JP2002114886A - Rubber-modified copolymeric resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded article having both shock resistance, oil-resistance and transparency. SOLUTION: A rubber-modified copolymeric resin composition containing a rubber-modified copolymer resin which is obtained by continuous block polymerization of styrene, methyl methacrylate and acrylonitrile in the presence of a styrene-butadiene copolymeric rubber having 17 mol% of 1,2-vinyl bond and having a weight ratio of styrene/butadiene of 35/65, and a plasticizer as essential components. The rubber-modified copolymeric resin composition has a percentage content of toluene-insoluble components of 4-22 wt.% at 25 deg.C, a swelling index with toluene of 11-19 at 25 deg.C and a ratio of (percentage content of toluene- insoluble components/swelling index) of 0.20-1.20 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to an improved rubber-modified copolymer resin composition, and more particularly to a styrene monomer and an alkyl (meth) acrylate in the presence of a specific styrene-butadiene copolymer rubber. The present invention relates to a rubber-modified copolymer resin composition containing a rubber-modified copolymer resin which is obtained by graft copolymerization of an ester and (meth) acrylonitrile and is excellent in oil resistance and falling weight impact strength.

[0002]

2. Description of the Related Art Conventionally, ABS resin is known as a resin having excellent impact resistance and oil resistance.
As a material obtained by adding transparency to this ABS resin, a transparent AB
S resin has been industrialized.

As such a transparent ABS resin, for example, JP-B-46-40688 and JP-A-57-30 are disclosed.
No. 714 describes a method for producing a resin in which styrene, methyl methacrylate and acrylonitrile are graft-polymerized to a styrene-butadiene copolymer rubber.

[0004]

However, none of the copolymer resins obtained by the process described in the above-mentioned prior art has sufficient impact resistance, and the styrene content of the styrene-butadiene copolymer rubber is low. Was less than 25% by weight, so that sufficient transparency could not be obtained. On the other hand, when such a styrene-butadiene copolymer rubber is used, a large amount of methyl methacrylate must be used in order to improve the transparency, and as a result, the oil resistance is lowered and the transparency is lowered. Was not enough.

An object of the present invention is to provide a molded article excellent in impact resistance, transparency and oil resistance.

[0006]

Means for Solving the Problems The present inventors have made intensive studies in view of such a situation, and as a result, in the presence of styrene in a styrene-butadiene copolymer rubber, a styrene monomer, an alkyl (meth) acrylate A rubber-modified copolymer resin obtained by graft-copolymerizing an ester and (meth) acrylonitrile and a plasticizer are essential components. That is, the toluene-insoluble content, the swelling index due to toluene, and the ratio are within a specific range. In the case, it has been found that in the copolymer resin, excellent performance is exhibited because the grafting ratio of the copolymer rubber and the degree of crosslinking are improved.
The present invention has been completed.

That is, the present invention relates to a method for preparing a styrene-based monomer (meth) in the presence of a styrene-butadiene copolymer rubber.
The rubber-modified copolymer resin obtained by graft copolymerization of an alkyl acrylate and (meth) acrylonitrile and a plasticizer are essential components, and the toluene-insoluble content at 25 ° C. is 4 to 22% by weight and 25%. The present invention relates to a rubber-modified copolymer resin composition having a swelling index of 11 to 19 and a toluene-insoluble content / swelling index of 0.20 to 1.20% by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber-modified copolymer resin composition of the present invention comprises a styrene monomer (B) and an alkyl (meth) acrylate (C) in the presence of a styrene-butadiene copolymer rubber (A). (Meth) acrylonitrile (D)
And a plasticizer as essential components, a toluene-insoluble content at 25 ° C. of 4 to 22% by weight, and a swelling index with toluene of 11 at 25 ° C.
To 19 and a toluene insoluble content / swelling index of 0.1.
Although the content is 20 to 1.20% by weight, when the rubber-modified copolymer resin composition satisfies this range, a molded article excellent in impact resistance, transparency and oil resistance can be obtained.

