JPH051122A - Continuous bulk polymerization of impact-resistant styrenic resin - Google Patents

Abstract

PURPOSE:To obtain the resin having excellent impact strength and luster and small luster gradient by using a specific polymerizing line, preliminarily polymerizing a specific polybutadiene, etc., and a styrenic monomer by a dynamic blending reactor in the line and then performing main polymerization. CONSTITUTION:A polybutadiene and/or styrene-butadiene copolymer rubber which is fed from a raw material feed line I and has 10-50 CPS viscosity in 5wt.% styrene solution at 25 deg.C and a styrenic monomer are preliminarily polymerized firstly in a dynamic blending reactor 2, the polymerization ratio reaches 10-28wt.%, then initial polymerization (35-55wt.% polymerization conversion ratio) is carried out by circulating the prepolymer from an initial polymerization line II composed of one or more ring-shaped reactors to which plural mixing elements having no mobile parts at all are internally fixed through a refluxing line IV to the initial polymerization line II again and the initial polymerization liquid flow which was not refluxed is mainly polymerized by a main polymerization line III of the same structure as the initial polymerization line II to give the objective resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous bulk polymerization method of impact-resistant styrenic resin, and more particularly to a method for producing impact-resistant styrene-based resin having excellent impact strength and gloss and having a small gloss gradient. .

[0002]

2. Description of the Related Art In producing impact-resistant styrenic resin by graft-polymerizing a styrenic monomer in the presence of a rubbery polymer, the rubbery polymer is made into fine particles and uniformly dispersed. It is particularly important to stabilize the rubber particles once formed in order to determine the quality of the obtained resin. In particular, the particle size and distribution of the grafted rubbery polymer dispersed in the final resin, the graft ratio of the styrene-based monomer, and the like greatly affect the gloss and impact strength of the product.

Conventionally, batch-type bulk-suspension polymerization methods and continuous bulk-polymerization methods have been generally employed as industrial methods for producing high-impact polystyrene, but the continuous methods are preferred because of their productivity and economy. Due to its superiority, continuous bulk polymerization is becoming the mainstream.

Usually, in the continuous bulk polymerization method, the method disclosed in
As proposed in 60-28407, a production method is generally used in which several stirring tank reactors are connected in series to continuously supply a raw material solution to promote polymerization.

However, in this continuous bulk polymerization method,
The drawbacks associated with dynamic mixing with a stirrer have been pointed out. That is, as the viscosity of the polymerization liquid in the reactor increases as the polymerization progresses, it becomes necessary to increase the power required to continue stirring and the strength of the stirring blade. Further, if excessive stirring and mixing are carried out in an attempt to make the rubbery polymer into fine particles, an excessive shearing force is applied to the once dispersed rubbery polymer, so that the excess of the dispersed particles of the rubbery polymer is added. Breakage occurs, the particle size distribution is widened, and as a result, the impact strength and gloss of the product are reduced.

Therefore, in order to improve such drawbacks, several proposals have been made in this polymerization method, such as improvement of stirring blades, adoption of a tubular reactor having a stirrer, and adoption of a circulation line. However, the one which can be satisfied enough has not appeared yet.

For example, in Japanese Patent Publication No. 55-8526, a tower type reactor having a so-called circulation polymerization line and a stirrer is used, in which a polymerization liquid which has passed through a polymerization line consisting of a ring reactor is advanced to the polymerization line again. The dispersion and fine particle formation of the rubbery polymer are controlled by stirring and circulating the polymerization liquid. However, this method tends to increase the average particle size when the amount of circulation is increased in an attempt to uniformly disperse the rubbery polymer, and the average particle size of the rubbery polymer in the product is small and its distribution is narrow. When trying to obtain a resin, it is necessary to rely on the conventional means of reducing the circulation amount and increasing the number of rotations of the stirrer, which eventually results in deterioration of product strength and gloss.

[0008] On the other hand, in the market, as the replacement of expensive ABS resin with impact-resistant polystyrene is progressing in order to reduce the cost of plastics, the demand for a resin having a good balance of physical properties of gloss and strength is increasing. There is. In particular, regarding the gloss of the molded product, a resin having a gloss comparable to that of the ABS resin and having a small gloss gradient, that is, a resin having a small decrease in gloss from the gate portion to the end portion of the molded product is required.

Therefore, in order to obtain such a resin,
The average particle size of the rubbery polymer particles in the product must be controlled to 1.0 micron or less, but with the conventional manufacturing technology, when the average particle size of the rubbery polymer is 1.0 micron or less, the impact strength is significantly reduced. , I am not getting satisfactory results.

