JPH03712A - Preparation of rubber-modified styrenic resin and resin composition - Google Patents

Abstract

PURPOSE:To obtain the title resin with excellent mechanical strength and appearance by continuously polymerizing a styrenic monomer and a rubbery polymer, continuously polymerizing a styrenic monomer on the other and continuously mixing and polymerizing both products at a specified condition. CONSTITUTION:A raw material soln. wherein a styrenic monomer (e.g. styrene) and a rubbery polymer (e.g. polybutadiene rubber) are the main components is continuously fed in the first reactor of a completely mixing type and is polymerized therein. Separately a raw material wherein a styrenic monomer (e.g. styrene) is the main component is continuously fed in the second reactor for polymn. and is polymerized therein. Products taken out of both reactors are introduced into the third reactor which has a residence time shorter than that of the first reactor and is of a completely mixing type. Polymn. thereof is performed within a range where conversion of the polymn. from the monomer to a polymer does not exceed 30% and at the same time, the rubbery polymer is granulated. Then, the mixture is introduced into a plug flow type reactor consisting of one or a plurality of reactors connected in series and having the number of corresponding tanks in a model of a completely mixing tank line of 15 or larger and the conversion of polymn. is elevated to 85-95%. Thereafter, an unreacted monomer is removed from the reaction product by evaporation.

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides an improved method for producing a rubber-modified styrenic resin, and a rubber-modified styrenic resin composition, particularly for improved mechanical strength such as impact resistance and gloss. The present invention relates to a continuous production method and resin composition of a rubber-modified styrenic resin with improved appearance.

(Prior art) In order to produce a rubber-modified styrenic resin with excellent impact resistance and improved appearance, the particle size of the rubber particles dispersed in the resin is adjusted to an appropriate size. In addition to having to adjust the distribution to an appropriate range, the rubber particles must contain an appropriate amount of polystyrene.

The polystyrene contained in the rubber particles includes graphite polystyrene that is chemically bonded to the rubber, and occluded polystyrene that is not chemically bonded to the rubber but cannot be separated from the rubber particles by the normal dissolution-re-precipitation method. There is (oklunoyon). Grafted polystyrene has the role of an emulsifier that allows rubber particles to be stably dispersed in the polystyrene matrix, but occluded polystyrene also increases the volume fraction of rubber particles and prevents excessive deformation of the rubber phase. It plays an important role in preventing

As a method for producing such rubber-modified styrenic resins, a batch-type bulk-suspension two-stage polymerization method is widely practiced. Since this patch-type polymerization is carried out using the plug 70-, the size of the individual rubber particles can be brought close to a constant size if the mixing in the previous bulk polymerization stage is properly achieved. *This reaction is carried out in the subsequent suspension polymerization to a point where the polymerization conversion rate is close to 100%, so there are many opportunities for the rubber and styrene monomer to react (
, the individual rubber particles can contain modest amounts of polystyrene.

However, this patch method has inherent drawbacks: (a) it requires large amounts of auxiliary agents such as water and suspension stabilizers; (Iff) it requires manpower as it involves many operations that make automation difficult; (c) Even after cooling, separating water and resin beads, and drying, it is necessary to pelletize them in order to make a product resin, which requires a large amount of energy. (d) Chemicals such as auxiliaries (e) Auxiliary agents such as suspension stabilizers remain as impurities in the product resin, causing appearance defects such as silver streaks, etc. , there are still issues to be resolved.

Therefore, various continuous production methods have been proposed, one of which is the use of multiple complete mixing reactors (usually 3 to 4).
It is known to use devices connected in series. However, this method produces a fairly wide distribution of residence times, resulting in differences in the reaction time between individual rubber particles and styrene.
A situation arises in which a suitable amount of polystyrene is not contained in rubber particles with a short residence time, and fairly strong stirring is required to control the reaction in the reactor.
There are restrictions due to the handling of highly viscous materials, and there is a problem that the polymerization conversion rate cannot be increased even in the final reactor. For this reason, it is quite difficult to obtain a product of the same quality as that obtained by the patch method using the continuous method. For the above-mentioned reasons, problems remain due to the wide particle size distribution of the rubber particles and the presence of rubber particles that do not contain polystyrene to the desired extent.

(The invention tries to solve! 1311) In order to solve the above problems, it is thought that it is necessary to combine a plug flow type reactor that can be used for continuous polymerization and to increase the reaction rate to a high polymerization conversion rate. However, there are technical difficulties associated with this. The following points can be cited as such problems.