In the styrene-butadiene copolymer rubber (A) used in the present invention, the ratio of 1,2-vinyl bonds in the unsaturated bonds based on butadiene, which is an essential component, is 1%.
It is preferably 4 to 30 mol%, more preferably 16 to 25 mol%, and the rest is cis and trans bonds. When a styrene-butadiene copolymer rubber having a 1,2-vinyl bond ratio of less than 14 mol% is used, the content of toluene-insoluble components in the rubber-modified copolymer resin decreases,
If a product having excellent transparency and impact resistance cannot be obtained, and if the content exceeds 30 mol%, crosslinking at a high temperature during production proceeds, and the balance between the grafting ratio and the degree of crosslinking is lost. In addition, since the rubber elasticity is reduced, a product having excellent impact resistance cannot be obtained.

The styrene-butadiene copolymer rubber (A) is not particularly limited as long as it satisfies the above conditions, but is obtained, for example, as follows. That is, a styrene monomer and a butadiene monomer are mixed with n-solvent in a non-polar solvent such as hexane and cyclohexane.
It can be produced by solution polymerization in the presence of a metal catalyst such as butyllithium and tetrahydrofuran. At this time, since the proportion of the 1,2-vinyl bond in the unsaturated bond based on butadiene increases as the use amount of tetrahydrofuran increases, the styrene-butadiene copolymer rubber used in the present invention is adjusted by adjusting the use amount. Is obtained.

The copolymer rubber (A) used in the present invention
As described above, the ratio of 1,2-vinyl bonds among the unsaturated bonds based on butadiene is 14 to 30 mol%, and further, those having a bound styrene content of 30 to 55 mol% are used. It is preferable because the transparency and oil resistance of the molded product can be significantly improved. Above all, a styrene content of 30 to 45% by weight is more preferable because this effect becomes remarkable. Here, the styrene content is a percentage of the mass of the raw material styrene with respect to the mass of all the monomers constituting the copolymer rubber (A).

The copolymer rubber (A) thus obtained
Is a 1,4-cis bond or a 1,4-trans bond other than the 1,2-vinyl bond among the butadiene-based unsaturated bonds, but their proportion among the butadiene-based unsaturated bonds is Having a 1,4-cis bond of 20 to 4 respectively.
It is preferable that 0 mol%, on the other hand, 35 to 65 mol% of 1,4-trans bonds be used, since the effect of improving impact resistance is excellent.

The bonding mode of styrene and butadiene in the copolymer rubber (A) includes a random bond and a block bond, both of which can be used. Among them, the block bond is preferable.

As the above-mentioned copolymer rubber (A), those having a 5% by weight styrene solution viscosity of 5 to 40 centipoise are more effective in improving the impact strength and the rubber particle diameter can be easily controlled during production. Preferred, especially 25
It is preferable that the viscosity of the 5% by weight styrene solution at 9C is 9 to 30 centipoise and the Mooney viscosity at 100C by using an L rotor is 20 to 80.

Styrene monomer (B) used in the present invention
As styrene, α-methylstyrene, o-
Methyl styrene, m-methyl styrene, p-methyl styrene, ethyl styrene, isobutyl styrene, tertiary butyl styrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-chlorostyrene,
Examples thereof include m-chlorostyrene and p-chlorostyrene, and among them, styrene is preferred from the viewpoint of excellent transparency.

The alkyl (meth) acrylate (C) used in the present invention is an essential component for significantly improving the transparency of the rubber-modified copolymer resin of the present invention. For example, methyl (meth) acrylate, (meth) methyl ) Ethyl acrylate,
Examples thereof include n-butyl (meth) acrylate, and among them, methyl (meth) acrylate is particularly preferable because its effect is further improved.

The (meth) acrylonitrile (D) used in the present invention is specifically acrylonitrile,
Methacrylonitrile is mentioned.

The above copolymer rubber (A), styrene monomer (B) and alkyl (meth) acrylate (C)
And the ratio of (meth) acrylonitrile (D)
The weight ratio of (A) / [(B) + (C) + (D)] is 3/97 to 15/85.
And (A) for the sum of (B), (C) and (D)
Is 30 to 70% by weight, (B) is 20 to 60% by weight,
The range where (C) is 2 to 30% by weight is preferable in that a material having excellent transparency, strength and oil resistance can be obtained.

