is preferable that the aqueous medium is supplied constantly because an aqueous dispersion having a desired average particle diameter can be easily produced and the amount of the non-emulsified material can be reduced. For that purpose, it is preferable to use a highly accurate pump 52 of the second supply means 50.

  Thereafter, the phase inversion body obtained by the twin screw extruder 10 is transferred to the cooling means 20 through the flow path 30, cooled to below the boiling point of the aqueous medium by the cooling means 20, and dispersed in water from the tip of the cooling means 20. The body is discharged. The obtained aqueous dispersion is received in a dilution tank, and the inside of the dilution tank is stirred with a stirrer to obtain an aqueous dispersion diluted to a predetermined concentration.

Examples of the thermoplastic resin used in the production method include ethylene, propylene, 1-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 1-heptene. , 1-hexene, 1-octene, 1-decene, α-olefins such as 1-dedecene, homopolymers, copolymers of these monomers, these monomers and nonconjugated dienes, conjugated dienes, unsaturated carboxylic acids, unsaturated carboxylic acids Examples thereof include a copolymer obtained by copolymerization with an anhydride or the like.
Specifically, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-conjugated diene copolymer, ethylene-butene copolymer, ethylene-butene-propylene copolymer, and ethylene-octene copolymer are preferable. . In addition, modified polymers obtained by introducing acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and maleic anhydride into these homopolymers or copolymers are also preferred.

Examples of the thermoplastic resin include random copolymers and block copolymers of styrene and butadiene or isoprene, hydrogenated products thereof, various vinyl ester copolymers such as vinyl acetate, and hydrolysates thereof. It can also be used. Of the various vinyl ester copolymers and hydrolysates thereof, ethylene-vinyl acetate and partially saponified or highly saponified products thereof are preferably used.
A thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  For example, additives such as an antioxidant, a stabilizer, a lubricant, a plasticizer, and an inorganic filler may be added to the thermoplastic resin in advance.

  Examples of the acid-modified polyolefin include a modified product in which a carboxylic acid or a carboxylic acid anhydride is bonded to a homopolymer or copolymer of an α-olefin. Examples thereof include maleic anhydride-modified polyethylene having an acid value of 10 to 200 mg / g, maleic anhydride-modified ethylene-propylene copolymer, maleic anhydride-modified polypropylene, and ethylene- (meth) acrylic acid copolymer. One type of acid-modified polyolefin may be used alone, or two or more types may be used in combination.

Examples of the emulsifier used in this production method include various anionic surfactants and nonionic surfactants.
Examples of the anionic surfactant include primary higher fatty acid salts, secondary higher fatty acid salts, primary higher alcohol sulfates, secondary higher alcohol sulfates, primary higher alkyl sulfonates, Secondary higher alkyl sulfonate, higher alkyl disulfonate, sulfonated higher fatty acid salt, higher fatty acid sulfate ester salt, higher fatty acid ester sulfonate salt, higher alcohol ether sulfate ester, higher alcohol ether sulfonate salt, Examples include alkylolated sulfates of higher fatty acid amides, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, and alkylbenzoylimidazole sulfonates. An anionic surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.
The higher fatty acid constituting the emulsifier includes saturated fatty acids such as capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, and arachidic acid, Examples thereof include unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, and arachidonic acid, or mixtures thereof.
Examples of elements for forming salts with higher fatty acids include alkali metals such as sodium and potassium.

As the nonionic surfactant, those having an HLB (hydrophilic lipophilic balance) value of 10 or more are used. For example, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene fatty acid amide Examples include ether, polyhydric alcohol fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid ester, fatty acid sucrose ester, alkylolamide, polyoxyalkylene block copolymer and the like. A nonionic surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.
When two or more kinds of nonionic surfactants are used in combination, the HLB of the mixture is preferably 10 or more.

  The emulsifier may be a powdery or granular solid, or may be a liquid.

As an aqueous medium used in this production method, for example, water or an aqueous solution of a basic substance is used.
Basic substances include alkali metals, alkaline earth metals, ammonia, amines and alkali metal oxides, hydroxides, weak acid salts, hydrides, and alkaline earth metal oxides, hydroxides, weak acid salts, An aqueous solution of hydride or the like can be mentioned. A basic substance may be used individually by 1 type, and may use 2 or more types together.
Among aqueous media, an aqueous solution of a basic substance is preferable because an aqueous dispersion can be easily produced, and a 5 to 30% by mass aqueous solution of potassium hydroxide is more preferable.

In the manufacturing apparatus 1 described above, the expression {(D ³ · L) / d ⁴ } is within a specific range as described above. As a result of investigations by the present inventors, it has been found that by producing an aqueous dispersion with such a production apparatus 1, an aqueous dispersion with a small amount of non-emulsified material and a small average particle diameter can be produced stably.