■ Before rubber is dispersed as particles, the rubber phase is a continuous phase and exhibits rubber viscosity, and if it is not constantly subjected to shear from stirring, the retained portion will adhere to the vessel walls, and the polymerization reaction will be blocked by the powder. .

Polymerization reactions in such a state exhibiting rubber viscosity can be handled in a complete mixing type reactor, but reactions that require uniform shearing at any location in the reactor can be handled in a plug flow type reactor. It is very difficult to make it work.

■ A high polymerization conversion rate is desirable, but in addition to the accompanying difficulty in handling highly viscous materials, as the polymerization conversion rate increases, the reaction rate decreases relatively as unreacted monomer decreases. Therefore, a large volume reactor and long residence time are required. Hence the reaction of the patch formula! l) Continuing the process not only causes problems in the quality of the resulting resin composition, but also unnecessarily increases the construction cost of the equipment.

(Means for Solving Problem W) The present invention solves the above problems and provides a method for continuously producing a resin having the excellent quality of rubber-modified styrenic resin produced by a batch method. According to the present invention, the first purpose is to continuously charge a raw material solution mainly consisting of a styrenic monomer and a rubbery polymer into a complete mixing type first reactor for polymerization. The reaction was carried out, and on the other hand, raw materials mainly composed of styrene monomers were continuously charged into a second reactor of a type that can be used for polymerization reactions, and a polymerization reaction was carried out. From the reactor,
The products that are continuously derived from each are simultaneously introduced into a complete mixing type third reactor having a shorter residence time than the first reactor to proceed with the polymerization reaction, and from this third reactor the products are continuously introduced. The resulting product is introduced into a plug-flow reactor to measure the polymerization conversion rate, and then unreacted monomers are devolatilized from the reaction product to produce rubber-modified styrene resin. In this continuous production method, the rubber-like polymer in the product derived from the third reactor is already granulated, but at the outlet of the third reactor, the monomer is separated from the rubber-like polymer. Polymerization is proceeding within a range where the polymerization conversion rate to the polymer does not exceed 30%, and the above-mentioned plug flow reactor is composed of one reactor or multiple reactors connected in series, and is a complete mixing tank. The number of equivalent tanks in the row model is 15 or more,
In this plug-flow type reactor, a polymerization conversion rate of 85 to 95% is achieved by a method characterized by polymerization.

Another object of the present invention is to provide a rubber-modified styrenic resin that is produced by a continuous production method but has superior quality equivalent to or better than that produced by a batch method. In particular, this purpose is to carry out a polymerization reaction by continuously charging a raw material solution mainly consisting of a styrene monomer and a rubbery polymer into a complete mixing type first reactor, in accordance with the present invention. A raw material mainly composed of styrene monomers is continuously charged into a second reactor of a type that can be used for polymerization reaction, and a polymerization reaction is carried out. The polymerization reaction is proceeded by simultaneously introducing the product derived from the above-mentioned first reactor into a complete mixing type third reactor having a shorter residence time than the first reactor, and the product is continuously derived from this third reactor. The resulting product is introduced into a plug flow reactor consisting of one reactor or multiple reactors connected in series, and the equivalent number of reactors is 15 or more in a complete mixing tank array model to increase the polymerization conversion rate. A rubber-like polymer that is continuously produced by increasing the reaction temperature and then devolatilizing unreacted monomers from the reaction product, and that is formed into particles with a density of 0.96 or less at 25 ° C. Achieved by a rubber-modified styrene composition having substantially no fat composition.

In the present invention, the styrenic monomer constituting the raw material liquid charged into the first reactor and the second reactor includes, for example, styrene, a-methylstyrene, fulkyl-substituted styrene such as 1)-methylstyrene, and chlorine. One type or a mixture of two or more types of styrene yarns conventionally known for producing rubber-modified styrenic resins, such as halogen-substituted styrene such as styrene, can be used. Among these,
Preferred is styrene.

In addition, a part of this styrenic monomer can be copolymerized with monomers such as acrylonitrile, maleic anhydride,
Methyl methacrylate, vinyl acetate, divinylbenzene, etc. ii! You can also change it.

Examples of the rubbery polymer in the raw material solution supplied to the #IJ1 reactor include natural rubber, styrene-butanoene rubber, polybutadiene, polyisoprene, nitrile rubber,
．． Examples include elastomeric block copolymers of 3-conjugated diene and styrene monomers, but preferred are polybutadiene, styrene-butadiene rubber, and polyisoprene.