A method for graft copolymerizing a styrene monomer (B), an alkyl (meth) acrylate (C) and (meth) acrylonitrile (D) in the presence of a styrene-butadiene copolymer rubber (A) Is a method of preparing a styrene monomer (B), an alkyl (meth) acrylate (C) and a (meth) in the presence of the copolymer rubber (A).
Acrylonitrile (D) is used as an essential component, and, if necessary, together with other copolymerizable monomers.
The graft copolymerization may be carried out by suspension polymerization, solution polymerization or bulk polymerization. Among them, bulk polymerization is preferable in terms of productivity and cost.

In particular, in a continuous bulk polymerization line incorporating a stirred reactor and a tubular reactor in which a plurality of mixing elements having no moving parts are fixed, continuous mixing is performed while performing static mixing by the tubular reactor. The bulk polymerization is preferred in that the rubber particle diameter is small, the polymer composition can be controlled uniformly, and a rubber-modified copolymer resin excellent in transparency and impact resistance can be efficiently produced.

The other copolymerizable monomers used herein include, for example, vinyl / cyan compounds such as (meth) acrylonitrile; and polymerizable unsaturated fatty acids such as itaconic acid, maleic acid, fumaric acid, crotonic acid, and cinnamic acid. N-
Such as methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-octylmaleimide, N-isopropylmaleimide, N-phenylmaleimide, Np-bromophenylmaleimide, No-chlorophenylmaleimide, and N-cyclohexylmaleimide. Maleimides; unsaturated carboxylic anhydrides represented by maleic anhydride, itaconic anhydride, citraconic anhydride, etc .; containing amino groups such as allylamine, aminoethyl (meth) acrylate, and aminopropyl (meth) acrylate. Unsaturated compounds; acrylamide compounds such as acrylamide and N-methylacrylamide;

Hereinafter, continuous bulk polymerization incorporating a stirred reactor and a tubular reactor having a plurality of mixing elements without moving parts fixed inside (hereinafter abbreviated as a tubular reactor having a static mixing element) will be described. An example of a method for producing a rubber-modified copolymer resin using a line will be described with reference to the drawings.

FIG. 1 is a process diagram showing an example of a continuous bulk polymerization line incorporating a tubular reactor having a static mixing element. (A) supplied by a plunger pump (1) in a supply line (I),
The mixed solution containing (B), (C) and (D) as essential components is first sent to a prepolymerization line (II) having a stirrer reactor (2), and subjected to initial graft polymerization under stirring,
By the gear pump (3), it is sent to the polymerization line (III) having the tubular reactors (4), (5) and (6) having the static mixing elements and the gear pump (7), and the initial polymerization is performed. The outlet of the initial polymerization line (III) is divided into two parts, and most of the polymerization liquid subjected to the initial polymerization passes through the reflux line (V) and returns to the initial polymerization line (III). It is circulated in a circle formed with the line (V) (hereinafter referred to as a circulation polymerization line). The remaining polymerization liquid flows into a main polymerization line (IV) in which tubular reactors (7), (8) and (9) each having a static mixing element are connected in series, and undergoes main polymerization there.

In addition, by combining the pre-graft polymerization in the pre-polymerization line (I), that is, the pre-graft polymerization in the agitated reactor (2), and the circulation polymerization line, the rubber particles are not subjected to excessive shearing, More efficient miniaturization of
At the same time, it is preferable in that the polymer composition in the polymerization step can be made uniform. In the pre-graft polymerization in this case, the total polymerization conversion of the styrene monomer (B), the alkyl (meth) acrylate (C) and the (meth) acrylonitrile (D) is determined at the outlet of the reactor (2). 10-30
%, Preferably 14 to 26% by weight.

The stirring reactor (2) includes, for example, a stirring tank reactor, a stirring tower reactor, and the like. The stirring blades include, for example, an anchor type, a turbine type, a screw type, and a double helical type. A stirring blade such as a mold may be used.

In the present invention, a solvent may be used to reduce the viscosity of the mixed solution in the reactor, and the amount of the solvent used is 5 to 20 parts by weight based on 100 parts by weight of the total amount of the raw material monomers. . As the type of the solvent, toluene, ethylbenzene, xylene and the like which are usually used in the bulk polymerization method are suitable.

In the present invention, it is preferable to add a chain transfer agent to the mixed solution for controlling the molecular weight of the rubber-modified copolymer resin. The amount of the chain transfer agent to be added is usually 0.05 to 0.5 based on 100 parts by weight of the total of the raw material monomers.
Range of parts.