The aqueous dispersion obtained by the production apparatus 1 exhibits adhesion, corrosion resistance, gas barrier properties, chipping resistance, heel mark resistance, and the like according to the type of thermoplastic resin. And depending on the effect, it can be used as a moisture-proofing agent, water repellent, film forming agent, coating agent on the product surface, or combined with other materials as a fiber treatment agent, heat sealant, binder, primer, etc. Or
The aqueous dispersion can be used as a raw material for a resin modifier made of a graft copolymer.

  Note that the present invention is not limited to the above-described embodiments. For example, as a cooling means, besides a jacketed static mixer, a single-screw or multi-screw extruder can be used.

[Example 1]
As shown in FIG. 1, the manufacturing apparatus used in this example is a twin-screw extruder 10 (manufactured by Ikekai Tekko Co., Ltd., “PCM-54 type”) in which two screws are arranged in a heatable barrel 11. The diameter of the screw; 54 mm), and between the static mixer with jacket which is the cooling means 20 provided on the tip side of the twin screw extruder 10 and the tip of the barrel 11 of the twin screw extruder 10 and the static mixer with jacket are airtight. A flow path 30 connected in a state, a first supply means 40 for supplying a thermoplastic resin, an acid-modified polyolefin and an emulsifier to the end 11a side of the barrel 11, and a second supply for supplying an aqueous medium to an intermediate portion of the barrel 11 And supply means 50.
The diameter of the screw of the twin screw extruder in this manufacturing apparatus is 54 mm, the connecting pipe 32 constituting a part of the flow path 30 has a hole diameter of 46 mm and a length of 600 mm, and the flow path 30 has a length L. Is 700 mm. Therefore, {(D ³ · L) / d ⁴ } is 25.

  In this example, first, while rotating the two screws 12a and 12b of the twin screw extruder 10 in the same direction, EPDM which is a thermoplastic resin (MFR at 190 ° C. is 7 g / 10 min) is an average supply rate of 45 kg. Per hour, acid-modified polyethylene, which is an acid-modified polyolefin (mass average molecular weight; 2700, acid value; 30 mg / g), at an average supply rate of 7 kg / hour and potassium oleate as an emulsifier, at an average supply rate of 1.4 kg / hour Were continuously supplied to the end 11a side of the barrel 11 to melt and knead them. At that time, the temperature in the barrel of the twin screw extruder 10 was set to 200 ° C.

In addition, the 14 mass% potassium hydroxide aqueous solution was supplied to the middle portion of the barrel 11 by the second supply means 50 at an average supply rate of 1.8 kg / hour. Then, in the presence of an emulsifier, the thermoplastic resin and the aqueous medium were mixed and phase-inverted.
Then, the phase inversion body obtained with the twin-screw extruder 10 was transferred to the static mixer with a jacket via the connecting pipe 32 heated to 190 degreeC, and it cooled to 95 degreeC and took out.
Next, the discharged material from the tip of the jacketed static mixer was received in a dilution tank charged with warm water, stirred and diluted with a stirrer to obtain an emulsion-like aqueous dispersion. The average particle size of this aqueous dispersion and the mass ratio of the non-emulsified product were measured. The results are shown in Table 1.

<Average particle size>
The average particle size in the aqueous dispersion was measured by Microtrac UPA (manufactured by Mountaintech Co. Ltd).
<Mass ratio of non-emulsified>
The aqueous dispersion was filtered through a 100 mesh stainless steel wire mesh, and the residue on the mesh was washed with water and dried, and then the mass of the filtered solid residue was measured. And the mass ratio of the non-emulsified thing in an aqueous dispersion was calculated | required by following formula (3).
Formula (3) Mass ratio of non-emulsified material (mass%) = [mass of filtered solid content (g) / mass of total solid content (g)] × 100 (mass%)
When the mass ratio of the non-emulsified material is about 50% by mass or less, it is possible to suppress a decrease in yield and productivity of the aqueous dispersion.

