JPS6045210B2 - Continuous production method for rubber-reinforced thermoplastics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous process for producing rubber reinforced thermoplastics.

In the production of rubber-reinforced thermoplastic resins, such as ABS resins and MBS resins, monomers of hard resin components, such as styrene, styrene and acrylonitrile, and styrene and methyl methacrylate, are added to the rubber-like polymer. When graft polymerization is carried out, the particles of the rubbery graft polymer are uniformly dispersed within the hard resin system and have good miscibility, resulting in molded products with excellent mechanical properties such as impact resistance and appearance. It is a well-known fact that this can be achieved.

Various methods for polymerizing rubber-reinforced thermoplastic resins, such as batch polymerization, semi-batch polymerization, and continuous polymerization, have been proposed (hereinafter referred to as "batch method" including batch method and semi-batch method). Generally speaking, when comparing batch polymerization and continuous polymerization,
It is known that the latter method is more advantageous on an industrial scale in terms of uniformity of quality and improvement of productivity. For example, in the currently known continuous polymerization method, one or several flow reactors are used to continuously collect all components such as rubbery polymers and monomers from one end of the reactor. A method for completing the graft polymerization reaction by supplying
17893, JP-A-48-79892), and a method in which a rubber-like polymer is fed to the first machine and monomer components etc. are added in portions (JP-A-49-3155\JP-A-48-798).
93) etc. However, these methods have the following drawbacks. (1) Impact resistance during high temperature molding is greatly reduced.

(2) Appearance, especially gloss, is greatly reduced during high temperature molding.
(3) It is generally difficult to obtain a high polymerization rate, and in order to obtain a high polymerization rate, it is necessary to sacrifice productivity.

These drawbacks in continuous polymerization methods are believed to arise for the reasons described below. (1) In the case of a continuous polymerization method using a tubular reactor, tower reactor, or stirred tank reactor, even if the operating conditions are skillfully determined, monomers etc. charged in the polymerization system Some of it exits the polymerization system after a relatively short period of time via a short bath.

(2) Also, for this reason, it is thought that the obtained polymer contains polymers with an extremely low degree of polymerization.

The present invention was achieved as a result of research using an industrially advantageous continuous polymerization method in order to improve the above-mentioned drawbacks. That is, the present invention is characterized by preventing short baths in the polymerization system by installing two or more batch polymerization reactors during the process of continuously polymerizing a rubber-reinforced thermoplastic resin. It is. In the method of the present invention, it is easier to obtain a higher polymerization rate than in conventional continuous polymerization methods, and the resulting polymer has good impact resistance during high temperature molding and good retention of the appearance, especially gloss, of the molded product. Next, the present invention will be explained in detail.

Rubber latex includes homopolymer latex such as polybutadiene, polyisoprene, polychloroprene, etc.
or) Rubber-like copolymers of butadiene and other monomers, such as butadiene-styrene copolymers and butadiene-α-methylstyrene copolymers. Copolymers of butadiene and vinyl monomers, such as copolymers of aromatic monomers, butadiene-acrylonitrile copolymers, butadiene-methyl methacrylate copolymers, and butadiene-butyl acrylate copolymers. It is possible to use them alone or in combination.

Furthermore, non-diene rubber-like polymers such as ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, or acrylic rubber can also be used. The monomers supplied in the presence of the rubber latex include monovinyl aromatic compounds, such as styrene, vinyl toluene, dimethylstyrene, etc., nuclear alkyl-substituted vinyl aromatic monomers, α-methylstyrene, etc. α-position substitution system,
Nuclear halogen-substituted vinyl aromatic monomers such as chlorostyrene, bromstyrene, and bromotoluene are used alone or
A mixture of one or more vinyl monomers copolymerizable with this, such as acrylonitrile, methacrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate, is used.

In the method for producing an impact-resistant resin of the present invention, the rubbery polymer is contained in the graft polymer in an amount of 5 to 8%, preferably 7 to 7% by weight.
It is desirable to use it so that the amount is %.