The rubber particles in the mixed solution in the circulation polymerization line are statically mixed and stabilized while circulating in the circulation polymerization line, and the particle diameter is fixed. In this case, the reflux ratio (R) and (B) of the mixed solution in the circulating polymerization line,
The total polymerization conversion of (C) and (D) is an important factor.

The reflux ratio R is the flow rate of the mixed solution refluxing in the circulating polymerization line without flowing out to the main polymerization line (V).
(Liters / hour) and the flow rate F2 (liters / hour) of the mixed solution flowing from the circulation polymerization line (I) to the main polymerization line (V), the reflux ratio R = F1 / F
F2 is in the range of 3 to 15, especially the pressure loss in the tubular reactor is small, the resulting rubbery polymer particles are stable, the particle size can be reduced, and the rubber-modified copolymer resin The range of R = 5 to 10 is particularly preferable in that the content ratio of (B), (C) and (D) can be kept constant.

In the graft polymerization in the circulation polymerization line, the total polymerization conversion of (B), (C) and (D) at the exit of the circulation polymerization line is usually 35 to 55% by weight,
The polymerization is preferably carried out so as to be 40 to 50% by weight. A suitable polymerization temperature is 120 to 135 ° C.

The mixed solution graft-polymerized in the circulation polymerization line is then supplied to the main ring polymerization line (V), usually at a polymerization temperature of 140 to 160 ° C. and the total of (B), (C) and (D). Graft polymerization is carried out continuously until the conversion reaches 60 to 80% by weight. Next, the mixed solution is sent to a preheater and then to a devolatilization tank by a Kia pump (11) to remove unreacted monomers and a solvent under reduced pressure.
The desired rubber-modified copolymer resin is obtained by pelletizing. At this time, it is preferable to perform the preheating and the devolatilization under the condition that the increase in the conversion rate in the preheater and the devolatilization tank is 10% by weight or less.

As the plurality of mixing elements fixed inside the tubular reactor having the static mixing element used in the present invention, for example, the flow of the polymerization liquid flowing into the pipe is changed and the flow direction is changed, Is repeated to mix the polymerization liquid. As such a tubular reactor, for example, SMX type, SMR
Sulzer-type tubular mixers, Kenix-type static mixers, and Toray-type tubular mixers are preferred.
FIG. 2 shows an example of a tubular reactor having such a static mixing element. The number of these tubular reactors to be incorporated in the initial polymerization line (III) or the main polymerization line (V) is not particularly limited in the case of the tubular reactor as described above, since it differs depending on the length, the structure of the mixing element, and the like. 4 to 15 tubular reactors having 4 or more mixing elements,
Preferably, 6 to 10 pieces are used in combination. Among them, the number of the tubular reactors to be incorporated in the circulation polymerization line (I) is usually 1 to 10, preferably 2 to 6. In the mixed solution used as a raw material in the present invention, if necessary, an organic peroxide that releases free radicals when decomposed as a polymerization initiator is added, whereby grafting and reaction can be promoted at a relatively low temperature. It is preferred. The added amount is 0.005 to 0.0 with respect to 100 parts by weight of the total amount of the raw material monomers.
The range is 4 parts by weight. As the organic peroxide used herein, those having a temperature at which the half life is 10 hours and 75 to 170 ° C. are preferable, and specific examples thereof are 1,1-di-t-butyperoxycyclohexane and 1,1- Di-t-butylperoxy-3,3,5-trimethylcyclohexane, 2,2-di-t
-Butylperoxyoctane, n-butyl-4,4-di-t
Peroxyketals such as -butylperoxyvalerate and 2,2-di-t-butylperoxybutane; t-butylperoxyacetate, t-butylperoxy-3,5,5-
Trimethylhexanoate, t-butyl peroxy laurate, t-butyl peroxybenzoate, di-t-
Butyl diperoxyisophthalate, 2,5-dimethyl-2,
5-dibenzoylperoxyhexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, di-t-butyl peroxide, sicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and the like Peroxyesters and the like can be mentioned, and they are used alone or in combination of two or more.

The mixed solution used in the present invention may contain, if necessary, known antioxidants, chain transfer agents, release agents such as long-chain fatty acids, esters or metal salts thereof, and known oils such as silicone oil. Additives may be used in combination.