In Japanese Patent Laid-Open No. 63-30515, in order to solve the disadvantages associated with the continuous bulk polymerization method using the above-mentioned stirring type reactor, a plurality of mixing elements having no movable parts are fixed inside. A continuous process for making high impact polystyrene using a tubular reactor has been proposed.

In this method, a styrene monomer is continuously added from a raw material supply line in the presence of polybutadiene and / or styrene-butadiene copolymer rubber, and a plurality of mixing elements having no moving parts are fixed inside. An initial polymerization line consisting of one or more annular reactors, a main polymerization line consisting of one or more annular reactors, which continues from the initial polymerization line and in which a plurality of mixing elements without any moving parts are fixed. A polymerization line constituted by a reflux line branching between the polymerization line and the main polymerization line and returning to the initial polymerization line is used, and most of the initial polymerization liquid flow exiting the initial polymerization line is refluxed through the reflux line. On the other hand, the dispersion stability of the rubbery polymer is achieved by continuous bulk polymerization in which the unpolymerized initial polymerization liquid stream is polymerized in the main polymerization line. It has achieved. In this method, the quality control is performed by relating the polymerization conversion rate of the styrene-based monomer in the initial polymerization to the rubbery polymer concentration of the polymerization solution.

[0012]

However, according to the method disclosed in Japanese Patent Laid-Open No. 63-30515, in order to obtain an impact-resistant styrenic resin having an average particle size of the rubbery polymer of 1.0 micron or less and excellent gloss. In the initial polymerization line, the polymerization conversion rate is kept to 20% by weight or less and the reflux ratio R (at the outlet of the initial polymerization line, the flow rate F1 of the polymerization liquid refluxing without flowing to the next main polymerization line and The ratio F1 / F2 of the flow rate F2 of the polymerization liquid flowing out to the main polymerization line must be increased to at least 8 or more. In that case, although a rubbery polymer having an average particle size of about 0.9 to 1.0 micron can be obtained, unfortunately, the gloss near the gate portion of the molded product is excellent, but the gloss away from the gate portion is inferior. It is not possible to obtain a resin with a small gloss gradient. Further, a polymerization liquid having a polymerization conversion rate of 20% by weight or less in a circulation polymerization line,
That is, when the polymerization liquid containing a large amount of unreacted styrenic monomer is sent to the main polymerization line where the next tubular reactor is connected in series, the unreacted styrene-based monomer in the pre-stage of the main polymerization line is continuously polymerized. The heat generated by the polymerization becomes extremely large, and stable control of the polymerization temperature becomes difficult. This destabilizes the dispersed state of the rubbery polymer particles initially generated,
As a result, partially large rubbery polymer particles are generated, which impairs the gloss of the product. Such a phenomenon becomes inevitable as the reactor is scaled up, even if it is not affected in a small scale reactor.

[0013]

[Means for Solving the Problems] In view of such a situation,
As a result of intensive studies by the present inventors, JP-A-63-3051
In carrying out the method described in Japanese Patent Publication No. 5 No. 5, by incorporating a reactor having a structure for dynamic mixing between a raw material supply line and an initial polymerization line, and prepolymerizing in the reactor under specific conditions, The inventors have found that the present invention is excellent in impact strength and gloss, and that the gloss gradient can be made relatively small, and completed the present invention.