The composition of the raw material solution mainly composed of these styrene monomers and rubbery polymers is usually 8 styrene monomers, 8 styrenic monomers,
3 to 20% by weight of rubbery polymer to 0 to 97% by weight;
Preferably, the rubber-like polymer is 5 to 18% by weight based on 82 to 95% by weight of the styrene monomer, and if necessary, aromatic carbonization consisting of toluene, quincylene, ethylbenzene, etc. alone or in a mixture of two or more thereof. Solvents such as hydrogen, for example 2
It can be used in a range up to 0% by weight.

If the amount of the solvent used exceeds 20% by weight, the polymerization rate will drop sharply, making it uneconomical. This raw material solution contains a small amount of polymerization initiator, such as tert-butyl peroxybenzoate, tert-butyl peroxyacetate, 1,1-butyl peroxycyclohexane, benzoyl peroxide, lauroyl peroxide, etc. Peroxide, azobisisobutyronitrile, etc. can also be added, and the impact strength can be increased or decreased by this.

In the present invention, the raw material solution mainly consisting of the styrene monomer and the rubbery polymer is polymerized in the first complete mixing reactor. Any stirring blade can be used as long as it can maintain a substantially uniform mixing state within the stirring blade, and preferred stirring blades include blades of helical ribbon, double helical ribbon, anchor type, and the like. In the case of helical ribbon type blades, a draft tube can be attached to further strengthen the vertical circulation within the reactor.

Generally, when a homogeneous raw material solution consisting of a styrene monomer and a rubbery polymer is polymerized, in the early stage of polymerization, the solution (resin phase) containing the styrene monomer and its polymer turns into a rubbery polymer. The rubber phase becomes a continuous phase and the resin phase becomes a dispersed phase.As the polymerization progresses, at a certain point, that is, the styrene polymer When the amount of the resin phase increases and the resin phase can no longer remain as a dispersed phase, so-called phase inversion occurs, in which the resin phase becomes a continuous phase and the rubber phase becomes a dispersed phase. Although it is possible to operate in any state in the first reactor, it is preferable to polymerize in a state in which the rubber phase becomes a dispersed phase and becomes particles, and the residence time in the first reactor is in the range of 1 to 6 hours. Preferably.

On the other hand, a styrene monomer is continuously charged and polymerized in a second reactor installed in parallel with the first reactor. The second reactor is not particularly limited in its type (it may be a complete mixing type reactor of the same type as the first reactor, as long as it is a reactor for polymerization reactions without stagnation and capable of temperature control). Although a reactor can be used, a plug flow type reactor such as a tubular reactor can also be used.

The streams continuously sent from the first reactor and the second reactor are sent to the #S3 reactor, which is a complete mixing type with a short residence time. This third reactor is functionally similar to the reactor described above, only smaller in size. Preferred shapes of the stirring blades provided in this reactor include helical ribbons, double helical ribbons, anchors, and the like.

In the case of helical ribbon type blades, a draft tube can be attached to further strengthen the vertical circulation within the reactor.

At the outlet of the third reactor, the rubber phase is in a dispersed phase state, that is, the rubbery polymer is already in a particulate state.

In the present invention, the residence time in the third reactor means that the polymerization liquid *U in the third reactor is continuously drawn out from the first reactor and the second reactor and introduced into the third reactor. It is the time value divided by the flow rate per unit time. The residence time in the third reactor is shorter than the residence time of the reaction liquid in the first reactor, and specifically, the preferred range is 0.34 to 0.7 hours. Outside this range, mixing may be insufficient or the viscosity may increase too much, resulting in insufficient stirring and heat removal, making it difficult to stabilize the rubber particles. In the J33 reactor, the residence time is short and the polymerization conversion rate is not dramatically increased.

Moreover, since the rubber-like polymer has already become particles, the first
When the streams of the reactor and the second reactor are combined, they should preferably be above, or very close to, if not above, the point of phase inversion at which the rubbery polymer becomes particulate, i.e. If the operation is carried out at a polymerization conversion rate at which the rubber-like polymer has already become particulate at the outlet of the first reactor, the polymerization conversion rate in the second reactor is such that the rubbery polymer has already been polymerized to the extent that this state is maintained. However, if the first reactor is operated at a polymerization conversion rate before phase inversion, then the polymerization conversion rate in the second reactor will be at least as high as that of phase inversion when the two streams are combined. must be kept somewhat high so as to exceed the rate.

The phase inversion point at which the rubbery polymer becomes particles depends on the volume ratio of the resin phase and the rubber phase.
This is because the composition is related to the polymerization 8 of the reactor. Even in this case, in order to achieve higher quality than that obtained in the batch method, the polymerization conversion rate of the tjS2 reactor must be
It is preferable that the polymerization conversion rate does not exceed the polymerization conversion rate of one reactor.