The rubber-modified copolymer resin thus obtained is preferably added with a plasticizer during the polymerization step to form the rubber-modified copolymer resin composition of the present invention. Each of the compositions has a toluene insoluble content at 25 ° C of 4 to 22% by weight, a swelling index with toluene of 11 to 19, and a toluene insoluble content / swelling index of 0.20 to 1.20. weight%
It satisfies the condition.

Further, the average rubber particle diameter of the styrene-butadiene copolymer rubber in the composition is preferably 0.05 to 0.80 μm, and particularly, from the viewpoint of excellent transparency and impact resistance of the molded article. 0.10 to 0.60 μm is preferred.

Further, as the rubber-modified copolymer resin,
Styrene monomer which is a matrix phase in the resin,
The copolymer of alkyl (meth) acrylate and (meth) acrylonitrile has a weight average molecular weight (Mw) of 100,000 to 160,000, and a ratio Mw / weight average molecular weight (Mw) to number average molecular weight (Mn). Those having Mn of 1.8 to 2.5 are preferable, and among them, the weight average molecular weight (Mw) is 12
Those having a size of 150,000 to 150,000 are particularly preferred.

The plasticizer is an essential component of the composition of the present invention which remarkably improves the flowability of the rubber-modified copolymer resin during melting without lowering the transparency of the molded article. The plasticizer is not particularly limited, but is preferably an ester-based plasticizer or a polyester-based plasticizer. Among them, dibutyl phthalate and butylbenzyl phthalate are preferred because the above-mentioned effects are remarkable.

The composition of the present invention may further contain commonly used antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents, foaming agents, reinforcing materials and the like.

Among these, preferred are, for example, mineral oil, organic polysiloxane, higher fatty acids and metal salts thereof, hindered phenolic antioxidants,
Glass fiber and the like can be mentioned, and each can be used alone or in combination.

Further, the rubber-modified copolymer resin composition of the present invention may further comprise injection molding, uniaxial extrusion molding, biaxial stretching extrusion molding, inflation extrusion molding, profile extrusion molding, vacuum molding, air pressure molding, blowing. Various molded articles can be used by molding methods such as molding. Its applications are wide-ranging, for example, parts of household appliances and appliances such as radio cassettes, audio players, and video tape recorders; various parts of OA equipment such as copiers, printers, facsimiles, and personal computers; IC carriers and magazines; Used as food containers; medical instrument parts; blister packages, food packaging containers, and the like. Further, the rubber-modified copolymer resin of the present invention, if necessary, polystyrene resin, rubber-modified polystyrene resin, AS resin, ABS resin, styrene-methyl methacrylate copolymer resin, rubber-modified styrene-methyl methacrylate copolymer resin, (Meth) acrylic resin, styrene-maleic anhydride copolymer resin, styrene-
A thermoplastic resin such as a (meth) acrylic acid copolymer resin, a polycarbonate resin, and a vinyl chloride resin may be appropriately added.

The methods for measuring the average particle size, the content of toluene-insoluble matter and the swelling index of toluene of the rubbery polymer are described below. 1. Average particle size of rubbery polymer in resin Take a transmission electron micrograph of the resin by ultra-thin section method,
The particle diameter of 00 particles was measured, and the average particle diameter was determined by the following equation.

Average particle size = ΣniDi4 / ΣniDi3 (where ni is the number of rubber particles having a particle size Di). Toluene insoluble content and swelling index due to toluene 1 g of the rubber-modified copolymer resin was accurately weighed, and 100 m
The solution was transferred to a centrifuge tube, centrifuged at 12,000 rpm or less at 12,000 rpm for 15 minutes, and the supernatant was removed by decantation, followed by swelling with toluene. Measure the weight of the insoluble matter. Next, it is dried for 24 hours in a vacuum dryer at 60 ° C., the weight of the obtained toluene-insoluble component is measured, and the content of the toluene-insoluble component is calculated by the following equation. Toluene-insoluble content = (toluene-insoluble content / resin weight) × 100 (%) The swelling index is calculated by the following equation.

Swelling index = weight of swollen toluene-insoluble matter / weight of dried toluene-insoluble matter Measurement method of 1,2-vinyl bond ratio in copolymer rubber It was measured by infrared spectroscopy (Morello method).