[Example 2]
A PCM-30 type (screw diameter: 30 mm) manufactured by Ikekai Tekko Co., Ltd. is used as the twin screw extruder 10, and an FS-40 type manufactured by Ikegai Iron Works Co., Ltd. is used as the cooling means 20, and the connecting pipe 32 has a hole diameter d Was changed to a length of 15 mm and a length of 400 mm, and the length L of the flow path 30 was changed to 480 mm. In this case, {(D ³ · L) / d ⁴ } is 256.
A thermoplastic resin, LLDPE (MFR; 3.8 g / 10 min, melting point: 98 ° C., Vicat softening point; 83 ° C.) was continuously supplied at 7.7 kg / hour, and the acid-modified polyethylene was supplied at a rate of 0. At 77 kg / hour, the supply rate of potassium oleate was changed to 0.23 kg / hour, and the 14 mass% potassium hydroxide aqueous solution was changed to 0.30 kg / hour, respectively. Except for these, an aqueous dispersion was obtained in the same manner as in Example 1. The average particle diameter of the obtained aqueous dispersion and the mass ratio of the non-emulsified were measured in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
The connecting pipe 32 was changed to one having a hole diameter d of 30 mm and a length of 400 mm, and the length L of the flow path 30 was changed to 480 mm. In this case, {(D ³ · L) / d ⁴ } is 16. Except these, it carried out similarly to Example 2, and obtained the aqueous dispersion. The average particle diameter of the obtained aqueous dispersion and the mass ratio of the non-emulsified were measured in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
The connecting pipe 32 was changed to one having a hole diameter d of 40 mm and a length of 400 mm, and the length L of the flow path 30 was changed to 480 mm. In this case, {(D ³ · L) / d ⁴ } is 5.1. Except these, it carried out similarly to Example 2, and obtained the aqueous dispersion. The average particle diameter of the obtained aqueous dispersion and the mass ratio of the non-emulsified were measured in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
The connecting pipe 32 was changed to one having a hole diameter d of 24 mm and a length of 600 mm, and the length L of the flow path 30 was changed to 700 mm. In this case, {(D ³ · L) / d ⁴ } is 332. Except for these, the production of an aqueous dispersion was attempted in the same manner as in Example 1. However, the pressure at the tip of the twin-screw extruder increased, the thermoplastic resin and water vapor leaked, and the operation could not be continued, and an aqueous dispersion could not be obtained.

[Comparative Example 2]
The connecting pipe 32 was changed to one having a hole diameter of 100 mm and a length of 600 mm, and the length L of the flow path 30 was changed to 700 mm. In this case, {(D ³ · L) / d ⁴ } is 1.1. Except for these, an aqueous dispersion was produced in the same manner as in Example 1. The average particle diameter of the obtained aqueous dispersion and the mass ratio of the non-emulsified were measured in the same manner as in Example 1. The results are shown in Table 1.

According to the production apparatus of Examples 1 to 4 in which {(D ³ · L) / d ⁴ } is in the range of 2 to 300, an aqueous dispersion having a small average particle size and a small amount of non-emulsified material is stable. Could be manufactured.
On the other hand, in the production apparatus of Comparative Example 1 in which {(D ³ · L) / d ⁴ } exceeded 300, it was difficult to produce an aqueous dispersion itself.
In the production apparatus of Comparative Example 2 in which {(D ³ · L) / d ⁴ } is less than 2, the average particle diameter of the obtained aqueous dispersion exceeded 1 μm, and a large amount of non-emulsified product was by-produced. Therefore, it cannot be said to be an excellent method for producing an aqueous dispersion.

It is a schematic diagram which shows one embodiment of the manufacturing apparatus of the aqueous dispersion of this invention. It is the figure which expanded the flow path which comprises the manufacturing apparatus of the aqueous dispersion of FIG. 1, and its vicinity.

Explanation of symbols

1 Production equipment (Aqueous dispersion production equipment)
DESCRIPTION OF SYMBOLS 10 Twin screw extruder 11 Barrel 12a, 12b Screw 20 Cooling means 30 Channel 31, 32a, 33 Hole 32 Connection pipe 40 First supply means 50 Second supply means 51 Container 52 Pump 53 Supply pipe

Claims (1)

A twin-screw extruder in which two screws are arranged in the barrel, a cooling means provided on the tip side of the twin-screw extruder, and a flow path connecting the barrel tip and the cooling means of the twin-screw extruder provided by, Ri part of the channel Do from the connecting pipe, a manufacturing apparatus of an aqueous dispersion that is used in preparing the aqueous dispersion of the following thermoplastic resins,
Aqueous water characterized in that the diameter D (mm) of the screw of the twin screw extruder, the hole diameter d (mm) of the connecting pipe, and the length L (mm) of the flow path satisfy the relationship of the following formula (1). Dispersion manufacturing equipment.
Formula (1) 2 ≦ {(D ³ · L) / d ⁴ } ≦ 300
Thermoplastic resin: Polymer obtained by polymerizing at least α-olefin, random copolymer or block copolymer of styrene and butadiene or hydrogenated product of these copolymers, random copolymer or block copolymer of styrene and isoprene Hydrogenated product of copolymers or copolymers thereof

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