There is no particular critical point regarding the ratio of flows from the first and second reactors, but if the flow from the second reactor becomes too large, the rubber concentration in the feedstock solution fed to the first reactor will decrease. The ratio of flows from both reactors, respectively, is preferably in the range 3:1 to 71:3.

From the third reactor, an amount corresponding to the total amount sent from the first reactor and the second reactor is continuously taken out, and the polymerization conversion rate is increased in the next plug flow type reactor. As a vessel, a vessel in which a stirring chamber and a shell-and-tube type heat exchanger are fitted alternately, a vessel in which a cooling pipe and a stirrer are combined in a II&A vessel, etc. can be used. Plug 7 can also be used without an agitator if it is devised so that there is no so-called differential space.
0 - the equivalent number of tanks in the complete mixing tank array model is 1.
5 or more, it is common to have multiple plug 70-type rereactors connected in series, but economically it is not desirable to have a large number of them, so it is usually two. In a plug flow type reactor, which is preferred, the polymerization reaction is carried out at the outlet until the polymerization width ratio is in the range of 85 to 95%.

(Function) The present invention makes it possible to obtain a resin composition of a quality equivalent to or higher than that of a product produced by a patch polymerization reaction method, but this is achieved by satisfying the requirements constituting the production method of the present invention. , we will explain the significance of these requirements.

■ The method of the present invention uses rubber-modified styrenic resin! ! In the leaving process, the operation is repeated until the rubber phase becomes particles.
Polymerization was carried out in a FJII complete mixing reactor, and the 2N heterogeneous polymerization liquid from the first and second reactors was continued in a third complete mixing reactor with short residence time. The rubber particles are stirred and mixed at the same time, thereby stably producing homogeneous rubber particles in the end. The desired effect of the present invention cannot be obtained with one reactor without a second reactor, and
The effects of the present invention cannot be achieved even without a complete mixing type reactor with a short residence time. When rubber is granulated in the tJS1 reactor and immediately introduced into a plug flow reactor, some rubber particles in the final product have a density (at 25°C) of 0.96 or less. In view of this yIL actuality, it is thought that if the second reactor and the third reactor with a short residence time are omitted, some rubber particles will be produced in which polystyrene offfusion will not be sufficiently formed. Furthermore, in this case, the particle size distribution of the rubber particles is wide, which is considered to be one of the reasons why products of excellent quality cannot be obtained. Before introducing intermediate products into the vessel,
The problem cannot be solved simply by adding another complete mixing reactor, and even if an rIS2 reactor is installed in parallel with the first reactor, the two liquids from these reactors are simply combined to form a plug flow reactor. It is not enough to just send it to The reason for this is not clearly elucidated, but it is recognized for the first time that the two-liquid particles from the first and second reactors are virtually undetectable, and the particle size distribution of the rubber particles becomes considerably narrower. 2 with very different characteristics? [By effectively stirring and mixing the rubber particles, even if rubber particles have already been formed, the fusion and separation of the rubber particles will occur again, resulting in off-fluidization and uniform particle size. It is thought that the rubber particles can be stabilized by further proceeding with polymerization. Furthermore, when the two liquids are introduced into a plug flow type reactor without a third reactor, deposits such as polymer gel are generated in the plug flow type reactor, making it impossible to control the polymerization reaction.

■ After the rubber has become particulate, the polymerization process is relatively easy in a plug-flow reactor.

In a plug flow reactor, the polymerization conversion rate is 30%.
By increasing the amount from below to 85% or more, the grafting and offfusion of styrene to the granulated rubber particles is further promoted. Plug 70 with equivalent number of tanks of 15 or more in the complete mixing tank array model - If there is no plug, it is difficult to remove heat and add Wt as a reactor with a polymerization conversion rate of 30% or less at the inlet and 85% or more at the outlet. becomes. Furthermore, since it is difficult to control the polymerization reaction, molecular weight control is insufficient1, styrene grafting and offfusion are not uniformly carried out, and the density of the rubbery polymer in the resin composition is 0.9.
6 (25°C) or lower, resulting in a loss of quality of the product resin composition.

Although the upper limit of 15 or more equivalent tanks in the complete mixing tank array model in a plug flow reactor is not particularly critical, it is pointless to increase the number more than necessary, and usually up to about 40 is sufficient.

Keeping the polymerization conversion rate of the product entering the plug flow reactor from the complete mixing type third reactor to 30% or less not only means that the reaction under the plug 70- condition is prolonged as much as possible; The polymerization conversion rate of the product in the third reactor is 30
%, the particle size distribution of the rubber particles becomes unfavorable. It is also believed that the influence of commercial viscosity prevents the particles from coalescing or separating again.