That is, the present invention provides a styrene monomer in the presence of polybutadiene and / or styrene-butadiene copolymer rubber, a. Raw material supply line (I) and b. Continuing from the raw material supply line (I), a plurality of mixing elements having no moving parts are fixed inside 1
Initial polymerization line (II) consisting of more than one ring reactor
And c. A main polymerization line (III) consisting of one or more annular reactors continuing from the initial polymerization line (II) and having fixed therein a plurality of mixing elements with no moving parts.
And d. Initial polymerization line (II) and main polymerization line (III)
A polymerization line constituted by a reflux line (IV) that branches back into the initial polymerization line (II) between and is used for the majority of the initial polymerization liquid stream exiting the initial polymerization line (II). IV) while refluxing, while the non-refluxed initial polymerization liquid stream is polymerized in the main polymerization line (III) to produce an impact-resistant styrenic resin by continuous bulk polymerization (hereinafter referred to as a static mixing reactor). In the abbreviated method of producing the impact-resistant styrene resin used), polybutadiene and / or styrene-butadiene copolymer rubber is used at 5 ° C at 5 ° C.
The viscosity of the styrene solution by weight is 10 to 50 cps, and
It is characterized in that a reactor having a structure for dynamic mixing is incorporated between the raw material supply line (I) and the initial polymerization line (II), and prepolymerization is carried out while performing dynamic mixing in the reactor. In the continuous bulk polymerization method of impact-resistant styrenic resin and the method of producing impact-resistant styrene-based resin using the static mixing reactor, between the raw material supply line (I) and the initial polymerization line (II) A continuous bulk polymerization method of impact-resistant styrene-based resin, characterized in that a stirring type reactor having double-helical stirring blades is incorporated and prepolymerization is carried out while dynamically mixing in the reactor. In a method for producing an impact resistant styrene resin using a mixing reactor, a reactor having a dynamic mixing structure is incorporated between a raw material supply line (I) and an initial polymerization line (II), At Reynor Continuous bulk polymerization method of impact-resistant styrene-based resin, characterized by preliminarily polymerizing while performing dynamic mixing under the condition that the number is 2800 to 4500, and impact-resistant styrene using the static mixing reactor In the method for producing a resin-based resin, the polybutadiene and / or styrene-butadiene copolymer rubber has a 5 wt% styrene solution viscosity at 25 ° C. of 10 to 50 cps, and is between the raw material supply line (I) and the initial polymerization line (II). In which a stirring reactor having a double helical stirring blade was incorporated, and the Reynolds number in the reactor was 2800 to 45.
The present invention relates to a continuous bulk polymerization method for impact-resistant styrenic resin, which comprises preliminarily polymerizing while dynamically mixing under the condition of 00.

The present invention will be described in detail below. The steps of the polymerization method of the present invention will be specifically described with reference to FIG. 1. First, a mixture of polybutadiene and / or styrene-butadiene copolymer rubber and a styrene-based monomer is dynamically mixed from a raw material supply line (I). It is introduced into a structured reactor (2) to carry out prepolymerization. The polymerization liquid passed through the reactor having the structure for dynamic mixing is then subjected to the initial polymerization line (II).
And the initial polymerization is carried out. Initial polymerization line (I
The outlet of I) is divided into two parts, and most of the prepolymerized polymerization liquid is returned to the initial polymerization line (II) through the reflux line (IV), and the initial polymerization line (II) and the reflux line (IV). ) And a circle formed by (hereinafter referred to as a circulation polymerization line). The remaining polymerization liquid flows into the main polymerization line (III) and undergoes main polymerization there.

The annular reactor referred to in the present invention means an annular reactor in which a plurality of mixing elements having no moving parts are fixed. The mixing element means, for example, an element that mixes the polymerization liquid by dividing the flow of the polymerization liquid flowing into the pipe and changing the flow direction and repeating division and merging. In the present invention, for example, SMX type, S
MR type Sulzer type tubular mixer, Kenix type static mixer, Toray type tubular mixer, USP4
The tubular reactor described in No. 275177 can be preferably applied.

A stirred reactor is suitable as the reactor having a structure for dynamic mixing used in the present invention. Dynamic mixing is especially important in determining the particle size of the rubbery polymer being dispersed.

In the present invention, in order to reduce the shear applied to the prepolymerization liquid and to narrow the particle size distribution of the rubbery polymer to reduce the gloss gradient caused by the spread of the particle size distribution of the rubbery polymer. Then, a Reynolds number in an appropriate range is selected.

The optimum range of the Reynolds number varies depending on the scale of the plant, that is, the production capacity of the plant. That is, in a pilot plant, it is usually 10
It may be 0-250, but one series produces 20,000t or more per year.
In the case of a commercial scale of about 60,000t, 120-1
The Reynolds number at 38 ° C. is preferably 2800 to 4500. Above all, in order to make the distribution of the particle size of the rubbery polymer extremely narrow without adding extra shear to the prepolymerization liquid, the polymerization liquid in the reactor is kept under the initial polymerization temperature, for example, 120 to 138 ° C. Reynolds number is 3100 to 430
It is preferably 0.

The prepolymerization in a reactor having a structure for dynamic mixing is usually carried out so that the polymerization conversion rate of the styrenic monomer at the outlet of the reactor is 10 to 28% by weight. Among them, the range of 14 to 24% by weight is preferable.

As the reactor having the structure for dynamic mixing used in the present invention, for example, a tank type or column type reactor having an agitator capable of providing dynamic mixing in the above range can be applied. An anchor type, turbine type, screw type, double helical type, etc. can be used for the stirring blade. In particular, in the initial polymerization carried out in the present invention, a reactor using a double-helical type is particularly preferable because it can efficiently disperse the rubbery polymer and hence can improve the strength and reduce the gloss gradient.