If the amount of rubber is less than this range, sufficient impact-resistant resin will not be obtained, and if it is too much, the polymer will become a rubber-like resin and it will be difficult to recover it in powder form. In addition, the graft resin content decreases, making it difficult to mix with the hard resin. As emulsifiers, customary anionic surfactants such as sodium or potassium laurate salts,
Fatty acid salts such as sodium or potassium stearate, sodium or potassium oleate, resinates such as disproportionated sodium or potassium rosinate, sodium or potassium salts of alkyl sulfates, sodium or potassium alkylbenzenesulfonates, etc. or a mixture of two or more of these emulsifiers, and in some cases, a nonionic surfactant may be used in combination with these emulsifiers. As the molecular weight regulator (chain transfer agent), those commonly used in emulsion polymerization, such as octyl mercaptan,
dodecyl mercaptan, tetradodecyl mercaptan,
A suitable amount of a mercaptan compound such as tertiary dodecyl mercaptan, tertiary tetradodecyl mercaptan, or normal dodecyl mercaptan is used.

Examples of the polymerization initiator include kyumene hydroperoxide, diisopropylbenzene hydroperoxide,
Organic peroxides such as diisopropylbenzene hydroperoxide and persulfates such as potassium persulfate and ammonium persulfate can be used, as well as, for example, the sodium salt of formaldehyde sulfylate, sodium sulfite, glucose, polyethylenediamine, ascorbic acid. These reducing agents can be used alone or in combination with ferrous sulfate and chelating agents such as sodium pyrrolizoate and sodium ethylenediaminetetraacetic acid.

In the present invention, the rubbery polymer latex described above,
Mix monomers, emulsifiers, molecular weight regulators, water, and polymerization initiators in quantitative ratios (heating may be performed if necessary),
Graft polymerization is carried out continuously, and in this case, as shown in Figure 1, a continuous polymerization reactor is followed by a batch-type polymerization reactor, such as a batch-type stirred tank reactor with n or more groups (n: an integer of 2 or more). to create a polymerization environment that does not cause short baths.

In Figure 1, 1 is a reactor, which is a stirring type reactor,
Any type of reactor such as a tube reactor or a tower reactor may be used, or a combination thereof may be used.

2 is a switching valve, 31,3.

, 33...3n are stirred tank reactors for batch polymerization. A stirred tank reactor is a reactor that is equipped with a stirring device, a liquid supply port, and a discharge port, and can control heating and/or cooling. In the present invention, a polymer product can be easily obtained by operating according to the procedure shown below.

It should be noted that the operating procedure shown in FIG. 1 and below shows one example of the embodiment, and it goes without saying that various commonly used conversions are possible. First, reactor 1
The above-described polymerization raw material is continuously fed, and after a predetermined average residence time, an equal amount of latex in the middle of polymerization (hereinafter referred to as polymerized latex) is continuously flowed out from the reactor 1. The polymerized latex that has flowed out is supplied to any one of the stirred tank reactors 31 to 3 by the switching valve 2. For example, when n=2: 1) Continuously supplied into the reactor 31 which is in an empty state.

At this time, a part of the polymerization raw materials to be used may be supplied at the same time. 2) When the reactor 31 is filled with polymer latex etc. to a predetermined level, the polymer latex is supplied to the reactor 32 by the switching valve 2.

At this time, a portion of the polymerization raw materials used as before may be supplied at the same time. Further, at this time, if necessary, an appropriate amount of the polymerization initiator described above may be additionally supplied to the reactor 31. 3) In parallel with the supply of polymerized latex and the like to the reactor 32, a batch polymerization reaction is allowed to proceed in the reactor 31.

4) The latex whose polymerization reaction has proceeded for a predetermined period of time in the reactor 31 immediately flows out from the reactor 31.

However, the time required from the start time of the batch polymerization reaction in the reactor 31 to the end of the outflow is the same as or shorter than the time required for filling the polymerization latex into the reactor 32. 5) When the reactor 32 is filled with polymerization latex to a predetermined level, the polymerization latex flowing out from the reactor 1 is supplied to the reactor 31 again by the switching valve 2.

At this time, as before, a portion of the polymerization raw materials used may be supplied at the same time. Further, if necessary at this time, an appropriate amount of the polymerization initiator described above may be supplied to the reactor 32 under pressure. 6) In parallel with the supply of polymerization latex to the reactor 31, a batch polymerization reaction is allowed to proceed in the reactor 32.