If the polymerization conversion rate of styrene in the product at the final outlet of the plug-flow reactor is 85% or more, styrene grafts and occludone are naturally formed in all rubber particles, and Density at 25℃ 0.9
Substantially no rubber particles of 6 or less are produced. Increasing the styrene polymerization conversion rate of the product at the outlet of the plug-flow reactor to more than 95% requires a long polymerization reaction, which only leads to an increase in the size of the reactor. This is not preferable since it does not have the effect of improving the quality of the resin composition.

(Method for Measuring Density of Particulate Rubber-like Polymer) Prepare six 50-ton Erlenmeyer flasks, and pour 1 g of a rubber-modified styrenic resin composition sample into each flask. On the other hand, dimethylformamide (hereinafter abbreviated as DMF) and IN-
Prepare methyl-2-pyrrolidone (hereinafter abbreviated as NMP) reagents, use DMF alone as AF&, NMP alone as solution F, and mix both reagents in the proportions (weight ratio) shown in the table below. B liquid, C liquid, D liquid and E liquid
Make it into a liquid.

The numerical values in the m component of the table above indicate that the molecule is DMF.

The denominator indicates NMP, and the density is the value at 25°C.

Add 15118 ml of 5F solution to each of the flasks containing the above samples to dissolve and disperse the samples. The rubbery polymer particles in the sample resin are not soluble in the solvent. Once the polystyrene in the matrix portion is completely dissolved, each sample is transferred to a centrifugation cell. For the sample content remaining in the triangular 7 lath, a solution having the same composition as that used for dissolving it is used as a washing solution (15-8), and the sample content is transferred to a centrifugation substitute cell together with the solution produced by the washing. The cells were then centrifuged at a temperature of 25° C. for 20.00 min.
Centrifuge at 0 rpm for 4 hours.

The centrifugal isolation rock is manufactured by Hitachi Koki S! Use CR-268.

In each of the above cells, the particulate rubbery polymer, which is lighter than the solvent used, floats on the liquid surface, and the particulate rubbery polymer, which is thicker than the solvent, settles to the bottom of the cell. From this cell, a portion containing the floating rubbery polymer and a portion containing the precipitated rubbery polymer are separately separated as samples. Transfer these samples to separate Erlenmeyer flasks and
~ In order to remove the solvent of the F solution, the polystyrene mixture was precipitated in methanol by the reprecipitation method, and after the precipitation,
dry.

The materials obtained by drying each (a mixture of rubbery polymer and polystyrene) were again transferred to seven triangular racks, and the polystyrene mixture was dissolved and dispersed in a methyl ethyl ketone/acetone solution, and then transferred to a cell. and centrifuge (20+00 rpm for 5 hours). The centrifuged precipitate is a particulate rubbery polymer. The supernatant liquid was poured into methanol and the resulting precipitate was filtered and dried, and the rubber-like polymer was removed and the polystyrene in the matrix part was fractionated and weighed to form particles. The density distribution curve of the rubbery polymer is drawn. The fact that there is no particulate rubber-like polymer with a density of 0.96 or less is due to the fact that as a result of the fractional shaking by centrifugation in liquids A and B, there is virtually no floating del, and furthermore, the subsequent methyl ethyl ketone/acetone In liquid centrifugation, when liquids A and B are used as solvents, the supernatant collected contains virtually no rubbery polymer, based on the above analytical results.

(Example) In the following examples and comparative examples to be compared thereto, parts mean parts by weight unless otherwise specified.

Example 1 Polybutane rubber manufactured by Asahi Kasei Co., Ltd., trade name Asaprene 7
55A) was dissolved in 82.5 parts of styrene and 7.5 parts of ethylbenzene, and 0.0615 parts of tert-butylbaroxybenzene (the above polybutadiene rubber, styrene and ethylbenzene) was added as a polymerization initiator. The total amount is 100 parts, and the proportions relative to this are mixed. This raw material solution was continuously supplied at a rate of 82 parts per hour to a complete mixing type first reactor having an internal volume of 258 tubes and equipped with a double helical blade stirrer. In this reactor, the temperature was 102° C., and the rotation speed of the stirring blade was 80 rpm. The polymerization conversion rate of the product at the outlet of this reactor was 23%, and when observed with a phase contrast microscope, the rubber was found to be particulate.