In the circulation polymerization line used in the present invention, the polymerization conversion rate of the styrene-based monomer at the outlet of the circulation polymerization line is usually 35 to 55% by weight, and the generation of partially large rubbery polymer particles. It is preferably 40 to 50% by weight from the viewpoint that the gloss of the product can be improved by pressing. In this case, the polymerization temperature in the circulation polymerization line is suitably 130 to 145 ° C.

Since the particles of the rubbery polymer in the polymerization solution are stabilized in this region and the particle size is also fixed, the reflux ratio R of the polymerization solution in the circulation polymerization line and the polymerization conversion of the styrenic monomer. Rate is an important factor. The reflux ratio R is the initial flow rate from the circulation line to the main polymerization line (III), where F ₁ (l / hour) is the flow rate of the initial polymerization liquid flowing back into the circulation line without flowing to the main polymerization line (III). Flow rate of polymerization liquid F ₂
(L / hour), R = F ₁ / F ₂ is usually 3 to 15
Particularly, the range of R = 5 to 10 is particularly preferable in that the pressure loss in the tubular reactor is small, the rubbery polymer particles produced are stable, and the particle size can be reduced.

The polymerization liquid polymerized in the circulation polymerization line is then supplied to the main polymerization line (III), and usually 140-
At a reaction temperature of 170 ° C, the conversion rate of styrene monomer is 70.
Polymerization is continuously carried out until the content becomes ˜90 wt%.

Next, the polymerization liquid is subjected to decompression in a devolatilization tank under reduced pressure to remove unreacted monomers and a solvent, and then pelletized to give a target impact-resistant styrene resin. Initial polymerization line (II) and main polymerization line (III)
The number of tubular reactors incorporated in is not particularly limited because it varies depending on the length and the structure of the mixing element in the case of the tubular reactor as described above, but 4 to 15 tubular reactors having 4 or more mixing elements, Preferably, 6 to 10 are used in combination. Of these, the number of tubular reactors incorporated in the initial polymerization line (II) is usually 1 to 1.
The number is 0, preferably 2 to 6.

Typical examples of the polybutadiene and styrene-butadiene copolymer rubber used in the present invention include polybutadiene rubber, styrene-butadiene copolymer rubber, styrene-butadiene-styrene block copolymer rubber and the like. Among them, 5 wt% styrene solution viscosity (5% SV) is excellent in that the particle size is small and the gloss and impact resistance are excellent. ) Is 10-50
Polybutadiene and styrene-butadiene copolymer rubbers with cps are preferred. Among them, polybutadiene and styrene-butadiene copolymer rubber having a 5 wt% styrene solution viscosity (5% SV) of 15 to 30 cps are preferable in order to further reduce the gloss gradient. Among the styrene-butadiene copolymer rubbers, styrene is 1 to 10% by weight.
And 90 to 99% by weight of butadiene are preferable, and the bonding mode of styrene and butadiene may be either random bonding or block bonding.

The content of the rubbery polymer in the resin depends on the resin component.
It is usually within the range of 20 parts by weight per 100 parts by weight. The average rubber particle size in the impact-resistant styrenic resin obtained in the present invention is usually 0.5 to 2.0 μm, and the range of 0.7 to 1.0 μm is preferable in order to remarkably improve gloss and gloss gradient.

The styrenic monomer used in the present invention is a generic term for styrene, α-methylstyrene, styrene derivatives in which the hydrogen atom of the benzene nucleus is replaced by a halogen atom or an alkyl group having 1 to 4 carbon atoms. It is a thing. Typical examples of the styrene-based monomer include styrene, o-chlorostyrene, p-chlorostyrene, p
-Methylstyrene, 2,4-dimethylstyrene or t-
Butyl styrene and the like, with styrene being most preferred.

In the present invention, another monomer copolymerizable with the styrene-based monomer may be used in combination with the styrene-based monomer. In the bulk polymerization in the present invention, it is possible to use an appropriate amount of solvent for adjusting the viscosity of the polymerization liquid. Examples of the solvent include toluene, ethylbenzene, xylene and the like. The amount of the solvent used is usually within the range of not more than 20 parts by weight with respect to 100 parts by weight of the raw material liquid containing the rubbery polymer and the styrene monomer.

The feed liquid used in the present invention may, if necessary, be a known organic peroxide such as 1,1-di-t-butylperoxycyclohexane which gives out free radicals when decomposed as a polymerization initiator. , T-butylperoxybenzoate, di-t-butylperoxide, t-butylperoxyisopropyl carbonate and the like can also be used. Further, if necessary, a known additive such as a plasticizer such as mineral oil, an antioxidant, a chain transfer agent, a long-chain fatty acid, a release agent such as an ester or a metal salt thereof, and a known additive such as silicone oil may be used in combination. Is also good.