7) Reactor 3.

The latex, which has been polymerized for a predetermined period of time, immediately flows out of the reactor 32. The time required from the start time of the batch polymerization in the Tatami reactor 32 to the end of the outflow is the same as or shorter than the time required for filling the polymerization latex into the reactor 31. By repeating the operations described above, a polymer product can be easily obtained. When n is increased, that is, when the number of stirred tank reactors for performing batch polymerization reactions is increased, the batch polymerization time in the reactors can be lengthened.

However, it is necessary to take into consideration the effect and increase in cost due to an increase in the number of n, and it is preferable that n is 2 or more and 4 or less. of
FIG. 2 shows an example of another polymerization apparatus used in carrying out the present invention.

In Figure 2, a is a supply port for rubber-like polymer latex, b is a supply port for monomers or polymerization initiators, c is a pipe for connecting each reactor, and R-1 is a pipe for continuous polymerization. The first reactor, R-2, is a second reactor for seven continuous polymerizations, BR-1 and BR-2 are reactors for batch polymerization, and ■ indicates a switching valve. According to the method of the present invention, a high polymerization rate can be easily obtained without impairing the industrial advantages of the continuous polymerization method.
Furthermore, the polymer obtained by the method of the present invention has good impact resistance during high-temperature molding and retains the appearance, particularly the gloss, of the molded product.

The method of the present invention will be specifically explained with reference to the following Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded.

The physical property values of the resin obtained by the present invention were determined by molding test pieces under the two conditions shown in Table 1, and the impact resistance was A.
STMD-256, and gloss level is ASTMD-523
Measured according to. Table 1: Molding conditions for test pieces for measuring physical properties (1) Molding at 200°C...Cylinder temperature 2
Injection molding at 00°C (2) 280°C molding...Injection molding at a cylinder temperature of 280'C (Note) Molding machine used: Toshiba Machine 1S-80A Example 1 Reaction with a stainless steel stirrer as shown in Figure 2 Machine 4
Install the machine.

These reactors are each capable of heating and cooling, and each has an internal volume of 10e. Each reactor is equipped with one or more supply ports and connected by a vibrator. First, each reactor is purged with a nitrogen stream, and then the next R-1 feed component is supplied to reactor R-1 maintained at 65°C.
(R-1 Supply component) Polybutadiene latex, JSRO7OO787.5
gr'/hour (as solids) Water 3150gT'/hour Disproportionated Potassium Rosinate 26.25gr'/hour Styrene 647.5gr'/hour Acrylonitrile 315gr'/hour Tertiary Decyl Mercaptan 7
gr/hour Kiyumen hydroperoxide
3.5 gr''/hour Sodium formaldehyde sulfoxylate 1.05 gr'/hour Ferrous sulfate heptahydrate 0.0875 gr''/hour Disodium ethylenediaminetetraacetate
0.7 gr'/hour The above feed components were uniformly dispersed in an emulsified form in the stirred reactor R11.

This polymerized latex was introduced into reactor R-2 maintained at 75° C. to proceed with graft polymerization. The polymerized latex flowing out from reactor R-2 was introduced into reactor BR-1 or (and) BR-2, and a batch polymerization reaction was carried out under the conditions shown below. (Batch polymerization conditions) Time required for filling Batch polymerization time for 12 particles Time required for discharging 9 particles
1 powder reaction temperature
At 80 DEG C., 1.75 gr' of cumene hydroperoxide was fed at the beginning of the batch polymerization.

The polymerization conversion rates of monomers in each reactor in steady state were as shown in Table 2 below.

Graft polymer latex obtained in the above polymerization solid equivalent 1
To 00 parts by weight, 1.0 part of ditertiary butyl para-cresol as an antioxidant was added in an emulsified form, coagulated with sulfuric acid and calcium chloride, washed with water and dried to form a hard resinous polymer. A composite resin (hereinafter referred to as AS resin) was mixed and prepared so that the comb-like polymer content in the mixture was 20% to produce pellets.