Separately from this, styrene was continuously fed at a rate of 46 parts per hour to a second reactor of the same type as in the first reaction, which was a complete mixing type but had an internal ¥f product of 156. In the second reactor, the temperature is 115°C, and the rotation speed of the stirring blade is 80 rpm.
The polymerization conversion rate of the product at the outlet of this reactor was 20%.

The polymerization liquids continuously taken out from the product outlets of the first reactor and the second reactor immediately have an internal volume of 3
The mixture was introduced into a complete mixing type Pt53 reactor equipped with 8 double helical ribbon blade stirring rocks. In this ln3 reactor, the temperature is 110 °C and the stirring blade is 100 rpm.
It was operated at a rotational speed of

(as described above), combine the polymerization liquid containing rubber particles from the first reactor and the styrene partial polymerization liquid containing no rubber from the second reactor, and mix and stir in the PjS3 reactor. It was observed that, as a result, there were no large-sized rubber particles, the rubber particle size became uniform, and the particle size distribution became narrower. Raw at the outlet of the r53 reactor! The polymerization conversion rate of & was 26%.

The product coming out of the third reactor is 2(2(
2) plug flow type reactors, and further polymerization is continued.

This plug flow reactor has eight cylindrical stirring blades with a small height relative to the diameter. The stirring chamber consists of a structure separated by seven shell ant-tibe type heat exchangers that connect the stirring chambers. In addition, as a result of a separate test using a tracer and a delta response method for the first stage of this plug flow type reactor, it was found that the flow rate was 12. It was actually measured that at v time, the equivalent ff1I& is almost the same as that of IFl[ as a plug flow reactor with 11'!fJ.This equivalent number of tanks does not change substantially even if the flow rate is changed. Since the plug flow type reactor in this example consists of two plates (two units), the equivalent number of tanks in the complete mixing tank array model is 22.

In the first stage of the two-stage plug 7o-type reactor, the reaction temperature was 121°C at the inlet and 128°C at the outlet, the rotation speed of the blade was 15N↑10 rpm, and the polymerization conversion rate was 65% at the outlet.
Met. In the two-stage reactor, the reaction temperature was 130° C. at the inlet and 160° C. at the outlet, and the rotational speed of the stirring blade was 5 rp-, and the polymerization conversion was 0% from 1. At the inlet of the second stage reactor, 1.0 part of mineral oil and 0.05 part of triethylene glycol-bis(3-(3
-L-phthyl-5-methyl-4-hydroxyphenyl)
A lubricant and stabilizer such as Propione) 1 was added along with a small amount of styrene.

The polymerization liquid taken out from the reaction mixture outlet of the two-stage Bufugu 70-type reactor is heated in a multi-tube via a pressure regulator, and then reduced to 15+emHg.
A depressing chamber heated to 0℃? The styrene and V solvent ethylbenzene, etc. are removed by flashing, and the devolatilization chamber 11 is
One part was sent to an extruder by a screw, taken out as a strand from the die, and cut into a cut with a cutter to form a U (fat end).

= tyyutm Helle) Jf Approximately 500pp Volatile matter was removed to the point where only styrene and ethylbenzene remained.

The properties and performance of the rubber-modified styrene resin thus obtained were evaluated as follows.

■ Regarding rubber particles dispersed in FM fat, we took an electron microscopic photograph using an ultra-thin section method, observed the morphology of the rubber particles in the photograph, and measured the weight-independent particle diameter and number average particle diameter. It was measured by a photoprecipitation method using a Model 3000 Particle Analyzer (Louisville, Kentucky, USA), and calculated using the following formula.

Tnffi average particle diameter (Dw)=ΣnD”/ΣnD
Number average particle diameter (DN)=ΣnD/ΣnIn the above formula, D is the diameter of the rubber particle, and n is the ratio of the diameter of the rubber particle.

The rubber particle size distribution is based on the formula (D*/Ds).

■ Density of rubber-like polymer (as mentioned above) ■ Gloss (%) A test piece was obtained by injection molding at a cylinder temperature of 200°C, and the central part of the test piece (751 x 1 f 30 mm x 2.6 -) was determined according to JIS Z8741 (incidence angle GO”)
Gloss was measured according to the following.

(2) Falling weight impact strength (kg·C-): Measured using an injection molded test piece for gloss measurement using a DuPont type falling weight l1iy's test rock.

■Izotsu ms strength (kg・gukyo/C): JIS
Measured according to K71tO (notched).