[0031]

EXAMPLES The present invention will be described more specifically by showing Examples and Comparative Examples below. However, all parts in the examples are parts by weight, and% are% by weight except for gloss values.

The physical property values in the examples were measured as follows. (1) Average particle size of rubbery polymer in resin The volume average particle size was determined by a Coulter counter (TA-II type manufactured by Coulter Co., Ltd.) using an electrolytic solution containing dimethylformamide and ammonium thiocyanate.

(2) Izod impact value Based on JIS K-6871. (3) Gloss and gloss gradient A dumbbell test piece was manufactured by injection molding, and the gloss of the plane on the gate side and the plane on the end side of the test piece was measured according to JIS Z-874.
It measured based on 1 (incident angle 60 degrees). Next, (gloss on the flat surface on the gate side) / (gloss on the side on the terminal side) was calculated to obtain a gloss gradient.

Example 1 In this example, an apparatus arranged as shown in FIG. 1 was used. The raw material liquid containing the styrene monomer, the rubbery polymer and the solvent is supplied by the plunger pump in the raw material supply line (I).
By (1), it is sent to 20 stirred reactors (2) to undergo initial polymerization under dynamic mixing. Then the initial polymerization liquid is the gear pump
It is sent to the circulation polymerization line by (3). The circulation polymerization line is a tubular reactor with an inner diameter of 2.5 inches in order from the inlet (SGE type static mixer with 30 mixing elements manufactured by Gebrüder-Sulzer in Switzerland, see Figure 2) (4) (5) (6) initial polymerization It comprises a line (II) and a reflux line (IV) consisting of a gear pump (7) for circulating the polymerization liquid. An outlet leading to the main polymerization line (III) is provided between the tubular reactor (6) and the gear pump (7). To the main polymerization line, tubular reactors (8), (9) and (10) and a gear pump (11) similar to the above are connected in series from the inlet.

Polybutadiene 7 with 5% SV of 45 cps
Parts, 93 parts of styrene monomer and 6 parts of ethylbenzene were prepared, and bulk polymerization was continuously carried out under the following conditions using the above apparatus. However, a reactor using anchor type stirring blades as shown in FIG. 4 was used as the stirring reactor.

Continuous supply of raw material liquid 12
/ Hour Reaction temperature in stirred reactor (2) 134 ° C Reynolds number in stirred reactor (2) Re = 130 Reaction temperature in circulating polymerization line 136 ° C Reaction temperature in non-circulating polymerization line 150-170 ° C Here, the number of Reynolds in the stirred reactor (2) is calculated by the following formula 1
It was calculated in. Re = (d ² Nρ) / μ Equation 1 (In Equation 1, d is the diameter of the stirring blade (m), N is the rotation speed of stirring (r / sec), and ρ is the stirring reactor (2). The density (kg / cm ³ ) and μ of the reaction liquid of (1) and (μ) respectively represent the viscosity (kg / m · sec) of the reaction liquid in the stirring reactor (2).

The obtained polymerization liquid was heated to 230 ° C. in a heat exchanger, volatile components were removed under a reduced pressure of 50 mmHg, and then the mixture was melted and kneaded by an extruder and pelletized to form a high impact styrene type resin composition of the present invention. A resin was obtained. Table 1 shows the polymerization conditions and measurement results of various physical properties.

Example 2 Using a raw material liquid consisting of 8 parts of low cis polybutadiene having a 5% SV of 25 cps, 92 parts of styrene monomer and 6 parts of ethylbenzene, the number of Reynolds in the stirred reactor (2) was 2
An impact-resistant styrene-based resin of the present invention was obtained in the same manner as in Example 1 except that the ratio was changed to 10. Table 1 shows the polymerization conditions and measured values of various physical properties.

Example 3 The stirring blade of the stirring reactor (2) was changed from an anchor type to a double helical type as shown in FIG. 5 so that the number of Reynolds in the stirring reactor (2) was 150. An impact resistant styrene resin of the present invention was obtained in the same manner as in Example 1 except for the above. As a result, a resin having a small gloss gradient and good appearance was obtained. Table 1 shows the polymerization conditions and measurement results of various physical properties.

Example 4 Styrene containing 5% styrene and 5% SV at 25 cps instead of low cis polybutadiene having a 5% SV of 25 cps.
The butadiene copolymer rubber was used, and instead of the anchor-type stirring reactor, the double-helical stirring reactor of Fig. 5 was used, and the Reynolds number in the stirring reactor (2) was 214. An impact resistant styrene resin of the present invention was obtained in the same manner as in Example 2 except for the above. Table 1 shows the polymerization conditions and measurement results of various physical properties.