Table 8 shows the results of measuring the physical properties of the resin.
Comparative Example 1 In the apparatus shown in Figure 2, the use of reactor BR-2 was stopped,
The same polymerization recipe and polymerization temperature conditions as in Example 1 were employed, except that reactors R-1, R-2, and BR-1 were used as a series of flow-type continuous polymerization devices.

However, the feed rate of cumene hydroperoxide to reactor BR-1 was 0.875 gr/hour. The temperature and polymerization conversion rate of monomers in each reactor in a steady state were as shown in Table 3 below.

Using the steady-state graft polymer latex obtained in the above polymerization, pellets were produced under the same conditions as in Example 1, and the physical properties of the resin were measured.

The results are shown in Table 8. Example 2 Using the same equipment as in Example 1, reactor R-1 is fed with the following R-1 feed components:

(R-1 Supply component) Polybutadiene latex, JSRO7OO787.5
gr/hour. (as solid content) Water 2100gr/hour Disproportionated potassium rosinate 8.75gr/hour Styrene
175gr'/hour acrylonitrile 105gr/hour, tertiary lead decyl mercaptan 3.5gr'/hour
Time Kiyumen Hydroperoxide
1.75 gr'/hour Sodium formaldehyde sulfoxylate 1.05 gr'/hour Ferrous sulfate heptahydrate 0.0875 gr'/hour Disodium ethylenediaminetetraacetate
0.7 gr'/hour 5 The polymerized latex flowing out from reactor R-1 was led to reactor R-2, and the following R-2 feed components were added to proceed with graft polymerization.

(R-2 Feed Components) Styrene 472.5gr'/hr Acrylonitrile 210gr'/hr Disproportionated Potassium Rosinate 17.5gr'/hr Tertiary Decyl Mercaptan
3.5gr/hour Kiyumen Hydroperoxide
1.75gr/hour water
1050gr/hour Latex polymerized in reactor R-2 is transferred to reactor BR-1 by switching valve.
, or (and) BR-2, and a batch polymerization reaction was carried out under the same conditions as in Example 1.

Note that 1.75 gr' of kyumene hydroperoxide was supplied at the start of the batch polymerization.

The temperature and polymerization conversion rate of monomers in each reactor in a steady state were as shown in Table 4 below.

Using the obtained graft polymer latex,
The resin was pelletized under the same conditions as in Example 1, and the physical properties of the resin were measured.

The results are shown in Table 8. Comparative Example 2 In the apparatus shown in Fig. 2, the use of reactor BR-2 was stopped and reactors R-1 and R-2 were used.
The same polymerization recipe and polymerization temperature conditions as in Example 2 were employed, except that BR-1, BR-1, was used as a series of flow-type continuous polymerization apparatuses.

However, the feed rate of cumene hydroperoxide to reactor BR-1 was 0.875 gr/hour. The temperatures and polymerization conversion rates of monomers in each reactor in steady state were as shown in Table 5 below. The steady-state graft polymer obtained by the above polymerization was pelletized under the same conditions as in Example 1, and the physical properties of the resin were measured.

The results are shown in Table 8. Example 3 Using the same equipment as in Example 1, the following R-
1 feed component.

(R-1 Feed component) Polybutadiene latex, JSRO7OO787.5gr/hour (as solid content) Water 2100gr'/hour Disproportionated potassium rosinate 8.75gr'/hour Styrene 215.78gr/hour Acrylonitrile 105gr'/hour Tershea Lead decyl mercaptan 2
．． 275gr'/hour Kiyumen Hydroperoxide
1.225 gr/hr Sodium Formaldehyde Sulfoxylate 1.05 gr''/hr Ferrous Sulfate Heptahydrate 0.0875 gr/hr Disodium Ethylenediaminetetraacetate
The polymerized latex flowing out from reactor R-1 at 0.7 gr'/hour was introduced into reactor R-2, and the following components to be supplied to R-2 were added to proceed with graft polymerization.