[0044]

The present invention will be described more specifically below with reference to examples and comparative examples. However, all parts in the examples are parts by weight, and all percentages are percentages by weight except for the total light transmittance and the ratio of 1,2-vinyl bonds. The physical properties in the examples were measured as follows. 1) A box-shaped molded product (180 mm L 126 mm L 25 mm, wall thickness 2 mm) injection-molded using an injection molding machine (Japan Steel Works J150SSIIA) with a falling weight impact strength cylinder temperature of 240 ° C. A steel ball having a weight of 1 kg was dropped at the center thereof, and the falling weight impact strength was determined by the product of the height of the steel ball and the drop height up to the breakage. 2) Izod impact value, flexural strength and flexural modulus JIS K
Compliant with -6871. 3) A test piece having a total light transmittance and a haze value of 2 mm was prepared by an injection molding method, and the values were determined in accordance with ASTM D-1003. 4) Oil resistance test of molded article A dumbbell test piece having a length of 165 mm is fixed in an arc shape to a test jig having a length of 160 mm to give a distortion. Oil was applied to the surface of the test piece and left at 23 ° C. and 50% humidity. The appearance of the molded article after a certain time was observed. In this test, salad oil (edible soybean oil) was used.

Example 1 In this example, devices arranged as shown in FIG. 1 were used. A mixed solution containing styrene, methyl methacrylate, acrylonitrile, a rubbery polymer and a solvent is sent to a 20-liter stirred reactor (2) by a plunger pump (1), and the initial grafting is performed under dynamic mixing by a stirring blade. Polymerized. Next, this mixed solution is sent to the initial polymerization line (I) by the gear pump (3). The initial polymerization line (I) is a tubular reactor with an inner diameter of 2.5 inches in order from the inlet (30 SMX static mixers and 30 static mixing elements manufactured by Gebrüder Sulzer, Switzerland)
A gear pump (7) for circulating the mixed solution with (4), (5) and (6). An outlet is provided between the tubular reactor (6) and the reflux line (V) having the gear pump (7), following the main polymerization line (V). The same tubular reactors (8), (9) and (10) as above and a gear pump (11) are connected in series from the inlet to the main polymerization line (V).

Styrene-butadiene block copolymer rubber [5% styrene solution viscosity at 25 ° C. (hereinafter 5% SV
Abbreviated): 20 centipoise, ratio of 1,2-vinyl bonds:
17%, styrene / butadiene weight ratio: 35/65] 7 parts,
A mixed solution consisting of 45 parts of styrene, 45 parts of methyl methacrylate, 10 parts of acrylonitrile and 10 parts of ethylbenzene was prepared.
2 parts per 100 parts of dibutyl phthalate, 0.1 part of n-dodecyl mercaptan per 100 parts of the monomer mixture as a chain transfer agent and 0.1 part per 100 parts of the monomer mixture as an organic peroxide. 02 parts of t-butyl peroxybenzoate was added, and continuous bulk polymerization was carried out using the above apparatus under the following conditions.

Continuous supply of mixed solution: 10 liter / hour reflux ratio R: 7 Reaction temperature in stirred reactor (2):
Reaction temperature at 120 ° C initial polymerization line (III): 135
Reaction temperature in main polymerization line (IV): 140-160 ° C
The mixed solution obtained by the polymerization was heated to 225 ° C. in a heat exchanger to remove volatile components under a reduced pressure of 50 mmHg, and then pelletized to obtain a rubber-modified copolymer resin composition of the present invention. Table 1 shows the analytical data and measurement results of physical properties of the resin.

Example 2 Styrene-butadiene block copolymer rubber [5% SV:
10 centipoise, ratio of 1,2-vinyl bond: 19%, styrene / butadiene weight ratio: 41/59] 8 parts, styrene 5
0 parts, methyl methacrylate 35 parts, acrylonitrile 1
A rubber-modified copolymer resin composition of the present invention was obtained in the same manner as in Example 1 except that a mixed solution consisting of 5 parts and 10 parts of ethylbenzene was used. Table 1 shows the analytical data and the measurement results of the physical properties.