Comparison Ml Polybutadiene rubber (manufactured by Asahi Kasei Co., Ltd., trade name Asabrene 7
558) 6.5 parts of styrene 8G￥S and 7.5 parts of ethylbenzene, and as polymerization initiators 0 and 15 parts of OG (per 100 parts of total amount of styrene, ethylbenzene and polybutadiene) ) mixed with

This raw material liquid was transferred to a first-degree reactor equipped with a chikuful helical aPA base with an internal volume of 40 L and a draft chamber.
It was fed at a rate of 287 hours. In this reactor, the temperature was 102°C and the rotational speed was 100 rpu.The polymerization conversion rate of the product at the outlet of the reactor was 24%, and the rubber was particulate.

The polymerization liquid discharged from the rjS1 reactor was directly led to a two-stage plug flow reactor without passing through a small complete mixing reactor with a short residence time. After using the plug flow reactor, four experiments were performed under the same conditions as in Example 1 to obtain resin products.

Comparative Example 2 The rotation speed of the stirring blade of the first reactor with internal volume No. 25 was set to 90 rp- by the operation of Example 1, and the polymerization liquid extracted from the first reactor and the second reactor outlet was piped. 2 and directly without passing through the complete mixing type third reactor with short residence time.
A resin product was obtained by operating under the same conditions as in Example 1 except that the reactor was introduced into a plug-flow type reactor.

Comparative Example 3 The first reactor and second reactor with internal volumes of 258 and 152 in Example 1 were replaced, and the reactor with an internal volume of 15 L was used as the first reactor, and this reactor was used to process polybutane rubber. A styrene and ethylbenzene solution was used in a second reactor having an internal volume of 258, and styrene was polymerized in this reactor.

The temperatures in the first reactor and the second reactor are 102°C and 115°C, respectively, and the rotational speed of the stirring blade is 14% and 3°C, respectively.
3%, and the rubber was not granulated in the first reactor. A resin product was obtained under the same conditions as in Example 1 from the third reactor onward, which was a small complete mixing type with a short residence time.

Comparative Example 4 Instead of the first reactor with an internal volume of 252 mm used in Example 1, a reactor with an internal volume of 402 mm and equipped with a double helical VA stirring rock with a V-7 tube was used. The temperature in this ffN reactor was 102° C., the rotational speed of the stirring blade was 120 rpm, the single polymerization conversion rate was 37%, and the rubber was particulate.

Other than that, a resin product was obtained under the same conditions as in Example 1, but the polymerization conversion rates at the outlets of the first-stage and second-stage plug flow reactors were 70% and 92%, respectively.

Comparative Example 5 The same rubber solution as in Example 1 was fed at a rate of 4.11 hours to a 11 reactor of content M159 equipped with a draft tube and double helical blades.

The temperature was 102 DEG C. and the rotational speed of the stirring blade was 80 rpm.The 1 m conversion rate was 23%, and the rubber had become particles.

Separately, styrene was fed at a rate of 2.48/h into a second reactor with an internal volume of 9e and equipped with double helical blades. The temperature is 115°C, and the rotation speed of the stirring blade is 80 rpm.
Met. After the Fa flow was combined and passed through a small complete mixing type third reactor with a short residence time, a part of the liquid was pumped out of the system using a pump, and the flow rate was set at 6 n/hr. The temperature at the inlet was 120°C and the temperature at the outlet was 164°C in 1 reaction 2 which was directly led to the 2nd stage plug flow reactor without passing through the 1st stage plug flow reactor in Example 1.
The polymerization conversion rate at the outlet was 90%.

From this point on, the same operations as in Example 1 were carried out to obtain a resin product.

Comparative Example 6 The same rubber solution as in Example 1 was fed at a rate of 12.84/hr into a first reactor of content ML404 equipped with a pilaf tube and double helical blades. The temperature in this first reactor was 102°C, and the rotation speed of stirring tf'5H was 80°C.
``The FFI Imaichi Imaichi rate was 3%, and the rubber had become particles.

Separately, styrene is heated at a speed of 6.4g/113g with a draft tube and internal double helical blades.
A second reactor with a volume of 25 t was fed.

The temperature in this second reactor was 115°C, and the rotational speed of the stirring blade was 80 p-.6 Both streams were combined and passed through a small third reactor with a short residence time, and then the liquid A portion of the reactor was discarded out of the system using a pump and introduced into a two-stage plug flow reactor at a flow rate of 16 L/hour.From this point onwards, operations were carried out under the same conditions as in Example 1 to obtain a +jl fat product. The polymerization busy rates at the outlets of the first-stage and second-stage plug flow reactors were 52% and 82%, respectively.

Table 1 shows the m conditions v1 of the above examples and comparative examples, and Table 2 shows the evaluation results of the obtained I1w products.