(R-2 Feed Components) Styrene 215.78 gr'/hr Acrylonitrile 105 gr'/hr Disproportionated potassium rosinate 8.75 gr'/hr Tertiary dicyl mercaptan
2.275gr'/hour Yumene hydronoguoxide 1.225gr'/hour Water 525gr'/hour The latex polymerized in reactor R-2 is transferred to reactor BR-1 or (and) BR-2 by a switching valve. The following ingredients were added to fill the tank to a predetermined level.

(BR-1 or (and) BR-2 Feed Components) Styrene 215.78 gr'/hour Acrylonitrile 105 Disproportionated potassium rosinate 8.75, Tertiary lead decyl mercaptan 2.
275〃Kyumen Hydroperoxide
1.225 water
525〃, the same conditions as in Example 1 were adopted for batch polymerization in reactor BR-1 or (and) BR-2.

The temperatures and polymerization conversion rates of monomers in each reactor in steady state were as shown in Table 5 below. The graft polymer obtained by the above polymerization was pelletized under the same conditions as in Example 1, and the physical properties of the resin were measured.

The results are shown in Table 8.

Comparative Example 3 Of the apparatus shown in FIG.
-1 was installed in series, and the four reactors were used as a series of flow reactors.

Reactors R-1 and R-2 were operated under the same conditions as in Example 3, and the polymerized latex flowing out from reactor R-2 was introduced into reactor BR-1, and the following BR-1 feed components were In addition, graft polymerization was allowed to proceed. (BR-1 Feed Components) Styrene 215.78gr/hr Acrylonitrile 105gr/hr Disproportionated Potassium Rosinate 8.75g″/hr Tertiary Lead Decyl Mercaptan 2.2
75gr/hour Kiyumen Hydroperoxide
1.225gr'/hour water
525gr'/hour reaction time βR-1
The polymerized latex flowing out was led to reaction 4aBR-2, and graft polymerization was further advanced.

The temperature and monomer polymerization conversion rate in each reactor in a steady state were as shown in Table 7 below. The steady-state graft polymer obtained by the above polymerization was pelletized under the same conditions as in Example 1, and the physical properties of the resin were measured.

The results are shown in Table 81. The effects of the present invention obtained from the above examples are summarized as follows.

1. The polymerization conversion rate of the method of the present invention is higher than that of conventionally known methods.

In terms of two physical properties, the products of the present invention have better impact resistance during high-temperature molding and better maintenance of the appearance of the molded product, especially the glossiness, compared to products made by conventionally known methods.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one example of the polymerization apparatus used in the production method of the present invention, and FIG. 2 is a schematic diagram showing another example of the polymerization equipment used in carrying out the production method of the present invention. 1...Reactor for continuous polymerization, 2...1
Switching valve for polymerized latex flowing out from 31,3
2,33,...3n... Stirred tank reactor for batch polymerization, a... Rubber polymer latex feed port, b... Monomer or polymerization initiator Supply ports such as c
... Vibe for connecting each reactor, R-1
...First reactor for continuous polymerization, R-2...Second reactor, BR-1, BR-2...Reactor for batch polymerization, ■... ...Switching valve.

Claims (1)

[Claims] 1. A method for continuously producing a rubber-reinforced thermoplastic resin by graft polymerizing one or more vinyl monomers in the presence of a rubbery polymer, comprising: a continuous polymerization device; Two or more batch polymerization apparatuses are installed, and the continuous polymerization operation is followed by the batch polymerization operation, and the time required from the start of the batch reaction of the polymerized latex in one batch polymerization apparatus to the end of the outflow is the remaining time. A method for producing a rubber-reinforced thermoplastic resin, characterized in that the total time for filling polymerized latex into a batch polymerization apparatus is equal to or shorter than the total time. 2. The method for producing a rubber-reinforced thermoplastic resin according to claim 1, wherein 2 to 4 batch polymerization devices are installed in a series of continuous polymerization devices to carry out the polymerization operation. 3. The method for producing a rubber-reinforced thermoplastic resin according to claim 1 or 2, wherein the polymerization is carried out in an aqueous medium in the presence of an emulsifier and a radical initiator. 4. The method for producing a rubber-reinforced thermoplastic resin according to claims 1 to 3, which comprises graft polymerizing styrene and acrylonitrile in the presence of polybutadiene latex and/or styrene-butadiene copolymer rubber latex.