Example 3 Three 20-liter tank type complete reactors (i), (ii) and (iii) equipped with a helical stirring blade, a heat exchanger and a devolatilizing tank were connected in series. The polymerization reaction was carried out using a continuous reaction apparatus arranged in such a manner. A mixed solution consisting of 7 parts of styrene-butadiene block copolymer rubber similar to that used in Example 1, 45 parts of styrene, 45 parts of methyl methacrylate, 10 parts of acrylonitrile and 10 parts of ethylbenzene was prepared. Monomer mixture 100
Parts by weight of butylbenzyl phthalate and 0.1 part of n- as a chain transfer agent per 100 parts of the monomer mixture
0.02 parts of t-butylperoxybenzoate was added to 100 parts of the monomer mixture as dodecyl mercaptan and an organic peroxide, and the resulting mixture was continuously subjected to bulk polymerization using the above-described apparatus under the following conditions.

Continuous supply of mixed solution: 7 liters /
Reaction temperature in the time tank reactor (i): 125 ° C. Reaction temperature in the tank reactor (ii): 130 ° C. Tank reactor (iii)
Reaction temperature: 145 ° C. In the same manner as in Example 1, a rubber-modified copolymer resin composition of the present invention was obtained. Table 1 shows the analytical data and the measurement results of the physical properties.

Comparative Example 1 Styrene-butadiene copolymer rubber "Tuffden AS" (5
% SV is 50 cps and the ratio of 1,2-vinyl bonds is 13
%, Styrene / butadiene weight ratio of 25/75)
Parts, styrene 32 parts, methyl methacrylate 52 parts, acrylonitrile 10 parts and ethylbenzene 10 parts were prepared in the same manner as in Example 3 to obtain a rubber-modified copolymer resin composition. Table 1 shows the analytical data and the measurement results of the physical properties.

[0052]

[Table 1]

：: No cracks Δ: Many cracks
×: broken

[0054]

According to the present invention, it is possible to provide a rubber-modified copolymer resin having excellent impact resistance and oil resistance of a molded article, and furthermore, the content of bound styrene in the copolymer rubber (A). By making the specific range, a rubber-modified copolymer resin which significantly improves oil resistance and transparency of a molded article can be provided. Further, when continuous bulk polymerization is performed, the productivity is remarkably improved. The rubber-modified copolymer resin obtained by the production method of the present invention has excellent transparency, oil resistance and practical strength of falling weight impact strength, and thus can be suitably used for various molded products.

[Brief description of the drawings]

FIG. 1 is a process diagram showing an example of a continuous polymerization line incorporating a tubular reactor having a static mixing element therein. (1): Plunger pump (2): Stirred reactor (3): Gear pump (4): Static mixing element (5): Tubular reactor having a static mixing element inside (6): Static mixing Tubular reactor with elements inside (7): gear pump (8): Tubular reactor with static mixing elements inside (9): Tubular reactor with static mixing elements inside (10): Static mixing Tubular reactor having an element inside (11): gear pump (I): raw material supply line (II): prepolymerization line (III): initial polymerization line (IV): main polymerization line (V): reflux line

FIG. 2 is a cross-sectional perspective view of an example of a tubular reactor having a static mixing element therein. a: Static mixing element b: Tubular reactor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BN141 EH146 FD010 FD026 FD070 GB01 GG00 GQ00 4J026 AA17 AA68 AC11 AC16 AC32 BA05 BA08 BA27 BA31 BB04 DA02 DA08 DA18 DB05 DB15 DB26 FA03 GA09

Claims (4)

[Claims] An essential component is a rubber-modified copolymer resin obtained by graft copolymerizing a styrene monomer, an alkyl (meth) acrylate and (meth) acrylonitrile in the presence of a styrene-butadiene copolymer rubber, and a plasticizer. And the toluene insoluble content at 25 ° C. is 4 to 4.
22% by weight, swelling index with toluene at 25 ° C. is 11
To 19 and a toluene insoluble content / swelling index of 0.1.
20. 1.20% by weight of a rubber-modified copolymer resin composition. 2. The composition according to claim 1, wherein the styrene-butadiene copolymer rubber in the thermoplastic resin has an average particle size of 0.05 to 0.80 μm. 3. The composition according to claim 1, wherein the plasticizer contains an ester and a polyester plasticizer. 4. The composition according to claim 3, wherein the plasticizer is dibutyl phthalate or butylbenzyl phthalate.