Example 2 The operation was carried out under the same conditions as in Example 1 except for the following points. That is, the temperature of the first reactor was set to 100°C. 1st reaction 4
The polymerization conversion rate of the reaction product at the outlet is 20%,
The rubber had become particulate. Also, the temperature of the Pt52 reactor is 1
The temperature was 17° C., and the polymerization conversion rate of the product at the outlet of this reactor was 23%. The polymerization liquids taken out from the first reactor and the second reactor were combined and sent to a small third reactor with a residence time of 0.42 hours, the same as in Example 1. The stirring speed of the stirring blade was 90 rpm. The rest is the same as in Example 1.

Example 3 The process was repeated under the same conditions as in Example Cf1t except for the following points.

First, the polymerization initiator mixed in the rubber solution charged into the first reactor was changed to 0.056 parts of tertiary-butyl peroxyacetate (50% pure J Bun product), and the temperature in the first reactor was set to 100°C. did. The polymerization conversion rate of the reaction product at the 4th outlet of the first reaction was 23%, and the rubber was particulate.

The temperature of the rjS2 reactor was 115° C., and the polymerization conversion rate of the product at the outlet was 20%.

The polymerization liquid taken out of the first reactor and the second reactor is combined and sent to a small R53 reactor with a short residence time, where stirring is carried out at a speed of 90 or 0 with a stirring blade. Ta.

In the first-stage reactor of the following two-stage plug flow reactor, the inlet temperature was 120 °C, the outlet temperature was 130 °C,
The polymerization conversion rate was 64% at the outlet. In addition, the second stage reactor has an inlet temperature of 133°C and an outlet temperature of 170°C.
The polymerization conversion rate was 89% at the reactor outlet. The process was repeated under the same conditions as in Example 1 except for the above.

Above '5! The operating conditions for Examples 2 and 3 are shown in Table 3, and the evaluation of the obtained products is shown in Table 4.

Table Pt54 Table (Effects of the Invention) Conventionally, when rubber-modified styrenic resins are produced by a continuous process, the resulting products have lower quality, especially mechanical properties such as impact resistance, than those produced by a batch process. Although it was not superior in terms of strength or appearance such as gloss,
According to the present invention, a rubber-modified styrenic resin having a quality equal to or higher than that of a patch-type product can be obtained by a continuous process.

Procedural correction divination (voluntary) April q, 1990

Claims (3)

[Claims] (1) A raw material solution mainly composed of styrene monomer and rubbery polymer is continuously charged into a complete mixing type first reactor to carry out a polymerization reaction, while a raw material solution mainly composed of styrene monomer The raw materials are continuously charged into a second reactor of a type that can be used for a polymerization reaction to carry out a polymerization reaction, and products are continuously derived from the first reactor and the second reactor, respectively. is simultaneously introduced into a complete mixing type third reactor having a shorter residence time than the first reactor to proceed with the polymerization reaction, and the product continuously drawn out from this third reactor is plugged. A method for continuously producing a rubber-modified styrenic resin by introducing the resin into a flow type reactor to increase the polymerization conversion rate, and then devolatilizing unreacted monomers from the reaction product, the method comprising: The rubber-like polymer in the product derived from the third reactor has already been granulated, but at the outlet of the third reactor, the polymerization conversion rate from monomer to polymer exceeds 30%. Furthermore, the plug-flow reactor is composed of one reactor or multiple reactors connected in series, and the equivalent number of tanks in the complete mixing row model is 15.
A method according to the above, characterized in that in this plug flow type reactor, polymerization is carried out to a polymerization conversion rate of 85 to 95%. (2) The method according to claim 1, wherein the polymerization is carried out in a complete mixing type first reactor until the rubbery polymer becomes particles. (3) A raw material solution mainly composed of styrene monomer and rubbery polymer is continuously charged into a complete mixing type first reactor to carry out a polymerization reaction, while a raw material solution mainly composed of styrenic monomer and rubbery polymer is The raw materials are continuously charged into a second reactor of a type that can be used for a polymerization reaction to carry out a polymerization reaction, and products are continuously derived from the first reactor and the second reactor, respectively. is simultaneously introduced into a complete mixing type third reactor having a shorter residence time than the first reactor to proceed with the polymerization reaction, and the product continuously drawn out from this third reactor is The polymerization conversion rate is increased by introducing the reaction product into a plug flow type reactor consisting of multiple reactors connected in series or in series, and the equivalent number of tanks is 15 or more in a complete mixing tank array model, and then the reaction product is Modified rubber that is produced continuously by devolatilizing unreacted monomers from a rubber compound and substantially does not contain rubbery polymer particles with a density of 0.96 or less at 25°C. Styrenic resin composition