Example 5 Instead of 20 stirring type reactors (2) having anchor type stirring blades, 10 m ³ stirring type reactors having double helical type stirring blades were used, and instead of a tubular reactor having an inner diameter of 2.5 inches. A tubular reactor with an inner diameter of 900mm (SMR type static mixer manufactured by Gebrüder-Sulzer, Switzerland)
2)) and the feed amount of the raw material liquid is 6000 l /
Change to time and the number of Reynolds in the stirred reactor (2) is 3
An impact-resistant styrenic resin of the present invention was obtained in the same manner as in Example 2 except that 950 was used. Table 1 shows the polymerization conditions and the measurement conditions of various physical properties.

Example 6 The impact-resistant styrene-based resin of the present invention was prepared in the same manner as in Example 5 except that the stirring speed of the stirring reactor (2) was adjusted so that the number of Reynolds therein was 3950. A resin was obtained. Table 1 shows the polymerization conditions and the measurement conditions of various physical properties.

Comparative Example 1 A raw material solution was pumped through a gear pump without using the stirring reactor (2).
An impact-resistant styrenic resin was obtained in the same manner as in Example 1 except that (3) was used and directly fed to the circulation polymerization line. In this case, the polymerization conversion rate of the styrene-based monomer at the outlet of the circulation polymerization line was 25%. Table 1 shows the polymerization conditions and measurement results of various physical properties.

Comparative Example 2 The raw material liquid was gear pumped without using the stirring reactor (2).
(3) is directly supplied to the circulation polymerization line, and the reflux ratio R in the circulation polymerization line is 12 and the reaction temperature is 13
An impact resistant styrene resin was obtained in the same manner as in Example 1 except that the temperature was changed to 0 ° C.

In this case, the polymerization conversion rate of the styrene-based monomer at the outlet of the circulation polymerization line was as low as 16%, and the heat generation in the non-circulation polymerization line thereafter increased, so that the cooling capacity of the tubular reactor was close to the limit. And the reaction temperature was maintained. Table 1 shows the polymerization conditions and measurement results of various physical properties.

Comparative Example 3 A raw material solution was pumped through a gear pump without using the stirring reactor (2).
(3) is directly fed to the circulation polymerization line, and the reflux ratio R in the circulation polymerization line is 10 and the reaction temperature is 13
An impact resistant styrene resin was obtained in the same manner as in Example 2 except that the temperature was changed to 1 ° C. In this case, the polymerization conversion rate of the styrene-based monomer at the outlet of the circulating polymerization line was as low as 18%, and the heat generation in the non-circulating polymerization line thereafter increased, so the cooling capacity of the tubular reactor was raised to the limit. The reaction temperature was maintained. Table 1 shows the polymerization conditions and the measurement conditions of various physical properties.

Comparative Example 4 The raw material liquid was directly supplied to the circulating polymerization line using the Kia pump (3) without using the stirring type reactor (2), and 5% SV was used.
An impact resistant styrene resin was obtained in the same manner as in Example 1 except that low cis polybutadiene having a viscosity of 85 cps was used.
Table 1 shows the polymerization conditions and the results of various physical properties.

Comparative Example 5 The raw material liquid was directly supplied to the circulation polymerization line using the gear pump (3) without using the stirring reactor (2), and 5% SV was used.
An impact-resistant styrene-based resin was obtained in the same manner as in Example 1 except that a styrene-butadiene copolymer rubber containing 60 cps and containing 5% styrene was used. Table 1 shows the polymerization conditions and measurement results of various physical properties.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

The impact-resistant styrenic resin obtained by the polymerization method of the present invention has excellent gloss and impact strength, and a molded article having a small gloss gradient can be obtained. That is, the characteristic feature of the molded article obtained by injection molding of the resin is that the ratio of glossiness on the gate side and the end side is as small as 1.01 to 1.13. In the conventional technique, it is necessary to previously prepare a polymerization liquid having different rubber particle diameters and mix them in a polymerization vessel, or to blend them by an extruder, so that it is inevitable that productivity is lowered and cost is increased. On the other hand, the present invention skillfully utilizes dynamic mixing and static mixing particularly in the region where rubber particles are formed in the initial stage of polymerization, and is advantageous in that particle size control and strength increase are simultaneously brought out. It can be said that it is a polymerization method.

The resin obtained by the present invention is suitable for molded articles requiring a surface gloss comparable to ABS resin in the fields of low-voltage housings and sundries.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a polymerization apparatus used in the polymerization method of the present invention,

[Fig. 2]

2 and 3 are partially omitted perspective views of an annular reactor in which a plurality of mixing elements are fixed.

FIG. 4 is a schematic view of a stirred reactor having anchor type stirring blades,

FIG. 5 is a schematic view of a stirring reactor having a double helical stirring blade. (I): Raw material supply line (II): Initial polymerization line (III): Main polymerization line (IV): Reflux line (1): Plunger pump (2): Stirring reactor (3): Gear pump (4) , (5), (6): tubular reactor (7): gear pump (8), (9), (10): tubular reactor (11): gear pump

Claims (16)

[Claims] 1. A styrenic monomer in the presence of polybutadiene and / or styrene-butadiene copolymer rubber, a. Raw material supply line (I) and b. Continuing from the raw material supply line (I), a plurality of mixing elements having no moving parts are fixed inside 1
Initial polymerization line (II) consisting of more than one ring reactor
And c. A main polymerization line (III) consisting of one or more annular reactors continuing from the initial polymerization line (II) and having fixed therein a plurality of mixing elements with no moving parts.
And d. Initial polymerization line (II) and main polymerization line (III)
A polymerization line constituted by a reflux line (IV) that branches back into the initial polymerization line (II) between and is used for the majority of the initial polymerization liquid stream exiting the initial polymerization line (II). IV) through which the initial polymerization liquid stream which has not been refluxed is polymerized in the main polymerization line (III) to produce an impact-resistant styrenic resin by continuous bulk polymerization, in which polybutadiene and / or styrene-
A reactor having a butadiene copolymer rubber having a 5 wt% styrene solution viscosity at 25 ° C. of 10 to 50 cps and having a structure for dynamic mixing between the raw material supply line (I) and the initial polymerization line (II) is used. A continuous bulk polymerization method of impact-resistant styrenic resin, characterized in that it is preliminarily polymerized while being incorporated, and dynamically mixed in the reactor. 2. Polybutadiene and / or styrene-
A reactor having a butadiene copolymer rubber having a 5 wt% styrene solution viscosity at 25 ° C. of 15 to 30 cps and having a structure for dynamic mixing between the raw material supply line (I) and the initial polymerization line (II) is used. The polymerization method according to claim 1, wherein the polymerization is carried out by preliminarily incorporating, and in addition, dynamically mixing in the reactor. 3. The polymerization method according to claim 1, wherein the polymerization conversion of the styrene-based monomer at the outlet of the reactor having a structure for dynamic mixing is performed until it becomes 14 to 24% by weight. 4. The polymerization conversion of styrene monomer at the outlet of the reactor having a structure for dynamic mixing is 10 to 28% by weight,
And from the initial polymerization line (II) to the main polymerization line (II
The polymerization method according to claim 1 or 2, wherein the polymerization conversion rate of the styrene-based monomer at the outlet of the initial polymerization line (II) in the liquid flowing into I) is 35 to 55% by weight. 5. A styrenic monomer in the presence of polybutadiene and / or styrene-butadiene copolymer rubber, a. A raw material supply line (I), b. Continuing from the raw material supply line (I), a plurality of mixing elements having no moving parts are fixed inside 1
Initial polymerization line (II) consisting of more than one ring reactor
And c. A main polymerization line (III) consisting of one or more annular reactors continuing from the initial polymerization line (II) and having fixed therein a plurality of mixing elements with no moving parts.
And d. Initial polymerization line (II) and main polymerization line (III)
A polymerization line constituted by a reflux line (IV) that branches back into the initial polymerization line (II) between and is used for the majority of the initial polymerization liquid stream exiting the initial polymerization line (II). IV) while refluxing, while the non-refluxed initial polymerization liquid stream is polymerized in the main polymerization line (III) to produce impact-resistant styrenic resin by continuous bulk polymerization. Impact-resistant styrene characterized by incorporating a stirring type reactor having a double-helical stirring blade between the initial polymerization line (II) and preliminarily polymerizing while performing dynamic mixing in the reactor. Continuous bulk polymerization method of resin. 6. The polymerization conversion rate of the styrene-based monomer at the outlet of the stirring-type reactor having a double-helical stirring blade is 14
The polymerization method according to claim 5, wherein the polymerization method is carried out up to 24% by weight. 7. The polymerization conversion rate of the styrene-based monomer at the outlet of the stirring type reactor having a double helical stirring blade is 10
˜28% by weight, and the polymerization conversion rate of the styrene-based monomer at the outlet of the initial polymerization line (II) in the liquid flowing from the initial polymerization line (II) into the main polymerization line (III) is 35 to 55% by weight. 6. The polymerization method according to claim 5, wherein 8. A styrenic monomer in the presence of polybutadiene and / or styrene-butadiene copolymer rubber, a. A raw material supply line (I), b. Continuing from the raw material supply line (I), a plurality of mixing elements having no moving parts are fixed inside 1
Initial polymerization line (II) consisting of more than one ring reactor
And c. A main polymerization line (III) consisting of one or more annular reactors continuing from the initial polymerization line (II) and having fixed therein a plurality of mixing elements with no moving parts.
And d. Initial polymerization line (II) and main polymerization line (III)
A polymerization line constituted by a reflux line (IV) that branches back into the initial polymerization line (II) between and is used for the majority of the initial polymerization liquid stream exiting the initial polymerization line (II). IV) while refluxing, while the non-refluxed initial polymerization liquid stream is polymerized in the main polymerization line (III) to produce impact-resistant styrenic resin by continuous bulk polymerization. A reactor having a structure for dynamic mixing was installed between the initial polymerization line (II) and the Reynolds number in the reactor was 2800-4.
A continuous bulk polymerization method of impact-resistant styrene resin, characterized by preliminarily polymerizing while dynamically mixing under the condition of 500. 9. The polymerization method according to claim 8, wherein the Reynolds number in the reactor having a structure for dynamic mixing is 3100 to 4300. 10. The polymerization method according to claim 8 or 9, wherein the polymerization conversion rate of the styrene-based monomer at the outlet of the reactor having a structure for dynamic mixing is 14 to 28% by weight. 11. The polymerization conversion rate of the styrene-based monomer at the outlet of the reactor having a structure for dynamic mixing is 10 to 28% by weight.
From the initial polymerization line (II) to the main polymerization line (I
Initial polymerization line (II) in the stream entering II)
The polymerization method according to claim 8 or 9, wherein the polymerization conversion rate of the styrene-based monomer at the outlet is 35 to 55% by weight. 12. Polybutadiene and / or styrene-
A styrene monomer in the presence of a butadiene copolymer rubber, a. A raw material supply line (I), b. Continuing from the raw material supply line (I), a plurality of mixing elements having no moving parts are fixed inside 1
Initial polymerization line (II) consisting of more than one ring reactor
And c. A main polymerization line (III) consisting of one or more annular reactors continuing from the initial polymerization line (II) and having fixed therein a plurality of mixing elements with no moving parts.
And d. Initial polymerization line (II) and main polymerization line (III)
A polymerization line constituted by a reflux line (IV) that branches back into the initial polymerization line (II) between and is used for the majority of the initial polymerization liquid stream exiting the initial polymerization line (II). IV) through which the initial polymerization liquid stream which has not been refluxed is polymerized in the main polymerization line (III) to produce an impact-resistant styrenic resin by continuous bulk polymerization, in which polybutadiene and / or styrene-
The butadiene copolymer rubber has a 5 wt% styrene solution viscosity at 25 ° C. of 10 to 50 cps, and a stirring type having a double-helical stirring blade between the raw material supply line (I) and the initial polymerization line (II). A continuous bulk polymerization method for impact-resistant styrenic resin, characterized in that prepolymerization is carried out by incorporating a reactor and performing dynamic mixing under the condition that the Reynolds number is 2800 to 4300 in the reactor 2. 13. The polybutadiene and / or styrene-butadiene copolymer rubber has a 5 wt% styrene solution viscosity at 25 ° C. of 15 to 30 cps, and between the raw material supply line (I) and the initial polymerization line (II). Incorporating a stirring reactor with double-helical stirring blades,
The polymerization method according to claim 12, wherein prepolymerization is carried out while performing dynamic mixing in the reactor 2 under the condition that the Reynolds number is 2800 to 4300. 14. The polymerization method according to claim 12, wherein the Reynolds number in the stirring reactor having a double helical stirring blade is 3100 to 4300. 15. The polymerization conversion rate of the styrene-based monomer at the outlet of the stirring type reactor having a double helical stirring blade is 1
The method according to claim 12, 13 or 1 is performed until the content becomes 4 to 24% by weight.
4. The polymerization method according to 4. 16. The polymerization conversion rate of the styrene-based monomer at the outlet of the stirring-type reactor having a double-helical stirring blade is 1
0 to 28% by weight, and the polymerization conversion rate of the styrene-based monomer at the outlet of the initial polymerization line (II) in the liquid flowing from the initial polymerization line (II) to the main polymerization line (III) is 35 to 55% by weight. %, 15. The polymerization method according to claim 12, 13 or 14.